KR20140121325A - stretchable electric device and manufacturing method of the same - Google Patents

Abstract

Disclosed are a stretchable electric device and a method to manufacture the same. The method to manufacture the same includes: a step of forming a mold substrate; a step of forming a stretchable substrate including a first flat surface on the mold substrate and a first corrugated surface outside the first flat surface; a step of removing the mold substrate; a step of forming corrugated wiring on the first corrugated surface; and a step of forming an electronic element connected to the corrugated wiring on the first flat surface.

Description

Stretchable electronic devices and methods of manufacturing same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic circuit and a method of manufacturing the same, and more particularly, to a flexible electronic circuit and a method of manufacturing the same.

The elastic electronic device can maintain the electrical function even if the substrate is expended by an externally applied stress. Flexible electronic devices have the potential to be applied to various fields such as sensors for robots, wearable communication devices, built-in / attached bio-devices, and next generation displays, beyond the limitations of simple bendable and / or flexible devices .

The flexible electronic device may have a structure capable of expanding metal wiring. The metal wiring may be formed in a wavy form by shrinkage of the stretchable substrate after being transferred to a pre-strained stretchable substrate surface. The metallization can provide the stretchability of the electronic device. However, the expansion electronic device can be limited in its ability to expand the metal wiring by the amount of pre-strain initially applied to the substrate. In addition, the wavy metal wiring has a disadvantage that it is difficult to apply a large area and secure reliability, because the process is complicated compared with a general semiconductor device fabrication process.

Other stretchable electronic devices may include wirings of conductive stretchable material instead of metal. Conductive stretching materials mainly include conductive materials such as conductive polymers, carbon nanotubes, and graphenes. However, the conductive stretchable material has a high expansion capability, but has a drawback that the electrical resistance is higher than that of the metal, and the fine patterning at the micrometer level is difficult

Another flexible electronic device may include a two-dimensional flat spring-like wire. The spring-like wiring is compatible with a semiconductor device process, which is a general wiring process, so that cost reduction and reliability can be easily ensured and high conductivity can be obtained. However, when the spring-shaped wiring is elongated or contracted, the amount of deformation is locally concentrated only at a specific portion of the wiring, causing breakage. Therefore, there is a limit to increase the expansion rate.

SUMMARY OF THE INVENTION The present invention provides a flexible electronic circuit capable of easily forming electronic devices and corrugated wiring, and a manufacturing method thereof.

Another technical problem is to provide a stretchable electronic circuit and a manufacturing method thereof that can improve the operation reliability and lifetime of electronic devices.

A method of manufacturing an elastic electronic circuit according to an embodiment of the present invention includes: forming a mold substrate; Forming a flexible substrate having a first flat surface on the mold substrate and a first corrugated surface outside the first planar surface; Removing the mold substrate; Forming a corrugated wiring on the first corrugated surface; And forming an electronic device connected to the corrugated wiring on the first flat surface.

According to an embodiment of the present invention, the flexible substrate includes: a low-stiffness elastic body having the first corrugated surface; And a high-stiffness body having an island shape on the low-rigidity elastic body and having the first flat surface, Block.

According to another embodiment of the present invention, the step of forming the flexible substrate includes: forming the highly rigid block on the mold substrate; And forming the low stiffness elastic body on the high rigidity block and the mold substrate.

According to an embodiment of the present invention, the highly rigid block may be formed by a photolithography method, a printing method, or a bonding method.

According to another embodiment of the present invention, the low stiffness elastic body may be formed by a spin coating method or a dropping method.

According to one embodiment of the present invention, the low stiffness elastic body may be formed of an addition type liquid silicone rubber (sylgard 184).

According to another example of the present invention, the high-rigidity block may be formed of a photosensitive resin (photopatternable regin, WL-5350).

According to an embodiment of the present invention, the low-rigidity elastic body is formed before the removal of the mold substrate, and the high-rigidity block may be formed after the mold substrate is removed.

According to another embodiment of the present invention, the high-rigidity block can be cured from the low-rigidity elastic body by laser light.

According to an embodiment of the present invention, the step of forming the mold substrate may include a photolithography process and a reflow process.

According to another example of the present invention, the step of forming the mold substrate may include a photolithography process using a gray scale photomask.

