Reflow BGA package?

D

DaveC

Guest
I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

<http://tinyurl.com/ny5p52>

Thanks,
 
"DaveC" <invalid@invalid.net> wrote in message
news:0001HW.C6A5BE1900549EFEB08A39AF@news.eternal-september.org...
I'd like to replace an old microprocessor that is a BGA package. New
they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52

Thanks,
Click to expand...
Yes you can but it costs. Once the BGA is removed, it needs to be
reballed.
Then reflowed, xrayed and inspected, and repeated if it failed
inspection.
One major hurdle is the thermal profile. Was the BGA the first part or
the last part?
Components on the bottom?
It gets really complicated, I doubt you'd find someone willing to do
this for 1 piece.

Cheers
 
On Mon, 10 Aug 2009 13:10:44 -0700, Martin Riddle wrote
(in article <h5pvbm$4an$1@news.eternal-september.org>):

It gets really complicated, I doubt you'd find someone willing to do
this for 1 piece.
Click to expand...
There is a place in Main, USA, that is reported to do this, one-off.

But I was considering doing it myself. The hot-plate or electric griddle
technique ($30 at Walmart). Googling around shows many successes. But with a
BGA I've yet to see it.
 
DaveC wrote:

I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?
Click to expand...
It is possible although it takes a lot of patience. Don't know if the
effort is worth $170 though.

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52
Click to expand...
Once we had two BGA pads swapped by mistake on the prototype board. The
tech managed to take the BGA off, fix the PCB and then put the BGA back.
That saved the board run.

VLV
 
On Mon, 10 Aug 2009 12:07:53 -0700, DaveC <invalid@invalid.net> wrote:

I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52

Thanks,
Click to expand...

Your best bet would be to find a lab that has an SMD rework station.

Sure, YOU can reflow a laptop chip, and removes it, and you can reflow
the bad chip and remove it, but re-using the replacement requires
specific steps.

Also, the rework station is ideal for the removal on the PCB you are
trying to fix, as hap-hazard reflow techniques can cause failures to
other components local to the removed part. That is why a rework station
is practically a requisite. You could call a few contract manufacturers
that do PCB assembly, and ask them what they would charge you to change
out a chip with no guarantees. Finding someone to perform that task for
less than $50 will not be easy. Also, it is all very likely RoHS, so
lead free processes have to be used, and that is an even higher temp.
 
On Mon, 10 Aug 2009 14:19:03 -0700, DaveC <invalid@invalid.net> wrote:

On Mon, 10 Aug 2009 13:10:44 -0700, Martin Riddle wrote
(in article <h5pvbm$4an$1@news.eternal-september.org>):

It gets really complicated, I doubt you'd find someone willing to do
this for 1 piece.

There is a place in Main, USA, that is reported to do this, one-off.

But I was considering doing it myself. The hot-plate or electric griddle
technique ($30 at Walmart). Googling around shows many successes. But with a
BGA I've yet to see it.
Click to expand...
You would have better success with a more focused heat source that a
griddle plate.

Particularly if there are other SMD parts surrounding it, and there no
doubt is.

You bring the whole assembly up to about 160 F. Then, you apply some
heat to the bottom, directly under the chip, to bring that part of the
board up a couple hundred more degrees, then you place the focused heat
on top over the chip, all the while preparing to grab it with good
tweezers or a four corner mechanism that you build specifically for
removing the chip.

You cannot pull the chip before all the balls reflow, and you cannot
"pull" at all really. If the temps are right, it will reflow, and you
should be able to lift it off with NO force required, and you should
never apply any either.

I would still get someone with a rework station to replace it though.

The surface has to be prepped after the old chip comes off, and other
things that require someone with experience to perform to keep from
buggering up the board.

You may succeed, but the odds are below 50%, and decrease another 10%
with each additional 25 balls.

Even when done in a pro lab, it is difficult, and x-rays are required
after.
 
On Aug 10, 10:40 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
DaveC wrote:
I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

It is possible although it takes a lot of patience. Don't know if the
effort is worth $170 though.

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52

Once we had two BGA pads swapped by mistake on the prototype board. The
tech managed to take the BGA off, fix the PCB and then put the BGA back.
That saved the board run.

VLV
Click to expand...
It's a relatively straightforward procedure, given the correct
equipment. X-ray isn't *required* especially for a on-off like this.
 
On Tue, 11 Aug 2009 07:54:41 -0700 (PDT), "Man at B&Q"
<manatbandq@hotmail.com> wrote:

On Aug 10, 10:40 pm, Vladimir Vassilevsky <nos...@nowhere.com> wrote:
DaveC wrote:
I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

It is possible although it takes a lot of patience. Don't know if the
effort is worth $170 though.

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52

Once we had two BGA pads swapped by mistake on the prototype board. The
tech managed to take the BGA off, fix the PCB and then put the BGA back.
That saved the board run.

VLV

It's a relatively straightforward procedure, given the correct
equipment. X-ray isn't *required* especially for a on-off like this.
Click to expand...
It IS required if the replacement does not work.
 
On Mon, 10 Aug 2009 16:40:18 -0500, Vladimir Vassilevsky
<nospam@nowhere.com> wrote:

DaveC wrote:

I'd like to replace an old microprocessor that is a BGA package. New they are
$170-plus, but I can find old ones in laptops for almost free.

Is it possible to re-flow old BGA packages or is this not possible?

It is possible although it takes a lot of patience. Don't know if the
effort is worth $170 though.

BTW, I found this study on stencils which (I think) says they're not
necessarily all that effective:

http://tinyurl.com/ny5p52

Once we had two BGA pads swapped by mistake on the prototype board. The
tech managed to take the BGA off, fix the PCB and then put the BGA back.
That saved the board run.

VLV

Impressive tech. A full board run vs. that tech multiplied by the
Click to expand...
time required per unit. How did the costs work out? Don't forget
schedule and time to market.
 
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