Conductive tape?

Other Hardware General Electronics
1

I may need to patch a bunch of PCBs, and I'm not looking forward to the thought of stripping, soldering, and bonding a couple wires to 150 boards. I'm also concerned about the wires being broken off when the boards are handled by the end user.

The thought then occurred to me that I've seen something like copper tape before, and using something like that to lay down new traces would be a good solution in this instance. I figure I can stick the traces down, scrape away the insulator near the pads I want to attach them to and then bridge it with solder. And with it being so thin it will be unlikely to be damaged by the end user. But I need something fairly narrow. Less than 1/8th of an inch I'm thinking.

Does anyone know a good source for tape like this?

2

http://www.megahobby.com/18x120brushedcopper.aspx perhaps?

3

In that case, a search for
1/8" copper foil tape
yields a bunch of hits from digikey, such as:

4

I've used such tape in some designs a long while back. Some problems you might find, especially with the very narrow sizes is that the glue backing can fail in time and soldering the bridges at the end of runs seems to 'boil off' the glue at the ends. I would suggest after you install such tape runs and make the bridge connections you 'paint' the tape with some clear epoxy product to protect the tape mechanically.

Lefty

5

I understand the tape is conductive, but how do you ensure a permanent electrical
connection with the areas being repaired? Will that tape accept solder readily? Will
it hold?

I'm also concerned about the wires being broken off when the boards are handled by the end user.

Back in the early days of the IBM PC, IBM would actually ship plug-in boards that had
wires soldered on the back to fix their design mistakes.

6

Back in the early days of the IBM PC, IBM would actually ship plug-in boards that had
wires soldered on the back to fix their design mistakes.

That is standard practice throughout the whole electronics industry.

7

Telecommando:
I had a board come in just a few months ago, all surface mount components, with a couple of #30 kynar-insulated jumpers. They were there to "beef-up" the traces feeding power to a driver chip. The original designer made the traces too small and this was their fix.

Oy, any "experienced" pcb designer would know enough to lay out the power+ground with
wide traces from the get-go. There sure are a lot of people selling boards anymore, and
having little idea what they're doing. I bought a couple of boards recently, and they had
the power trace from the USB port made using a tiny 6-8 mil trace between 2 close-set
pads the user would normally solder across to make the connection, and the tiny trace was
invisible under solder mask. One can only shake their head at such stupidity.