Ideas on Inserting An Unsoldered IC into a Socket - Page 1
Forum section: electronics / projects

author: bostonman
author_rank: Super Contributor
timestamp: October 11, 2021, 02:34:55 am
content: Long story short, when I remove a questionable through-hole IC, I may want to replace it with a socket so I can stick in another IC and utilize the socket for future IC replacing.The problem I'm having is that when I remove a questionable IC, I use one from a donor. Both ICs have solder on the pins. Regardless of how much I try removing the solder, I still have a pin or two that doesn't fit and bends.Does anyone know of a socket or a method that will allow me to use ICs that have light solder on them?My only thought is to force the IC into a socket as much as possible, solder the pins, and then use that socket to plug into the socket soldered on the PCB.

author: ataradov
author_rank: Super Contributor
timestamp: October 11, 2021, 02:52:22 am
content: Can you show pictures of the ICs you think are as clean as possible? It is hard to judge from this description and the advice would vary.It will also depend on the socket type. Machined contacts (look like round holes) are much more demanding than regular wiper type.Solder braid can be used to remove a lot of bulk solder. It may leave the IC in a "like new" condition if you get enough experience.

author: xrunner
author_rank: Super Contributor
timestamp: October 11, 2021, 02:54:10 am
content: Quote from: ataradov on October 11, 2021, 02:52:22 amYea that's what I was thinking. Sometimes it seems like the solder wants to hang on - add flux to the pin and it will wipe off better.

author: bostonman
author_rank: Super Contributor
timestamp: October 11, 2021, 02:56:28 am
content: I don't have one at the moment as I resorted to soldering it back onto the board, but I was thinking more for future needs as I'm repairing a through-hole board.

author: bob91343
author_rank: Super Contributor
timestamp: October 11, 2021, 02:57:04 am
content: You could try filing or sanding the solder off the pins. Or solder wick.

author: bostonman
author_rank: Super Contributor
timestamp: October 11, 2021, 03:00:53 am
content: QuoteI'll try this and/or sanding. I was reluctant to use braid because of the heat. As for sanding, I feared I'd sand off the protective coating and cause corrosion.

author: james_s
author_rank: Super Contributor
timestamp: October 11, 2021, 03:30:34 am
content: I use braid dipped in a bit of extra flux for this, works great usually. I also use the cheaper style sockets instead of the machined pin variety which I normally prefer.

author: BrokenYugo
author_rank: Super Contributor
timestamp: October 11, 2021, 04:11:16 am
content: Braid used correctly (iron over braid over solder) doesn't put much heat into the part. I also add flux to my wick, even the good stuff is better soaked in liquid RA.

author: magic
author_rank: Super Contributor
timestamp: October 11, 2021, 06:10:46 am
content: Collect some junk solder (or use a fresh wire).Melt a big blob and cover it with a generous layer of flux (don't go too hot).Dip one side for a second or two.Dip the other side.Submerge in IPA for a few minutes to remove flux.Looks like new.Alternatively,Dispose of the part to a recycling company.Wait.Buy your IC back from AliExpress.

author: srb1954
author_rank: Super Contributor
timestamp: October 11, 2021, 07:45:15 am
content: Quote from: bostonman on October 11, 2021, 03:00:53 amTry scraping the remaining solder off with a scalpel blade. As long as you use light pressure the excess soft solder will be removed leaving a bright finish on the leads. If you see a copper colour after scraping you are using too much pressure.

author: jpanhalt
author_rank: Super Contributor
timestamp: October 11, 2021, 08:34:27 am
content: 1) Be sure they are clean with solder braid. You didn't mention using that.2) A ZIF socket (with lever) may work much better.

author: AndersJ
author_rank: Frequent Contributor
timestamp: October 11, 2021, 10:52:38 am
content: Solder the used IC to a component socket,such as Mouser 437-1601031600001101.Then plug the component socket with the IC into the socket on your board.

author: Psi
author_rank: Super Contributor
timestamp: October 11, 2021, 12:12:42 pm
content: +1 for solder braid, some good gel flux, and a good flat iron tip.It should remove every little bit of solder from any pad you touch it + the iron too, like water on a paper towel.Don't forget the gel flux, it's important. Very few solder braids have good flux inside them.If you're having issues with it not doing that then you probably have fake solder braid or flux.When it's working correctly it really does mop up solder instantly.

