Help with desoldering - Page 1
Forum section: electronics / beginners

author: 2slow4me
author_rank: Newbie
timestamp: September 26, 2017, 02:31:58 am
content: Hey guys, this is my first post so be gentleAnyway, I have a CC3000 Click by mikroelektronika (this one:https://shop.mikroe.com/cc3000-click) which had 2 holes for header pins which i (badly) soldered as you will on the pictures i'll send. Now, i wanted to use UART to connect to the module, but after drilling my head on how to get it to work, i decided to use the standard SPI and just plug the module into the protoboard. However, those two goddamn pins are in the way. Now, i want to desolder them, but i don't want to ruin the module. I have a solder and a solder sucker (vacuum pump thingy). My question is: how to desolder those two header pins without ruining the wifi module or damaging it? And what is this gooey blackish thing near the solders, i haven't seen that in any tutorials i watched, which i assume means it's not meant to be there?Thanks a lot in advance, pics in the description

author: kalel
author_rank: Frequent Contributor
timestamp: September 26, 2017, 02:46:15 am
content: Hi and welcome. The gooey thing seems to be soldering flux that wasn't cleaned after soldering. Flux is either in the solder wire itself and/or added additionally to make soldering easier. It cleans the contacts from oxidation so metals can join better.For desoldering, you could apply a little bit of new solder to the joints (to easily melt the old solder) then try to use the vacuum pump to get the solder.I would watch some desoldering videos on Youtube first, or wait for advice from the experts here. I'm by no means one.

author: flynwill
author_rank: Regular Contributor
timestamp: September 26, 2017, 03:38:28 am
content: Are the pins still in the holes but cut off? If so your best bet is probably to try and use your iron to melt the solder and also at the same time push the pin far enough from one side such that you can grab it with your pliers or with your nippers and pull it out from the other side. Once the pin is gone use solder wick or a solder sucker to clean up the hoes.

author: Nusa
author_rank: Super Contributor
timestamp: September 26, 2017, 05:51:05 am
content: If the goal is just to make it work on a protoboard, one option is simply to cut those two pins off flush with the plastic and not bother to desolder the nubs.The soldering flux can be cleaned off with alcohol.For learning how to desolder, I suggest practicing on some junk electronics you don't care about until you know how to do it.

author: FreddyVictor
author_rank: Regular Contributor
timestamp: September 26, 2017, 06:47:49 am
content: First of all, remove the black plastic of the connector using snippers but do not cut the pins themselvesThen, add some solder to iron (to ensure good transfer of heat), hold tweezers in one hand and iron in the other, apply iron to a pin for a few seconds before quickly yanking the pin out with the tweezersclean up with IPA

author: helius
author_rank: Super Contributor
timestamp: September 26, 2017, 07:09:52 am
content: In situations where you only have 2 pins and they are pretty close together, you can apply heat to both at once and the pins will drop out. You can add some solder to bridge the pins together and hold the iron on them until the header pins fall out (if you want to encourage them out, remember they will be very hot so use tweezers or needle nose pliers not your hand!)

author: Ian.M
author_rank: Super Contributor
timestamp: September 26, 2017, 07:20:58 am
content: No yanking - that will probably rip out the plating of the through holes, and if you are unlucky rip the tracks off as well.If you heat the joints properly (with fresh solder on the iron), the pins should just slide out if you grip them near their tips with nippers. If you use pliers, without a strip of thin card folded over the pin as a thermal insulator, the large contact area will heatsink the pins too much and make them far harder to remove. It is worth trying to remove the plastic so you can desolder one pin at a time, but for only two pins, if the plastic is difficult to remove, simply use a big enough chisel or hoof bit to heat both pins simultaneously. Take care not to damage R1.N.B. a thin chisel or pointed bit simply wont be able to transfer enough heat to multiple pins quickly enough - you may get the pins out but the risk of board damage is much higher.

author: woody
author_rank: Frequent Contributor
timestamp: September 26, 2017, 07:43:05 am
content: What always helps me to remove unwilling stuff is to pre-heat the area on the PCB a bit. Use a heat gun. Heating up the copper pours helps the soldering iron a lot. Don't overdo this or you'll fry the rest of the components.Although in this instance I would go for the advice above: snip the pins off just above the board with a sharp cutter.

author: sasa
author_rank: Regular Contributor
timestamp: September 26, 2017, 12:01:36 pm
content: I would look at module datasheet and try to find soldering temperature, then try to comply that and do not overheat during desoldering. If it is hard to remove plastic I would carefully crush them in order to get more maneuvering space...But first, you may use free (?) online tech support and ask them what they recommends is the best way to accomplish complete operation safe. Images from side may also be helpful in order to see exactly where initial cut is done.It is important only to be careful and do not rush, prevent overheating module and pulling up traces...

author: NivagSwerdna
author_rank: Super Contributor
timestamp: September 26, 2017, 12:27:09 pm
content: Quote from: 2slow4me on September 26, 2017, 02:31:58 amYou ideally need a small soldering iron not the sort of thing used for plumbing but assuming you have the right equipment...Divide and conquer... cut the plastic between the pins to make them into two individual problems. Heat one end, pull on the other.Adding some solder to where you are going to de-solder is also a good idea if the thermal transfer isn't happening.Tidy up later with a solder sucker or desoldering braid.You are miles away from the other SMD components you should be OK.

author: innkeeper
author_rank: Unknown
timestamp: September 27, 2017, 01:37:04 am
content: The place to learn how to solderer is NOT on somithng you care about.find some old peace of junk to practice on. before you try it on something important.as your probably noticing, there are many methods and techniques to unsoldering something.practice is probably one of the most valuable things you can do before trying it on something you care about.take the advice here, practice on some other junk electronics then do it on the item you care about.overheatng your pcb and de-laminating the traces is what you want to avoid. Thing is, i would guess just about everyone who has done some desoldering has done that at least once. and that is how we learn.and .. trust me, this wont be your last messed up soldering job

author: KL27x
author_rank: Super Contributor
timestamp: September 27, 2017, 09:08:12 pm
content: For 2 pins, the plastic bit will be easy to slide off if you can get some flush cutters under them. For larger headers, it can be quite a pain, but it is doable if you really want to.It should be easy to get a bevel tip right between the protruding leads to melt both pads at once, though.

author: 2slow4me
author_rank: Newbie
timestamp: September 29, 2017, 03:11:47 pm
content: Thanks a lot guys, managed to do it with the help of my friend, now i'm using it in a project, stuck in a little rut, but that in another topicPics how the module looks now: