KR102680847B1 - Stretchable substrate and electronic device comprising same - Google Patents

Abstract

This specification relates to a stretchable substrate and an electronic device including the same.

Description

Stretchable substrate and electronic device comprising the same {STRETCHABLE SUBSTRATE AND ELECTRONIC DEVICE COMPRISING SAME}

This specification describes a stretchable substrate and an electronic device including the same.

Conventionally, display devices include an unbreakable display, a curved display, a bent display, a foldable display, and a rollable display. has been developed

The current commercialization stage is limited to the mobile field in the form of a curved display, and the mobile field using foldable displays is expected to emerge in earnest. In addition, the speed of development in the electronic field using pOLED is also remarkable.

In particular, in recent years, with the change in display paradigm, stretchable displays that go beyond the characteristics of rollable displays have been developed. Stretchable displays require the characteristics of being able to easily stretch and shrink regardless of direction. The development of elastic substrates with high elongation and resilience is essential.

In the case of a stretchable display device that includes an electronic device such as an organic light emitting device, the electronic device does not include flexibility, so a change in surface area due to stretching of the stretchable substrate has the problem of significantly reducing the durability of the electronic device.

It has been proposed that the application areas for flexible displays can be applied starting with touch screen panels, wearable displays using fiber, and displays for medical purposes.

According to the above-mentioned necessity, when forming an electronic device on a stretchable substrate, it is necessary to develop a stretchable substrate that can maintain the durability of the electronic device, has excellent adhesion between the electronic device and the stretchable substrate, and has excellent elasticity.

Japanese Patent Publication No. 2006-299283

This application seeks to provide a stretchable substrate and an electronic device including the same.

An exemplary embodiment of the present application includes a stretchable polymer film having a concave portion on at least one side; a non-stretchable pattern provided in the concave portion of the stretchable polymer film; and two or more spaced apart adhesive layer patterns provided on a surface opposite to the surface of each non-stretchable pattern in contact with the stretchable polymer film.

In another exemplary embodiment, a stretchable substrate according to the present application; and an electronic device provided on a region corresponding to the non-stretchable pattern of the stretchable substrate.

The stretchable substrate according to an exemplary embodiment of the present application is provided with a non-stretchable pattern in the concave portion of the stretchable polymer film, so that when an electronic device is later placed on the non-stretchable pattern of the stretchable substrate, the electronic device is The durability of the electronic device is significantly improved due to a small change in the surface area of the arranged non-stretchable pattern.

In addition, the stretchable substrate according to the present application includes two or more spaced apart adhesive layer patterns at corresponding positions on the non-stretchable pattern, and the adhesive layer is not provided in the form of a single layer, so the interface between the non-stretchable pattern and the stretchable polymer film Since no adhesive layer is provided, electronic devices can be stacked stably even when stretching and shrinking are repeated several times, preventing the problem of electronic devices being detached from the stretchable substrate during post-processing.

The stretchable substrate according to the present application is provided with two or more spaced apart adhesive layer patterns on the opposite side of the surface of each non-stretchable pattern in contact with the stretchable polymer film, and may be characterized by excellent adhesion to electronic devices in the future. In particular, by having a spaced-apart adhesive layer pattern, the adhesive layer pattern can be positioned more precisely on the non-stretchable pattern compared to having a single-layer adhesive layer, and as a result, the alignment of the adhesive layer pattern during the manufacturing process is difficult. It has features that make it simpler.

1 is a side view showing a stretchable substrate according to an exemplary embodiment of the present application.
Figure 2 is a side view showing a stretchable polymer film according to an exemplary embodiment of the present application.
Figure 3 is a top view showing a stretchable substrate according to an exemplary embodiment of the present application.
Figure 4 is a side view showing a stretchable substrate according to an exemplary embodiment of the present application.
Figure 5 is a diagram showing a scanning electron microscopy (SEM) image of the stretchable substrate of Comparative Example 2 of the present application.

Hereinafter, this specification will be described in more detail.

Embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

An exemplary embodiment of the present application includes a stretchable polymer film having a concave portion on at least one side; a non-stretchable pattern provided in the concave portion of the stretchable polymer film; and two or more spaced apart adhesive layer patterns provided on a surface opposite to the surface of each non-stretchable pattern in contact with the stretchable polymer film.

The stretchable substrate according to the present application is provided with two or more spaced apart adhesive layer patterns on the opposite side of the surface of each non-stretchable pattern in contact with the stretchable polymer film, and may be characterized by excellent adhesion to electronic devices in the future. In particular, by having a spaced-apart adhesive layer pattern, the adhesive layer pattern can be positioned more precisely on the non-stretchable pattern compared to having a single-layer adhesive layer, and as a result, the alignment of the adhesive layer pattern during the manufacturing process is difficult. It has features that make it simpler.

In addition, the stretchable substrate according to the present application includes two or more adhesive layer patterns at corresponding positions on each of the non-stretchable patterns, and the adhesive layer pattern is not provided at the interface between the non-stretchable pattern and the stretchable polymer film, so it can stretch and contract several times. Even when repeating, the stacking of electronic devices can be stably achieved, which has the feature of preventing the problem of electronic devices being detached from the stretchable substrate during post-processing.

In an exemplary embodiment of the present application, the stretchable polymer film has a concave portion on at least one side, and as can be seen in FIG. 2, it can be confirmed that the stretchable polymer film 1 has a concave portion 4 on one side. .

In an exemplary embodiment of the present application, the stretchable polymer film has a concave portion on at least one side, and at least one side means that the stretchable polymer film may have a concave portion on one side, and more than one side of the stretchable polymer film. This may mean that there may be a concave part.

