Semiconductor device with elasticity

Abstract

To provide a semiconductor device with elasticity that reduces the impact of stretching on semiconductor elements and enables stabilization of their operation.SOLUTION: A semiconductor device comprises: a flexible elastic resin substrate 2; a non-elastic resin substrate 3 placed on the flexible elastic resin substrate 2; a semiconductor element 4 placed on the non-elastic resin substrate 3; an electrode layer 6 placed on the non-elastic resin substrate 3 and electrically connected to the semiconductor element 4; and wiring layers 9a, 9b provided on the surface side of the flexible elastic resin substrate 2 facing the non-elastic resin substrate 3. The wiring layers 9a and 9b are formed from a flowable metallic material comprising metal particles dispersed in a liquid metal, one end of each is electrically connected to the electrode layer 6 via a connection portion 11, and the connection portion 11 consists of a first metal film 13a on the electrode layer 6 side that is difficult to alloy with the liquid metal and a multilayer film comprising at least two layers including a second metal film 13b that readily alloys with the liquid metal on the wiring layer 9a, 9b side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a semiconductor device having elasticity. [Background technology]

[0002] For example, there are semiconductor devices with stretchability (see, for example, Patent Documents 1 and 2 below). Such stretchable semiconductor devices are necessary for driving electronic devices such as organic electroluminescence (EL) displays that can be deformed into three-dimensional shapes such as spherical or free-form surfaces, and pressure-sensitive sensors.

[0003] Specifically, Patent Document 1 below discloses a stretchable semiconductor element comprising a flexible substrate having a support surface and a semiconductor structure having a curved inner surface, at least a portion of the curved inner surface being bonded to the support surface of the flexible substrate.

[0004] Furthermore, Patent Document 2 below discloses a stretchable device in which one or more semiconductor elements are formed on a resin substrate, and a semiconductor-mounted substrate configured by covering the semiconductor elements with an inner sealing layer is embedded in one or more stretchable resin films made of elastomer, a conductive circuit connected to the semiconductor elements is formed in the stretchable resin film, and the periphery of the semiconductor-mounted substrate is covered with an outer sealing layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-281406 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-149364 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-described stretchable semiconductor device, a semiconductor element such as a thin film transistor (TFT) is formed on a stretchable substrate. However, in conventional semiconductor devices, when the substrate is stretched, peeling easily occurs between the substrate (stretchable portion) and the semiconductor element (non-stretchable portion), which can cause instability in the characteristics of the semiconductor element.

[0007] Furthermore, when the substrate is expanded or contracted, it becomes difficult to maintain electrical connection between the wiring on the expanding or contracting substrate side and the electrodes on the semiconductor element side, which may result in disconnection.

[0008] The present invention has been proposed in consideration of the above-mentioned conventional circumstances, and aims to provide a semiconductor device having elasticity that reduces the impact of expansion and contraction on semiconductor elements and enables stabilization of the operation of the semiconductor elements. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides the following means. [1] A stretchable resin substrate that can be stretched freely; a non-stretchable resin substrate disposed on the stretchable resin substrate; a semiconductor element disposed on the non-elastic resin substrate; an electrode layer disposed on the non-elastic resin substrate and electrically connected to the semiconductor element; a wiring layer provided in a stretchable manner on a surface of the stretchable resin substrate facing the non-stretchable resin substrate, the wiring layer is formed of a fluid metal material in which metal particles are dispersed in a liquid metal, and one end side of the wiring layer is electrically connected to the electrode layer via a connection portion; The connection portion is a stretchable semiconductor device characterized in that it is composed of a laminated film of at least two layers, including a first metal film that is difficult to alloy with the liquid metal on the electrode layer side and a second metal film that is easy to alloy with the liquid metal on the wiring layer side. [2] The stretchable semiconductor device according to [1], wherein the liquid metal is a eutectic alloy containing at least Ga and In or a eutectic alloy containing Ga, In, and Sn. [3] The stretchable semiconductor device according to [1], wherein the metal particles contain at least one selected from Ni, Au, Ag, Cu, and Si. [4] The stretchable semiconductor device according to [1], wherein the first metal film contains at least one selected from Mo, Ni, Nb, and W. [5] The stretchable semiconductor device according to [1], wherein the second metal film contains at least one selected from Au, Cu, and Al. [6] The stretchable semiconductor device according to [1], wherein the second metal film constitutes at least a part of the electrode layer. [7] The stretchable resin substrate has adhesiveness, The stretchable semiconductor device according to [1], wherein the non-stretchable resin substrate is attached to the stretchable resin substrate by the adhesive force of the stretchable resin substrate. [8] An adhesive layer is provided on the surface of the stretchable resin substrate facing the non-stretchable resin substrate, The stretchable semiconductor device according to [1], wherein the non-stretchable resin substrate is attached to the stretchable resin substrate via the adhesive layer. [9] A plurality of the non-stretchable resin substrates are arranged side by side within the plane of the stretchable resin substrate, the semiconductor element is disposed on each surface of the plurality of non-elastic resin substrates, The stretchable semiconductor device described in [1], characterized in that the stretchable resin substrate is stretchable between adjacent ones of the plurality of non-stretchable resin substrates. [Effects of the Invention]

