Re: MAX3421E to PIC18F4550



On Jan 11, 12:16 pm, "urefowei" <urefo...@xxxxxxxxx> wrote:
We place 4 small vias to secure the pad of a 64pins QFN, then tin it
with some solder on top, before placing the chip on it.  We have a few
hundreds of them in use, and they are holding so far.  The device is
subject to around 50g on impact during field test.

whats best to use??
i mean, the PCB..
what particular PCB is best suited for our design especially dealing with
a TQFP..?

I can't say I understand the question. What types of PCB do you think
there are?

You can have a custom PWB made which will cost a few bucks, but
typically not prohibitive. You will then need to solder a TQFP, but
that can be done by hand with a moderate amount of skill. If you
don't want to pay the money for a custom PWB, you can buy adapters
that will let you solder the TQFP on it and will then fit a 0.1"
spaced perf board either for point to point wiring or wire wrap. If
the soldering is a problem, you can get people to do the soldering for
you.

The last few posts before yours were discussing soldering leadless
chips such as QFN packages. These tend to be very small pitch and
have no leads, so that it can be a bit tricky to get good solder
joints without paste, but it can be done. But a TQFP is a leaded part
which is much easier to work with.

Is this what you are asking? Am I misunderstanding your question?

Rick
.