Patrick,
I'm in the lucky position that I can get chemistry from ROHM&HAAS
through a local board house kind enough to give away small quantities
(ok, I have to pay for the really expensive stuff, but a lot less than
at other places). Unfortunately the local ROHM&HAAS supplier is not
willing to directly sell to me due to the way too small quantities I
would take (even if I buy their smallest containers, aparently this is
too much work for them for the money). Anyways, since I can get it
thorugh the board house I don't care too much about that aspect.
Do I asume correctly that your references to Brighner 'A', 'B', 'R' and
so on you refer to products from ROHM&HAAS? Is " Tin fluoborate" also a
product from there?
As for the film makeing, I'm using an Epson Stylus C62 ink jet printer.
Unfortunately THIS little print wonder (really, you can't compare this
with other regular inkjets) is no longer produced. However, I heard from
people in a german PCB forum that the Cannon Pixma 4500 is in the same
league and this one is still actively produced and sold. These printers
produce very high quality results when you print on overhead
transparencies from Avery/Zweckform (250x series). One must set the
driver to use "glossy quailty photopaper" (or similar). Such film is
very well suited to be used with photoresist. The only drawback here is
that if you print big areas in black, the amount of ink used will be
impressive. In fact, that's the reason why I think that the method you
presented of using dryfilm on the PCB during thru plating will probalby
be more expensive for me versus the way I do it now (cause in my case
most areas of the film don't have to contain ink), but again the process
seems intersting, and especially the fact of having a higher quality
finish with the tin plating is tempting. Do you also have a recipe to
make a lead free thin plating bath?
In order to position the film, I usually print diagonal 6mm diameter
rings (inner diameter is 3.1mm) outside of the PCB area (well, I always
make PCBs as a small pannel which surrounds the real PCB which is cut
out as the last step) and then I use a home made film puncher to
precisely punch 3mm holes. The extra 0.1mm then helps me to very very
precisely alling the film on the puncher using my eitght times
magnifying head googles. I also drill 3mm holes through the whole PCB
stack (in case of makeing multilayers) using a small CNC drill as one of
the very first steps of the PCB makeing process. Since the exposer unit
is also having holes in the glass at those positions, I can simply stick
the film over the laminated base material and then expose. This way I
get a precision good enough for the process. It's true though that one
must work very carefully here.
Your statement " The diazo film exist also from other fabricator, DUPONT
and an other in Zwitserland." Seems intersting to me. Could it be that
you meant "Switzerland"? If so, I would be interested to hear the name
of this firm.
Markus
tsescrl schrieb:
>
> Hello,
>
> Thanks for beer, here in Belgium we love beer...
>
> You pupose a transparent spray for paper, wy not.
>
> But, for photoresist, is necesary you expose with strong UV due to 20
> microns higth of the photoresist ==> is also necesary you have a very
> hard black film on pads and track normaly density 3 or 4.
>
> But in industy, we d'ont use the black and transparent film, this
> film is the original film come from a lazer photoplotter.
>
> We make a copy of the original film for 2 raison.
>
> 1, If we have a production problem ( foot on film, scratch...) we
> have a good original to make a new copy.
>
> But an other very important raison:
>
> With the black and transparent film, you d'ont see correctly to
> adjust your film and center the holes in the center of your pads.
>
> We make a copy on a diazo amber film.
>
> This film have an orange or amber transparent color on pads and
> tracks, he stop very strong the UV, and you can see the hole to
> adjust and register the pad in hole center.
>
> This film is so simple to make, this film is an autopositive process,
> exposition with UV from your exposur unit, and developpement in vapor
> amonia, the same for architechtural plant.
>
> We use A film from "ROHM&HAAS" type "ULTRAYIELD 200 or 300 or 310"
> The problem for you is to obtain smal quatity, only box with 100 film.
>
> But also the problem for you is to obtain a film have the correct
> dimmension, if you drill with a little CNC, you are correct with the
> coordinate "X" and "Y", bur your image have a deformation due to
> lazer cook.
>
> But, for little dimension PCB perhaps you d'ont see this deformation.
>
> I have a friend hi make a transparent on a inkjet printer, EPSON, and
> in A3, he have no deformation, this printer have 2 position scale for
> the 2 axes, and i am very impresioned with the precision if i see the
> difference of price of my photoploter and this little non expensive
> printer...
>
> After print on the transparent, we make a copy on diazofilm, and no
> problem to expose with UV on dry film.
>
> For dry film, we use "LAMINAR 5038" form "ROHM&HAAS"
>
> The diazo film exist also from other fabricator, DUPONT and an other
> in Zwitserland.
>
> Also with a friend, we make test with direct inkjet printing on the
> PCB plate after métalisation with special ink.
>
> He is a group on YAHOO, and different site with this techinque.
