Charles Barker@IO-US
08/28/97 01:27 PM

At a former location, we had some custom SMT hybrids made, I believe, on
silicon substrate. Leads were soldered to the substrate, which were then
attached to the board during oven reflow.  On the early parts, the leads
were attached with 63/37 alloy solder, the same alloy we were using to
attach the I.C.'s to the board.  They reflowed along with all the solder
paste too.

We had problems with the leads being under some tension while the boards
were reflowed and that caused many agravating intermittants.

We had the vendor change over to a higher temp solder for lead attachment
and those problems went away.

If you need more input, you may call me at 281-552-3328





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08/28/97 12:48 PM


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Subject:  [TECHNET] Assy:  Component Solder vs Assy Solder





Technetters,
        Currently, we are using high temp solder to attach leads on the
component body of a surface mount device.  The customer will use standard
63/37 to attach the other end of the lead to the board.  Historically, we
have
used the high temp solder to prevent reflow on the component when the board
goes through the IR oven.  The leads are attached around the edge and pinch
the board.
        Now the question for all the experts.  Does anyone see a problem
with
using the same solder for both attachments?  Or, does anyone see a problem
with a second reflow of the solder on the component?
        I hope this makes sense, and thanks for any input.
Glenn Pelkey
Quality/Reliability Engineer
Maxtek Components Corp.