Solder paste printing, assembly and reflowing

A project log for Optically Isolated USB-UART Adapter

Optically Isolated USB to Serial Adapter. Up to 2Mbaud. 1.8-5V logic. No electrical connection between your device and the USB port.

zeptobitZeptoBit 12/01/2017 at 22:480 Comments

The solder paste is applied using a stainless stencil from These stencils are very nice and easier to use than plastic stencils. Result in next picture.

All the parts layed out. I use a home made vacuum pickup tool to place the parts. It uses exactly the same vacuum system as my never ending PNP machine project.

Reflowing in my converted toaster oven. As you can see in the picture the IR heaters are on, but it uses mostly convective heating. The IR is only on ~20% of the time during a typical reflow. (BTW, the gray fuzzzy thing in the top left corner is not smoke, it's light reflecting of the glass door.)