Soldering the Chips

Last weekend I got as far as getting the clock chip soldered on and working, which felt like a bit of an achievement...

Soldering on the small chips is definitely not easy. In the end I was thankful that I have a microscope, and I did the soldering under it. You get used to zeroing in with the soldering iron and tweezers into the field without melting anything on the way, and it geat to see exactly how the solder is flowing. Maybe my multicore is too big, but I found it very difficult to get anything less than a lot of solder onto the joint. Still, in the end it seemed to flow okay, I got almost no spills, and tests so far seem to indicate that it works, so I think it will do. The picture attempts to show how the solder steeps up against the edge of the pins on the clock chip. I can only guess whether it runs underneath ok.

To check this, I got out my very old and cranky oscilloscope, and got this picture of the quadrature signals at 7MHz, so it looks like the oscillator is okay, and the PIC is programming it okay.

I had one doubt here, as I want to control the oscillator from the add-on USB module when it arrives, and the connection pins seem to be underneath the 8-pin switch module, obviously designed as an alternative to the 8-pin PIC. In the end I mounted the switch above the board, as high as its pins would allow. This will make it easy to cut off if I need to remove it later. On the other hand, the I2C programming pics can be soldered onto underneath the board, so simply removing the PIC should be enough to free up the oscillator chip programing pins later. 

That was all I had time for last weekend, but it felt like I was getting somewhere.