Reverse-engineering of Solder Mask

[Kreyren]

Issue dedicated to reverse-engineering the composition with the intention to improve it

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Solder Mask is used to cover up exposed copper tracks on a Printed Circuit Boards as shown in https://youtu.be/M3VEmBE2Nh0?t=2619 which hardens under UV light and bubbles at 300C.

Available online on e.g. https://www.hotair.cz/detail/pasty-ciny-lepidla/uv-vytvrditelny-lak-pro-nepajivou-masku-cerny.html

Expectations

1. electrically insulating liquid used to protect the copper tracks on fibreglass board.

2. Does not interfiere with SMD soldering using direct heat of +235~300 C to melt lead/tin with the use of "flux" (liquid that transfers the heat evenly and evaporates at +-280 C).

3. Doesn't react with isopropyl alcohol used in supersonic cleaner to clean the board.

Motivation

• Custom colors of PCBs
• Not economical in Europe (costs 12 USD/10 ml compared to US pricing of 0.80~2 USD) while it taking +30 days to deliver outside of europe for more economical price
  • found one for 99 CZK/5 USD that id usable after search of 4 people -> still very difficult to get one
• intended to be designed on demand for the specified use
• Full repair of https://github.com/Kreyren/kreyren/issues/86 that has been overheated which caused the mask to bubble off and expose the tracks.
• Making mistakes such as https://github.com/Kreyren/kreyren/issues/86 more idiot-proof to avoid overheating the PCB

[Kreyren]

Relevant: The solder mask is pressumably a photopolymer (https://en.wikipedia.org/wiki/Photopolymer)