Reballing HP G62 Intel ATI HD5470

[gcomputers]

Re: Reballing HP G62 Intel ATI HD5470

Btw, just checked the pictures and that is a nvidia GPU from the affected lot. You do know that reballing those is useless, right?

Yes yes, this reball it done as soon as i received Honton ,this chip is dead, I worked it to test the hotplate.

[atsio]

Re: Reballing HP G62 Intel ATI HD5470

Good job , but i give you an advice , if you look the chip after become brown because you use hot air to solder the balls to the chip, even before i used hot air , but now i use hot plate like (Honton 1212) and the solder process is more rapid and the chip remains the same without burning (green) .
Another advice not from me but from Amtech is the preheat process up to the temperature 140 grade C.

I really like Reballing ,i have suffered too much with BGA
at the beginning , i could not sleep thinking about it until just now don t have more problems with it .

I think you should reconsider switching to hot air and direct heating stencils. I found is the best and less stressful way to reball chipsets. It is the most controlled way to do a reball. I 've tried hot plates when I started reballing ages ago and I had a lot of failures due to stress to the chipsets, heating them from the wrong side and the lack of controll of the temperature on the chipset (chipsets do not have the same mass).

As for small size balls-pads, I do not think is the problem on reballing. A lot of times I use smaller balls than the ones that the stencil requires (i.e 0,45 instead of 0,5) in order to avoid problems with balls sticking to the stencil. The main problem for me is deformed boards (and even chipsets) - uneven surface- from long exposure to heat.

[rickybucalan]

Re: Reballing HP G62 Intel ATI HD5470

good job guys i learn a lot. tnx

[Th3_uN1Qu3]

Re: Reballing HP G62 Intel ATI HD5470

As for small size balls-pads, I do not think is the problem on reballing. A lot of times I use smaller balls than the ones that the stencil requires (i.e 0,45 instead of 0,5) in order to avoid problems with balls sticking to the stencil

That can be avoided by removing the stencil when the chip is still warm.

[atsio]

Re: Reballing HP G62 Intel ATI HD5470

That can be avoided by removing the stencil when the chip is still warm.

You think I am not doing that? You need brute force and probably end up with a deformed stencil (and probably destroyed chipset) if you try to remove it without softening by heat the flux.
I am talking of crappie stencils (bought from reputable chinese ebayers) which they say, for example, use 50mm balls but the 50mm ball will not go through unless you push it with force and is a tiresome job of widening the holes (hole by hole) with a needle.

[Th3_uN1Qu3]

Re: Reballing HP G62 Intel ATI HD5470

Haven't yet stumbled upon stencils with holes that are too small, maybe you got unlucky.

[ktmmotocross]

Re: Reballing HP G62 Intel ATI HD5470

i have this problem with some stencil for intel chipset from china. with another one not have that problem

[atsio]

Re: Reballing HP G62 Intel ATI HD5470

Yes, the new intel ones bought from e-best