HDLG-3416 Dot Matrix Display Module color changed after cleansing and coating

When applying cleansing and coating materials to the Dot Matrix Display Module HDLG-3416 after assembling it onto the PCB, the color of the display changed to white. Liquids used were Nexier, IPA (isopropyl alcohol) and 1A33 conformal coating

Can these cleansing liquid or coatings chemically affect the part?

Yes, either or both of these, cleansing and coating, have affected the display module.

DI water is recommended for cleansing this type of parts, as there are some chemicals that do not work well with PC material of the plastic lens.

However, if one needs to use a cleaning chemical, its chemical resistance should be checked first. A table for different type of chemicals on different types of surfaces is attached here for reference:
Plastic Resin’s Chemical Resistance Table.pdf (30.9 KB)

Applicable Part Number