[0010] As described above, according to the present invention, it is possible to provide a semiconductor device having elasticity that reduces the effect of expansion and contraction on a semiconductor element and enables stabilization of the operation of the semiconductor element. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a plan view showing a configuration of a semiconductor device according to a first embodiment of the present invention. [Figure 2] 2 is an enlarged cross-sectional view of a main part of the semiconductor device taken along line AA shown in FIG. [Figure 3] 2 is an enlarged cross-sectional view of a main part of the semiconductor device taken along line BB shown in FIG. [Figure 4] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 5] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 6] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 7] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 8] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 9] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 10] 2A to 2C are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device shown in FIG. [Figure 11] 2 is an enlarged cross-sectional view of a main part of the semiconductor device corresponding to line AA in FIG. 1, showing the configuration of the semiconductor device according to the second embodiment of the present invention. [Figure 12] 1. FIG. 4 is an enlarged cross-sectional view of a main part of the semiconductor device corresponding to the line BB shown in FIG. 1, illustrating the configuration of the semiconductor device according to the second embodiment of the present invention. [Figure 13] 1 is a graph showing the results of measuring the characteristics of Samples 1 to 3 of the example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings used in the following description, characteristic portions may be enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may not be the same as in reality. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not necessarily limited to them, and can be implemented with appropriate changes within the scope of the present invention.

[0013] In the drawings shown below, an XYZ Cartesian coordinate system is set, with the X-axis direction being a first direction X within the plane of the semiconductor device, the Y-axis direction being a second direction Y perpendicular to the first direction X within the plane of the semiconductor device, and the Z-axis direction being a third direction Z perpendicular to the plane of the semiconductor device.

[0014] (First embodiment) (Semiconductor Devices) First, as a first embodiment of the present invention, the configuration of a semiconductor device 1A having elasticity as shown in, for example, FIGS. 1 to 3 will be described.

[0015] Fig. 1 is a plan view showing the configuration of semiconductor device 1A. Fig. 2 is an enlarged cross-sectional view of a main part of semiconductor device 1A taken along line AA in Fig. 1. Fig. 3 is an enlarged cross-sectional view of a main part of semiconductor device 1A taken along line BB in Fig. 1.

[0016] As shown in Figures 1 to 3, the semiconductor device 1A of this embodiment comprises a stretchable resin substrate 2 that can be stretched freely, a plurality of non-stretchable resin substrates 3 arranged in a line within the surface of the stretchable resin substrate 2, and a plurality of semiconductor elements 4 arranged on each surface of the non-stretchable resin substrate 3.

[0017] In the semiconductor device 1A of this embodiment, as an example of the semiconductor element 4, a configuration is illustrated in which light-emitting diode (LED) elements (hereinafter referred to as "LED elements 4" as necessary) are arranged in a matrix in a first direction X and a second direction Y that intersect each other (orthogonal in this embodiment) within the plane of the elastic resin substrate 2.

[0018] The stretchable resin substrate 2 is a film substrate containing an acrylic adhesive composition having adhesive properties, and among these, it is preferable to use an acrylic resin which has excellent transparency, weather resistance, and heat resistance, and has excellent conformability to uneven surfaces and excellent adhesive strength and holding power for curved surfaces.

