Two-dimensional image detector and process for manufacturing the same

• US 6,262,408 B1
• Filed: 01/13/1999
• Issued: 07/17/2001
• Est. Priority Date: 01/20/1998
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Shimadzu Corporation
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Shimadzu Corporation
• Inventors: Sato, Toshiyuki, Tokuda, Satoshi, Izumi, Yoshihiro, Shinomiya, Tokihiko, Teranuma, Osamu
• Primary Examiner(s): Epps, Georgia
• Assistant Examiner(s): Thompson, Timothy J
• Application Number:
  US09/229,269
• Time in Patent Office: 916 Days
• Field of Search: 250/208.1, 250/370.01, 250/370.08, 250/370.09, 250/370.12, 250/370.13
• US Class Current: 250/208.1
• CPC Class Codes: H01L 27/14676 X-ray, gamma-ray or corpuscular radiation imagers measuring X-, gamma- or corpuscular radiation G01T1/00
• CPC Class Codes: H01L 2924/351 Thermal stress

Abstract

A two-dimensional image detector of the present invention includes: an active matrix substrate equipped with charge storage capacitors and TFTs; and an opposing substrate equipped with a semiconductor substrate. The two-dimensional image detector is formed by adhering the active matrix substrate and the opposing substrate to each other with an anisotropic conductive adhesive agent. With this structure, since a semiconductor layer is not required to be deposited on the active matrix substrate where the TFTs are already formed, it is possible to use CdTe, CdZnTe, etc. The use of CdTe, CdZnTe, etc. as a material of the semiconductor layer having photoconductivity allows the two-dimensional image detector to show good response and to deal with the dynamic images.

Claims

1. A two-dimensional image detector comprising:

an active matrix substrate including switching elements and charge storage capacitors having respective pixel electrodes connected to the switching elements;

an opposing substrate including an electrode layer and a semiconductor layer having photoconductivity, said active matrix substrate and said opposing substrate being disposed so that the charge storage capacitors face the semiconductor layer;

a connection layer, disposed between said substrates, for connecting said substrates to each other; and

wherein said connection layer has conductivity in only a direction normal to a surface of the charge storage capacitor or the semiconductor layer, where the charge storage capacitor faces the semiconductor layer.

2. The two-dimensional image detector as set forth in claim 1,

wherein said semiconductor layer is made of a crystalline or polycrystalline material, and has excellent sensitivity to X-rays.

3. The two-dimensional image detector as set forth in claim 2,

wherein said semiconductor layer is made of a compound semiconductor represented by CdTe or CdZnTe.

4. The two-dimensional image detector as set forth in claim 1,

wherein said opposing substrate includes connection electrodes on the semiconductor layer, and each of said connection electrodes is located so as to face the pixel electrode of said active matrix substrate.

5. The two-dimensional image detector as set forth in claim 4,

wherein the pixel electrode has a smaller area than the connection electrode.

6. The two-dimensional image detector as set forth in claim 1,

wherein said opposing substrate includes a charge blocking layer on said semiconductor layer, for blocking a flow of charges from one surface of said charge blocking layer.

7. The two-dimensional image detector as set forth in claim 6,

wherein said opposing substrate includes connection electrodes on said charge blocking layer, and each of said connection electrodes is located so as to face the pixel electrode of said active matrix substrate.

8. The two-dimensional image detector as set forth in claim 1,

wherein said opposing substrate includes a charge blocking layer between the electrode layer and the semiconductor layer.

9. The two-dimensional image detector as set forth in claim 1,

wherein said connection layer includes an insulating adhesive agent and conductive particles dispersed in said adhesive agent, and has anisotropic conductivity.

10. The two-dimensional image detector as set forth in claim 9,

wherein said adhesive agent has a thermosetting property.

11. The two-dimensional image detector as set forth in claim 9,

wherein said adhesive agent has thermoplasticity.

12. The two-dimensional image detector as set forth in claim 9,

wherein said adhesive agent has a photo-curing property.

13. The two-dimensional image detector as set forth in claim 9,

wherein said connection layer is in a paste form.

14. The two-dimensional image detector as set forth in claim 9,

wherein said connection layer is in a film form.

15. The two-dimensional image detector as set forth in claim 1,

wherein said semiconductor layer is also used as a support substrate of said opposing substrate.

16. The two-dimensional image detector as set forth in claim 4,

wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

17. The two-dimensional image detector as set forth in claim 7,

wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

18. The two-dimensional image detector as set forth in claim 1,

wherein protrusion electrodes are provided on said pixel electrodes.

