KR20210096913A - Stretchable substrate - Google Patents

Abstract

According to an embodiment of the present invention, a stretchable substrate comprises: a first stretchable base; a second stretchable base disposed on the first stretchable base; and a wiring disposed on at least one of the first stretchable base or the second stretchable base. Porosity of the first stretchable base is bigger than that of the second stretchable base, and the second stretchable base is an elongation limit base elongated within a predetermined range.

Description

Stretchable substrate {STRETCHABLE SUBSTRATE}

The present invention relates to a stretchable substrate, and more particularly, to a base of the stretchable substrate.

A stretchable substrate is a next-generation electronic device that operates without losing device characteristics even when the base is stretched or bent, and can maintain device characteristics even when external force is removed. Stretchable substrates are attracting attention as a core component material for implementing wearable electronic devices, electronic skin, Internet of Things, electronic devices for vehicles, and intelligent robots. In addition, the stretchable substrate may be applied to a stretchable display, a stretchable solar cell, a stretchable battery/energy harvest, and the like.

In order to implement a stretchable substrate, a base that is elastically stretched and a wiring disposed on the base are required. The elastically stretchable base may be implemented using a stretchable material such as polydimethylsiloxane (PDMS) or polyurethane (PU).

When the stretchable substrate is applied to a wearable electronic device, the stretchable substrate may be directly attached to the skin. At this time, if the air permeability between the skin and the stretchable substrate is not smooth, sweat from the skin is not discharged to the outside and stays in the stretchable substrate, and thus the user may feel a foreign body feeling and discomfort.

In order to increase the air permeability between the skin and the stretchable substrate, the application of a porous base has been attempted, but if the stretchable substrate is repeatedly stretched, the porous base may be torn or the junction between the porous base and the electrode may be weakened, which may damage the electrode. there is.

An object of the present invention is to provide a stretchable substrate having air permeability and stably bonding electrodes.

A stretchable substrate according to an embodiment of the present invention includes a first stretchable base, a second stretchable base disposed on the first stretchable base, the first stretchable base, and the second stretchable base. and a wiring disposed on at least one of the stretchable bases, wherein the porosity of the first stretchable base is greater than the porosity of the second stretchable base, and the second stretchable base is stretched within a predetermined range It is an extension-limiting base.

The first stretchable base may be a porous elastic base having a porosity of 20 to 60%.

The average diameter of the pores of the first stretchable base may be 10 to 100㎛.

The predetermined range may be 20 to 30% of the width of the second stretchable base.

The second stretchable base may include an elastic base and an elongation control structure molded in the elastic base.

The elongation control structure may include a fiber mat or a mesh film having a higher Young's modulus than the elastic base.

The diameter of the fibers constituting the fiber mat may be 0.3 to 1 μm.

At least one of the fiber mat and the mesh film may include at least one of polyimide and polyethylene terephthalate.

At least a portion of the first stretchable base, the second stretchable base, and the wiring may be embedded in a resin including silicon.

The wiring may include a repeating curved pattern.

The wiring may include a polyimide layer and a metal layer disposed on the polyimide layer.

According to an embodiment of the present invention, a stretchable substrate may be obtained. In particular, according to an embodiment of the present invention, it is possible to obtain a stretchable substrate having excellent breathability and good wearability of the user. In addition, according to the embodiment of the present invention, it is possible to obtain a stretchable substrate that is easy to manufacture, has high durability, and has a low possibility of disconnection. In addition, according to an embodiment of the present invention, it is possible to obtain a stretchable substrate having a strain limiting function.

1 is a cross-sectional view of a stretchable substrate according to an embodiment of the present invention.
2 is a top view of a stretchable substrate according to an embodiment of the present invention.
3 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention.
4 is a perspective view of a first stretchable base according to an embodiment of the present invention.
5 is a perspective view of a second stretchable base according to an embodiment of the present invention.
6 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention.
7 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention.
8 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical spirit of the present invention is not limited to some embodiments described, but may be implemented in various different forms, and within the scope of the technical spirit of the present invention, one or more of the components may be selected among the embodiments. It can be combined and substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be generally understood by those of ordinary skill in the art to which the present invention pertains, unless specifically defined and described explicitly. It may be interpreted as a meaning, and generally used terms such as terms defined in advance may be interpreted in consideration of the contextual meaning of the related art.

In addition, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In the present specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when it is described as "at least one (or one or more) of A and (and) B, C", it is combined with A, B, C It may include one or more of all possible combinations.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used.

These terms are only for distinguishing the component from other components, and are not limited to the essence, order, or order of the component by the term.

