The Final Expansion 3 cartridge (an SD card floppy drive emulator and RAM/flash memory card) build that I've started for use with my VIC-20 has several surface mount components, and two of these are capacitors so small that I was afraid I was going to lose them. It's not an exaggeration to say they could be mistaken for salt crystals. Perhaps the kit should have provided a spare or two just in case. ;-)
Here are photos of my work.
What I found most difficult was holding the parts precisely in place while soldering them. The way I tried was to flow solder onto the pads and then put a little flux on that and place the parts and touch them with the iron, reflowing the solder. This was hard to do, and especially with the C6 and C7 capacitors. They are so much smaller than I expected and it was very hard to center the parts over the pads. Even with tweezers it was a task. Notice in the photos above C7 is off center, but I checked it carefully with my meter and it seems okay so I decided to go with it.
Maybe pre-tinning the pads was a bad idea because it was hard to make the parts rest completely flat against the board. Another idea might have been to use solder wick to remove excess solder before placing the parts, and then putting a tiny blob of solder on the tip of the iron and applying it to the capacitor?
So, if I'm going to become good at surface mount work I'm going to need a lot more practice but this project is mostly thru hole work.
Onward and upward!
1 comment:
I am not that brave. All my electronics projects are through hole only. It is getting to be a hard line to hold though - several kits I have been interested in have surface mount components.
I watched a video of a guy building a whole board just packed with SMD components - he was using a microscope and had the really cool turn table that the boards sat on. The outside edge of the turntable has small little cups that SMD components sat in. It was really cool - but looked expensive.
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