Need tips on soldering
whiteoxe
Posts: 794
I could really use some tips on soldering. I had a great little battery operated one with a fine point(talking about solder iron) ?I found it pretty good at not accidentally joining pins together and just getting the right amount of metal on a pin.
but ive bought a cheap iron off ebay and soldering headers to the quickstart board was hard. the tip is pretty large, I think standard size but larger than the unit I used to have. It also gets very hot quickly so I pull the cord from the socket at times then plug back in.
one way of soldering the pins was to melt the solder onto the iron then touch the pin with the dripping solder and that then stuck to the pin and hole.
I did get two VDD 3.3volt pins joined together accidentally doing this. I just hope that doesn't upset anything in the future. I miss the fine little battery operated unit I had. it was cheap and nasty but easy to use , more so than the one ive just got.
but ive bought a cheap iron off ebay and soldering headers to the quickstart board was hard. the tip is pretty large, I think standard size but larger than the unit I used to have. It also gets very hot quickly so I pull the cord from the socket at times then plug back in.
one way of soldering the pins was to melt the solder onto the iron then touch the pin with the dripping solder and that then stuck to the pin and hole.
I did get two VDD 3.3volt pins joined together accidentally doing this. I just hope that doesn't upset anything in the future. I miss the fine little battery operated unit I had. it was cheap and nasty but easy to use , more so than the one ive just got.
Comments
The thing about soldering is that you need "flux" to cut through any oxidization on the metal surfaces, and exclude oxygen as they are heated (heat causes rapid oxidization). Then your solder can flow around the metal and its surface tension will pull it into place.
Regular solder for electronics contains flux. But if you melt the solder onto the iron by the time you have fiddled around getting on to the joint the flux has burned off, can no longer do it's work and you have a very good chance of a "dry" joint. Possibly not even connecting things electrically and being unreliable.
Solder and iron need to go onto the joint at the same time.
As Leon says, get yourself a nice iron. With a nice chisel bit. You don't want an ultra fine pointy thing because thin points don't transfer heat effectively. Many insist that you have a soldering station with temperature control etc. I have only ever used that at work. At home I have a cheapish Weller that plugs straight to the mains.
There are hundreds of vids on how to solder on the you tubes. I like these:
http://www.youtube.com/watch?v=J5Sb21qbpEQ
Do watch all the parts.
Get your self set up nicely otherwise you are going to have a miserable time of it. It does not have to be horrible expensive to do so and these things last for years and years.
1) Don't leave your soldering iron on all night, else you may need a new soldering tip.
2) Don't hold the metal part that you may be soldering with your fingers, else you may burn your finger tip.
3) Don't forget to tip your waitress.
the first was a real overload of information but still good to know some of it, the second video https://www.youtube.com/watch?v=fYz5nIHH0iY really showed different ways of soldering well.
I,m going to keep those links for future..
Hope you've got a good day job jazzed, there's thousands of comedians out of work
The tip should be about the same size as the thing that is being soldered, for optimum heat transfer.
Metcal makes a special 'mini-hoof' cartridge that holds a small amount of solder. The IC is tacked down using two opposite corners ensuring that it is correctly positioned, flux is applied to all the leads, and the tip is wiped along the first row of leads. The remaining rows are soldered, reloading the tip with solder for each row. This technique is called 'drag-soldering'.
http://www.youtube.com/watch?v=J5Sb21qbpEQ&list=PLa_0rl-N6O8j_aL0j8A2x5sEpVWuYwjVT
thanks but that's where Heater sent me to , basically.
The bottom of the QuickStart board uses this extra copper as part of the ground network. While this copper area is generally covered with a layer of solder resist (the blue paint) it's still possible to cause shorts to the ground if large solder blobs extend over the copper pour.
You PM mentioned some of the Vdd pins being joined together on the bottom of the board with solder. This probably isn't a problem but if the solder extends over the ground area there is a risk of the Vdd line shorting with Vss (ground).
You could measure the resistance between a Vdd pin and a Vss pin to see if you have a short (the resistance should be several thousand ohms). You could also post a photo of the area of the board you're concerned about and we could let you know if it looks like there could be a problem.
Like many things, soldering gets easier the more you do it.
Always, always, always keep your tip tinned (covered with solder).
Clean the joint before soldering with high strength alcohol, because solder will not stick well to a dirty joint.
Remember that solder flows towards the heat source so touch the solder OPPOSITE to where the tip is.
Don't hold the tip to the joint for a long time, otherwise the traces can separate from the circuit board.
Add a little flux, such as from a flex pen, if a joint is difficult to solder.
Use the right tip and iron for the job since bigger connections will need more heat.
Keep your tip clean by wiping it periodically with a sponge.
Put a big blob of solder on the tip if you are done or will not be using the iron for a little while.
Use only the temperature that you need, since a higher temperature corrodes the tip faster.
I prefer eutectic solder (63% Sn, 37% Pb) because it hardens faster than 60-40 but it's more expensive, I also like to "clinch" the leads so the part doesn't move while I'm soldering it. I also prefer good old fashioned rosin flux because I will remove the flux anyway so I can inspect all the joints. I've always felt comfortable with Weller fat irons but some people like the long thin irons.
Whatever iron you get, look for one where the tip goes into the heater of the iron. The tip of a cheap iron has very contact with the heater.
I didn't creat a short by soldering the header as you worried I might have. I did a few tests to be sure.
