Homebrew PCBs

>
> 
> Hello Homebrew Printed Circuit Group!
> 
> I have successfully modded my Epson Artisan 50 printer  Epson Printer
> Mod
> <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> this forum, want to quickly build working devices from all the many
> awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> 
> In my current project, I need to fabricate a "system-in-package" (SIP)
> module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> SMD's (resistors, capacitors, inductors, x-tal, etc).
> 
> This project requires very small SMD's and a very small and dense
> multi-layer PCB  with micro vias for fabrication.
> 
> This project well exceeds my existing "Homebrew" equipment capability to
> fabricate this module.
> 
> In assessing the demands for the size and scope of this project (for a
> "homebrew" solution) the "show stopper" was all in the  fabrication of
> the PCB itself.
> 
> Here I began my quest for a different "homebrew" solution.
> 
> Could I build this module without the complex multi-layer PCB?
> 
> Could I interconnect all SMD's (IC's and discrete's) without soldering?
> 
> 
> 
> Concept proposal:
> 
> Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> a conventional PCB.
> 
> Apply double sided releasable 3M "micro adhesive" tape covering the top
> surface of the substrate.
> 
> "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> with no PCB traces or vias to contend with, a 50% reduction in SMD
> spacing is obtained.
> 
> "Epoxy Pot" the top surface embedding all  the SMD's.
> 
> Flip over the substrate (now working from the bottom side) and release
> the tape and substrate from the potted assembly. Clean off any residual
> adhesive.
> 
> At this point, you should see only the exposed metal contacts of all the
> SMD's.
> 
> Using the modified Epson Artisan 50 printer (set head height to pass the
> 1/8" thick epoxy pot assembly depth) and print with special UV curable
> conductive ink (Metalon®)
> 
> UV cure (need to build a "homebrew" UV source for curing the conductive
> ink). The commercial version does it in 3 or 4 seconds.
> 
> Subsequent conductive traces (emulating the multi-layers of a
> conventional PCB) are first "masked out" by printing with a different
> inkjet of  NON-conducting ink at the conductive trace crossovers.
> 
> DONE!  : )
> 
> 
> 
> [Non-text portions of this message have been removed]
>

>
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@> wrote:
> >
> > I think you would have difficulty getting all the components lined up at exactly the same height and making reliable connections. It would be interesting to try but if I were trying to make something so complex I'd have a batch of boards made.
> >
>

>
> 
> 
> 
> Hi James!
> 
> "....difficulty getting all the components lined up at exactly the same height...." 
> 
> 
> You lost me here ... all the SMD's lay in flat down against the flat surface of the substrate, easily keeping all the SMD's at the same level.
> 
> --- In Homebrew_PCBs@yahoogroups.com, "richard.liberatoscioli" <richard.liberatoscioli@> wrote:
> >
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@> wrote:
> > >
> > > I think you would have difficulty getting all the components lined up at exactly the same height and making reliable connections. It would be interesting to try but if I were trying to make something so complex I'd have a batch of boards made.
> > >
> >
>

>
> I don't see the advantage of the flipping.
> 
> If you can print layers of conductive ink and non conductive ink then you
> can just make a multilayer pcb and place the components on top.  You can
> just make your final pads be all connected through the lower layers with the
> equivalent of blind filled vias.
> 
> I don't think the conductive ink ejects well but I'd be very curious to hear
> your results.
> 
> I've found some good UV curable inks but they're not cheap and they're not
> conductive.
> On Thu, May 20, 2010 at 2:59 PM, Richard
> <richard.liberatoscioli@...>wrote:
> 
> >
> >
> >
> >
> > Hi James!
> >
> > "....difficulty getting all the components lined up at exactly the same
> > height...."
> >
> > You lost me here ... all the SMD's lay in flat down against the flat
> > surface of the substrate, easily keeping all the SMD's at the same level.
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> > "richard.liberatoscioli" <richard.liberatoscioli@> wrote:
> > >
> > >
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> > "James" <jamesrsweet@> wrote:
> > > >
> > > > I think you would have difficulty getting all the components lined up
> > at exactly the same height and making reliable connections. It would be
> > interesting to try but if I were trying to make something so complex I'd
> > have a batch of boards made.
> > > >
> > >
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>

>
> Hi Henry!
> 
> Look here for the conductive inks:
> 
> http://www.novacentrix.com/
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Henry Liu <henryjliu@> wrote:
> >
> > I don't see the advantage of the flipping.
> > 
> > If you can print layers of conductive ink and non conductive ink then you
> > can just make a multilayer pcb and place the components on top.  You can
> > just make your final pads be all connected through the lower layers with the
> > equivalent of blind filled vias.
> > 
> > I don't think the conductive ink ejects well but I'd be very curious to hear
> > your results.
> > 
> > I've found some good UV curable inks but they're not cheap and they're not
> > conductive.
> > On Thu, May 20, 2010 at 2:59 PM, Richard
> > <richard.liberatoscioli@>wrote:
> > 
> > >
> > >
> > >
> > >
> > > Hi James!
> > >
> > > "....difficulty getting all the components lined up at exactly the same
> > > height...."
> > >
> > > You lost me here ... all the SMD's lay in flat down against the flat
> > > surface of the substrate, easily keeping all the SMD's at the same level.
> > >
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> > > "richard.liberatoscioli" <richard.liberatoscioli@> wrote:
> > > >
> > > >
> > > >
> > > > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> > > "James" <jamesrsweet@> wrote:
> > > > >
> > > > > I think you would have difficulty getting all the components lined up
> > > at exactly the same height and making reliable connections. It would be
> > > interesting to try but if I were trying to make something so complex I'd
> > > have a batch of boards made.
> > > > >
> > > >
> > >
> > >  
> > >
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

>
> Those machines look expensive.  Certainly a lot more expensive than sending
> it out to a pcb house.
> 
> If you are able to buy some ink and eject it out of a cheap epson printer,
> I'd be very interested!
> 
> On Thu, May 20, 2010 at 3:31 PM, Richard
> <richard.liberatoscioli@...>wrote:
> 
> >
> >
> > Hi Henry!
> >
> > Look here for the conductive inks:
> >
> > http://www.novacentrix.com/
> >
> 
> 
> [Non-text portions of this message have been removed]
>

>
> But can you eject the conductive ink with your $120 printer?  Have you tried
> anything exotic besides inkjet inks?  Will they even sell you the conductive
> ink in small samples?
> 
> Your project seems pretty doable using double sided technology.  If you're
> hurting on space, get BGA components and use 0201 components.
> 
> I pay like $2/board for professional assembly with 200 components.
> 
> On Thu, May 20, 2010 at 3:45 PM, Richard
> <richard.liberatoscioli@...>wrote:
> 
> >
> >
> >
> >
> > NOOOOOO! ... the mod printer is cheap! $ 120.00
> > Heres the mod I did:
> > http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/0/list
> >
> >
> > --- In Homebrew_PCBs@yahoogroups.com <Homebrew_PCBs%40yahoogroups.com>,
> > Henry Liu <henryjliu@> wrote:
> > >
> > > Those machines look expensive. Certainly a lot more expensive than
> > sending
> > > it out to a pcb house.
> > >
> > > If you are able to buy some ink and eject it out of a cheap epson
> > printer,
> > > I'd be very interested!
> > >
> > > On Thu, May 20, 2010 at 3:31 PM, Richard
> > > <richard.liberatoscioli@>wrote:
> >
> > >
> > > >
> > > >
> > > > Hi Henry!
> > > >
> > > > Look here for the conductive inks:
> > > >
> > > > http://www.novacentrix.com/
> > > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >  
> >
> 
> 
> [Non-text portions of this message have been removed]
>

