The continuing saga of the 0.4 mm pitch KL03 ARM microcontroller. If you haven’t yet done so, read part I and part II.
Today, I have a look at the good, the bad, and the ugly – or more accurately, the good, and the bad and ugly. As I expected, I was quite pleased with the job done here in house. The board is nice and clean, the parts are well centered, and the solder joints are solid. No surprise here.
Here’s a top view of one we did here in Screaming Circuits:
Next, I’ve got one that I did at home. It actually surprised me and came out better than I had expected. Here’s a top-down view of the one I did at home with home-grade tools (No, I didn’t intentionally make it look bad. The board surface is just a bit shinier than the one above.):
Of course, “better” is a relative term. I didn’t say good. I could call this both bad and ugly. I did manage to center the parts quite well — that took a lot of careful nudging with sharp tweezers and and an X-Acto knife blade.
All of those little round shiny spots are solder balls. That’s what happens when you get too much solder on the board, get solder off the pads, or have the wrong reflow profile. They might look harmless, but if there are too many under the chip, the connections could be shorted.
The fillets on the 0201 capacitor are a little lean on solder in the one I did, and there’s a solder ball on the right side, but, again, it looks better than I expected.
Next time, I’ll post the x-rays and show what’s under the hood.
Duane Benson
Carburetors, man.
That’s what life is all about