Manual Assembly of a Surface-Mount RP2040 Dev Board Using a DIY Laser-Cut Mylar Solder Stencil

This video demonstrates the manual assembly process that I typically use to build surface-mount printed circuit boards when I have a solder stencil. In this case, I am using a DIY solder stencil that I cut from a 4-mil-thick sheet of mylar using a K40 laser cutter. The board features an RP2040, which is in a 56-pin QFN package with a 0.4-mm pad pitch, a USB-C connector, which has a 0.5-mm pad pitch, and a number of 0402 resistors and capacitors. The laser-cut mylar stencil does an excellent job even with these small components with very fine pad pitches. The Arduino-pico project is located at https://github.com/earlephilhower/ard....

Sources for the various supplies that I used:

• Removable double-sided mounting tape: https://www.amazon.com/gp/product/B00...
• Plastic spreader: https://www.amazon.com/Plastic-Body-F...
• Thermally stable SAC305 solder paste: https://www.digikey.com/en/products/d...
• 15-mil-diameter SAC305 wire solder: https://www.digikey.com/en/products/d...

Video describing the process of making the stencil:    • Laser Cutting Quality Low-Cost Solder...  

Video describing the vacuum pick-up tool:    • Low-Cost Vacuum Pick-Up Tool for Surf...  

Video describing the parts sheet:    • Managing Cut Tapes in Manual Surface-...  

Chapters:
0:00 Applying Solder Paste
5:32 Placing Components
26:17 Reflowing the Board
30:10 Board Inspection / Through-Hole Soldering the USB-C Connector
33:22 Testing the Board