I managed to cut the pads off the end of one of my strips while trying to remove the silicone. It’s obvious the tracks continue further back, so I scraped the coating off to expose the copper, but whatever I do the solder won’t wet on it.
Anybody know why, and how I can fix this?
I’ve had challenges with that as well, which is why I now buy non-waterproof strips. Try adding some flux to the pads before adding solder.
I fluxed the flux out of it, no dice. Also tried isopropyl alcohol.
super light scuffing with emery board or 1200 wet 'n dry paper… ?
If you have any copper-tape you could ‘mechanically’ fix it… sparkfun/adafruit have it (or did)…
You need to scuff the pads. There’s a thin layer of the silicon bonded on them and unless you take that off, you’re not going to be able to get any solder to adhere.
Sandpaper grit 1000+ usually does the job.
That silicon is an f’ing nightmare and makes the surface practically unsolder-able. I’m pretty sure that is why many of the manufacturers have moved away from doing that and use a rubber tubing that doesn’t interfere with the ribbon and the copper leads.
It’s easier/quicker to manufacture; just get the raw strip and pull it into the tube. With the molded ones, it’s a much slower process with the whole strip going into an extrusion machine that puts the heated silicone on.
It’s better to just wrap and bend it if its been molded like that and avoid cutting it. Its a bit more weather proofed i suppose but a lot harder to cut and resolder.
I don’t think it’s the silicon coating that’s getting in the way in this instance—I’ve had a similar problem with uncoated strips. I think what is going on is the gloss (paint? sealant?) on top of the white laminate coating over the flex PCB is melting on top of the exposed copper and the solder won’t stick to it. So in order for this to work at all I have to abrade away all of that, which is practically impossible.
Try rubbing it with a bit of fine sand paper before trying to tin it
Try rubbing it with a bit of fine sand paper before trying to tin it
I just scrape the ‘outer layer’ with an Exacto knife until I have bright copper, that is solder-able. That or sandpaper should work for you.
