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Alignment for double-face boards

Alignment for double-face boards

2010-04-06 by Alessio Sangalli

Hi, what is your "technique" to properlu align double-face boards? I am 
using toner transfer and a laminator. So far thge best method I've found is:

1) print out the two faces on special paper. Make some holes in 
reference points, I use the mounting holes.
2) put only one "face" in the laminator with the board and pass it a 
couple of times until it is fully "attached".
3) wait for it to cool down
4) drill holes in the PCB using the holes in the paper as reference
5) align the second face on the back and put it in the laminator, and 
pass it several times

6) proceed with removal and etching etc

Do you have any advice?
bye
as

Re: Alignment for double-face boards

2010-04-07 by sailingto

That sounds like a very good procedure - I just might try it. I usually drill a .021 hole in the corner mounting holes, with a tiny hole thru the same mounting hole in the paper, press a pin thru the paper and board holes to hold paper in alignment, start in laminator and as board gets started good, remove pins so the board can go on thru.  "Most" of the time this works pretty good.

Using as large a pad as possible, and not having a hole in the center of copper pad allows drilling all from one side.  "IF" the other side isn't perfect, it is usually close enough to be in the pad on other side.  Not perfect, but works. 

I think I'll try your method on next board.

Ken H>


--- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@...> wrote:
Show quoted textHide quoted text
>
> Hi, what is your "technique" to properlu align double-face boards? I am 
> using toner transfer and a laminator. So far thge best method I've found is:
> 
> 1) print out the two faces on special paper. Make some holes in 
> reference points, I use the mounting holes.
> 2) put only one "face" in the laminator with the board and pass it a 
> couple of times until it is fully "attached".
> 3) wait for it to cool down
> 4) drill holes in the PCB using the holes in the paper as reference
> 5) align the second face on the back and put it in the laminator, and 
> pass it several times
> 
> 6) proceed with removal and etching etc
> 
> Do you have any advice?
> bye
> as
>

Re: [Homebrew_PCBs] Re: Alignment for double-face boards

2010-04-07 by Harvey White

On Wed, 07 Apr 2010 02:20:19 -0000, you wrote:

I have a supply of .023 board available, single sided.

To make use of that, I put each side on a piece of board.  I have four
or five alignment holes on each side.  Each board will be drilled
through the alignment holes using a drill that matches a map push pin.
The stiffer the pin and fatter, the better.  Small pins wobble,
allowing misalignment.

Etch the boards as usual, do not combine the boards yet.  Drill the
alignment holes after etching and plating.

Combine the boards, top and bottom to check alignment.  You may drill
a hole or two in a non critical location if  you wish.

I epoxy the boards together with slow epoxy.  It gives me enough
working time and the ultimate setup and hold time are no different (24
hours).

Shear boards to size, drill.

Good enough alignment to use 0.023 drills for vias, with about .043
pads for good solder joints (stitched for high density boards), or use
eyelets as needed for lower density boards.


Works well for me.

Harvey
Show quoted textHide quoted text
>That sounds like a very good procedure - I just might try it. I usually drill a .021 hole in the corner mounting holes, with a tiny hole thru the same mounting hole in the paper, press a pin thru the paper and board holes to hold paper in alignment, start in laminator and as board gets started good, remove pins so the board can go on thru.  "Most" of the time this works pretty good.
>
>Using as large a pad as possible, and not having a hole in the center of copper pad allows drilling all from one side.  "IF" the other side isn't perfect, it is usually close enough to be in the pad on other side.  Not perfect, but works. 
>
>I think I'll try your method on next board.
>
>Ken H>
>
>
>--- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@...> wrote:
>>
>> Hi, what is your "technique" to properlu align double-face boards? I am 
>> using toner transfer and a laminator. So far thge best method I've found is:
>> 
>> 1) print out the two faces on special paper. Make some holes in 
>> reference points, I use the mounting holes.
>> 2) put only one "face" in the laminator with the board and pass it a 
>> couple of times until it is fully "attached".
>> 3) wait for it to cool down
>> 4) drill holes in the PCB using the holes in the paper as reference
>> 5) align the second face on the back and put it in the laminator, and 
>> pass it several times
>> 
>> 6) proceed with removal and etching etc
>> 
>> Do you have any advice?
>> bye
>> as
>>
>
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>

Re: Alignment for double-face boards

2010-04-07 by sailingto

I have used that method and it does work good - Just seems to be more hassle than doing a single double sided copper board.  For critical alignments it could work better.  I'm not sure it's really all that much more hassle - just a "mind frame" I got in.

