Solid state light sheet and encapsulated bare die semiconductor circuits with electrical insulator

• US 7,952,107 B2
• Filed: 05/26/2009
• Issued: 05/31/2011
• Est. Priority Date: 03/29/2004
• Status: Expired due to Fees

• Current Assignee: Articulated Technologies, LLC
• Original Assignee: Lumachip, Inc.
• Inventors: Nelson, Gregory Victor, Daniels, John James
• Primary Examiner(s): Richards; N Drew
• Assistant Examiner(s): Dulka; John P
• Application Number:
  US12/472,269
• Publication Number:
  US 20100084665A1
• Time in Patent Office: 735 Days
• Field of Search: 257/99, 257/100, 257/735, 257/79, 257/80, 257/88, 257/89, 257/443, 257/E33.046, 257/E33.066, 257/E33.064, 438/22, 438/34, 438/46, 438/127, 438/455
• US Class Current: 257/80
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: H01L 24/75 Apparatus for connecting with bump connectors or layer connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/12044 OLED
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin

Abstract

An electronically active sheet includes a bottom substrate having a bottom electrically conductive surface. A top substrate having a top electrically conductive surface is disposed facing the bottom electrically conductive surface. An electrical insulator separates the bottom electrically conductive surface from the top electrically conductive surface. At least one bare die electronic element is provided having a top conductive side and a bottom conductive side. Each bare die electronic element is disposed so that the top conductive side is in electrical communication with the top electrically conductive surface and so that the bottom conductive side is in electrical communication with the bottom electrically conductive surface.

Claims

1. An electronically active sheet, comprising:

a bottom substrate having a bottom electrically conductive surface;

a top substrate having a top electrically conductive surface disposed facing the bottom electrically conductive surface;

at least one bare die electronic element having a top conductive side and a bottom conductive side, said at least one bare die electronic element disposed so that the top conductive side is in direct face-to-face electrical communication with the top electrically conductive surface and so that the bottom conductive side is in direct face-to-face electrical communication with the bottom electrically conductive surface; and

an electrical insulator separating the bottom electrically conductive surface from the top electrically conductive surface and being effective to enable said at least one bare die electronic element to be forced through the electrical insulator and enable the direct face-to-face contact between the top conductive side and the top electrically conductive surface and to enable the direct face-to-face contact between the bottom conductive side and the bottom electrically conductive surface.

2. An electronically active sheet according to claim 1;

wherein the electrical insulator comprises a hotmelt adhesive.

3. An electronically active sheet according to claim 1;

wherein said at least one bare die electronic element is embedded in the electrical insulator with the top conductive side and the bottom conductive side left uncovered by the electrical insulator so that the electrical insulator binds the top substrate to the bottom substrate with the top conductive side of said at least one bare die electronic element in electrical communication with the top electrically conductive pattern of the top substrate and so that the bottom conductive side of said at least one bare die electronic element is in electrical communication with the bottom conductive pattern of the bottom substrate.

4. An electronically active sheet according to claim 1;

wherein said at least one electronic element comprises a solid state semiconductor light emitting diode bare die.

5. An electronically active sheet according to claim 1;

wherein said at least one bare die electronic element includes a first conductor and a second conductor both disposed on either the top conductive side and the bottom conductive side, and wherein said bare die electronic element is disposed so that the first conductor and the second conductor are in electrical communication with respective wiring lines formed on either the top substrate and the bottom substrate.

6. An electronically active sheet according to claim 1;

wherein the bare die electronic element comprises a plurality of individual bare die LED elements; and

the bottom electrically conductive surface and the top electrically conductive surface comprise a respective x and y wiring grid for selectively addressing said individual bare die LED elements for forming addressable display elements.

7. An electronically active sheet according to claim 6;

wherein the plurality of individual bare die LED elements include different types of bare die having different electrical and light emitting characteristics so that when an AC voltage is applied to the top conductive pattern and the bottom conductive pattern the intensity of light emission can be controlled for the different types of bare die to control the intensity and color of emitted light.

8. An electronically active sheet according to claim 7;

wherein the plurality of individual bare die LED elements form a backlight for a liquid crystal display, and wherein the plurality of different types of bare die are addressably controlled to vary the intensity and color of emitted light at locations of the backlight depending on an image being displayed on the liquid crystal display.

9. An electronically active sheet according to claim 6;

wherein the top conductive pattern includes more highly conductive, more opaque printed lines and less highly conductive, more transparent windows printed on the top substrate.

10. An electronically active sheet according to claim 9, further comprising;

an electrically insulative coating applied on at least portions of the more highly conductive, more opaque printed lines to reduce cross talk between the addressable display elements.

11. An electronically active sheet according to claim 1;

further comprising a phosphor provided in or on at least one of the top substrate and the bottom substrate, or formed in the electrical insulator, said phosphor being optically stimulated by a radiation emission of a first wavelength from the light active semiconductor element to emit light of a second wavelength.

12. An encapsulated bare die semiconductor electronic circuit comprising:

a first substrate having bottom side surface having at least a first and a second conductive line;

a bare die semiconductor electronic circuit element having a first electrode and a second electrode disposed on an obverse side; and

an adhesive encapsulating and adhering said bare die semiconductor electronic circuit element to said first substrate so that said first electrode is in electrical communication with said first conductive line and said second electrode in electrical communication with said second conductive line, the adhesive being an electrical insulator and being effective to enable said bare die semiconductor electronic circuit element to be forced through the electrical insulator and enable a direct face-to-face contact between said first electrode and said first conductive line and to enable a direct face-to-face contact between said second electrode and said second conductive line.

13. An encapsulated bare die semiconductor electronic circuit according to claim 12;

further comprising a second substrate disposed adjacent to the first substrate and bound to the first substrate by the adhesive.

14. An encapsulated bare die semiconductor electronic circuit according to claim 13;

wherein said second substrate includes a top side surface having a third conductive line;

said bare die semiconductor electronic circuit element includes a third electrode disposed on a reverse side; and

wherein said adhesive encapsulates and adheres said bare die semiconductor electronic circuit element to said second substrate so that said third electrode is in electrical communication with said third conductive line.

15. An encapsulated bare die semiconductor electronic circuit according to claim 13, further comprising, an electrically conductive through-hole disposed in either said first substrate and said second substrate for electrically connecting said bare die semiconductor electronic circuit element to a conductive element disposed on a top side surface of the first substrate or on a bottom side surface of the second substrate.

16. An encapsulated bare die semiconductor electronic circuit according to claim 12;

further comprising a second bare die semiconductor electronic circuit element having at least one electrode; and

wherein said adhesive encapsulates and adheres said second bare die semiconductor electronic circuit element to said first substrate so that said at least one electrode is in electrical communication with at least one of the first electrode and the second electrode through the respective first and second conductive line.