Injection molded microoptics

Patent metadata

Field	Value
Publication number	US-10490594-B2
Application number	US-201615294283-A
Country	US
Kind code	B2
Filing date	Oct 14, 2016
Priority date	Aug 2, 2005
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

A wafer-scale apparatus and method is described for the automation of forming, aligning and attaching two-dimensional arrays of microoptic elements on semiconductor and other image display devices, backplanes, optoelectronic boards, and integrated optical systems. In an ordered fabrication sequence, a mold plate comprised of optically designed cavities is formed by reactive ion etching or alternative processes, optionally coated with a release material layer and filled with optically specified materials by an automated fluid-injection and defect-inspection subsystem. Optical alignment fiducials guide the disclosed transfer and attachment processes to achieve specified tolerances between the microoptic elements and corresponding optoelectronic devices and circuits. The present invention applies to spectral filters, waveguides, fiber-optic mode-transformers, diffraction gratings, refractive lenses, diffractive lens/Fresnel zone plates, reflectors, and to combinations of elements and devices, including microelectromechanical systems (MEMS) and liquid crystal device (LCD) matrices for adaptive, tunable elements. Preparation of interfacial layer properties and attachment process embodiments are taught.

First claim

What is claimed is:

1. A method of using an injection molding process for both optical coupling elements and solder electrical interconnects, the method comprising:
injection molding an array of microlenses in a first mold;
transferring the array of microlenses onto a semiconductor wafer, each of the microlenses comprising optical polymers or glasses including a color absorbing filter integrated into the optical polymers or glasses of the each molded microlens to form a spectrally absorptive microlens,
aligning a second mold to said wafer, said second mold including a set of solder openings for conducting molten solder through the second mold;
placing said second mold in close contact with the wafer;
injecting molten solder through the set of solder openings and onto the semiconductor wafer to form electrical interconnects on the wafer;
removing the second mold from the wafer, leaving said electrical interconnects on the wafer for making connections with circuit elements.

2. The method according to claim 1 , wherein the second mold includes a set of microlens openings to facilitate placing the second mold in close contact with the wafer without contacting the microlenses.

3. The method according to claim 2 , wherein the placing said second mold in close contact with the wafer includes placing the second mold over the wafer with the microlenses positioned in the microlens openings of the second mold.

4. The method according to claim 3 , wherein the microlens openings of the second mold are larger than the microlenses.

5. The method according to claim 1 , wherein the solder openings of the second mold are cylindrical through-holes.

6. The method according to claim 1 , wherein each of the microlenses transmits only a selected color of light.

7. The method according to claim 1 , wherein the semiconductor wafer includes a plurality of semiconductor devices, and the microlenses are aligned with respect to the substrate to couple radiant energy to the plurality of semiconductor devices.

8. The method according to claim 7 , wherein each of the microlenses has a radius of curvature and a focal length for semiconductor color imaging with said plurality of said semiconductor devices.

9. The method according to claim 1 wherein said microlenses are less than 10 micrometers in one dimension.

10. The apparatus of claim 1 wherein said microlenses are less than 1 micrometer in one dimension.

Assignees

• IBM

Inventors

• Jacobwitz Lawrence
• Buchwalter Stephen
• Decusatis Casimer
• Gruber Peter A
• Shih Da-Yuan

Classifications

• G02B3/0018

  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 title

• B29D11/00461

  Adjusting the refractive index, e.g. after implanting · CPC title

• G02F1/29

  for the control of the position or the direction of light beams, i.e. deflection · CPC title

• B29D11/00365

  Production of microlenses (lenticular sheets B29D11/00278) · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title