Anisotropic conductive treads for electrical connections in soft electronics

• US 10,612,172 B2
• Filed: 10/24/2017
• Issued: 04/07/2020
• Est. Priority Date: 10/24/2016
• Status: Active Grant

• Current Assignee: University of Louisville
• Original Assignee: University of Louisville
• Inventors: Harnett, Cindy
• Primary Examiner(s): Thompson, Timothy J
• Assistant Examiner(s): Miller, Rhadames Alonzo
• Application Number:
  US16/344,212
• Publication Number:
  US 20190257015A1
• Time in Patent Office: 896 Days
• CPC Class Codes: D05B 19/12 characterised by control of operation of machine
• CPC Class Codes: D05D 2303/40 Electronic or electrical components
• CPC Class Codes: D10B 2401/16 antistatic; conductive
• CPC Class Codes: H05K 1/00 Printed circuits
• CPC Class Codes: H05K 1/028 Bending or folding regions of flexible printed circuits H05K1/0283 takes precedence
• CPC Class Codes: H05K 1/038 Textiles used as reinforcing materials for organic insulating substrates H05K1/0366
• CPC Class Codes: H05K 1/118 specially for flexible printed circuits, e.g. using folded portions
• CPC Class Codes: H05K 1/141 One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 2201/09281 Layout details of a single conductor meander H05K2201/09263; layout details of angles or corners H05K2201/09272
• CPC Class Codes: H05K 2201/10287 Metal wires as connectors or conductors
• CPC Class Codes: H05K 3/00 Apparatus or processes for manufacturing printed circuits
• CPC Class Codes: H05K 3/10 in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
• CPC Class Codes: H05K 3/103 by bonding or embedding conductive wires or strips
• CPC Class Codes: H05K 3/4046 using auxiliary conductive elements, e.g. metallic spheres, eyelets, pieces of wire

Abstract

An embroidery machine with on-board electronics executing layout and alignment software provides for automated thread installation to establish textile-to-pad contact through the use of anisotropic conductive threads characterized by electrically conductive segments alternating with electrically insulating segments. Present embodiments provide for garments or other fabrics and textiles having flexible circuits integrated on a flexible substrate that bends and moves with the garment in a way not seen with stiff printed circuit boards, which may include multiple textile circuits attached to fabric to impart desired electronic features including connectivity to a printed circuit board external to a garment formed according to the present embodiments, as well as imparting electrical conductivity across seams of a garment sewn together from fabric, while maintaining electrical integrity of neighboring circuits on the same garment.

Claims

1. A method that uses a needle-directing machine having at least a needle, a needle bar, a head, an arm, and a processor that executes computer readable program instructions, the method being for attaching to a fabric having a thickness an electronic circuit arranged on a patch, the method comprising:

stitching a circuit to the fabric with anisotropic conductive thread having electrically conductive segments and electrically insulating segments;

wherein stitching the circuit to the fabric proceeds according to a predetermined path representing a pattern the anisotropic conductive thread travels through the fabric thickness to attach the patch to the fabric, and laterally across the fabric; and

further comprising, before the step of stitching the circuit to the fabric, storing, on a computer readable medium, program instructions that when executed by the processor configure the predetermined path for stitching the anisotropic conductive thread into the fabric such that at least one electrically conductive segments of anisotropic conductive thread travels through the fabric thickness where the patch is attached to the fabric.

2. The method of claim 1, further comprising causing the processor to execute the program instructions, thereby stitching the anisotropic conductive thread to the fabric according to the predetermined path.

3. The method of claim 1, further comprising forming holes in the patch through which only electrically conductive segments of anisotropic conductive thread pass.

4. The method of claim 1, wherein the fabric has at least one seam that separates a first side of the fabric from a second side of the fabric, and further comprising configuring the predetermined path to stitch anisotropic conductive thread from fabric on the first side of the at least one seam to fabric on the second side of the at least one seam.

5. The method of claim 1, wherein the electrically conductive segments and electrically insulating segments are alternating.

6. The method of claim 1, further comprising forming anisotropic conductive thread by sensitizing selected areas of non-conducting thread for plating, and then exposing the sensitized thread to a solution that contains silver nitrate.

7. A method that uses a needle-directing machine having at least a needle, a needle bar, a head, an arm, and a processor that executes computer readable program instructions, the method being for attaching to a fabric having a thickness a plurality of electronic circuits each being arranged on a patch, the method comprising:

stitching two or more circuits to the fabric with anisotropic conductive thread having electrically conductive segments and electrically insulating segments;

wherein stitching the circuits to the fabric proceeds according to a predetermined path representing a pattern the anisotropic conductive thread travels through the fabric thickness to attach each patch to the fabric, and laterally across the fabric;

wherein the electrically insulating segments are arranged such that an electrical connection is not formed between any two circuits; and

further comprising, before the step of stitching the circuit to the fabric, storing, on a computer readable medium, program instructions that when executed by the processor configures the predetermined path for stitching the anisotropic conductive thread into the fabric such that (i) at least one electrically conductive segments of anisotropic conductive thread travels through the fabric thickness where each patch is attached to the fabric, and (ii) at least one electrically insulating segment travels across the fabric between any two patches.

8. The method of claim 7, further comprising causing the processor to execute the program instructions, thereby stitching the anisotropic conductive thread to the fabric according to the predetermined path.

9. The method of claim 7, further comprising forming holes in the patch through which only electrically conductive segments of anisotropic conductive thread pass.

10. The method of claim 7, wherein the fabric has at least one seam that separates a first side of the fabric from a second side of the fabric, and further comprising configuring the predetermined path to stitch anisotropic conductive thread from fabric on the first side of the at least one seam to fabric on the second side of the at least one seam.

11. The method of claim 7, wherein the electrically conductive segments and electrically insulating segments are alternating.

12. The method of claim 7, further comprising forming anisotropic conductive thread by sensitizing selected areas of non-conducting thread for plating, and then exposing the thread to a solution that contains silver nitrate.

13. An article formed from a fabric, comprising:

at least two patches each being formed from a flexible substrate and each patch having an electronic circuit formed thereon;

wherein each circuit is electrically and mechanically connected to the article with anisotropic conductive thread having alternating electrically conductive segments and electrically insulating segments;

such that at least one electrically conductive segment passes through the substrate in a direction along a first spatial dimension and at least one electrically insulating segment extends between the at least two circuits moving in a second spatial dimension.

14. The article of claim 13, wherein the fabric forming the article has at least one seam that separates a first side of the fabric from a second side of the fabric, and wherein the anisotropic conductive thread is stitched from fabric on the first side of the at least one seam to fabric on the second side of the at least one seam.

15. The article of claim 13, further comprising a multi-pin electrical connection formed integrally with at least one of the circuits arranged for electrical connection to a printed circuit board.