Reflow oven for motherboard

[tim_n]

Last time I was in there was an oven by the electronics bench for reflowing

Is it big enough to fit a console mother board in?  And is anyone about this Saturday (sometime between 10-6) to give me some pointers?

[Tom Sands]

Yes it is (probably) big enough to fit an Xbox 360 motherboard in.

[tim_n]

Cheers Tom, much appreciated.  I assume it's a case of put board in, let warm up to temperature, cross fingers.

[Ten Yen]

Heya,

On Thu, Mar 10, 2016 at 02:32:25AM -0800, tim_n wrote:
> Cheers Tom, much appreciated. I assume it's a case of put board in, let
> warm up to temperature, cross fingers.
> On Thursday, 10 March 2016 10:21:01 UTC, Tom Sands wrote:
> > Yes it is (probably) big enough to fit an Xbox 360 motherboard in.

only read about this, no actual practical experience...
I believe Mentar succesfully reflowed a dead laptop motherboard (gfx chip
with the heatgun).

is the xbox360 mb single sided? if it isn't your at risk of gravity
pulling stuff off the bottom . . more commonly people use a heat gun
and improvised shielding to reflow stuff. . .

very interested in how you get along . .

--
http://tenyen.net/

[Nigel Worsley]

> Cheers Tom, much appreciated. I assume it's a case of put board in, let
> warm up to temperature, cross fingers.

More a case of wait for smoke or fire. It is likely that the PCB has
some through hole parts that were added after the surface mount
components went through reflow in the original manufacturing process.
These won't necessarily be able to tolerate the heat of reflow, and
may well melt if you try to reflow the whole board.

Nigle

[Nigel Worsley]

> is the xbox360 mb single sided? if it isn't your at risk of gravity
> pulling stuff off the bottom

Surface tension of the solder normally prevents this. During
manufacturing this won't work, so those components will have a small
spot of glue under them to keep them in place until the solder paste
melts.

Nigle

[tim_n]

We've got two PS3s - one of which was a launch model, so that should be OK.  It's the later model which has some plastic.  I assume they're about the same size, but if not, we may try a heat gun etc.  There's nothing wrong with trying, neither work!

We'll take pics.  Looks like 8 minutes @ 200'C is best.

[Martin (Crypt)]

I've managed to recover my graphics cards a few times on this.  Its pretty easy to use, the default settings have worked for me.  Just put it in, turn it on and wait really.

Just remember it does take a minute for metal to cool down after, ended up with a nasty blister on my finger once after trying to pull it out wihtout letting it cool first :(

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[tim_n]

Who doesn't fancy an imprinted circuit pattern burnt into your flesh?

[Mr Ed]

On Thursday, 10 March 2016 10:32:25 UTC, tim_n wrote:

Cheers Tom, much appreciated.  I assume it's a case of put board in, let warm up to temperature, cross fingers.

The default profile is for leaded solder. You will need to select the ROHS profile.

-Ed



 

[tim_n]

Cheers Ed, have looked at the manual... doesn't look too difficult!

[Mr Ed]

On Thursday, 10 March 2016 13:33:22 UTC, tim_n wrote:

Cheers Ed, have looked at the manual... doesn't look too difficult!

Yeah it's pretty straightforward. If you get into difficulty and want assistance, I'll probably be around on Wednesday evening.

-Ed

 

[Gavan Fantom]

On 10/03/2016 11:14, tim_n wrote:
> We've got two PS3s - one of which was a launch model, so that should
> be OK. It's the later model which has some plastic. I assume they're
> about the same size, but if not, we may try a heat gun etc. There's
> nothing wrong with trying, neither work!
>
> We'll take pics. Looks like 8 minutes @ 200'C is best.

If 200 degrees C works then either the calibration is badly off or the
motherboard was built before RoHS happened. Lead-free solder typically
melts at around 217 degrees C.

8 minutes at a temperature that is supposed to melt solder is *not* a
good idea. There's a reason why temperature profiles exist for reflow
soldering.

The key points are:

* You want to change temperature slowly enough to avoid thermal shock.
(typically heat up at no more than 3 degrees / second, cool down at no
more than 6 degrees / second)
* You want to give plenty of time for the temperature of the whole board
to rise so that the board won't act as a heat sink when you actually try
to melt the solder. (For lead-free, take it up slowly from 150 - 200
degrees over 1-2 minutes)
* You want to keep the time that the solder is molten and you're
exposing the components to extreme heat to a minimum. (Aim to hit 250
degrees for around 30 seconds, but don't allow the solder to be liquid
for more than a couple of minutes. A minute is fine.)

Obviously to do this properly you will need some sort of thermocouple
close to the board.

[tim_n]

Right, using the wonderful power of guessing, we selected option 7 (cat 7?) from the options board which took it to 200'C over 3 minutes, then dropped it down to 35'C and emitted a BEEEEEP when it was done.

The PS3 was rebuilt and works! And we've got two extra screws from the process.  Bonus.

So that's the first one fixed (it was found in the bin at the hackspace a couple of months ago), now we've got a couple more to have a play with.

On Thursday, 10 March 2016 10:11:49 UTC, tim_n wrote: