providing a substrate with curved surface; said substrate at least comprising a transparent hard plastic material and having an outer surface and an inner surface opposite to the outer surface; wherein the substrate has a curved surface at least at an outer rim area of the inner surface;

applying primer layer; by using a coating process, a primer layer being applied to said outer rim area of the inner surface of the plastic plate;

applying sealing ring layer; by using a glue dispensing process, at least one sealing ring layer being provided on the primer layer; said at least one sealing ring layer being extending in a ring shape around the outer rim area of the inner surface of the substrate having the primer layer; and

insert-molding injection of connecting structure; through an insert-molding injection process, a connecting structure being formed in an insert-molding injection manner and fixed at a position of the outer rim area of the plastic plate having the primer layer; wherein the connecting structure has an L-shaped structure in sectional view and is configured to connect an external component, such that the substrate is capable of connecting with the external component through the connecting structure;

wherein, in the process of insert-molding injection of connecting structure, the primer layer is for providing an adhesion effect between the substrate and the connecting structure, in addition, said at least one sealing ring layer is for improving a sealing effect between the substrate and the connecting structure; said at least one sealing ring layer is disposed on a surface of the primer layer facing the connecting structure, such that the sealing ring layer is sandwiched between and fully covered by adjoining surfaces of the primer layer and the connecting structure after the process of insert-molding injection of connecting structure.