19. The two-dimensional image detector as set forth in claim 1,

wherein said semiconductor layer has photoconductivity with respect to radiation.

20. The two-dimensional image detector as set forth in claim 1,

wherein said semiconductor layer has photoconductivity with respect to visible light or infrared light, and permeability with respect to visible light or infrared light.

21. A process for manufacturing a two-dimensional image detector, comprising the steps of:

(a) preparing an active matrix substrate including switching elements and charge storage capacitors having pixel electrodes;

(b) preparing an opposing substrate including an electrode layer and a semiconductor layer showing photoconductivity; and

(c) adhering said active matrix substrate and said opposing substrate to each other with a connection layer having anisotropic conductivity.

22. The process for manufacturing the two-dimensional image detector as set forth in claim 21,

wherein, in said step (c), an anisotropic conductive adhesive agent including conductive particles dispersed in an adhesive agent is used as said connection layer, and applied or transferred to either said active matrix substrate or said opposing substrate.

23. The process for manufacturing the two-dimensional image detector as set forth in claim 22,

wherein, in said step (c), said anisotropic conductive adhesive agent is applied or transferred to have a thickness substantially equal to a diameter of said conductive particle.

24. The process for manufacturing the two-dimensional image detector as set forth in claim 22,

wherein, in said step (c), a thermosetting-type or thermoplastic-type anisotropic conductive adhesive agent is used as said anisotropic conductive adhesive agent, and

said active matrix substrate and said opposing substrate which are disposed so as to face each other are passed between a pair of heat rollers, and adhered to each other by heat and pressure.

25. The process for manufacturing the two-dimensional image detector as set forth in claim 22,

wherein, in said step (c), a thermosetting-type or thermoplastic-type anisotropic conductive adhesive agent is used as said anisotropic conductive adhesive agent, and

said active matrix substrate and said opposing substrate which are disposed so as to face each other are adhered to each other by thermocompression bonding by using a press device.

26. The process for manufacturing the two-dimensional image detector as set forth in claim 25,

wherein said press device is an autoclave device.

27. The process for manufacturing the two-dimensional image detector as set forth in claim 22,

wherein, in said step (c), a photo-curing-type anisotropic conductive adhesive agent is used as said anisotropic conductive adhesive agent, and

light is irradiated from said active matrix substrate side in a state in which said active matrix substrate and said opposing substrate are adhered to each other.

28. The process for manufacturing the two-dimensional image detector as set forth in claim 21,

wherein said step (a) includes the steps of:

(d) forming gate electrode wiring, source electrode wiring, said switching elements, and electrodes of said charge storage capacitors;

(e) forming an insulating protective film for substantially entirely coating said gate electrode wiring, said source electrode wiring, said switching elements, and said electrodes of said charge storage capacitors;

(f) forming a throughhole at a specific location of said insulating protective film; and

(g) forming pixel electrodes on said insulating protective film.

29. The process for manufacturing the two-dimensional image detector as set forth in claim 21,

wherein said step (b) includes the steps of:

(h) forming said semiconductor layer on said electrode layer;

(i) forming on said semiconductor layer a charge blocking layer for blocking intrusion of charges from one surface of said charge blocking layer; and

(j) forming, connection electrodes on said charge blocking layer so as to correspond to said pixel electrodes of said active matrix substrate.

30. The two-dimensional image detector as set forth in claim 29, further comprising the step of forming said electrode layer on a support substrate having permeability with respect to radiation or light before said step (h).

31. The two-dimensional image detector as set forth in claim 29, further comprising the step of forming protrusion electrode s on said connection electrodes so as to correspond to said pixel electrodes of said active matrix substrate after said step (j).

32. A two-dimensional image detector comprising:

an active matrix substrate including switching elements and charge storage capacitors having respective pixel electrodes connected to the switching elements;

an opposing substrate including an electrode layer and a semiconductor layer having photoconductivity, said active matrix substrate and said opposing substrate being disposed so that the charge storage capacitors face the semiconductor layer;

a connection layer, disposed between said substrates, for connecting said substrates to each other; and

wherein said active matrix substrate includes gate electrode wiring and source electrode wiring, and wherein the gate electrode wiring, the source electrode wiring and the switching elements are substantially entirely coated with an insulating protective film.

33. The two-dimensional image detector as set forth in claim 32, wherein said semiconductor layer is made of a crystalline or polycrystalline material, and has excellent sensitivity to X-rays.

