Just wanted to drop by and share my new creation. I ordered some samples of Pyralux Flexible Circuit material ( http://www2.dupont.com/Pyralux/en_US/index.html ) to see if I could make a replacement VB display cable (and to just experiment 😎 ). RunnerPack made a mask for the cable and emailed me the file, which I printed on my laser printer.
I was going to do it the normal way of printing on glossy paper, then using an iron to transfer the toner over to the cable, but I decided to try printing directly on the cable by using masking tape to hold it to a sheet of paper. This worked perfectly. I then dipped it in a small bowl of hot etchant (standard ferric chloride I had laying around), and within just a couple minutes the cable had completely etched, and the toner was still in perfect shape (there were a couple spots that didn’t get good toner coverage to start with, since my toner cartridge isn’t in great shape, but nothing major). I think it etched so quickly because it’s only 1/2 oz copper, compared to thicker copper used on most PCBs. This material is also a little bit thinner than the VB cable material (maybe because there’s no protective coating over the copper), so it crinkles pretty easily if you’re not careful.
Overall, the cable turned out great… this was my first attempt, and it turned out better than most regular PCBs I’ve made.
Attaching it to the display wasn’t exactly easy though. I tried tinning both sides, and then heating it up so the solder would melt and they’d stick together, but it didn’t work out too well. Eventually I just ended up running a soldering iron on the top and melting the cable to the display PCB. In the end, the display worked, but if I mess with the cable, lines appear on the screen. I think I’ll use some NaOH to dissolve the Polyimide on the display end so I can solder the tips of the cable properly. I’ll also put some tape on the bottom of the cable to prevent it from shorting anything out if it presses up against the display since it’s not soldered all the way from the front to the back. I just superglued a piece of cardboard to the cable for the stiffener so it can be inserted and removed from the socket on the VB motherboard. The cardboard is a little bit too thick, so I’ll probably find something a little thinner and use that instead.
Anyway, I just wanted to share this… I doubt I’ll mess with this too much, since the original cables themselves are holding up fine, but I thought it might be interesting to try.
If it weren’t for the connection issues, that FPC stuff would sound very handy.
I’ve got some ribbon cable shielding stuff that’s basically the same thing. I don’t remember how much I got, but it’s probably wide enough for the length of the display cable, and I got a few feet of it, so I could probably make dozens of them. The only problem is that it already has plastic on both sides. It also has a stranded wire running down it under the plastic on one side, but that can be removed.
Now that I know NaOH can dissolve the plastic, I can actually use it! Hooray!