To add a little to the existing replies. When you buy surface mount parts, they normally come on tapes - little plastic/cardboard strips with indents that the c

To add a little to the existing replies. When you buy surface mount parts, they normally come on tapes - little plastic/cardboard strips with indents that the components sit in and a film over the top. These tapes are sold as reels if you need lots of units, but most hobbyists buy "cut tape" which the big distributors offer. In a production setup, the pick and place machine accepts the reels and uses a vacuum tool to pick the parts up. It knows the orientation of the part in the tape (which is fixed) and where it needs to go on the board. Often components with irregular tops (usb connectors for example) will have small piece of kapton tape fixed to them to aid pickup. This is important: if you're doing this with tweezers, it's often annoying to pick the parts out of the tape and if you dump on the table you usually have to flip things the right way up, rotate them, etc. So a vacuum tool makes that a lot easier. Small pens already exist and so do diy options like aquarium pumps, but this is a really polished looking project and great if it's open source too.