Lens array block for image capturing unit and methods of fabrication

• US 8,013,289 B2
• Filed: 10/26/2007
• Issued: 09/06/2011
• Est. Priority Date: 11/15/2006
• Status: Expired due to Fees

• Current Assignee: Ether Precision, Inc.
• Original Assignee: Ether Precision, Inc.
• Inventors: Chang, Chao-Chi, Chen, Yung-I, Lusinchi, Jean-Pierre, Hsiao, Raymond Chih-Chung
• Primary Examiner(s): Le, Que T
• Assistant Examiner(s): BUI PHO, PASCAL M
• Application Number:
  US11/925,742
• Publication Number:
  US 20080121784A1
• Time in Patent Office: 1,411 Days
• Field of Search: 250/216, 250/208.1, 250/239, 358/484, 358/494, 358/496, 257/433, 257/434, 257/678, 257/680, 257/685, 257/686, 257/723, 438 64- 66, 438/106, 438/116
• US Class Current: 250/239
• CPC Class Codes: H01L 27/1462 Coatings
• CPC Class Codes: H01L 31/02325 the optical elements not being integrated nor being directly associated with the device
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• 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
• CPC Class Codes: H04N 23/57 Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1089 of discrete laminae to single face of additional lamina
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A lens array block comprises a plurality of lens barrels joined to one another form a three-dimensional unitary structure. Each lens barrel comprises a stepped cylindrical chamber having a through hole with an internal profile having first and second steps that are spaced apart through the height of the through hole, the second step being radially inward of the first step. An image capturing unit comprising the lens block array, and methods of fabrication and assembly are also described.

Claims

1. A lens array block comprising a three-dimensional unitary structure comprising a plurality of lens barrels joined to one another and spaced apart in a periodic arrangement to form a three-dimensional unitary structure, the unitary structure comprising:

(a) a first plate having a plurality of first through holes having first diameters; and

(b) a second plate joined to the first plate by an adhesive, the second plate having a plurality of second through holes that are aligned with the first through holes in the first plate, the second through holes having second diameters which are smaller than the first diameters to form a stepped cylindrical chamber for positioning at least one lens therein, and

wherein each lens barrel can be cut from the unitary structure to form a separate image capturing unit.

2. A lens array block according to claim 1 comprising a periodic arrangement of cubes joined together at side surfaces, wherein each cube comprises a lens barrel.

3. A lens array block according to claim 2 wherein the cubes are made from a dielectric, semiconductor or conductor material.

4. A lens array block according to claim 3 wherein the cubes comprise glass, ceramic, metal, or polymer.

5. A lens array block according to claim 1 wherein each stepped cylindrical chamber comprises a plurality of concentric cylinders having a common central axis and being stacked upon one another.

6. A lens array block according to claim 1 wherein each lens barrel comprises a plurality of different diameters.

7. A lens array block according to claim 1 wherein the first plate is thicker than the second plate.

8. A lens array block according to claim 1 wherein

the first plate comprises a plurality of first sidewalls that each extend around a first through hole, each first sidewall abutting a top surface with a circumferential protrusion;

and

the second plate comprises a plurality of second sidewalls that each extend around a second through hole, each second sidewall abutting a bottom surface with a circumferential slot which is shaped and sized to receive the circumferential protrusion of the first plate.

9. A lens array block according to claim 1 further comprising one or more lenses in each lens barrel.

10. A lens array block according to claim 1 further comprising a lens in each lens barrel, the lens having a diameter of less than about 1.5 mm.

11. A lens array block according to claim 1 further comprising a backing plate which serves as a support during separation of the lens barrels from the lens array block.

12. A lens array block according to claim 1 further comprising an image sensor array having a plurality of image sensors which are also spaced apart from one another in a periodic arrangement which is selected to match the arrangement of the lens barrels.

13. A lens array block according to claim 1 further comprising a lens assembled into each lens barrel while the lens barrels are still joined together.

14. A lens array block according to claim 1 wherein the first and second plates are made of glass, silicon oxide, aluminum oxide, quartz, aluminum nitride or silicon.

15. A lens array block according to claim 1 wherein the first through holes in the first plate and the second through holes in the second plate are sized with a diameter of from about 0.5 to about 3 mm for positioning at least one lens into each lens barrel.

