Microdisplay packaging system

• US 8,680,572 B2
• Filed: 10/13/2011
• Issued: 03/25/2014
• Est. Priority Date: 12/31/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: O'Connor, Michael, Springett, Thomas W., Ward-Dolkas, Paul C.
• Primary Examiner(s): MITCHELL, JAMES M
• Application Number:
  US13/273,011
• Publication Number:
  US 20120032205A1
• Time in Patent Office: 894 Days
• Field of Search: 257/88, 257/99, 257/116
• US Class Current: 257/116
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 1/136277 formed on a semiconductor substrate, e.g. of silicon
• CPC Class Codes: G02F 2201/54 Arrangements for reducing warping-twist
• CPC Class Codes: G02F 2203/60 Temperature independent

Abstract

Some embodiments provide a microdisplay integrated circuit (IC), a substantially transparent protective cover coupled to the microdisplay IC, and a base coupled to the microdisplay IC. Thermal expansion characteristics of the base may be substantially similar to thermal expansion characteristics of the protective cover. According to some embodiments, at least one set of imaging elements is fabricated on an upper surface of a semiconductor substrate, and a base is affixed to a lower surface of the semiconductor substrate to generate substantially negligible mechanical stress between the semiconductor substrate and the base.

Claims

1. A device comprising:

a microdisplay integrated circuit (IC);

a substantially transparent protective cover coupled to the microdisplay IC; and

a chip carrier defining an opening,

wherein the microdisplay IC comprises;

a semiconductor substrate;

a pixel cell array fabricated within upper layers of semiconductor substrate, the pixel cell array including a plurality of pixel cells arranged in a two-dimensional grid;

a plurality of pixel electrodes, each associated with a respective one of the plurality of pixel cells;

a light switching layer in contact with the plurality of pixel electrodes; and

an electrode disposed between the light switching layer and the substantially transparent protective cover; and

wherein the cover extends over the plurality of pixel cells and partially into, fully into, partially through or fully through the opening defined by the chip carrier; and

wherein the chip carrier comprises conductors to carry electrical signals.

2. A device according to claim 1, further comprising:

a base coupled to the microdisplay IC.

3. A device according to claim 2, further comprising:

a heat sink coupled to the base.

4. A device according to claim 2, wherein the chip carrier comprises material that provides a low thermal resistance path for cooling the microdisplay IC and base during operation.

5. A device according to claim 4, wherein the material is yielding so as to absorb mechanical deflections of the microdisplay IC and the base.

6. A device according to claim 2, wherein a coefficient of thermal expansion of the base matches a coefficient of thermal expansion of the semiconductor substrate more closely than a coefficient of thermal expansion of the chip carrier matches the coefficient of thermal expansion of the semiconductor substrate.

7. A device according to claim 1, wherein the chip carrier is coupled to the microdisplay IC.

8. A device according to claim 7, wherein the microdisplay IC comprises:

a bonding surface, the bonding surface comprising conductors, and

wherein the conductors of the bonding surface contact respective ones of the conductors of the chip carrier.

9. A device according to claim 1, wherein the chip carrier possesses a coefficient of thermal expansion similar to a coefficient of thermal expansion of the semiconductor substrate.

10. A device according to claim 1, wherein each of the plurality of pixel cells corresponds to an image pixel of the microdisplay IC.

11. A device according to claim 10, wherein the light switching layer comprises a layer of liquid crystal.