>
> 
> Hello Homebrew Printed Circuit Group!
> 
> I have successfully modded my Epson Artisan 50 printer  Epson Printer
> Mod
> <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> this forum, want to quickly build working devices from all the many
> awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> 
> In my current project, I need to fabricate a "system-in-package" (SIP)
> module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> SMD's (resistors, capacitors, inductors, x-tal, etc).
> 
> This project requires very small SMD's and a very small and dense
> multi-layer PCB  with micro vias for fabrication.
> 
> This project well exceeds my existing "Homebrew" equipment capability to
> fabricate this module.
> 
> In assessing the demands for the size and scope of this project (for a
> "homebrew" solution) the "show stopper" was all in the  fabrication of
> the PCB itself.
> 
> Here I began my quest for a different "homebrew" solution.
> 
> Could I build this module without the complex multi-layer PCB?
> 
> Could I interconnect all SMD's (IC's and discrete's) without soldering?
> 
> 
> 
> Concept proposal:
> 
> Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> a conventional PCB.
> 
> Apply double sided releasable 3M "micro adhesive" tape covering the top
> surface of the substrate.
> 
> "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> with no PCB traces or vias to contend with, a 50% reduction in SMD
> spacing is obtained.
> 
> "Epoxy Pot" the top surface embedding all  the SMD's.
> 
> Flip over the substrate (now working from the bottom side) and release
> the tape and substrate from the potted assembly. Clean off any residual
> adhesive.
> 
> At this point, you should see only the exposed metal contacts of all the
> SMD's.
> 
> Using the modified Epson Artisan 50 printer (set head height to pass the
> 1/8" thick epoxy pot assembly depth) and print with special UV curable
> conductive ink (Metalon®)
> 
> UV cure (need to build a "homebrew" UV source for curing the conductive
> ink). The commercial version does it in 3 or 4 seconds.
> 
> Subsequent conductive traces (emulating the multi-layers of a
> conventional PCB) are first "masked out" by printing with a different
> inkjet of  NON-conducting ink at the conductive trace crossovers.
> 
> DONE!  : )
> 
> 
> 
> [Non-text portions of this message have been removed]
>

>
> 
> Hello Homebrew Printed Circuit Group!
> 
> I have successfully modded my Epson Artisan 50 printer  Epson Printer
> Mod
> <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> this forum, want to quickly build working devices from all the many
> awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> 
> In my current project, I need to fabricate a "system-in-package" (SIP)
> module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> SMD's (resistors, capacitors, inductors, x-tal, etc).
> 
> This project requires very small SMD's and a very small and dense
> multi-layer PCB  with micro vias for fabrication.
> 
> This project well exceeds my existing "Homebrew" equipment capability to
> fabricate this module.
> 
> In assessing the demands for the size and scope of this project (for a
> "homebrew" solution) the "show stopper" was all in the  fabrication of
> the PCB itself.
> 
> Here I began my quest for a different "homebrew" solution.
> 
> Could I build this module without the complex multi-layer PCB?
> 
> Could I interconnect all SMD's (IC's and discrete's) without soldering?
> 
> 
> 
> Concept proposal:
> 
> Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> a conventional PCB.
> 
> Apply double sided releasable 3M "micro adhesive" tape covering the top
> surface of the substrate.
> 
> "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> with no PCB traces or vias to contend with, a 50% reduction in SMD
> spacing is obtained.
> 
> "Epoxy Pot" the top surface embedding all  the SMD's.
> 
> Flip over the substrate (now working from the bottom side) and release
> the tape and substrate from the potted assembly. Clean off any residual
> adhesive.
> 
> At this point, you should see only the exposed metal contacts of all the
> SMD's.
> 
> Using the modified Epson Artisan 50 printer (set head height to pass the
> 1/8" thick epoxy pot assembly depth) and print with special UV curable
> conductive ink (Metalon®)
> 
> UV cure (need to build a "homebrew" UV source for curing the conductive
> ink). The commercial version does it in 3 or 4 seconds.
> 
> Subsequent conductive traces (emulating the multi-layers of a
> conventional PCB) are first "masked out" by printing with a different
> inkjet of  NON-conducting ink at the conductive trace crossovers.
> 
> DONE!  : )
> 
> 
> 
> [Non-text portions of this message have been removed]
>

>
> 
> 
> 
> 
> ..... an example of the conductive traces "reduction" ratio:
> 
> 64 pin leadless QFN RFID GEN2 UHF Reader IC with all required SMDs connected (res,caps,inductors,x-tal,etc.)
> 
> Conventional multi-layer "PCB"  verses "Flip n' Print"
> 
> 16 traces reduced to  4
>  5 traces reduced to  2
>  5 traces reduced to  2
> 14 traces reduced to  3
>  5 traces reduced to  2
> 23 traces reduced to 10
>  7 traces reduced to  4
>  5 traces reduced to  2
>  6 traces reduced to  3
>  8 traces reduced to  3
>  5 traces reduced to  2
>  6 traces reduced to  3
>  5 traces reduced to  2
> 
> Totals:
> 110 traces reduced to 41
> 
> Instead of a 5 or 6 layer conventional "PCB" (1.5" by 3/4") only 2 or 3 "printed layers" are needed.
> 
> By placing the SMDs "end to end" and "side by side" in combinations, for these connections, you afford essentially a zero "resistive loss",zero "stray inductance and capacitance" and highly conductive soldered connections.
> 
> With the now greatly reduced physical length of the "inkjetted conductive traces"(most are only 1/8" to 1/16" long), the higher resistance of the conductive inks now becomes negligible.
> 
> In essence, this assembly method uses the SMDs themselves as the majorty of the "wire traces" required.
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > 
> > Hello Homebrew Printed Circuit Group!
> > 
> > I have successfully modded my Epson Artisan 50 printer  Epson Printer
> > Mod
> > <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> > 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> > this forum, want to quickly build working devices from all the many
> > awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> > 
> > In my current project, I need to fabricate a "system-in-package" (SIP)
> > module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> > chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> > SMD's (resistors, capacitors, inductors, x-tal, etc).
> > 
> > This project requires very small SMD's and a very small and dense
> > multi-layer PCB  with micro vias for fabrication.
> > 
> > This project well exceeds my existing "Homebrew" equipment capability to
> > fabricate this module.
> > 
> > In assessing the demands for the size and scope of this project (for a
> > "homebrew" solution) the "show stopper" was all in the  fabrication of
> > the PCB itself.
> > 
> > Here I began my quest for a different "homebrew" solution.
> > 
> > Could I build this module without the complex multi-layer PCB?
> > 
> > Could I interconnect all SMD's (IC's and discrete's) without soldering?
> > 
> > 
> > 
> > Concept proposal:
> > 
> > Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> > a conventional PCB.
> > 
> > Apply double sided releasable 3M "micro adhesive" tape covering the top
> > surface of the substrate.
> > 
> > "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> > with no PCB traces or vias to contend with, a 50% reduction in SMD
> > spacing is obtained.
> > 
> > "Epoxy Pot" the top surface embedding all  the SMD's.
> > 
> > Flip over the substrate (now working from the bottom side) and release
> > the tape and substrate from the potted assembly. Clean off any residual
> > adhesive.
> > 
> > At this point, you should see only the exposed metal contacts of all the
> > SMD's.
> > 
> > Using the modified Epson Artisan 50 printer (set head height to pass the
> > 1/8" thick epoxy pot assembly depth) and print with special UV curable
> > conductive ink (Metalon®)
> > 
> > UV cure (need to build a "homebrew" UV source for curing the conductive
> > ink). The commercial version does it in 3 or 4 seconds.
> > 
> > Subsequent conductive traces (emulating the multi-layers of a
> > conventional PCB) are first "masked out" by printing with a different
> > inkjet of  NON-conducting ink at the conductive trace crossovers.
> > 
> > DONE!  : )
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

