Hello everybody, I have a question about hot air rework stations.

I, like everyone else, am having to deal, more and more, with surface mount devices. I have a good soldering station and I am OK with soldering SOIC package ICs with .050" pin pitch. Some future projects will require me to solder ICs with a .025" or a .o20" pin pitch.

I am looking at hot air rework stations and I want to get your input on them. I see prices that range from below $100 to almost $1000 for apparently the same function.

Here are some stations I have been looking at:

http://www.ebay.com/itm/968DB-SMD-S...173630?hash=item2eed44537e:g:8WYAAOSw9N1Vjms4

http://www.ebay.com/itm/898D-2in1-T...410106?hash=item56842821fa:g:JAgAAOSwQjNW9b~E

http://www.ebay.com/itm/Hakko-850B-...649540?hash=item25b53fd5c4:g:ttAAAOSwoydWoUwP

Could someone with hands on experience with hot air stations share their experiences and equipment inputs with me.

Yes, I have already listened to the EEVblog on this topic.

Thank you

 

I do use aoyue 852 cheap and works correct however you have to buy smd special air nozzles @5-6$ each.
It comes with 5 round ones only.
picbuster

 

I've been using this one:

https://www.amazon.com/gp/product/B004ZB9D4O/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

I don't have a whole lot of smd experience with it yet, but I've used the hot air for many other things and it works as advertised. My only complaint is the air hose and solder wires could be a little longer.

 

All my experience comes only from a training period I got on SMD. It made evident in the station used, the lack of small nozzles that could have made for a localized application of heat.

Desoldering a specific big IC meant every time, affecting several small ones around.

 

I use that 898D and think highly of it. I wouldn't use it for every day production work as it doesn't seem that durable, but for smaller projects it works quite well.

Both the conventional iron and the hot air tip are replaceable and the sub assemblies are available on EBay. I keep one of each on hand as spares.

 

I use the 898D too... Its cheap in every way BUT does the job just fine..
The first day the plastic closest to the "hot end" started to melt a bit but after that its worked just fine.. Never used the iron portion of it..

For a DIY'er its totally fine but if I had to use one day in and day out I'd spring for a "better $$" name brand one..

 

At work, I had a Hakko hot air rework station and I literally hated it. It was difficult to get the heat and the air flow correct for any part. I ended up using a Weller heat gun, like this one below:



With it I was able to solder and remove a wide variety of SMD footprints with ease. Even today, I use my trusty Weller to both remove and install all my SMD parts.

 

Interesting. No one has recommended a high dollar station. Two votes for 898D.

@ErnieM Thanks for bring up replacement parts/tips. Another factor to think about.

Thank you all for your inputs.

 

What are you looking to do ??Like are you looking to reflow small parts or big bga parts ??
For production items I would look into a DIY reflow oven which makes life really easy when set right ..

 

I am being forced to design with surface mount parts more and more. So, I need to expand my skills to deal with finer and finer pitch spacing. The chip manufacturers don't care that I am getting old and I need new tools and magnifying lens to soldering those microscopic parts. If I want to use those really cool new chips, I got to get me some more stuff, namely a hot air rework station.

Still looking for inputs..................

 

I am being forced to design with surface mount parts more and more. So, I need to expand my skills to deal with finer and finer pitch spacing. The chip manufacturers don't care that I am getting old and I need new tools and magnifying lens to soldering those microscopic parts. If I want to use those really cool new chips, I got to get me some more stuff, namely a hot air rework station.

Still looking for inputs..................

I just hate that market tendency of producing some rather important chips only in SMT versions. This makes it a lot more difficult for the semi-professional to develop circuits on his own. A few months ago I bought a syringe of bismuth-alloy solder, and found it quite hard to work with the thing. The only technique that more or less worked was pre-coating the PCB's traces with it before actually soldering the part...

 

A few months ago I bought a syringe of bismuth-alloy solder, and found it quite hard to work with the thing.

Why did you think that you needed low temp solder for SMT devices?

 

Why did you think that you needed low temp solder for SMT devices?

