Re: BGA rework


Craig
 

For those who may not be aware. Unless you are sure that the MSL (Moisture Sensitivity Level) of the BGA is 1, make sure to bake the IC on the board at ~90c to 100c for 24 hours (or a lower temperature for longer time) before heating to solder melting temp.

The plastic absorbes moisture over time and will delaminate if the moisture is not removed. All ICs ( except MSL1) are vacuum packed by the manufacturer before shipping to the board assembly.

These are the allowed times of exposure to room atmosphere before ICs need to be baked.  All assembly facilities keep partially used reels or trays in dry storage after they have been opened.
  • MSL 6Mandatory Bake before use
  • MSL 5A24 hours
  • MSL 548 hours
  • MSL 472 hours
  • MSL 3168 hours
  • MSL 2A4 weeks
  • MSL 21 year
  • MSL 1Unlimited
You can get lucky sometimes, but if the IC is worth reballing, it is safer to bake before removing.

Phil



On Saturday, November 9, 2013 9:01 AM, Steve Wiseman wrote:
 
On 08/11/2013, David C. Partridge wrote:
> Do any list members living near to Coventry, England have BGA rework
> equipment?

Is Cambridge 'near' Coventry?
I've got a Metcal / OKI BGA-3500 like this

but have only run a few BGAs through it. Successfully, but I'm far
from expert - to the point where I'd rather you ran the job next to
me... How precious are the board / BGA?

Steve


Join TekScopes@groups.io to automatically receive all group messages.