Homebrew PCBs

I am going to trying using James Mitchell's plated-thru hole method this
week and I wondering about the via creation in Eagle. What size hole is good
to use for this procedure? I am drilling the hole using a Micro-mark running
at 6500 rpm, so I may not get a super duper clean hole, but I think that it
should still work since I am using the thinner 1/32" fr-4. What do you all
think about this?

On another note, I finally mastered the double-sided PCB creation process,
but now I am really really tired of hand soldering pins into vias. Front,
back, front, back, yuck.


thanks,
Chris


[Non-text portions of this message have been removed]

I have tried this method with minimal success.  I typically use a via hole size of 20mil, a #74 drill.  I found it easier to not laminate the board prior to drilling.  Just drill the holes, use a paint brush to apply the permatex to fill each hole, vacuum it out, then repeat for the second side.  When done, use a paper towel with a little acetone to remove the ink from the surface of the board, being somewhat careful not remove any of the permatex from the holes.

As I said, I had minimal success with this...high impedance across vias.  I now use a silver bearing ink to prep the holes and then electroplate with copper.  Electroplating turns out to be fairly inexpensive, easy, and safe, with near 100% success.

Amazon has a deal to buy 12 packages of the permatex for about $80.  If you have many holes it takes nearly a whole bottle to do one board...around $9.00 per board.  A little pricey.

Good luck.

--- In Homebrew_PCBs@yahoogroups.com, Chris Kleeschulte <laconia@...> wrote:

>
> I am going to trying using James Mitchell's plated-thru hole method this
> week and I wondering about the via creation in Eagle. What size hole is good
> to use for this procedure? I am drilling the hole using a Micro-mark running
> at 6500 rpm, so I may not get a super duper clean hole, but I think that it
> should still work since I am using the thinner 1/32" fr-4. What do you all
> think about this?
> 
> On another note, I finally mastered the double-sided PCB creation process,
> but now I am really really tired of hand soldering pins into vias. Front,
> back, front, back, yuck.
> 
> 
> thanks,
> Chris
> 
> 
> [Non-text portions of this message have been removed]
>

Chris Kleeschulte wrote: 
> I wondering about the via creation in Eagle. What size hole is good
> to use for this procedure?

The drill size depends more on everything else than on spindle, easy
answer: make a board with a bunch of vias for testing and count success
rate per drill size.
You mention eagle, it can make annular ring for vias troublesome when
doing via tending with dry film, there is a trick for easy changing this
on eagle:
http://gaussmarkov.net/eagle/padsize.html

  
> James Mitchell's plated-thru hole method 
> 

Is that method the one using car radiator repair liquid which is
conductive, with the same procedure as think&tinker use conductive ink?
There is a guy who makes it with a cheaper homegrown ink:
http://www.youtube.com/watch?v=KTNuTv_IQp4

Simao

wow! I think for now, I am going to stick to old school soldering small
wires into my vias. Then just using a board house for copies of my
prototypes. That youtube video that Simao sent was amazing, but its probably
too hardcore for me at this point. I gotta say that homebrew pcb guys are
some of the most inventive and fearless people I have ever dealt with. Since
the 90's this topic has grown by huge bounds!

Chris




On Mon, Apr 4, 2011 at 12:39 PM, Terry <twgray2007@...> wrote:

>
>
> I have tried this method with minimal success. I typically use a via hole
> size of 20mil, a #74 drill. I found it easier to not laminate the board
> prior to drilling. Just drill the holes, use a paint brush to apply the
> permatex to fill each hole, vacuum it out, then repeat for the second side.
> When done, use a paper towel with a little acetone to remove the ink from
> the surface of the board, being somewhat careful not remove any of the
> permatex from the holes.
>
> As I said, I had minimal success with this...high impedance across vias. I
> now use a silver bearing ink to prep the holes and then electroplate with
> copper. Electroplating turns out to be fairly inexpensive, easy, and safe,
> with near 100% success.
>
> Amazon has a deal to buy 12 packages of the permatex for about $80. If you
> have many holes it takes nearly a whole bottle to do one board...around
> $9.00 per board. A little pricey.
>
> Good luck.
>
>
> --- In Homebrew_PCBs@yahoogroups.com, Chris Kleeschulte <laconia@...>
> wrote:
> >
> > I am going to trying using James Mitchell's plated-thru hole method this
> > week and I wondering about the via creation in Eagle. What size hole is
> good
> > to use for this procedure? I am drilling the hole using a Micro-mark
> running
> > at 6500 rpm, so I may not get a super duper clean hole, but I think that
> it
> > should still work since I am using the thinner 1/32" fr-4. What do you
> all
> > think about this?
> >
> > On another note, I finally mastered the double-sided PCB creation
> process,
> > but now I am really really tired of hand soldering pins into vias. Front,
> > back, front, back, yuck.
> >
> >
> > thanks,
> > Chris
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>  
>


[Non-text portions of this message have been removed]

Chris Kleeschulte <laconia@...> writes:
> I think for now, I am going to stick to old school soldering small
> wires into my vias.

This is what I do.  I've found that a 28 gauge brass wire (standard
hardware store size) in a #80 hole is a snug fit - you can push the wire
through, but it doesn't move when soldering.  So I can quickly
push/solder/cut from one side, then flip the board over and solder/cut
all the other sides.

On 6/04/2011 2:47 AM, DJ Delorie wrote:
> Chris Kleeschulte <laconia@... <mailto:laconia%40gmail.com>> writes:
>
> > I think for now, I am going to stick to old school soldering small
> > wires into my vias.
>
> This is what I do. I've found that a 28 gauge brass wire (standard
> hardware store size) in a #80 hole is a snug fit - you can push the wire
> through, but it doesn't move when soldering. So I can quickly
> push/solder/cut from one side, then flip the board over and solder/cut
> all the other sides.
>
I've got a slightly different technique that works well. If I've got a 
lot of holes to do, I'll start with 8 resister pigtails. I'll often 
sacrifice a strip of new resisters for this, as I don't use through hole 
anymore. Hold all 8 side by side tight in fingers, and then grip them 
with all with needle nose pliers about 1mm from end. Fold them all at 
once. then use a good pair of shears or wide enough side cutters to cut 
all 8 off a couple of mm below the fold. Be careful if using side 
cutters as they can go flying. I've got some slightly serrated shears 
that works great for this.
Grip again with needle nose pliers, fold, and repeat. I find I can get 
at least 5/6 batches of pins (40/48 vias) that way from one lot of 
pigtails, really quite quickly.
The local shop sells resisters in packs of 8 for about 40c, so I get 
almost 100 vias from that one pack. Or you pick up a bargain bag of 
resisters and never run out of vias again.

Then once you've got a pile of them use tweezers to drop them in vias 
quickly and easily, solder all the folded sides at once, flip board and 
do them all that side.

Andrew


[Non-text portions of this message have been removed]