>
> So you're saying that you're soldering SMD devices directly to one another
> on the board when possible, instead of running traces?
> 
> -Andrew
> 
> 
> [Non-text portions of this message have been removed]
>

>
> 
> 
> 
> Project update:
> 
> In my modified Epson Artisan 50:
> http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/166497487/pic/list
> 
> I added a very simple 15 minute mod to allow the print head to pass my experimental "Flip n' Print" module.
> 
> The mod is simply to remove the two existing print head adjustment cams and permanently raise both ends of the print head "guide bar" to their maximum vertical heights. I used heavy gauge magnet wire to do this. DONE!
> 
> The printer now expects anything I want to print is 1/4" thick. 
> 
> This thickness is ideal for my project even allowing for the 1/4" mini-pin header for connections to the outside world (USB,I/O,Battery,etc).
> 
> I will now be fabricating the "potting molds" representing the board size of my project (can be of any size from 3/4" by 3/4" up to 7" by 10"). I will be using 1/4" thick Dupont "Corian" for its easy to machine router and cut very precisely. Not only does the Corian serve as the potting mold, but also serves as the carrier transport for feeding the potted SMDs through the printer. No matter what size "potted board" your making, the carrier transport dimensions will always be 8 1/2" by 11"(for stable printer feeding through the printer). The "potting mold" templates are 100% reusable.
> 
> 
> 
> Other stuff:
> 
> As I pointed out before, by not having PCB traces and vias on the same surface as your SMDs, an over 50% reduction in "board size" is afforded. Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> 
> For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> 
> This normally would take 16 PCB tracks just to do this. By joining the SMDs "physically", soldered end to end without wires, from the top surface, I have now reduced my "printed wiring" down to just 4 connections. Similar printed wiring reductions are reflected throughout the entire assembly. Basically, your eliminating approximately 50 to 80% of the total "printed wiring" required!! 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > 
> > Hello Homebrew Printed Circuit Group!
> > 
> > I have successfully modded my Epson Artisan 50 printer  Epson Printer
> > Mod
> > <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> > 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> > this forum, want to quickly build working devices from all the many
> > awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> > 
> > In my current project, I need to fabricate a "system-in-package" (SIP)
> > module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> > chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> > SMD's (resistors, capacitors, inductors, x-tal, etc).
> > 
> > This project requires very small SMD's and a very small and dense
> > multi-layer PCB  with micro vias for fabrication.
> > 
> > This project well exceeds my existing "Homebrew" equipment capability to
> > fabricate this module.
> > 
> > In assessing the demands for the size and scope of this project (for a
> > "homebrew" solution) the "show stopper" was all in the  fabrication of
> > the PCB itself.
> > 
> > Here I began my quest for a different "homebrew" solution.
> > 
> > Could I build this module without the complex multi-layer PCB?
> > 
> > Could I interconnect all SMD's (IC's and discrete's) without soldering?
> > 
> > 
> > 
> > Concept proposal:
> > 
> > Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> > a conventional PCB.
> > 
> > Apply double sided releasable 3M "micro adhesive" tape covering the top
> > surface of the substrate.
> > 
> > "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> > with no PCB traces or vias to contend with, a 50% reduction in SMD
> > spacing is obtained.
> > 
> > "Epoxy Pot" the top surface embedding all  the SMD's.
> > 
> > Flip over the substrate (now working from the bottom side) and release
> > the tape and substrate from the potted assembly. Clean off any residual
> > adhesive.
> > 
> > At this point, you should see only the exposed metal contacts of all the
> > SMD's.
> > 
> > Using the modified Epson Artisan 50 printer (set head height to pass the
> > 1/8" thick epoxy pot assembly depth) and print with special UV curable
> > conductive ink (Metalon®)
> > 
> > UV cure (need to build a "homebrew" UV source for curing the conductive
> > ink). The commercial version does it in 3 or 4 seconds.
> > 
> > Subsequent conductive traces (emulating the multi-layers of a
> > conventional PCB) are first "masked out" by printing with a different
> > inkjet of  NON-conducting ink at the conductive trace crossovers.
> > 
> > DONE!  : )
> > 
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

