SDG #166 Creating Ring Light Pick and Place Files for JLCPCB's Assembly Service

This episode moves the LED microscope ring light project from a hand soldered prototype to a board that can be built by a turnkey SMT assembly house. The focus is the documentation rather than the hardware: exporting a centroid (pick and place) file and a bill of materials from the EDA tool, then reworking both so that the assembler’s software actually accepts them.

The practical value is in the details that catch people out the first time they order assembled boards. Component designators in the BOM have to match the designators in the position file exactly, footprint and value columns need to be present and unambiguous, and every line item has to be mapped to a part number from the assembler’s own stocked library rather than a generic manufacturer code. Parts that are not in stock either need substituting or omitting for hand fitting later, which is a real design constraint worth considering before routing the board.

Rotation and origin conventions receive attention as well, because these are the classic causes of parts fitted backwards or offset. Polarised components such as LEDs, diodes and ICs need their rotation values checked against the assembler’s expectation, and the board origin used for the export must align with the origin implied by the Gerbers. Column headers and units also matter, since the upload parser is particular about naming and about millimetre versus inch values.

For anyone with a working prototype and a batch of boards to build, this is a useful walkthrough of the file preparation step, and a reminder that a few minutes spent verifying rotations is cheaper than a reel of misplaced LEDs.