0

Soldering iron and tip for MSOP-8
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Soldering iron and tip for MSOP-8

by elepton on Mon Jun 09, 2014 10:23 pm

I have an IC in a MSOP-8 package and would like to solder them to the SMT breakout board for MSOP-8 ( https://www.adafruit.com/products/1212 ). I haven't done any SMD soldering yet and am having some difficult choosing the right equipment.

Which soldering iron would be good for this? Is the adjustable 30W 110V soldering iron ( https://www.adafruit.com/products/180 ) with the included tip suitable for MSOP-8? If not, which iron and tip would be suitable?
elepton
 
Posts: 2
Joined: Mon Jun 09, 2014 9:18 pm

Re: Soldering iron and tip for MSOP-8

by adafruit_support_mike on Thu Jun 12, 2014 12:57 am

SMT soldering is a lot more forgiving than you'd think. You can blob the solder on with just about anything, then pull off the excess with some flux and a bit of solder wick.

Start by putting a dab of solder on one of the corner pads, out at the end farthest from the chip. Position the chip on the pads, then heat the blob of solder and push it along the pad until it touches the chip's pin, then pull the tip of the iron away again. Capillary action will pull enough solder into the space between the pin and pad to make a good joint, and will pull any excess away with your iron on the back-stroke.

When you have a single corner tacked down, double-check the alignment of the pins on the pads. When you're satisfied that things are in the right place, tack the opposite corner using the same push-and-pull technique.

Having two pins tacked down holds the chip in place, but you want at least one more redundant connection before you go wild with the solder. Do the other two corners the same way.

Once you're sure at least two connections will remain fixed no matter what you do, you can be less careful. Push-pull the remaining pins on each side, or just run a blob of solder along the pins with the tip of your iron. Don't worry about solder bridges between the pins, because those can be fixed.

When all the pins have solder, dip a piece of solder wick in flux and make things pretty. Rest the wick on the PCB and press the tip of your iron to it about 1/8" back from the end. The copper will carry enough heat to the tips of the wires to melt solder without any trouble.

Treat the end of the solder wick as your tool. All the iron is doing at this point is providing heat. Bring the end of the wick up against the edge of any solder you want to remove, and let capillary action do the rest. Ideally, you'll get a thin film of solder flowing across the surface of the PCB and into the wick. With a little practice you should be able to float solder out of a joint a couple millimeters away from the actual end of the wick.

If the wick starts getting too full of solder to pull effectively, stroke the tip of your iron back along the wick to pull some of the captured solder farther along the braid. Eventually you'll have to cut some of the end off the wick, but try to leave at least 1/4" of tinned copper when you do. It's easier to pull solder along tinned wire than along bare copper.

When you've taken all the solder you want, pull the solder wick back away from the joint, off the pad and onto the soldermask.

Use plenty of flux with the solder wick. It keeps the solder flowing freely, which in turn makes the wick work.

adafruit_support_mike
 
Posts: 58856
Joined: Thu Feb 11, 2010 2:51 pm

Re: Soldering iron and tip for MSOP-8

by elepton on Thu Jun 12, 2014 8:56 am

Thanks for guiding me here. It is comforting to know that SMT soldering shouldn't be as difficult and risky as I was imagining.

So I am interested in the adjustable 30W 110V soldering iron and I have some questions:
- how do I set the temperature? The dial for the temperature doesn't specify the temperature, so I guess I can't know what temperature the iron is set at?
- does it have an feedback loop for the tip temperature?
- is this compatible with the Hakko Soldering Tip T18-S4?
- by when can I expect this to be back in stock?

It would be great if you could also sell a soldering iron in which the temperature can be specified instead of just being controlled without any reference.
elepton
 
Posts: 2
Joined: Mon Jun 09, 2014 9:18 pm

Re: Soldering iron and tip for MSOP-8

by adafruit_support_bill on Thu Jun 12, 2014 9:47 am

The 30W iron has a basic uncalibrated thermostatic control. I'd start with about 3/4 full setting (higher for lead-free) and adjust up or down as needed. These do not take Hakko tips. But XYtronic tips are available from various suppliers (I believe Newark carries them).

It would be great if you could also sell a soldering iron in which the temperature can be specified instead of just being controlled without any reference.

We have a very nice one here: https://www.adafruit.com/product/1204

Image

adafruit_support_bill
 
Posts: 74337
Joined: Sat Feb 07, 2009 10:11 am

Please be positive and constructive with your questions and comments.