I ordered SnapperGPS receivers from an electronics manufacturer and they asked me a question. What shall I reply?

[JonasBchrt]

To replicate SnapperGPS, it might be sufficient to upload the bill of materials (BOM), the Gerber files, the drill file, and the pick and place files to an online PCB manufacturing and assembly service. They will then source the components, print the PCB, and assemble the board.

However, sometimes they might come back with an engineering question.

[JonasBchrt]

Here is a compilation of popular questions and answer suggestions:

Q: A component is not available / out of stock. Please recommend a substitute.

A: Check the Notes column of the bill of materials for substitutes.

Q: What is the desired board thickness?

A: The board thickness shall be between 0.8 mm (lighter) and 1.6 mm (more robust).

Q: For purchasing of component XYZ, BIS is required, specifically, a description of the end product and the target market.

A: End product: A GNSS data logger for wildlife location tracking. Target market: Conservation biology.

Q: Here are some sample pictures of the assembled boards. Please check if the orientations and polarities of the components are correct or not.

A: Compare the component orientations with the component orientations in this picture. Carefully check each component that is not just a resistor (R) or capacitor (C). A dot in one corner of the component as well as text orientation can help with that. Specifically, ensure that the dot on the Connor Winfield D32G-016.368M, which indicates pin 1, is at the corner next to the board edge, as indicated by the arrow in the picture.

Q: The component that can be sourced is a couple of years old.

A: No problem.

Q: Drill holes and slots/profile overlap. Shall they be made as drill holes or slots/profile?

A: They shall be made as slots using the profile layer.

Q: What substrate shall be used?

A: For example, FR-4 is fine.

Q: What shall be used for the finish?

A: For example, hot air solder levelling (HASL) or electroless nickel immersion gold (ENIG).

Q: How many unique parts are there?

A: 31.

Q: How many SMT pads are there?

A: 62.

Q: How many QFP parts are there?

A: 2.

Q: How many through-hole components are there?

A: 1.

Q: What is the minimum track width / track spacing?

A: 6 mil (both).

Q: Please provide a "pick and place file" or a "centroid file".

A: You can find these files in the top level of the GitHub repository. They are named snappergps_1_0_0.mnb and snappergps_1_0_0.mnt, one for the bottom layer and one for the top layer.

All information without guarantee/warranty.

[JonasBchrt]

Update for V2.1.0 and V2.2.0:

Q: Here are some sample pictures of the assembled boards. Please check if the orientations and polarities of the components are correct or not.

A: Compare the component orientations with the component orientations in these pictures of V2.1.0 or these pictures of V2.2.0. Carefully check each component that is not just a resistor (R) or capacitor (C). A dot in one corner of the component as well as text orientation can help with that. Specifically, ensure that the dot on the Connor Winfield D32G-016.368M, which indicates pin 1, is at the top right, next to IC1.

Q: How many unique parts are there?

A: 32.

Q: How many SMT pads are there?

A: 60.

Q: How many QFP parts are there?

A: 2.

Q: How many through-hole components are there?

A: 2.

All information without guarantee/warranty.