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2012-01-02 by DaveC
I want to make a double-sided PCB on board stock that isn't cut to size. In other words, what technique can I use to align the 2 toner printouts such that the vias align? Normally you use the corners of a pre-cut board, but if you don't have that, what other options for alignment are there? Thanks, Dave
2012-01-02 by Piers Goodhew
I've recently tried the "pocket" method, which DJ Delorie has mentioned here a few times: you line sides A and B up through a light and staple them together, then just slide the PCB in. My results were pretty close, but, oh, a few mil (< 10, >= 5) out - which could be due either to either the alignment or the (non)-perpendicularity of my hand drilling or both. (my previous method: avoid at all costs, has also worked well) Keep meaning to share photos as it's not a bad board, but what with moving countries, it's not easy. PG
On 02/01/2012, at 3:54 PM, DaveC wrote: > I want to make a double-sided PCB on board stock that isn't cut to > size. In other words, what technique can I use to align the 2 toner > printouts such that the vias align? > > Normally you use the corners of a pre-cut board, but if you don't > have that, what other options for alignment are there? > > Thanks, > Dave >
2012-01-02 by Andrew Volk
Many years ago I used a variation on the pocket method. I taped the negatives to a spine of PCB material. They would be aligned as the second side was being taped on. You can align the features with the negative pinched together as long as each negative is pinched in the same distance and angle from the spine to remove parallax error. I thought that the spine would allow the two negative to be flat to the board being exposed so there was no stress on the negatives. I was able to make several consistent copies of a board this way.
-----Original Message----- From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Piers Goodhew Sent: Sunday, January 01, 2012 9:08 PM To: Homebrew_PCBs@yahoogroups.com Subject: Re: [Homebrew_PCBs] Double-sided on random-size board? I've recently tried the "pocket" method, which DJ Delorie has mentioned here a few times: you line sides A and B up through a light and staple them together, then just slide the PCB in. My results were pretty close, but, oh, a few mil (< 10, >= 5) out - which could be due either to either the alignment or the (non)-perpendicularity of my hand drilling or both. (my previous method: avoid at all costs, has also worked well) Keep meaning to share photos as it's not a bad board, but what with moving countries, it's not easy. PG On 02/01/2012, at 3:54 PM, DaveC wrote: > I want to make a double-sided PCB on board stock that isn't cut to > size. In other words, what technique can I use to align the 2 toner > printouts such that the vias align? > > Normally you use the corners of a pre-cut board, but if you don't > have that, what other options for alignment are there? > > Thanks, > Dave > ------------------------------------ Be sure to visit the group home and check for new Links, Files, and Photos: http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
2012-01-02 by Leon Heller
On 02/01/2012 05:07, Piers Goodhew wrote: > I've recently tried the "pocket" method, which DJ Delorie has mentioned here a few times: you line sides A and B up through a light and staple them together, then just slide the PCB in. My results were pretty close, but, oh, a few mil (< 10,>= 5) out - which could be due either to either the alignment or the (non)-perpendicularity of my hand drilling or both. I've used that technique a couple of times, taping the two transparencies together with masking tape folded over the edges. With care, results aren't bad, but I find that single-sided boards with wire links are quicker and easier to make. Leon -- Leon Heller G1HSM
2012-01-02 by Harvey White
On Sun, 1 Jan 2012 20:54:11 -0800, you wrote: >I want to make a double-sided PCB on board stock that isn't cut to >size. In other words, what technique can I use to align the 2 toner >printouts such that the vias align? I drill 3 extra vias, sized to fit exactly a push in map pin. I use that to align the masks or the boards (whatever you do). The trick is to have rigid pins, and to size exactly so the boards don't shift. Three pins for alignment (3 corners of a square) assure that you can't reverse a board. Harvey
> >Normally you use the corners of a pre-cut board, but if you don't >have that, what other options for alignment are there? > >Thanks, >Dave > > >------------------------------------ > >Be sure to visit the group home and check for new Links, Files, and Photos: >http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > >
2012-01-02 by RDHeiliger
I recently did a double a sided board by using two 1/32 single sided boards. Transfer top onto one, bottom onto other, etch, drill. You can even drill both at the same time if you drill alignment holes in each first, then pin them together with old drill bits. I didn’t glue them together, I use a block of polyiso foam insulation, push short lengths of wire thru the vias in both boards, and into the polyiso, solder all on the top side, flip the boards over, pushing the wires back into the polyiso, and solder the bottom side. Don’t clip the wires until both sides are soldered, or they have a tendency to slip thru when soldering the back side. The wires thru the vias end up like rivets holding the boards together.This also allows you to reflow SMD’s on both sides before soldering them together. It takes a hard look to even tell that there are two boards. RD [Non-text portions of this message have been removed]
2012-01-04 by DJ Delorie
I've done the same thing, but use 3M double sided tape sheets to tape the two halves together. Never thought of the double-smd-sided trick though...
2012-01-04 by Boman33
Actually this can easily be taken up another notch: A 4-Layer board. The backside can be a solid ground plane on one board and a power plane on the other board with a double layer of tape as insulation between them. Drill big clearance holes in the opposite board to clear wires poked through and soldered for power or ground connection. The connections will be rather large so not suitable for a tight board but a lot of projects would greatly benefit of a 4-layer board with solid ground plane and power. Bertho From: DJ Delorie Sent: Tuesday, January 03, 2012 22:14 I've done the same thing, but use 3M double sided tape sheets to tape the two halves together. Never thought of the double-smd-sided trick though... [Non-text portions of this message have been removed]
2012-01-05 by DJ Delorie
"Boman33" <boman33@...> writes: > Actually this can easily be taken up another notch: A 4-Layer board. I have already done that :-) http://www.delorie.com/electronics/usb-gpio/ The yellow-green board about the middle is a home-made 4 layer board. http://www.delorie.com/electronics/sdram/ The yellow-green board at the bottom is one of four layers for another home-made 4 layer board. I did just what you said, too - pre-drilled larger holes on the outer layers so I could manually solder to the inner layers beneath them.
2012-01-05 by Boman33
Very, very nice work DJ! What I suggested is slightly different to achieve the same result. It looks like you used a thin double sided center board with a single-sided board added on each side to get the 4 copper layers. I was suggesting to use two double-sided boards with extra insulation in the center. Again, excellent work! Bertho ========================
From: DJ Delorie Sent: Thursday, January 05, 2012 00:04 "Boman33" <boman33@... <mailto:boman33%40vinland.com> > writes: > Actually this can easily be taken up another notch: A 4-Layer board. I have already done that :-) http://www.delorie.com/electronics/usb-gpio/ The yellow-green board about the middle is a home-made 4 layer board. http://www.delorie.com/electronics/sdram/ The yellow-green board at the bottom is one of four layers for another home-made 4 layer board. I did just what you said, too - pre-drilled larger holes on the outer layers so I could manually solder to the inner layers beneath them. [Non-text portions of this message have been removed]