safe tempratures laptop board

[learnix]

Hi when working with laptop mobo's what is the temp limit that we need to set on rework station ?

should we apply flux before heating IC's or components for a quick desolder ?

thanks in advance.

[momaka]

Re: safe tempratures laptop board

Depends what you are removing. Also, is this bottom heat or top heat? For top heat, the absolute limit is always 230C since many BGA chips will get damaged at 250C and you want to have a bit of "headroom" for error.

[learnix]

Re: safe tempratures laptop board

Thanks momaka for the reply , can you explain a bit in lay man terms .. when i use the revork station i feel it is going to effect the chips or small components near by , and that is the reason for ask this question so i dont spoil other parts + ic's which i am working on.

how can i measure 230 degree i am learning and dont have luxury of complex devices.

thanks again.

[Uranium-235]

Re: safe tempratures laptop board

I try to use foil to keep the air from the other components

[momaka]

Re: safe tempratures laptop board

I guess I am a bit late to reply, but for temperature measurement, I suggest you get a TM-902C. It's a very inexpensive temperature meter. Something like this, for example:
http://www.ebay.com/itm/TM-902C-K-Ty...item4859182937
The temperature probe it comes with is a bit thick and tends to respond a little slower to temperature changes (i.e. the board can be up to 5C to 10C higher than what the meter shows if the teperature is increasing somewhat quick). But other than that, it's a worthwhile buy. I use it quite a bit.

As for the reflow process itself, I am assuming you have a reflow machine or setup of some sort - i.e. separate bottom and top heaters and not just a heat gun. I'm not an exepert on hot air, but IIRC, with hot air, you set the air temperature around 250-350C. In any case, the point is, you don't want any component on the board to go above 230C. Don't worry about the surrounding components - they won't get damaged or fall out (if on the bottom side).

I suggest you practice removing ICs from dead board first if that's possible.