Removing an an  "Impossible to Remove" chip with ChipQuick - Page 1
Forum section: electronics / repair

author: bshambaugh
author_rank: Newbie
timestamp: April 18, 2019, 05:30:42 pm
content: I have a chip that looks kind of like this if removed (the center pads never had solder except for the center ones).When it is soldered on the board without the center pads soldered it looks like this.With the center pads soldered it looks like this:On one side it looks like this:One the other opposite side it looks like this:My proposed solution is to use Chipquick to lower the melting temperature of the solder so that I can suck it out with a de-soldering pump.Video:Product:https://www.amazon.com/ChipQuik-SMD1-Leaded-Temperature-Removal/dp/B07FYCDNVC

author: helius
author_rank: Super Contributor
timestamp: April 18, 2019, 06:28:33 pm
content: That GPS module is unusual because it has SMD pads which are connected to large vias on the board by plugging them with solder. This is not a standard practice because that type of connection is not reliable and difficult to inspect. I doubt you will be able to introduce a sufficient volume of ChipQuik into those vias since they are already fully plugged. If you use a vacuum desoldering tool, you may be able to remove enough solder from the vias to add ChipQuik to whatever is left.This product was sold as a kit for rocketry amateurs and advised a number of odd assembly techniques including bridging the castellations on the GPS module and the carrier board with sections of the leads of an axial resistor.

author: DaJMasta
author_rank: Super Contributor
timestamp: April 18, 2019, 06:58:11 pm
content: Why not hot air and maybe preheating? Isn't that the near-universal solution for pads under the package?

author: Rasz
author_rank: Super Contributor
timestamp: April 18, 2019, 07:31:15 pm
content: dont bother with de-soldering pumps, just hotair it off, looks like 2 minute job

author: KL27x
author_rank: Super Contributor
timestamp: April 19, 2019, 02:24:44 am
content: Depends on which parts you want to still work when you're done. The "chip," the thing on the other side, or the board. I think you can probably get 1 out of 3 with enough hot air.

author: bshambaugh
author_rank: Newbie
timestamp: April 24, 2019, 09:41:54 pm
content: After talking to the creator of the board, I hear that the corner pads do not matter.I had damaged the corner pads, so I tried to extend them with a single strand desoldering braid wire.This lifted up the board however. This could have made the through hole via to the bottom of the GPS module pad connections difficult.I filed down a razor blade and was able to fit it between the GPS module and the PCB board. I suspect that with the razor blade and a desoldering iron I may be able to push the desoldering braid out of the way.This could make the board functional. As it is, if I power it up I get a single flash on the HM-TRP module of both the green and red leds, but no following flashes. I think this is due to a short or possibly a non-existent connection to one of the bottom pads of the GPS module.http://www.hoperf.de/upload/rf_app/HM-TRP.pdf(page 7). The GPS module may not be able to send data to the HM-TRP module.

author: kosomsk
author_rank: Regular Contributor
timestamp: April 25, 2019, 04:22:13 pm
content: Your need professional diagnostics, if you need repair this module. Have you oscilloscope or another diagnostic & repair tools ?Maybe you should contact the service? How much does it cost to repair this device in your city?