Pre-patterned substrate for organic thin film transistor structures and circuits and related method for making same

• US 6,946,677 B2
• Filed: 06/14/2002
• Issued: 09/20/2005
• Est. Priority Date: 06/14/2002
• Status: Expired due to Term

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ostergard, Toni
• Primary Examiner(s): CRANE, SARA W
• Application Number:
  US10/172,796
• Publication Number:
  US 20030230747A1
• Time in Patent Office: 1,194 Days
• Field of Search: 257/40, 438/99, 438/82
• US Class Current: 257/40
• CPC Class Codes: H10K 10/462 Insulated gate field-effect transistors [IGFETs]
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 71/135 using ink-jet printing
• CPC Class Codes: H10K 99/00 Subject matter not provided for in other groups of this subclass

Abstract

Grooves in a desired circuit configuration are formed in the surface of a substrate to pre-pattern the area to receive material forming an organic thin film transistor (OTFT) structure and interconnecting conductive paths. The OTFT material is deposited in the pre-patterned area using printing techniques such as ink jet printing. In one embodiment, the grooves are formed in the surface substrate during the injection molding process of the substrate. Inter-exchangeable device covers carry different substrates to provide different functionalities of an electronic device with which the covers are used.

Claims

1. A substrate for carrying an organic thin film transistor (OTFT) structure, comprising:

said substrate having a thickness and a surface of arbitrary size and shape, and

at least one groove in said substrate surface having a predefined pattern for carrying the organic material comprising the OTFT structure, said groove predefined pattern defining the spreading area of said organic material.

2. The substrate as defined in claim 1 further comprising said groove predefined pattern receiving the source, drain, gate, insulating layer and semiconductor layer materials to form the desired OTFT structure.

3. The substrate as defined in claim 2 further comprising other grooves in a desired pattern for receiving organic conductive material defining circuit paths to interconnect the OTFT structures to produce an electrical circuit.

4. The substrate as defined in claim 1 wherein said substrate further comprises an injection molded substrate and said groove predefined pattern further comprises predefined injection molded grooves.

5. The substrate as defined in claim 2 wherein the OTFT structure further comprises printed respective source, drain, gate, insulating layer and semiconductor layer materials in said groove predefined pattern.

6. The substrate as defined in claim 2 wherein the OTFT structure further comprises inkjet printed respective source, drain, gate, insulating layer and semiconductor layer materials in said groove predefined pattern.

7. The substrate as defined in claim 1 wherein said at least one groove in the substrate is a hot embossed groove.

8. The substrate as defined in claim 1 wherein said at least one groove having a predefined pattern for carrying the OTFT structure further comprises a desired electrical circuit function pattern.

9. The substrate as defined in claim 8 wherein the desired electrical circuit function pattern further comprises a parallel-to-serial converter electrical circuit function.

10. The substrate as defined in claim 8 wherein the desired electrical circuit function pattern further comprises a serial-to-parallel converter electrical circuit function.

11. The substrate as defined in claim 8 further comprising said substrate being carried by a first inter-exchangeable cover of a first portable electronic device and comprising an interface between input/output operative functions and operational circuitry of the electronic device to carry out a first intended functionality.

12. The substrate as defined in claim 11 further comprising said substrate being printed with a different pattern and carried by a second inter-exchangeable cover used with said first portable electronic device to carry out a second intended functionality different than said first intended functionality when said first portable electronic device first inter-exchangeable cover is changed to said second inter-exchangeable cover.

13. A method for making a substrate for carrying the organic material comprising an organic thin film transistor (OTFT) structure, comprising the steps of:

providing a substrate having a thickness and a surface of arbitrary size and shape;

providing at least one groove having a predefined pattern in the surface of the substrate for carrying the OTFT structure, said groove predefined pattern defining the spreading area of the organic material.

14. The method as defined in claim 13 further comprising the steps of:

injection molding the substrate; and

defining the grooves in the desired pattern during the injection molding process.

15. The method as defined in claim 13 wherein the step of defining grooves further comprises defining a top-gate OTFT structure.

16. The method as defined in claim 13 wherein the step of defining grooves further comprises defining a bottom-gate OTFT structure.

17. The method as defined in claim 13 further comprising the step of injection molding a flexible substrate.

18. The method as defined in claim 13 wherein the step of defining grooves further comprises defining a desired circuit pattern to carry out a corresponding desired operational circuit functionality.

19. The method as defined in claim 13 further comprising the step of depositing organic and inorganic material defining the source, drain and gate electrodes and the insulating layer and the semiconductor layer in the grooves to form the OTFT structure.

20. The method as defined in claim 19, wherein the step of depositing further comprises printing the organic and inorganic material on the substrate surface.

21. The method as defined in claim 19 further comprising depositing the material by ink-jet printing.