Project Updates for 2/11/2014

So I went ahead and after about 5 tries, I was able to get a circuit board that looked reasonably good. Things I learned during this time include:

  1. Drill holes and use those for alignment.
  2. Use a cardboard jig to help steady the design.
  3. Keep running the board through until the parchment paper looks like waxed paper (no design stuck to it). It took me 8 times for the good one.
  4. Wipe the board with acetone prior to applying the design.
  5. Give the laminator plenty of time to warm up.

So I transferred the artwork to the board, etched it (wasn't quite as scary as I thought), and tinned the board. Then I drilled holes. I counted 310 holes in the board (including standoff 5 holes). As I was drilling, I noticed that one side of the board was misaligned by about a millimeter. I did as good of a correcting job as I could.

There was only 1 trace that was broken from etching, but I can solder a wire across that. During drilling, I broke another due to the misalignment. I was able to solder a wire across that. Electrical test were all good. I had a minimal amount of scraping/breaking traces that needed to be done.

Then I started soldering. I was able to get the smt devices on with no problems. The through-holes are where it gets rough. Since I am soldering on both sides of each pin because I don't have through-hole plating, nor do I have any vias, the soldering portion is much more difficult. That means I have to solder around 600-650 points of contact. So far soldering has been going well. I was going quickly, but I did a quick bit of testing and realized I had solder gaps. So after hunting them all down and fixing them, I started performing frequent tests as I went along. I'm roughly 60% done at this point with the soldering. I ended up breaking a tiny trace between 2 larger traces. I soldered a wire in between and after I verified that nothing was touching, I took some clear nailpolish and coated the wire, which also glued it in place. I like to start with the difficult to impossible things and work my way to the easier stuff, because once they are addressed, then the easier things are easier to troubleshoot if stuff does go wrong.

Anyways, it's more soldering at this point, so I'll update this when I'm done. Hopefully that will be tomorrow or the next day.

Posted in Old Posts 11 Feb 2014