"Nothing solders like solder!" An old, but true saying.
Try pretinning. If it won't pretin, it won't solder well in all likelyhood.
My experience. Ron Dieselberg

-----Original Message-----
From: Eric Christison [mailto:[log in to unmask]]
Sent: Thursday, October 21, 1999 08:36
To: [log in to unmask]
Subject: [TN] Micro BGA on Flex


I'd be interested in hearing a few opinions.

Weve built a small batch of flex PCB's populated with a micro BGA. We used
Ni/AU on the pads and got a terrible yield due to poor solder wetting.

We're having another go and this time we're thinking of trying HASL or
immersion tin instead.

Which would be better?

Thanks,



Eric Christison
Mechanical Engineer
VLSI Vision Ltd
Aviation House
31 Pinkhill
Edinburgh
EH12 7BF

Tel:    +44 (0) 131 539 8165
Fax:    +44 (0) 131 539 7141
A company of the STMicroelectronics Group

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