How to Solve the Soldering Problem of HDMI Connector | Hacker News Reader

How to Solve the Soldering Problem of HDMI Connector

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3 pointsMakerfabs5 comments

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

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.

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.

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.

Yes, I agree with you. The only solution for soldering skill is -- practice more.

Manual soldering is inevitable the first step for an electronics maker’s skills.

Of course the most important thing to learn how to solder is to practice more!

That’s why need some soldering kit. And at the same time, you will learn nothing if you don’t spend time to find out the mistake you made in practice and why.

So I think soldering kit would be a good solution and you can easily get to know basic soldering skills. You can check the 5 Common Problems In Manual Soldering(https://www.makerfabs.cc/article/5-common-problems-in-pcba-m...) to start and find a way to avoid those common soldering problems.

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