PCB-assembly

HSGR PCB assembly tools

Assembly PC

Our PC runs kubuntu 23.04. It has installed https://gitlab.com/hsgr/lab/ec-placer-camera-viewer. In order to run it:

1. workon ec-palcer
2. cd Desktop/ec-placer-camera-viewer
3. python crosier.py 0 2

In the PC is connected a label printer (Direct Thermal Printing). In order to use it:

1. cd Desktop
2. workon label-printer
3. python labels.py Test

More details for python script: https://gitlab.com/librespacefoundation/qubik/qubik-org/-/snippets/2181003

Credentials:

1. user: hsgr
2. key: hsgr-lab

Stencil Printer

Our stencil printer is based on https://dengler-mechatronik.de/?p=560. In the the above photo you check the modifications:

Stencil Printer

Other Tools:

1. squeegee, use it softly and slowly as is referred in to solder paste datasheet
2. small plastic spatula or stick, to stir the solder paste
3. isopropyl alcohol and paper towel to clean everything
4. M3 allen key wrench, to install the stencil
5. Microscope Camera with USB interface, use it with VLC in order to check the alignment of PCB and stencil

Manual Pick and Place

Our Pick and Place is https://www.eurocircuits.com/blog/ec-placer/ with 2 cameras and a in-house software: https://gitlab.com/hsgr/lab/ec-placer-camera-viewer. The set-up needs 2 monitors:

1. 1st for Pick and Place cameras
2. 2nd for interactive BOM, https://github.com/openscopeproject/InteractiveHtmlBom

Pick and Place

Other Tools:

1. PCB vice: https://gitlab.com/thanos.husk/tiny-vice
2. all the grounding - ESD connections, Pick and Place and user
3. SMD feeders: https://www.thingiverse.com/thing:2414955/files
4. Base for SMD feeders (source file and *.svg file): https://cloud.libre.space/s/tLfNYMxGFto5A4Q and https://cloud.libre.space/s/A92AEf3nHW7AK86
5. Pay attention to apply ESD spray to acrylic parts
6. In the Pick and Place there are 2 dowel pins in the right side of it, there is the mounting points of SMD feeder
7. To point the current component that will be place use page marker (sticky index)

Pick and Place

Maintenance:

1. Check page 41 for YZ block, https://www.eurocircuits.com/wp-content/uploads/ec2015/ecImage/document/v20_eC-009-999-R00ManualPnPUserManual_EN_en.pdf
2. The same mechanism exists at XY block

Reflow Oven

The model of reflow oven is puhui T-962. There are some improvements base on https://github.com/UnifiedEngineering/T-962-improvements/wiki:

1. Flashing the LPC21xx controller
2. Dallas 18B20 for cold junction mod
3. Kapton tape was added for better thermal inslulation
4. Improve grounding
5. Use Custom 2 profile

Reflow Oven and Ultra sonic Cleaner

Other Tools:

1. Use M4 nuts to place PCB in to oven base

Maintenance:

1. Calibration process: https://github.com/UnifiedEngineering/T-962-improvements/wiki/calibration
2. More details for calibration: https://invent-ed.notion.site/Calibrate-Reflow-Oven-ce94fad5e4f745dfb054f108e9a41835
3. Serial port is exposed in the side of reflow oven via Dupont wires

Ultrasonic Cleaner

It is a 2.0L ultrasonic cleaner. The model is JP-010S. For flight models (space) it is not recommended to clean it with this. Use isopropyl alcohol to clean PCBs.