CONCAVE SPACER-WAFER APERTURES AND WAFER-LEVEL OPTICAL ELEMENTS FORMED THEREIN

• US 20150362705A1
• Filed: 06/17/2014
• Published: 12/17/2015
• Est. Priority Date: 06/17/2014
• Status: Active Grant

• Current Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Original Assignee: Omnivision Technologies Incorporated (Will Semiconductor Co., Ltd. Shanghai)
• Inventors: NABIGHIAN, Edward, MARTIN, Alan
• Granted Patent: US 9,798,114 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29C 33/0055 with incorporated overflow cavities in particular in injection moulds B29C45/2669
• CPC Class Codes: B29L 2011/0016 Lenses
• CPC Class Codes: G02B 13/0085 employing wafer level optics
• CPC Class Codes: G02B 7/022 lens and mount having complementary engagement means, e.g. screw/thread

Abstract

Wafer-level optical elements and the concave spacer-wafer apertures in which they are formed are disclosed. The wafer-level optical elements include a spacer wafer comprising a plurality of apertures. Each aperture has a concave shape in a planar cross-section of the spacer wafer and an overflow region intersecting the planar cross-section. The wafer-level optical elements also include an array of optical elements, each optical element of the array being formed of cured flowable material within a respective one of the plurality of apertures. A portion of the cured flowable material forming each optical element extends into the overflow region of the respective aperture of the plurality of apertures. The spacer wafer includes a plurality of apertures, each of the plurality of apertures having a concave shape in a planar cross-section of the spacer wafer. Each of the plurality of apertures includes an overflow region intersecting the planar cross-section.

Claims

1. Wafer-level optical elements, comprising:

a spacer wafer formed with a plurality of apertures, each of the plurality of apertures having concave shape in a planar cross-section of the spacer wafer and including an overflow region intersecting the planar cross-section; and

a plurality of optical elements, each of the optical elements being formed of a cured flowable material within a respective one of the plurality of apertures;

wherein a portion of the cured flowable material that forms each of the optical elements extends into its respective aperture'"'"'s overflow region.

2. The wafer-level optical elements of claim 1, wherein the concave shape is a polygon.

3. The wafer-level optical elements of claim 1, wherein the concave shape is a union of a plurality of geometric shapes.

4. The wafer-level optical elements of claim 3, wherein one of the plurality of geometric shapes is a convex polygon or a circle.

5. The wafer-level optical elements of claim 1, wherein the concave shape is formed with one or both of reflection symmetry and rotational symmetry.

6. The wafer-level optical elements of claim 1, wherein each optical element of the array of optical elements is formed with a membrane that surrounds and suspends its respective optical element within its respective aperture.

7. The wafer-level optical elements of claim 6, wherein for each of the plurality of apertures, a line tangential to a sidewall profile of the aperture forms an oblique angle with a planar surface of the spacer wafer.

8. The wafer-level optical elements of claim 6, wherein a line normal to a plane defined by one of two parallel spacer wafer surfaces intersects both a membrane and the spacer wafer.

9. A spacer wafer comprising:

at least one concave aperture formed with a concave shape in a planar cross-section of the spacer wafer and including an overflow region intersecting the planar cross-section.

10. The spacer wafer of claim 9, wherein the concave shape is a polygon.

11. The spacer wafer of claim 9, wherein the concave shape is a union of a plurality of geometric shapes.

12. The spacer wafer of claim 11, wherein one of the plurality of geometric shapes is selected from the group consisting of a convex polygon, a circle, and an ellipse.

13. The spacer wafer of claim 9, wherein the concave shape is formed with one or both of reflection symmetry and rotational symmetry.

14. The spacer wafer of claim 9, wherein a line tangential to a point on the concave aperture'"'"'s profiled sidewall makes an oblique angle with respect to a planar surface of the spacer wafer.

15. The spacer wafer of claim 9, wherein one of two parallel spacer wafer surfaces defines a plane and a line normal to the plane intersects the spacer wafer over a distance that is shorter than a thickness of the spacer wafer.

16. The spacer wafer of claim 9, wherein the concave aperture is at least in part defined by a spacer-wafer aperture sidewall that is formed as a profiled aperture sidewall.

17. The spacer wafer of claim 16, wherein the profiled aperture sidewall is formed with a shaped profile at least at a portion of the profiled aperture sidewall configured to support a membrane that suspends an optical element.

18. The spacer wafer of claim 16, wherein the profiled aperture sidewall is formed with a concave profile.

19. The spacer wafer of claim 16, wherein the profiled aperture sidewall is formed with a convex profile.

20. The spacer wafer of claim 16, wherein the profiled aperture sidewall is formed with a combination of a concave profile and a convex profile.