Elevating smartphone middle frame performance, appearance and manufacturability

SABIC, a global leader in the chemical industry, has recently introduced ULTEM™ DU762 resin, a specialty thermoplastic whose design, manufacturing and system cost advantages over metal make it well suited for smartphone middle frame applications. This new, innovative ULTEM resin, compatible with non-conductive physical vapor deposition (PVD) sputtering processes, provides a high-gloss, metallic surface to enhance the appearance of smartphones. This polyetherimide (PEI) material also features excellent chemical resistance for durability, light weight for usability, and a balance of ductility and strength for structural parts.

“Consumers choosing top-of-the-line smartphones demand premium materials that complement cutting-edge technologies, such as artificial intelligence (AI),” said Sergi Monros, vice president, Specialties business unit, SABIC. “Our new ULTEM DU762 resin offers high quality without the drawbacks of traditional materials. It delivers great value through design flexibility and streamlined production while meeting rigorous standards for aesthetics and performance. As smartphone styling and capabilities advance, SABIC remains aligned with the evolving needs of the consumer electronics industry.”

Compared to titanium, stainless steel and aluminum, which require time-consuming machining, the new ULTEM grade can be cost-effectively manufactured using high-speed, high-volume injection molding. It is also much lighter than metal options. Furthermore, as a non-conductive, metallized polymer, the SABIC resin eliminates the need for an unsightly antenna split in the middle frame. Using metal frames with plastic antenna splits can create a non-uniform appearance that impacts styling.

Another incumbent frame material, glass fiber-reinforced polycarbonate (PC) resin, typically uses non-conductive vacuum metallization (NCVM). This multi-layer process creates a thick coating that can accumulate along edges and corners, preventing a clean, sharp line. In contrast, PVD metallization is simpler and produces a much thinner profile. Furthermore, glass fiber in the PC resin can migrate, creating an uneven surface that affects gloss. Unreinforced ULTEM DU762 resin ensures a smooth, high-gloss finish and resists abrasion and cracking better than softer PC resins.

Additional features of ULTEM DU762 resin include high heat resistance and robust resistance to sunscreen and other chemicals. ULTEM DU762 resin is available globally.

Picture source: SABIC