reballing BGA chips

[Romano1]

Hello all, I need some tips or tricks with reballing BGA chips. The problem is that when I apply the soldering paste through the reballing grid, it goes underneath and the paste is all over the chip and no where should it be. So, I have to do it again and again till the balls look good. I do not think that all of you do this way. Would you please help ? Thanks a lot.

[Mrhazeem]

There is a totorial at www.mobile-tech.net ...

[Romano1]

Thanks it is helpful but they use already prepared soldering balls and I use soldering paste to make those balls directly on IC. Anyway I figured it already out how to to it perfectly. It works 100 % OK.

[Mrhazeem]

Could u post your experince here in this forum ...

[Romano1]

Sure. So the problem was, when I put the soldering paste over the reballing grid and then heated the rebaling grid bent over from the heat and soldering balls ran away all over the IC. Well, the trick is that I use a little piece of sticker to stick the BGA IC to the reballing grid, so when I use heat the IC bends with the reballing grid so the balls stay on place. It works perfectly for me.

[Mrhazeem]

Big Thanks 4 u