INJECTION MOLDED MICROOPTICS

• US 20080285136A1
• Filed: 06/17/2008
• Published: 11/20/2008
• Est. Priority Date: 08/02/2005
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DeCusatis, Casimer, Jacobowitz, Lawrence, Shih, Da-Yuan, Gruber, Peter A., Buchwalter, Stephen L.
• Application Number:
  US12/140,676
• Publication Number:
  US 20080285136A1
• Time in Patent Office: Days
• US Class Current: 359/619
• 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

1-19. -19. (canceled)

20. Apparatus for the injection molding and aligned transfer of wafer-scale microoptic elements, the apparatus compressing:

a template including at least one alignment key;

etching means for forming a patterned array of shaped cavities in the template;

a fill tool for scanning movement across the template, and including a plurality of dispensing heads interchangeable between scans for injecting one or more polymerizable materials into said cavities;

means for at least partially polymerizing said materials in said cavities to form injection molded microoptic elements in said cavities;

a target substrate;

an aligner tool for using said at least one alignment key to move said template into a defined position relative to said target substrate; and

a transfer tool for displacing the injection molded microoptic elements from the array of cavities onto the targeted substrate.

21. Apparatus according to claim 20, further comprising:

a tool for applying a release layer agent to the cavity surfaces to facilitate removing the molded microoptic elements from said cavities;

a crucible for providing a mixture of liquid materials, including said polymerizable materials, to the dispensing heads of the fill tool;

an inspection tool for inspecting the materials injected into the template cavities to confirm selected properties of said materials; and

a clamping fixture for securing said template to said substrate and maintaining a given alignment of said array of cavities and said substrate; and

wherein the means for at least partially polymerizing said materials in said cavities includes;

i) means for solidifying the materials in said cavities in the template; and

ii) illumination means for providing ultraviolet light to control the degree of polymerization of the materials in said template cavities.

22. Apparatus according to claim 21, further comprising:

a template cleaning tool for removing from the template materials used to fill the array of cavities, to allow reuse of the template; and

a thermal reflow oven for applying controlled temperatures of the formed microoptic elements to enable shape adjustment and void/gap filling to effect a contiguous web of elements of the array on the substrate; and

wherein the transfer tool includes a fixture frame, contact points, a base and separating means.

23. The apparatus of claim 20, wherein:

the injection-mold template is a photoimagable material layer, overlaying a carrier substrate, such that a decal process for fast turnaround time template formation, is enabled.

24. The apparatus of claim 20, wherein:

the cavities of the injection-mold template have shapes selected from the group including spherical, aspherical, cylindrical, ellipsoidal, paraboloidal, trapezoidal, rectangular, square, or other geometric morphologies and topologies.

25. An apparatus comprising:

a substrate containing semiconductor devices, and

a plurality of microoptic elements positioned on 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,

said microoptic elements containing polymers or glasses having optical properties and having surfaces shaped for enhancing one or more functions of said microoptic elements.

26. The apparatus of claim 25 wherein said microoptic elements are less than 10 micrometers in one dimension.

27. The apparatus of claim 25 wherein said microoptic elements are less than 1 micrometers in one dimension.

28. The apparatus of claim 25 wherein a plurality of said microelements contain polymers having different indices of refraction.

29. The apparatus of claim 25 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.