SMD Soldering

[AustinSchuh]

I own 2 WES-51's for SMT work. I use the 0.01" conical tips. You can angle the iron and grab the side of the part with the side of the tip. Make sure to get some water-soluable flux. It makes SMT work easy and possible.

For 2 pin parts, I like using 2 irons. Tin both pads first, and then apply flux. Then, grab each side of the part with an iron, and place the part in the solder. Done! Way easier than messing around

I wouldn't do SMT work above 700* F if at all possible. The higher the temperature, the more thermal shock on the board and the higher likelihood of damaging something. I own a board warmer http://www.mcmelectronics.com/produc...XncaAmOY8P8HAQ to pre-heat the board so the localized heating requirements are much lower, reducing thermal stress and making it a lot easier to solder harder parts.

[ILAMtitan]

This one: http://www.hakko.com/english/products/hakko_fx888d.html

You can get it from Amazon, SparkFun, or Adafruit.

It has enough power to apply heat quickly and efficiently, and still maintain tip temperature. Ideally, you want to make the connection as quickly as possible so that heat isn't transferred into surrounding components. I usually solder PCBs at 750F, and haven't had any problems so long as the iron has enough heat capacity. You can easily swap the tips out on the Hakko for fine point work, or something bigger for through hole or large gauge wire. This will be the biggest difference for doing SMD work.

[ninja edit]Skip the hot air rework tools until your proficient at SMD work with the iron. Do some research so you know what a good connection looks like, and what you need to strive for. Once you have some hand on experience, you'll have a much more intuitive grasp of how the heat transfers and what would be easier with a hot air gun. [/ninja edit]

[Jared]

It'll be harder with a cheaper radio shack soldering iron, but not impossible. What package are you trying to solder? Some are easier than others.

The easiest way to do SMD soldering without great equipment (IMO), is to put a bit of solder on one pad on the PCB, then solder one pin of your component to the pad. This may take a few tries to get the component lined up. Next, put way too much solder over all the pins so that they're all shorted together but soldered to the pads underneath. Finally, reheat with your iron, and use solder wick to pull away extra solder. That's how I do it with a 15 watt soldering iron I bought for $7 from radio shack.

[Michael Hill]

The FX-888 is a tried and true iron. I like my Weller WESD-51. As long as you have something with good heat capacity and a temperature control. Good heat capacity is good for getting to packages with pads on then. Steer clear of ones that you plug in and change the tip for different temperatures. Those are pretty garbage.

[SquishyIce]

Originally Posted by Jared

It'll be harder with a cheaper radio shack soldering iron, but not impossible. What package are you trying to solder? Some are easier than others.

The easiest way to do SMD soldering without great equipment (IMO), is to put a bit of solder on one pad on the PCB, then solder one pin of your component to the pad. This may take a few tries to get the component lined up. Next, put way too much solder over all the pins so that they're all shorted together but soldered to the pads underneath. Finally, reheat with your iron, and use solder wick to pull away extra solder. That's how I do it with a 15 watt soldering iron I bought for $7 from radio shack.

I've heard about doing this, someone called it a "Smash and Grab." However, I'm not terribly confident in my skills with solder wick, I haven't even had much practice desoldering with my pump. I'll get some more experience and try that eventually.

[philso]

Originally Posted by Michael Hill

Check out this video. It's got a pretty good intro into SMD soldering: http://www.youtube.com/watch?v=b9FC9fAlfQE

Dave give a very thorough explanation of how to solder SMD components.

Originally Posted by Jared

It'll be harder with a cheaper radio shack soldering iron, but not impossible. What package are you trying to solder? Some are easier than others.

The easiest way to do SMD soldering without great equipment (IMO), is to put a bit of solder on one pad on the PCB, then solder one pin of your component to the pad. This may take a few tries to get the component lined up. Next, put way too much solder over all the pins so that they're all shorted together but soldered to the pads underneath. Finally, reheat with your iron, and use solder wick to pull away extra solder. That's how I do it with a 15 watt soldering iron I bought for $7 from radio shack.

With IC's, it works better to tack down two pins on opposite corners.

Originally Posted by ILAMtitan

This one: http://www.hakko.com/english/products/hakko_fx888d.html

You can get it from Amazon, SparkFun, or Adafruit.

It has enough power to apply heat quickly and efficiently, and still maintain tip temperature. Ideally, you want to make the connection as quickly as possible so that heat isn't transferred into surrounding components. I usually solder PCBs at 750F, and haven't had any problems so long as the iron has enough heat capacity. You can easily swap the tips out on the Hakko for fine point work, or something bigger for through hole or large gauge wire. This will be the biggest difference for doing SMD work.

[ninja edit]Skip the hot air rework tools until your proficient at SMD work with the iron. Do some research so you know what a good connection looks like, and what you need to strive for. Once you have some hand on experience, you'll have a much more intuitive grasp of how the heat transfers and what would be easier with a hot air gun. [/ninja edit]

You can also get good deals from eBay on new and used temperature controlled irons. Look for Hakko 926, 936 or 937. Make sure you are getting the handpiece as well as the base. I find the newer Hakko's we have at work a bit flimsy.

An alternative to using the wire type solder is to purchase some solder paste that is loaded into a syringe. Make sure it comes with a plunger. Some of the solder paste syringes are meant to be used with automated equipment where the solder paste is pushed out by the machine. Squeeze out a tiny drop on each pad. Place the component on top of the solder paste and press down gently. The surface tension of the paste should hold the part in place. Heat up the pin/pad with the tip of the iron to melt the paste. Clean up with isopropyl alcohol (rubbing alcohol).

If you are going to be doing a fair amount of SMD soldering, you will eventually have to remove parts for one reason or another. It is easiest to remove two terminal SMD components using two soldering irons, one on each terminal (electric chopsticks). IC's are best removed by using two irons to "blob-on" enough solder to bridge all the pins on each side (as quickly as possible) and flicking the IC off the pads.