And, when it is described that a component is 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also with the component It may also include a case of 'connected', 'coupled' or 'connected' due to another element between the other elements.

In addition, when it is described as being formed or disposed on "above (above) or under (below)" of each component, the top (above) or bottom (below) is one as well as when two components are in direct contact with each other. Also includes a case in which another component as described above is formed or disposed between two components. In addition, when expressed as "upper (upper) or lower (lower)", the meaning of not only an upper direction but also a lower direction based on one component may be included.

The stretchable substrate according to an embodiment of the present invention operates without losing the characteristics of the device even when the base is stretched or bent, and is a device capable of maintaining the characteristics of the device even when external force is removed, and is a stretchable electronic device, a stretchable substrate It may be used interchangeably with a (stretchable) electronic device, a flexible (flexible) electronic device, and the like. A stretchable substrate according to an embodiment of the present invention is a wearable electronic device, an electronic skin, an electronic device for skin attachment, the Internet of Things, an electronic device for a vehicle, an intelligent robot, a stretchable display, a stretchable solar cell, a stretchable battery / It can be variously applied to energy harvesting and the like.

1 is a cross-sectional view of a stretchable substrate according to an embodiment of the present invention, FIG. 2 is a top view of the stretchable substrate according to an embodiment of the present invention, and FIG. 3 is another embodiment of the present invention It is a cross-sectional view of a stretchable substrate. 4 is a perspective view of a first stretchable base according to an embodiment of the present invention, and FIG. 5 is a perspective view of a second stretchable base according to an embodiment of the present invention.

1 to 2 , the stretchable substrate 100 includes a first stretchable base 110 , a second stretchable base 120 disposed on the first stretchable base 110 , The wiring 130 is disposed on the second stretchable base 120 .

The wiring 130 includes a first pad 132 and a second pad 134 , and a connection part 136 connecting the first pad 132 and the second pad 134 .

Here, the first stretchable base 110 and the second stretchable base 120 may be bent by an external force or stretched in at least one direction by an external force. That is, the first stretchable base 110 and the second stretchable base 120 may be stretchable bases, and in the present specification, the first stretchable base 110 and the second stretchable base 120 . ) may be mixed with a flexible base, a flexible base, a flexible base, a stretchable base, a stretchable base, an elastic base, and the like. The first stretchable base 110 and the second stretchable base 120 may be restored to their original state when the external force is removed. To this end, the first stretchable base 110 and the second stretchable base 120 may include a polymer resin having a predetermined elasticity. For example, the first stretchable base 110 and the second stretchable base 120 may include at least one of polyurethane (PU) and polydimethylsiloxane (PDMS). Accordingly, the first stretchable base 110 and the second stretchable base 120 may be elastically stretched according to an external force.

Meanwhile, the first pad 132 and the second pad 134 are disposed on the second stretchable base 120 , and the first pad 132 and the second pad 134 are the same as the connection part 136 . It may be made of a material or may be made of a material different from the connection part 136 but having conductivity. A semiconductor device is disposed on the first pad 132 and the second pad 134 and may be connected to the semiconductor device. Alternatively, the first pad 132 and the second pad 134 may be electrically connected to a component on the second stretchable base 120 or may be connected to an external power source. In this case, the first pad 132 and the second pad 134 may be bent or stretched together with the bending or stretching of the first stretchable base 110 and the second stretchable base 120 .

The first pad 132 , the second pad 134 , and the connection part 136 may include a polyimide (PI) layer and a metal layer disposed on the polyimide (PI) layer. The metal layer may include at least one of Au, Cu, Pt, and Ag. In this case, the polyimide (PI) layer may be disposed to contact the second stretchable base 120 . Accordingly, the adhesive force between the metal layer and the second stretchable base 120 may be increased.

Meanwhile, the connection part 136 may include a repeated curved pattern. For example, the repeated curved pattern may be a meandering pattern or the like that is meandering. According to this, the wiring 130 may be a stretchable wiring, and as shown in FIG. 2(b) , the first stretchable substrate 110 and the second stretchable substrate 120 are stretched The connection part 136 may also be stretched and contracted together.

Alternatively, the connection part 136 may be wound in a spiral shape between the first pad 132 and the second pad 134 . Here, the spiral shape is in a predetermined direction, for example, a direction parallel to the plane direction of the first stretchable base 110 and the second stretchable base 120 , that is, from the first pad 132 to the second pad ( It may refer to a three-dimensional shape extending while repeatedly rotating with a predetermined curvature in a direction toward the 134 , or in a direction from the second pad 134 to the first pad 132 . The spiral shape may be used interchangeably with a spiral shape, a helical shape, and the like. At this time, the diameter of the spiral shape is 30 μm to 1 mm, preferably 50 μm to 500 μm, more preferably 100 μm to 300 μm, and the spacing between the spiral spirals is 1 μm to 5 mm, preferably 100 μm to 3 mm. , more preferably 300 μm to 2 mm.

