Any option must be known good before hardware is designed. I don't design
for the trash can.

Am aware of BT material option. We are currently ceramic with no problems,
with much push from high-priced-help to migrate to FR4 ' like everybody
else'. Of course there are no concrete examples of SMD in FR4 forthcoming,
but that doesn't reduce push from above. They would need a documented
disaster story to decide that they knew, all along, it was a bad idea.

Question is to actual performance of FR4 modules with dims equal to or
exceeding 2inches on one side. Any feedback of simple successes/niggling
problems?

Is 0.1millimeter/ .004inch achievable and how?

RL
----- Original Message -----
From: Earl Moon <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, January 21, 2002 5:24 AM
Subject: Re: [TN] FR4 power module SMC coplanarity


> First let me say Eric must know the lady about whom I speak. Ouch!
>
> Concerning a more vital, doubt it, issue, there is no reason to expect the
> PCB version, on whatever material, will go out of whack like a potato
chip.
> BGA's are built on BT based boards and they stay reasonably flat.
>
> You know it depends on how well the design was effected. You know -
balance,
> construction, etc.
>
> Just have to try them and see. If they do warp, what are your options?
>
> MoonMan
>
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