34. The two-dimensional image detector as set forth in claim 33, wherein said semiconductor layer is made of a compound semiconductor represented by CdTe or CdZnTe.

35. The two-dimensional image detector as set forth in claim 32, wherein said opposing substrate includes connection electrodes on the semiconductor layer, and each of said connection electrodes is located so as to face a corresponding pixel electrode of said active matrix substrate.

36. The two-dimensional image detector as set forth in claim 35, wherein the pixel electrode has a smaller area than the connection electrode.

37. The two-dimensional image detector as set forth in claim 32, wherein said opposing substrate includes a charge blocking layer on said semiconductor layer, for blocking a flow of charges from one surface of said charge blocking layer.

38. The two-dimensional image detector as set forth in claim 37, wherein said opposing substrate includes connection electrodes on said charge blocking layer, and each of said connection electrodes is located so as to face the pixel electrode of said active matrix substrate.

39. The two-dimensional image detector as set forth in claim 32, wherein said opposing substrate includes a charge blocking layer between the electrode layer and the semiconductor layer.

40. The two-dimensional image detector as set forth in claim 32, wherein said semiconductor layer is also used as a support substrate of said opposing substrate.

41. The two-dimensional image detector as set forth in claim 35, wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

42. The two-dimensional image detector as set forth in claim 38, wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

43. The two-dimensional image detector as set forth in claim 32, wherein protrusion electrodes are provided on said pixel electrodes.

44. The two-dimensional image detector as set forth in claim 32, wherein said semiconductor layer has photoconductivity with respect to radiation.

45. The two-dimensional image detector as set forth in claim 32, wherein said semiconductor layer has photoconductivity with respect to visible light or infrared light, and permeability with respect to visible light or infrared light.

59. The two-dimensional image detector as set forth in claim 32,

wherein said pixel electrodes are disposed on the insulating protective film.

46. A two-dimensional image detector comprising:

an active matrix substrate including switching elements and charge storage capacitor having pixel electrodes connected to the switching elements;

opposing substrate including an electrode layer, a support substrate that is permeable to x-ray or light, and a semiconductor layer having photoconductivity;

wherein said active matrix substrate and said opposing substrate are disposed so that the charge storage copacitors face the semiconductor layer;

a connection layer, disposed between said substrates, for connecting said substrates to each other; and

wherein for said opposing substrate said electrode contacts and is located directly between (i) support substrate having permeability to x-rays or light, and (ii) said semiconductor layer, and wherein said semiconductor layer is on the side of said electrode closest to said active substrate.

47. The two-dimensional image detector as set forth in claim 46, wherein said semiconductor layer is made of a crystalline or polycrystalline material, and has excellent sensitivity to X-rays.

48. The two-dimensional image detector as set forth in claim 47, wherein said semiconductor layer is made of a compound semiconductor represented by CdTe or CdZnTe.

49. The two-dimensional image detector as set forth in claim 46, wherein said opposing substrate includes connection electrodes on the semiconductor layer, and each of said connection electrodes is located so as to face a corresponding pixel electrode of said active matrix substrate.

50. The two-dimensional image detector as set forth in claim 49, wherein the pixel electrode has a smaller area than the connection electrode.

51. The two-dimensional image detector as set forth in claim 46, wherein said opposing substrate includes a charge blocking layer on said semiconductor layer, for blocking a flow of charges from one surface of said charge blocking layer.

52. The two-dimensional image detector as set forth in claim 51, wherein said opposing substrate includes connection electrodes on said charge blocking layer, and each of said connection electrodes is located so as to face the pixel electrode of said active matrix substrate.

53. The two-dimensional image detector as set forth in claim 46, wherein said opposing substrate includes a charge blocking layer between the electrode layer and the semiconductor layer.

54. The two-dimensional image detector as set forth in claim 49, wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

55. The two-dimensional image detector as set forth in claim 52, wherein protrusion electrodes are provided on said connection electrodes so that each of said protrusion electrodes corresponds to said pixel electrode.

56. The two-dimensional image detector as set forth in claim 46, wherein protrusion electrodes are provided on said pixel electrodes.

57. The two-dimensional image detector as set forth in claim 46, wherein said semiconductor layer has photoconductivity with respect to radiation.

58. The two-dimensional image detector as set forth in claim 46, wherein said semiconductor layer has photoconductivity with respect to visible light or infrared light, and permeability with respect to visible light or infrared light.