SMD soldering station

[hbarki]

Hi,

Does anyone know whether a hot air "SMD rework" station can be used for soldering SMD chips (SOIC, QFP, etc)?

This is the one I am considering to buy:
http://www.amazon.com/exec/obidos/t...t_shr?_encoding=UTF8&m=AKJ57Q9VZBBO8&v=glance

I am looking for a tool that I can use to solder SMD chips with minimal risk of damaging the parts.

 

[stinius]

Hi

What about this one?

https://www.elektor.com/smt-oven.683120.lynkx

Stinius

 

[coloradosound]

I have personally never used Aoyue. MOF never even
heard of them till now. Descrip says that it is ESD safe.
I know that confirmable ESD Safe units are available
from Weller, Pace, Matcal, OK Industries (Use them all).
You'll defineately want to have a 3 wire grounded cord
and check from time to time that resistance from the
ground pin on the plug to tip is less than about 5 ohms
or so and clean tip if any higher.
Having ESD safe solder station is only good if rest of the
work area is mainted to be ESD safe as well.

 

[BrianDonegan]

I have an Aoyue 968 station. The hot air works very well. Ideally you would also have a board preheater, as it can take a while to get the board surrounding the chip warm enough to melt the solder, time which can overheat the chip itself and cook it.

That said, It is possible to do all the work with just a preheater if there are no other comps on the board yet. for removing an SMD chip from a populated board however, you generally use the heater to get the board up to say 150C, then the hot air tool locally on the chip to heat and remove/replace it (~200-220C).

They make a pretty cheap heater as well, but I do not have one to vouche for it's quality. I might get one however (http://www.amazon.com/Aoyue-853A-In...8&m=AKJ57Q9VZBBO8&s=hi&qid=1225127755&sr=1-11)

 

[hbarki]

Brian,

Are you using the Aoyue station only for rework?

What kind of reflow oven do you use to mount the op-amps on the new boards? Where did you get it?

Is it better (less risk of cooking the part) using a reflow oven as opposed to hot air station (without preheater)?

Thanks!

 

[BrianDonegan]

Yes, just for rework. I also use hot tweezers for passives and SOIC parts.

For soldering things like SOIC op-amps, I just use my regular soldering iron and .015" solder. If I have a lot of them to do, I use paste and the reflow oven.

My reflow oven is a GE toaster oven with a reflow controller I got from Silicon Horizons (Ebay). It works very well. You could easily do it without the reflow controller by using temp marking sticks (http://www.stencilsunlimited.com/product_info.php?products_id=30).

 

[benchtester]

Along time ago, I used a toaster oven to cure epoxy, but it had severe hot spots.

I added plates of 1/2" thick aluminum between the coils and the parts. This helped a lot to defuse the heat and eliminate the hot spots.

 

[hbarki]

Do you think it is possible to solder this TO263 package just by using regular soldering iron? The leads sshould not be a problem, but the heatsink needs to be soldered onto a pad on the PCB - not sure if this is doable with regular iron.

http://cache.national.com/ds/LM/LME49600.pdf

I have never soldered any SMD parts before. How do you solder SOIC onto PCB using regular iron without cooking the parts? You do it one lead at a time? Do you need to use solder flux?

Thanks

 

[BrianDonegan]

That's a good idea. I was thinking of switching to a convection oven, but I might just add a couple pieces of .090 aluminum. Hmmm.

 

[BrianDonegan]

Do you think it is possible to solder this TO263 package just by using regular soldering iron? The leads sshould not be a problem, but the heatsink needs to be soldered onto a pad on the PCB - not sure if this is doable with regular iron.

http://cache.national.com/ds/LM/LME49600.pdf

I have never soldered any SMD parts before. How do you solder SOIC onto PCB using regular iron without cooking the parts? You do it one lead at a time? Do you need to use solder flux?

Thanks

It is possible with just a soldering iron. I would use solder paste for the tab though. Just squirt some paste on from a syringe, push the part into the paste, then heat the tap with the soldering iron.

For SOIC opamps with regular solder, I melt a tiny dab of solder onto one pad, then holding the chip in place, heat just that pin with the soldering iron. that loks the chip in position. Then I go from pin to pin, heating the junction with the iron, then tapping it with solder. SOIC are generally big enough to do this cleanly. My solder is Kester no-clean (leaded). As long as your iron is not overly hot, you should be able to do it with nice clean joints. I'll see if my wife can help my take some pics of the process tonight.

 

[coloradosound]

Quote
"I have never soldered any SMD parts before. How do you solder SOIC onto PCB using regular iron"

Tack soldering. Melt some solder onto the tip. Flux up the lead/
pad areas and just touch the tip to each lead quickly. Keep it
aligned with the first few pins you tack down. If you can get
a wide tip that fits your iron that is basically as long as a side
of the chip (I know Pace, Metcal, and I think Weller) has those
wide tips for SMD). You just hold that up along the length of the
pins after you've tacked them all and reflow them in mass for
about 5 sec. or so per chip side.