Guest
 Posted: Fri Aug 13, 2026 10:27 am Post subject: Pre-conditioning & Rel Test |
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| Hello,
Please help me with the following questions: 1) Do I have to bake the pre-conditioned part before starting the reliability stress to get the moisture out? The parts were already baked as part of the pre-conditioning. I am asking after the pre-conditioned just before putting into the reliability stress. Let's say for MSL-2 or below packages. 2) Do I have to maintain the MSL level during qual read-points since the parts may sit for few days or even weeks for electrical test? Or even for transportation from one location to another to take the read-point? Please help me. Thanks, Guest |
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Guest
| Posted: Fri Aug 13, 2026 9:38 pm Post subject: |
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| No need to bake parts before rel test. Jst make sure they're precon'ed correctly. Bake then soak then IR shock. After this, package inspection, e-test, SAM. Good units after precon can go to rel stress test.
On Q#2, what do you mean by 'maintain MSL level'? For some rel tests like burn-in, there's a window to test the parts after the stress. Pls explain what you mean by your question. Paps |
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Guest
| Posted: Sat Aug 14, 2026 3:54 am Post subject: Pre-conditioning & Rel test |
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| Hi Paps,
Thanks for your quick reply. You said there is no need to bake the parts after pre-conditioning before putting the parts into rel stress. Is that true for let's say I start rel stress after 2 weeks of the pre-conditioning for a MSL-3 parts that has a floor life of 1 week? If the parts ( MSL-3) are not put into dry pack after pre-conditioning, and sitting on the floor more than a week still I don't have to bake before starting the rel stress. Is that right? What I meant to say by "maintaing MSL level" is dry packing. Since for a level-3 parts should not be kept in the floor more than a week, my question was whether we need to dry pack during the readpoint if there is a possibility that you may exceed the 1 week window before you get to take the readpoint. Please explain. Thanks for your help. |
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Guest
| Posted: Tue Aug 17, 2026 12:12 pm Post subject: |
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| The drypacking for SMD's is to protect them from cracking during board mounting. Precon is the rel test simulating moisture absorption of the package and board mounting. Thus, after precon, the units are assumed to pass board mounting. Rel test after precon checks the rel of the parts after they're board-mounted so there's no need for bake between precon and rel proper. However, you must test the parts immediately after precon before staging prior to rel.
Paps |
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Guest
| Posted: Tue Aug 17, 2026 1:36 pm Post subject: |
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| just a little caution: staging for too long has disadvantages: possible oxidation, corrosion, or esd failures if staging conditions are not correct. you also have time limits to test the units after rel stressing.
jf |
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