16. An image capture module array comprising:

(a) a lens array block comprising a plurality of lens barrels joined to one another and spaced apart in a periodic arrangement in a three-dimensional unitary structure comprising;

(i) a first plate having a plurality of first through holes having first diameters, and a top surface with a plurality of circumferential protrusions; and

(ii) a second plate joined to the first plate by an adhesive, the second plate having a plurality of second through holes that are aligned with the first through holes in the first plate to a common and aligned central axis by aligning a plurality of circumferential slots on a bottom surface of the second plate with the circumferential protrusions on the top surface of the first plate, and the second through holes having second diameters which are smaller than the first diameters by at least about 10% to form a stepped cylindrical chamber for positioning at least one lens therein, and

wherein each lens barrel can be cut from the unitary structure to form a separate image capturing unit; and

(b) a plate having an array of image sensors which are aligned and joined to the lens array block such that each image sensor is directly below a through hole of a lens barrel.

17. An image capture module array according to claim 16 wherein the first and second plates are made of glass, silicon oxide, aluminum oxide, quartz, aluminum nitride or silicon.

18. An image capture module array according to claim 16 wherein the first through holes in the first plate and the second through holes in the second plate are sized with a diameter of from about 0.5 to about 3 mm for positioning at least one lens into each lens barrel.

19. A method of forming a lens array block, the method comprising:

(a) providing first and second plates;

(b) forming a plurality of first through holes through the first plate, the first through holes each having a first diameter;

(c) forming a plurality of second through holes through the second plate, the second through holes each having second diameter that is a different diameter than the first diameter;

(d) aligning the first through holes to the second through holes to form stepped cylindrical chambers, each stepped cylindrical comprising a first through hole and a second through hole that each have a common central axis; and

(e) joining the first and second plates to one another with an adhesive to form a lens array block having a plurality of lens barrels that are spaced apart from one another in a periodic arrangement such that the lens barrels can be cut to form separate image capturing units.

20. A method according to claim 19 comprising forming the first and second plates from a dielectric, semiconductor or conductor material.

21. A method according to claim 19 comprising forming the first and second plates from glass, ceramic, metal, or polymer.

22. A method according to claim 19 comprising forming the first and second through holes such that the second diameter is smaller than the first diameter by at least 10%.

23. A method according to claim 19 wherein the first plate comprises a thickness of less than 1600 microns, and the second plate is thinner than the first plate and comprises a thickness of less than 600 microns.

24. A method according to claim 19 comprising forming the first and second through holes by a wet or dry etching process.

25. A method according to claim 19 comprising forming the first and second through holes by laser drilling.

26. A method according to claim 19 further comprising:

(f) providing a third plate;

(g) forming a plurality of third through holes through the third plate, the third through holes having a third diameters that are larger than the first diameters of the first holes;

(h) aligning the third through holes to the central axis of the aligned first and second through holes; and

(i) joining the third plate to the first and second plates with an adhesive.

27. A method according to claim 19 further comprising placing one or more lenses in each lens barrel.

28. A method according to claim 19 further comprising placing a lens in each lens barrel, the lens having a diameter of less than about 1.5 mm.

29. A method according to claim 19 further comprising adhering a backing plate to the lens array block to serve as a support during separation of the lens barrels from the lens array block.

30. A method according to claim 29 further comprising placing the backing plate onto an image sensor array having a plurality of image sensors which are also spaced apart from one another in a periodic arrangement which is selected to match the arrangement of the lens barrels.

31. A method according to claim 19 further comprising placing the lens array block onto an image sensor array having a plurality of image sensors which are also spaced apart from one another in a periodic arrangement which is selected to match the arrangement of the lens barrels.

32. A method according to claim 31 comprising separating the lens barrels from one another after assembling the lens array block onto the image sensor array to form individual image capturing units.

33. A method according to claim 19 further comprising assembling a lens into each lens barrel while the lens barrels are still joined together.

34. A method according to claim 19 comprising separating the lens barrels before or after a lens is assembled into each lens barrel.

35. A method according to claim 19 comprising forming the first and second plates from glass, silicon oxide, aluminum oxide, quartz, aluminum nitride or silicon

36. A method according to claim 19 wherein steps (b) and (c) each comprise forming first and second through holes that are each sized with a diameter of from about 0.5 to about 3 mm for positioning at least one lens into each lens barrel.