Guy Ramsey
Senior Lab Technician / Instructor

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Ph: (610) 362-1200 x107
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Stephen R. Gregory
Sent: Monday, August 13, 2001 5:04 PM
To: [log in to unmask]
Subject: Re: [TN] 6-pin DIP Optocoupler problem...

Doug,

No, the boards won't be conformally coated...the environment is basically a
climate controlled warehouse type environment.

There's very good solder joints on the leads as they are, that's because the
exposed copper is up top on the shoulder of the lead...

For my own curiosity; I've always understood that the purpose of any sort of
surface finish on boards or components, (be it tin/lead, gold, palladium,
OSP's, etc.) is to provide something that prevents the copper from oxidizing
so you can solder to it and form your metallurgical bond...is there more to
it than that?

Do I need to remove and replace these parts now? (please, please tell me no!
As luck has it, these are auto-inserted parts and have clinched leads...)

-Steve Gregory-

Steve,
I would concur with Steve Creswick, either a molding compound misalignment
or an adhesive of some sort.

As to the exposed copper:  dunno.  The potential for corrosion is higher,
depending on what ionics they left behind under the film, and how permeable
the film is to moisture and pollutant gasses.  Will the assembly be
conformally coated for service?  If so, with what?

Doug Pauls
Rockwell Collins