
How to Solve the Soldering Problem of HDMI Connector - Makerfabs
https://www.makerfabs.cc/article/makerfabs-daily-solving-the-soldering-problem.html
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blackflame
Are there classes one could take that give hands on tutorials on soldering
technique? It’s amazing to me how people are able to solder such fine traces
or even remove an entire chip from a Mobo without damaging it. Where can you
learn these skills because the school I went to (ucla) certainly didn’t have
any

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ksaj
This might sound like a non-answer, but there is no singular technique. I
learned to solder when I was a tween. I am sure that the work I did was more
on the terrible side when I started out. But I got good at it simply by
looking at professional solder connections and trying to replicate the look. I
even ended up learning how to avoid cold solder joints just by the colour and
texture of the melting solder before I knew cold solder joints were a thing.
And I thought I was quite clever tinning my leads before soldering them to the
board, until I found out that's what you're supposed to do anyway.

So the answer is merely - practice. Everything there is to know about
soldering can be taught in about 5 minutes. But getting good at it requires
simply... doing it. It is intuitive enough that if you _try_ to make it look
professional, you'll fall into good practice fairly quickly.

Recently I saw a video of a guy soldering GPIO headers on a Raspberry Pi Zero,
and I was surprised at how different his technique is than mine. But we both
solder super cleanly.

It made me realize something: Ever watch people writing something on paper?
You easily notice there are so many ways people hold and maneuver a pencil it
isn't funny, but the end result is pretty much the same. You really just
develop your own method, and chances are your first guess will be really close
to the way you'll settle into it.

Soldering cleanly is easier than writing cleanly. I'm a lefty, so your mileage
may vary on that one.

As for removing soldered things, I always took great glee in the fact that the
device you need for doing that is called a Solder Sucker. There are at least 2
types - a rubber bulb form that sucks solder up in exactly the way you'd
expect, and the other is more of a spring loaded cylinder that you load with
your thumb, and fire with your index finger.

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blackflame7000
Thanks for sharing your experience! I've been soldering for quite some time
but even still there is a limit to my precision that seems magnitudes of
orders worse than the ability of others. I guess that's why I'm not a surgeon
haha.

Follow up question, how do you know what the right temperature for the iron
should be or a particular solder/desolder? Too hot and you'll burn the PCB but
too cold and you'll just make a mess of scratches/half melted solder.

~~~
ksaj
Yea, I forgot about that - you _can_ burn the board or piece you are soldering
or desoldering. There is a sort of rhythm between when the solder starts to
flow and when you remove the iron and/or trigger the sucker. The moment you
"get it" you'll be able to do it every time without thinking. Kinda like using
clutch on a motorcycle - hard as heck when you're trying to figure it out,
then second nature when once you get muscle memory happening.

You pretty much have to look at the two things that will be connected, aim
your iron in whatever direction will make the solder flow the most direct way,
then get in / out in a fairly swift (but not rushed) move. Make sure the
solder looks like mercury - sometimes the surface isn't melted all the way
(parts of it look dull, or you can see it "stretch" when moving the iron) and
you end up with either cold joints, or an ugly partly roasted area - or worse,
solder bulging through the other side and burning components if it manages to
get hot enough to melt properly. If your solder has flux "built in," the
solder should flow really easily. If the solder forms a blob or ball on the
iron, the iron isn't hot enough yet, or you don't have enough flux. You'll
learn to identify which one it is by observation. The colour/shininess of the
solder is a good hint, though. If it happens, wipe it off, let it heat a bit
longer, and try again.

I _would_ say "never let solder build up on the iron" except that's actually
pretty much the technique the GPIO guy I mentioned was using - he melted it
onto the iron separately, then quickly placed it. I would assume your iron
needs to be sufficiently hot to ensure you don't end up with cold solder
joints, but all of his were really clean. But definitely don't let flux build
up anywhere, as it'll eventually burn and make things ugly.

This is really the heart of soldering - knowing instinctively how fast the
solder will begin to melt, and in which direction it will flow. That you
obtain from practice and paying attention to your results. Not just saying
"yea, it's sloppy" but asking yourself what you did wrong and correcting it on
the next pin. Solder with intent.

Depending on what you are soldering, you might benefit from using clips until
you have the skill down. That way you're not trying to focus on positioning
pieces _and_ soldering them at the same time. Clips also pretty much guarantee
you won't burn anything.

EDIT: About "scratches" \- you only need to hold the gun against the parts to
be soldered - no pressure (no quid quo pro! kidding...). Literally you never
need to press hard enough to scratch even if you're moving the iron around.
You can use the pointy tip for stability, but you never need to push.

It probably feels like pushing harder on it makes the solder melt faster - it
doesn't. It just makes being accurate harder.

Also, I just reread my comment and had to say phrases like "trigger the
sucker" are exactly why I like the name of that device so much.

