Surface treatment method for casing

A surface treatment method for a casing, the casing having an outer surface and four sidewalls surrounding the outer surface, the surface treatment method comprising:

• forming a heat transferring film on the casing by a vacuum heat transfer process or a paint-drying process, the heat transferring film covering the outer surface and the four sidewalls;
• wherein the process of forming the heat transferring film on the casing further comprises:
• a heat pressing layer and a releasing film layer attached to a surface of the heat pressing layer;
• forming the heat transferring film on the casing under heat and vacuum pressure using a heat pressing machine, with the heat pressing layer being attached to the casing;
• and
• removing the releasing film layer of the heat transferring film to expose the heat pressing layer;
• and
• forming a surface pattern layer on a portion of the heat transferring film facing away from the outer surface by a digital inkjet curable by ultraviolet light.