I’ve decided that I want a solder paste dispenser. Whenever I do SMD soldering with solder paste, I usually end up trying to dab solder on the pads with a toothpick. This method makes it very hard to get the desired amount of paste on the pad.

You can buy several commercial dispensing units. Generally, an external compressor supplies compressed air and inside the unit is a regulator and some sort of timer. When a valve opens, it puts air pressure behind the solder paste in the syringe, causing it to be forced out at an even rate. However, these units generally cost well over $100 USD. I would like to have one, but for that price, I’d like to build my own and be able to customize it to my needs.

I will first start with the pneumatic portion of the system. Below is a tentative schematic for the pneumatic system.

For the air supply, I have plans for an upcoming project of making my own compressor system. I don’t have many details decided, but one of the things I do know at this point, is I want the connection system to be the push-to-connect type air connectors like this one

 

With these connectors, you simply push in the tubing and it makes a good seal. I find this to be a very clean solution that is easy to modify if I need to. Upcoming is all the details of the pneumatics, the electronic portion, and the enclosure I will put this in. More updates to come.