Imported from GitHub: oresat/oresat-c3-hardware · commit e3c66e4
Description
C3 (Command, Communication, and Control) our Command and Data Handling (C&DH) card.
README
title: "OreSat C3 Card"
subtitle: |
Fabrication and Assembly Information
For build TIME-STAMP
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About this Board
Board Description
The C3 ("Command, Control, and Communications") card is the main on-board computer (OBC) / housekeeping unit (HKU) / Command and Data Handling (CDH) subsystem for the open source OreSat CubeSat system. The C3 card:
- Connects to the backplane with a main connector and two RF ports
- Has an L band radio receiver based on the AT86RF215.
- Has a UHF radio transceiver based on the AT86RF215
- Has a radiation tolerant watchdog timer (with a cheap commercial replacement if you're not going to orbit)
- Controls the OreSat Power Domain (OPD), which turns on and off and controls other cards
- Talks to both CAN OreSat CAN busses
Documentation Links
- C3 hardware Git repository: https://github.com/oresat/oresat-c3-hardware
- C3 software Git reposity: https://github.com/oresat/oresat-c3-software
- TODO: C3 Design Notes + Design Review Notes
Documentation Files
| Filename | Notes |
|---|---|
| README.pdf | This README file |
| PROJECT-NAME-outline.dxf | Board outline (with holes) in DXF format |
| PROJECT-NAME-pcba.step | 3D model of PCBA (with components) |
| PROJECT-NAME-render-bot.jpg | Render of the top of the 3D model |
| PROJECT-NAME-render-bot.jpg | Render of the bottom of the 3D model |
| PROJECT-NAME-schematic.pdf | PDF of board schematics |
Contact Information
- Website: https://www.oresat.org/
- Email: [email protected]
- Instagram: @pdxaerospace
Board Renders
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Printed Circuit Board (PCB) Fabrication Information
Board Info
- 4 layer board
- Bounding box is 99.8 x 94.6 mm (3.93 x 3.72 in)
- Board thickness is 1.59 mm (0.063 inch)
- Important: See Materials and Stack Up sections below
Board Requirements
- Design Rules
- Minimum Trace / Space design rules
- Outer layers: 0.127 mm (5.0 mil) / 0.127 mm (5.0 mil)
- Inner layers: 0.127 mm (5.0 mil) / 0.127 mm (5.0 mil)
- Outer dimension router tolerance: +/- 0.254 mm (10.0 mil)
- Hole placement tolerance: +/- 0.075 mm (3.0 mil)
- Inner tab routed slot tolerance: +/- 0.254 mm (10.0 mil)
- Minimum Trace / Space design rules
- Drills
- Drill Positional Tolerance: 0.051 mm (2.0 mil)
- Drill Size tolerance: +/- 0.064 mm (2.5 mil)
- Plated/Un-plated holes
- There are 6 un-plated (NPT) holes
- There are 1477 plated through (PTH) holes
- PTH minimum diameter: 0.254 mm (10 mil)
- PTH minimum annulus: 0.102 mm (4 mil) radius
- Outline/Routing
- Requires a 1.0 mm or smaller diameter routing bit
- Slots
- There are no slots.
- Cutouts
- There are no cutouts
- There are 3 fiducials on the top layer.
- Panel tabs ("mouse bites")
- Card edges must be smooth; no mouse bites or other intrusions into the card outline.
- If external mouse bites are required, minimize and customer will remove by hand before assembly.
- If not otherwise specified, build to IPC 6012 Class 2 or better.
Materials
- Controlled impedance
- The stackup is critical for the performance of high speed signals on this board.
- As long as the stackup is controlled, the board is not considered controlled impedance.
- Isola FR408HR or material with equivalent Dk.
- Board Surface treatment should be ENIG, althogh immersion Silver is acceptable.
- White silkscreen on top and bottom surface
- Taiyo PSR-4000 or equivalent soldermask on top and bottom, no requirements for color.
