Transcription Characteristics of Mold Surface Topography in the Molding of Aspherical Glass Lenses

Abstract

The transcription characteristics of the mold surface in the molding of aspherical glass lenses for camera phone modules have been investigated experimentally. The surface topographies of both the form and the roughness were compared between the mold and the molded lens. For the form topography, the molded lens showed a transcription ratio of 93.4% against the mold, which is obtained by comparing the form error (PV) values of the mold and the molded lens. The transcription characteristics of the roughness topography were ascertained by bearing ratio analysis.

Wafer-level Fabrication of Ball Lens by Cross-cut and Reflow of Wafer-bonded Glass on Silicon

“…However, glass provides better mechanical, thermal, and chemical properties than the polymer. Therefore, various attempts to produce glass micro-lenses have been studied, although most of these methods produce hemispherical lenses [5][6][7][8][9]. Still, the mushroom-shaped or nearly spherical glass lens has not been reported, especially, for wafer-level application.…”

“…In such packaging, a ball lens is one of the crucial elements relaying light between the edgeemitting components. To date, various ways of producing a micro lens at wafer-level such as thermal reflow of photoresist [4], glass [5], sol-gel glass [6], vacuum-reflow of glass [7], or molding [8,9], have been reported. However, most of these methods produce hemispherical lenses relaying light normal to the wafer, in other words, to surface-sensitive devices such as PDs (photodiode) or VCSELs (vertical cavity surface emitting laser) that are attached to the wafer.…”