Is the Teensy 4.0 Lockable module compatible with aqueous cleaning?

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1

We are using the Teensy 4.0 Lockable module (DEV-28368) in a production PCB assembly process.

After soldering, our assemblies are normally cleaned in an inline aqueous jet-cleaning machine using deionized water and water-based chemistry, followed by hot-air drying.

Before introducing this process into production, we would like to know whether the Teensy 4.0 Lockable module is compatible with aqueous cleaning.

Specifically:

  • Has the module been qualified for aqueous jet cleaning?
  • Are there any restrictions regarding cleaning temperature, pressure, chemistry, or drying conditions?
  • Are there any components on the module (USB connector, push button, MCU, crystal, etc.) that should be protected from cleaning?
  • Is there any official manufacturing guidance available regarding washing and drying of the module?

Thank you for your assistance.

2

So, I won’t be able to give a definitive answer but I can offer some insights/info and things to note to keep it as safe a process as can be. In general if your process is successful when using similar PCBs it will likely be fine…though if switching the cleaning fluid to IPA is an option it might work better

  • Pressure: Use the minimum effective jet pressure; you want to reduce the risk of forcing fluid into the USB connector and push button (these have larger surface areas, more risk of corrosion if left wet)

  • Chemistry: Ensure your solution is compatible with PCBs/solder masking, components, and any exposed metal (gold, tin, nickel)

  • Drying: Ensure your hot-air drying cycle is thorough/complete. The PJRC forum has a reference suggesting ~80 °C for 15 minutes should work well in a static oven as a useful baseline, but inline hot-air drying may require adjusted time/velocity to ensure no trapped moisture remains under the components

  • Orientation: If possible, orient the board to allow water to drain away from the USB connector and push button

I’d advise testing with one or two units to start with; run a trial lot and perform functional testing (including USB communication and button programming) after cleaning and drying them and adjust if needed