Thin laser-cut steel sheet with holes over each SMD pad; you squeegee solder paste through it before placing parts. Thickness (4-6 mil / 0.12-0.15 mm) sets paste volume.
How it looks
Real geometry: CORE3588 paste openings from our board file
The holes in CORE3588's stencil, top right corner (28 x 20 mm): every amber shape is a hole cut in the steel where paste goes. Drawn from the pads that have paste in our board file; the real cut file is core3588-F_Paste.gtp.
1Tiny openings for the 10-pad power chip (U1).
2Openings for the USB-C socket's pins.
3Two openings per resistor or capacitor.
Real text: from the CORE3588 fab pack
Our stencil order, word for word. Only the top needs one: every CORE3588 part sits on top.
How it works
Where it fits
The stencil is cut from the paste layer of the Gerbers. It is the first step of turning a PCB into a PCBA.