In an exemplary embodiment of the present application, an elastic substrate is provided wherein when the absolute value of the difference between the depth of the concave portion and the height of the non-stretchable pattern is defined as M2, M2 is 0 μm or more and 10 μm or less.

In another embodiment, when the absolute value of the difference between the depth of the concave portion and the height of the non-stretchable pattern is defined as M2, M2 is 0 μm or more and 10 μm or less, preferably 0 μm or more and 8 μm or less. , more preferably 0 μm or more and 5 μm or less.

In an exemplary embodiment of the present application, the greater absolute value of the depth of the concave portion and the height of the non-stretchable pattern is defined as M1, and the absolute value of the difference between the depth of the concave portion and the height of the non-stretchable pattern is defined as M2. When doing so, the error range can be expressed as a value of M2/M1 x 100 (%), and the error range can have a value of 0.01% to 3%.

In an exemplary embodiment of the present application, the depth of the concave portion and the height of the non-stretchable pattern may correspond to each other, and the fact that the depth of the concave portion and the height of the non-stretchable pattern correspond to each other may include the same thing.

In the present application, “the same” may mean that the depth of the concave portion of the stretchable polymer film and the height of the adhesive layer are the same, and may also include a case where there is a step. In other words, the term “same” may include not only numerical equality but also cases where there is a step difference.

The step refers to the difference between the height of the non-stretchable pattern and the depth of the concave portion. In an exemplary embodiment of the present application, the step is the same as the definition of M2.

Figure 1 shows a side view of a stretchable substrate according to an exemplary embodiment of the present application. Specifically, the stretchable substrate includes a stretchable polymer film (1) having a concave portion, a non-stretchable pattern (2) provided in the concave portion, and two or more layers provided on the opposite side of the side of each non-stretchable pattern in contact with the stretchable polymer film. It can be confirmed that it has a stacked structure of spaced apart adhesive layer patterns 3.

That is, the stretchable substrate according to the present application has two or more adhesive layer patterns at positions corresponding to the non-stretchable pattern, and has the feature of making it easier to place the adhesive pattern on top of the non-stretchable pattern compared to the case of having one adhesive layer pattern, In addition, it has excellent adhesion to electronic devices, resulting in excellent durability of electronic devices in the future.

In an exemplary embodiment of the present application, the adhesive layer pattern provides a stretchable substrate including at least one selected from the group consisting of silicone-based adhesives, epoxy-based adhesives, cyanoacrylate-based adhesives, and acrylic-based adhesives.

In an exemplary embodiment of the present application, the silicone-based adhesive is Shinetsu KR-3700.

In an exemplary embodiment of the present application, the acrylic adhesive includes 3M Optical Clear Adhesive (OCA).

In an exemplary embodiment of the present application, the adhesive layer pattern may be a silicone-based adhesive layer.

In an exemplary embodiment of the present application, the adhesive layer pattern may be an acrylic adhesive layer.

In an exemplary embodiment of the present application, the silicone-based adhesive layer includes polyorganosiloxane and a curing catalyst.

In the case of the silicon-based adhesive layer, the surface is exposed at the top of the flexible substrate, and the components and content contained in the silicon-based adhesive layer in the flexible substrate can be confirmed by NMR (Nuclear magnetic resonance) analysis.

In an exemplary embodiment of the present application, the silicone-based adhesive layer can be formed by drying the silicone-based adhesive layer composition.

In an exemplary embodiment of the present application, the silicone-based adhesive layer can be formed by curing a silicone-based adhesive layer composition.

In an exemplary embodiment of the present application, the silicone-based adhesive layer composition includes polyorgano siloxane; curing catalyst; and a solvent.

In an exemplary embodiment of the present application, the solvent is not limited as long as it can dissolve the silicone-based adhesive layer composition. Specifically, an organic solvent may be used, and more specifically, toluene may be used.

In an exemplary embodiment of the present application, the polyorganosiloxane may be included in an amount of 40 to 70 parts by weight, preferably 45 to 60 parts by weight, and more preferably 45 to 55 parts by weight, based on 100 parts by weight of the silicone-based adhesive layer composition. there is.

In an exemplary embodiment of the present application, the curing catalyst may be included in an amount of 0.1 to 2 parts by weight, preferably 0.2 to 1 part by weight, and more preferably 0.3 to 0.8 parts by weight, based on 100 parts by weight of the silicone-based adhesive layer composition.

In an exemplary embodiment of the present application, the solvent may be included in an amount of 40 to 70 parts by weight, preferably 45 to 60 parts by weight, and more preferably 45 to 55 parts by weight, based on 100 parts by weight of the silicone-based adhesive layer composition.

Since the stretchable substrate according to the present application has a silicone-based adhesive layer, the adhesive force with the non-stretchable pattern can be maintained even after repeated stretching and contraction, and the silicone-based adhesive layer also has excellent elongation, making it excellent for application to stretchable substrates. .

In an exemplary embodiment of the present application, the non-stretchable pattern has a structure of two or more islands spaced apart from each other on the stretchable polymer film, the line width of the non-stretchable pattern is D1, and two adjacent islands are formed on the stretchable polymer film. The distance between the stretchable patterns is D2, and D1 and D2 satisfy the following Equations 1 and 2.

[Equation 1]

30μm ≤ D1 ≤ 1000μm

[Equation 2]

D1/D2 ≤ 4

That the non-stretchable pattern has two or more island structures spaced apart in the stretchable polymer film includes both the non-stretchable pattern having a regularly spaced island structure or the non-stretchable pattern having an irregularly spaced island structure. can do. That is, the value of D2 may be the same among all non-stretch patterns, or may also be different.

In the present application, adjacent means touching next to or closest to the target configuration. Specifically, adjacent non-stretchable patterns mean based on one specific non-stretchable pattern. This means that the distance between the center of a specific non-elastic pattern and the center of a neighboring non-elastic pattern is closest.

