Based on a recent failure analysis I received on DOA parts, this sounds very
risky.  We saw a significant fallout of hermetically packaged filters, that
failed because plating particles inside the package, caused shorts after
they fell onto the metalized pattern on the quartz surface.  The particles
were in the 10 - 30 micron range.  Cleanliness is a paramount consideration
with these parts.  The substrates and bondwires are also extremely fragile.
I cannot speak for the electrical performance of what you're proposing, but
the handling and assembly logistics sound formidable.

Bruce Tostevin
Benchmark Electronics
Hudson, NH
> ----------
> From:         Chris Flores[SMTP:[log in to unmask]]
> Reply To:     TechNet E-Mail Forum.;Chris Flores
> Sent:         Thursday, April 08, 1999 7:04 AM
> To:   [log in to unmask]
> Subject:      [TN] Application of SAW filter chips
>
> This might sound slightly off-the-wall but I have to ask the question:
>
> Is it possible to buy SAW filter chips without the package (probably YES)
>
> Is it possible to bond them directly onto a PCB and then to glob-top them?
>
> And how would the globtop affect the performance of the device?  Or is a
> glob
> really needed?  Anything special needed for the chip-attach to the board?
>
> I would really appreciate any information members might have, as I am very
> much out of my depth with this type of device!
>
> Chris Flores
>
> ____________________________________________________________________
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