I'll try it again.  I do have some thin board material - it's double sided, but once it's etched it will be single sided then :)

I have though about trying a 3-layer board - maybe putting the ground plane (or power?) layer in the center.

Ken H>

--- In Homebrew_PCBs@yahoogroups.com, Harvey White <madyn@...> wrote:
Show quoted textHide quoted text
>
> On Wed, 07 Apr 2010 02:20:19 -0000, you wrote:
> 
> I have a supply of .023 board available, single sided.
> 
> To make use of that, I put each side on a piece of board.  I have four
> or five alignment holes on each side.  Each board will be drilled
> through the alignment holes using a drill that matches a map push pin.
> The stiffer the pin and fatter, the better.  Small pins wobble,
> allowing misalignment.
> 
> Etch the boards as usual, do not combine the boards yet.  Drill the
> alignment holes after etching and plating.
> 
> Combine the boards, top and bottom to check alignment.  You may drill
> a hole or two in a non critical location if  you wish.
> 
> I epoxy the boards together with slow epoxy.  It gives me enough
> working time and the ultimate setup and hold time are no different (24
> hours).
> 
> Shear boards to size, drill.
> 
> Good enough alignment to use 0.023 drills for vias, with about .043
> pads for good solder joints (stitched for high density boards), or use
> eyelets as needed for lower density boards.
> 
> 
> Works well for me.
> 
> Harvey
> 
> 
> 
> 
> >That sounds like a very good procedure - I just might try it. I usually drill a .021 hole in the corner mounting holes, with a tiny hole thru the same mounting hole in the paper, press a pin thru the paper and board holes to hold paper in alignment, start in laminator and as board gets started good, remove pins so the board can go on thru.  "Most" of the time this works pretty good.
> >
> >Using as large a pad as possible, and not having a hole in the center of copper pad allows drilling all from one side.  "IF" the other side isn't perfect, it is usually close enough to be in the pad on other side.  Not perfect, but works. 
> >
> >I think I'll try your method on next board.
> >
> >Ken H>
> >
> >
> >--- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@> wrote:
> >>
> >> Hi, what is your "technique" to properlu align double-face boards? I am 
> >> using toner transfer and a laminator. So far thge best method I've found is:
> >> 
> >> 1) print out the two faces on special paper. Make some holes in 
> >> reference points, I use the mounting holes.
> >> 2) put only one "face" in the laminator with the board and pass it a 
> >> couple of times until it is fully "attached".
> >> 3) wait for it to cool down
> >> 4) drill holes in the PCB using the holes in the paper as reference
> >> 5) align the second face on the back and put it in the laminator, and 
> >> pass it several times
> >> 
> >> 6) proceed with removal and etching etc
> >> 
> >> Do you have any advice?
> >> bye
> >> as
> >>
> >
> >
> >
> >
> >------------------------------------
> >
> >Be sure to visit the group home and check for new Links, Files, and Photos:
> >http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
> >
> >
> >
>

Re: [Homebrew_PCBs] Re: Alignment for double-face boards

2010-04-07 by Harvey White

On Wed, 07 Apr 2010 12:18:45 -0000, you wrote:

>I have used that method and it does work good - Just seems to be more hassle than doing a single double sided copper board.  For critical alignments it could work better.  I'm not sure it's really all that much more hassle - just a "mind frame" I got in.

I've done both.  I find it easier to align two made boards than to
align two pieces of pulsar paper and expect them to keep alignment
during the runs through the laminator.  I'll agree that the epoxy step
is a pain, but it isn't all that much of a problem.

I use the push pins to align the boards (untrimmed), then tape the
boards together on the outsides, preserving the alignment.  Removing
the push pins and sandwiching the board between two pieces of marble
makes for a flat board.  (cheap home store marble, remarkably flat).

The advantage is that if one layer does not etch well, you throw it
out and then make the single layer.
>
>I'll try it again.  I do have some thin board material - it's double sided, but once it's etched it will be single sided then :)
>

You could use that for a ground layer, if you want, but that's just as
much hassle as a full layer, but not quite so critical in alignment
perhaps.

>I have though about trying a 3-layer board - maybe putting the ground plane (or power?) layer in the center.

Ground is typically better.  The only ways I know would be to 

1) more or less solid ground plane, donuts around pads to keep any
possible jumpers from shorting.  Ground connections made from one
layer to ground plane only, or from one layer to ground/vcc only (if
you're doing a double sided inner layer).