According to an embodiment of the present invention, the mold substrate includes: a mold body; And a photoresist layer disposed on the mold body, the photoresist layer having a second flat surface corresponding to the first flat surface and a second corrugated surface corresponding to the first corrugated surface.

According to another example of the present invention, the photoresist layer has a trench in which the second flat surface is formed below the second corrugated surface, and the highly rigid block may be formed in the trench.

According to an embodiment of the present invention, the method may further include forming an elastic protective layer on the electronic element, the corrugated wiring, and the flexible substrate.

According to another aspect of the present invention, there is provided an elastic electronic circuit comprising: a flexible substrate having a flat surface and a corrugated surface outside the flat surface; A corrugated wiring disposed on the corrugated surface of the flexible substrate; And an electronic device connected to the corrugated wiring and disposed on the flat surface. Here, the flat surface may have a higher hardness than the corrugated surface.

According to one embodiment of the present invention, the flexible substrate may comprise an elastomer.

According to another embodiment of the present invention, the elastomer may include PDMS (poly-dimethylsiloxane) or polyurethane.

According to an embodiment of the present invention, the flexible substrate includes: a low rigid elastic body having the corrugated surface; And a highly rigid block arranged in an island shape on the low rigidity elastic body and having the flat surface.

According to another example of the present invention, the low stiffness elastic body may comprise an addition type liquid silicone rubber (sylgard 184).

According to an embodiment of the present invention, the flat plate block may include a photopatternable regin (WL-5350).

According to an embodiment of the present invention, the flexible substrate includes a low rigidity elastic body and a high rigidity block. A corrugated wiring is formed on the low-rigidity elastic body, and an electronic element can be formed on the high-rigidity block. The high-rigidity block improves the operation reliability and lifetime of the electronic device, and facilitates formation of the electronic device. Therefore, the stretchable electronic circuit and the manufacturing method thereof according to the embodiment of the present invention can improve the productivity.

1 is a plan view showing a stretchable electronic circuit according to a first embodiment of the present invention.
2 is a cross-sectional view taken along the line II 'in Fig.
FIGS. 3 to 8 are process sectional views sequentially illustrating a method of manufacturing a flexible electronic circuit according to a first embodiment of the present invention, with reference to FIG.
9 is a cross-sectional view showing a flexible electronic circuit according to a second embodiment of the present invention.
10 to 15 are process sectional views showing a method of manufacturing a flexible electronic circuit according to a second embodiment of the present invention based on FIG.
Figs. 16 to 18 are process sectional views showing a method of manufacturing an electronic circuit according to a third embodiment of the present invention.

The foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the claimed invention. Therefore, the present invention is not limited to the embodiments described herein but may be embodied in other forms. The embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In this specification, when it is mentioned that a certain element includes an element, it means that it may further include other elements. In addition, each embodiment described and illustrated herein includes its complementary embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view showing a stretchable electronic circuit according to a first embodiment of the present invention. 2 is a cross-sectional view taken along line I-I 'of FIG.

1 and 2, a flexible electronic circuit according to a first embodiment of the present invention includes a flexible substrate 30, electronic components 40, corrugated wires 50, and an elastic protective layer 60 .

The flexible substrate 30 may include a low-rigidity elastic body 10 and high-rigidity blocks 20. The low stiffness elastic body 10 may have a first corrugated surface 12. The first corrugated surface 12 is the rugged upper surface of the low stiffness elastic body 10. The low rigidity elastic body 10 may have elasticity. The high rigidity blocks 20 may be arranged in an island shape on the low rigidity elastic body 10. The high stiffness blocks 20 may have a high mechanical stiffness as compared to the low stiffness elastic body 10. The high stiffness blocks 20 may be hard or rigid. The high stiffness blocks 20 may have a first flat surface 22. The stretchable substrate 30 may include an elastomer such as PDMS (Poly-Dimethylsiloxane) or polyurethane. For example, the low stiffness elastic body 10 may comprise of an addition type liquid silicone rubber (Sylgard 184). The high stiffness blocks 20 may comprise a photosensitive resin.

