Whats the best temp to reflow SMD components with a hotair station?

[culcuhain]

I just picked one up and want to practice on some dead boards and an Xbox360. Whats the best temp to reflow (C or F is fine) lead free solder and leaded solder?
Whats the best temp to remove SMD parts (lead free solder and then leaded solder)?

Any other tips or tricks? ( I saw some about preheating and also not heating at temp for too long).

Thanks!

[ocf]

Re: Whats the best temp to reflow SMD components with a hotair station?

The best way to get the feel for a hot air station is to get stuck in and use it.

Temps needed will vary from board to board, depending on its thermal mass. Larger boards can be preheated to bring their ambient temperature up, this means less direct heat to the pad/joint.

A quick google search for lead/lead free solder melting temperature will give you a rough idea of the approx temps you need.

A youtube search for "hot air soldering tutorial" or similar will give you a lot of good info

I would advise watching a few vids and then practicing on a scrap board

Start with smaller components e.g. ceramic capacitors and Resistors as these will be fairly easy to lift.

Match your nozzle size to the component being removed, large enough so the hot air stream encompasses the SMD part not so large that you are heating surrounding components. It helps to move the air stream over the component to heat all leads/pads evenly, keep the nozzle close.

If you are concerned about damaging surrounding components, mask them off with Kapton/foil or place a penny over them to sink the heat.

You will need some fine tipped tweezers to lift the component when the solder has melted.

Add some flux to the pads this always aids in a clean pull

I find the tricky bit is judging when the solder on the pads has melted, if you get the tweezers in there too early you end up sinking heat away and have to heat for longer.

Watch the pads carefully, you will get the hang of spotting when the solder on the pads has liquified.

The techniques in hot air soldering vary a lot depending on the component and its location, just a matter of exposing yourself to as much hot air work as possible to get a good overall grasp of things.

Let me know if you need any further info.

p.s. I hate writing in paragraphs

-OCF