Connections are made by large holes in upper layers and wire jumpers.
Not all that elegant, I think.

2) use eyelets.  However, eyelets have to be done as follows:

a) probably a two layer board for the center plane, or one.  Eyelet
needs correspondingly larger hole on the non-connected plane, so for a
top plane connected to ground, you have 1) pad on top, 2) no copper
area on facing layer to top plane, 3) ground plane on back of inner
layer, and 4) bottom layer.  

This way, all ground connections go from top to ground plane, bottom
layer cannot connect to ground plane directly (unless using method #1
above), VCC connections can go from back of plane to second layer
only.  That allows you to use eyelets to connect two layers.  If your
eyelets are not long enough, you can't use them to connect the bottom
and top layers directly.

Haven't tried either method, though.

Harvey
Show quoted textHide quoted text
>
>Ken H>
>
>--- In Homebrew_PCBs@yahoogroups.com, Harvey White <madyn@...> wrote:
>>
>> On Wed, 07 Apr 2010 02:20:19 -0000, you wrote:
>> 
>> I have a supply of .023 board available, single sided.
>> 
>> To make use of that, I put each side on a piece of board.  I have four
>> or five alignment holes on each side.  Each board will be drilled
>> through the alignment holes using a drill that matches a map push pin.
>> The stiffer the pin and fatter, the better.  Small pins wobble,
>> allowing misalignment.
>> 
>> Etch the boards as usual, do not combine the boards yet.  Drill the
>> alignment holes after etching and plating.
>> 
>> Combine the boards, top and bottom to check alignment.  You may drill
>> a hole or two in a non critical location if  you wish.
>> 
>> I epoxy the boards together with slow epoxy.  It gives me enough
>> working time and the ultimate setup and hold time are no different (24
>> hours).
>> 
>> Shear boards to size, drill.
>> 
>> Good enough alignment to use 0.023 drills for vias, with about .043
>> pads for good solder joints (stitched for high density boards), or use
>> eyelets as needed for lower density boards.
>> 
>> 
>> Works well for me.
>> 
>> Harvey
>> 
>> 
>> 
>> 
>> >That sounds like a very good procedure - I just might try it. I usually drill a .021 hole in the corner mounting holes, with a tiny hole thru the same mounting hole in the paper, press a pin thru the paper and board holes to hold paper in alignment, start in laminator and as board gets started good, remove pins so the board can go on thru.  "Most" of the time this works pretty good.
>> >
>> >Using as large a pad as possible, and not having a hole in the center of copper pad allows drilling all from one side.  "IF" the other side isn't perfect, it is usually close enough to be in the pad on other side.  Not perfect, but works. 
>> >
>> >I think I'll try your method on next board.
>> >
>> >Ken H>
>> >
>> >
>> >--- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@> wrote:
>> >>
>> >> Hi, what is your "technique" to properlu align double-face boards? I am 
>> >> using toner transfer and a laminator. So far thge best method I've found is:
>> >> 
>> >> 1) print out the two faces on special paper. Make some holes in 
>> >> reference points, I use the mounting holes.
>> >> 2) put only one "face" in the laminator with the board and pass it a 
>> >> couple of times until it is fully "attached".
>> >> 3) wait for it to cool down
>> >> 4) drill holes in the PCB using the holes in the paper as reference
>> >> 5) align the second face on the back and put it in the laminator, and 
>> >> pass it several times
>> >> 
>> >> 6) proceed with removal and etching etc
>> >> 
>> >> Do you have any advice?
>> >> bye
>> >> as
>> >>
>> >
>> >
>> >
>> >
>> >------------------------------------
>> >
>> >Be sure to visit the group home and check for new Links, Files, and Photos:
>> >http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>> >
>> >
>> >
>>
>
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>

Re: Alignment for double-face boards

2010-04-07 by awakephd

I have tried both of the procedures described below, with varying results. The last board I did, however, I kept having trouble getting everything to line up using either of these. Finally, I wiped the board clean on both sides and tried something else -- something I had tried before, with only mediocre results, but since I was having so much trouble I decided to give it another try:

I printed out both sides, put them together with the toner facing each other, and held them up to the light so that I could line them up exactly; then I stapled the sheets together, leaving room to put the board into the "pocket." I put the board in and ran this through the laminator; once the paper was stuck down, I cut off the excess (including the staples) and ran it through enough times to be sure I had a good transfer. The result was the best I've ever achieved -- essentially perfect as far as my naked eye can see.

