SMD Soldering

[SquishyIce]

Hey everyone,
I need some input on what type of iron I need to solder SMDs. At the moment I only have a standard iron from RadioShack that can switch between 15W and 30W. However, I have heard that irons with adjustable temperatures are far superior. I've also heard little snippets about hot air irons, but I'm very unfamiliar with these. Any links to store pages for recommended products would be greatly appreciated.

[Michael Hill]

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

[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.

[anthonyttu]

When it comes to soldering especially at the component level you get what you pay for in terms of irons. The adjustable irons are useful but doesn't mean they are good quality. In my opinion good tips are far more important especially with the small SMD components. Most of the Wellers from Frys or Digi Key can do the job, just be sure replacement tips are available. There are a few models with tips that are difficult to find. If your doing a massive amount of surface mount parts you should look in to using solder paste and a heat gun/oven (don't use your oven in the kitchen, once you use a oven for soldering you should never use it for food again).

[Michael Hill]

Originally Posted by anthonyttu

When it comes to soldering especially at the component level you get what you pay for in terms of irons. The adjustable irons are useful but doesn't mean good quality. In my opinion the tips are far more important especially with the small SMD components. Most of the Wellers from Frys or Digi Key can do the job, just be sure replacement tips are available. There are a few models with tips that are difficult to find.

Ya, this is important too. I like the wedge tips for SMD work. The conical tips they usually come with aren't usually very good. The chisel tips give you more contact with whatever you're trying to solder.

[SquishyIce]

Originally Posted by Michael Hill

Ya, this is important too. I like the wedge tips for SMD work. The conical tips they usually come with aren't usually very good. The chisel tips give you more contact with whatever you're trying to solder.

How pricey should the tips be? I just saw that the ones for the Hakko FX-888D cost around $10 or so. (2.4 mm chisel tip is $8.58)

[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.

[efoote868]

I own one of these:
http://www.amazon.com/Aoyue-968A-Dig...dp/B006FA481G/

I bought it for my senior year at Purdue, which made doing senior design much easier since I didn't have to share this with other people.

I did 90% of the surface mount soldering and debugging (there were a handful of caps and resistors that another team member did). The temperature control is really nice, the hot air is superb (had many people asking me to help with their projects since what I had was nicer than most of the equipment in the lab), the smoke absorber is a really nice feature once you get used to it (the extra hose makes the cord a little less flexible).


The smallest thing I've successfully soldered was a 10 pin QFN with a footprint of about 2mm x 2mm using a reflow technique.

I've heard toaster ovens can also work if you don't have hot air..

[anthonyttu]

Originally Posted by SquishyIce

How pricey should the tips be? I just saw that the ones for the Hakko FX-888D cost around $10 or so. (2.4 mm chisel tip is $8.58)

It depends on the name brand my Metcal uses $25-50 tips my weller at home uses $5 tips

[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.

[jvriezen]

I've never done any SMD / SMT work myself, but folks who run a local hacker space do it all the time-- and they don't use a soldering iron:

http://tymkrs.tumblr.com/post/794649...nna-solder-smt

[VacioArconte]

The way we solder our RN42s down, you probably don't need any fancy equipment. We put some double stick tape on the bottom and generously apply flux paste. This method works great for lining up but you can't be too overeager with the solder as the tape creates a small gap that can cause shorts underneath the board. The most important thing with SMD soldering is having the component lined up properly. As long as it is lined up, you shouldn't have any difficulties.

[dellagd]

Originally Posted by SquishyIce

How pricey should the tips be? I just saw that the ones for the Hakko FX-888D cost around $10 or so. (2.4 mm chisel tip is $8.58)

That is the normal cost for the genuine Hakko tips.

I actually just purchased one of these irons and let me tell you, after owning the one you said you have for years it was an absolute dream. You get fine temp control, a great iron holder, and tips that last, but the immediate difference I felt was the cord. Its extremely flexible, as opposed to the radioshack one, and will let you solder at whatever orientation you want.

Honestly I find soldering so relaxing now. Some people get a massage, I go into my basement and solder up a board...