Stack Up
| Layer | Thickness | Notes |
|---|---|---|
| Top Copper | 0.043 mm / 1.7 mil | Layer 1 foil, 1 oz Cu after plating |
| prepreg | 0.200 mm / 7.9 mil | Prepreg - Isola FR408HR 2113 |
| Layer 2 | 0.018 mm / 0.7 mil | Layer 2 foil, 0.5 oz Cu |
| Core | 0.991 mm / 39 mil | Core Isola FR408HR |
| Layer 3 | 0.018 mm / 0.7 mil | Layer 3 foil, 0.5 oz Cu |
| prepreg | 0.200 mm / 7.9 mil | Prepreg - Isola FR408HR 2113 |
| Bottom Copper | 0.043 mm / 1.7 mil | Layer 4 foil, 1 oz copper after plating |
| Total Stackup | 1.588 mm / 62.5 mil |
Array / Panel Information
- Coordinate with Contract Manufacturer (CM) for optimal size of this panel.
- If no feedback from CM, then produce single boards (no panel).
Fabrication Files
IPC-2581 File
| Filename | Notes |
|---|---|
| PROJECT-NAME-ipc2581.xml | IPC-2581 board information file |
Legacy PCB Files
| Filename | Notes |
|---|---|
| PROJECT-NAME-Edge_Cuts.gbr | RS274X file for the dimension (outline) layer |
| PROJECT-NAME-F_Silkscreen.gbr | RS274X file for the top silkscreen |
| PROJECT-NAME-F_Mask.gbr | RS274X file for the top soldermask |
| PROJECT-NAME-F_Cu.gbr | RS274X file for the top copper layer |
| PROJECT-NAME-In1_Cu.gbr | RS274X file for the layer 2 copper |
| PROJECT-NAME-In2_Cu.gbr | RS274X file for the layer 3 copper |
| PROJECT-NAME-B_Cu.gbr | RS274X file for the bottom copper layer |
| PROJECT-NAME-B_Mask.gbr | RS274X file for the bottom soldermask |
| PROJECT-NAME-B_Silkscreen.gbr | RS274X file for the bottom silkscreen |
| PROJECT-NAME-NPTH.drl | Excellon file for non-plated through holes |
| PROJECT-NAME-PTH.drl | Excellon file for plated through holes |
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Printed Circuit Board Assembly (PCBA) Information
Assembly Info
- All components are on the top side of the board.
- This PCBA is mostly surface mount (SMT) with a few (THT) components.
Assembly Requirements
- Assemble to IPC Class 2 or better
- Bake components that are not moisture sealed to appropriate levels as required.
- Solder paste MUST be leaded.
- Aqueous flux and wash strongly preferred.
- Clean to NASA Standard "Visibly Clean (VC)": No particles or residues are visible to the naked eye.
- No conformal coating.
- Ship in antistatic protective bag
Component Specific Assembly Information
- SMPM connectors (J3, J4) should be hand-added (there is no solder paste for their footprints).
- U1 and U28 are extremely expensive ($75 and $150 ea, respectively).
- U15 and U21 are EOL and will be supplied in cut tape form.
Assembly Files
IPC-2581 File
| Filename | Notes |
|---|---|
| PROJECT-NAME-ipc2581.xml | IPC-2581 board information file |
Bill of Materials (BOM)
| Filename | Description |
|---|---|
| PROJECT-NAME-bom.csv | BOM in Comma Separated Variable format |
Solder Paste Stencils
| Filename | Notes |
|---|---|
| PROJECT-NAME-B_Paste.gbr | RS274X file for top/front solder paste stencil |
| PROJECT-NAME-F_Paste.gbr | RS274X file for bottom/back solder paste stencil |
Mounting/Placement Location
| Filename | Description |
|---|---|
| PROJECT-NAME-3u.pos | Pick and place locations for components |