decap:epoxy_acid
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decap:epoxy_acid [2021/12/29 20:01] – mcmaster | decap:epoxy_acid [2025/02/03 06:42] (current) – [Rosin] mcmaster | ||
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- Optional: mill out a cavity about the size of the die | - Optional: mill out a cavity about the size of the die | ||
- Place IC in petri dish on hot plate | - Place IC in petri dish on hot plate | ||
- | - Heat to 150C | + | - Heat hot plate to 100C |
- Place one drop of FNA (possibly mixed with concentrated sulfuric) on center of chip | - Place one drop of FNA (possibly mixed with concentrated sulfuric) on center of chip | ||
- Wait a few seconds | - Wait a few seconds | ||
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Low cost technique using readily available materials. | Low cost technique using readily available materials. | ||
- | Procedure | + | Sample procedure |
- Heat bath to desired temperature | - Heat bath to desired temperature | ||
- | * The solution will start forming black whisps when it reaches minimum temperature. | + | * TLDR: 200C is a good starting point |
- | - Cook until done. | + | - Cook until done |
+ | * TLDR: check every 15 minutes at 200C | ||
+ | * Time varies greatly with temperature, epoxy type, and thickness | ||
+ | * Solution opaque => difficult to monitor. You might need to pour to another container to check | ||
+ | * That said, probably on the order of 10s of minutes for 200C | ||
+ | * 350C will take seconds even for a thick chip | ||
+ | - Pour off as much acid as possible and then rinse chip in acetone | ||
Notes | Notes | ||
* Temperature | * Temperature | ||
+ | * The solution will start forming black whisps in solution when it reaches minimum temperature. | ||
* Higher temperatures make it go faster. | * Higher temperatures make it go faster. | ||
* At about 300C fumes are a huge problem but I did decap a large plastic chip in about 10 seconds | * At about 300C fumes are a huge problem but I did decap a large plastic chip in about 10 seconds | ||
* It may work best to reflux the acid as it will boil off rapid above about 275. I use a watch glass to cover the beaker which helps considerably and is easy | * It may work best to reflux the acid as it will boil off rapid above about 275. I use a watch glass to cover the beaker which helps considerably and is easy | ||
- | * Water severely reduces effectiveness. | + | * Water severely reduces effectiveness |
+ | * Use acetone instead of water if possible | ||
+ | * If a chip is inspected and washed | ||
* I put chips into a PTFE basket (drilled out smaller beaker) so that they can be quickly removed and inspected without cooling down the acid bath | * I put chips into a PTFE basket (drilled out smaller beaker) so that they can be quickly removed and inspected without cooling down the acid bath | ||
- | * As the acid concentration drops it begins to boil up. This is extremely dangerous and can lead to boiling over. Mitigation: | + | * As the acid concentration drops it begins to boil up. This is extremely dangerous and can lead to boiling over |
+ | * Ideally | ||
+ | * Using big beakers | ||
{{: | {{: | ||
* Sulphuric eats most metals, although slowly. Expect pins and such to still be in tact, but the bond wires will likely break without any support | * Sulphuric eats most metals, although slowly. Expect pins and such to still be in tact, but the bond wires will likely break without any support | ||
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- | ====== H2SO4 + FNA ====== | + | ===== H2SO4 + FNA ===== |
{{: | {{: | ||
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WARNING WARNING WARNING: this is very dangerous. | WARNING WARNING WARNING: this is very dangerous. | ||
+ | |||
+ | ===== Drain Pipe Opener ===== | ||
+ | |||
+ | Some strong drain pipe openers are essentially Piranha solutions. Based on my experiments, | ||
+ | |||
+ | That said, it's just as dangerous as concentrated sulfuric acid, so it should be treated with extreme caution and protection of PPEs. | ||
+ | |||
+ | The only downside is that it eats away metal and bonding wires. | ||
+ | |||
+ | Drop the chip in a beaker and submerge it in the solution. Heat the solution to boiling (warning: intense smoking will occur), and wait about 1.5 hours until the die is fully exposed. | ||
+ | |||
+ | My personal recommendation is the Black Swan " | ||
+ | |||
+ | {{: | ||
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====== Rosin ====== | ====== Rosin ====== | ||
+ | |||
+ | https:// | ||
+ | |||
Boil a chip for a few hours in rosin, like used for soldering. Refluxing equipment is ideal. Should eat away the casing. Might be best used with Dremeling or other techniques to remove the majority of the epoxy first. The active ingredient for this is abietic acid. | Boil a chip for a few hours in rosin, like used for soldering. Refluxing equipment is ideal. Should eat away the casing. Might be best used with Dremeling or other techniques to remove the majority of the epoxy first. The active ingredient for this is abietic acid. | ||
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There' | There' | ||
- | |||
====== References ====== | ====== References ====== | ||
* http:// | * http:// | ||
- | * CDCA: http:// | + | * CDCA: 403 errors (as of Nov 2023), archived in Wayback Machine: http:// |
+ | * Original URL: http:// | ||
decap/epoxy_acid.1640808096.txt.gz · Last modified: 2021/12/29 20:01 by mcmaster