Patent ID: 9636616
Date: 2017-05-02
CPC Classifications: B01D,B32B,H05K

Claim:
1. A water-proof air-permeable filter for ensuring ventilation and also preventing entry of water, the water-proof air-permeable filter comprising: a non-porous resin film having opposed first and second surfaces spaced from each other in a thickness direction, the resin film having formed therein a plurality of through pores extending through the resin film in the thickness direction of the resin film; and a treated layer having hydrophobicity and oil repellency, and formed on at least one of the first and second surfaces of the resin film such that the treated layer has openings at positions corresponding to the plurality of through pores, wherein a ratio of a standard deviation of a size of the through pores relative to an average of the size of the through pores is 10% or less.