Crack Resistant Plastic Enclosure Structures

摘要

Electronic device housing structures and other structures may be formed from molded plastic. Plastic structures such as injection molding housing structures and other structures may be provided with openings. An opening may have sidewall surfaces. Machining operations and other techniques may be used in forming the openings. Openings may be processed to enhance resistance to stress-induced cracking of the plastic structures along the sidewall surfaces. Cracking resistance may be obtained by activating the surface using heat or laser treatment and by electroplating the activated surface to form a metal liner structure. Surface treatments using applied liquid chemicals or heat may form a treated layer on the surface of an opening with enhanced cracking resistance. A plastic sleeve or other insert may form a liner structure in an opening that resists cracking. Liner structures may also be formed by applying heat or light to a coating in an opening.