Working on SMD-setting the hot air station at 400 degree celsius, is that ok?

[Yamin]

Hi everyone,
I've been practicing on working on SMD component (trying on scrap boards of course). Many resources I came across online calls  to set the temperature at 350 degree celsius and the air at half. I am able to remove components on some of the boards sometimes set at those values and they are mostly on older boards, but like I said mostly its a hit and a miss. I do experiment with slightly higher temperature and different air settings. I never go above 380 degree celsius though.
Then I came across a youtube instructional video which suggest to use the temperature at 400 degree celsius. Could that be right? Would that be an ok temperature to set at especially if I'm planning to reuse the removed components? Setting my station at that temperature definitely gets the components removed very easily.
I am having particular bad luck removing DPAK packages specially the body connection. I haven't tried using 400 degree celsius on those yet. I do use RMA-223 flux.
Looking forward for your thoughts and any further tips would be greatly appreciated.

Thanks

[sirloin]

I'm also somewhat new to this hot air repair in terms of temperatures.

What I found made a huge difference is getting something like a hakko FR830. (or similar). Basically allows you to heat from the bottom of the board and make it easier and less stress than heating one small point on the board. So say you set the PCB heater to 200C or 175C, then your hot air tool doesn't need to blast as much heat onto the board to remove some of these tricky larger componenets.

For thin/small PCBs the lower temperature is fine since it isn't sucking the heat away from the component you are heating as fast.

Again, I am no expert and still struggle with this myself. My overall thinking is to reduce the max temperature and also reduce the thermal stress on the pcb/components by heating only one small point on the board.

[poot36]

Try setting the air at 6 (if your SMD rework station has a dial that goes to .  It will help heat the board faster.  I only use a lower air flow for small components when I am trying to re-install them.  I usually go for 350C for the lead based solder and 400C for the lead free stuff (or components with a large thermal mass).  I have yet to knowingly damage a component with the hot air that was not already failed or ready to fail soon.

[coromonadalix]

Really depend of the board thickness  i work mostly with 4 layers  and they have thick mass planes,   i have to push the heat to the max to get some results,   sometimes i use a preheat "bed" for the pcb, or  i do a crazy thing like using an heat gun and do circular patterns on the other side on the section i need to work, it can help a lot to remove some stubborn parts