For example, the second coupling area 272 may include the first metal part 210, the second metal part 220, the first adhesive layer 261, the second portion 232 of the polymer part 230, and the second adhesive layer 262. For example, the second coupling area 272 may be formed in a position adjacent to the second portion 232 of the polymer part 230. For example, referring to
In various embodiments, the second coupling area 272 may include the first adhesive layer 261 and the second adhesive layer 262. For example, an adhesive material may be chemically bonded with metal atoms and polymer molecules to provide a coupling force stronger than that in the first coupling area 271.
Although the second coupling area 272 is illustrated as including both the first adhesive layer 261 and the second adhesive layer 262, the second coupling area 272 is not necessarily limited thereto. For example, the second coupling area 272 may include one of the first adhesive layer 261 and the second adhesive layer 262. For example, the second coupling area 272 may include the first adhesive layer 261 for bonding the first metal part 210 and the polymer part 230 and may not include the second adhesive layer 262.