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How do You Surface Solder???

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Iawia

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Hi All,

Before I got into electronics a while ago, I knew a guy that always soldered from the top of the board instead of from beneath. That way we could easily see all the connections alot more clearly when we had to troubleshoot.

I've searched on the web, and found little on this subject. I have been soldering from beneath the board mostly, but now that my devices are getting more complex, I am interested in this technique. Any good resources that you can suggest to find out how to solder directly onto the top surface of a protoboard?

Thanks,
Iawia
 
Are you talking about top side soldering of through-hole components or surface mount components?
 
I did a quick search on the forum, but didn't see much. Thanks John, I will chk it out. The problem that I am having is, one microtwitch of my hand and the next pin gets soldered accidentally. So instead of spending all my time soldering, I am de-soldering. I saw another video where the guy was soldering twenty pins at once but the solder did not stick to the other pins. It was amazing. Maybe your vid has something on that.

Thanks.
 
If your hands shake, soldering individual SMD's will be a problem. Experiment with various hand positions to find one that works better. Rest your wrist on the table, hold your breath, etc. There are lots of techniques to improve steadiness.

That video makes some good points. I usually use the spot of solder to get one pin or end attached to the board. I have a couple of pieces of small diameter music wire (ca. 0.030" to 0.045") that I have tapered and smoothed the ends of. I use them for positioning and pushing things around. With the dot of solder method, you can use one to hold the component in place so it does not get bumped off the pad when you touch it with the iron. A dot of paste flux can also help keep the part in position.

Another aid is cyanoacrylic glue ("CA" or "superglue"). Something about medium viscosity works well. I usually use some old thin stuff that has thickened with age. I put a drop on bare copper PCB board -- anything will work that doesn't set off the polymerization reaction. Use one of the aforementioned pieces of wire to dip in that puddle and then make a micro dot on your PCB. Add the component. You will have a few seconds to move it around to the right position. Once the CA sets, then soldering is easier. Of course, avoid getting the CA where you want to solder, but if that happens, you can solder through it. CA will vaporize at solder temperature. I would use the CA method only if I could not get decent results with one the methods mentioned previously.

John
 
CA method is new for me, I'll try it next time :).

for me I'm using tweezers to hold the SMD components during soldering process, but before that, I'm applying some solder on the components ends and on the PCB, then hold the component in place and touch with the soldering iron tip to stick it, and if required, I add more solder.

shorting two pins is likely to happen, if you are:

1- You are beginner,
2- Not using proper Iron tip,
3- Your hand not supported,
4- You need power glasses ;)
 
Hi,

Yeah the video shows how to solder surface mount parts by soldering the whole side of pins at one time, then solder wicking off the excess if needed. I havent done it this way yet but it looks easy.
I've also made boards where i put rectangular pads for the parts like resistors instead of drilling holes. Bending the lead a little and snipping off the excess and then soldering to the top of the board. These were not SM resistors just 1/4 watt and even larger parts. Once the lead is bent at the end (maybe 1/8 inch only) it can be soldered to the top of the board. Not as mechanically solid as a through hole mount but it works.
 
What kind of solder are you using? If you are still using 60/40 it will never work. 63/37 has to be used if using lead solder. With 63/37 the solidus and liquidus points are the same, so the solder solidifies instantly. Even on a large chip, all you have to do is attach the corners and drag a blob around the edge. I actually prefer to solder these large chips with the chip facing down in the air and the soldering iron facing up. 60/40 will bridge all of the time.
 
Hi Keep,

Oh that's good to know too.

I also forgot to mention that i used Elmer's Glue to glue the chip down first, at one side not in the center. I used that glue instead of Krazy glue or other instant glues because it gave me more time to adjust the position to get it really accurate. It dries in about 15 minutes so it takes longer yes.
In the video he tacks one corner pin down with solder and that works too if you want to try that, but i suggest trying it on something not too important first to see how it works.
 
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