Color sensor for vehicle and method for manufacturing the same

• US 20080067330A1
• Filed: 08/14/2007
• Published: 03/20/2008
• Est. Priority Date: 09/19/2006
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yamamoto, Atsushi
• Application Number:
  US11/889,534
• Publication Number:
  US 20080067330A1
• Time in Patent Office: Days
• US Class Current: 250/226
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: H01L 27/14621 Colour filter arrangements
• CPC Class Codes: H01L 27/14645 Colour imagers
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 27/14649 Infrared imagers
• CPC Class Codes: H01L 27/14652 Multispectral infrared imagers, having a stacked pixel-element structure, e.g. npn, npnpn or MQW structures
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements

Abstract

A color sensor includes: a substrate; first to third light receiving elements on the substrate; a red light filter for passing a red light and a first near infrared light block filter for blocking a near infrared light on the first light receiving element; a green light filter for passing a green light and a second near infrared light block filter on the second light receiving element; a visible light block filter for blocking a visible light on the third receiving element; and an ultraviolet light block plate disposed over the first and second near infrared light block filters and the visible light block filter.

Claims

1. A color sensor comprising:

a substrate;

first to third light receiving elements disposed on a surface of the substrate, wherein each of the first to third light receiving elements outputs an electric signal corresponding to an amount of light in an ultraviolet light range, a visible light range and a near infrared light range;

a red light filter for selectively passing a red light;

a first near infrared light block filter for blocking a near infrared light, wherein the first near infrared light block filter and the red light filter are disposed on the first light receiving element in this order;

a green light filter for selectively passing a green light;

a second near infrared light block filter for blocking the near infrared light, wherein the second near infrared light block filter and the green light filter are disposed on the second light receiving element in this order;

a visible light block filter for blocking a visible light, wherein the visible light block filter is disposed on the third receiving element; and

an ultraviolet light block plate disposed over the first and second near infrared light block filters and the visible light block filter.

2. The sensor according to claim 1, wherein

the first near infrared light block filter is disposed under the ultraviolet light block plate, and

the second near infrared light block filter is disposed under the ultraviolet light block plate.

3. The sensor according to claim 1, further comprising:

an adhesive member disposed between the substrate and the ultraviolet light block plate, wherein

the adhesive member is made of visible light curing adhesive.

4. The sensor according to claim 1, further comprising:

a fourth light receiving element disposed on the surface of the substrate;

a blue light filter for selectively passing a blue light; and

a third near infrared light block filter for blocking the near infrared light, wherein

the third near infrared light block filter and the fourth light receiving element are disposed on the fourth light receiving element, and

the ultraviolet light block plate is further disposed over the third near infrared light block filter.

5. The sensor according to claim 1, further comprising:

a fifth light receiving element disposed on the surface of the substrate, wherein

the fifth light receiving element is capable of receiving light through the ultraviolet light block plate without passing the light through the red and green light filters, the first and second near infrared light block filters and the visible light block filter.

6. The sensor according to claim 1, wherein

the first near infrared light block filter is made of a thin film,

the second near infrared light block filter is made of another thin film, and

the visible light block filter is made of further another thin film.

7. A method for manufacturing the color sensor according to claim 6, the method comprising:

arranging the first to third light receiving elements on the substrate;

forming the red light filter on the first light receiving element, and forming the green light filter on the second light receiving element;

forming a SOG film on a whole surface of the substrate including the red and green light filters; and

forming a thin film on the SOG film and patterning the thin film for providing the first and second near infrared light block filters; and

forming another thin film on the SOG film and patterning the another thin film for providing the visible light block filter.

8. The method according to claim 7, wherein

the forming the red light filter and the forming the green light filter includes:

forming an electrode pad on the substrate, the method further comprising;

removing a part of the SOG film disposed on the electrode pad so that the electrode pad is exposed from the SOG film after the forming the thin film and the forming the another thin film.

9. The method according to claim 7, wherein

the forming the thin film on the SOG film is performed by a vapour deposition process.

10. The method according to claim 7, wherein

the forming the another thin film on the SOG film is performed by a vapour deposition process.

