Re: OT Chip Quik - which one to choose
I highly endorse ChipQuick.toggle quoted messageShow quoted text
It has saved me a LOT of grief when having to remove LSIs but its a virtual necessity for removing through hole parts from 4 or more layer boards that have multiple embedded power and ground planes (also known as heat sinks). Yes, I have powered solder suckers, solder wick, hot air solder/desolder tools, etc. Those are all good tools, but there are times when only ChipQuik, or its equal, will allow non PCB destructive removal of a soldered in part.
The only thing that might be even better, on an occasion of need, than standard ChipQuik "sticks" would be a ChipQuick paste. I might be able to "paint", or extrude from a syringe, a paste onto the legs of an LSI, then bring the PCB up to reflow temp in my oven, thereby allowing the paste to flow into the existing solder and diminish its mechanical and thermal properties. The supposed advantage of this over using localized heat from a hot air gun is it should not be necessary to overheat the work area, necessitated by thermal wicking of the remainder of the PCB, and having less danger of harming nearby solder connections that don't quite get to reflow temperature. Once the board is sufficiently cool, significantly lower localized melt temperature would be required to remove the part of interest. I can see where this might be one of the very few ways to rework a high density PCB with SMD parts on both sides. (God, please save me from having to do such work on a beast like that.)
While on the topic of limiting heat wicking that can damage solders on nearby parts that are NOT targets for removal: Thermal dams made from a thick paste that has a good ability to absorb heat can help when an oven is unavailable or not practical to use, for whatever reason. I made my own thermal dam paste by taking apart a hot/cold pad, drying out the fluid (usually water) from the clay like mineral contents in the pack and replacing it with silicone plumbers grease until I had a very thick, virtually self supporting, anhydrous "goo".
FWIW: I have also packed this goo into the spaces inside packs of rechargeable batteries, which I built into a die cast aluminum box, also packed to the walls. Full depth heat removal is very important for getting the best life, not to mention safe operation, from such battery packs. Unlike thermal potting compound, my goo can be removed nondestructively.
Aural Technology, Ashland, OR
By my calculation, the dynamic range of the universe is roughly 679dB,
which is approximately 225 bits, collected at a rate 1.714287514x10^23 sps.
On 4/19/21 12:35 PM, Shirley Dulcey KE1L wrote:
What you're looking for is ChipQuik alloy. If you've never used it, the