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thunder
Joined: 07 Jan 2026 Posts: 2	Posted: Fri Jan 16, 2026 1:15 am    Post subject: Can Heat During Decap Cause Die Crack?   good AM! Is heat applied during decapsulation specifically during full wet decapsulation can cause crack on die? what temp can cause it?
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FARel Engr
Joined: 20 Jun 2026 Posts: 76	Posted: Fri Jan 16, 2026 10:38 am    Post subject:   Hi Thunder, No, heat applied during full decap (as long as reasonable) can not crack a die. We sometimes use temps of up to 150C to fully decap a part with sulfuric acid. Just be careful not to exert any mechanical stresses on the unit (we just leave it at the bottom of the beaker). If the die cracks, then maybe it has some backside cracks already to begin with. FARel Engr
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thunder
Joined: 07 Jan 2026 Posts: 2	Posted: Sun Jan 18, 2026 6:57 pm    Post subject:   FARel Engr wrote: Hi Thunder, No, heat applied during full decap (as long as reasonable) can not crack a die. We sometimes use temps of up to 150C to fully decap a part with sulfuric acid. Just be careful not to exert any mechanical stresses on the unit (we just leave it at the bottom of the beaker). If the die cracks, then maybe it has some backside cracks already to begin with. FARel Engr thnx to that well at least now i will be confident to highlight die crack to process eng'g because sometimes they get back to us saying "are you sure it was not induced during decapsulation?". Another Q. There failed units on reliability test like PCT and IRR and during failure analysis found no visual anomalies on the die/package. Is it right to conclude that the failure is wafer fab/die related?
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FARel Engr
Joined: 20 Jun 2026 Posts: 76	Posted: Tue Jan 20, 2026 11:03 am    Post subject:   Thunder, see the other thread I started to answer your Q. Thanks, FARel Engr
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EE
Joined: 16 Jun 2026 Posts: 134 Location: Paranaque City, Phils.	Posted: Tue Jan 20, 2026 11:51 pm    Post subject:   Hi Thunder, I hope you don't mind that I edited the title of your posting. This is just to facilitate searches for articles. Anyway, when I was a young FA engineer (many years ago), I would do manual decap on SOIC's using fuming sulfuric acid heated to 250 deg C! My units always survived this temp. I only find a die crack if it had been there before decap (confirmed by curve tracing prior to decap). Just be sure that the sample is not mechanically stressed while doing this. Thanks and keep on posting! EE
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