Homemade SMD prototyping - with hot air

You must all be hobbiests, I assume? Heck, we end up with quite a bit of protowork here. I'll admit, while to our good customers we almost give it away, it can be expensive as a "one-off". But then again, if your time is worth something and you want it done well, perhaps it is cheap afterall.

Brian -

I have seen various postings about doing SMD prototyping with very fine point irons and solder wick for cleanup, but I would like to try hot air. But I don?t want to invest in a several $k professional hot air SMD rework station. I just want to stick down a few SOIC-8 packages. I occurred to me that something like a heat gun might work if the air flow rate were drastically reduced and the heating element power were controlled down to an level to produce 700 degree F air, and if a nozzle could be designed that squired out air in a little slit. In fact, forget about the heat gun. Just consider a length of nichrome wire, a controlled current, and a tiny fan. Has anyone tried to make their own SMD hot air tool for experimental use?

-Robert Scott Ypsilanti, Michigan

I think most cheap DIY setups are based on the Radio Shack desoldering iron (part 64-2060). The general approach is to remove the rubber bulb, and replace it with a source of air, such as a piece of aquarium air line tubing you can gently blow into to force air out the tip. The tip is stuffed with some fine steel wool which absorbs heat from the tip and helps heat the air moving through and out the tip to the solder surface.

This is the cheapest hot air gun I've found.

Actually I am a bit more than a hobbyist. I do embedded systems design, mostly software, and occasionally do some board design and prototype building. It would take me more time to explain to a contract assembly house such as yours what I want done than to do it myself. (Think of quantity 2 boards.) However if I ever wanted to make more than about 8 boards of the same type I would definitely consider a contract manufacturer.

After having posted the original question, I now see that I was wrong in assuming that all hot air SMD prototyping stations were in the multi $k range. I found some systems for under $300 plus a little more for optional nozzles from Xeltek. Anyone have any experience with this company?

-Robert Scott Ypsilanti, Michigan

Unless you do something really ODDBALL, a BOM and silkcreen usually suffices. I have seen designers that have ZERO documentation, in those cases we really can't help much w/o the bill getting bigger quite rapidly.

Having bought one recently, I'm a big fan of the system at

The air pre-heater makes a big difference, especially with ground planes. Works like magic on 0402's and 0.5mm leadframes alike.

Who is "we"? Yes, I've had stuff done by the biggies for what I considered cheap-money. Though I don't think they were doing me any major favors (contracted, perhaps). It was clear from the outset that they they were only going to build them in the single digets, with no repeat business.

If it's that common to find them on eBay selling for such a loss, I have to wonder why the original owners were so anxious to get rid of them.

-Robert Scott Ypsilanti, Michigan