Soldering SMD TSSOP IC
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If you’re concerned about soldering the SMD chip, don’t be. It’s quite easy, in fact, with the right tools, it’s as easy as soldering through hole devices and when you consider that you’re soldering 28 leads, it’s actually faster than through hole, with a little practice.
You can see in the example to the right that I didn't get the chip exactly centered on the leads, but it still works fine, so good enough!
Cover the PCB leads with liquid flux. Be generous, it's OK to have too much.
Collect a fairly big glob of solder onto the tip of your soldering iron, then spread it across the leads on the PCB. Spread quickly because otherwise the flux will evaporate and then bridges will occur. This is called "tinning the leads".
Remove all of the solder from the soldering iron.
Using the tweezers, hold the IC over the leads on the PCB, and then begin pressing down on the leads. If the iron collects solder during this process, wipe it off immediately as this can create to bridges.
If bridges do occur, you can clean your iron and then use it to collect the excess solder. If that doesn't work, try using some solder wick to collect the bridge solder.
Final check - Using your multi-meter, go over the leads using the continuity mode, which hopefully sounds a tone when a connection is made. What you're looking for is that the top of the lead on the IC is connected to the PCB tracing underneath. You also need to check that the lead isn't bridged to it's neighbors. Check each lead on the IC individually.