[0019] For example, the stretchable resin substrate 2 can be made of an adhesive acrylic polymer containing 50% by mass or more of a monomer having an acryloyl group and a methacryloyl group as an adhesive acrylic adhesive composition. The stretchable resin substrate 2 may also be made of a tackifying resin, such as a rosin-based tackifying resin, a terpene-based tackifying resin, or an epoxy-based tackifying resin. The resin material constituting the film substrate of the stretchable resin substrate 2 is a resin with a tensile elongation of 100% or more, such as an acrylic resin, a silicone resin, or a styrene-butadiene resin. The thickness of the stretchable resin substrate 2 is preferably 0.005 to 1.5 mm, and more preferably 0.05 to 1 mm.

[0020] The adhesive strength of the stretchable resin substrate 2 is, for example, preferably 5 N / 20 mm or more, more preferably 7 N / 20 mm or more, in terms of 180° peel adhesive strength measured in accordance with "JIS Z 0237." The level of adhesive strength of the stretchable resin substrate 2 is a necessary element for preventing peeling from and integrating with the non-stretchable resin substrate 3, and there is no particular upper limit to the adhesive strength.

[0021] In order to improve the life span and durability of the stretchable resin substrate 2, it is preferable that the stretchable resin substrate 2 has the ability to return to its original shape after being stretched. Specifically, the recovery rate after being stretched 100% is preferably 70% or more, and more preferably 85% or more. If the recovery rate is low, it becomes difficult to obtain durability. It is known that the recovery rate can be adjusted by the degree of crosslinking and average molecular weight of the acrylic polymer, and adjustment is possible by this method.

[0022] The multiple non-stretchable resin substrates 3 are film substrates made of flexible resin (plastic), and are arranged in a matrix in a first direction X and a second direction Y that intersect each other (orthogonal in this embodiment) within the plane of the stretchable resin substrate 2. Furthermore, each non-stretchable resin substrate 3 can be attached to one surface (front surface) of the stretchable resin substrate 2 by the adhesive force of the stretchable resin substrate 2 described above.

[0023] For example, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polycarbonate (PC), nanocellulose, etc. can be used for the non-elastic resin substrate 3. Among these, it is preferable to use PI, which has excellent heat resistance and chemical resistance against thermal baking and chemical treatment required when forming semiconductor elements, etc. The thickness of the non-elastic resin substrate 3 is preferably 0.1 to 100 μm, and more preferably 1 to 10 μm.

[0024] Furthermore, the non-stretchable resin substrate 3 is preferably attached to the stretchable resin substrate 2 via an adhesive layer 5. The adhesive layer 5 is a layer for improving adhesion between the stretchable resin substrate 2, which will be the stretchable portion, and the non-stretchable resin substrate 3, which will be the non-stretchable portion, and is formed on the surface of the non-stretchable resin substrate 3 facing the stretchable resin substrate 2.

[0025] The adhesive layer 5 is made of, for example, a silicon oxide (SiO2) film or a silicon nitride (SiN x The adhesive layer 5 preferably has a thickness of 5 to 200 nm, more preferably 10 to 20 nm.

[0026] The LED element 4 is electrically connected to a first upper electrode layer 6 and a second upper electrode layer 7 disposed on one surface (top surface) of the non-elastic resin substrate 3. For the first upper electrode layer 6 and the second upper electrode layer 7, for example, metals such as titanium (Ti), chromium (Cr), aluminum (Al), molybdenum (Mo), gold (Au), silver (Ag), copper (Cu), alloys of these, or conductive films formed by laminating two or more of these metals can be used.

[0027] The first upper electrode layer 6 and the second upper electrode layer 7 are arranged so as to extend in a first direction X and a second direction Y that intersect each other (orthogonal in this embodiment) on the surface of the non-elastic resin substrate 3, and intersect each other three-dimensionally.

[0028] For this reason, an insulating layer 8 is provided at the intersection of the first upper electrode layer 6 and the second upper electrode layer 7 to electrically insulate the first upper electrode layer 6 from the second upper electrode layer 7. The insulating layer 8 may be made of, for example, silicon nitride (SiN x ) film or silicon oxide (SiO2), etc. can be used.

[0029] One end of the LED element 4 is electrically connected to the first upper electrode layer 6 via an electrode portion 6a protruding in the width direction from the first upper electrode layer 6. The other end of the LED element 4 is electrically connected to the second upper electrode layer 7.