I'm not sure if I just got lucky this time, or it I just didn't do it very well when I tried it before. The last time I tried this was before I had a laminator, so I was using an iron; maybe that made the difference. In any case, on my next board I plan to try this first and see if I can reproduce the excellent result I got this time.


--- In Homebrew_PCBs@yahoogroups.com, "sailingto" <sailingtoo@...> wrote:
Show quoted textHide quoted text
>
> That sounds like a very good procedure - I just might try it. I usually drill a .021 hole in the corner mounting holes, with a tiny hole thru the same mounting hole in the paper, press a pin thru the paper and board holes to hold paper in alignment, start in laminator and as board gets started good, remove pins so the board can go on thru.  "Most" of the time this works pretty good.
> 
> Using as large a pad as possible, and not having a hole in the center of copper pad allows drilling all from one side.  "IF" the other side isn't perfect, it is usually close enough to be in the pad on other side.  Not perfect, but works. 
> 
> I think I'll try your method on next board.
> 
> Ken H>
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Alessio Sangalli <alesan@> wrote:
> >
> > Hi, what is your "technique" to properlu align double-face boards? I am 
> > using toner transfer and a laminator. So far thge best method I've found is:
> > 
> > 1) print out the two faces on special paper. Make some holes in 
> > reference points, I use the mounting holes.
> > 2) put only one "face" in the laminator with the board and pass it a 
> > couple of times until it is fully "attached".
> > 3) wait for it to cool down
> > 4) drill holes in the PCB using the holes in the paper as reference
> > 5) align the second face on the back and put it in the laminator, and 
> > pass it several times
> > 
> > 6) proceed with removal and etching etc
> > 
> > Do you have any advice?
> > bye
> > as
> >
>

Re: [Homebrew_PCBs] Re: Alignment for double-face boards

2010-04-07 by Dylan Smith

For TT, I don't do anything at all complicated.

All I do is print the two toner transfer sheets.
Hold them face to face with a light behind them, bright enough to see 
the vias (the back door of the house when the sun is shining works 
remarkably well, other than that, a 50W lamp).
When aligned, tape one end of the sheets to form a hinge between the two 
sheets.
Double-check the alignment.

I've done dozens of boards this way (my second ever board was 2 sided) 
and I've only had one that was a bit off - and even then, it wasn't 
sufficiently off that it couldn't be used. All the other boards were 
perfect. I've done boards with 8/8 track/gaps this way without problems. 
I think overcomplicating the registration process can make things harder.

El 07/04/10 18:40, awakephd escribi\ufffd:
> I have tried both of the procedures described below, with varying results. The last board I did, however, I kept having trouble getting everything to line up using either of these. Finally, I wiped the board clean on both sides and tried something else -- something I had tried before, with only mediocre results, but since I was having so much trouble I decided to give it another try:
>

Re: Alignment for double-face boards

2010-04-07 by James

--- In Homebrew_PCBs@yahoogroups.com, Dylan Smith <dyls@...> wrote:
>
> For TT, I don't do anything at all complicated.
> 
> All I do is print the two toner transfer sheets.
> Hold them face to face with a light behind them, bright enough to see 
> the vias (the back door of the house when the sun is shining works 
> remarkably well, other than that, a 50W lamp).
> When aligned, tape one end of the sheets to form a hinge between the two 
> sheets.
> Double-check the alignment.
> 
> I've done dozens of boards this way (my second ever board was 2 sided) 
> and I've only had one that was a bit off - and even then, it wasn't 
> sufficiently off that it couldn't be used. All the other boards were 
> perfect. I've done boards with 8/8 track/gaps this way without problems. 
> I think overcomplicating the registration process can make things harder.
> 


Second that, I did exactly this recently, only I was using a bright flashlight. It was easy and the alignment came out perfectly on the first try.

Re: [Homebrew_PCBs] Re: Alignment for double-face boards

2010-04-07 by Alessio Sangalli

On 04/07/2010 10:40 AM, awakephd wrote:

> I printed out both sides, put them together with the toner facing
> each other, and held them up to the light so that I could line them
> up exactly; then I stapled the sheets together, leaving room to put
> the board into the "pocket." I put the board in and ran this through

I tried this but I didn't get it aligned very well. Do you keep the full 
sheets or you trim them?

In this case, the size of the toner to transfer is almost as big as the 
copper board itself, so I had the added problem to properly "center" the 
toner on the board.


bye
as

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