What are the advantages and disadvantages of using a reflow oven vs a hot air station for prototyping SMD PCB? Do you need an oven or would an air station work?
SMD, reflow or hot-air gun
pcb-assemblysurface-mount
Related Solutions
Very good idea to practice, practice, and practice some more on salvaged boards until you get competent with new tools. You didn't notice the solder had reached the molten state because there's so little of it used to solder components.
The typical lead-free solder has a melting point around 217 degrees C, so you'll have to get the leads and pads up to that temperature before trying to remove the component. The reason why you need a much higher temperature is because you want to get the solder joints to the melting point as fast as possible. If the hot-air gun is set to a much lower temperature, it'll take a longer time to reach the melting point. The longer the time to raise the temperature of the leads/pads will increase the overall temperature of the component, possibly past the point of destruction. So the technique is to heat it up fast, remove the part and hot-air gun, then put the part where it can cool off.
Now, if you're removing a part that's already fried due to some other reason, no worries then. Just don't damage the board by overheating the pads and causing them to lift off. If that happens, your headaches are just beginning on this repair.
Use a 12" x 12" ceramic floor tile. It will cost you less than one US dollar but if you want to splurge you can spend another dollar and buy some small stick on rubber feet for it.
Any ESD mat isn't necessarily going to hold up against the heat. You need a high temperature version if you're going to be using a hot-air rework station.
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Best Answer
The advantage of a reflow oven is that it evenly heats everything in a controlled and automated way. Assuming the oven is well calibrated you can precisely reproduce the manufacturers reflow profile, hopefully resulting in reliable soldering and very low probability of damage to components. The disadvantage is usually cost, and that cheap reflow oven often do not precisely track the programmed profile.
The advantage of hand reflow with hot air is that it is fast, doesn't require a reflow oven, and for prototyping can work quite well. The disadvantage is that it is hard to reflow large boards evenly, so except for very small PCBs you will probably end up applying too much heat to some areas and too little to others. Further problems occur with plastic components, which tend to be hard to reflow without melting because you don't have that fine control over temperature. For example, I would not use hot air to reflow a large 10" wide PCB with many surface mount components and plastic connectors, but I have done 1" PCB modules with hot air and found that it worked fairly well because the boards were so small I could evenly heat them.