engifineer
05-07-2005, 06:19 PM
Since there are a number of electronic/electrical related mods going on, such as the gauge lighting mod, I thought I would share a little info on soldering for those who do not have much experienc soldering, especially on a PCB (printed circuit board). I hope this is useful for some. It is amazing how much easier the job is when you know a few things about the process. First big thing is to clean the connetion points... even if they just sit out a day or two! Oxidation makes it very difficult to solder. some very fine sandpaper works well for this.
1) For soldering on the PCB's, you will want a low wattage iron with a small tip. Typically someone with a lot of experience can use a higher wattage iron without damage as you will get better at making the solder joints faster. But I reccomend using a 15 - 20 watt iron for PCB work. You can get a decent iron at Radio Shack for very cheap. Try to get one with a stand and a place for a sponge ( I will explain this in a minute) . For PCB work I use a small gauge 60/40 solder. You can easily find this at radio shack. For best results with small components, use a small solder. Even better is a fluxless solder with a bottle of liquid flux, but this is harder to find and is more difficult to learn at first.
For those that plan on doing more than one soldering project!
I HIGHLY recommend getting yourself a good iron! Better irons will be temperature controlled rather than power controlled. A power controlled iron will work to provide the same amount of power to the tip at all times. The problem with this is that with different tips and different sized components you get varying levels of heat transfer, meaning the temp will fluctuate. A good temp controlled iron will keep the tip at a constant temp, so this isnt an issue.
The second benefit of a better iron is that most will be protected against ESD (electrostatic discharge), which can damage sensitive components on the board.
And the third benefit, of course, is the life of the iron. Cheaper Radio Shack irons will not last very long at all. I only mention using them because many people will buy an iron for this particular job and dont care to buy a more expensive one. But I really recommned a good iron for doing these types of projects.
I use weller temp controlled, digital readout irons. You can get one for about $120 and it is well worth it.
2) You will defintely want a set of tweezers, most of the devices on the PCB are going to be surface mount, meaning they are very small. A magnifying glass stand is also useful if you have one.
3) The sponge. An iron with a stand will come with one and have a place to hold it. If not, I reccomend a peice of sponge or a rag in some type of container. You will want to keep this wet while working. After heating up the iron, and occasionally between solder joints, whipe the iron on the sponge. This will remove small deposits and buildups on the tip. It will take only a few seconds for it to heat back up (as this drops the temp a bit). This is an important step that many miss. The small buildups not only cause poor solder joints but also interfere with heat transfer, which makes soldering more difficult.
4) After heating it up and whiping it, tin the tip with a small amount of solder. This coating of solder helps the heat transfer process.
5) Making the connections. One thing to keep in mind is that the solder will "wick" its way to the hottest point. So avoid touching the solder to the tip while trying to make a joint, it will simply flow to the tip of the iron. The idea is to make good contact with both the connection point on the board as well as the connection point on the part with the tip of the iron. This is where you can see the benefit of tinning the iron before hand, it adds surface area to transfer the heat. While touch the part and board with the iron, touch the solder to a point on the connection but do not touch it to the iron. This will ensure that it wicks across the connection point and makes a smooth connection. Once this occurs, pull the solder away and remove the iron by sliding it up and off of the connection. Do not move the part! A perfect connection , once dry, will have a concave drop of solder on it (not too much in other words) and will be shiny. A dull look to the solder means you may have moved the part while it cooled, which creates a "cold joint". These types of joints are prone to failure down the road. The entire solder process should take as little time as possible to avoid overheating (a second or two max on baord mounted devices). When having to hold the part with tweezers for the first connection, I let the solder on the tip make a temporary connection, then move to the other side of the component. This will free both hands so you can heat the joint and add solder as needed. Then return to the first connection and make it a better one.
6) Removing solder. One cheap tool to remove solder is called Solder Wick. You can also buy this at Radio Shack. Remember the "wicking" process I mentioned? This is how solder wick works. It is a braided copper material. You lay it on the solder in question, and lay the iron on top of the solder wick. The solder will flow through the braided copper towards the iron, removing it from the board.
7) Clean the board. You will see some dark spots around the joints. This is the flux in the solder. Clean this off with something like an old toothbrush. For jobs where I do a lot of soldering on a board, I actually clean the entire baord with warm water. Just make sure it is completely dry before powering it up!!! Also, if there are any motors, servos, etc you do not want to let water get into them, as it will take forever for it to dry. If you use water, use an air nozzle to blow it dry and then let it sit. For smaller jobs you can usually do it without water and be ok.
For soldering larger stuff like wiring, the same rules apply, only you will want a slightly larger iron and larger solder. Always place the iron on the opposite side of the connection than where you are touching the solder. With wiring, use heatshrink (also available at Radio Shack) rather than electrical tape to insulate the connections. Electrical tape will eventually come off. Slide the proper size heatshrink down onto one of the wires, make your solder joint, and slide it back up over the joint. Use a heat gun or lighter to heat it to the point that is shrinks down around the connection. This will leave a good and professional looking connection!