Figure 3 shows a top view of a stretchable substrate according to an exemplary embodiment of the present application. Specifically, the line width (100) of the non-stretchable pattern and the distance (200) between adjacent non-stretchable patterns can be confirmed.

In an exemplary embodiment of the present application, the non-stretchable pattern may have a polygonal cross-section in the line width direction of the non-stretchable pattern.

In an exemplary embodiment of the present application, the non-stretchable pattern may have a cross-section in the line width direction of the non-stretchable pattern selected from the group consisting of a circle, triangle, square, pentagon, and hexagon.

In another embodiment, the non-stretchable pattern may have a square cross-section in the line width direction of the non-stretchable pattern.

In an exemplary embodiment of the present application, Equation 1 may be 30μm ≤ D1 ≤ 1000μm, preferably 30μm ≤ D1 ≤ 500μm, and more preferably 30μm ≤ D1 ≤ 100μm.

In an exemplary embodiment of the present application, Equation 2 may be D1/D2 ≤ 4, preferably D1/D2 ≤ 2, and more preferably D1/D2 ≤ 1.

In another exemplary embodiment, Equation 2 may be D1/D2 ≥ 0.1, preferably D1/D2 ≥ 0.5, and more preferably D1/D2 ≥ 0.8.

In an exemplary embodiment of the present application, D2 may be 30 μm ≤ D2 ≤ 500 μm, preferably 55 μm ≤ D2 ≤ 300 μm, and more preferably 65 μm ≤ D2 ≤ 100 μm.

As the stretchable substrate according to the present application satisfies the range of Equation 1 and Equation 2 above, when the stretchable substrate of the present application is stretched, no separation occurs between the non-stretchable pattern and the stretchable polymer film, and the stretchability satisfies the elongation rate and hardness. It has the ability to manufacture substrates.

In one embodiment of the present application, the adhesive layer is in contact with one side of the stretchable polymer film, and is provided on the stretchable polymer film to protrude to the outside.

In an exemplary embodiment of the present application, the Young's Modulus of the stretchable polymer film is G1, the Young's Modulus of the non-stretchable pattern is G2, and G1 and G2 satisfy Equations 3 to 5 below. Provides a stretchable substrate that does this.

[Equation 3]

G1 ≤ 2 MPa

[Equation 4]

G2 ≥ 1000 MPa

[Equation 5]

G2/G1 ≥ 500

The Young's modulus of the stretchable polymer film and the non-stretchable pattern can be measured using Zwick/Roell's Z010 UTM equipment. Specifically, the stretchable polymer film and the non-stretchable material in film form can be measured at 25±2°C and 50±5%. Under RH (relative humidity), fix both ends in the longitudinal direction so that the width is 25mm and the length is 165mm, then stretch on both sides in the longitudinal direction at a speed of 100mm/min, and Young's modulus can be obtained through Stress/Strain measurement.

In an exemplary embodiment of the present application, Equation 3 may be G1 ≤ 2 MPa, preferably G1 ≤ 1.7 MPa, and more preferably G1 ≤ 1.5 MPa.

In another exemplary embodiment, Equation 3 may be G1 ≥ 0.01 MPa, preferably G1 ≥ 0.1 MPa, and more preferably G1 ≥ 0.3 MPa.

In an exemplary embodiment of the present application, Equation 4 is G2 ≥ 1000 MPa, preferably G2 ≥ 2000 MPa, more preferably G2 ≥ 4000 MPa It can be.

In another embodiment, Equation 4 is G2 ≤ 10000 MPa, preferably G2 ≤ 9000 MPa, more preferably G2 ≤ 8000 MPa. It can be.

In an exemplary embodiment of the present application, Equation 3 may be 0.01 MPa ≤ G1 ≤ 2 MPa, preferably 0.1 MPa ≤ G1 ≤ 1.7 MPa, and more preferably 0.3 MPa ≤ G1 ≤ 1.5 MPa.

In an exemplary embodiment of the present application, Equation 4 may be 1000 MPa ≤ G2 ≤ 10000 MPa, preferably 2000 MPa ≤ G2 ≤ 8000 MPa, and more preferably 4000 MPa ≤ G2 ≤ 8000 MPa.

As the stretchable substrate satisfies the range of Equation 3 and Equation 4, when the stretchable substrate is stretched along one axis, no separation occurs at the interface between the non-stretchable pattern and the stretchable polymer film, thereby improving the durability of the electronic device in the future. It is possible to have these excellent characteristics.

In an exemplary embodiment of the present application, Equation 5 satisfies G2/G1 ≥ 500, preferably G2/G1 ≥ 1000, and more preferably G2/G1 ≥ 3000.

In another exemplary embodiment, Equation 5 satisfies G2/G1 ≤ 60000, preferably G2/G1 ≤ 30000, and more preferably G2/G1 ≤ 20000.

In an exemplary embodiment of the present application, Equation 5 satisfies 500 ≤ G2/G1 ≤ 60000, preferably 2000 ≤ G2/G1 ≤ 30000, and more preferably 3000 ≤ G2/G1 ≤ 20000.

As the ratio of the elastic polymer film and the non-stretchable pattern Young's modulus satisfies the above range as shown in Equation 5 above, the stretchable substrate has excellent elongation and durability.

In an exemplary embodiment of the present application, the non-stretchable pattern has a line width of A1, the adhesive layer pattern has a line width of A2, and A1 and A2 satisfy Equation 6 below.

[Equation 6]

0.005 < A2/A1 < 0.5

In an exemplary embodiment of the present application, the line width (A1) of the non-stretchable pattern has the same meaning as D1.

