Injection molded microoptics

• US 9,490,408 B2
• Filed: 09/13/2013
• Issued: 11/08/2016
• Est. Priority Date: 08/02/2005
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jacobowitz, Lawrence, Buchwalter, Stephen, DeCusatis, Casimer, Gruber, Peter A., Shih, Da-Yuan
• Primary Examiner(s): CARPENTER, ROBERT K
• Application Number:
  US14/026,598
• Publication Number:
  US 20140084314A1
• Time in Patent Office: 1,152 Days
• Field of Search: 257/432
• US Class Current: 1/1
• CPC Class Codes: B29D 11/00307 Producing lens wafers
• CPC Class Codes: B29D 11/00365 Production of microlenses lenticular sheets B29D11/00278
• CPC Class Codes: B29D 11/00461 Adjusting the refractive index, e.g. after implanting
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 3/0056 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: G02F 1/137 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
• CPC Class Codes: G02F 1/29 for the control of the position or the direction of light beams, i.e. deflection
• CPC Class Codes: H01L 27/14627 Microlenses
• CPC Class Codes: H01L 27/14685 Process for coatings or optical elements
• CPC Class Codes: H01L 31/02327 the optical elements being integrated or being directly associated to the device, e.g. back reflectors optical coatings H01L31/0216
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

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.

Claims

1. An apparatus comprising:

a substrate containing semiconductor devices, and

a plurality of molded, spectrally absorptive microoptic elements positioned on and extending above said substrate and spaced apart from one another by a predetermined distance and aligned with respect to said substrate to couple radiant energy to a plurality of said semiconductor devices,

each of said molded microoptic elements comprising optical polymers or glasses having a specified molded shaped surface design and including a color absorbing filter integrated into the optical polymers or glasses of the each molded microoptic element to form a spectrally absorptive microlens, wherein said each molded microoptic element transmits only a selected color of light, and each of said molded microoptic elements having a radius of curvature and a focal length for semiconductor color imaging with said plurality of said semiconductor devices.

2. The apparatus of claim 1 wherein said microoptic elements are less than 10 micrometers in one dimension.

3. The apparatus of claim 1 wherein said microoptic elements are less than 1 micrometer in one dimension.

4. The apparatus of claim 1 wherein a plurality of said microelements contain polymers having different indices of refraction.

5. The apparatus of claim 1 further including a plurality of C4 solder bumps positioned on said substrate and spaced apart from one another by a predetermined distance and aligned with respect to said substrate to couple electrical signals to a plurality of said semiconductor devices.

6. The apparatus according to claim 1, wherein the molded microoptic elements comprise liquid crystal materials formed into an active lens array with electronically variable focal length and depth of focus.

7. The apparatus according to claim 6, wherein:

the molded microoptic elements comprise injected molded microoptic elements and are aspheric;

the color absorbing filters comprise an array of color filters integrated into the microoptic elements; and

said specified molded shaped surface design includes a molded shaped upper surface of the molded microoptic elements positioned above said substrate.

8. The apparatus according to claim 6, further comprising an interface layer between the semiconductor device and the molded microoptic elements providing planarization, refractive index matching to reduce interfacial reflection loss, and adhesion of the molded microoptic elements.

9. The apparatus according to claim 1, further including solder interconnects molded onto the substrate for making electrical contacts to a packaging substrate.

10. The apparatus according to claim 1, wherein the plurality of molded microoptic elements comprise a single layer of aspheric microlenses.

11. The apparatus according to claim 1, wherein the molded microoptic elements further comprises photoiniators and photoreactive agents.