Abstract: An image sensor module includes a sensing surface, a filter element and a first anti-reflective microstructure, wherein the filter element faces towards the sensing surface, and the first anti-reflective microstructure is disposed on the sensing surface. The filter element includes a substrate, an optical deposition layer structure and an optical coating layer, wherein the optical deposition layer structure is disposed on a side of the substrate away from the sensing surface, and the optical coating layer and the optical deposition layer structure are correspondingly disposed on a side of the substrate facing towards the sensing surface. The optical deposition layer structure is multilayer. An air layer is formed between the first anti-reflective microstructure and the filter element, and the first anti-reflective microstructure and the air layer partially overlap at a direction vertical to the sensing surface.

Abstract: A method for preparing a foamable composition includes the steps of: (a) mixing a first portion of polymer particles with a foaming component to obtain a foaming pre-mixture; (b) mixing a second portion of the polymer particles with a crosslinking component to obtain a crosslinking pre-mixture; and (c) mixing the foaming pre-mixture and the crosslinking pre-mixture with a third portion of the polymer particles.