Because I have to work with some ADC chips that are extremely sensitive to high temperature (avobe 450°F) soldering. I know they're sensitive because I've already damaged quite a few of them

 

I don't know if it would apply here, but I saw a technique on youtube where a guy was replacing SMT transistors in a damaged amplifier and fortunately the PCB that held the multiple transistors came out as a module. He bought himself an electric skillet and warmed it then placed the PCB's on the skillet to pre-warm the PCB's. I don't remember what temp he said, but it was cooler than solder melting temp. BUT with the board already warm, he was able to use his iron to successfully mount the new transistors since it didn't take nearly as much heat energy from the iron to get things melted. Maybe something similar would help with some of these temperature sensitive components? Warm the PCB to a warm but safe temp, then since you'll have less local heat losses maybe you can use less energy (less peak temperature) to solder your parts!?

In my very limited (almost insignificant) hot air work, it seems that it's nearly impossible to not also heat the nearby components almost as much as the component you intend to heat. So if the PCB is tightly packed, it becomes a difficult situation. So if you're building PCB's with more than a couple of SMT parts, then maybe a home reflow oven would be best.

 

I recently had to replace the mini usb socket in a sat nav. and to prevent heat from affecting too many other parts, I got some cooking aluminium foil, made a cut out big enough to expose the old socket (shiny side up) and tucked down the edges, then with my hot air gun with it's smallest nozzle, removed the old socket without even melting the plastic in the old socket!

 

There are lots of hacks you can get away with for a while when soldering.

Once I reflowed an entire new build PCB by leaving it on my solid surface stove top burner.

This is not a recommended practice.

 

Don't know if you can make this idea work, but many years ago I messed with one of those Halogen Projector lamps, the kind you put over your sink or shine on a picture on a wall. The focus of the beam makes a crossing point where all the light is intensely focused. I used to use that to shrink tubing. I don't remember flowing solder with it and I don't know if the beam would be hot enough, but when I worked for MacDonald Douglas they had a high intensity lamp that was used to join solder butt splices with shrink tubing. You had to wear sunglasses but the solder would flow and the sleeve would shrink. That's where I got the idea to use a focused beam of light. The focal length (if my memory is worth anything) was about 3 inches. I DO remember the light getting hot enough that you couldn't hold it with your bare hand.

Think I'll give it another shot. Been fussing with different methods to shrink tubing. The lamp did quite well - that much I DO remember quite well.

 

Don't know if you can make this idea work, but many years ago I messed with one of those Halogen Projector lamps, the kind you put over your sink or shine on a picture on a wall. The focus of the beam makes a crossing point where all the light is intensely focused. I used to use that to shrink tubing. I don't remember flowing solder with it and I don't know if the beam would be hot enough, but when I worked for MacDonald Douglas they had a high intensity lamp that was used to join solder butt splices with shrink tubing. You had to wear sunglasses but the solder would flow and the sleeve would shrink. That's where I got the idea to use a focused beam of light. The focal length (if my memory is worth anything) was about 3 inches. I DO remember the light getting hot enough that you couldn't hold it with your bare hand.

Think I'll give it another shot. Been fussing with different methods to shrink tubing. The lamp did quite well - that much I DO remember quite well.

I've heard of 500W halogen work lights being used as a reflow "device". I've been meaning to build a "light oven" to try it out.

 

I THINK my rig was a 12 V 50 W focused beam used on a stereoscope. Used for inspecting electronics. Did that sort of work for over 30 years. Seen LOTS of "Bright" lights. Fortunately I've never been compelled to move toward the light.

˚J˚
˘

 

I have a cheapo brand "all-in-one" style air gun, soldering iron, and through-hole solder sucker. Save your beans and buy just the air gun if you can. I desoldered a ton of parts in my day using something like this (this is probably their updated model of what I used):

https://www.circuitspecialists.com/csi825a.html

I'm sure there are other models at other places for potentially cheaper. It seems to me, most of these are manufactured from the same place, just different labels and some feature changes. As I hinted before, the soldering iron on my unit is visibly poor quality and the solder sucker has yet to really ever work right. I don't remember using the vaccuum pickup tool, but it may have worked fine. I personally use a "popper" for removing IC's and a pair of tweezers for lining them up.

Just a side note, I really only use the hot air when removing and replacing a chip. When I am packing a board, I often just use drag soldering techniques, even on fairly fine pitch parts. I generally try to stay away from BGA and super fine parts if I am to build the board myself. However, sometimes you don't have a choice. Just to give you an idea, a board I have been building recently uses a LQFP64 and it is no problem to solder by hand and a little practice. Not saying to go without hot air, just realize it is not always necessary.