>
> NOTE:
> 
> I have the special metal CD insert for making 2.5" by 3.5" conventional circuit boards made by Full Spectrum Engineering.
> 
> You can read about it here:
> http://www.fullspectrumengineering.com/pcbinkjet.html
> 
> Its yours for the asking (FREE) ....just drop me an e-mail or Yahoo IM
> 
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > 
> > 
> > 
> > 
> > ..... an example of the conductive traces "reduction" ratio:
> > 
> > 64 pin leadless QFN RFID GEN2 UHF Reader IC with all required SMDs connected (res,caps,inductors,x-tal,etc.)
> > 
> > Conventional multi-layer "PCB"  verses "Flip n' Print"
> > 
> > 16 traces reduced to  4
> >  5 traces reduced to  2
> >  5 traces reduced to  2
> > 14 traces reduced to  3
> >  5 traces reduced to  2
> > 23 traces reduced to 10
> >  7 traces reduced to  4
> >  5 traces reduced to  2
> >  6 traces reduced to  3
> >  8 traces reduced to  3
> >  5 traces reduced to  2
> >  6 traces reduced to  3
> >  5 traces reduced to  2
> > 
> > Totals:
> > 110 traces reduced to 41
> > 
> > Instead of a 5 or 6 layer conventional "PCB" (1.5" by 3/4") only 2 or 3 "printed layers" are needed.
> > 
> > By placing the SMDs "end to end" and "side by side" in combinations, for these connections, you afford essentially a zero "resistive loss",zero "stray inductance and capacitance" and highly conductive soldered connections.
> > 
> > With the now greatly reduced physical length of the "inkjetted conductive traces"(most are only 1/8" to 1/16" long), the higher resistance of the conductive inks now becomes negligible.
> > 
> > In essence, this assembly method uses the SMDs themselves as the majorty of the "wire traces" required.
> > 
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >
> > > 
> > > Hello Homebrew Printed Circuit Group!
> > > 
> > > I have successfully modded my Epson Artisan 50 printer  Epson Printer
> > > Mod
> > > <http://groups.yahoo.com/group/Inkjet_PCB_Construction/photos/album/1664\
> > > 97487/pic/list>   to make PCB boards.  I did this, as I'm sure as all in
> > > this forum, want to quickly build working devices from all the many
> > > awesome microchips out there (ie: MCU, RFID,WIFI,GSP, etc.)
> > > 
> > > In my current project, I need to fabricate a "system-in-package" (SIP)
> > > module  containing an RFID reader chip (QFN), MCU chip and  WIFI
> > > chip(QFN) on two PCB's (1 1/4" x 3/4") including the required discrete
> > > SMD's (resistors, capacitors, inductors, x-tal, etc).
> > > 
> > > This project requires very small SMD's and a very small and dense
> > > multi-layer PCB  with micro vias for fabrication.
> > > 
> > > This project well exceeds my existing "Homebrew" equipment capability to
> > > fabricate this module.
> > > 
> > > In assessing the demands for the size and scope of this project (for a
> > > "homebrew" solution) the "show stopper" was all in the  fabrication of
> > > the PCB itself.
> > > 
> > > Here I began my quest for a different "homebrew" solution.
> > > 
> > > Could I build this module without the complex multi-layer PCB?
> > > 
> > > Could I interconnect all SMD's (IC's and discrete's) without soldering?
> > > 
> > > 
> > > 
> > > Concept proposal:
> > > 
> > > Start with a blank substrate (metal, glass, FR4,ceramic,etc) in place of
> > > a conventional PCB.
> > > 
> > > Apply double sided releasable 3M "micro adhesive" tape covering the top
> > > surface of the substrate.
> > > 
> > > "Pick and Place" all SMD's onto the top surface of the substrate. Note:
> > > with no PCB traces or vias to contend with, a 50% reduction in SMD
> > > spacing is obtained.
> > > 
> > > "Epoxy Pot" the top surface embedding all  the SMD's.
> > > 
> > > Flip over the substrate (now working from the bottom side) and release
> > > the tape and substrate from the potted assembly. Clean off any residual
> > > adhesive.
> > > 
> > > At this point, you should see only the exposed metal contacts of all the
> > > SMD's.
> > > 
> > > Using the modified Epson Artisan 50 printer (set head height to pass the
> > > 1/8" thick epoxy pot assembly depth) and print with special UV curable
> > > conductive ink (Metalon®)
> > > 
> > > UV cure (need to build a "homebrew" UV source for curing the conductive
> > > ink). The commercial version does it in 3 or 4 seconds.
> > > 
> > > Subsequent conductive traces (emulating the multi-layers of a
> > > conventional PCB) are first "masked out" by printing with a different
> > > inkjet of  NON-conducting ink at the conductive trace crossovers.
> > > 
> > > DONE!  : )
> > > 
> > > 
> > > 
> > > [Non-text portions of this message have been removed]
> > >
> >
>

>
> How often can this be practical? It seems to me that the vast majority of
> signals would not happen to align with the physical pin you needed in order
> to attach components side by side. You'd need to space them out and put
> small traces.
> 
> I have seen some clever IC configurations along these lines, though - I've
> once seen on a production board, SMT memory ICs literally stacked atop one
> another, all the top pins soldered directly to the bottom pins, with just
> the chip-enable and write-enable signals broken out independently.
> 
> -Andrew
> 
> On Tue, May 25, 2010 at 10:28 AM, Richard
> <richard.liberatoscioli@...>wrote:
> 
> >
> >
> > .........Yes!
> >
> > Any RCL electronically grouped is "physically grouped" into a very tight
> > formation during the "pick and place"
> >
> 
> 
> [Non-text portions of this message have been removed]
>

>
> How often can this be practical? It seems to me that the vast majority of
> signals would not happen to align with the physical pin you needed in order
> to attach components side by side. You'd need to space them out and put
> small traces.
> 
> I have seen some clever IC configurations along these lines, though - I've
> once seen on a production board, SMT memory ICs literally stacked atop one
> another, all the top pins soldered directly to the bottom pins, with just
> the chip-enable and write-enable signals broken out independently.
> 
> -Andrew
> 
> On Tue, May 25, 2010 at 10:28 AM, Richard
> <richard.liberatoscioli@...>wrote:
> 
> >
> >
> > .........Yes!
> >
> > Any RCL electronically grouped is "physically grouped" into a very tight
> > formation during the "pick and place"
> >
> 
> 
> [Non-text portions of this message have been removed]
>

>
> Hi Andrew!
> 
> I'm not sure exactly what your saying.
> 
> First, did this make sense to you?:
> http://tech.groups.yahoo.com/group/Homebrew_PCBs/message/25979
> 
> Basically, what I'm doing is making micro "hybrids" out of the top LCR circuitry before I commit them to bottom layer routing.
> 
> IE: a top layer 16 point(connection)circuit then becomes only 4 points of bottom layer(connections) Your PCB placement and routing software now sees the this "hybrid lump" as only 4 points of connections.
> 
> In other words, this method is not just one routing algorithm, but divided into two, a separate "top layer optimization" and a separate "bottom layer optimization". 
> 
> Also, Inkjetting the "muti-layer bottom layers"(conductive and insulating) affords a unique optimization in routing in that you can now "spot mask" areas without masking the entire layer.
> 
> If you dont understand what I'm saying here, I can give you a link to my webmeeting for a audio/visual explanation of this.
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Andrew Villeneuve <andrewmv@> wrote:
> >
> > How often can this be practical? It seems to me that the vast majority of
> > signals would not happen to align with the physical pin you needed in order
> > to attach components side by side. You'd need to space them out and put
> > small traces.
> > 
> > I have seen some clever IC configurations along these lines, though - I've
> > once seen on a production board, SMT memory ICs literally stacked atop one
> > another, all the top pins soldered directly to the bottom pins, with just
> > the chip-enable and write-enable signals broken out independently.
> > 
> > -Andrew
> > 
> > On Tue, May 25, 2010 at 10:28 AM, Richard
> > <richard.liberatoscioli@>wrote:
> > 
> > >
> > >
> > > .........Yes!
> > >
> > > Any RCL electronically grouped is "physically grouped" into a very tight
> > > formation during the "pick and place"
> > >
> > 
> > 
> > [Non-text portions of this message have been removed]
> >
>

>
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
>  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > 
> > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > 
> > > This normally would take 16 PCB tracks just to do this. By 
> > joining the SMDs "physically", soldered end to end without 
> > wires, from the top surface, I have now reduced my "printed 
> > wiring" down to just 4 connections. Similar printed wiring
> > reductions are reflected throughout the entire assembly. 
> 
> Wow - very creative effort, indeed.
> How do you ensure the accuracy of the SMD placement on the tape?
>

>
> Hi gnuv!
> 
> On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component layout screen (lets say that's a 2.5"x3.5" finished module size) in the center of this substrate.
> 
> Apply double sided (releasable) "micro-adhesive" tape/film over your printed screen (its "micro thin" and "see through").
> 
> Apply SMDs with a vacuum assisted "pick and place" probe.
> 
> When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ potting mold (with the 2.5"x3.5" square hole in the middle).
> 
> Epoxy Pot to top of mold. When cured, release potting mold from substrate, potting mold is then flipped over, and run through the modified printer for conductive and insulative inkjeting.
> 
> 
>    
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "gnuvvekaavaali" <gnuvvekaavaali@> wrote:
> >
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > > 
> > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > > 
> > > > This normally would take 16 PCB tracks just to do this. By 
> > > joining the SMDs "physically", soldered end to end without 
> > > wires, from the top surface, I have now reduced my "printed 
> > > wiring" down to just 4 connections. Similar printed wiring
> > > reductions are reflected throughout the entire assembly. 
> > 
> > Wow - very creative effort, indeed.
> > How do you ensure the accuracy of the SMD placement on the tape?
> >
>

