TIR imaging lens, image capturing system having the same, and associated methods

Patent metadata

Field	Value
Publication number	US-10409041-B2
Application number	US-201815933014-A
Country	US
Kind code	B2
Filing date	Mar 22, 2018
Priority date	Jan 23, 2012
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A method of manufacturing lenses includes creating a wafer-level master, overmolding the wafer-level master to form a daughter replica, casting a polymer lens shapes onto a wafer using the daughter replica, transferring the polymer lens shapes into the wafer, and singulating the wafer to create individual dies with a lens thereon. The wafer may be silicon, e.g., silicon having a resistivity between 0.1 and 100 Ωcm.

First claim

What is claimed is:

1. A method of manufacturing lenses, the method comprising:
creating a wafer-level master;
overmolding the wafer-level master to form a daughter replica;
casting a polymer lens shapes onto a silicon wafer having a resistivity between 0.1 and 100 Ωm using the daughter replica;
transferring the polymer lens shapes into the wafer; and
singulating the wafer to create individual dies with a lens thereon.

2. The method as claimed in claim 1 , wherein creating the wafer-level master includes machining a metal substrate.

3. The method as claimed in claim 2 , wherein machining includes diamond turning.

4. The method as claimed in claim 2 , wherein creating the wafer-level master includes machining perturbed lens shapes into the wafer-level master such that the transferred lens shape in silicon best meets a desired lens shape.

5. The method as claimed in claim 1 , further comprising, before singulating, forming die features on the wafer, at least one die feature being on the individual die.

6. The method as claimed in claim 5 , wherein the die features include at least one of a die alignment mark, a wafer alignment mark, and a die identifier.

7. The method as claimed in claim 5 , further comprising, before casting the polymer lens shapes, patterning die features in photoresist on a surface of the wafer to have polymer lens shapes cast thereon.

8. The method as claimed in claim 7 , further comprising transferring the die features into the wafer.

9. The method as claimed in claim 8 , wherein transferring the die features occurs during transferring the polymer lens shapes.

10. The method as claimed in claim 5 , further comprising, after casting the polymer lens shapes and before transferring, patterning die features on a surface of the wafer having the polymer lens shapes thereon.

11. The method as claimed in claim 10 , wherein patterning includes:
depositing a hard mask on the surface of the wafer; and
patterning the hard mask.

12. The method as claimed in claim 11 , wherein patterning includes providing a photoresist pattern on the hard mask and etching the hard mask.

13. The method as claimed in claim 12 , further comprising removing polymer while not affecting the hard mask until the wafer is exposed.

14. The method as claimed in claim 13 , further comprising removing the hard mask and the photoresist.

15. The method as claimed in claim 1 , wherein singulating includes etching.

16. The method as claimed in claim 1 , further comprising, after transferring but before singulating, providing a coating on the wafer.

17. The method as claimed in claim 16 , wherein the coating is one of an antireflective coating and a short wave cut filter.

18. The method as claimed in claim 16 , wherein coating includes coating both surfaces of the wafer.

19. The method as claimed in claim 16 , further comprising, after providing the coating and before singulating, forming aperture stops on the lenses.

20. The method as claimed in claim 19 , wherein forming aperture stops includes patterning chrome.

21. The method as claimed in claim 1 , further comprising, before casting, measuring a resistivity of the wafer.

22. The method as claimed in claim 1 , continuing the method when the wafer has a resistivity between 1 and 10 Ωm.

23. The method as claimed in claim 1 , further comprising, before singulating, forming aperture stops on the lenses.

24. The method as claimed in claim 1 , wherein singulating creates circular dies.

25. The method as claimed in claim 1 , wherein singulating creates non-circular dies.

Assignees

• Flir Systems

Inventors

• Ovrutsky David
• Huddleston Jeremy
• Elliott Paul
• Keller David
• Jones Richard
• Mercier Thomas

Classifications

• H04N23/57

  Mechanical or electrical details of cameras or camera modules specially adapted for being embedded in other devices · CPC title

• G02B13/14 Primary

  for use with infrared or ultraviolet radiation ({G02B13/008, } G02B13/16 take precedence) · CPC title

• G02B13/22

  Telecentric objectives or lens systems · CPC title

• H04N5/2257

  Electricity · mapped topic

• H04N5/33

  Transforming infrared radiation (cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20) · CPC title