Filter membrane

Patent metadata

Field	Value
Publication number	US-2019232218-A1
Application number	US-201916260495-A
Country	US
Kind code	A1
Filing date	Jan 29, 2019
Priority date	Jan 30, 2018
Publication date	Aug 1, 2019
Grant date	—

Abstract

A filter membrane includes a membrane having through holes that selectively separates specific material in processing medium, the membrane including first, second and third layers such that the first layer has first surface that is supplied with processing medium, the third layer has second surface on the opposite side of the first surface, and the second layer is formed between the first and third layers. The first layer includes first convex and concave portions, the third layer includes second convex and concave portions each having a larger area than each first concave portion, the second convex portions are formed to surround the second concave portions and connected to one another, the second layer has through holes connecting the second concave portions and first set of the first concave portions, and the first concave portions include second set in regions opposing the second convex portions that is connected to each other.

First claim

What is claimed is:

1 . A filter membrane, comprising:
a membrane having a plurality of through holes configured to selectively separate a specific material from other materials in a processing medium, the membrane comprising a first layer, a second layer and a third layer formed such that the first layer has a first surface configured to be supplied with the processing medium, the third layer has a second surface on an opposite side with respect to the first surface of the first layer, and the second layer is formed between the first layer and the third layer, wherein the first layer includes a plurality of first convex portions and a plurality of first concave portions formed such that each of the first convex portions is formed from an interface between the second layer and the first layer toward the first surface of the first layer and has a cross-sectional area parallel to the first surface gradually decreasing toward the first surface of the layer, and that each of the first concave portions has a bottom at the interface between the second layer and the first layer, the third layer includes a plurality of second convex portions and a plurality of second concave portions formed such that each of the second convex portions is formed from an interface between the second layer and the third layer toward the second surface and has a cross-sectional area parallel to the second surface gradually decreasing toward the second surface, and that each of the second concave portions has a bottom at the interface between the second layer and the third layer and has a larger area than each of the first concave portions, the third layer is formed such that the second convex portions are formed to surround the second concave portions and connected to one another, the second layer has a plurality of through holes connecting the second concave portions and a first set of the first concave portions, and the first concave portions includes a second set of the first concave portions formed in regions opposing the second convex portions such that the second set of the first concave portions in each of the regions is connected to each other.

2 . The filter membrane according to claim 1 , wherein the membrane is formed of a same material such that the first layer, the second layer and the third layer are integrally formed.

3 . The filter membrane according to claim 1 , wherein the plurality of the second convex portions foul's the second surface of the third layer in a honeycomb shape.

4 . The filter membrane according to claim 1 , wherein the plurality of the second convex portions forms the second surface of the third layer in a lattice shape.

5 . The filter membrane according to claim 1 , wherein the first layer is formed such that each of the first convex portions has a cross-sectional shape perpendicular to the first surface such that an angle formed by a wall surface of each of the first convex portions and the first surface is in a range of 43 to 80 degrees.

6 . The filter membrane according to claim 1 , wherein the third layer is formed such that each of the second convex portions has a cross-sectional shape perpendicular to the second surface such that an angle formed by a wall surface of each of the second convex portions and the second surface is in a range of 43 to 80 degrees.

7 . The filter membrane according to claim 1 , wherein the second layer is formed such that a diameter of each of the through holes connecting the first concave portions and the second concave portions is in a range of 0.1 to 1.0 μm.

8 . The filter membrane according to claim 1 , wherein the third layer is formed such that a thickness of each of the second convex portions is greater than a total thickness of the first layer and the second layer.

9 . The filter membrane according to claim 1 , wherein the membrane is formed such that a total thickness of the first layer, the second layer and the third layer is 15 μm or less.

10 . The filter membrane according to claim 1 , wherein the first layer and the third layer are formed such that a ratio of an area of the first surface formed by the first convex portions per unit area to an area of the second surface formed by the second convex portions per unit area is in a range of 50 to 90%.

11 . The filter membrane according to claim 1 , wherein the first layer and the third layer are formed such that a ratio of a total area a 1 of the first surface formed by the first convex portions to a total area A of the membrane is in a range of 20 to 50%.

12 . The filter membrane according to claim 1 , wherein the first layer and the third layer are formed such that a ratio of a total area b 1 of the second surface formed by the second convex portions to a total area A of the membrane is in a range of 50 to 70%.

13 . The filter membrane according to claim 2 , wherein the plurality of the second convex portions forms the second surface of the third layer in a honeycomb shape.

14 . The filter membrane according to claim 2 , wherein the plurality of the second convex portions forms the second surface of the third layer in a lattice shape.

15 . The filter membrane according to claim 2 , wherein the first layer is formed such that each of the first convex portions has a cross-sectional shape perpendicular to the first surface such that an angle formed by a wall surface of each of the first convex portions and the first surface is in a range of 43 to 80 degrees.

16 . The filter membrane according to claim 2 , wherein the third layer is formed such that each of the second convex portions has a cross-sectional shape perpendicular to the second surface such that an angle formed by a wall surface of each of the second convex portions and the second surface is in a range of 43 to 80 degrees.

17 . The filter membrane according to claim 2 , wherein the second layer is formed such that a diameter of each of the through holes connecting the first concave portions and the second concave portions is in a range of 0.1 to 1.0 μm.

18 . The filter membrane according to claim 2 , wherein the third layer is formed such that a thickness of each of the second convex portions is greater than a total thickness of the first layer and the second layer.

19 . The filter membrane according to claim 2 , wherein the membrane is formed such that a total thickness of the first layer, the second layer and the third layer is 15 μm or less.

20 . The filter membrane according to claim 2 , wherein the first layer and the third layer are formed such that a ratio of an area of the first surface formed by the first convex portions per unit area to an area of the second surface formed by the second convex portions per unit area is in a range of 50 to 90%.

Assignees

• Ibiden Co Ltd

Inventors

• Kunieda Masatoshi
• Higashi Hirokazu
• Kawai Tatsuhiro

Classifications

• B01D2239/065

  More than one layer present in the filtering material · CPC title

• B01D39/1692

  Other shaped material, e.g. perforated or porous sheets · CPC title

• B01D2325/08

  Patterned membranes · CPC title

• B01D69/02

  characterised by their properties · CPC title

• B01D53/228 Primary

  characterised by specific membranes · CPC title