>
> ...... screen printing "on top" of the "micro-adhesive: may be an even  better solution.
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > Hi gnuv!
> > 
> > On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component layout screen (lets say that's a 2.5"x3.5" finished module size) in the center of this substrate.
> > 
> > Apply double sided (releasable) "micro-adhesive" tape/film over your printed screen (its "micro thin" and "see through").
> > 
> > Apply SMDs with a vacuum assisted "pick and place" probe.
> > 
> > When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ potting mold (with the 2.5"x3.5" square hole in the middle).
> > 
> > Epoxy Pot to top of mold. When cured, release potting mold from substrate, potting mold is then flipped over, and run through the modified printer for conductive and insulative inkjeting.
> > 
> > 
> >    
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "gnuvvekaavaali" <gnuvvekaavaali@> wrote:
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > > > 
> > > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > > > 
> > > > > This normally would take 16 PCB tracks just to do this. By 
> > > > joining the SMDs "physically", soldered end to end without 
> > > > wires, from the top surface, I have now reduced my "printed 
> > > > wiring" down to just 4 connections. Similar printed wiring
> > > > reductions are reflected throughout the entire assembly. 
> > > 
> > > Wow - very creative effort, indeed.
> > > How do you ensure the accuracy of the SMD placement on the tape?
> > >
> >
>

>
> It may even be possible to print both the conductive and insulating layers at the same time as they are from separate inkjets.
> 
> This would cut the total "print/UV cure" time in halve!!
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > ...... screen printing "on top" of the "micro-adhesive: may be an even  better solution.
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >
> > > Hi gnuv!
> > > 
> > > On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component layout screen (lets say that's a 2.5"x3.5" finished module size) in the center of this substrate.
> > > 
> > > Apply double sided (releasable) "micro-adhesive" tape/film over your printed screen (its "micro thin" and "see through").
> > > 
> > > Apply SMDs with a vacuum assisted "pick and place" probe.
> > > 
> > > When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ potting mold (with the 2.5"x3.5" square hole in the middle).
> > > 
> > > Epoxy Pot to top of mold. When cured, release potting mold from substrate, potting mold is then flipped over, and run through the modified printer for conductive and insulative inkjeting.
> > > 
> > > 
> > >    
> > > 
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "gnuvvekaavaali" <gnuvvekaavaali@> wrote:
> > > >
> > > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > >  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > > > > 
> > > > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > > > > 
> > > > > > This normally would take 16 PCB tracks just to do this. By 
> > > > > joining the SMDs "physically", soldered end to end without 
> > > > > wires, from the top surface, I have now reduced my "printed 
> > > > > wiring" down to just 4 connections. Similar printed wiring
> > > > > reductions are reflected throughout the entire assembly. 
> > > > 
> > > > Wow - very creative effort, indeed.
> > > > How do you ensure the accuracy of the SMD placement on the tape?
> > > >
> > >
> >
>

>
> NOTE: The LAST thing you do is to release your completed epoxy potted module from the Corian@ "mold/carrier".
> 
> 
> Should this assembly process prove competent, fabrication of extremely dense, multi-chip modules could be completed and working in around 4 hours(provided parts in hand and cad ready).
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > It may even be possible to print both the conductive and insulating layers at the same time as they are from separate inkjets.
> > 
> > This would cut the total "print/UV cure" time in halve!!
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >
> > > ...... screen printing "on top" of the "micro-adhesive: may be an even  better solution.
> > > 
> > > 
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > >
> > > > Hi gnuv!
> > > > 
> > > > On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component layout screen (lets say that's a 2.5"x3.5" finished module size) in the center of this substrate.
> > > > 
> > > > Apply double sided (releasable) "micro-adhesive" tape/film over your printed screen (its "micro thin" and "see through").
> > > > 
> > > > Apply SMDs with a vacuum assisted "pick and place" probe.
> > > > 
> > > > When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ potting mold (with the 2.5"x3.5" square hole in the middle).
> > > > 
> > > > Epoxy Pot to top of mold. When cured, release potting mold from substrate, potting mold is then flipped over, and run through the modified printer for conductive and insulative inkjeting.
> > > > 
> > > > 
> > > >    
> > > > 
> > > > 
> > > > --- In Homebrew_PCBs@yahoogroups.com, "gnuvvekaavaali" <gnuvvekaavaali@> wrote:
> > > > >
> > > > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > > >  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > > > > > 
> > > > > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > > > > > 
> > > > > > > This normally would take 16 PCB tracks just to do this. By 
> > > > > > joining the SMDs "physically", soldered end to end without 
> > > > > > wires, from the top surface, I have now reduced my "printed 
> > > > > > wiring" down to just 4 connections. Similar printed wiring
> > > > > > reductions are reflected throughout the entire assembly. 
> > > > > 
> > > > > Wow - very creative effort, indeed.
> > > > > How do you ensure the accuracy of the SMD placement on the tape?
> > > > >
> > > >
> > >
> >
>

>
> Design considerations:
> 
> As this assembly process is targeted to the fabrication of very low powered 3/5volt microchips and their supporting SMDs, there are instances where in the final output stage, higher current carrying capacity wiring is required. 
> 
> The wiring (ultrasonic die bonding wires) used "inside" the microchip address this issue by doubling or tripling the bonding wires to the same connection.
> 
> The simple addition of "solderable" insulated magnet wire for these higher current conductive paths are resolved (this is a very easy and minimal "manual" wiring requirement).
> 
> 
> In other RF microchips (ie: Bluetooth,WIFI,GSM,etc) "coplanar printed" transmission paths could be fabricated.
> 
> 
> 
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > NOTE: The LAST thing you do is to release your completed epoxy potted module from the Corian@ "mold/carrier".
> > 
> > 
> > Should this assembly process prove competent, fabrication of extremely dense, multi-chip modules could be completed and working in around 4 hours(provided parts in hand and cad ready).
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >
> > > It may even be possible to print both the conductive and insulating layers at the same time as they are from separate inkjets.
> > > 
> > > This would cut the total "print/UV cure" time in halve!!
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > >
> > > > ...... screen printing "on top" of the "micro-adhesive: may be an even  better solution.
> > > > 
> > > > 
> > > > 
> > > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > > >
> > > > > Hi gnuv!
> > > > > 
> > > > > On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component layout screen (lets say that's a 2.5"x3.5" finished module size) in the center of this substrate.
> > > > > 
> > > > > Apply double sided (releasable) "micro-adhesive" tape/film over your printed screen (its "micro thin" and "see through").
> > > > > 
> > > > > Apply SMDs with a vacuum assisted "pick and place" probe.
> > > > > 
> > > > > When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ potting mold (with the 2.5"x3.5" square hole in the middle).
> > > > > 
> > > > > Epoxy Pot to top of mold. When cured, release potting mold from substrate, potting mold is then flipped over, and run through the modified printer for conductive and insulative inkjeting.
> > > > > 
> > > > > 
> > > > >    
> > > > > 
> > > > > 
> > > > > --- In Homebrew_PCBs@yahoogroups.com, "gnuvvekaavaali" <gnuvvekaavaali@> wrote:
> > > > > >
> > > > > > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > > > > >  Something else I realized tonight, since the SMDs are "picked and placed" onto the "micro adhesive only"(no soldering) the SMDs can be placed  "end to end" or "side to side" depending on the design of your schematic. 
> > > > > > > > 
> > > > > > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, each leg going to two capacitors, then all caps go to vdd-. 
> > > > > > > > 
> > > > > > > > This normally would take 16 PCB tracks just to do this. By 
> > > > > > > joining the SMDs "physically", soldered end to end without 
> > > > > > > wires, from the top surface, I have now reduced my "printed 
> > > > > > > wiring" down to just 4 connections. Similar printed wiring
> > > > > > > reductions are reflected throughout the entire assembly. 
> > > > > > 
> > > > > > Wow - very creative effort, indeed.
> > > > > > How do you ensure the accuracy of the SMD placement on the tape?
> > > > > >
> > > > >
> > > >
> > >
> >
>