[0030] The semiconductor device 1A of this embodiment may be configured such that a protective layer (not shown) covering at least a part of the LED element 4 is provided on the non-elastic resin substrate 3. The protective layer has the effect of suppressing distortion of the LED element 4 formed on the non-elastic resin substrate 3 and stabilizing the characteristics of the LED element 4.

[0031] The protective layer can be made of an organic film such as an epoxy resin, an olefin resin, an acrylic resin, or a polyimide resin. Among these, it is preferable to use a photoreactive epoxy resin, which can be made into a thick film of 1 μm or more and can be patterned by light. Specifically, a negative photoresist material such as SU-8 can be used. The thickness of the protective layer is preferably 0.1 to 5 μm, and more preferably 1 to 2 μm.

[0032] A pair of first wiring layers 9a, 9b and a pair of second wiring layers 10a, 10b, each having elasticity, are provided on one surface (upper surface) of the elastic resin substrate 2. The first wiring layers 9a, 9b and the second wiring layers 10a, 10b are formed of, for example, a fluid metal material in which metal particles are dispersed in a liquid metal.

[0033] The liquid metal can be, for example, a eutectic alloy containing gallium (Ga) and indium (In), or a eutectic alloy containing Ga, In, and tin (Sn).The melting point can be changed by adjusting the amount of In and Sn added to Ga as the main component.

[0034] Metal particles can be, for example, nickel (Ni), Au, Ag, Cu, or Si. The liquid metals mentioned above have very strong atomic forces, resulting in high surface energy and very poor wettability. Therefore, adding the above-mentioned metal particles can improve wettability.

[0035] For example, by mixing 1 to 20 mass % of Ni particles with an average particle size of 1 to 50 μm into a liquid metal containing gallium (Ga) and indium (In), a paste is formed, which makes it possible to form the first wiring layers 9a, 9b and the second wiring layers 10a, 10b by printing.

[0036] The pair of first wiring layers 9a, 9b are provided extending in the first direction X so as to electrically connect adjacent ones of the plurality of non-stretchable resin substrates 3 in the first direction X. In other words, the pair of first wiring layers 9a, 9b are shared between adjacent ones of the plurality of non-stretchable resin substrates 3 in the first direction X.

[0037] On the other hand, the pair of second wiring layers 10a, 10b are provided extending in the second direction Y so as to electrically connect the plurality of non-stretchable resin substrates 3 that are adjacent to each other in the second direction Y. In other words, the pair of second wiring layers 10a, 10b are shared between the plurality of non-stretchable resin substrates 3 that are adjacent to each other in the second direction Y.

[0038] One end side of the pair of first wiring layers 9 a, 9 b is disposed extending onto the non-elastic resin substrate 3 and is electrically connected to the first upper electrode layer 6 via a first connection portion 11 .

[0039] On the other hand, one end side of the pair of second wiring layers 10a, 10b is extended onto the non-elastic resin substrate 3 and is electrically connected to the second upper electrode layer 7 via a second connection portion 12.

[0040] The first connection portion 11 is composed of a laminated film of at least two layers, including a first metal film 13a that is easily alloyed with liquid metal on the side of the first wiring layers 9a, 9b, and a second metal film 13b that is difficult to alloy with liquid metal on the side of the first upper electrode layer 6.

[0041] Similarly, the second connection portion 12 is composed of a laminated film of at least two layers, including a first metal film 13a that is easily alloyed with liquid metal on the side of the second wiring layers 10a, 10b, and a second metal film 13b that is difficult to alloy with liquid metal on the side of the second upper electrode layer 7.

[0042] The first metal film 13a may be made of, for example, a metal such as Au, Cu, or Al, or an alloy thereof, or a conductive film in which two or more of these metals are stacked.

[0043] The second metal film 13b may be made of, for example, a metal such as Ni, niobium (Nb), or tungsten (W), or an alloy thereof, or a conductive film in which two or more of these metals are stacked.

[0044] The first metal film 13a has higher wettability to liquid metal than the second metal film 13b, and it is possible to form a good pattern while ensuring the fluidity of the fluid metal material when forming the first wiring layers 9a, 9b and the second wiring layers 10a, 10b on this first metal film 13a.

[0045] On the other hand, the second metal film 13b is located between the first metal film 13a and the first and second upper electrode layers 6 and 7, thereby making it possible to prevent the first and second upper electrode layers 6 and 7 from being alloyed by the liquid metal.

