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?

Dave
	

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..."
----------------
	

> -----Original Message-----
> From: lpc2000@lpc2... [mailto:lpc2000@lpc2...] On
Behalf
> Of Tom Walsh
> Sent: Monday, January 30, 2006 9:31 PM
> To: lpc2000@lpc2...
> 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@egad...
	> -----Original Message-----
> From: lpc2000@lpc2... [mailto:lpc2000@lpc2...] On
Behalf
> Of Tom Walsh
> Sent: Monday, January 30, 2006 9:31 PM
> To: lpc2000@lpc2...
> 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..."
> ----------------
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> 
> 
>
	

--- In lpc2000@lpc2..., Greg Deuerling <egads@f...> wrote:
> 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!!!

We used hot air blower (600W SMT rework/desodlering tools) to solder 
BGA on prototype boards but could only get 20-30% successful rate.
Difficult part would be chip blown completely out of PCB footprint.
Self-centering does not always pull the chip back to proper alignment
also.   Any special skill/experience to share??
Regards
	

----- Original Message ----- 
From: "unity0724" <unity0724@unit...>
To: <lpc2000@lpc2...>
Sent: Tuesday, January 31, 2006 1:20 PM
Subject: [lpc2000] Re: Philips LPC3180 - BGA loading Qs
	> --- In lpc2000@lpc2..., Greg Deuerling <egads@f...> wrote:
>> 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!!!
>
> We used hot air blower (600W SMT rework/desodlering tools) to solder
> BGA on prototype boards but could only get 20-30% successful rate.
> Difficult part would be chip blown completely out of PCB footprint.
> Self-centering does not always pull the chip back to proper alignment
> also.   Any special skill/experience to share??

An electrically heated skillet is supposed to be very good, although I 
haven't heard of anyone using one with BGAs. It does work OK with QFN 
packages, which are similar. I've bought a cheap toaster oven which I was 
intending to use with a controller, but the skillet is supposed to be 
better.

Leon
	

> Of unity0724
> Sent: Tuesday, January 31, 2006 7:21 AM
> To: lpc2000@lpc2...
> Subject: [lpc2000] Re: Philips LPC3180 - BGA loading Qs
> 
> --- In lpc2000@lpc2..., Greg Deuerling <egads@f...> wrote:
> > 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!!!
> 
> We used hot air blower (600W SMT rework/desodlering tools) to solder
> BGA on prototype boards but could only get 20-30% successful rate.
> Difficult part would be chip blown completely out of PCB footprint.
> Self-centering does not always pull the chip back to proper alignment
> also.   Any special skill/experience to share??
> Regards

Special skill's?  Yes, lots of practice and the temperature and timing have
to be closely controlled.  I recently mounted 40 672pin PBGA's and had a
100% success rate.  Altera and Xilinx will usually give you 10 or so dummy
packages to practice on before you try to place that $1000 FPGA the 1st time
:)

Our system heats the PCB from the top and the bottom board.  We use a three
step process:

1) Pre-heat the PCB to 200C for a minute or so.

2) Next soak the PCB to just 20-30C under where the solder starts to flow
for 2 minutes.  Most 10 to 12 layer PCB's I use 230C.

3) Next hit the PCB with enough heat to flow the solder for 10-30 seconds.
Most 10 to 12 layer PCB's I use 300C for 10 seconds.  This is the real
trick, you only want to flow the solder for a very short time or the package
will lay down too flat and short out balls.

The air speed on the above steps is pretty slow.  I've had 0402 cap's
that
were not held down by anything but solder paste and they did not blow away.

We use a Metcal/OKI BGA-3500 series re-work station.  Metcal does not make
the BGA-3500 any more, but I think the APR-5000 replaced it.

See: http://www.okinternational.com/product_advanced
	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@egad...
	

