Being a little bit overwhelmed when looking at all these electrical components which are getting smaller and smaller? Well not any more!!
The way to solder smd chips is using "Solder Paste" instead of you're normal roll of tin. Solderpaste is like tin, but mixed with some chemicals to make it a mud-like substance. This makes things so much more easy.
I will be using a paint stripper of "heat gun" in this tutorial because i think this is the easiest way, bus allso a lot of people use ovens or these heated pads to make coffee, all are fine ass long as you can get above the melting point of your solder paste.
Before you start ordering solder paste there are some characteristics you should look for, namely:
- Make sure solderpaste is " NO-CLEAN", this just means that when you're done soldering you dont have any leftovers which you have to clean.
- Make sure you're get solderpaste which DOESN'T REQUIRE A TEMPERATURE PROFILE, this means you can just heat up the solderpaste, instead of the "classical" solderpaste which all require you to heat in different stages over a time profile. A big hassle you probably dont want.
- Look for a solderpaste which has a MELTING POINT OF 180 DEGREE CELSIUS, instead of 240 C, also to make thing more easy.
- Last but certainly not least; MAKE SURE IT IS A SYRINGE OF SOLDERPASTE!! not in a can because than you probably need a solderpaste stencil as well. (more on that later)
Okay go get some!!
about the paint stripper, the one i use is a 1800 Watts 300/500degree celcius ( 2 modes). You probably need atleast a 300 degree one, but i haven't tested this.
Well time to get started, i assume you already have your pcb done. If not follow this link to see the tutorial about making pcb's with the modela-mdx20 in the fablab. link
Make sure you're not using to much solderpaste, its easier to re-solder instead of desolder!!
This is more than enough solderpaste for low amp components.
use tweezers to place the components and genly push them down.
although its not completely necessarily i strongly recommend to apply a little bit of solderpaste to each individual pad of a chip, and put a little solderpaste on evere pin of a chip aswel. ( just take the chip and push all the pins inside the syringe one at a time)
After all the components are placed take your heatgun and heat the board. Try to spread the heat equally over the board.Make sure you keep your gun perpendiculair above youre board, else you will blow away the parts.After a short time( aprox 1 min.) you will see the paste melt and become silver. Wait a couple more seconds and you're done!.
Also notice how the surface tension and the heat will make the chips self-align, so if you placed a chip with a small error, this won't make an impact.
finally a clip of the soldering of this board:
http://www.youtube.com/watch?v=8iccjTReN70
well thats that, Best of luck!
copyleft by Sander Amelink,
All rights granted!