How is on board soldering done ?

[roborg]

Hi,

I was trying to solder few wires to a small bi-polar stepper motor with 4 pins/lead blobs. Had I bought this motor separately it would have come with wires, but in my case I plucked this from old floppy drive and it has 4 pins/solder-heads (small blobs). I wanted to solder jumper cables to these blobs so I can hook this motor to breadboard but they are so close to each other it is becoming difficult to solder wires without short circuiting them. I have been examining few boards and there I can see soldering was done pretty cleanly even when the pins are very very close. How is it done normally ? If I can't solder the wires this motor is pretty much useless to me. Please send me suggestions or easy workarounds. If you want I can post pictures of what I am talking about.

Thanks,
RO.

[corrado33]

If you're asking how things like floppy drives and stuff are soldered so nicely...  Well, I'm going to guess it's all soldered by machines. 

[roborg]

If you're asking how things like floppy drives and stuff are soldered so nicely...  Well, I'm going to guess it's all soldered by machines. 

well some folks build custom boards/shields for their hobby projects ... how about them ?

Thanks,
RO.

[rbtying]

They use a solder wick.

[Soeren]

Nah, it's a question of using the right tool (a fine point iron), a steady hand, just the right amount of solder and pre-tinned wire of the right gauge.

But... When you compare the motor pads to regular boards, I kinda get the idea that those pads aren't all that small after all - what size are your pads and what is the minimum distance between them?

Anything from 2mm pads with 0.5mm between them and up is quite trivial for a trained hobbyist.

[Admin]

When I have wires that close, I use heat shrink to insulate everything.

See the pics here:
http://www.societyofrobots.com/schematics_photoresistor.shtml

[kd5kfl]

factories use wave soldering. board slides alonf a track over a pot of molten solder. solder is agitated into standing waves. like this...

wavesoldering

[corrado33]

That's cool!  I'm guessing flux is sprayed on?  Then the solder only touches the tips of the pins and flows to the coldest point (the board) thus creating a nice joint?  If so then... cool!

[Chuckt]

It sounds like you are talking about surface mount soldering.  It requires flux, fine tipped tweezers, a soldering iron with a fine pitch, an exacto knife and a magnifying device.  They suggest using a chizel soldering iron (1/32nd of an inch) because it can hold the solder and they generally want you to have a temperature controlled iron.  When it doesn't work, you need to remove the solder with solder wick.

There are youtube tutorials online and I'm still learning.

Surface Mount Soldering 101