I am also going to post a video focusing on my quickstart behaving strangely, something is broken I fear. I wired up the SN754410NE motor controller to a breadboard and the quickstart and a single motor. I could not get the motor to budge . I triple checked my wiring of the chip and the QuickStart. I haven't mentioned this because I felt so lost and thick headed. I used SimpleIDE, that was the catalyst for my postings about forgetting about C and going back to Spin.
I toyed around with the Quickstart this morning just to light a LED. I discovered all the even numbered pins are not giving any output. All the odd numbered pins work fine.
That's not the end of it.... the pins that are marked odd are the even pins and the pins marked as even are actually the odd pins. I think this will be clearer when ive posted a video. Would the Robotics forum be most appropriate ?
Back OT. A couple of years ago I treated myself to an X-Tronic Soldering/Rework station. It is all digital, has very good temp control, a wide variety of tips for soldering and rework and it has suction. I think I paid $160.00 for it shipped and thus far I am very satisfied with it. I also have a butane soldering iron that I use on job sites that also works very well. However, as others have stated, flux is a must!!!
No not a sponge out of the shower. They are plastic and will melt into a horrible mess!
We are talking real sea creature sponge (Correct me if I wrong someone, I'm just guessing that's what they are made from)
Anyway, if you happen to find you don't have one, you can buy such sponges from the girls make up department of your local supermarket. Girls use them for powdering their noses, or whatever it is girls do with them.
They are generally yellowish and round. You can cut them to shape to fit the little tray in your soldering iron stand.
If anyone looks at you strangely or asks in the make up department, be ready to say you need it for 'er in doors.
The blue is solder, black is the hole and lead. Look for a nice rising edge. If it bleeds over to the next hole you used a bit too much solder, try another with a little less. To remove solder use another conductor of heat, braided wire, desoldering braid, just about anything even a clean soldering iron tip should suck it up, otherwise it's not clean enough.
[IMG]https://dl.dropboxusercontent.com/u/79058769/pics/robots/Soldering/through hole.jpg[/IMG]
The Metcal sponges I use are made of cellulose, but they now seem to favour a brass pad.
Cellulose...that makes sense. Thinking about it a real sea sponge type sponge is lot more limp if I remember correctly.
I have wondered about those brass "sponge" pads. Do they work well?
The brass pad thing just doesn't sound as satisfying some how. Have to give it a try I guess.
http://uk.farnell.com/jsp/displayProduct.jsp?sku=1705197&CMP=KNC-GUK-FUK-GEN-SKU-MDC&mckv=sIS8GaINI|pcrid|39078108968|kword|mx-w1av|match|p|plid|&gclid=CL67hOO05b8CFfOhtAods1QALA
The tip saver feature won't work with my ancient STSS power unit and it's made for the MX-5000 handpiece rather than my MX-500 handpiece.
I was recently thinking about splashing out 40 odd euro on this:
http://www.batronix.com/shop/soldering/Atten-AT937b.html
or this:
http://www.batronix.com/shop/soldering/Atten-AT938D.html
I think I prefer a nice big knob to turn rather than the digital push button thing. Why can't they make one with digital temp display and a big knob to turn? Sounds like a Propeller project right there!
The thousand euros is being saved up for a nice new Rigol scope:)
is it at all possible this mess is why none of the even numbered pins are working but all the odd numbered pins are. I wondered why I couldn't get the sn754410ne motor controller to work, but I was using even numbered pins in simpleIDE.
I tested all the pins by lighting a LED. ALL THE EVEN NUMBERS FAILED ? capslock!!!!!
Far two much solder of course.
Thing is, when the solder balls up into big round blobs like it means you cannot see it flow nicely around the surfaces you are trying to connect. If your surfaces are a bit corroded, which they always are, or greasy and not clean, then the solder may not have "wetted" it nicely. That could mean no electrical connection or at least an unreliable one. You have no way to see how good it is under the blob.
Then there is the risk of big blobs causing shorts to nearby tracks of course.
When I come over I will give you a few quick tips but I can see straight away that you are making the age old mistake of melting the solder with the tip onto the joint. If you push your tip as if to wedge it against the pad and the pin and feed just a tiny amount of solder in between the tip and pad then wait a second for it to heat up the pad and pin, and then feed in some more solder, holding that for another second, you will end up with a pretty good solder joint.
Of course if the pad is part of a thick ground plane or the pin is rather large you may need to preheat the joint a second or two longer even feeding small amounts of solder at this point, just enough to help it to conduct the heat from the tip to the pin and pad. I find that rubbing that tip back an forth a tiny amount at this preheat stage helps to improve the preheat. Once the pin and pad are hot enough then feeding on the rest of the solder means it will melt and bond on contact with these surfaces. So you see the tip is not for melting solder really, you just need to make the pin and pad hot enough first.
just finished watching the F1 race in Hungry, congrats to Dan Riccardo and again to my online betting account !! I can soon get a soldering station at this rate
You want a little bit if solder on the iron to help the heat transfer from the soldering iron to the pin/PCB. If you place a "dry" soldering tip against the pin/PCB, you don't get the heat to transfer as fast as with a "wet" tip.
Here's a picture of the bottom of one of my QuickStart boards.
Had I known I was going to photograph the solder, I would have been more careful as I soldered the headers.
I used a red X to indicate a joint which doesn't look very good. The three green check marks indicate the joints which IMO, look the best.