Crack on die glassivation layer after T/C

Guest

Hi friends,

Anybody experience in Die crack after 500T/C test. Crack almost appear at die cornner. What shall we look for root cause ? Only material mismatch or else....?
Onething that I'd observed during FA is zero die adhesive bond line thinckness. Is it possible to be root cause ?

Package type is PDIP.

THANK YOU IN ADVANCE HELP
Tata

Joined: 20 Jun 2026 Posts: 76

Hi Tata,

Yes, I think you are correct to suspect your zero D/A BLT as a possible cause of the die cracks. Proper coverage and distribution of D/A material plays an important role in minimizing the stress experienced by the die. Even if you have enough D/A material, die cracking is a threat if there are voids or incomplete coverage in some areas under the die. Note that D/A voids are 'stress concentrators', i.e., they amplify the stress experienced by the die where they are located.

FARel Engr

Posted: Fri Jan 21, 2026 6:09 pm Post subject:

Thanks,, Hmmmmmmm I think we shall have a party immediaetly if we
have a chance.... //Tata

Guest

the root cause is the t/c test. t/c test is a destructive test, on which the device will eventually fail the longer it was subjected to it. Crazing or the di crack that you observed is a typical failure mechanism of device failing t/c test, specially those subjected to conditions c or d and beyond 100 cycles.

the failure analysis approach should be to know the purpose of the t/c test and to relate the defect seen into it. E.g. if you are qualifying the wire bonding and you saw crazing as failure mechanism - then it can be concluded that the qualification pass since the failure mechanism is not related to it.

However, if this is a pacakge reliability monitor and you saw crazing as a frequent failure mechanism - then you might consider improving some of the pacakge design such that you can attain 500 t/c cycles with zero or minimum failure.