In an exemplary embodiment of the present application, the line width (A2) of the adhesive layer pattern is 5 μm ≤ A2 ≤ 500 μm, preferably 5 μm ≤ A2 ≤ 100 μm, more preferably 10 μm ≤ A2 ≤ 50 μm. have

When the line width (A1) of the non-stretchable pattern and the line width (A2) of the adhesive layer pattern satisfy the range of Equation 6, the adhesive layer pattern has particularly excellent transfer characteristics.

Figure 3 shows a top view of a stretchable substrate according to an exemplary embodiment of the present application. Specifically, the relationship between the line width (A1, 100) of the non-stretchable pattern and the line width (A2, 300) of the adhesive layer pattern can be confirmed.

In an exemplary embodiment of the present application, Equation 6 may be 0.005 < A2/A1 < 0.5, preferably 0.005 < A2/A1 < 0.3, and more preferably 0.01 < A2/A1 < 0.1.

In an exemplary embodiment of the present application, a stretchable substrate is provided wherein the height of the adhesive layer pattern is 1 μm or more and 100 μm or less.

In another embodiment, the height of the adhesive layer pattern may be 5 μm or more and 80 μm or less, preferably 8 μm or more and 50 μm or less, and more preferably 10 μm or more and 30 μm or less.

As the height of the adhesive layer pattern satisfies the above range, adhesion to the non-stretchable pattern is excellent, so that the adhesive layer does not separate from the stretchable substrate even after repeated stretching and shrinking several times, and when electronic devices are stacked later. It has excellent adhesive properties.

Figure 4 shows a side view of a stretchable substrate according to an exemplary embodiment of the present application, and in detail, the height 500 of the adhesive layer pattern can be confirmed.

In an exemplary embodiment of the present application, the height of the non-stretchable pattern may be 5 μm or more and 100 μm or less.

The height of the non-stretchable pattern refers to the height perpendicular to the line width direction of the non-stretchable pattern. Specifically, the height 300 of the non-stretchable pattern can be confirmed in Figure 3.

In another embodiment, the height of the non-stretchable pattern may be 5 μm or more and 100 μm or less, preferably 10 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

If the height of the non-stretchable pattern satisfies the above range, no deformation of the electronic device occurs during later stacking of the electronic device, and if the height is outside the above range, a gap occurs between the non-stretchable pattern and the stretchable polymer film. The durability of electronic devices becomes poor.

In an exemplary embodiment of the present application, the total area of the surface opposite to the surface of the one non-stretchable pattern in contact with the stretchable polymer film is B1, and the two or more adhesive layer patterns formed on the one non-stretchable pattern have the ratio of the one. The total area of the surface in contact with the elastic pattern is B2, and B1 and B2 satisfy Equation 7 below.

[Equation 7]

0.2 < B2/B1 < 0.9

The area can be confirmed in FIG. 3, where B1 refers to the total area of one non-stretchable pattern in FIG. 3 (shown as a rectangular area in FIG. 3), and B2 refers to several layers stacked on one non-stretchable pattern (FIG. 3 This means the total area of the adhesive layer patterns (example is 9).

The stretchable substrate according to the present application may be provided with the adhesive layer pattern on the non-stretchable pattern, and the number and spacing of the adhesive layer patterns may be provided at a constant level, but the line width for each position of the screen mask used to form the adhesive layer pattern Depending on the difference and dry physical properties of the adhesive layer composition, some differences in line width of the adhesive layer pattern may occur. That is, the stretchable substrate according to the present application is not limited thereto even if the number and spacing of the adhesive layer patterns are different during the formation process of the adhesive layer pattern, as long as it is within the range of Equation 6 and Equation 7.

In an exemplary embodiment of the present application, Equation 7 may be 0.2 < B2/B1 < 0.9, preferably 0.3 < B2/B1 < 0.9, and more preferably 0.5 < B2/B1 < 0.8.

In an exemplary embodiment of the present application, as the stretchable substrate satisfies the range of Equation 7 above, in manufacturing the stretchable substrate, when B1 and B2 have the same value (an adhesive layer in the same area is formed on the top of the non-stretchable pattern) The transfer process of the adhesive layer pattern becomes more convenient compared to the case of the adhesive layer pattern, and the adhesive layer pattern is not formed at the boundary between the non-stretchable pattern and the stretchable polymer film, so even when stretching the stretchable substrate, stretching of the adhesive layer pattern can be minimized. Electronic devices to be stacked in the future have particularly excellent durability.

In an exemplary embodiment of the present application, a stretchable substrate is provided wherein the number of adhesive layer patterns provided on the surface opposite to the surface of each non-stretchable pattern in contact with the stretchable polymer film is 2 or more and 36,000 or less.

In another embodiment, the number of adhesive layer patterns provided on the opposite side of the surface of each non-stretchable pattern in contact with the stretchable polymer film is 2 to 10,000, 4 to 5,000, preferably 6 to 1,000. It may be below.

In an exemplary embodiment of the present application, the number of the adhesive layer patterns is determined according to the size of the non-stretchable pattern, and is not limited to the above range. However, as the adhesive layer pattern in a spaced apart form is within the above range, the number of the adhesive layer patterns is determined in accordance with the size of the non-stretchable pattern. Compared to having an adhesive layer of

In an exemplary embodiment of the present application, the non-stretchable pattern can be used without particular limitation as long as it satisfies the Young's modulus of Equation 4, and a photocurable polymer material can be used, specifically a dry film resist for forming an electronic circuit board. , a photosensitive resin composition for a column spacer, and a photosensitive resin composition for forming an organic insulating pattern.

In an exemplary embodiment of the present application, a stretchable substrate made of polydimethylsiloxane (PDMS) having an elongation at break of 100% or more is provided.

In another embodiment, the elongation at break of the stretchable polymer film may be 100% or more, preferably 110% or more, and more preferably 130% or more.

