Lik-Jen Wu,

In one of my former lives working as a Senior Manufacturing Engineer for a
Fortune 100 Company, I ran into the same problem... lots of shorts on PGA
packages.

We solved this problem by "rotating" the PCB 45 Degrees to the wave, thereby
increasing the effective distance pin to pin  by 41%. This can be
accomplished by either:

1: Rotate the solder pot in your machine (very difficult)

2: Buy a machine that has the pot at 45 deg (very expensive)

3: Design and build pallets to hold the board at 45 deg. (very time
consuming)

4: Buy pallets that can do this (we make them here, but I do not want to
advertise).

One caveat with using pallets is the width of your soldering machine...
these guys get pretty large.

Contact me "off-net" if you'd like to discuss this further.

Regards,

Ed Popielarski
QTA Machine
10 Mc Laren, Suite D
Irvine, Ca. USA 92618
Ph: (949)581-6601
Fx: (949)581-2448
E-Mail: [log in to unmask]
http://www.qta.net

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