What's the easiest way to solder TSSOP parts?

Question

I'm limited by DIP so I want to branch out but my hand is shaky as it is with DIP so I can't even imagine trying to solder TSSOP. Are there easy methods for this? Do I need better equipment? I heard of some cooking method?

Found this which looks way too easy: https://www.youtube.com/watch?v=5uiroWBkdFY

What's going on here, what's that paste and is it that easy?

Answer 1

Soldering TSSOP and TQFP is a lot easier than you might think.

Things you need:

1. A reasonable soldering iron.
2. A flux pen
3. Fine solder
4. A flux pen
5. Another flux pen.

You can see from that list what I deem the most important item. Flux. Lots of it.

How I hand-solder TQFP and TSSOP:

1. Flood the area with flux.
2. Position the package correctly
3. Tack down two corners. Don't worry about excess solder.
4. Flood the area with flux.
5. Solder all the rest of the pins. Again, don't worry about excess solder.
6. Flood the area again with flux.
7. With a clean soldering iron re-flow the excess solder and allow it to wick onto the iron. Keep cleaning the iron to allow more to wick on.

In extreme cases you might want some solder braid to assist the wicking.

By "flood the area with flux" I mean make it swim in flux. Make a puddle of it so the chip sits there like a Labrador puppy in its own wee.

Finally I give it a bath in Isopropyl Alcohol to wash off the excess flux (which gets rather sticky in large quantities). A toothbrush helps to get it spotless.

Answer 2

I use a modified drag solder, a technician taught me a million years ago. With that you can solder down even huge TQFP parts in just a few minutes. You don't even need a fine tip iron if you don't have one. I went with this technique because at the time I was just learning and solder bridges were very frustrating so I decided to "embrace the bridge" and make it part of my process. Oh and the cool thing is you can do this even with a crummy soldering iron.

I like to have a pick, some solder braid, and a little flux on hand if necessary. You can use what's called a hoof tip if you have one but now I just use whatever tip I have.

• Pick

• Solder braid (buy the kind with flux in it already)

• Flux pen

Now all you have to do is put a little flux down, put the part down and try to line it up on all sides. This can be annoying but the more time you spend doing this the easier it will be later on. I usually hold it down with my finger, then put a little solder on the end of the iron tip and tack one pin down in the corner. Then I move to the opposite corner and use my finger or the pic to fix the final alignment and then tack that corner down.

Now your going to put a little solder ball at one end of the row of pins, and using your iron at an angle drag that solder across all of your pins. Someone who's good at it can just do it, but I find I like to follow along with my pic and just swipe out any solder shorts. If you miss one it's simple to go back and just heat those pins with the iron and swipe it out. When you get to the end if you made too big of a solder ball just pull it off with your solder wick.

That just means putting the braid over the solder ball and heating with the iron. The solder will flow into it and you can pull it off while it's still hot.

Here's a video of a guy doing it in about 2 seconds :)

Now I usually do this under a microscope like this but you might be able (be young enough :) to do it under a magnifier.

Now you did say easiest right? I have a lot of fancy toys at work so there are easier ways, like handing it to your trained technician and asking her to solder it for you. Or having a $50k rework machine that picks the part up, aligns it, dips it in solder paste, puts it down and uses hot air to solder it in place.

Good luck, all it takes is a little practice to get good at it. It's a good skill to have as an engineer.