I need tips on soldering?

Question

If you were going to watch someone solder a circuit board or something and evaluate them, what would you look for?

Thanks everyone. I'll need to send it to a vote.

Answer 1

You would check that when they are soldering they have a correctly tinned soldering tip (ie it has some solder on it and is bright and shiny; I don't mean a huge blob just a light covering).
During soldering you would check the iron is in contact with both the pad they are soldering to and the leg of the component and that the solder is brought in from the other side and does not touch the iron. The solder is melted by the heat of the pad and the leg. You might also look for some form of heat sinking on some of the more delicate components such as transistors, voltage regulators etc.
After the soldering has been done you need to check the joint is bright and shiny and does not look like a blob. It should flow smoothly from the pad up the leg making a cone like shape. If it is a blob or is dull then the likelyhood is that the joint is dry and the electrical connection will be poor. If you are really after tidiness then you would check to see if the flux has been cleaned off the back of the board (though this is really being pedantic).
You could also check that the sponge they are using to wipe the iron tip with is moist and not dry or soaking wet. Another thing would be to ensure the legs of components have been snipped off as close to the board as possible.
Components should not be stacked on top of one another on the board nor should they go diagonally across the board. They should also be as close to the surface of the board as possible (so resistors should sit on the board for example). ICs should ideally be put in sockets and not directly soldered.
Finally wires should be short, neat, not crossing and the sheath go all the way to the ends. Overall the board should look neat and not messy.

Answer 2

Here's something to go on but, if you have to ask how to evaluate someone, I don't think that you're the right person to be performing the evaluation. There should a subject matter expert, someone with a couple years of experience in doing the job that is under evaluation.

Anyway, here's a few key points to check:

Clean, neat, tidy workstation. Proper ESD protection. The use of safety materials: protective eyewear, exhaust fans, etc...

Can the individual tell you at what temperature the iron is at and why it is at that temperature?

Can the individual tell you what the resistance is between the iron tip and ground?

Is the individual using the proper tools for the job?

As far as the workmanship goes, the solder should look very neat and clean and shiny. If the solder doesn't shine after cleaning, then there was not enough heat applied or the heat was not applied long enough. If the solder looks "wrinkled" then the part moved before solder solidified or the solder cooled too quickly.

Hope this helps. Good Luck.

Answer 3

1) make sure your soldering gun is warmed up good and the tip is clean 2) get some good soldering lead The components you are going to solder, the resistors, capacitors, IC chips etc. make sure you insert them all the in so that the component is almost touching the PCB (printed circuit board). Flip the PCB over and place the soldering gun on the end of the protruding "leg" of the component. Hold it for about a second and touch the tip of the gun with some lead. If all goes well, it should only take you about a second or so to do each connection. This is like trying to drive on the road after reading a driving manual. You wont get proficient until you try and try again. P.S: If you put too much solder, you can find what is called a "de-soldering wick". Place that on the extra solder and place the hot gun over it and the solder will melt and be absorbed by the wick. You can also find what are called "de-soldering pumps" Where you heat the extra solder, stick the nose of the pump in the solder and push a button and it will suck the extra solder back out. Good luck... and try not to burn yourself :)

Answer 4

*Always keep the tip coated with a thin layer of solder.
Use fluxes that are as mild as possible but still provide a strong solder joint.
Keep temperature as low as possible while maintaining enough temperature to quickly solder a joint (2 to 3 seconds maximum for electronic soldering).
Match the tips size to the work.
Use a tip with the shortest reach possible for maximum efficiency.
http://www.elexp.com/t_solder.htm
http://www.fixup.net/tips/soldering/index.htm
** The basic idea of soldering is to apply heat to the component lead and "the pad" (the conductive part of the circuit board around the lead). You want to heat both the lead and the pad and then apply the solder to the other side of the lead.

* As you install components to a circuit board, bend the leads slightly with needlenose pliers after you've put them through the board to hold the components in place while you solder. When you're done soldering, cut off any excess material with diagonal cutters.

* Clean the tip of your iron frequently with a wet sponge. Most soldering iron stands come with a sponge and a sponge dish.

* One of the main things you want to try and avoid are "cold joints" which are uneven and dull looking. A cold joint occurs when solder has flowed around a lead but has not made contact with it. This is because the iron is too cold or the surface of it is dirty (or both).

* The other main problem is solder bridges. This occurs when solder flows between two pads which will short out the circuit when electricity is applied to it. This is a big no-no (and what all the practicing is about).

* Use a heat sink to insulate components. The heat sink can be clipped onto the component on the top side of the circuit board while you solder the bottom side. Heat traveling up a component's lead (e.g. the pins on a computer chip) will be shunted off into the heat sink instead of the chip.

* Get a "Third Hand" if you're going to be working on circuit boards or other small components.

* Get a soldering iron with several sizes of replacable tips for different soldering applications.

Answer 5

Apply solder to the joint and not the gun.
Use flux.
More is not better. Use only enough to form that perfect fillet between the pin and the board.

Hold the iron to the joint for minimal time, then apply solder to the joint. Do not apply both simultaneously.

Clean the tip often.

Use the lowest temperature you can get away with, but not too low. The solder will not melt correctly.

If I think of more, I will post here

Answer 6

When soldering you need to be sure that you get enough solder on the circut but not too much.Make sure that your solder doesn't overlap onto another circut that it shouldn't be on.