Phospher bronze is one of the commonest metals that connector pins are
made of. However it is usually a base metal that is plated over with
tin/lead or nickel finished with gold. I have never heard of the
connector being offered unplated. Do your print notes call out a finish
over the PB? Could these have come to you from the connector vendor
unplated by mistake?
PB does not solder up very well, it usually needs some type of
preplating that will allow it to be soldered. 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wee Mei
Sent: Sunday, January 08, 2006 7:33 PM
To: [log in to unmask]
Subject: [TN] Solder Wettability Problem

Hello,

During assembly inspection, noticed that the solder joints on the 2
sided leads for Hirose connector, MQ172-3PA do not wet well. From the
datasheet, it seems to be of phospher bronze. As I am not a chemical
gal, is this the cause as we are using Sn37/Pb63 solder with liquid
flux.

Thanks in advance for your response.

Regards,
Wee Mei

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