ASSUMING YOU ARE GOING TO USE A BED OF NAILS TEST FIXTURE.
1. EACH NODE NEEDS TO BE AVAILABLE ON THE SOLDER SIDE. A GRID OF NO LESS
THAN .05".
2. ALLOW ROOM FOR EACH PIN ON THE COMPONENT SIDE TO HAVE AT LEAST ONE MICRO
VIA. I
   LIKE TO USE .03 PADS AND .02 DRILL.
GOOD LUCK
JOHN COY PLEXUS

-----Original Message-----
From: Matthew Lamkin
[mailto:[log in to unmask]]
Sent: Monday, March 12, 2001 12:21 AM
To: [log in to unmask]
Subject: [DC] Tips wanted for my first multilayer board?


Hello everyone,
 At last, my employer has decided that on my next board I can go past the
normal 2 layer restriction that
I normally have. (I've been waiting for this for years!)
The board will have amongst its components a MQFP208, and be a very tight
fit given the number of components
on it and where it is to fit (but then theyre all like that ar'nt they!).

Anyhow, the boss is letting me have... wait for it... 4 layers to use.
Now this may not be in the same league as all you guys doing 12-16 layers
etc, but I gotta start somewhere.

Where do I start?

Ok say I got the SMT components all placed on one side, are there any
suggestions or tips that you multilayer experts
can give me for designing with 4 layers?
I've got  funny feeling that I cannot get a power/groundplane on the inside.
I've been advised to steer clear of blind via's and have them all the way
through.

Are there any websites with multi layer info on?
Cheers - Matthew Lamkin.

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