>
> Hi gnuv!
>
> On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component 
> layout screen (lets say that's a 2.5"x3.5" finished module size) in 
> the center of this substrate.
>
> Apply double sided (releasable) "micro-adhesive" tape/film over your 
> printed screen (its "micro thin" and "see through").
>
> Apply SMDs with a vacuum assisted "pick and place" probe.
>
> When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ 
> potting mold (with the 2.5"x3.5" square hole in the middle).
>
> Epoxy Pot to top of mold. When cured, release potting mold from 
> substrate, potting mold is then flipped over, and run through the 
> modified printer for conductive and insulative inkjeting.
>
> --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "gnuvvekaavaali" 
> <gnuvvekaavaali@...> wrote:
> >
> > --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "Richard" 
> <richard.liberatoscioli@> wrote:
> > Something else I realized tonight, since the SMDs are "picked and 
> placed" onto the "micro adhesive only"(no soldering) the SMDs can be 
> placed "end to end" or "side to side" depending on the design of your 
> schematic.
> > > >
> > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, 
> each leg going to two capacitors, then all caps go to vdd-.
> > > >
> > > > This normally would take 16 PCB tracks just to do this. By
> > > joining the SMDs "physically", soldered end to end without
> > > wires, from the top surface, I have now reduced my "printed
> > > wiring" down to just 4 connections. Similar printed wiring
> > > reductions are reflected throughout the entire assembly.
> >
> > Wow - very creative effort, indeed.
> > How do you ensure the accuracy of the SMD placement on the tape?
> >
>
>

>
> Richard,
> I am following the thread. because I like the creative 
> approach.Regarding accurate placement: Why don't you just place the 
> components arbitrarily and after potting and peeling of the tape you 
> scan the side with the exposed pins. With a piece of software (to be 
> written) the user then can interactively identify the components on the 
> image. With this information and the schematic the software has all the 
> information to do the rest, including printing.
> Although I can see a few problems with the general approach I think it's 
> worth following.
> Derk
> 
> 
> Richard wrote:
> >
> > Hi gnuv!
> >
> > On a blank 8.5"x11"x1/4" Corian@ substrate, print out your component 
> > layout screen (lets say that's a 2.5"x3.5" finished module size) in 
> > the center of this substrate.
> >
> > Apply double sided (releasable) "micro-adhesive" tape/film over your 
> > printed screen (its "micro thin" and "see through").
> >
> > Apply SMDs with a vacuum assisted "pick and place" probe.
> >
> > When finished, stack on top your substrate the 8.5"x11"x1/4" Corian@ 
> > potting mold (with the 2.5"x3.5" square hole in the middle).
> >
> > Epoxy Pot to top of mold. When cured, release potting mold from 
> > substrate, potting mold is then flipped over, and run through the 
> > modified printer for conductive and insulative inkjeting.
> >
> > --- In Homebrew_PCBs@yahoogroups.com 
> > <mailto:Homebrew_PCBs%40yahoogroups.com>, "gnuvvekaavaali" 
> > <gnuvvekaavaali@> wrote:
> > >
> > > --- In Homebrew_PCBs@yahoogroups.com 
> > <mailto:Homebrew_PCBs%40yahoogroups.com>, "Richard" 
> > <richard.liberatoscioli@> wrote:
> > > Something else I realized tonight, since the SMDs are "picked and 
> > placed" onto the "micro adhesive only"(no soldering) the SMDs can be 
> > placed "end to end" or "side to side" depending on the design of your 
> > schematic.
> > > > >
> > > > > For instance, 3 legs from my 64 pin QFN IC go to 6 capacitors, 
> > each leg going to two capacitors, then all caps go to vdd-.
> > > > >
> > > > > This normally would take 16 PCB tracks just to do this. By
> > > > joining the SMDs "physically", soldered end to end without
> > > > wires, from the top surface, I have now reduced my "printed
> > > > wiring" down to just 4 connections. Similar printed wiring
> > > > reductions are reflected throughout the entire assembly.
> > >
> > > Wow - very creative effort, indeed.
> > > How do you ensure the accuracy of the SMD placement on the tape?
> > >
> >
> >
>

>
> I'll respond briefly on this in hopes I'll get to better understand 
> the merits of your suggestions.
>
> In prima fasia, this would be a complete disaster. Placing the SMDs in 
> a "random" fashion, would seriously violate essential physical and 
> electronic associations that the components function provides.
>
> Example: With the very high speed microchips we use today, very heavy 
> use of decoupling and bypass capacitors must be used and must present 
> themselves IMMEDIATELY (asigned placement) on the IC pins they afford 
> their function to.
>
> "Random placement" of these components would folly at best.
>
> --- In Homebrew_PCBs@yahoogroups.com 
> <mailto:Homebrew_PCBs%40yahoogroups.com>, Derk Steggewentz <derks@...> 
> wrote:
> >
> > Richard,
> > I am following the thread. because I like the creative
> > approach.Regarding accurate placement: Why don't you just place the
> > components arbitrarily and after potting and peeling of the tape you
> > scan the side with the exposed pins. With a piece of software (to be
> > written) the user then can interactively identify the components on the
> > image. With this information and the schematic the software has all the
> > information to do the rest, including printing.
> > Although I can see a few problems with the general approach I think 
> it's
> > worth following.
> > Derk
> >
> >
> > Richard wrote:
> > >
>