According to this, the wiring 130 can also be bent or stretched without restriction according to the bending or expansion and contraction of the first stretchable base 110 and the second stretchable base 120 , and the degree of integration of the wiring 130 is increased. Therefore, the overall size of the stretchable substrate 100 may be miniaturized. In particular, even when the wiring 130 is made of an inorganic material that does not have elasticity, it can be bent or stretched together with the first stretchable base 110 and the second stretchable base 120 due to the spiral shape. The material of 130 may not be restricted. In addition, even if the wiring 130 is also bent or stretched according to the bending or stretching of the first stretchable base 110 and the second stretchable base 120, the actual length of the wiring 130 does not increase, A change in resistance can be minimized, and a reliable stretchable substrate can be obtained.

Meanwhile, the stretchable substrate 100 according to an embodiment of the present invention may be applied to an application attached to the skin. When the stretchable substrate 100 is attached to the skin, the stretchable substrate 100 may hold moisture due to sweat discharged from the skin, and this may cause the user to feel a foreign body feeling and discomfort. Adhesion between the retractable substrate 100 and the skin may be reduced.

Accordingly, air permeability can be imparted by forming pores in the stretchable base of the stretchable substrate 100 , but when the stretchable substrate 100 is excessively stretched, stress is concentrated in the pores and the stretchable base is It can be torn easily, and the wiring is likely to be damaged.

Accordingly, in the embodiment of the present invention, the first stretchable base 110 and the second stretchable base 120 of the stretchable substrate 100 are intended to be heterogeneous.

According to an embodiment of the present invention, referring to FIG. 4 , the first stretchable base 110 may be a porous elastic base. Here, the elastic base may include at least one of polyurethane (PU) and polydimethylsiloxane (PDMS). And, the first stretchable base 110 has a porosity of 20 to 60%, preferably 25 to 55%, more preferably 30 to 50%, and an average diameter (d) of pores is 10 to 100 μm. can Here, the porosity may mean a percentage of the volume of the pores with respect to the total volume of the first stretchable base 110 . In general, the average particle diameter of sweat discharged from the skin may be 10 μm or less, and the average particle diameter of water droplets may be 100 μm or more. When the porosity and the average diameter (d) of the pores of the first stretchable base 110 satisfy the above numerical ranges, sweat discharged from the skin may be dispersed into the pores of the first stretchable base 110 and , since it is possible to prevent the penetration of water droplets from the outside, it is possible to minimize the user's feeling of foreign body and discomfort, and it is possible to maintain adhesion with the skin. In this case, the pores of the first stretchable base 110 may be formed by imprinting a polymer bead in the elastic base, curing it, and then melting the polymer bead. Alternatively, the pores of the first stretchable base 110 may be formed using the concept of a block copolymer. Alternatively, the first stretchable base 110 may be formed using a nanoimprinting technique. Alternatively, the first stretchable base 110 may be formed using a foaming technique.

Meanwhile, according to an embodiment of the present invention, referring to FIG. 5 , the second stretchable base 120 may be a strain-limiting base that is stretched within a predetermined range, and the second stretchable base The porosity of 120 may be smaller than the porosity of the first stretchable base 110 . Here, the predetermined range may be 20 to 30% of the width of the second stretchable base 120 . That is, the second stretchable base 120 may extend to 20 to 30% of the width of the second stretchable base 120 , but may not extend beyond that. For example, when the width of the second stretchable base 120 is 3 cm, when an external force is applied to both sides in a direction parallel to the width of the second stretchable base 120, the second stretchable base ( 120) is stretched to 3.6 to 3.9 cm, and may not be stretched beyond that.

According to this, sweat discharged from the skin is dispersed into the pores of the first stretchable base 110 having breathability to minimize the user's feeling of foreign body and discomfort, while the second stretchable base 120 is stretchable. Since the substrate 100 can be prevented from being excessively stretched, damage to the wiring 130 can be prevented.

In order to limit the elongation of the second stretchable base 120, the second stretchable base 120 is molded in the elastic base 122 and the elastic base 122 of FIG. 5(a) in FIG. 5(b). Alternatively, the elongation control structure 124 of FIG. 5(c) may be included. In this case, the elastic base 122 may include at least one of polyurethane (PU) and polydimethylsiloxane (PDMS). The elongation control structure 124 may include a fiber mat or a mesh film having a higher Young's modulus than the elastic base 122 . The diameter of the fibers constituting the fiber mat as shown in FIG. 5(b) may be 0.3 to 1 μm. The mesh film shown in FIG. 5( c ) may be formed using laser patterning or the like. In this case, at least one of the fiber mat and the mesh film may include at least one of polyimide and polyethylene terephthalate. As such, when the elongation control structure 124 having a relatively high Young's modulus is molded in the elastic base 122 having a relatively low Young's modulus, the elongation control structure of the second stretchable base 120 has a relatively high Young's modulus. (124) can be controlled.

