WATERPROOF SOUND-TRANSMITTING MEMBRANE, WATERPROOF SOUND-TRANSMITTING MEMBER INCLUDING SAME, ELECTRONIC DEVICE, ELECTRONIC DEVICE CASE, AND WATERPROOF SOUND-TRANSMITTING STRUCTURE

摘要

A waterproof sound-transmitting membrane of the present disclosure includes: a non-porous resin film having formed therein a plurality of through holes extending through a thickness of the non-porous resin film; and a liquid-repellent layer formed on a principal surface of the resin film and having openings at positions corresponding to positions of the plurality of through holes. The through holes have a diameter of 4.0 μm or more and 12.0 μm or less, and the waterproof sound-transmitting membrane has a through-thickness air permeability of 2.0 cm3/(cm2·second) or more and 50 cm3/(cm2·second) or less in terms of Frazier number as measured according to JIS L 1096. With this waterproof sound-transmitting membrane placed over an opening of a housing of an electronic device or the like, entry of water into the housing from outside can be prevented, in addition to which the characteristics of sound transmitted through the membrane can be kept even when the membrane has a reduced effective area.