Miniature camera module

• US 20040189862A1
• Filed: 04/16/2003
• Published: 09/30/2004
• Est. Priority Date: 03/31/2003
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Dialog Semiconductor GmbH (Renesas Electronics Corporation)
• Inventors: Telander, Henrik, Gustavsson, Lars
• Granted Patent: US 7,405,764 B2
• Time in Patent Office: Days
• US Class Current: 348/376
• CPC Class Codes: G02B 13/001 Miniaturised objectives for electronic devices, e.g. portable telephones, webcams, PDAs, small digital cameras G02B23/243 takes precedence
• CPC Class Codes: G02B 13/0015 characterised by the lens design
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 31/0203 Containers; Encapsulations , e.g. encapsulation of photodiodesfor photovoltaic devices H01L31/048; for organic photosensitive devices H10K30/80
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof

Abstract

Digital miniature cameras and methods to manufacture thereof have been achieved. Said miniature cameras having an adjustable focusing device are intended to be used as a built-in modules in hand-held consumer electronic devices, such as e.g. mobile phones and PDAs. The cameras invented have a very small size and produce high-quality pictures. Glue is used to hold different parts together and to seal the joints. The lens is glued in the final stage of the manufacturing line, thus providing the focus setting and the sealing of the cavity that covers the image sensor. A glob top is used to cover and seal the image processor. Said glob top serves two different purposes, first, to distribute the heat away from the sensor and, second, to lock the frame, together with the lens house, into a printed circuit board. In one embodiment a cavity PCB is used to “bury” the sensor of the camera, thus reducing the overall height required. In another embodiment the image processor is mounted on a flexistrip directly underneath the image sensor die, thus reducing the total height of the camera module.

Claims

1. A miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

a lens barrel comprising;

a means to move said barrel;

a means to hold said lens barrel in a focused position;

a housing;

a lens system; and

an IR-cut filter;

a lens holder system holding said lens barrel comprising;

a means to hold said lens barrel in a focused position;

a means to fix said lens barrel in a focused position; and

a housing;

an image sensor chip having photon-receiving elements converting said photons into an image signal;

a flexistrip;

a printed circuit board (PCB) having a cavity wherein said image sensor chip is mounted; and

an image processor.

2. The camera module of claim 1 wherein said electronic devices are hand-held devices.

3. The camera module of claim 2 wherein said hand-held devices are mobile phones.

4. The camera module of claim 2 wherein said hand-held devices are PDAs.

5. The camera module of claim 1 wherein said means to move said lens barrel are dents applied on the surface of said lens barrel and wherein any suitable grip can hold said lens barrel and move it.

6. The camera module of claim 1 wherein said means to hold said lens barrel in a focused position as part of said lens barrel is a thread applied to said lens barrel.

7. The camera module of claim 6 wherein said means to hold said lens barrel in a focused position as part of said lens holder is a thread applied to said lens holder.

8. The camera module of claim 1 wherein said means to hold said lens barrel in a focused position as part of said lens barrel is a projecting jag applied to said lens barrel used to snap-in said lens barrel.

9. The camera module of claim 8 wherein said means to hold said lens barrel in a focused position as part of said lens holder is are dents applied to said lens holder used to snap-in said lens barrel.

10. The camera module of claim 1 wherein said means to fix said lens barrel in a focused position is using glue out of a glue reservoir provided on said lens holder and wherein said glue is flowing from said glue reservoir to said means to hold said lens barrel through a glue groove provided on said lens holder.

11. The camera module of claim 1 wherein a cover glass can be added to said camera module.

12. The camera module of claim 11 wherein said cover glass can be snapped onto said lens holder.

13. The camera module of claim 1 wherein said housing is made out of a metal.

14. The camera module of claim 1 wherein said housing is made out of a polymer containing metal.

15. The camera module of claim 1 wherein said housing is made out of a polymer containing magnetite.

16. The camera module of claim 1 wherein said image sensor chip has been built using CMOS technology.

17. The camera module of claim 1 wherein a glob top is used to seal said image processor.

18. The camera module of claim 17 wherein said glob top is comprising two layers, wherein the first layer, covering directly said image processor is made of electrically isolating material and the second layer, applied on top of the first layer, is electrically conducting.

