BGA 3D inspection feedback

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Hi Everyone, we have here in our EMS supplier some finish go... - Oct 11, 2022 by KY

I might need some help to explain what I'm seeing here. The ... - Oct 15, 2022 by Auriga2001

#88434

BGA 3D inspection feedback | 11 October, 2022

Hi Everyone, we have here in our EMS supplier some finish goods that pass all our functional test but fail our final burning test. The burning test is a 30 minutes test which simulate customer use cases, during this test the product is subject to temperature increase and vibrations. In our analysis we have found that some PCBA have better pass rate at our functional test (fixture with bed of nails) when cooled down with a spray than at ambient temperature. We are suspecting soldering issue, we have performed 3D inspection and I have some concerns about the results but our supplier is denying any issue, I would like to get some of your comment about those pictures Thank you,

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Auriga2001

#88454

BGA 3D inspection feedback | 15 October, 2022

I might need some help to explain what I'm seeing here. The first 3 look like before pictures. They seem ok. The last 3 look like after pictures. It doesn't look like fracturing joints as would be a normal failure for vibration test, more like it reached close to liquidus temperature and loosened the bond, causing splash during vibration.

-or-

These are your spray cooling and room-temperature cooling batches. In that case, same concept, but different cause. It's reaching liquidus and the handling during removal is disturbing the bond.

Either way, my suggestion is the vibe temp. chamber is too hot or the manufacturer isn't using solder rated for that temperature. Are you spraying before moving or after moving?

-Also, what kind of 3D scanner are you using? We've been thinking about getting one.

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