Broken solder joints

[rpayne88]

So for the last month and a half, the audio jack on my laptop has constantly broken its solder joints. I've disassembled my laptop at least three times and re-soldered the joints to the board. About two weeks after doing this, the joints break again. What am I doing wrong here?

[Camacha]

Probably nothing: the original connection could be through hole, dip soldered or fastened in another hard to reproduce way. Solder on its own is not very resilient. One way to divert forces is to use hot glue to fixate the part and take the load as much as possible. Not a neat pretty fix, but easy and typically reliable. If done right, you should not see anything when the laptop is assembled.

[Tommygun]

It may not be your soldering but how much stress is being put on your audio jack or the cable going to it.

Is the cable getting pulled on or is your laptop getting knocked around with the audio cable inserted into the jack?

[Camacha]

It may not be your soldering but how much stress is being put on your audio jack or the cable going to it.

Is the cable getting pulled on or is your laptop getting knocked around with the audio cable inserted into the jack?

That is bound to happen, some laptops have a quick detaching power cable for a reason

[Kermunist]

As has been said, solder isn't very strong, and it might still break even if you're doing it right. That said, here's some tips on making a strong solder joint:

Make sure the solder wets both parts well. It should run all over the contacts. If you only put a little solder on, it should run around and coat the contacts, not sit in a ball where you put it. If this isn't happening:

- make sure both contacts are heated through (can be hard with big blocks of metal in plugs)

- try cleaning the contacts first or

- try using a small amount of flux to get things going. Clean any excess flux off afterwards.

A harder solder would be better, but might be difficult to get hold of and need a hotter soldering iron.

Unlike soldering a normal component, use loads of solder. Build up a big blob that completely covers both contacts and joins them together.

The solder joint should be shiny and bright when it's done. No stringy bits or points where you took the iron away from. If it goes dull then either:

- you took a long time to make the joint or

- you moved the component as the solder was cooling

But as I say, even if you do all this right, it still might not be that strong. The hot glue idea's a good one, I might use epoxy resin (because I don't have hot glue).

[Tommygun]

You can also use bus wire to repair/reenforce damaged or broken solder connections.

If gluing the audio port is not an option look into some kind of cable management item that could allow you to Velcro the audio cable to your lap top in a way that it will take the strain off the port as well as a good fitting and padded lap top case.

[EdFred]

The problem isn't with the joints. The problem is most likely due to the jack moving.

I've been in the soldering industry for 17+ years. Some alloys are more brittle than others, and will be more prone to fracture.

Edited August 30, 2014 by EdFred

[Nuke]

are you using old skool lead solder or the lead free stuff that manufacturers use. you might be creating a brittle alloy. the solution to this is to completely remove the part, clean the pads with some solder wick (do likewise for the part), flux and re solder.

flux is your friend. every soldering tutorial ive seen says you should be liberal with the flux. i find that they are right. flux helps remove oxidization and will ensure a solid joint.

is your iron clean? tip should be kept shinny. the best way to clean is is to add a bit of solder and remove the excess with a wet sponge. never shut it down without doing this and your tip will pretty much last forever. fail to do it once, and you will forever have a nasty tip. oxidized tip means oxidized joint and poor heat transfer.

if its a surface mount part then that is a whole other level of hell. i wouldn't even touch it without a hot air rework station. some solderers would say you can do it with any professional iron (not a radioshack fire starter, something with temperature control), but i have a reflow station and like to use the right tool for the job.