Hot Air Reflow Problems - Aoyue 2702 A+

I have an unusual problem. I kill every memory module I try to reflow with hot air. I can remove/replace connectors, capacitors & jacks all day long without incident, but every time I try to reflow memory with my Aoyue 2702 A+, the module no longer works. I have tried every nozzle I have. I have gone though about 2 dozen memory modules (old, 32 mb). I have experimented with temperatures from 220 deg. C - 300 deg C. I have removed the chips, and added some flux to the solder pads and reflowed them. I don’t know if this is an accepted method of cleaning solder pads, but they looked great afterwards. I have just ordered some Polyimide tape, hoping that I can possibly shield delicate chips from the heat associated with hot air reflow. I think that possibly using a skillet to preheat the board might help reduce any thermal stress, and reduce the chance of delamination. I am also considering baking the next batch of old modules for a few hours at 90 to 100 F in a toaster oven to dry them out - who knows if there is any moisture in them. Any help would be appreciated, I’m running out of memory modules to kill!

Try adding low-melt solder (e.g., Lead-Tin-Bismuth or this stuff) to the pins so that it co-mixes with the existing solder. The new solder+old solder now has a much lower melting point and you should be able to remove the memory module at a much lower temperature.