Hi, Thanks,
Tool used here is a handheld Leister CH-6056 hot-air blower/
desoldering tools (~US$400 cheap tool)  This tool is meant for
removing SMT/QFP parts and is NOT a proper BGA rework tool.  
Will try your way of pre-heating PCB and make sure solder balls do
not get "sandwiched" too much, also reducing that air-flow rate.
Regards

--- In lpc2000@lpc2..., Greg Deuerling <egads@...> wrote:
>
> 
> > Of unity0724
> > Sent: Tuesday, January 31, 2006 7:21 AM
> > To: lpc2000@lpc2...
> > Subject: [lpc2000] Re: Philips LPC3180 - BGA loading Qs
> > 
> > --- In lpc2000@lpc2..., Greg Deuerling <egads@f...> 
wrote:
> > > 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!!!
> > 
> > We used hot air blower (600W SMT rework/desodlering tools) to 
solder
> > BGA on prototype boards but could only get
20-30% successful 
rate.
> > Difficult part would be chip blown completely
out of PCB 
footprint.
> > Self-centering does not always pull the chip
back to proper 
alignment
> > also.   Any special skill/experience to
share??
> > Regards
> 
> Special skill's?  Yes, lots of practice and the temperature and 
timing have
> to be closely controlled.  I recently mounted 40
672pin PBGA's and 
had a
> 100% success rate.  Altera and Xilinx will usually
give you 10 or 
so dummy
> packages to practice on before you try to place
that $1000 FPGA 
the 1st time
> :)
> 
> Our system heats the PCB from the top and the bottom board.  We 
use a three
> step process:
> 
> 1) Pre-heat the PCB to 200C for a minute or so.
> 
> 2) Next soak the PCB to just 20-30C under where the solder starts 
to flow
> for 2 minutes.  Most 10 to 12 layer PCB's I
use 230C.
> 
> 3) Next hit the PCB with enough heat to flow the solder for 10-30 
seconds.
> Most 10 to 12 layer PCB's I use 300C for 10
seconds.  This is the 
real
> trick, you only want to flow the solder for a very
short time or 
the package
> will lay down too flat and short out balls.
> 
> The air speed on the above steps is pretty slow.  I've had 0402 
cap's that
> were not held down by anything but solder paste
and they did not 
blow away.
> 
> We use a Metcal/OKI BGA-3500 series re-work station.  Metcal does 
not make
> the BGA-3500 any more, but I think the APR-5000
replaced it.
> 
> See: http://www.okinternational.com/product_advanced
> 
> 
> 
> 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@...
>
	

Oven/Skillet might work.  But foresee hard to control timing and
temperature.  Hee, You seem like having some "weird" ideas as me of
using home appliances for prototyping...  
- fridge/oven for reliability/environmental testing
- dish washer for PCB washing.   (I'm using a tank with an aquarium
  pump for washing water-soluble flux/solder, works fine)
- Oven for removing moisture on PCB before soldering

Pls eMail me your procedure when you can get your BGA mounting
successful and thanks.   Most chips will be on BGA in future... :(
Regards

--- In lpc2000@lpc2..., "Leon Heller" <leon.heller@...> 
wrote:
>
> ----- Original Message ----- 
> From: "unity0724" <unity0724@...>
> To: <lpc2000@lpc2...>
> Sent: Tuesday, January 31, 2006 1:20 PM
> Subject: [lpc2000] Re: Philips LPC3180 - BGA loading Qs
> 
> 
> > --- In lpc2000@lpc2..., Greg Deuerling <egads@f...> 
wrote:
> >> 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!!!
> >
> > We used hot air blower (600W SMT rework/desodlering tools) to 
solder
> > BGA on prototype boards but could only get
20-30% successful 
rate.
> > Difficult part would be chip blown completely
out of PCB 
footprint.
> > Self-centering does not always pull the chip
back to proper 
alignment
> > also.   Any special skill/experience to
share??
> 
> An electrically heated skillet is supposed to be very good, 
although I 
> haven't heard of anyone using one with BGAs.
It does work OK with 
QFN 
> packages, which are similar. I've bought a
cheap toaster oven 
which I was 
> intending to use with a controller, but the
skillet is supposed to 
be 
> better.
> 
> Leon
>