Nano Injection Molding Process for Smartphone Glass Cover Plates

For smartphone products, assembling glass cover plates often faces challenges such as uneven gaps between the glass and the frame and glue overflow. The industry commonly uses a glue‑dispensing plus CCD alignment process, which is simple but increases glue usage, material costs, and assembly expenses. With the trend toward narrow bezels, manufacturers have adopted a complex combination of five‑axis glue dispensing, CCD alignment, and multi‑stage wiping, which further raises equipment, glue, and labor costs while still yielding a high defect rate.

To address these issues, a nano‑injection molding solution for glass cover plates has been developed. This approach uses a high‑polymer material that can etch nano‑holes on the glass surface, allowing the injected plastic to bond tightly with the glass during molding, thus preventing separation in reliability tests and achieving an integrated, one‑piece structure.

The process features include first printing an ink layer on one side of the glass, then applying a nano‑coating on the ink layer and the glass edges. The treated glass plate is placed into an injection mold, where high temperature causes the glass and plastic to bond, forming a single structural component.

The implementation steps are: (i) cut, grind, and temper the glass to serve as raw material; (ii) print ink on the processed glass and cure it; (iii) apply the nano‑coating on the inked surface and glass edges, allowing it to settle under suitable temperature; (iv) place the semi‑finished glass into the injection mold and perform plastic injection, adjusting pressure and temperature to create a unified component.

By using this nano‑injection molding process, the glass cover plate is formed in a single step, effectively solving uneven gaps and glue overflow, reducing glue and assembly costs, and providing a cost‑effective alternative to the five‑axis glue‑dispensing and CCD alignment methods, especially for ultra‑narrow bezel designs.