Broken of flush-casted terminal - how to solder a wire on it? - Page 1
Forum section: electronics / repair

author: Bigman
author_rank: Regular Contributor
timestamp: November 29, 2015, 09:58:56 am
content: Hi, the picture below shows the back of a miniature loudspeaker from an in-ear earphone.There have been two pads for soldering electrical contacts on it. On each pad I was able to solder a wire on. But it took no 30sec. and one pad broke off.So what you see on the picture now is:left: the pad which did not broke ofright: at this place was a pad the same size as on the left side. But now, after it broke of, all what remains is a very, very, very tiny spot where the broken off pad was connected with (assumption)top: the tip of a needle, to give you an impression how small all this is.For me, it looks like the only possibility to solder anything on the tiny spot would be with a laser and a microscope (both I don't have). Any ideas, how I could solder this, with an hobbiest standard equipment (normal soldering iron)?Thanks!

author: Ian.M
author_rank: Super Contributor
timestamp: November 29, 2015, 10:15:49 am
content: That's FUBARed, unless you can manage to grind away enough of the board surface to expose slightly more of the hair-thin wire end, then epoxy a copper foil pad pre-drilled to let the wire end through so it can be soldered.Your best bet if the earpiece is worth enough not to simply scrap it, is to try to cannibalise a miniature speaker of the same dimensions and similar DC resistance out of cheap earbud headphones or similar.

author: RobertBG
author_rank: Regular Contributor
timestamp: December 09, 2015, 06:47:58 pm
content: Have you had any luck with this?You might be able to bypass the pad and solder a lead elsewhere on the wires from the voice coil but I cant see from the picture.Worse case you can probably locate a replacement speaker if you look in the right places as it's doubtful they manufacture them.Good luck

author: free_electron
author_rank: Super Contributor
timestamp: December 09, 2015, 06:52:46 pm
content: silver epoxy paint.put a dot on it. let it dry then solder a wire to it

author: Bigman
author_rank: Regular Contributor
timestamp: December 09, 2015, 06:56:42 pm
content: Quote from: free_electron on December 09, 2015, 06:52:46 pmwow that is a total new idea ... and sound's great. This is the next approach I will try.(because up to now I haven't been able to fix it. I also don't see a chance to open the housing in order to place a wire somewhere else. Tomorrow, I might upload a picture of the housing, so you will understand).

author: lowimpedance
author_rank: Super Contributor
timestamp: December 09, 2015, 10:24:05 pm
content: Quote from: Bigman on December 09, 2015, 06:56:42 pmNot sure it will take the heat, however a big enough blob might just glue the wire directly with no solder needed.

author: Brumby
author_rank: Unknown
timestamp: December 10, 2015, 03:55:16 am
content: Make sure your wires are laid out the way you want them and that you can test your efforts exactly where the speaker sits. When you have success, don't move a thing! Put a drop of hot melt glue, silicon, epoxy or something to take the mechanical stresses of wire movement away from your fragile connection - and wait until that has set firmly before doing anything else.It would be really annoying to have a successful repair fail as you refitted the speaker.