19. The camera module of claim 17 wherein a plastic frame is shaping and limiting said glob top.

20. The camera module of claim 19 wherein said plastic frame is sloped to the inside on the top surface to hold said glob top.

21. The camera module of claim 1 wherein said image sensor chip is mounted on a flexistrip.

22. The camera module of claim 1 wherein said image processor is mounted on a PCB surrounded by a plastic boarder.

23. A miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

a lens barrel comprising;

a means to move said barrel;

a means to hold said lens barrel in a focused position;

a housing;

a lens system; and

an IR-cut filter;

a lens holder system holding said lens barrel comprising;

a means to fix said lens barrel in a focused position; and

a housing;

an image sensor chip having photon-receiving elements converting said photons into an image signal;

a flexistrip;

a printed circuit board (PCB) having a cavity wherein said image sensor chip is mounted; and

an image processor.

24. The camera module of claim 23 wherein said electronic devices are hand-held devices.

25. The camera module of claim 24 wherein said hand-held devices are mobile phones.

26. The camera module of claim 24 wherein said hand-held devices are PDAs.

27. The camera module of claim 23 wherein said means to move said lens barrel are dents applied on the surface of said lens barrel and wherein any suitable grip can hold said lens barrel and move it.

28. The camera module of claim 23 wherein said means to hold said lens barrel in a focused position is an external lens grip holding said lens barrel using said means to move said lens barrel until the applied glue is cured.

29. The camera module of claim 23 wherein said means to fix said lens barrel in a focused position is using glue out of a glue reservoir provided on said lens holder and wherein said glue is flowing from said glue reservoir to said means to hold said lens barrel through a glue groove provided on said lens holder.

30. The camera module of claim 23 wherein a cover glass can be added to said camera module.

31. The camera module of claim 30 wherein said cover glass can be snapped onto said lens holder.

32. The camera module of claim 23 wherein said housing is made out of a metal.

33. The camera module of claim 23 wherein said housing is made out of a polymer containing metal.

34. The camera module of claim 23 wherein said housing is made out of a polymer containing magnetite.

35. The camera module of claim 23 wherein said image sensor chip has been built using CMOS technology.

36. The camera module of claim 23 wherein a glob top is used to seal said image processor.

37. The camera module of claim 36 wherein said glob top is comprising two layers, wherein the first layer, covering directly said image processor is made of electrically isolating material and the second layer, applied on top of the first layer, is electrically conducting.

38. The camera module of claim 36 wherein a plastic frame is shaping and limiting said glob top.

39. The camera module of claim 38 wherein said plastic frame is sloped to the inside on the top surface to hold said glob top.

40. The camera module of claim 23 wherein said image sensor chip is mounted on a flexistrip.

41. The camera module of claim 23 wherein said image processor is mounted on a PCB surrounded by a plastic boarder.

42. A method to manufacture a miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

providing a flexistrip, a PCB, having a cavity, an image sensor chip, an image processor, a lens barrel comprising a lens system, a means to move said barrel, a means to hold that barrel, and an IR-cut filter, and a lens holder system comprising a means to hold said lens barrel in a focused position, a means to fix said lens barrel in a focused position comprising a glue reservoir and a glue groove, and a housing;

mount PCB on flexistrip;

mount and glue image sensor in cavity of PCB;

mount and glue image processor on PCB;

wire-bond image processor and sensor to PCB;

mount and glue lens holder on PCB;

put glob top on image processor;

mount and focus lens;

test camera module electrically and optically; and

glue lens barrel.

43. The method of claim 42 wherein said gluing of the lens barrel is comprising:

providing a lens barrel, a lens holder comprising a glue reservoir and a groove around said lens barrel to distribute the glue wherein said groove is directly connected to said glue reservoir and an area where said lens barrel can be glued to said lens barrel;

apply the glue into said glue reservoir;

put pressure on the said glue reservoir to guide the glue into said groove;

check the performance of the glue distribution; and

cure the glue.