>
> Richard wrote:
> >  
> >
> > Hi Derk!
> >
> > ....mmmmmmmmmmmmm , well, first let me say that your thought process 
> > is so powerful, I will have to assume that I fatally missed something 
> > in your rational.
> >
> 
> I guess so. Maybe because my unfortunate use of the term 'arbitrary'. 
> Although with my suggestion you could position components arbitrarily 
> because software could be written to do the trace printing (component 
> locations are taken from the scan), it, of course, does most of the  
> time makes no sense electrically/physically, as you pointed out (This is 
> self explanatory and I implied it). So you should still do a well 
> thought out component layout, but manual placement does not need to be 
> as precise as you suggested (making a hardcopy of the layout, put the 
> transparent adhesive foil on it, using a vacuum tool etc etc..). That 
> should make it easier for quick prototyping in the home lab - wasn't 
> that you initial idea?? It also would avoid mistakes in the component 
> layout because the trace printing function gets its information from the 
> actual physical scan of the components in place.
> Hope that makes my point a little clearer
> 
> Now, talking about high speed components and capacitors - Besides trace 
> resistance, the dielectric properties of the insulating ink and it's 
> thickness, which I assume is rather thin (significantly thinner compared 
> to multilayer pcb's), will sure have effects like coupling and unwanted 
> filtering. Granted, this problem is known for PCBs as well, but it is 
> understood to a degree.
> 
> What's about heat build up in the epoxy pot?
> 
> Another disadvantage, although it probably only plays a role for more 
> complex circuits, is, considering you suggested this method for quick 
> prototyping,  the fact that it's going to be very difficult to access 
> the circuit for probing (even many component pins might not be 
> accessible anymore) and  replacing or adding components is absolute 
> impossible. For me, these are both things that are extremely important 
> in prototyping. As a matter of fact, that's the whole idea of a 
> prototype. Spice and breadboarding just don't give you the whole picture 
> with increasing frequencies. Wouldn't matter so much for a final 
> product, but with that I would go to some pcb manufacturer anyway.
> 
> The last point actually would pretty much rule this method out for me, 
> even if it would work. I just wouldn't see a place in my development cycle
> (design on paper, component selection, simulating w/ SPICE, 
> breadboarding if necessary and/or possible, prototyping, probing and 
> refining, finalizing).
> 
> I still like the idea though, maybe just as a thought experiment - or 
> maybe for some special cases I could see an application.
> 
> Just some thoughts, Derk
> 
> 
> 
> 
> 
> 
> 
> 
> >
> > I'll respond briefly on this in hopes I'll get to better understand 
> > the merits of your suggestions.
> >
> > In prima fasia, this would be a complete disaster. Placing the SMDs in 
> > a "random" fashion, would seriously violate essential physical and 
> > electronic associations that the components function provides.
> >
> > Example: With the very high speed microchips we use today, very heavy 
> > use of decoupling and bypass capacitors must be used and must present 
> > themselves IMMEDIATELY (asigned placement) on the IC pins they afford 
> > their function to.
> >
> > "Random placement" of these components would folly at best.
> >
> > --- In Homebrew_PCBs@yahoogroups.com 
> > <mailto:Homebrew_PCBs%40yahoogroups.com>, Derk Steggewentz <derks@> 
> > wrote:
> > >
> > > Richard,
> > > I am following the thread. because I like the creative
> > > approach.Regarding accurate placement: Why don't you just place the
> > > components arbitrarily and after potting and peeling of the tape you
> > > scan the side with the exposed pins. With a piece of software (to be
> > > written) the user then can interactively identify the components on the
> > > image. With this information and the schematic the software has all the
> > > information to do the rest, including printing.
> > > Although I can see a few problems with the general approach I think 
> > it's
> > > worth following.
> > > Derk
> > >
> > >
> > > Richard wrote:
> > > >
> >
>

>
> Richard wrote:
> >  
> >
> >
> > Excellent and very powerful PCB CAD software already
> > exists(KICAD,Eagle,etc.)for FREE! Do you really want to start your 
> > project with trying to first write your own routing software?? I don't 
> > think the "homebrewer" has on staff a seasoned team of code writers at 
> > their disposal : (
> >
> No, I don't want to reinvent and reimplement existing router apps. I am 
> thinking of using the scan to e.g  correct component placement in the 
> input file of the Router, using maybe a router produced Gerber and 
> slightly shifting components, modifying/extending Kicad  etc. etc. There 
> are many approaches thinkable and they don't seem insurmountable to me.
> 
> 
> 
> 
> > Well, yes it does! The CAD software un-forgivenly demands this. It 
> > expects what you place in its "virtual design board" to be absolutely 
> > representative of the real world "outside physical placement" of the 
> > actual components location. When I have you print the component layout 
> > screen to the substrate, the CAD software later makes reference to 
> > this fine placement when you flip the module upside down and now needs 
> > to print micro thin conductive traces. Think about a 128 pin QFN IC 
> > with lets say 50 0404 SMDs. Your SMDs better be right on the money!
> >
> That problem is exactly what I tried to solve with my suggestion. Did 
> you ever try to manually place something onto something adhesive? When I 
> do, it's usually always a tiny little bit off. And then there is no 
> pushing around anymore and cursing won't help either, as soon as  one 
> corner touches the adhesive surface, that's it. Well, I guess some 
> mechanical and optical (think parallax) help can be constructed. I'd 
> rather write some code, trying to take human failure out of the equation.
> 
> > In re of "probing" .... your wrong! All the SMDs remain 
> > 100%accessible, even the connections "inside" of the constructed 
> > "micro-hybrids". Yes, they are covered by the insulating mask, simply 
> > run your finished module through the printer again, this time printing 
> > the "inverted version" of the component screen. With a micro-sized 
> > drill or sharp needle point probe, slightly tag the surface to pass 
> > through to the conductive layer underneat
> >
> I like your idea of  'running your finished module through the printer 
> again, this time printing the "inverted version" of the component 
> screen'. Good thought. But I have difficulties to think of how that 
> would work in the real world. What is if there is a conductive layer in 
> between, e.g. a  ground plane, which I can imagine you want considering 
> all this tight spacing and possibilities of capacitive coupling etc? Or, 
> if no layer, what if a trace crosses just there and you are poking your 
> needle through possibly more then one of them? It doesn't seem practical.
> 
> >
> > That's very true! But think about it. Is the "homebrewer" equipped 
> > with special and very expensive "solder re-work stations" that allows 
> > changing out a 128 pin QFN or 0404 SMDs??? Your talking about ICs that 
> > cost on average $3 to $5 and descretes around 20 cents a piece.
> > Have you ever tried to "solder wick" out a defective IC before? 
> > Chances are you'll lift every "pad" right of the board!
> > My point is .... for the cost and time involved,if you have a 
> > defective module...PRINT OUT A NEW ONE!! In about 4 hours, your back 
> > up and running.
> >
> 
> Yes, I hand solder surface mount components quite frequently. And yes, I 
> have tried and succeeded to "solder wick" out a defective IC before, 
> more then once. O.k. not a 128 pin QFN, but regular SOPs etc.. The 
> majority of SMT components ain't 128 pin QFN's anyway. Regular solder 
> station and a fine tip is all you need. I want to be able to do that 
> with my prototypes where an IC  (your quote) 'cost on average $3 to $5'. 
> PRINT OUT A NEW ONE (your quote) and throwing away maybe 10 of the other 
> chips in the circuit worth $3 to $5 apiece does not sound like a great 
> option to me. 
> 
> 
> > Manufacturers today must commit their prototypes to the fabracation of 
> > "real" sized PCBs to even develop the circuitry through many ite
> > ations of the "true sized" PCBs.
> >
> Very true. But that's not what you are doing with your technique. Your 
> 'hybrid' is as far away from a a 'real' sized PCB as it gets.
> 
> The advantage of real prototype PCBs are also that I can put my finger 
> onto components or traces, introducing capacitance and changing circuit 
> behaviour, take a soldering iron and quickly add a cap, change an R etc 
> etc (with my cheap soldering iron), until i am ready for the next 
> iteration of the prototype pcb.That would possibly save substantially on 
> the number of iterations.  Each iteration with your technique, even the 
> smallest, requires a complete redo. I can change an R in a minute while 
> you have a 4 hr turn around.
> 
> Derk
>