>
> http://blog.makezine.com/archive/2006/08/how_to_direct_to_pcb_ink_jet_
> <http://blog.makezine.com/archive/2006/08/how_to_direct_to_pcb_ink_jet_>
> r.html
>
> http://techref.massmind.org/techref/pcb/etch/directinkjetresist.htm
> <http://techref.massmind.org/techref/pcb/etch/directinkjetresist.htm>
>
> I have a big interest for this procedure for ptototype, because, no
> film, no copy, no dry film, no developement.
>
> For direct inkjet image for simple face and etch with Fe3cl, non
> problem, the problem is for make a registration if i drill before
> inkjet printing, we see also in the futur if the special ink is
> resistant in copper and tin-lead electolitic bath.
>
> We see, and make information to you in a few week.
>
> For chemical trouhg holes line, from 10 year ago, i have make mysef
> the bath, but new procces are come on the market, and now we use a
> complete chemical line from "ROHM&HAAS" this proces is the "CRIMSON
> LINE" before, the name of this company is "SHIPLEY" he have good
> representation in europe and in USA.
> But hi exist also an other system from "MACK DERMIT" this is
> the "BLACK HOLE".
> >From Bungard, i d'ont now the origin of the chemical, Bungard is not
> a fabricator of chemical, perhaps he make little bottle conditionment
> for you, i think this is an good idea for your market.
>
> For copper and Tin or Tin-lead electro deposition, i make myself,
> this 2 bath are very stable, 8 or 10 years time life, no problem.
>
> Just i buy the brigtner to "ROHM&HAAS" the brigtner is so difficult
> to make, this is a special preparation of "PEPTONE", hi come of
> muscle of animal, yes yes.
>
> Other:
>
> After etching with the process i have decribe, your Tin or tin-lead
> is MAT, to obtain glossy, is necesary to make a fusion with higt
> température oil, and heat gun, not automobile oil...but special oil,
> and this oil is clean after with watter and little of "DEFT" or "PER"
> or other liquid spons, the same use your wife to clean after
> heat...this oil is watter soluble.
>
> To make start up solution for copper electro plating:
> For 100 litres:
>
> Demineralised watter : 54.00 liter
> Sulfurik acid : 11.00 liter
> Liquid copper sulfate: 29.00 liter
> Brigtner type M : 4.00 litre
> Brigtner type B : 0.25 litre
> Brigtner type L : 0.25 litre
> Ad the rest with demineralised watter.
> Attention with Sulfiric acid, only acid in watter and not inverse
> watter in acid = explosion, very very dangerous!!!use glove and brill.
> Add Sulfiric acid very very slowly, because you have big temperature
> elevation
> Liquid copper sulfate is a 68.7 gr/litre special electro.
>
> To make Tin-Lead start up solution electro plating:
> For 100 litres:
>
> Demineralised watter : 50.00 litres
> Fluoborik acid at 50% : 30.00 litres
> Borick acid : 1.5 Kg disolved in warm watter before
> Tin fluoborate at 50% : 6.75 litres
> Lead fluoborate at 50% : 2.25 litres
> Brigtner A : 1.75 litre
> Brigtner B : 1.75 litre
> Brigtner R : 1.00 litre
> Complete with demineralised watter.
> Put a back with 5 kilos of borick acid in a coin of thank permanently
>
> Good amusement
>
> Patrick
>
> --- In Homebrew_PCBs@yahoogroups.com
> <mailto:Homebrew_PCBs%40yahoogroups.com>, "dandumit" <dandumit@...> wrote:
> >
> > Patrick and Markus, THANK YOU !
> > I am following this group for more than one year but your revealings
> > shared here it is the first professional information that I have
> > found it here. Are indeed some ingenious hacks in this group too but
> > you two deserve a prize. I would like you to have some beers on my
> > account or a bottle of wine.
> >
> > Continuing on trough hole plating :
> > 1. Patrick - your solution it is very ingenious to have more simple
> > holes plated and ready etched. I have understood that in this
> process
> > you use the film positive (tracks and pads are black) and the
> > photoresist negative. This spray :
> > http://www.crceurope.com/csp/web/ProdDisp.csp?
> <http://www.crceurope.com/csp/web/ProdDisp.csp?>
> lng=3&country=ALL&product=TRANSPARANT%2021&business=ELECTRONIC
> > Makes a regular printer paper transparent to UV light. Could you
> > please tell us what could be used to replace it ? (of course a
> cheaper
> > version). This way a regular laser print could be used as a film !
> >
> > Patrick could you also give us some recipes some of baths ? Did you
> > prepared at your work or you have bought them from a specialized
> company ?
> >
> > 2. Suske - could you share with us from where do you plan to buy the
> > chemicals for baths ?
> >
> > Kind Regards,
> > Daniel
> >
>
>