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| decap:epoxy [2020/02/27 20:58] – [McMaster live 2019-11-10] mcmaster | decap:epoxy [2023/09/04 07:42] – mcmaster | ||
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| ===== McMaster live 2019-11-10 ===== | ===== McMaster live 2019-11-10 ===== | ||
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| Experiments trying to decap COB while keeping PCB intact | Experiments trying to decap COB while keeping PCB intact | ||
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| TLDR best result | TLDR best result | ||
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| Above is a compromise between PP providing the best chemical resistance and silicone providing the best seal | Above is a compromise between PP providing the best chemical resistance and silicone providing the best seal | ||
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| + | Above: hardened silicone bubbles on WFNA surface | ||
| Silicone only experiment | Silicone only experiment | ||
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| Someone also suggested I should try PTFE gasket. In the past I had tried kapton which didn't work well (acid tended to wick into kapton). Maybe PTFE would repel acid better | Someone also suggested I should try PTFE gasket. In the past I had tried kapton which didn't work well (acid tended to wick into kapton). Maybe PTFE would repel acid better | ||
| + | Reference: https:// | ||
| ====== Live analysis considerations ====== | ====== Live analysis considerations ====== | ||
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| ====== Laser ====== | ====== Laser ====== | ||
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| + | TLDR: bulk material for standard packages can be removed using a fiber laser. However, a CO2 laser will not work (lower peak power => melts silica instead of ablating it). However the laser will damage the die surface if you try to go all the way to the surface (without using a special setup like FALIT). Finally, COB epoxy appears to be workable even with a CO2 laser | ||
| General results | General results | ||