Heat guns near BGA packages

[spleenharvester]

Basically I need to replace a QFN chip, and given the solder joints are underneath, I need to use a heatgun.

The chip is about 7cm away from the Northbridge chip - an Intel HM55 so not really so much prone to failing.

1) Is this likely to comprimise the structure of the BGA package if there is nothing wrong already?

2) Should I have the heatgun directly over the BGA package once I'm done soldering the QFN chip to make sure the BGA joints are all uniform?

I see the term "light reflow" being thrown around a lot as a method of checking if a BGA is at fault, but this seems like a very shotgun approach to me, hence the above questions.

Cheers

[whaldsz]

Re: Heat guns near BGA packages

you can use kapton/aluminum tape to cover the bga chip.

[thesloc]

Re: Heat guns near BGA packages

7cm is pretty far.

As long as you don't move the board while applying heat that much, the bridge will be fine...

use good flux tho, like amtec to smooth the process.

[spleenharvester]

Re: Heat guns near BGA packages

I'm still using that horrid cheap yellow gooey flux lol. Need to bin it already, it's crap.

Cheers!

[tomodachi]

Re: Heat guns near BGA packages

Basically I need to replace a QFN chip, and given the solder joints are underneath, I need to use a heatgun.

The chip is about 7cm away from the Northbridge chip - an Intel HM55 so not really so much prone to failing.

1) Is this likely to comprimise the structure of the BGA package if there is nothing wrong already?

2) Should I have the heatgun directly over the BGA package once I'm done soldering the QFN chip to make sure the BGA joints are all uniform?

I see the term "light reflow" being thrown around a lot as a method of checking if a BGA is at fault, but this seems like a very shotgun approach to me, hence the above questions.

Cheers

7 cm is very safe distance for heatgun replacement, but if you hesitate you can use aluminium foil to protect the hm55 or others which you dont want to fry.