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I need to remove atmega328P from arduino board and the best tool what comes up to my mind is a hot air gun. What is the maximum temperature that atmega328P can withstand?

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    A decorating style hot air gun? No, definitely not. You need a proper reflow station, or you will end up melting everything. – Majenko Jan 31 '18 at 17:13
  • The SMD version or the DIP version? The DIP can be desoldered, one pin at a time, with e.g. a solder-sucker/solder-pump. I've desoldered SMD chips by putting the entire board into a (old) pan, an heating it on a furnace. Crude, but works when in a pinch. – Gerben Jan 31 '18 at 20:22
  • new boards are under $5, is an hour or two of time for an uncertain outcome worth it? – dandavis Jan 31 '18 at 22:13
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    This really seems like it would be more appropriate on Electrical Engineering. – Makyen Jan 31 '18 at 23:32
  • You are likely to damage the connectors and displace small surface mount components before you damage the chip. A heat gun would not be recommended if you want to preserve the board, but it could with skill be used to salvage the chip. For a DIP package you should heat from the underside, and that can be an option for surface mount as well. – Chris Stratton Feb 2 '18 at 15:45
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web search reveals the peak reflow temperature is 260°C

the chip will withstand that for 15 seconds or so

here is an example graph of a reflow oven temperature during the reflow process

enter image description here

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    This is of course a specification under which the manufacturer is willing to say the chip will work. Often for personal/experimental use things far, far worse are survivable. – Chris Stratton Feb 2 '18 at 15:49
  • @Kirill there is no practical guidance here. Oven reflow and hot air rework are very different operations and it's all but certain that anyone using a temperature controlled hot air station would set it notably higher than this implies. So it's sad to see you pick this as an answer. – Chris Stratton Feb 3 '18 at 7:17
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The idea of using a simple "heat gun" (such as this) will fail on two fronts:

  1. You can't control the temperature. It will get too hot and you will damage the chip.
  2. You can't control the hot air. It will melt all the plastic items on the board (the connectors, etc) and you'll just end up with a big blob of bubbling plastic.

You need a proper reflow station. These are to a heat gun what a soldering iron is to a blow torch. They are temperature controlled, so you can select a specific temperature (with reference to the datasheet of the component you want to (de)solder), and have interchangeable nozzles to allow you to accurately direct the heat where it is needed.

I use the (cheap) Atten 858D+.

  • Actually, you can control the temperature with either a heat gun or a blow torch, by controlling distance and time. Both have a long tradition for salvaging ICs for hobby re-use off boards to be scrapped (especially in the DIP era), but yes, damage to plastic connectors is probable, and with a torch, the PCB substrate as well. Also vile smoke. – Chris Stratton Feb 2 '18 at 15:48
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    @ChrisStratton You can't control the heat accurately. There is no feedback, other than "it feels too hot" - and you can't really tell the difference between 200C and 400C and still keep the skin on your hand. – Majenko Feb 2 '18 at 16:17
  • Untrue. You know it's hot enough when the chip you've been lightly pulling on comes out. You also see the solder change appearance, and quickly learn other ways of judging - just as you do when using a precision hot air tool. Doing it from the reverse side of the board also simplifies things greatly, since you get the board and the pins which need to be hot, hot faster than the package. – Chris Stratton Feb 2 '18 at 16:59
  • @ChrisStratton And all the other components fall off too, or blow off because there's far too much air being blown, and the connectors all turn to syrup. While it is possible, on some boards, and with plenty of practice, to use a decorating heat gun, in general it's a really bad idea. – Majenko Feb 2 '18 at 17:02
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    @ChrisStratton You can do the same putting the board upside down in the oven and whacking the temperature right up. There is, of course, a higher chance you will kill the chip by using such crude tools as these. – Majenko Feb 2 '18 at 17:08
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The ATMega328P comes in 2 packages. DIP(Dual Inline Package) and SMD(Surface Mount Device)

The Hot Air Gun method is only best applicable to the SMD version. I would recommend you to not focus on what temperature the board can withstand, but try to practice on the hot air soldering techniques.

First try to practice removing SMD components on a separate PCB so you can be familiar with the hand movements and the techniques in safely removing SMD components. When you are familiar enough with the hand movements and techniques, then that is the best time to work on your Arduino Board.

After doing this you should be able to remove and SMD components from any type of circuit boards.

PS. Be sure to use a lot of soldering paste when using hotair reflow ;)

  • Actually, in some ways a heat gun is more applicable to a DIP, and that's one of the few cases I might use one rather than a precision hot air tool. The cost of likely damage to the rest of the board. – Chris Stratton Feb 2 '18 at 15:46
  • Thats correct. if the DIP is soldered on the board and has many more than 4pins, then the heat gun will come in handy. Still each person has its own way/learned technique by practice to remove components using different tools :) – EngrAbbas Feb 2 '18 at 16:56

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