The electronic components 40 and the corrugated wires 50 may be mounted integrally on the flexible substrate 30. The electronic devices 40 may include a thin film transistor, a pixel electrode. The electronic elements 40 may be disposed on the first planar surface 22 of the high stiffness blocks 20. The first flat surface 22 may be a support surface for stably fixing the electronic devices 40. [ The electronic elements 40 can be fixed by the high rigidity blocks 20 even if the low rigid elastic body 10 is stretched. That is, the high-rigidity blocks 20 can protect the electronic elements 40 from the deformation of the low-rigidity elastic body 10. The high-rigidity blocks 20 can improve the operational reliability and lifetime of the electronic devices 40. [

The corrugated wires 50 may connect the electronic components 40. The corrugated wires 50 may be disposed on a portion of the high stiffness blocks 20 and on the low stiffness elastic body 10. The corrugated interconnects 50 may include metals such as copper, aluminum, tungsten, nickel, manganese, or silver, nanotubes, or graphene. The corrugated wires 50 can be bent up, down, left, and right along the first corrugated surface 12 on the low-rigidity elastic body 10. The corrugated wirings 50 can be expanded and contracted in the horizontal direction together with the low-rigidity elastic body 10 by an external tensile force.

The elastic protective layer 60 covers the flexible substrate 30, the electronic elements 40, and the corrugated wires 50. The stretchable protective layer 60 may comprise an elastomer, a polymer, an elastic thin film, or an organic thin film.

A method of manufacturing the flexible electronic circuit according to the first embodiment of the present invention will now be described.

FIGS. 3 to 8 are process sectional views sequentially illustrating a method of manufacturing a flexible electronic circuit according to a first embodiment of the present invention, with reference to FIG.

Referring to FIG. 3, a mold substrate 70 is provided. The mold substrate 70 may include a mold body 72 and a photoresist layer 74. The mold body 72 may comprise a silicon wafer. A photoresist layer 74 may be disposed on the mold body 72. The photoresist layer 74 may have a second corrugated surface 76 and a second flat surface 78. The second corrugated surface 76 and the second flat surface 78 may be formed at the same level on top of the photoresist layer 74. According to one example of the present invention, the second corrugated surface 76 and the second flat surface 78 may be formed by a photolithography process and a reflow process of the photoresist layer 74. For example, the second corrugated surface 76 of the photoresist layer 74 formed in the photolithographic process may have a protruding shape at right angles. A rounded second corrugated surface 76 can be formed through the reflow process. According to another example of the present invention, the second corrugated surface 76 and the second flat surface 78 may be manufactured by a photolithography process using a grayscale photomask. Although not shown, the scraper mask may have half-tone masking patterns at portions corresponding to the second corrugated surface 76 and black or white masking patterns at portions corresponding to the second flat surface 78.

4, the high rigidity block 20 is bonded onto the second flat surface 78 of the mold substrate 70. As shown in Fig. The high rigidity block 20 may be formed by a photolithography method, a printing method, or a bonding method. The high stiffness block 20 may comprise a photosensitive resin.

Referring to FIG. 5, a low rigid elastic body 10 is formed on the mold substrate 70 and the high rigidity blocks 20. The low rigidity elastic body 10 may be formed by a spin coating or a dropping method. The low rigidity elastic body 10 may comprise an addition type liquid silicone rubber (Sylgard 184).

Referring to FIG. 6, the mold substrate 70 is removed. The photoresist layer 74 of the mold substrate 70 may be removed by an organic solvent.

Referring to FIG. 7, corrugated wires 50 are formed on the low-rigidity elastic body 10 and the high-rigidity blocks 20. The step of forming the corrugated wirings 50 may include a metal deposition process, a photolithography process, and an etching process. The metal deposition process may include a chemical vapor deposition process, or a physical vapor deposition process. The corrugated wires 50 may be formed up, down, left and right along the first corrugated surface 12 of the low stiffness elastic body 10.

Referring to FIG. 8, an electronic device 40 is formed on the high-rigidity block 20. The electronic elements 40 may be connected to the corrugated wires 50. The step of forming the electronic device 40 may include a deposition process, an ion implantation process, a photolithography process, or an etching process. The first flat surface 22 of the high rigidity block 20 may be the bottom surface of the electronic device 40. The first flat surface 22 can provide a plane capable of stably forming the electronic device 40. The electronic elements 40 can be formed with high reliability.

Referring again to FIG. 2, an elastic protective layer 60 is formed on the low-rigidity elastic body 10, the high-rigidity blocks 20, the electronic device 40, and the corrugated wirings 50. The stretchable protective layer 60 may be formed by a chemical vapor deposition method, a physical vapor deposition method, a spin coating method, a sol-gel method, or a printing method. The stretchable protective layer 60 may comprise an elastomer, a polymer, an elastic thin film, or an organic thin film.