author: bostonman
author_rank: Super Contributor
timestamp: October 11, 2021, 01:05:57 pm
content: QuoteThis is one idea I had, however, it's an expensive and not practical idea.Seems flux and braid is the best method and I'll try it next time. Thanks everyone!

author: Ian.M
author_rank: Super Contributor
timestamp: October 11, 2021, 02:27:59 pm
content: If you want to socket a desoldered chip, a pin straightener*is essential to dress the pins in line after you've removed excess solder. If any are bent laterally, get them as straight as possible using miniature flat nose pliers, then re-apply the pin straightener tool, till it drops cleanly into the holes of a piece of 0.1" pitch perfboard (or veroboard, matrix board etc.).To remove excess solder, flux and braid works as suggested above. A jig to hold the chip supporting the pins may be helpful - a small rectangular block of wood with Kapton tape round the edge of it for heat resistance, and two parallel sawcuts in it for the other row of pins at 0.3" and 0.6" pitch so you can lightly clamp the chip in a soft-jaw vice, with its pins supported and the outer side of one row accessible for desoldering. If you are having problems with incomplete solder removal, finish desoldering by dragging the tip up the pin to its shoulder, preferably with the chip upside-down or tilted so the pin end is up, so any residual blob isn't on the part of the pin that goes in the socket, and while the tip's still on the shoulder apply a tiny drop of flux with a wooden toothpick to the pin so the remaining solder tinning on it smooths out.* e.g.https://www.futurlec.com/tools/icpinstraight.shtml

author: james_s
author_rank: Super Contributor
timestamp: October 11, 2021, 09:23:34 pm
content: Quote from: bostonman on October 11, 2021, 01:05:57 pmIf you set the chip on its side, you can hang the pins on a scrap of wood or a wooden chopstick or something for support, then you can push down a bit and wipe with the braid without bending the pins. A similar technique can be used to straighten bent pins.

author: IanJ
author_rank: Unknown
timestamp: October 11, 2021, 09:58:54 pm
content: Theres a few things to watch out for:Clean the pins by dragging the iron across them towards the tip. If you are not confident they are clean enough (both sides) then use braid. Hold the IC using a 3rd hand or small vice.Some sockets can feel pretty tight when trying to use a used IC, so when you align the IC over the socket and start pressing down then slightly wiggle the IC (very, very slightly!) to help nudge sticky pins into place. You can often bend pins by straight up just trying to press them in full on. Wiggle can give you more/better feel for how the insertion is going.Are you bending pins on the 2nd side going in? Sometimes if the 2nd side isn't aligned properly this can happen. Wiggle and pressing lightly on the 2nd side and you can feel if the insertion is going to plan before you press it hard fully home.If it's a big IC, then insert the IC one side at a time but not fully. Try to get one side in 50% of the way, then back and forth on each side till its all fully home. Try not to have the IC at too much of an angle.Turned pin sockets aren't the best when using used IC's, they can be tight, so you may have better luck by using a non turned pin type.Some sockets will splay apart internally when too thick a pin is inserted, the symptom will be that when you insert a brand new IC it may feel a bit looser in the socket, but its usually ok.You can help pre-form a brand new socket by inserting a brand new IC first, then removing it and THEN inserting the used IC, especially on turned pin sockets.Experience will get you there.......Ian.

author: David Hess
author_rank: Super Contributor
timestamp: October 11, 2021, 10:49:56 pm
content: I use solder braid and flux to wipe the pins making them look as good as new. I have a little vice to hold the IC package in position while I clean the pins.

author: Stray Electron
author_rank: Super Contributor
timestamp: October 12, 2021, 12:35:35 am
content: Quote from: bostonman on October 11, 2021, 02:34:55 amUsing a previously soldered IC in a socket is a really BAD idea! Sooner or later the solder will develop an oxide layer in it and that will cause on open circuit to the socket even when it's firmly plugged in. Ask me how I know!Even using a socket with an IC that has a different plating on the pins will usually fail after a while due to the electrolysis of the dissimilar metals. Either buy a clean IC or solder that one into the circuit.Or what you could do is to use a socket with say gold pins and then solder the IC into it and then plug that socket into a socket made of the same material on the board. I keep a lot of old prototyping boards around that HIGH quality gold plated wire wrap sockets on them just for such uses.FWIW as far as not being able to plug the IC into the socket, you could use a ZIF socket instead of a standard IC socket.

author: magic
author_rank: Super Contributor
timestamp: October 12, 2021, 05:43:44 am
content: New ICs are also tin plated copper