Polymer patterned disk stack manufacturing

Patent metadata

Field	Value
Publication number	US-12038591-B2
Application number	US-202016909760-A
Country	US
Kind code	B2
Filing date	Jun 23, 2020
Priority date	Jun 24, 2019
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A method of aligning a stencil to an eyepiece wafer includes providing the stencil, positioning the stencil with respect to a first light source, and determining locations of at least two stencil apertures. The method also includes providing the eyepiece wafer. The eyepiece wafer includes at least two eyepiece waveguides, each eyepiece waveguide including an incoupling grating and a corresponding diffraction pattern. The method further includes directing light from one or more second light sources to impinge on each of the corresponding diffraction patterns, imaging light diffracted from each incoupling grating, determining at least two incoupling grating locations, determining offsets between corresponding stencil aperture locations and incoupling grating locations, and aligning the stencil to the eyepiece wafer based on the determined offsets.

First claim

What is claimed is:

1. A method of aligning a stencil to an eyepiece wafer, the method comprising:
providing the stencil;
positioning the stencil with respect to a first light source;
determining locations of at least two stencil apertures;
providing the eyepiece wafer, wherein the eyepiece wafer includes at least two eyepiece waveguides, each eyepiece waveguide including an incoupling grating and a corresponding diffraction pattern;
directing light from one or more second light sources to impinge on each of the corresponding diffraction patterns and propagate through each corresponding eyepiece waveguide by total internal reflection;
imaging light diffracted from each incoupling grating;
determining at least two incoupling grating locations;
determining offsets between corresponding stencil aperture locations and incoupling grating locations; and
aligning the stencil to the eyepiece wafer based on the determined offsets.

2. The method of claim 1 wherein the at least two stencil aperture locations comprise four aperture locations or six aperture locations.

3. The method of claim 1 wherein determining the at least two stencil aperture locations comprises:
imaging light from the first light source using a first camera after the light from the first light source passes through a first aperture of the at least two stencil apertures; and
imaging light from the first light source using a second camera after the light from the first light source passes through a second aperture of the at least two stencil apertures.

4. The method of claim 1 wherein determining the at least two stencil aperture locations comprises:
imaging light from the first light source using a camera after the light from the first light source passes through a first aperture of the at least two stencil apertures; and
imaging light from the first light source using the camera after the light from the first light source passes through a second aperture of the at least two stencil apertures.

5. The method of claim 1 further comprising, after directing light from each of the one or more second light sources to impinge on each of the corresponding diffraction patterns, redirecting at least a portion of the light from each of the one or more second light sources to each of the incoupling gratings via total internal reflection.

6. The method of claim 1 wherein imaging light diffracted from each incoupling grating comprises:
imaging light from a primary light source of the one or more second light sources using a first camera after the light from primary light source diffracts from a first incoupling grating of the incoupling gratings; and
imaging light from a secondary light source of the one or more second light sources using a second camera after the light from the secondary light source through a second incoupling grating of the incoupling gratings.

7. The method of claim 1 wherein imaging light diffracted from each incoupling grating comprises:
imaging light from a primary light source of the one or more second light sources using a camera after the light from the primary light source diffracts from a first incoupling grating of the incoupling gratings; and
imaging light from a secondary light source of the one or more second light sources using the camera after the light from the secondary light source diffracts from a second incoupling grating of the incoupling gratings.

8. The method of claim 1 wherein aligning the stencil to the eyepiece wafer comprises moving the eyepiece wafer with respect to the stencil to reduce the determined offsets.

9. The method of claim 8 wherein moving the eyepiece wafer comprises translating and rotating the eyepiece wafer and reducing the determined offsets comprises minimizing the determined offsets.

10. The method of claim 1 wherein the at least two eyepiece waveguides are disposed in a lateral plane and correspond to a first eyepiece waveguide having a first diffraction pattern and a first incoupling grating and a second eyepiece waveguide having a second diffraction pattern and a second incoupling grating.

11. The method of claim 10 wherein the first incoupling grating is disposed in the lateral plane at a first lateral position and the first diffraction pattern is disposed in the lateral plane at a second lateral position laterally offset from the first lateral position, and wherein the second incoupling grating is disposed in the lateral plane at a third lateral position and the second diffraction pattern is disposed in the lateral plane at a fourth lateral position laterally offset from the third lateral position.

Assignees

• Magic Leap Inc

Inventors

• Li Ling
• Chang Chieh
• Bhagat Sharad D
• Peroz Christophe
• Hill Brian George
• Patterson Roy Matthew
• Sadam Satish

Classifications

• H10W46/607

  Located on parts of packages, e.g. on encapsulations or on package substrates · CPC title

• H10W46/401

  for identification or tracking · CPC title

• H10W46/301

  for alignment · CPC title

• H10W46/00 Primary

  Marks applied to devices, e.g. for alignment or identification · CPC title

• H10P74/27

  Structural arrangements therefor · CPC title