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caps have yellow stain after wash

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#75847

caps have yellow stain after wash | 6 June, 2016

My operator applied flux gel ALPHA WS-609 on MG P/N FTH101XAP (CAP ALUM 100UF 50V 20% SMD) before aqueous washing the PCBAs. Solder paste used was ALPHA WS-820. Now the caps have yellow stains. Any solution to this is appreciated. Tks

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#75850

caps have yellow stain after wash | 7 June, 2016

wlsmt: You’ve got to help us out here:

* Why did you apply solder paste to capacitors prior to water washing the PCBA [where the caps were attached?]?

* Did you reflow the Alpha WS-609?

* How is the Alpha WS-820 involved in this?

* Talk about the yellow stains [ cap body, cap termination, body & termination, etc]

* You forgot to attach pictures. Pictures would be nice.

* What is the nature of the stain?

* Tell us about your water wash [DI water, water resistivity at the time of the incident, saponifiers, soaps, etc]

* What are the other things that you know but are not telling us?

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#75851

caps have yellow stain after wash | 7 June, 2016

Sorry davef. I was not being clear. PCBAs came out cold soldered after being reflowed the first time with ALPHA WS-820. The flux gel ALPHA WS 609 was supposed to be applied only onto the terminations of caps where ALPHA WS-820 was for a second reflow to fix the cold solder on pcbas. Flux gel might have been applied not only on terminations of caps but on bodies of caps. No photo was captured. My apologies again. Yes we reflowed the ALPHA WS-609. The nature of the stain might be the flux gel was left too long after reflowed before being washed away. We used DI water.

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#75855

caps have yellow stain after wash | 7 June, 2016

The first thing I would do is give Alpha a call and talk to their tech support about it.

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#75861

caps have yellow stain after wash | 9 June, 2016

Tks DeanM

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#75881

caps have yellow stain after wash | 15 June, 2016

Hi everyone..i am new here. I am hardware design engineer and as per my experience PCBAs came out cold soldered after being reflowed the first time with ALPHA WS-820. The flux gel ALPHA WS 609 was supposed to be applied only onto the terminations of caps where ALPHA WS-820 was for a second reflow to fix the cold solder on pcbas. Flux gel might have been applied not only on terminations of caps but on bodies of caps. No photo was captured.

http://www.7pcb.ca/

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#75894

caps have yellow stain after wash | 17 June, 2016

Tks Laynefelix

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