I hope this helps some people. I know I had soldered quite a bit before college, but had to take a short soldering class in college as well as a longer one at one of the jobs I had while in college, and it was amazing how much these little details helped! If I left anything out, or mispelled/misworded something.. just lemme know
:P
1) For soldering on the PCB's, you will want a low wattage iron with a small tip. Typically someone with a lot of experience can use a higher wattage iron without damage as you will get better at making the solder joints faster. But I reccomend using a 15 - 20 watt iron for PCB work. You can get a decent iron at Radio Shack for very cheap. Try to get one with a stand and a place for a sponge ( I will explain this in a minute) . For PCB work I use a small gauge 60/40 solder. You can easily find this at radio shack. For best results with small components, use a small solder. Even better is a fluxless solder with a bottle of liquid flux, but this is harder to find and is more difficult to learn at first.
For those that plan on doing more than one soldering project!
I HIGHLY recommend getting yourself a good iron! Better irons will be temperature controlled rather than power controlled. A power controlled iron will work to provide the same amount of power to the tip at all times. The problem with this is that with different tips and different sized components you get varying levels of heat transfer, meaning the temp will fluctuate. A good temp controlled iron will keep the tip at a constant temp, so this isnt an issue.
The second benefit of a better iron is that most will be protected against ESD (electrostatic discharge), which can damage sensitive components on the board.
And the third benefit, of course, is the life of the iron. Cheaper Radio Shack irons will not last very long at all. I only mention using them because many people will buy an iron for this particular job and dont care to buy a more expensive one. But I really recommned a good iron for doing these types of projects.
I use weller temp controlled, digital readout irons. You can get one for about $120 and it is well worth it.
2) You will defintely want a set of tweezers, most of the devices on the PCB are going to be surface mount, meaning they are very small. A magnifying glass stand is also useful if you have one.
3) The sponge. An iron with a stand will come with one and have a place to hold it. If not, I reccomend a peice of sponge or a rag in some type of container. You will want to keep this wet while working. After heating up the iron, and occasionally between solder joints, whipe the iron on the sponge. This will remove small deposits and buildups on the tip. It will take only a few seconds for it to heat back up (as this drops the temp a bit). This is an important step that many miss. The small buildups not only cause poor solder joints but also interfere with heat transfer, which makes soldering more difficult.
4) After heating it up and whiping it, tin the tip with a small amount of solder. This coating of solder helps the heat transfer process.
5) Making the connections. One thing to keep in mind is that the solder will "wick" its way to the hottest point. So avoid touching the solder to the tip while trying to make a joint, it will simply flow to the tip of the iron. The idea is to make good contact with both the connection point on the board as well as the connection point on the part with the tip of the iron. This is where you can see the benefit of tinning the iron before hand, it adds surface area to transfer the heat. While touch the part and board with the iron, touch the solder to a point on the connection but do not touch it to the iron. This will ensure that it wicks across the connection point and makes a smooth connection. Once this occurs, pull the solder away and remove the iron by sliding it up and off of the connection. Do not move the part! A perfect connection , once dry, will have a concave drop of solder on it (not too much in other words) and will be shiny. A dull look to the solder means you may have moved the part while it cooled, which creates a "cold joint". These types of joints are prone to failure down the road. The entire solder process should take as little time as possible to avoid overheating (a second or two max on baord mounted devices). When having to hold the part with tweezers for the first connection, I let the solder on the tip make a temporary connection, then move to the other side of the component. This will free both hands so you can heat the joint and add solder as needed. Then return to the first connection and make it a better one.
6) Removing solder. One cheap tool to remove solder is called Solder Wick. You can also buy this at Radio Shack. Remember the "wicking" process I mentioned? This is how solder wick works. It is a braided copper material. You lay it on the solder in question, and lay the iron on top of the solder wick. The solder will flow through the braided copper towards the iron, removing it from the board.
7) Clean the board. You will see some dark spots around the joints. This is the flux in the solder. Clean this off with something like an old toothbrush. For jobs where I do a lot of soldering on a board, I actually clean the entire baord with warm water. Just make sure it is completely dry before powering it up!!! Also, if there are any motors, servos, etc you do not want to let water get into them, as it will take forever for it to dry. If you use water, use an air nozzle to blow it dry and then let it sit. For smaller jobs you can usually do it without water and be ok.
For soldering larger stuff like wiring, the same rules apply, only you will want a slightly larger iron and larger solder. Always place the iron on the opposite side of the connection than where you are touching the solder. With wiring, use heatshrink (also available at Radio Shack) rather than electrical tape to insulate the connections. Electrical tape will eventually come off. Slide the proper size heatshrink down onto one of the wires, make your solder joint, and slide it back up over the joint. Use a heat gun or lighter to heat it to the point that is shrinks down around the connection. This will leave a good and professional looking connection!
I hope this helps some people. I know I had soldered quite a bit before college, but had to take a short soldering class in college as well as a longer one at one of the jobs I had while in college, and it was amazing how much these little details helped! If I left anything out, or mispelled/misworded something.. just lemme know
:P