METHOD FOR MANUFACTURING LENSES, IN PARTICULAR FOR AN IMAGER COMPRISING A DIAPHRAGM

• US 20080006859A1
• Filed: 06/18/2007
• Published: 01/10/2008
• Est. Priority Date: 06/19/2006
• Status: Active Grant

• Current Assignee: Stmicroelectronics Rousset SAS (STMicroelectronics NV)
• Original Assignee: Stmicroelectronics Rousset SAS (STMicroelectronics NV)
• Inventors: Mionetto, Roberto
• Granted Patent: US 7,580,204 B2
• Time in Patent Office: Days
• US Class Current: 257/294
• CPC Class Codes: B29C 2791/009 Using laser
• CPC Class Codes: B29C 71/04 by wave energy or particle radiation , e.g. for curing or vulcanising preformed articles during moulding, e.g. in a mould B29C35/08
• CPC Class Codes: B29D 11/00009 Production of simple or compound lenses
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: B41M 5/265 for the production of optical filters or electrical components
• CPC Class Codes: G02B 3/0018 Reflow, i.e. characterized by the step of melting microstructures to form curved surfaces, e.g. manufacturing of moulds and surfaces for transfer etching
• CPC Class Codes: G02B 3/0025 Machining, e.g. grinding, polishing, diamond turning, manufacturing of mould parts
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence

Abstract

A method for manufacturing a lens of a polymer material, comprises producing in the core of the lens or on the surface of the latter at least one opaque zone having an optical function, by locally degrading the molecular structure of the polymer material using a beam of laser light. Example application is provided in particular but not exclusively to CMOS imagers.

Claims

1. A method for manufacturing a lens of a polymer material, the method comprising producing in or on the lens at least one opaque zone having an optical function, by locally degrading a molecular structure of the polymer material using a beam of laser light.

2. The method according to claim 1 wherein the laser beam is applied to the lens using a variable focus device comprising a wide-angle lens, enabling a distance between the zone to be degraded and a surface of the lens to be chosen.

3. The method according to claim 1 wherein the opaque zone forms a diaphragm.

4. The method according to claim 1, further comprising producing a plurality of contiguous opaque zones forming a diffraction grating having an optical filter function.

5. The method according to claim 1 wherein the opaque zone is produced during manufacturing the lens in which the lens has a flat face, by applying the laser beam to the flat face.

6. The method according to claim 5 wherein the production of the opaque zone is followed by rounding the flat face of the lens.

7. The method according to claim 1, comprising manufacturing at least two lenses, producing at least one opaque zone in at least one of the two lenses, and assembling the two lenses to form a complex lens.

8. A method for manufacturing an integrated micro-module for capturing images, the method comprising:

manufacturing at least one imager on a semiconductor substrate;

manufacturing at least one lens;

producing in or on the lens at least one opaque zone in accordance with the method according to claim 1;

and

assembling the lens directly onto the semiconductor substrate, without using any lens-holder frame.

9. A method for collectively manufacturing integrated optical micro-modules, the method comprising:

collectively manufacturing a plurality of imagers on a semiconductor wafer;

collectively manufacturing a plurality of lenses on at least one plate having one or more layers of polymer material and forming a lens wafer;

producing at least one opaque zone in or on lenses out of the plurality of lenses, in accordance with the method according to claim 1;

assembling the lens wafer and the semiconductor wafer, so that each lens is opposite an imager; and

cutting out the assembly to obtain a plurality of integrated optical micro-modules.

10. A lens of a polymer material, the lens comprising at least one opaque zone having an optical function, the opaque zone being a zone in which the polymer material has a degraded molecular structure.

11. The lens according to claim 10 wherein said opaque zone has a diaphragm function.

12. The lens according to claim 10, further comprising a plurality of contiguous opaque zones forming a diffraction grating having an optical filter function.

13. The lens according to claim 10, further comprising two flat faces.

14. The lens according to claim 10, further comprising a flat face and a convex or concave face.

15. The lens according to claim 10, further comprising two convex faces.

16. The lens according to claim 10, comprising two layers of polymer material assembled against one another, at least one of the layers having said at least one opaque zone having said optical function.

17. The lens according to claim 16 wherein each layer has a convex face and the convex faces of each layer are arranged face to face to form a lenticular cavity.

18. A micro-module for capturing images, the micro-module comprising an imager on a semiconductor substrate, and at least one lens according to claim 10.

19. The micro-module according to claim 18 wherein the lens is stuck onto the imager without any lens-holder frame.

20. An apparatus, comprising:

an imaging device having a micro-module to capture images, the micro-module including;

an imager on a semiconductor substrate; and

at least one lens made of a polymer material, said at least one lens having at least one opaque zone in which said polymer material has a degraded molecular structure and having a region different from said at least one opaque zone in which said polymer material maintains said molecular structure to allow light to pass through said region, said at least one opaque zone having an optical function.

21. The apparatus of claim 20 wherein said imaging device is a web camera, video camera, cellular telephone, or digital camera.

22. The apparatus of claim 20 wherein said imager is a complementary metal oxide semiconductor (CMOS) imager.

23. The apparatus of claim 20 wherein said at least one opaque zone is located within said lens at a distance from a surface of said at least one lens.

24. The apparatus of claim 20 wherein said at least one opaque zone is located on a surface of said lens.

25. The apparatus of claim 20 wherein said optical function is a diaphragm function.

26. The apparatus of claim 20 wherein said at least one opaque zone includes a plurality of contiguous ones said at least one opaque zone, said plurality forming a diffraction grating that provides said optical function as an optical filter function.