In another exemplary embodiment, the elongation at break of the stretchable polymer film may be 180% or less, preferably 170% or less.

The breaking elongation rate of the stretchable polymer film means (L2-L1)/L1*100(%) when the initial length of the stretchable polymer film is L1 and the length at which breakage occurs by stretching is L2.

As the elongation at break of the stretchable polymer film satisfies the above range, the elongation of the stretchable substrate having a structure in which a non-stretchable pattern is embedded in the future has the characteristic of satisfying a specific range, and the stretchable polymer is used in the manufacturing process of the stretchable substrate. As the elongation of the film falls within the above range, it has characteristics that make it easy to handle.

In an exemplary embodiment of the present application, the stretchable polymer film can be used without particular limitation as long as it satisfies the Young's modulus of Equation 1, and polydimethylsiloxane polymer materials can be used, specifically condensation polymerization type polydimethylsiloxane, It may be selected from the group consisting of addition polymerization type polydimethylsiloxane and radical polymerization type polydimethylsiloxane.

In an exemplary embodiment of the present application, the stretchable polymer film may be polydimethylsiloxane.

In an exemplary embodiment of the present application, the adhesive strength after bonding the opposite side of the surface of the adhesive layer pattern in contact with the non-stretchable pattern to a polyimide film (PI, Polyimide) and leaving it for 1 hour at 23°C and 50 RH% is It can be more than 500 gf/inch.

In another embodiment, after bonding the opposite side of the surface of the adhesive layer pattern in contact with the non-stretchable pattern to a polyimide film (PI, Polyimide) and leaving it for 1 hour at 23°C and 50 RH%, the adhesive force is 500. It may be more than gf/inch, preferably more than 600 gf/inch, more preferably more than 700 gf/inch, and may be less than 2000 gf/inch, preferably less than 1500 gf/inch.

After bonding the opposite side of the surface of the adhesive layer pattern in contact with the non-stretchable pattern to a polyimide film (PI, Polyimide), the adhesive strength after being left for 1 hour at 23°C and 50 RH% satisfies the above conditions and ranges, so that it can be used later. When electronic devices are placed on the adhesive layer, stacking of the electronic devices can be performed stably, preventing problems of electronic devices being detached from the stretchable substrate during post-processing.

In an exemplary embodiment of the present application, an elastic substrate having an adhesive force of 500 gf/inch or more after bonding the surface of the adhesive layer pattern in contact with the non-stretchable pattern and leaving it for 1 hour at 23°C and 50 RH% is provided.

In another embodiment, after bonding the surface of the adhesive layer pattern in contact with the non-stretchable pattern, the adhesive strength after being left for 1 hour at 23°C and 50 RH% is 500 gf/inch or more, preferably 600 gf/inch or more, and further. Preferably it may be 700gf/inch or more.

In another embodiment, after bonding the surface of the adhesive layer pattern in contact with the non-stretchable pattern and leaving it for 1 hour at 23°C and 50 RH%, the adhesive strength is 2000 gf/inch or less, preferably 1500 gf/inch or less, and further. Preferably, it may be 1300gf/inch or less.

As the adhesive strength of the surface where the non-stretchable pattern and the adhesive layer pattern are in contact satisfies the above range, in the manufacturing process of the stretchable substrate herein, the adhesive layer pattern can be selectively laminated on the non-stretchable pattern, In addition, even if the stretchable substrate is repeatedly stretched and recovered several times, it has a specific adhesive strength and is not easily detached.

In the present application, the adhesive force is obtained by forming the adhesive layer pattern on a glass substrate to a thickness of 20㎛ and then laminating a non-stretchable pattern or polyimide film on one side of the adhesive layer pattern of the glass substrate provided with the adhesive layer pattern. After leaving it at 23°C and 50 RH% for 1 hour, the adhesive force can be measured by peeling the non-stretchable pattern or polyimide film from the adhesive layer at a 90° angle. (Texture Analyzer from Stable Micro Systems)

In an exemplary embodiment of the present application, the thickness of the stretchable polymer film may be 100 μm or more and 1000 μm or less.

In another embodiment, the thickness of the stretchable polymer film may be 100 μm or more and 1000 μm or less, preferably 100 μm or more and 700 μm or less, and more preferably 200 μm or more and 500 μm or less.

As the stretchable polymer film satisfies the above thickness range, the elongation rate of the stretchable substrate of the present application is excellent, and by having the above thickness range, the non-stretchable pattern and the stretchable polymer film have the characteristic of not being fractured in response to high elongation force. do.

Figure 3 shows a side view of the stretchable substrate herein, and the thickness 400 of the stretchable polymer film can be confirmed.

In an exemplary embodiment of the present application, the elongation rate of the stretchable substrate may be 20% or more.

In another embodiment, the elongation rate of the stretchable substrate may be 20% or more, preferably 35% or more, more preferably 50% or more, and may satisfy the range of 150% or less, preferably 130% or less. there is.

The elongation rate of the stretchable substrate refers to the maximum elongation rate at which no separation occurs between the stretchable polymer film and the non-stretchable pattern, and the separation between the stretchable polymer film and the non-stretchable pattern means that lifting has occurred. do. Specifically, if there is no separation, it means that the air layer is not visible and the adhesion between the stretchable substrate and the non-stretchable pattern is well done, and if there is separation, it means that a space has been created.

That is, the elongation rate of the stretchable substrate in the present application refers to the maximum elongation rate at which the separation does not occur depending on the line width of the non-stretchable pattern provided in the concave portion of the stretchable polymer film and the distance between adjacent non-stretchable patterns. This may mean the maximum elongation rate at which the separation does not occur.