[0046] In the semiconductor device 1A of this embodiment having the above-described configuration, the stretchable resin substrate 2 is stretchable between adjacent ones of the plurality of non-stretchable resin substrates 3.

[0047] As a result, when the stretchable resin substrate 2 is stretched in the first direction X and the second direction Y, the LED element 4 is provided on the non-stretchable resin substrate 3, which becomes the non-stretchable portion, and therefore it is possible to reduce the effect of stretching and contracting of the stretchable resin substrate 2 on this LED element 4.

[0048] Furthermore, in the semiconductor device 1A of this embodiment, as shown in Figures 2 and 3, the electrical connection between the first wiring layers 9a, 9b and the first upper electrode layer 6 via the above-mentioned first connection portion 11, and the electrical connection between the second wiring layers 10a, 10b and the second upper electrode layer 7 via the second connection portion 12 can each be maintained in a stable state for a long period of time.

[0049] Therefore, in the semiconductor device 1A of this embodiment, it is possible to reduce the influence of the expansion and contraction of the expandable resin substrate 2 on the LED element 4, and to stabilize the operation of the LED element 4.

[0050] (Method of manufacturing a semiconductor device) Next, a method for manufacturing the semiconductor device 1A will be described with reference to FIGS. 4 to 10 are cross-sectional views for sequentially explaining the manufacturing process of the semiconductor device 1A. Also, Figs. 4 to 10 show cross-sectional views corresponding to the line AA shown in Fig. 1.

[0051] 4, a non-stretchable resin base material 30 that will become the plurality of non-stretchable resin substrates 3 is formed on a first support substrate 21. Specifically, a glass substrate is used as the first support substrate 21, and a coating liquid containing PI that will become the non-stretchable resin substrates 3 is applied onto this first support substrate 21 by spin coating to form a coating film, and then this coating film is dried (baked) to form the non-stretchable resin base material 30 made of a PI film.

[0052] Next, as shown in Figure 5, the surrounding areas of the non-stretchable resin base material 30 that will become each non-stretchable resin substrate 3 are removed by dry etching or wet etching using photolithography technology to form multiple non-stretchable resin substrates 3.

[0053] Next, as shown in FIG. 6, a first upper electrode layer 6, an insulating layer 8, a second upper electrode layer 7, a first connecting portion 11 and a second connecting portion 12 are formed on each non-elastic resin substrate 3.

[0054] Next, as shown in FIG. 7, a second support substrate 23 is attached onto the plurality of non-stretchable resin substrates 3 via a removable film tape 22.

[0055] Next, the first support substrate 21 is peeled off, as shown in Fig. 8. Specifically, using laser lift-off, laser light is irradiated from the first support substrate 21 side to ablate the interfaces between the plurality of non-stretchable resin substrates 3 and the first support substrate 21, thereby removing the first support substrate 21 peeled off from the plurality of non-stretchable resin substrates 3.

[0056] Next, as shown in FIG. 9, the stretchable resin substrate 2 is attached onto the plurality of non-stretchable resin substrates 3 via the adhesive layer 5.

[0057] 10, the second support substrate 23 is peeled off and removed together with the removable film tape 22 from the plurality of non-stretchable resin substrates 3. Thereafter, the first wiring layers 9a, 9b and the second wiring layers 10a, 10b are formed on the stretchable resin substrate 2 using the fluid metal material in which metal particles are dispersed in the above-mentioned liquid metal.

[0058] To form the pattern of the first wiring layers 9a, 9b and the second wiring layers 10a, 10b, a printing method such as screen printing, inkjet printing, flexographic printing, gravure printing, offset printing, aerosol jet printing, or stencil printing, or an ejection method using a displacer, can be used to pattern a fluid metal material into the shape of the first wiring layers 9a, 9b and the second wiring layers 10a, 10b, thereby forming the first wiring layers 9a, 9b and the second wiring layers 10a, 10b having elasticity.

[0059] Thereafter, the LED elements 4 are mounted on each of the non-stretchable resin substrates 3 so as to be electrically connected to the first upper electrode layer 6 and the second upper electrode layer 7 of each of the non-stretchable resin substrates 3 . By going through the above steps, the semiconductor device 1A shown in FIG. 1 can be fabricated.

