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Soldering Issue in Sensor component

Views: 417

#84042

Soldering Issue in Sensor component | 27 December, 2019

Dear Team,

We are facing open solder issue in a sensor component.

Rejection rate is 2 out of 50 components placed.

The issue is very random.

We have tried increasing the solder paste height from 5 mil to 7 mil. The issue persist still.

Different Profiles : With N2 , without N2.

1. Rts Profile. 2. RSS profile. 3. Slow ramp rate through the cycle. 4. Fast ramp rate at TAL stage.

Solder paste : OM338 - Lead free no clean , Type 4.

Nothing has helped to eliminate the issue. Anyone please suggest other things are area need to be looked upon.

i am attaching the component image.And the data sheet of the part. Please do the needful.

Regards, Ameen

Attachments:

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#84044

Soldering Issue in Sensor component | 27 December, 2019

Can you describe the failure mode of the soldering defect, i.e., is it failing to meet the height requirement for a castellated termination due to not wetting of the component terminations, or not wetting the pads sufficiently, or....?

We install a pressure sensor similar to this (8 pins, castellated terminations) and it took a profile optimized for flux retention (reduced soak temps in the rss profile) to improve it, and eventually a new paste to reduce defects to near zero.

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#84045

Soldering Issue in Sensor component | 27 December, 2019

Hi ,

Thanks...,

Its "not wetting the pads sufficiently"

We have tried with RTS , Our paste is ROL0 based chemistry.

Which solder have you changed.

Regards, Ameen

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#84046

Soldering Issue in Sensor component | 27 December, 2019

Yes we have tried with low soak with longer reflow and high peak also

low soak.. short TAL and low peak..

but were not able to eliminate the issue

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#84047

Soldering Issue in Sensor component | 27 December, 2019

We switched to a REL0 T3 paste, Amtech LF-4300. It wets the castellations more consistently.

I believe that in our case it was more of a plating wetting issue with the parts, but yours sounds more like a pcb finish or thermal issue. That larger pad is possibly a ground, maybe? Is it a bigger problem than the rest? If so could just be thermal issues associated with lots of copper to heat up.

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#84069

Soldering Issue in Sensor component | 31 December, 2019

Do you have clear picture show how it looks like solder open?

And you can run DOE with TAL and soak time and peak temperature to see which factor is key, or non of them is key then you can try add some flux to see if better before change solder paste because change solder paste is to hope it can more active.

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#84073

Soldering Issue in Sensor component | 31 December, 2019

Let's stay away from the PCB and process for a while. This component is pre-tinned. What kind of solder? How is the component stored? I bet you that you can put just flux on the board and solder this part - have you tried? I think we should understand what chemistry works best with the component? Do you have the ground pads on the board? Are you pasting the ground pads?

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#84136

Soldering Issue in Sensor component | 8 January, 2020

Hi Team,

Thanks a lot for the valuable suggestions.

Sorry was bit busy with some work.

Will considered all your suggestions. Get the required details and let you know.

Thank you once again.

Regards, Ameen

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