how to remove black glue in edges of chips in Lenovo laptops?

[ktmmotocross]

hello.
That black glue in edges of chips on Lenovo laptops always lift me pads so i stop reworking them. Is there anyway how to get rid of it gently?

[myth77]

Re: how to remove black glue in edges of chips in Lenovo laptops?

That is the exact reason why I also don't work with lenovo boards, either fixing them or using them for donors. If someone do know how to remove it he probably enjoying and keeps it to himself...There are some videos on youtube claiming they done it..but it seems fake.

[mcplslg123]

Re: how to remove black glue in edges of chips in Lenovo laptops?

I too dont work on lenovo when it comes to BGA chips with black glue.In SOC's besdies the four corners, there is glue at the centre as well making it almost impossible to desolder without ripping the pads. AS per some claims spraying WD40 spray under the chips for an hour and then heating up the chip for almost 10 mins under low temperature weakens the glue.Didnt dared to do it myself.

[BalkanBoy]

Re: how to remove black glue in edges of chips in Lenovo laptops?

Best method I found so far is pure mechanical.
Before lifting chip press it few times on every single corner to be sure everything is melted, balls will run away under the chip and glue will also be kinda softer, don't know why. Then lift it with precision razor spatula. Do it gently on every corner while still on infrared ofc. With that method I tend to lift only unused pads.

Also when you clean board or chip, use heatgun and same spatula you used before, don't use soldering iron and wick until you get rid of black glue.

Btw, I haven't seen glue in the middle of the chip, don't know how would they put it there in the 1st place.