Welcome

This website contains information about my hobby electronics projects.

What is a miniPCB?

A miniPCB is a printed circuit board with a simple electronic circuit. The mechanical design is small, simple and usually has a standard pin interface. So miniPCBs with similar circuits work well with docking boards to interface with lab equipment.

Part Categories

miniPCBs are grouped in categories and subcategories based on their circuit function. The list is incomplete and will continue to change as I progress.

Part Numbers

miniPCBs and their documents are uniquely identified with part numbers.

While using EAGLE, I assigned one part number per part. The schematic filename and board filename needed to match; so one part number made sense. But Altium's different. I'll probably recapture parts created in EAGLE and reclaim those part numbers in the process.

Now that I'm using Altium, I've begun to assign one part number per part-document. It's not the best way; I feel a change coming. I still don't know the best way.

Documents that get part numbers include:

1. Schematic, SCH

2. Assembly, PCBA

3. Board, PCB

4. Bill of Materials, BOM

Documents that might be getting part numbers in the future include:

1. Panel of PCB

2. Panel of PCBA

3. Developmental Test Plan

4. Developmental Test Report

5. Manufacturing Test Plan

6. Manufacturing Test Report

7. Service Test Plan

8. Service Test Report

Variant Identification

When it exists the variant ID will be added between the document and revision characters.

The variant ID progresses: 00, 01, 02, 03, etc.

Revision Identification

Final release revision identification increments A1, A2, A3, etc. for minor revisions, and A1, B1, C1, etc. for major revisions.

Prototype revisions increment similar to: A1-01, A1-02, A1-03, etc.

Board Designs

To save time and minimize errors, I created an Altium library called NM-BOARDS. I add new/custom board designs whenever necessary.

These are some of the board designs.

Reference Designators for Connectors

The reference designator for connectors is either J or P, depending on what it connects to.

The prefix J is used to reference the less movable connector.

The prefix P is used to reference the more movable connector.

Layout Strategy

miniPCB layouts are generally simple and follow these guidelines.

1. Place components on top side only.

   • For SMD circuits on 2 layers, route traces on top side to keep bottom side ground plane as uncut as possible!

   • For THD circuits on 2 layers, route traces on bottom side to keep top side ground plane as uncut as possible!

2. As best possible, keep everything on a metric grid.

   • Placing large components: nominal grid size 1.0mm.

   • Placing small components and vias: nominal grid size 0.5mm.

   • Routing traces and compressing small components: minimal grid size 0.01mm.

3. As space allows, keep traces wide.

   • For SMD circuits, nominal tace width of 0.3mm.

   • For THD circuits, nominal trace width of 0.5mm.

Testing Strategy

1. Plan tests for developmental, manufacturing and servicing test events.

   • For developmental tests: think probe wires soldered to test points.

   • For manufacturing tests: think bed-of-nails fixture per panel.

   • For servicing tests: think clips, jacks, or plugs for handheld test equipment.

2. Include test points/connectors as needed.

Developmental Testing

When it comes to developmental testing, pick a level of rigor that works for you.

1. Untested / tested by end-user.

2. Tested with/without a plan.

3. Results recorded/not recorded.

4. Determinations documented/undocumented.

Test Documentation

The best developmental testing documentation I've completed had twelve pieces of information for each test.

1. Identifying Number

2. Name

3. Description

4. Purpose

5. Scope

6. Equipment List

7. Setup

8. Procedure

9. Data (Example if plan, Recorded if report)

10. Acceptance Criteria

11. Results

12. Conclusions

My employer had recently paid consulting engineers a bunch of money for a developmental test plan template. And I ran with it. If I remember correctly, my test report was approaching 90 pages. It was brutal. I practically lived at work for a week. I delivered on time and the project manager responsible for the product called me to thank me and say that it was the best developmental test report he'd seen in the ~20 years he'd been working at the company. Gotta admit, I was already proud of my work - but his gratitude is something I'll never forget.

I don't even know if he was just being a good project manager, or if my work genuinely exceeded his expectations. The stories we'll never know, right?

You literally read all the way down here! I'm impressed. You should consider contacting me here.