(Second Embodiment)

9 is a cross-sectional view showing a flexible electronic circuit according to a second embodiment of the present invention.

Referring to FIG. 9, the flexible electronic circuit according to the second embodiment of the present invention may include a flexible substrate 30 having a high rigid block 20 protruding above a low rigid elastic body 10. The first corrugated surface 12 of the low stiffness elastic body 10 may be located below the first flat surface 22 of the high stiffness block 20. The electronic device 40 may be disposed on the first flat surface 22 and the corrugated lines 50 may be disposed on the first corrugated surface 12. The electronic device 40 may be disposed at a level higher than the corrugated lines 50. In the second embodiment, the high rigidity block 20 in the first embodiment protrudes to the upper portion of the low rigidity elastic body 10.

10 to 15 are process sectional views showing a method of manufacturing a flexible electronic circuit according to a second embodiment of the present invention.

Referring to Fig. 10, a mold substrate 70 is provided. The mold substrate 70 may include a mold body 72 and a photoresist layer 74 on the mold body 72. The photoresist layer 74 may have a trench 79. The photoresist layer 74 may have a second corrugated surface 76 and a second flat surface 78. The second flat surface 78 may be positioned below the second corrugated surface 76. The second flat surface 78 may be formed at the bottom of the trench 79. According to one example of the present invention, the step of forming the photoresist layer 74 may include a photolithography process and a reflow process. Further, according to another example of the present invention, the step of forming the photoresist layer 74 may include a photolithography process using a gray scale photomask.

Referring to FIG. 11, a high-rigidity block 20 is formed in the trench 79. The high stiffness block 20 may comprise a photosensitive resin.

Referring to FIG. 12, a low rigidity elastic body 10 is formed on the high rigidity block 20 and the mold substrate 70. The low rigidity elastic body 10 may be formed by a spin coating or a dropping method. The low rigidity elastic body 10 may comprise an addition type liquid silicone rubber (Sylgard 184).

Referring to Fig. 13, the mold substrate 70 is removed. The photoresist layer 74 of the mold substrate 70 may be removed by an organic solvent.

Referring to FIG. 14, corrugated wirings 50 are formed on a portion of the high-rigidity block 20 and the low-rigidity elastic body 10. The step of forming the corrugated wirings 50 may include a metal deposition process, a photolithography process, and an etching process.

Referring to FIG. 15, an electronic device 40 is formed on a high-rigidity block 20. The step of forming the electronic device 40 may include a deposition process, an ion implantation process, a photolithography process, or an etching process. The first flat surface 22 of the high rigidity block 20 may be the bottom surface of the electronic device 40. The first flat surface 22 can provide a plane capable of stably forming the electronic device 40. The electronic elements 40 can be formed with high reliability. The electronic device 40 may be formed at a level above the corrugated lines 50.

9, an elastic protective layer 60 is formed on the low-rigidity elastic body 10, the high-rigidity block 20, the electronic device 40, and the corrugated wirings 50. The stretchable protective layer 60 may be formed by a chemical vapor deposition method, a physical vapor deposition method, a spin coating method, a sol-gel method, or a printing method.

(Third Embodiment)

Figs. 16 to 18 are process sectional views showing a method of manufacturing an electronic circuit according to a third embodiment of the present invention.

Referring again to FIG. 3, a mold substrate 70 is provided. The mold substrate 70 may include a mold body 72 and a photoresist layer 74 on the mold body 72. The photoresist layer 74 may have a second corrugated surface 76 and a second flat surface 78. The second corrugated surface 76 and the second flat surface 78 may be formed at the same level on top of the photoresist layer 74.

Referring to FIG. 16, a low rigid elastic body 10 is formed on a mold substrate 70. The low rigid elastic body 10 can be formed by a spin coating or a dropping method. The low stiffness elastic body 10 may comprise. The low stiffness elastic body 10 may have a first corrugated surface 12 and a first flat surface 22.

Referring to Fig. 17, the mold substrate 70 is removed. The photoresist layer 74 of the mold substrate 70 may be removed by an organic solvent.

