What is the basics for SMD soldering

novolts

Senior Member
#1
Guys
I know this is not exactly a picaxe question
I would like to attempt SMD soldering and I would like the advise of forum members please I have been on the internet but most of the stuff is towards a sales pitch rather than good solid information that's why I am posting my question here
What I need to know is what are the tools required to start, my wife recently bought me a 30 watt soldering iron from a well known German supermarket and I am plesantly suprised at how good it is for the cost, would this get me started on the soldering side it has a very fine tip
I have no intentions of reworking at the moment
Any advice would be appreciated and sorry if members are annoyed by the post
novolts
 
#2
I've only done a small amount of SMD work, but what I did was use solder paste and a hot air rework tool. I found this worked well, and was easier than trying to use a soldering iron. The hard part at first was getting the solder paste in the right place. Initially I used a syringe and fine needle, which was pretty tedious, but the last lot I did I had stencils made and used a backed razor blade to spread the solder paste on to the board, which was a great deal quicker and gave much better results.

Using a hot air station is slow, especially with larger boards, but it's an easy technique to learn. I'm not that interested in doing more SMD work, mainly because I find it easier to use through hole stuff for anything I tend to build, but if I was I think I'd probably look to get something like a cheap hot plate.
 

erco

Senior Member
#3
Many techniques, including over-soldering with big blobs then using solder wick to remove. Cleaning the board is top priority. This guy shows great technique. EBay sells many cheap kits to practice on, search "SMT practice".

 
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#5
Many techniques, including over-soldering with big blobs then using solder wick to remove. Cleaning the board is top priority. This guy shows great technique. EBay sells many cheap kits to practice on, search "SMT practice".


Thanks for posting that, those soldering skills are pretty impressive! The only observation I'd make is that it's a technique that would only work on a board with a solder mask; I'm not sure it would work well with a plain, home etched board.
 
#6
I have used manual techniques for hand soldering various SMD components up to 32 pin SIOC chips. Smaller ICs with 6 to 10 legs and legs at spacings like 0.5 mm have also been soldered.

My method is:
1. to pre tin the pads and IC legs.
2. Then align the IC/component in place and hold the IC with a scalpel blade or other small area device
3. “Tack” the first leg and check alignment
4. Solder the other legs and return to the first leg.

I use a 0.2 mm conical tip and 0.5 mm rosin cored solder.

I have found it difficult to remove solder bridges between pins so work to avoid solder flowing over all the pins.

With increasing age, there is a need for good magnification to check IC laser etched identify, orientation and alignment with pads.
Some recent IC’s that I used were 1.0 x 1.5 mm body with 6 legs and I was using the iPhone camera to verify the IC orientation before soldering.
 
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mikeyBoo

Senior Member
#8
I agree with westaust55’s method. I just did some MSOP10s this way & it worked fine. Coating the chip & the board (masked or homemade) with a flux pen will make the solder flow onto the pins & prevent solder bridges. The flux will also hold the chip in place.
Keep the tip of the iron away from the chip pins. Use a magnifying headset & you will see the solder flow onto the pins.
If you are an older guy (like myself) the magnifier is not optional. The wicking method may be used to correct mistakes but you may damage the chip.
For what-it’s-worth dept., here’s what I used:

Bausch & Lomb Magna Visor with Lens Set
http://www.bausch.com/our-products/vision-accessories/professional-magnifiers/magna-visor

SRA #312 Soldering Flux Pen Low-Solids, No-Clean 10ml - Refillable $9.70 Prime
https://www.amazon.com/SRA-Solderin...10ml+-+Refillable&refinements=p_85:2470955011

These are nice because 1 side of the board is MSOP10 & the other side is SOT23
uxcell 50Pcs 13mmx10mm SOT23 MSOP10 UMAX to DIP10 0.5mm/0.95mm PCB Adapter Converter $4
https://www.amazon.com/uxcell-13mmx...id=1500819988&sr=1-11&keywords=msop10+adapter

Almost forgot: Clean the board with alcohol using an old toothbrush.
 
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