11. A color sensor comprising:

a silicon substrate having a first conductive type;

a first impurity diffusion region having a second conductive type and disposed on a surface portion of the substrate;

a second impurity diffusion region having the first conductive type and disposed on a surface portion of the first impurity diffusion region; and

a third impurity diffusion region having the second conductive type and disposed on a surface portion of the second impurity diffusion region, wherein

a boundary between the first impurity diffusion region and the substrate provides a first PN junction for photoelectric converting a near infrared light at the first PN junction,

a boundary between the second impurity diffusion region and the first impurity diffusion region provides a second PN junction for photoelectric converting a red light at the second PN junction, and

a boundary between the third impurity diffusion region and the second impurity diffusion region provides a third PN junction for photoelectric converting a green light at the second PN junction.

12. The sensor according to claim 11, further comprising:

a fourth impurity diffusion region having the first conductive type and disposed on a surface portion of the third impurity diffusion region, wherein

a boundary between the fourth impurity diffusion region and the third impurity diffusion region provides a fourth PN junction for photoelectric converting a blue light at the second PN junction.

13. A color sensor comprising:

a color image element including a substrate, a plurality of light receiving elements and a color filter, wherein each light receiving element is disposed on a surface of the substrate, and the color filter is disposed over the plurality of light receiving elements, and wherein each light receiving element outputs an electric signal corresponding to amount of light;

a lead frame, on which the color image element is disposed;

a bonding wire for electrically bonding the color image element and the lead frame;

a ultraviolet light block plate for blocking an ultraviolet light and made of glass, wherein the ultraviolet light block plate is bonded to a light receiving surface of the color image element with a visible light curing adhesion member; and

a resin mold for molding the bonding wire and the color image element other than the light receiving surface of the color image element.

14. The sensor according to claim 13, wherein

the ultraviolet light block plate has a light transmission rate of a light wavelength equal to or smaller than 350 nm, and

the light transmission rate is equal to or smaller than 10%.

15. The sensor according to claim 14, wherein

the light transmission rate of the ultraviolet light block plate is equal to or smaller than 1%.

16. The sensor according to claim 13, wherein

the bonding wire has a bonding portion to the substrate, and

the bonding portion is covered with the visible light curing adhesion member.

17. A method for manufacturing the color sensor according to claim 13, the method comprising:

mounting the color image element on the lead frame;

electrically coupling the color image element and the lead frame with the bonding wire;

bonding the ultraviolet light block plate to the light receiving surface of the color image element with the visible light curing adhesion member; and

sealing the bonding wire and the color image element other than the light receiving surface of the color image element with the resin mold by using a metal die, wherein

the visible light curing adhesion member has a thickness, which is larger than a diameter of a particle in atmosphere in the bonding the ultraviolet light block plate.

18. The method according to claim 17, wherein

the thickness of the visible light curing adhesion member is equal to or larger than 10 microns.

19. A color sensor comprising:

a color image element including a substrate, a plurality of light receiving elements and a color filter, wherein each light receiving element is disposed on a surface of the substrate, and the color filter is disposed over the plurality of light receiving elements, and wherein each light receiving element outputs an electric signal corresponding to amount of light;

a lead frame, on which the color image element is disposed;

a bonding wire for electrically bonding the color image element and the lead frame;

a transparent resin mold for molding the bonding wire and the color image element; and

a ultraviolet light block filter for blocking an ultraviolet light, wherein the ultraviolet light block filter is disposed on the transparent resin mold over a light receiving surface of the color image element.

20. The sensor according to claim 19, wherein

the transparent resin mold has an upper surface, which is flat, and

the ultraviolet light block filter is disposed on the upper surface of the transparent resin mold.

21. A color sensor comprising:

a color image element including a substrate, a plurality of light receiving elements and a color filter, wherein each light receiving element is disposed on a surface of the substrate, and the color filter is disposed over the plurality of light receiving elements, and wherein each light receiving element outputs an electric signal corresponding to amount of light;

a lead frame, on which the color image element is disposed;

a bonding wire for electrically bonding the color image element and the lead frame;

a ultraviolet light block filter for blocking an ultraviolet light, wherein the ultraviolet light block filter is disposed on a light receiving surface of the color image element through a SOG film; and

a resin mold for molding the bonding wire and the color image element other than the light receiving surface of the color image element.

22. The sensor according to claim 21, wherein

the ultraviolet light block filter is made of a thin film.