Referring to FIG. 18, the low rigid elastic body 10 of the first flat surface 22 is partly solidified to form the high rigid block 20. FIG. The high rigidity block 20 can be formed by the laser light 14. [

Referring again to FIG. 7, corrugated wires 50 are formed on the low-rigidity elastic body 10 and the high-rigidity blocks 20. The step of forming the corrugated wirings 50 may include a metal deposition process, a photolithography process, and an etching process.

Referring again to Fig. 8, an electronic device 40 is formed on the high-rigidity block 20. Fig. The electronic elements 40 may be connected to the corrugated wires 50. The step of forming the electronic device 40 may include a deposition process, an ion implantation process, a photolithography process, or an etching process.

2, an elastic protective layer 60 is formed on the low-rigidity elastic body 10, the high-rigidity blocks 20, the electronic device 40, and the corrugated wirings 50. The stretchable protective layer 60 may be formed by a chemical vapor deposition method, a physical vapor deposition method, a spin coating method, a sol-gel method, or a printing method.

The present invention has been described with reference to the preferred embodiments. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

10: low rigidity elastic body 12: first corrugated side
14: laser beam 20: high rigidity block
22: first flat surface 30: stretchable substrate
40: electronic device 50: corrugated wiring
60: stretchable protective layer 70: mold substrate
72: mold body 74: photoresist layer
76: second corrugated surface 78: second flat surface
79: trench

Claims (20)

Forming a mold substrate;
Forming a flexible substrate having a first flat surface on the mold substrate and a first corrugated surface outside the first planar surface;
Removing the mold substrate;
Forming a corrugated wiring on the first corrugated surface; And
And forming an electronic element connected to the corrugated wiring on the first flat surface. The method according to claim 1,
The stretchable substrate includes:
A low stiffness elastic body having the first corrugated surface; And
And a high-rigidity block arranged in an island shape on the low-rigidity elastic body and having the first flat surface. 3. The method of claim 2,
Wherein the step of forming the flexible substrate comprises:
Forming the highly rigid block on the mold substrate; And
And forming the low rigid elastic body on the high rigid block and the mold substrate. The method of claim 3,
Wherein the high-rigidity block is formed by a photolithography method, a printing method, or a bonding method. The method of claim 3,
Wherein the low-rigidity elastic body is formed by a spin coating or dropping method. 3. The method of claim 2,
Wherein the low rigidity elastic body is formed of an addition type liquid silicone rubber. 3. The method of claim 2,
Wherein the high-rigidity block is formed of a photosensitive resin. 3. The method of claim 2,
Wherein the low rigidity elastic body is formed before removal of the mold substrate, and the high rigidity block is formed after removal of the mold substrate. 9. The method of claim 8,
Wherein the high-rigidity block is cured from the low-rigidity elastic body of the first flat surface by laser light. The method according to claim 1,
Wherein the forming of the mold substrate includes a photolithography process and a reflow process. The method according to claim 1,
Wherein the step of forming the mold substrate includes a photolithography process using a gray scale photomask. The method according to claim 1,
Wherein the mold substrate comprises:
Mold body; And
And a photoresist layer disposed on the mold body and having a second flat surface corresponding to the first flat surface and a second corrugated surface corresponding to the first corrugated surface. 13. The method of claim 12,
Wherein the photoresist layer has a trench in which the second flat surface is formed below the second corrugated surface,
And the high-rigidity block is formed in the trench. The method according to claim 1,
Further comprising the step of forming an elastic protective layer on the electronic element, the corrugated wiring, and the stretchable substrate. A flexible substrate having a flat surface and a corrugated surface outside the flat surface;
A corrugated wiring disposed on the corrugated surface of the flexible substrate; And
And an electronic device connected to the corrugated wiring and disposed on the flat surface,
Wherein the flat surface has a higher hardness than the corrugated surface. 16. The method of claim 15,
Wherein the flexible substrate comprises an elastomer. 17. The method of claim 16,
Wherein said elastomer comprises PDMS (Poly-Dimethylsiloxane) or polyurethane. 16. The method of claim 15,
The stretchable substrate includes:
A low stiffness elastic body having the corrugated surface; And
And a high-rigidity block arranged in an island shape on the low-rigidity elastic body and having the flat surface. 19. The method of claim 18,
Wherein the low rigidity elastic body comprises an addition type liquid silicone rubber. 19. The method of claim 18,
Wherein the flat plate block comprises a photosensitive resin.

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