[0060] The manufacturing method of the semiconductor device 1A of this embodiment reduces the impact on the LED element 4 caused by the expansion and contraction of the above-mentioned elastic resin substrate 2, making it possible to manufacture the semiconductor device 1A with high yield, which enables stabilization of the operation of the LED element 4.

[0061] (Second embodiment) Next, as a second embodiment of the present invention, a semiconductor device 1B shown in, for example, FIGS. 11 and 12 will be described.

[0062] Note that Fig. 11 is an enlarged cross-sectional view of a main part of semiconductor device 1B corresponding to line AA shown in Fig. 1. Fig. 12 is an enlarged cross-sectional view of a main part of semiconductor device 1B corresponding to line BB shown in Fig. 1. In the following description, the same parts as those in semiconductor device 1A will not be described and will be denoted by the same reference numerals in the drawings.

[0063] As shown in FIGS. 11 and 12, the semiconductor device 1B of this embodiment has basically the same configuration as the semiconductor device 1A, except for the following configuration.

[0064] 11, in the first connection portion 11, the second metal film 13b forms at least a part of the first upper electrode layer 6. In this embodiment, the first upper electrode layer 6 is made of the same conductive film as the second metal film 13b, so that the second metal film 13b is formed integrally with the first upper electrode layer 6.

[0065] 12, in the second connection portion 12, the second metal film 13b forms at least a part of the second upper electrode layer 7. In this embodiment, the second upper electrode layer 7 is made of the same conductive film as the second metal film 13b, so that the second metal film 13b is formed integrally with the second upper electrode layer 7.

[0066] In this configuration, as in the semiconductor device 1A described above, it is possible to form a good pattern while ensuring the fluidity of the fluid metal material when forming the first wiring layers 9a, 9b and the second wiring layers 10a, 10b using the first metal film 13a, and it is also possible to prevent the first upper electrode layer 6 and the second upper electrode layer 7 from being alloyed with the liquid metal using the second metal film 13b.

[0067] As a result, in the semiconductor device 1B of this embodiment, the electrical connection between the first wiring layers 9a, 9b and the first upper electrode layer 6 via the above-mentioned first connection portion 11, and the electrical connection between the second wiring layers 10a, 10b and the second upper electrode layer 7 via the second connection portion 12 can each be maintained in a stable state for a long period of time.

[0068] Therefore, in the semiconductor device 1B of this embodiment, it is possible to reduce the influence of the expansion and contraction of the stretchable resin substrate 2 on the LED element 4, and to stabilize the operation of the LED element 4.

[0069] The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0070] For example, the stretchable resin substrate 2 is not necessarily limited to the one having the above-mentioned adhesiveness, and may be one without adhesiveness. In this case, the non-stretchable resin substrate 3 may be attached to the stretchable resin substrate 2 via the adhesive layer 5.

[0071] Furthermore, the first wiring layers 9a, 9b and the second wiring layers 10a, 10b may be configured to be embedded in grooves formed in the stretchable resin substrate 2, or may be configured to be embedded in an insulating layer (not shown) formed in the stretchable resin substrate 2.

[0072] Furthermore, the semiconductor devices 1A and 1B of this embodiment are configured to include LED elements 4 as semiconductor elements, but by forming TFTs or the like on each non-stretchable resin substrate 3 and each non-stretchable resin substrate 3 constituting one pixel device, it is possible to realize a stretchable display that can be stretched and contracted, and to form a display that can be deformed into a three-dimensional shape such as a spherical surface or a free-form surface. When configuring a pixel device, it is also possible to use light-emitting elements such as organic electroluminescence (EL) elements instead of the above-mentioned LED elements 4.

[0073] Furthermore, the semiconductor device to which the present invention is applied is not necessarily limited to a configuration having the above-mentioned light-emitting element, and it is also possible to use an electronic device having semiconductor elements such as a light-receiving element, a strain sensor, or a pressure sensor. [Example]

[0074] The effects of the present invention will be made clearer by the following examples. Note that the present invention is not limited to the following examples and can be practiced with appropriate modifications within the scope of the present invention.

[0075] In this example, a polyimide film was first formed on a glass substrate to serve as a non-stretchable substrate. To form the polyimide film, polyimide varnish (manufactured by Ube Industries, Ltd.) was applied by spin coating, followed by heat treatment at 400°C for 1 hour in a nitrogen atmosphere. This resulted in a polyimide film with a thickness of approximately 15 μm.

