During testing and debugging, it’s common to refer to pin details while connecting different modules, sensors, or devices. Usually, this information is printed directly on the PCB silkscreen. In some products, especially those that come with an enclosure, labels or screen-printed markings are added on the housing.

For bPiShift, however, space on the PCB was very limited - too limited to add silkscreen pin labels. We also didn’t want to use an enclosure, as that would make the module bulkier and more expensive. Our first idea was to place a sticker on the connector with pin details, but we quickly realized it might peel off during repeated insertions and removals from the Raspberry Pi.

That left us with two practical options: screen printing or laser etching. Screen printing on such a small component can be tricky and is usually better suited for high-volume manufacturing. So, we decided to give laser etching a try.

We considered two approaches: laser etching after PCB assembly, or etching the connectors before assembly. Etching after assembly would mean that any mistakes could damage or ruin a finished PCB, while pre-etching the connectors would only require careful alignment during assembly. To keep the process simpler and cost-effective, we went with the second approach - laser etching the connectors first, then using them during PCB assembly.

Our initial experiments taught us that we needed a small fixture to hold the connectors precisely during the etching process. We designed and 3D-printed a simple jig that made alignment consistent.

To ensure we didn’t etch the wrong side, we first printed the pin labels on paper and taped them onto the connector as a guide.

This method worked really well - providing accurate, repeatable etching of the pin labels on both sides, as well as the product name and logo on the front and back of the connector.

The result is a clean, permanent way to label every bPiShift connector, making pin identification effortless while keeping the design compact and professional.