Meanwhile, in FIGS. 1 to 2 , the second stretchable base 120 is disposed on the first stretchable base 110 , and the wiring 130 is disposed on the second stretchable base 120 . However, the stacking order of the first stretchable base 110 , the second stretchable base 120 , and the wiring 130 is not limited thereto. In an application in which the wiring 130 is in direct contact with the skin, as shown in FIG. 3 , a first stretchable base 110 is disposed on the wiring 130 , and the first stretchable base 110 is It may have a stacking order in which the second stretchable base 120 is disposed thereon.

6 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention, FIG. 7 is a cross-sectional view of a stretchable substrate according to another embodiment of the present invention, and FIG. 8 is another embodiment of the present invention. It is a cross-sectional view of the stretchable substrate according to the

6 to 8 , at least a portion of the first stretchable base 110 , the second stretchable base 120 , and the wiring 130 may be embedded in the resin 140 including silicon. . Here, the resin 140 including silicon may include PDMS. In this case, the thickness (T) of the resin 140 including silicon may be 1.5 to 2.5 times, preferably 1.7 to 2.3 times, more preferably 1.8 to 2.1 times the thickness (t) of the wiring 130 . For example, the thickness t of the wiring 130 may be about 100 μm, and the thickness of the resin T including silicon may be about 200 μm. Accordingly, it is possible to prevent the problem that the wiring 130 is cut or damaged even when the stretchable substrate 100 is repeatedly bent or stretched, and the wiring 130 can be protected from the outside. In addition, since the resin 140 including silicon has elasticity, it may be bent or stretched together with the bending or stretching of the stretchable substrate 100 .

At this time, the resin 140 including silicone is the same material as the elastic base of the first stretchable base 110 and the second stretchable base 120 , and may be integrally formed.

Meanwhile, referring to FIGS. 7 to 8 , the wiring 130 and the resin 140 including silicon may be formed in multiple layers. For example, a wire 130-1 and a resin 140-1 including silicon for molding the wire 130-1 are disposed on the second stretchable base 120, and the wire 130-2 and a resin for molding the wire 130-2 again are disposed on the second stretchable base 120. A resin 140 - 2 including silicon may be disposed. At this time, as shown in FIG. 8 , the wirings 130 - 1 and 130 - 2 arranged in different layers may be connected through the via 160 , and a chip may be disposed on the wiring 130 .

Accordingly, wiring of a complex structure is possible on the stretchable substrate 100 , and the stretchable substrate 100 is attached to the skin to perform a sensing function as well as a transmitter and the like. Accordingly, since a structure for processing and transmitting sensed information does not need to be attached to the user's skin, user convenience can be improved.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be done.

Claims (11)

a first stretchable base;
a second stretchable base disposed on the first stretchable base;
and a wiring disposed on at least one of the first stretchable base and the second stretchable base,
The porosity of the first stretchable base is greater than the porosity of the second stretchable base,
The second stretchable base is a stretchable substrate that is a stretch limiting base that is stretched within a predetermined range. According to claim 1,
The first stretchable base is a stretchable substrate that is a porous elastic base having a porosity of 20 to 60%. 3. The method of claim 2,
An average diameter of the pores of the first stretchable base is 10 to 100㎛ stretchable substrate. According to claim 1,
The predetermined range is 20 to 30% of the width of the second stretchable base. 5. The method of claim 4,
The second stretchable base is a stretchable substrate including an elastic base and an elongation control structure molded in the elastic base. 6. The method of claim 5,
The stretch control structure may include a fiber mat or a mesh film having a higher Young's modulus than the elastic base. 7. The method of claim 6,
A stretchable substrate having a diameter of 0.3 to 1 μm of fibers constituting the fiber mat. 7. The method of claim 6,
At least one of the fiber mat and the mesh film is a stretchable substrate comprising at least one of polyimide and polyethylene terephthalate. According to claim 1,
At least a portion of the first stretchable base, the second stretchable base, and the wiring is embedded in a resin containing silicon. According to claim 1,
The wiring is a stretchable substrate including a repeating curved pattern. According to claim 1,
wherein the wiring includes a polyimide layer and a metal layer disposed on the polyimide layer.

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