44. The method of claim 43 wherein said glue has a low viscosity.

45. The method of claim 43 wherein said check of the performance is using a vision system.

46. The method of claim 43 wherein said check of the performance is limited to the potential detection of glue rests in said glue reservoir.

47. The method of claim 43 wherein said glue is colored.

48. The method of claim 43 wherein said glue is cured using UV-light.

49. A miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

a lens barrel comprising;

a means to move said barrel;

a means to hold said lens barrel in a focused position;

a housing;

a lens system; and

an IR-cut filter;

a lens holder system holding said lens barrel comprising;

a means to hold said lens barrel in a focused position;

a means to fix said lens barrel in a focused position; and

a housing;

an image sensor chip having photon-receiving elements converting said photons into an image signal;

an image processor;

a flexistrip on which said image processor is mounted; and

a printed circuit board (PCB) on which said image sensor chip is mounted.

50. The camera module of claim 49 wherein said electronic devices are hand-held devices.

51. The camera module of claim 50 wherein said hand-held devices are mobile phones.

52. The camera module of claim 50 wherein said hand-held devices are PDAs.

53. The camera module of claim 49 wherein said means to move said lens barrel are dents applied on the surface of said lens barrel and wherein any suitable grip can hold said lens barrel and move it.

54. The camera module of claim 49 wherein said means to hold said lens barrel in a focused position as part of said lens barrel is a thread applied to said lens barrel.

55. The camera module of claim 54 wherein said means to hold said lens barrel in a focused position as part of said lens holder is a thread applied to said lens holder.

56. The camera module of claim 49 wherein said means to hold said lens barrel in a focused position as part of said lens barrel is a projecting jag applied to said lens barrel used to snap-in said lens barrel.

57. The camera module of claim 56 wherein said means to hold said lens barrel in a focused position as part of said lens holder is are dents applied to said lens holder used to snap-in said lens barrel.

58. The camera module of claim 57 wherein said means to fix said lens barrel in a focused position is using glue out of a glue reservoir provided on said lens holder and wherein said glue is flowing from said glue reservoir to said means to hold said lens barrel through a glue groove provided on said lens holder.

59. The camera module of claim 49 wherein a cover glass can be added to said camera module.

60. The camera module of claim 59 wherein said cover glass can be snapped onto said lens holder.

61. The camera module of claim 49 wherein said housing is made out of a metal.

62. The camera module of claim 49 wherein said housing is made out of a polymer containing metal.

63. The camera module of claim 49 wherein said housing is made out of a polymer containing magnetite.

64. The camera module of claim 49 wherein said image sensor chip has been built using CMOS technology.

65. The camera module of claim 49 wherein a glob top is used to seal said image processor.

66. The camera module of claim 49 wherein said glob top is comprising two layers, wherein the first layer, covering directly said image processor is made of electrically isolating material and the second layer, applied on top of the first layer, is electrically conducting.

67. The camera module of claim 65 wherein a plastic frame is shaping and limiting said glob top.

68. The camera module of claim 49 wherein said image sensor chip is mounted on a PCB.

69. The camera module of claim 49 wherein said image processor is mounted on a flexistrip surrounded by a plastic boarder.

70. A method to manufacture a miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

providing a flexistrip, a PCB, an image sensor chip being mounted on said PCB, an image processor being mounted on a flexistrip underneath said image sensor, a lens barrel comprising a lens system, a means to move said barrel, a means to hold that barrel in a focused position, a means to fix said lens barrel in a focused position comprising a glue reservoir and a glue groove, and a IR-cut filter, and a lens holder system comprising an adjustable focusing device, a glue reservoir, and a housing;

mount PCB on flexistrip;

mount and glue image processor die on flexistrip;

wire-bond image processor to flexistrip;

mount and glue plastic boarder on flexistrip;

fill plastic boarder with glob top;

flip PCB and mount and glue image sensor on PCB;

wire-bond image sensor to PCB;

mount and glue lens holder on PCB;

mount lens barrel and focus lens;

glue lens barrel; and

test camera module electrically and optically.

