After the mold has been used for a period of time, a large amount of epoxy and release agent remain on the surface, which is very difficult to remove due to long-term curing at high temperature.

Use micro-dust cleaner PTC-13, 60℃, ultrasonic (40KHz, 50W/L), soak and clean for 10 minutes.
The residue was found to have softened slightly and some of the residue had fallen off.

Use micro-dust cleaner PTC-13, 60℃, ultrasonic (40KHz, 50W/L), soak and clean for 20 minutes.
The residue was found to have softened slightly and most of the residue had come off.

Use micro-dust cleaner PTC-13, 60℃, ultrasonic (40KHz, 50W/L), soak and clean for 20 minutes. Then use a nylon short-bristled brush to remove. It was found that most of the residue had been removed.

Use micro-dust cleaner PTC-13, 60℃, ultrasonic (40KHz, 50W/L), soak and clean for 30 minutes. Then use a nylon short-bristled brush to remove. It was found that the residue on the mold had been completely removed.

Before the oscillator wafer SU8 photoresist is removed, the SU8 photoresist is pre-baked at 120°C for 12 minutes, and then baked on a heating plate at 170+-10°C for 60 minutes.

Put this wafer in 80+-10℃, PTC13 dust cleaning agent, soak for 120 minutes.

Take it out and find that the hardened SU8 has swollen and can be easily scraped off with a plastic straw.

Take it out and find that the hardened SU8 has swollen and can be easily scraped off with a plastic straw.

Conclusion and suggested process:

5.1 Micro dust cleaning agent PTC13 can also remove hardened SU8 photoresist.
5.2 Micro dust cleaning agent PTC13 is a strong alkaline hardened resin stripper. It is not recommended to use if there is aluminum/magnesium/zinc/ITO structure on the wafer.