The manufacturing of a surface anchor structure for the electroless plating of a three-dimensional antenna integrated with a mobile device case

Abstract

This study proposes a method to improve the manufacturing process of a surface anchor structure for the injection molding along with bonding properties of the plating layer for antennas, which can be applied to the Laser Direct Plating (LDP) process for the production of a three-dimensional antenna integrated with a mobile device case. By adjusting parameters such as the output of the laser processing, scanning speed, and pulse recurrence frequency, a micro anchor structure was developed on the surface of the injection mold. The measurement of the surface roughness using a 3D surface profiler showed that the roughness improved by approximately 3.6 times, from 0.96 to 3.24 µm. In addition, the zigzag arrangement of the micro anchor structure was improved by 1.2 times compared to the even arrangement. Furthermore, if the micro anchor structure contained a wall after laser processing, the bonding strength of the plating solution was 69%; with no wall, it was 94% or higher. Thus, the existence of walls resulted in a difference of 1.4 times in the bonding strength. The laser processing improved the bonding strength of the plating solution on the micro anchor structure by approximately 19 times.