>
> Hi Derk!
> 
> Thank-you for your added/expanded thoughts here.
> 
> In this most resent iteration, I do now hold with much more in what your presenting. I now have a much better understanding to your points of view.
> 
> This concept assembly proposal is certainly not the cure all for all situations. 
> 
> I venture in this concept to address the desire to "homebrew" the many mobile projects I have in mind using the absolutely awesome capabilities of these new generation microchips, but realizing the "micro size" nature of them threatens the affordability and capability of the "homebrewers" to fabracate them.
> 
> This is my quest.
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Derk Steggewentz <derks@> wrote:
> >
> > Richard wrote:
> > >  
> > >
> > >
> > > Excellent and very powerful PCB CAD software already
> > > exists(KICAD,Eagle,etc.)for FREE! Do you really want to start your 
> > > project with trying to first write your own routing software?? I don't 
> > > think the "homebrewer" has on staff a seasoned team of code writers at 
> > > their disposal : (
> > >
> > No, I don't want to reinvent and reimplement existing router apps. I am 
> > thinking of using the scan to e.g  correct component placement in the 
> > input file of the Router, using maybe a router produced Gerber and 
> > slightly shifting components, modifying/extending Kicad  etc. etc. There 
> > are many approaches thinkable and they don't seem insurmountable to me.
> > 
> > 
> > 
> > 
> > > Well, yes it does! The CAD software un-forgivenly demands this. It 
> > > expects what you place in its "virtual design board" to be absolutely 
> > > representative of the real world "outside physical placement" of the 
> > > actual components location. When I have you print the component layout 
> > > screen to the substrate, the CAD software later makes reference to 
> > > this fine placement when you flip the module upside down and now needs 
> > > to print micro thin conductive traces. Think about a 128 pin QFN IC 
> > > with lets say 50 0404 SMDs. Your SMDs better be right on the money!
> > >
> > That problem is exactly what I tried to solve with my suggestion. Did 
> > you ever try to manually place something onto something adhesive? When I 
> > do, it's usually always a tiny little bit off. And then there is no 
> > pushing around anymore and cursing won't help either, as soon as  one 
> > corner touches the adhesive surface, that's it. Well, I guess some 
> > mechanical and optical (think parallax) help can be constructed. I'd 
> > rather write some code, trying to take human failure out of the equation.
> > 
> > > In re of "probing" .... your wrong! All the SMDs remain 
> > > 100%accessible, even the connections "inside" of the constructed 
> > > "micro-hybrids". Yes, they are covered by the insulating mask, simply 
> > > run your finished module through the printer again, this time printing 
> > > the "inverted version" of the component screen. With a micro-sized 
> > > drill or sharp needle point probe, slightly tag the surface to pass 
> > > through to the conductive layer underneat
> > >
> > I like your idea of  'running your finished module through the printer 
> > again, this time printing the "inverted version" of the component 
> > screen'. Good thought. But I have difficulties to think of how that 
> > would work in the real world. What is if there is a conductive layer in 
> > between, e.g. a  ground plane, which I can imagine you want considering 
> > all this tight spacing and possibilities of capacitive coupling etc? Or, 
> > if no layer, what if a trace crosses just there and you are poking your 
> > needle through possibly more then one of them? It doesn't seem practical.
> > 
> > >
> > > That's very true! But think about it. Is the "homebrewer" equipped 
> > > with special and very expensive "solder re-work stations" that allows 
> > > changing out a 128 pin QFN or 0404 SMDs??? Your talking about ICs that 
> > > cost on average $3 to $5 and descretes around 20 cents a piece.
> > > Have you ever tried to "solder wick" out a defective IC before? 
> > > Chances are you'll lift every "pad" right of the board!
> > > My point is .... for the cost and time involved,if you have a 
> > > defective module...PRINT OUT A NEW ONE!! In about 4 hours, your back 
> > > up and running.
> > >
> > 
> > Yes, I hand solder surface mount components quite frequently. And yes, I 
> > have tried and succeeded to "solder wick" out a defective IC before, 
> > more then once. O.k. not a 128 pin QFN, but regular SOPs etc.. The 
> > majority of SMT components ain't 128 pin QFN's anyway. Regular solder 
> > station and a fine tip is all you need. I want to be able to do that 
> > with my prototypes where an IC  (your quote) 'cost on average $3 to $5'. 
> > PRINT OUT A NEW ONE (your quote) and throwing away maybe 10 of the other 
> > chips in the circuit worth $3 to $5 apiece does not sound like a great 
> > option to me. 
> > 
> > 
> > > Manufacturers today must commit their prototypes to the fabracation of 
> > > "real" sized PCBs to even develop the circuitry through many ite
> > > ations of the "true sized" PCBs.
> > >
> > Very true. But that's not what you are doing with your technique. Your 
> > 'hybrid' is as far away from a a 'real' sized PCB as it gets.
> > 
> > The advantage of real prototype PCBs are also that I can put my finger 
> > onto components or traces, introducing capacitance and changing circuit 
> > behaviour, take a soldering iron and quickly add a cap, change an R etc 
> > etc (with my cheap soldering iron), until i am ready for the next 
> > iteration of the prototype pcb.That would possibly save substantially on 
> > the number of iterations.  Each iteration with your technique, even the 
> > smallest, requires a complete redo. I can change an R in a minute while 
> > you have a 4 hr turn around.
> > 
> > Derk
> >
>

>
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> >
> > Hi Derk!
> > 
> > ....mmmmmmmmmmmmm , well, first let me say that your thought process is so powerful, I will have to assume that I fatally missed something in your rational.
> > 
> > I'll respond briefly on this in hopes I'll  get to better understand the merits of your suggestions.
> > 
> > In prima fasia, this would be a complete disaster. Placing the SMDs in a "random" fashion, would seriously violate essential physical and electronic associations that the components function provides.
> > 
> >
> 
> 
> I don't think he meant just randomly throwing them down wherever they land, but rather place them such that the layout makes sense, without worrying about the precise alignment of everything, then scan that and draw the traces for it. There are certain rules for the layout, but components need not be placed with extreme precision.
>

>
> Hi James!
> 
> Yes! .....  after narrowing down Derks process, it's really a brilliant idea!
> 
> I've tried at look see at this in KIKAD, if I could get the "scanned" jpeg into the software's design window to show up as an overylay.
> 
> There would be a need to have some "reference object" in the scanned jpeg so you could scale your design window against the scale of KIKAD. 
> 
> I'll continue to ponder this process for sure.
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "James" <jamesrsweet@> wrote:
> >
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "Richard" <richard.liberatoscioli@> wrote:
> > >
> > > Hi Derk!
> > > 
> > > ....mmmmmmmmmmmmm , well, first let me say that your thought process is so powerful, I will have to assume that I fatally missed something in your rational.
> > > 
> > > I'll respond briefly on this in hopes I'll  get to better understand the merits of your suggestions.
> > > 
> > > In prima fasia, this would be a complete disaster. Placing the SMDs in a "random" fashion, would seriously violate essential physical and electronic associations that the components function provides.
> > > 
> > >
> > 
> > 
> > I don't think he meant just randomly throwing them down wherever they land, but rather place them such that the layout makes sense, without worrying about the precise alignment of everything, then scan that and draw the traces for it. There are certain rules for the layout, but components need not be placed with extreme precision.
> >
>