The elongation rate of the stretchable substrate was measured by stretching a 2.5cm * 5cm stretchable substrate to the left and right in the direction of the long axis, and measuring the elongation rate at the point where separation occurs at the boundary between the non-stretchable pattern and the stretchable polymer film.

Ultimately, in the case of the stretchable substrate, it is composed of a stretchable polymer film in which a non-stretchable pattern is embedded, and even when the elongation rate of the stretchable substrate is within the above range, a stretchable substrate that does not cause separation between the non-stretchable pattern and the stretchable polymer film is provided. It has features that can be manufactured.

In an exemplary embodiment of the present application, a stretchable substrate is provided in which the deformation of the non-stretchable pattern is 3% or less when the stretchable substrate is stretched by 20%.

In another embodiment, when the stretchable substrate is stretched by 20%, the deformation of the non-stretchable pattern may be 3% or less, preferably 2% or less, and more preferably 1% or less.

In another embodiment, when the stretchable substrate is stretched, the deformation of the non-stretchable pattern may be 0.5% or more.

The fact that the stretchable substrate is stretched by 20% means that it is stretched by 20% based on the initial state of the stretchable substrate.

The deformation of the non-stretchable pattern can be confirmed through an optical microscope (OM) when the stretchable substrate is stretched. That is, the deformation of the non-stretchable pattern can be measured by measuring the initial size of the non-stretchable pattern before stretching the stretchable substrate through a microscope (OM) and then calculating the ratio of the size after stretching.

As the deformation of the non-stretchable pattern falls within the above range, the device can be stably supported when deposited on the adhesive layer pattern in the future, and thus durability is increased.

In an exemplary embodiment of the present application, a stretchable substrate according to the present application; and an electronic device provided on a region corresponding to the one non-stretchable pattern of the stretchable substrate.

In FIG. 2, the area corresponding to one non-stretchable pattern means that electronic devices are stacked on top of one non-stretchable pattern. In this case, electronic devices are stacked on top of the non-stretchable pattern through two or more spaced apart adhesive layers. This means that the elements are stacked.

In an exemplary embodiment of the present application, the electronic device may be a display device, a touch panel, or a semiconductor panel.

In one embodiment of the present application, the electronic device provides an electronic device selected from the group consisting of an organic photoelectric device, an organic transistor, an organic solar cell, a micro LED device, and an organic light-emitting device.

When the electronic device according to the present application is used in a display device, it may include a display having elasticity, and as the electronic device is formed on the adhesive layer pattern of the stretchable substrate, the electronic device itself is maintained even after repeated stretching and wrapping. External force applied to the display device can be minimized, thereby providing a display device with excellent elongation and durability.

In particular, as the stretchable substrate according to the present application includes an adhesive layer pattern with a specific adhesive force range, it has the feature of being able to stably place electronic devices on the stretchable substrate even after repeated stretching and reversal.

A stretchable substrate according to an exemplary embodiment of the present application includes forming a stretchable substrate with a non-stretchable pattern embedded therein; and transferring an adhesive layer pattern onto the elastic substrate.

Specifically, forming the stretchable substrate with the non-stretchable pattern embedded therein includes preparing copper foil; Laminating a protective film on one side of copper foil; forming a non-stretchable pattern on the opposite side of the copper foil to which the protective film is laminated; Applying a stretchable polymer film on the copper foil on which the non-stretch pattern is formed; and removing the protective film and copper foil.

In addition, transferring the adhesive layer pattern onto the stretchable substrate includes preparing a substrate; forming an adhesive layer pattern on one side of the substrate; A stretchable substrate with an adhesive layer pattern according to the present application can be manufactured through the step of laminating the substrate on which the adhesive layer pattern is formed on the surface of the non-stretchable pattern of the stretchable substrate.

That is, in the stretchable substrate according to the present application, the adhesive layer pattern is selectively transferred onto the top of a non-stretchable pattern with high surface energy, which is more convenient in the process than placing the adhesive layer pattern at a position corresponding to the top of the existing non-stretchable pattern. It has characteristics.

In an exemplary embodiment of the present application, the step of forming the non-stretchable pattern may be formed using a photolithography process.

In an exemplary embodiment of the present application, the protective film and the copper foil may be removed after applying the stretchable polymer film.

In an exemplary embodiment of the present application, the copper foil may be removed using an etchant, and the etchant may be an iron chloride-based copper etchant.

In an exemplary embodiment of the present application, forming an adhesive layer pattern on one side of the substrate includes forming a mask pattern on one side of the substrate through a photography process; forming an adhesive layer on top of the substrate on which the mask pattern is formed; and removing the mask pattern.

Below, the present specification will be described in more detail through examples. However, the following examples are only for illustrating the present specification and are not intended to limit the present specification.

< Manufacturing example >

< Example 1>

1. Preparation of adhesive layer pattern film

Polydimethylsiloxane (Shin-Etsu KE-441K-T) is applied to a thickness of 200㎛ on top of the 250㎛ PET film and cured at room temperature for 72 hours. On top of the laminate, a screen mask having an average diameter of openings of 50 ㎛, a distance between patterns of 50 ㎛, and a thickness of 50 ㎛, and a silicone-based adhesive layer composition (100 parts by weight of Shin-Etsu KR-3700 and Shin-Etsu CAT-PL) -50T (0.5 parts by weight) was used to form an adhesive layer pattern with an average diameter of 55㎛, a distance between patterns of 45㎛, and a height of 40㎛.

