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Post by retrobits on Jul 27, 2006 18:38:57 GMT -5
Hi, I'm getting back into hobbyist electronics, mostly because of the fun of microcontrollers. It's cool to be working with breadboards, components, etc again. I could use some advice on soldering equipment. Much of the soldering done for small hobbyist work requires caution so that you do not melt the components, insulation, etc. Can someone who does this kind of thing tell me what type of equipment you would recommend, including the iron itself, solder remover, heat sinks, etc? Or, are there good tutorial resources I could read? One of the projects I want to work on will eventually lend itself to a PC board. I'd like to get good at soldering now Thanks, - Earl
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Post by kaos116 on Jul 27, 2006 22:00:42 GMT -5
Hi Earl, Wow, there is so much that can be said about soldering. I'll try to keep it short. I have been soldering for over 20 years and actually spent 6 days learning high reliability soldering way back in the beginning.
Equipment: 1. Adjustable temperature soldering station. Ungar and Weller are both good names. Prices $40 on up to thousands. Expect ~$100 for something that will last for many many years. These units allow changing tips 2. Different size tips. Small chisel point for little work, big bulky tips for big buss jobs 3. Solder. I like 63/37 tin/lead that is .81mm in diameter. I seems to be the right size for 99% of my work. 4. Flux. I like the paste version, but it can be tough to find in a non-corrosive version 5. Solder sucker for desoldering. I never liked the solder wick, but guys at work use it all the time. Solder sucker is just that. It sucks solder. You push down on the end with your thumb and it's spring loaded. Once the solder is flowing, you push a button and SUCK, it's gone. 6. Tweezers, scribe, used dental tools. Anything to hold little parts while you apply the heat.
that's it for equipment.
Technique: There is a bit of an art work to getting a good solder joint. But some simple steps to getting a good joint. 1. Apply flux where you want the heat. This magical stuff tranfers the heat to where it is. that is not to say the wire or resistor will stay cool. They won't. 2. Heat the component not the solder. This one is a bit bendable depending on what you are soldering. If you have a resistor in a solder pad. you would touch a clean iron tip so it touches both the resistor lead and the solder pad. touch the solder to the resistor lead and wait for it to flow. If you apply the solder to the iron tip you can end up with a cold solder joint. Exception to the rule. Surface mount stuff is small and delicate. I usually hold the component in place with a scribe, put a dab of solder on the iron tip and just touch it to the pad that the SMD is on. This solder joint happens quickly. Under a second. Usually as fast as you can touch and remove. Too much heat to the SMD and it's no good. 3. 'The bigger the blob, the better the job.' is a myth. You want nice concave solder joints that are shiney. Joints that look like little marbles are bad. Suck the solder off and try again. 4. Shocking your solder tip works wonders. Right before you are to make a connection. you run the tip of the iron over a wet sponge. This does 2 things. It makes sure your iron is clean and it shocks the tip. This means it drops the temperature to where the soldering iron base unit starts applying voltage to the soldering iron, heating the tip. When you place it against the component it heats it up faster, not allowing too much heat to radiate into the component and stay consentrated on the lead. 5. Use sockets on all IC's. Scroungers find this usefull. First, you won't damage the IC with too much heat. Secondly, 2am seems to be the magic hour when you are out of an IC that is on another project. Last time I checked 7-11 stopped carrying PIC Micros ;-)
That's about it for the basics. Quick notes for the high reliability folks.
1.clean your solder with alcohol before use. 2.keep your leads as short as possible (RF issues).
I could go on....
It's fun.... and practice makes perfect. Even after 20 years I still get a bad joint now and then. Usually the iron is set too low.
Good luck!
Todd
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Post by thurstan on Jul 31, 2006 4:27:32 GMT -5
Well I just discovered that either my soldering skills have deteriorated or the new iron i bought just isnt hot enough! I thought an 18W iron would be suitable for electronics work, but either I am doing something wrong or it just doesnt get hot enough to heat the component to allow the solder to run. sure it melts the solder no problem, but solder on the tip is not what we want!
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Post by Excalibur on Jul 31, 2006 5:49:07 GMT -5
Do not forget to tin your soldering iron. When you first plug it in (assuming you've already cleaned the tip and all) at the moment it reaches a temperature to where it can melt the solder, apply a small amount to the tip and allow it to continue heating. This technique will allow it to transfer heat more efficiently than if it were just a bare tip.
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Post by pyrofer on Jul 31, 2006 7:28:53 GMT -5
I found that cheap crappy irons are a pain. Im about to invest around £100 gbp in a good temp controlled iron, I suggest you spend as much as you can on the iron, it makes all the difference!
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Post by thurstan on Jul 31, 2006 7:52:48 GMT -5
i did think about tinning the iron, but i thought most irons come already tipped. no harm in trying it when i get home!
100 quid on an iron! I couldnt justify the expense! Maybe if i get a nice bonus at work soon
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Post by pyrofer on Jul 31, 2006 9:00:41 GMT -5
It sounds a lot really, but if you solder a lot its worth it for the time youll save. Ive been soldering since I was 13 or so, thats nearly 20 years now! If id spent £100 on an iron then, it would have been quite good value by now, instead ive wasted money on lots of cheap ones over time and probably spent more Your right though, its a lot of money, i hope my wife doesnt find out!
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Post by gmoon on Jul 31, 2006 9:03:42 GMT -5
I've used wire-wrapping to good effect on other projects: It has a lot of positives: it's good for analog projects, it's fast, and works fine with digital signals (upto 30 or 40 mHz.) Also, it's inexpensive (although the WR sockets are getting harder to find.) Very easy to remove a wrapped connection, too (although there might be connections above whatever you're trying to remove ) You can whip up a board start-to-finish in an hour or two, less time than it takes to hand-route a pcb on your computer. Negatives: It's easy to make mistakes, it's more difficult to share projects with others (unless they're comfortable working from schematics) and only makes sense for one-off projects. Tips: Use the proto boards that have copper surrounding each drill hole. That way you can 'tack' the components to the board, in case the board is subject to vibration. The sockets can't be reused if they are soldered, tho. Wire-wrap connections themselves are quite strong, if you do it right...
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