[0076] Next, a sputtering device was used to process the polyimide film by photolithography and dry etching using a molybdenum alloy, thereby forming a plurality of island-shaped polyimide films.

[0077] Next, we fabricated Sample 1, in which a Mo film and an Au film were laminated in that order on a polyimide film via a metal mask; Sample 2, in which an Au film was formed; Sample 3, in which a Mo film was formed; and Sample 4, in which an Al film was formed.

[0078] Wiring patterns were printed on the metal films of these four samples 1 to 4 using a fluid metal material made of a liquid metal made of GaIn eutectic alloy with Ni particles dispersed in it. The wiring resistance R of these four samples 1 to 4 was then measured, and the change over time from the initial resistance value R0 was determined. The measurement results are shown in Figure 13.

[0079] As shown in FIG. 13, in Sample 1, the wiring pattern was well formed, the change in wiring resistance over time was small, and a stable state could be maintained for a long period of time.

[0080] On the other hand, in Sample 2, although the wiring pattern was well formed, the Au film was easily alloyed with the liquid metal, so the wiring resistance changed significantly over time, and reliability was impaired.

[0081] On the other hand, in Sample 3, the change in wiring resistance over time was small, but the Mo film was easily alloyed with liquid metal, so the wettability was poor and it was difficult to form a wiring pattern by printing.

[0082] On the other hand, in sample 4, the liquid metal eroded the Al film, causing a break in the wiring, making it impossible to measure the wiring resistance. [Explanation of symbols]

[0083] REFERENCE SIGNS LIST 1A, 1B... semiconductor device 2... stretchable resin substrate 3... non-stretchable resin substrate 4... semiconductor element (LED element) 5... adhesion layer 6... first upper electrode layer 7... second upper electrode layer 8... insulating layer 9a, 9b... first wiring layer 10a, 10b... second wiring layer 11... first connection portion 12... second connection portion 13a... first metal film 13b... second metal film

Claims

1. A stretchable resin substrate that can be stretched freely; a non-stretchable resin substrate disposed on the stretchable resin substrate; a semiconductor element disposed on the non-elastic resin substrate; an electrode layer disposed on the non-elastic resin substrate and electrically connected to the semiconductor element; a wiring layer provided in a stretchable manner on a surface of the stretchable resin substrate facing the non-stretchable resin substrate, the wiring layer is formed of a fluid metal material in which metal particles are dispersed in a liquid metal, and one end side of the wiring layer is electrically connected to the electrode layer via a connection portion; The connection portion is a stretchable semiconductor device characterized in that it is composed of a laminated film of at least two layers, including a first metal film that is easily alloyed with the liquid metal on the wiring layer side and a second metal film that is difficult to alloy with the liquid metal on the electrode layer side.

2. 2. The stretchable semiconductor device according to claim 1, wherein the liquid metal is a eutectic alloy containing at least Ga and In or a eutectic alloy containing Ga, In, and Sn.

3. 2. The stretchable semiconductor device according to claim 1, wherein the metal particles contain at least one selected from the group consisting of Ni, Au, Ag, Cu, and Si.

4. 2. The stretchable semiconductor device according to claim 1, wherein the first metal film contains at least one selected from the group consisting of Au, Cu, and Al.

5. The stretchable semiconductor device according to claim 1 , wherein the second metal film contains at least one selected from the group consisting of Mo, Ni, Nb, and W.

6. The stretchable semiconductor device according to claim 1 , wherein the second metal film constitutes at least a part of the electrode layer.

7. The stretchable resin substrate has adhesiveness, 2. The stretchable semiconductor device according to claim 1, wherein the non-stretchable resin substrate is attached to the stretchable resin substrate by the adhesive force of the stretchable resin substrate.

8. an adhesive layer provided on a surface of the stretchable resin substrate facing the non-stretchable resin substrate; 2. The stretchable semiconductor device according to claim 1, wherein the non-stretchable resin substrate is attached to the stretchable resin substrate via the adhesive layer.

9. a plurality of the non-stretchable resin substrates are arranged side by side within the plane of the stretchable resin substrate; the semiconductor element is disposed on each surface of the plurality of non-elastic resin substrates, 2. The semiconductor device having elasticity according to claim 1, wherein the elastic resin substrate is elastically stretchable between adjacent ones of the plurality of non-elastic resin substrates.

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