Imaging device and its manufacturing method

• US 20070030334A1
• Filed: 05/26/2004
• Published: 02/08/2007
• Est. Priority Date: 05/30/2003
• Status: Active Grant

• Current Assignee: PANASONIC AUTOMOTIVE SYSTEMS CO., LTD. (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Nishizawa, Hiroshi
• Granted Patent: US 7,534,059 B2
• Time in Patent Office: Days
• US Class Current: 347/245
• CPC Class Codes: H04N 23/52 Elements optimising image sensor operation, e.g. for electromagnetic interference [EMI] protection or temperature control by heat transfer or cooling elements
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices

Abstract

An imaging apparatus includes: a three-dimensional substrate in which a partition wall (11) having an opening (10a) at a central portion is formed so as to cross an inner cavity; an optical filter (5) that is fixed on a first flat surface (12) of both surfaces of the partition wall so as to cover the opening; a semiconductor imaging device (4) that is face-down mounted on a second flat surface (13) of the partition wall with an imaging area (4a) facing the opening; and an optical system for forming images that is installed on a side of the optical filter in the inner cavity of the three-dimensional substrate. The opening of the partition wall is dosed on both sides with the optical filter and the semiconductor imaging device so as to form a cavity. An air passage (12a) for allowing communication between the cavity and an exterior of the three-dimensional substrate is formed on the first flat surface, and has a labyrinth structure that causes a flow rate of air passing through the air passage to vary depending on a location in the air passage. This allows air circulation between the exterior and a cavity enclosed by a semiconductor imaging device and an optical filter, while suppressing the entry of foreign matter from the exterior into the cavity via an airflow caused by expansion/contraction of air.

Claims

1. An imaging apparatus, comprising:

a three-dimensional substrate in which a partition wall having an opening at a central portion is formed so as to cross an inner cavity;

an optical filter that is fixed on a first flat surface of both surfaces of the partition wall so as to cover the opening;

a semiconductor imaging device that is face-down mounted on a second flat surface of the partition wall with an imaging area facing the opening; and

an optical system for forming images that is installed on a side of the optical filter in the inner cavity of the three-dimensional substrate,

the opening of the partition wall being closed on both sides with the optical filter and the semiconductor imaging device so as to form a cavity,

wherein an air passage for allowing communication between the cavity and an exterior of the three-dimensional substrate is formed on the first flat surface, and has a labyrinth structure that causes a flow rate of air passing through the air passage to vary depending on a location in the air passage.

2. The imaging apparatus according to claim 1,

wherein the labyrinth structure of the air passage is defined by a zigzag shape, a shape inclined as a whole or a circular-arc shape.

3. The imaging apparatus according to claim 1,

wherein the labyrinth structure of the air passage is formed by providing a rib crossing the air passage so that a height of the air passage in a thickness direction of the optical filter varies along a flow direction of the air passage.

4. The imaging apparatus according to claim 1,

wherein the labyrinth structure of the air passage is formed by providing a concave part on a side edge of the air passage so that a width of the air passage within the first flat surface varies along the flow direction of the air passage.

5. The imaging apparatus according to claim 1,

wherein the three-dimensional substrate has such a low light transmittance with respect to a region sensitive to light reception by the semiconductor imaging device that substantially no unwanted signal is generated.

6. The imaging apparatus according to claim 1,

wherein the air passages are located at a position axisymmetric with respect to the opening in the three-dimensional substrate.

7. A method for manufacturing an imaging apparatus that uses a three-dimensional substrate in which a partition wall having an opening at a central portion is formed so as to cross an inner cavity, an air passage with a non-linear structure for allowing communication between the opening and an exterior of the three-dimensional substrate is formed on a first flat surface of both surfaces of the partition wall, and a conductor land for connection is provided on a second flat surface of the partition wall, comprising process steps of:

fixing an optical filter on the first flat surface by bonding;

installing a semiconductor imaging device with respect to the conductor land for connection provided on the second flat surface;

sealing the semiconductor imaging device; and

subsequently installing an optical system for forming images in the inner cavity of the three-dimensional substrate.