reflowing a CPU- whats the best nozzle size?
Posted on 2011-04-20
Hi I am going to purchase a nozzle for my hot air reflow machine but I dont know what the best type to buy is. Does anyone have any sugestions if its best to buy one that fits directly over the CPU (the nozzle is the same size as the CPU) fo for example a 35x35mm nozzle, or if it is more efficient to use a smaller nozzle such as a 10x10mm nozzle and just keep working in circles?
I can see pros and cons to both types, as I would imagine with the larger nozzle I would guess there could be a hot spot or cold spot if heat does not come out uniformly (ex one area may be 200C and another area only 175C).
With the smaller one if you ran the hot air in circlrs all over the chip, you would not have any hot spots or cold spots (unless you did not do it long enough, or if you did it too long...then you would have issues) but with the smaller nozzle it would also be more of an "uneven" reflow. Not sure if that would have any effect on the cpu or not.