Lpc2000

> -----Original Message-----
> From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On Behalf
> Of Tom Walsh
> Sent: Monday, January 30, 2006 9:31 PM
> To: lpc2000@yahoogroups.com
> Subject: Re: [lpc2000] Philips LPC3180 - BGA loading Qs
> I'd be intereested in that answer myself.  I've had excellent results
> using a quartz 1500W toaster oven + mylar stencils for the LPC2xxx
> processors and other fine pitch packages.  I'm not sure how successful I
> could be with BGA though.  From what I hear, placement of the device is
> very critical and difficult to do.  Aside from that, I suspect (nobody
> will confirm this) that a hot "gas" is needed to push heat under the
> carrier.
> 
>  From what I've been told, large scale operations use a hot nitrogen gas
> to reflow such boards.  I know of the hot air unit you are referring
> to.  AFAIK, those units are pushing 700..900F hot air flow.
> Temperatures not possible in a quartz (IR) oven.

See full text below..

I use a hot air re-work machine and it does a great job.  The great things
about BGA's are they are self centering.  They can be off pad up to 60% and
when the balls flow they will pull the package into proper alignment.   For
a big production run you want to go to a place that does IR re-flow, but for
the qnt we do here our hot air machine work nicely.  It's not all that
hard!!!

Greg Deuerling
Fermi National Accelerator Laboratory
Feynman Computing Center, Room 370, MS 368
P.O.Box 500 Batavia, IL 60510
(630)840-4629     FAX  (630)840-8208
Electronic Systems Engineering Group
Work: egads@...


> -----Original Message-----
> From: lpc2000@yahoogroups.com [mailto:lpc2000@yahoogroups.com] On Behalf
> Of Tom Walsh
> Sent: Monday, January 30, 2006 9:31 PM
> To: lpc2000@yahoogroups.com
> Subject: Re: [lpc2000] Philips LPC3180 - BGA loading Qs
> 
> David Hawkins wrote:
> 
> >Ok, so it seems I'm not the only one concerned with BGA
> >prototyping or 'hobbiest' use of such devices.
> >
> >What kind of expense have people experienced for board
> >manufacturing?
> >
> >I have used subcontractors to load boards with *LOTS* of
> >BGA devices, and if I recall correctly, there was a $3k
> >NRE charge to setup the reflow machines. We had a bad
> >FPGA on one board, and that same company was able to
> >remove and replace the BGA using a hot air gun. A
> >pretty impressive feat - given that there were lots of
> >FPGAs around the one they removed (it was a correlator
> >board)
> >
> >http://www.ovro.caltech.edu/~dwh/correlator
> >
> >How about the guys reading this list that have played with
> >homemade reflow machines based on quartz ovens - any attempts
> >at loading BGA devices? Any success?
> >
> >
> >
> I'd be intereested in that answer myself.  I've had excellent results
> using a quartz 1500W toaster oven + mylar stencils for the LPC2xxx
> processors and other fine pitch packages.  I'm not sure how successful I
> could be with BGA though.  From what I hear, placement of the device is
> very critical and difficult to do.  Aside from that, I suspect (nobody
> will confirm this) that a hot "gas" is needed to push heat under the
> carrier.
> 
>  From what I've been told, large scale operations use a hot nitrogen gas
> to reflow such boards.  I know of the hot air unit you are referring
> to.  AFAIK, those units are pushing 700..900F hot air flow.
> Temperatures not possible in a quartz (IR) oven.
> 
> TomW
> 
> 
> >Dave
> >
> >
> >
> >
> >Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
> >
> >
> 
> 
> --
> Tom Walsh - WN3L - Embedded Systems Consultant
> http://openhardware.net, http://cyberiansoftware.com
> "Windows? No thanks, I have work to do..."
> ----------------------------------------------------
> 
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> Yahoo! Groups Links
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