Soldering Joints with Adhesive Copper Tape

As someone suggested you need to overlap not try and bridge the gap. IME the adhesive acts like a solder resist and is a pain to clean off although its possible to tin through it if you get it hot enough, might be easier to bridge the gap with a piece of upisde down tape.

Incidently I make my pcbs by isolating tracks on copper clad board with a very small burr in a drill. you can make a simple pcb in a few minutes literaly. the best burr ive found to use so far is a (broken) 1mm solid tunsgten carbide milling cutter, with a 1/8" shank wich is attatched directly to the 1/8" shaft of a motor wich came out of a cordless scredriver. ive heard other people use dental burrs but ive not come accros one of those yet.

Colin =^.^=

Lay down one of the "traces" directly onto the substrate (pc board??). Lay down the next trace where you want it to go and overlap the first trace by a few mm. Bend that overlapping trace BACK underneath onto itself so that adhesive sticks to adhesive. Clean the area where the two traces overlap with alcohol on a swab so that any trace of adhesive is removed.

If you don't use this bend-back trick, as soon as the hot iron touches the top (overlapping) trace it will melt adhesive onto the bottom trace and you never will get solder to stick properly.

Solder clean copper to clean copper. We do it all the time when adjusting copper foil antenna elements to resonance. As to life, I've got one element that stays outside most all of its life and it has been going since 1978 without a hitch.

Jim

SNIP

those

Ask your dentist! I got many of these used burrs, who are to blunt for dental work, but still usable for electronics by simply asking. Sometimes my dentist collected them for me till my next visit.

Wim

Or, set up the butt joint and lay a "bridge" piece of tape - upside down - across the joint.

I might try folding a bit of the strip end, pound down and then solder. Skips the adhesive removal. It's copper above and below and solder wicks underneath the strip. It's a difference of about 0.3mm vs 0.2mm...could be tolerable in my app.

It's been a long time since I did that machine method..I'll keep it in mind. :) Reminds me of the time I wanted to try a sand blasting stencil and take the circuit board to a DIY sand blaster shop.

D from BC

Prior to this post, I posted experimenting with that folding technique. Deja vu :) I think I did this in an RF course about 15 years ago..Totally forgot..

Thanks for the confirmation.. :) D from BC

I'm trying the folding technique now.. It's a little annoying that the folded end springs up a bit due no stick but got that fixed by holding the joint together by using the point of an xacto knife (high thermal resistance).

Looking good :) D from BC

In addition to trying the folding technique as posted... I also tried the above technique too... Solder does displace the adhesive but there are black bits on top of the joint (burnt adhesive) ... The joint is shiny and the crap on top of the joint is probably harmless. It's just fiddly because the "bridge" piece has to be held in place before soldering. D from BC

Try a lap joint, but first get all of the adhesive off the part of the top tape that will do the lapping. Rough up the copper and flux it, lay it down on top of the bottom tape, and it should just suck the solder up. This is called "sweat soldering" - with clean copper and flux, the solder should just wick up in between the tapes.

Good Luck! Rich

The adhesive oozes out and seems a half-reasonable resist. I have used it to assemble double-sided PCB panels into a RF-tight enclosure. It works, but needs a lot of heat and about an 80W iron to drive out the adhesive. Now I stick with 32 thou tin-plated steel.

To make a quick'n'dirty PCB, I grind out the unwanted copper with a

3/16 burr in a Dremel tool. With a bit of practice, it's the quickest and easist method I have found. (But not the most noise-free, nor mess-free)

The solder they use on stained glass is more like 50:50 tin:lead, unlike electronic solder which is 63:37 or 60:40. The less eutectic solder has a plastic state where you can push it around, so it's a lot easier to bridge over the gaps.

John

Have you physically cleaned the joint (scotchbrite, sandpaper) before starting? I'd do that, and burnish (rub down firmly with a smooth object) the upper edge onto the lower. Actually, burnish, then clean. If still having problems after that, I'd see if the adhesive is the trouble by folding back the end of the top strip so no adhesive is exposed. If that makes the joint "too thick", but otherwise solves it, find a solvent that cuts the adhesive, and remove the adhesive from the tip of the top piece (and physically clean that section of the bottom) before assembly.

--
Cats, coffee, chocolate...vices to live by

I used to test and calibrated low phase noise synthesizer modules. The low frequency was set by soldering a strap form the strip inductor to the ground plane to shorten the strip inductor. We were supposed to use a wide piece of tin plated brass strap, but I used the backing strip from Berg and AMP terminals from our wire room. It had small holes for the machine to advance to the next position. They were great for holding it down while it was soldered to the board, then I would flow solder over the hole. It looked exactly like the brass stock but soldered better, and was easier to work with.

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida