Amazingly priced hot air stations
Paul Baker
Posts: 6,351
If you don't know what a hot air station is, it is the method most professionals use to do hand surface mount soldering and desoldering (it is possible to mount BGA packages by hand). I have looked for one but couldn't find·any for less than·$300. www.sparkfun.com now carries 3 models ranging from $125 to $200. They are located in the tools section. They also have on the same page a digital caliper for $30, this is the price that most mechanical ones sell for.
One note of caution, working with hot air stations require extra attention when working with because its blowing air hot enough to instantly ignite flammable material if you get it too close, be sure to keep·paper products and solvents·a safe distance from your work area.
Post Edited (Paul Baker) : 4/21/2005 11:11:35 PM GMT
One note of caution, working with hot air stations require extra attention when working with because its blowing air hot enough to instantly ignite flammable material if you get it too close, be sure to keep·paper products and solvents·a safe distance from your work area.
Post Edited (Paul Baker) : 4/21/2005 11:11:35 PM GMT
Comments
Other than that, the heat has to be somewhat controlled as it is possible to 'over-cook' your project.
Sadly, surface mounting is one of those areas that makes me feel that once again hobby electronics is 'the incredible shrinking hobby' that will just disappear under an electron microscope one day.
OBVIOUSLY, DON'T USE THE TOASTER OVEN FOR FOOD after you have been baking electronics in it. You really don't need to consume heavy metals. Do you?
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
G. Herzog in Taiwan
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Sid Weaver
NEW! 4 MB EEPROM
http://hometown.aol.com/newzed/page4.html
·
I wouldn't feel that way, to be honest. Regular SOP packages and 0603 passives are pretty bearable to hand solder, and the advantages (especially not having to drill holes) are many. You can breadboard on half-pitch square pad board not quite as easily as plugging things into a breadboard, but still OK, especially with a bright light and magnifier. (If / when lead solder gets to be unavailable, hand soldering will be more annoying - all the alternatives I've met just don't flow nicely. Maybe we'll be using conductive glues or something...)
Other benefits are that it's easier to hold stock of surface mount passives - my entire resitor collection (24 values per decade, 100 resistors per value, from 1 ohm to 10MOhms, fits easily in a small ring binder - I remember my collection of pin-mount parts as a lot, lot bigger...)
(However, I have to admit that I got myself a nice stereo microscope / wafer prober off ebay last week - spent last night whipping the lids off CPUs for a look inside...)
Also - the pits on CDs are pretty darn small (and I haven't been able to see anything on DVDs yet), and I need a tame supplier of fuming nitric acid to get the epoxy off some other chips [noparse]:)[/noparse]
Steve
Was a cool course, but most of the equipment was too delicate for the ham-fisted guys in my class, so things broke regularly.
Anyhow, we had a carousel that you would put your ceramic die on and this arm (similar to the M&M sorter cam arm) would push your substrate across different hot plates at different temps. The idea was to have a "stablizing temperature" (can't rememer the actual name) then the "reflow temp" followed by the "cool down temp".
This was there were no sudden 'jarring' of temp...as we found some of those little surface mount resistors would 'tombstone' or stand on end when the heat was dramatically applied.
Another system we used was a long oven with a steel chainmail-like conveyor belt. Same idea of the carousel in the temp regions, but for more and bigger items.
We had a simple solder paste applier...you didn't need much...and too much just made a freakin mess!!
We had the 'silk-screen' facility too....so we could apply solder paste through a mask (was a pain to set up right...easier to pump a tiny blob on a pad...although you'd be cross eyed pretty quick!).
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
·
Steve
http://ca.geocities.com/steve.brady@rogers.com/index.html
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."
http://www.homanndesigns.com/SMDToasterOvenProject.html
http://www.circuitcellar.com/library/print/0704/Lacoste%5F168/
But reflow ovens cannot be used for touch-up work or desoldering, thats where hot air stations come into play.
Sid, I find that .5's are much easier that .85's, I think this is due to the extra thermal capacity of the larger pins. I haven't attempted .3's yet, most board manufacturers classify .3 pitch a speciallty process and hence cost considerably more.
SteveW, there is a new product supposedly coming out that is double-sided adhesive patches which are non conductive but have conductive channels in the Z-direction. The idea is you cut the patch to the size of the chip your using apply it to the board and mount the chip on top, the conductive channels create an electrical connection between the pad and the pin. The downside of this is trying to get the chip mounted correctly when you cannot see exactly where the pad is (it was designed for use in autoplacement systems). You of course can test it via continuity checks, but perhaps they will come out with clear patches to aid in the alignment.
Steve_b, the conveyor belt is typical for industry systems, they are used in all three types of commercial systems, reflow, wave, and vapor phase. I haven't seen a carousel based reflow system, but Id imagine the extra complexity is to enable an assembly line reflow system. I have seen a vaguely similar system where there was a pre-heat tray which took the entire board to just below the melting point of the solder, then the board was blasted with IR for a few seconds to melt the solder. This was to minimize thermal stresses which cause things like the tombstoning you describe.