One of the biggest questions for newbies entering the microsoldering world is “what temperature should I set my hot air gun to in order to remove the shields from an iphone logic board?” Well, if you think about it, the melting temperature of lead-free solder is roughly 220 ºC, so you definitely need to set the temperature of your hot air gun to at least that much. Also remember that the temperature of the hot air gun is usually a lot lower the further the tip is away from the component.
With this said, I usually set my hot air gun to 400ºC+ to remove the shields off of an iphone logic board. It’s a lot faster and safer than setting the temperature to 300ºC and letting the hot air sit near the logic board for a good minute or two. With a higher setting, the solder melts a lot faster, which reduces the chances of damaging the components below. In addition, the shields are there to protect the opposite side from too much heat, so they should be able to absorb the heat produced by the hot air gun.
Although, I set my hot air gun to 400ºC, it doesn’t mean that your hot air gun follow the same rule because all hot air stations are different. Right now, I have three different hot air stations, a Quick 861DW, Aoyue 738h, and a Oki HCT-900. On my Quick 861DW, I need to pump the temperature all the way up to 475ºC for it work properly. On my Aoyue 738h, I have it set to 375ºC and it works better than the Quick 861DW. For the Oki, it doesn’t even have a temperature measurement; it just has a dial that goes up to 9. For my Oki, I normally set the temperature to around 7.
The point that I’m getting at is, there is no one correct temperature since all rework stations are not created equally. The idea with rework stations is to find a temperature that is hot enough to melt the solder, but not so hot that it melts everything else around it.
Here are some video examples: