LPS33W Reflow profile unclear

SGano.1 · ‎2021-01-28

Hi.

According to the DS of the LPS33W - the Reflow profile should be according to JEDEC J-STD-020 , with no actual determination of the profile.

we had several boards assembled , and with very little force applied, the sensor disintegrated - the metal part from the plastic socket.

I suspect it might be the reflow profile that weaken the glue and caused this disintegration.

Is there a recommended profile for the LPS33W?

We have used before that the STEVAL-MKI205V1 - which is the LPS33W EVB ,

And had no such issue.

The pic below is of an actual reflow performed on the boards.

Thanks.

Eleon BORLINI · ‎2021-02-14

Hi @SGano.1 ,

sorry, a faster cooling ramp, you are right.

Although our internal qualification didn't show such behavior of LPS33W cap for standard SMT mounting, we will go deep in this topic.

Thank you for having reported your issue.

-Eleon

SGano.1 · ‎2021-03-03

Hi @Eleon BORLINI ,

We are experiencing a lot of failure rate by the LPS33W -some times the device is communicating via I2C - but the values of pressure and temperature are not Physically possible (garbage data).

after replacing the device- the data is valid.

The LPS33W seems very sensitive mechanically and we had to replace at least 8 pcs during our system's debug.

Is there a recommended method of strengthening the LPS33W so it is not damaged by any minor lateral force?

are there particular batches that are more vulnerable ?

We had no issues with the EVBs.

Please advise.

Eleon BORLINI · ‎2021-03-04

Hi @SGano.1 ,

>> Is there a recommended method of strengthening the LPS33W so it is not damaged by any minor lateral force?

You should try not to apply any side force during (or just after) the soldering process...

I have done what in my power contacting our internal pressure sensor quality team and the feedback from them is the one reported in my comments above.

The only additional thing I can ask you is the lot ID of the failing parts, so we can correlate any eventual weakness in production among the assembly lots with equal or similar ID code.

-Eleon

SGano.1 · ‎2021-03-15

Hi @Eleon BORLINI

Please refer to the attached photo of the reel.

Eleon BORLINI · ‎2021-03-15

Hi @SGano.1 ,

unfortunately this is not the bulk / lot ID, but the distributor commercial references (Farnell)...

You should check with Farnell, I believe...

-Eleon

SGano.1 · ‎2021-03-17

Hi @Eleon BORLINI

We are encountering numerous problems with the LPS33W .

Is there an FAE is Israel we can turn to regarding this device?

Eleon BORLINI · ‎2021-03-17

Hi @SGano.1 ,

I suggest you to contact a representative from your region the from the st.com contact page, to get more support and internal visibility -and eventually escalation- on this quality issue.

-Eleon