71. The method of claim 70 wherein said gluing of the lens barrel is comprising:

providing a lens barrel, a lens holder comprising a glue reservoir and a groove around said lens barrel to distribute the glue wherein said groove is directly connected to said glue reservoir and an area where said lens barrel can be glued to said lens barrel;

apply the glue into said glue reservoir;

put pressure on the said glue reservoir to guide the glue into said groove;

check the performance of the glue distribution; and

cure the glue.

72. The method of claim 71 wherein said glue has a low viscosity.

73. The method of claim 71 wherein said check of the performance is using a vision system.

74. The method of claim 71 wherein said check of the performance is limited to the potential detection of glue rests in said glue reservoir.

75. The method of claim 71 wherein said glue is colored.

76. The method of claim 71wherein said glue is cured using UV-light.

78. The method of claim 70 wherein said gluing of the lens barrel is comprising:

providing a lens barrel, a lens holder comprising a glue reservoir and a groove around said lens barrel to distribute the glue wherein said groove is directly connected to said glue reservoir and an area where said lens barrel can be glued to said lens barrel;

apply the glue into said glue reservoir;

put pressure on the said glue reservoir to guide the glue into said groove;

check the performance of the glue distribution; and

cure the glue.

79. The method of claim 78 wherein said glue has a low viscosity.

80. The method of claim 78 wherein said check of the performance is using a vision system.

81. The method of claim 78 wherein said check of the performance is limited to the potential detection of glue rests in said glue reservoir.

82. The method of claim 78 wherein said glue is colored.

83. The method of claim 78 wherein said glue is cured using UV-light.

77. A method to manufacture a miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

providing a flexistrip having integrated plastic boarders, a PCB, an image sensor chip being mounted on said PCB, an image processor being mounted on a flexistrip underneath said image sensor, a lens barrel comprising a lens system, a means to move said barrel, a means to hold that barrel in a focused position, a means to fix said lens barrel in a focused position comprising a glue reservoir and a glue groove, and a IR-cut filter, and a lens holder system comprising an adjustable focusing device, a glue reservoir, and a housing;

mount PCB on flexistrip having integrated plastic boarder;

mount and glue image processor die on flexistrip within said plastic boarder;

wire-bond image processor to flexistrip;

fill plastic boarder with glob top;

flip PCB and mount and glue image sensor on PCB;

wire-bond image sensor to PCB;

mount and glue lens holder on PCB;

mount lens barrel and focus lens;

glue lens barrel; and

test camera module electrically and optically.

84. A method to manufacture a miniature camera module having a very small size to be used as a built-in module in electronic devices comprising:

providing a flexistrip, a PCB, an image sensor chip being mounted on said PCB, an image processor being mounted on a flexistrip underneath said image sensor, a lens barrel comprising a lens system, a means to move said barrel, a means to hold that barrel in a focused position, a means to fix said lens barrel in a focused position comprising a glue reservoir and a glue groove, and a IR-cut filter, and a lens holder system comprising an adjustable focusing device, a glue reservoir, and a housing;

glue image processor die on a PCB;

wire-bond image processor to said PCB;

mould image processor die inside a plastic boarder using glob top;

flip PCB and mount and glue image sensor on PCB;

wire-bond image sensor to PCB;

mount and glue lens holder on PCB;

mount and glue lens into lens barrel;

mount lens barrel and focus lens;

perform electrical and optical tests;

glue lens barrel to lens holder;

mount flexistrip on bottom side of PCB; and

test camera module electrically and optically additionally.

85. The method of claim 84 wherein said gluing of the lens barrel is comprising:

providing a lens barrel, a lens holder comprising a glue reservoir and a groove around said lens barrel to distribute the glue wherein said groove is directly connected to said glue reservoir and an area where said lens barrel can be glued to said lens barrel;

apply the glue into said glue reservoir;

put pressure on the said glue reservoir to guide the glue into said groove;

check the performance of the glue distribution; and

cure the glue.

86. The method of claim 85 wherein said glue has a low viscosity.

87. The method of claim 85 wherein said check of the performance is using a vision system.

88. The method of claim 85 wherein said check of the performance is limited to the potential detection of glue rests in said glue reservoir.

89. The method of claim 85 wherein said glue is colored.

90. The method of claim 85 wherein said glue is cured using UV-light.