2. non-elastic Manufacturing of stretchable substrates with embedded patterns

Prepare 10㎛ thick copper foil with a protective film laminated on one side. After laminating a 25㎛ thick DFR (Dry Film Resist, Hitachi Chemical) as a photocurable polymer material on top of the copper foil, a square ratio with a non-stretchable pattern line width of 500㎛ and a distance between non-stretchable patterns of 500㎛ was obtained through a photo process. Forms an elastic pattern. KE-441K-T (Shinetsu) as a polydimethylsiloxane material was applied to a thickness of 300㎛ on the top of the laminate equipped with the non-stretchable pattern, cured at room temperature for 72 hours, and then heat treated at 100°C for an additional hour.

After removing the protective film from the laminate provided with the polydimethylsiloxane polymer layer, the exposed copper foil was removed using a ferric chloride-based copper etchant to produce a stretchable polymer film with an embedded non-stretchable pattern.

3. Manufacture of final stretchable substrate through transfer of adhesive layer pattern

The exposed surface of the non-stretchable pattern of the stretchable substrate in which the non-stretchable pattern was embedded was positioned to face the adhesive layer pattern-equipped surface of the adhesive layer pattern film, and then roll-laminated at a speed of 1.3 mpm (meter per minute). After completion of lamination, the adhesive layer pattern film was removed from the stretchable substrate in which the non-stretchable pattern was embedded, and the adhesive layer pattern was selectively transferred onto the non-stretchable pattern.

< Example 2>

In Example 1, instead of the silicone-based adhesive layer composition (100 parts by weight of Shin-Etsu KR-3700 and 0.5 parts by weight of Shin-Etsu CAT-PL-50T), an acrylic adhesive layer composition (3M pLOCA EAS-2290) was used as the adhesive layer composition. ), a stretchable substrate was manufactured in the same manner as in Example 1 except that ) was applied.

< Example 3>

In Example 1, a stretchable substrate was manufactured in the same manner as in Example 1, except that the average diameter of the adhesive layer pattern was 30㎛ and the distance between patterns was 70㎛.

< Comparative example 1>

Prepare 10㎛ thick copper foil with a protective film laminated on one side. After laminating a 25㎛ thick DFR (Dry Film Resist, Hitachi Chemical) as a photocurable polymer material on top of the copper foil, a square ratio with a non-stretchable pattern line width of 500㎛ and a distance between non-stretchable patterns of 500㎛ was obtained through a photo process. Forms an elastic pattern. KE-441K-T (Shinetsu) as a polydimethylsiloxane material was applied to a thickness of 300㎛ on the top of the laminate equipped with the non-stretchable pattern, cured at room temperature for 72 hours, and then heat treated at 100°C for an additional hour.

After removing the protective film from the laminate provided with the polydimethylsiloxane polymer layer, the exposed copper foil was removed using a ferric chloride-based copper etchant to produce a stretchable polymer film with an embedded non-stretchable pattern.

A silicone-based adhesive layer (100 parts by weight of Shin-Etsu KR-3700 and 0.5 parts by weight of Shin-Etsu CAT-PL-50T) was provided on the entire upper surface of the stretchable substrate with the non-stretchable pattern embedded therein, thereby manufacturing a stretchable substrate.

< Comparative example 2>

In Example 1, a stretchable substrate was manufactured in the same manner as Example 1, except that the average diameter of the adhesive layer pattern was 500 ㎛ and the distance between patterns was 500 ㎛.

Table 1 below shows the composition of the non-stretchable pattern and the adhesive layer pattern and the adhesion and durability according to physical properties for the stretchable substrates of Examples 1 to 3, Comparative Examples 1, and Comparative Example 2.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative example 2 non-elastic Pattern line width/ Between patterns distance 500㎛/500㎛ 500㎛/500㎛ 500㎛/500㎛ 500㎛/500㎛ 500㎛/500㎛ Adhesive layer pattern line width/distance between patterns 55㎛/45㎛ 55㎛/45㎛ 30㎛/70㎛ Introduction of front adhesive layer 500㎛/500㎛ Adhesive layer composition Silicone-based adhesive layer Acrylic adhesive layer Silicone-based adhesive layer Silicone-based adhesive layer Silicone-based adhesive layer Adhesive layer pattern area ratio (B2/B1) 0.3 0.3 0.1 One Not measurable (1:1 response not possible due to dimensional error during transfer process) Adhesive layer pattern - non-stretchable pattern inter-adhesion 600gf/inch 550gf/inch 230gf/inch 980 gf/inch 530gf/inch Adhesive layer pattern - polyimide between films adhesion 580gf/inch 510gf/inch 180gf/inch 900 gf/inch 500gf/inch Durability observed at 20% tension No border separation No border separation No border separation Observation of damage to the upper adhesive layer at the border of the non-stretchable pattern Observation of damage to the upper adhesive layer at the border of the non-stretchable pattern

In Table 1, the durability observation at 20% tension is obtained after repeating 20% tension and restoration of the stretchable substrates of Examples 1 to 3 and Comparative Examples 1 and 2 10 times, and then measuring the scan electron density in the restored state of the stretchable substrate. When observed with a microscope (SEM, Scanning Electron Microscopy) image, it was confirmed whether separation occurred at the boundary.

As can be seen in Table 1 above, the stretchable substrate according to the present application is provided with a non-stretchable pattern in the concave portion of the stretchable polymer film, so when an electrical device is placed on the stretchable substrate in the future, the surface area change due to stretching is small and the electrical device is used. It was confirmed that the durability of the device was significantly improved.

In Table 1, in Examples 1 and 2, the adhesive layer pattern line width/distance between adhesive layer patterns satisfies 55㎛/45㎛, respectively. Not only is the durability of the adhesive layer excellent by having two or more adhesive layers spaced apart, It was confirmed that the adhesion between the adhesive layer pattern and the electronic devices to be laminated later was also particularly excellent.

