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From: leila
To: wallyd
Subject: RE: Solder defect rate at 20mil pitch (fwd)
Date: Tuesday, January 09, 1996 10:12AM


Mr. Doeling,

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Thank you for you participation in our TechNet forum.

Leila Hady
IPC
847/509-9700 x311
[log in to unmask]


 ---------- Forwarded message ----------
Date: Thu, 4 Jan 96 18:22 CST
From: Wally Doeling (wallyd) <[log in to unmask]>
To: TechNet-request
     <[log in to unmask]>
Cc: "Wally Doeling (wallyd)" <[log in to unmask]>
Subject: RE: Solder defect rate at 20mil pitch


     A little info is as follows...

     4 years experience with 20 mil parts and 2 assembly houses
     Currently we have the following defect rates calculated by solder joint 

quantity.  Each pitch is calculated against the
     total number of solder joints produced by pitch.  (DPM)


     50 mil pitch   Supplier A.    3 PPM
               Supplier B     0.1 PPM

     20 mil pitch   Supplier A     7 PPM
               Supplier B     0.4 PPM

     Wallace Doeling
     Sequent Computer Systems
     [log in to unmask]

 ----------
From: TechNet-request
To: TechNet
Subject: Solder defect rate at 20mil pitch
Date: Wednesday, January 03, 1996 5:55PM

Here at Compumotor, we are going to be putting our first PCA with a 20 mil
pitch QFP into production in the near future.  I'd like to do some
benchmarking of  what everyone has seen as the difference in soldering
defect rates between 50mil pitch and 20mil pitch SMT components.  (Defects
here being defined as a short between pins or an open between pin and pad.)
Historical data on dpm at the solder joint level would be great, but I
realize probably not realistic to ask for.  The difference in first time
test yield of comparable boards with with and without fine pitch parts would
also be very valuable.  Thank you in advance.


Bryan Woods
Manufacturing Engineer
Parker Compumotor
Phone: (707)584-2542
FAX:   (707)584-8015
Email: [log in to unmask]