The stretchable substrate according to the present application is provided with two or more spaced apart adhesive layer patterns on the opposite side of the side in contact with the stretchable polymer film of each non-stretch pattern, so that it can have excellent adhesion to electronic devices in the future, and can be separated By having an adhesive layer pattern in the form of a single layer, the adhesive layer pattern can be positioned more precisely on the non-stretchable pattern compared to having a single-layer adhesive layer (Comparative Example 1), and thus the adhesive layer pattern can be aligned during the manufacturing process. ) was confirmed to have the feature of being simple.

In particular, in the case of Comparative Example 1, which has a single-layer adhesive layer, the adhesive strength between the adhesive layer and the electronic device to be laminated later can be maintained within a certain range, but in the case where the adhesive layer is stretched several times due to the single-layer adhesive layer, It was confirmed that damage to the adhesive layer occurred, and accordingly, the durability of the electronic device was confirmed to be reduced.

In the case of Comparative Example 2, the adhesive layer is laminated in a pattern on top of the non-stretchable pattern, but when the adhesive layer pattern and the non-stretchable pattern correspond 1:1 rather than in the form of two or more spaced apart patterns (non-stretchable pattern line width and adhesive layer pattern line width) The adhesive strength between the adhesive layer and the electronic device to be laminated later can be maintained within a certain range, but it was confirmed that damage to the adhesive layer occurs when stretching and contracting is repeated several times due to the adhesive layer having a 1:1 correspondence. Accordingly, it was confirmed that the durability of the electronic device decreased.

Figure 5 is a diagram showing a scanning electron microscopy (SEM) image of the stretchable substrate of Comparative Example 2 after being stretched by 20%. It was confirmed whether the upper adhesive layer at the border of the non-stretchable pattern was deformed, and it was confirmed that tears and steps occurred in the adhesive layer pattern at the upper part of the non-stretchable pattern border.

1: Stretchable polymer film
2: Non-stretch pattern
3: Adhesive layer pattern
4: recess
100: Line width of non-stretchable pattern
200: Distance between adjacent inelastic patterns
300: Line width of adhesive layer pattern
400: Thickness of stretchable polymer film
500: Height of adhesive layer pattern

Claims (16)

A stretchable polymer film having a concave portion on at least one side;
a non-stretchable pattern provided in the concave portion of the stretchable polymer film; and
two or more spaced apart adhesive layer patterns provided on a surface opposite to a surface of each non-stretchable pattern in contact with the stretchable polymer film;
Includes,
The total area of the surface opposite to the surface of the one non-stretchable pattern in contact with the stretchable polymer film is B1, and the total area of the surface of the two or more adhesive layer patterns formed on the one non-stretchable pattern in contact with the one non-stretchable pattern is B1. It is B2,
The stretchable substrate B1 and B2 satisfy the following equation 7:
[Equation 7]
0.2 < B2/B1 < 0.9 In claim 1,
When the absolute value of the difference between the depth of the concave portion and the height of the non-stretchable pattern is defined as M2, M2 is 0 μm or more and 10 μm or less. In claim 1,
A stretchable substrate wherein the adhesive layer pattern includes one or more selected from the group consisting of silicone-based adhesives, epoxy-based adhesives, cyanoacrylate-based adhesives, and acrylic-based adhesives. In claim 1,
The non-stretchable pattern has a structure of two or more islands spaced apart from the stretchable polymer film,
The line width of the non-stretchable pattern is D1,
The distance between two adjacent non-stretchable patterns on the stretchable polymer film is D2,
A stretchable substrate wherein D1 and D2 satisfy the following Equations 1 and 2:
[Equation 1]
30μm ≤ D1 ≤ 1000μm
[Equation 2]
D1/D2 ≤ 4 In claim 1,
Young's Modulus of the stretchable polymer film is G1,
Young's Modulus of the non-stretchable pattern is G2,
A stretchable substrate wherein G1 and G2 satisfy the following Equations 3 to 5:
[Equation 3]
G1 ≤ 2 MPa
[Equation 4]
G2 ≥ 1000 MPa
[Equation 5]
G2/G1 ≥ 500 In claim 1,
The line width of the non-stretchable pattern is A1, the line width of the adhesive layer pattern is A2,
A stretchable substrate wherein A1 and A2 satisfy the following equation 6:
[Equation 6]
0.005 < A2/A1 < 0.5 delete In claim 1,
A stretchable substrate, wherein the number of adhesive layer patterns provided on the surface opposite to the surface of each non-stretchable pattern in contact with the stretchable polymer film is 2 or more and 36,000 or less. In claim 1,
A stretchable substrate made of polydimethylsiloxane (PDMS) having an elongation at break of 100% or more. In claim 1,
An elastic substrate having an adhesive force of 500 gf/inch or more after bonding the opposite side of the surface of the adhesive layer pattern in contact with the non-stretchable pattern to a polyimide film (PI, Polyimide) and leaving it for 1 hour at 23°C and 50 RH%. . In claim 1,
An elastic substrate having an adhesive force of 500 gf/inch or more after bonding the surface of the adhesive layer pattern in contact with the non-stretchable pattern and leaving it for 1 hour at 23°C and 50 RH%. In claim 1,
A stretchable substrate wherein the deformation of the non-stretchable pattern is 3% or less when the stretchable substrate is stretched by 20%. In claim 1,
A stretchable substrate wherein the thickness of the stretchable polymer film is 100 μm or more and 1000 μm or less. In claim 1,
A stretchable substrate wherein the stretchability of the stretchable substrate is 20% or more. The stretchable substrate according to any one of claims 1 to 6 and 8 to 14; and
an electronic device provided on a region corresponding to the non-stretchable pattern of the stretchable substrate;
Electronic devices containing. In claim 15,
The electronic device is
An electronic device selected from the group consisting of organic photovoltaic devices, organic transistors, organic solar cells, micro LED devices, and organic light-emitting devices.