Electronic device, electronic component, contact lens type electronic device, and method for manufacturing electronic device

Abstract

This electronic device comprises: a plurality of devices; wiring that electrically connects the respective devices of the plurality of devices; and a substrate on which the wiring is formed and in which a slit is formed. The substrate is preferably bent so as to follow along a prescribed curved surface. The slit is preferably formed so as to extend along a direction substantially orthogonal to a gradient vector for a prescribed direction of points on the prescribed curved surface. Provided through this configuration is an electronic device that suppresses reduction in reliability occurring when a substrate has been bent so as to follow along an arbitrary curved surface.

Description

[Technical field]

[0001] The present invention relates to an electronic device, an electronic component, a contact lens type electronic device, and a method for manufacturing an electronic device. [Background technology]

[0002] Conventionally, flexible FPC (Flexible Printed Circuits) substrates have been used in electronic devices.

[0003] Moreover, Patent Document 1 discloses an electronic device in which a substrate formed in a flat plate shape is bent so as to imitate a spherical contact lens. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2016-540569 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a flat substrate is bent to conform to any curved surface other than a developable curved surface such as a sphere (cylinder, cone, and tangent curved surface), a pleated structure is formed, causing the wiring formed on the substrate to bend, decreasing the reliability of the electronic device. Therefore, there has been a demand for an electronic device in which the decrease in reliability when the substrate is bent to conform to any curved surface is suppressed.

[0006] The present invention has been made in consideration of the above, and aims to provide an electronic device, an electronic component, a contact lens-type electronic device, and a method for manufacturing an electronic device in which a decrease in reliability is suppressed when a substrate is bent to conform to an arbitrary curved surface. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the objective, an electronic device according to one embodiment of the present invention is characterized in that it comprises a plurality of devices, wiring electrically connecting each of the plurality of devices, and a substrate on which the wiring is formed and in which a slit is formed.

[0008] In addition, in an electronic device according to one aspect of the present invention, the substrate is bent so as to follow a predetermined curved surface.

[0009] In addition, an electronic device according to one aspect of the present invention is characterized in that the slits are formed to extend in a direction approximately perpendicular to a gradient vector of each point on the specified curved surface with respect to a specified direction.

[0010] In addition, an electronic device according to one aspect of the present invention is characterized in that the slit is formed to extend in a direction approximately perpendicular to the gradient vector at a position where the magnitude of the gradient vector is large.

[0011] In addition, an electronic device according to one aspect of the present invention is characterized in that the substrate has a plurality of slits formed thereon, the slits being parallel curved lines.

[0012] In addition, an electronic device according to one aspect of the present invention is characterized in that the wiring is formed to extend in a direction approximately perpendicular to a gradient vector of each point on the specified curved surface with respect to a specified direction.

[0013] In addition, an electronic device according to one aspect of the present invention is characterized in that the wiring is formed so as to extend in a direction approximately perpendicular to the gradient vector at a position where the magnitude of the gradient vector is large.

[0014] In addition, the electronic device according to one aspect of the present invention is characterized in that the substrate has dummy slits formed in areas where the wiring is not formed.

[0015] In addition, the electronic device according to one aspect of the present invention is characterized in that the substrate is a hollow disk curved into a spherical shape.

[0016] In addition, the electronic device according to one aspect of the present invention is characterized in that the devices are arranged at approximately equal intervals so that the central angles with respect to the center of the disk are equal.

[0017] Moreover, an electronic component according to one aspect of the present invention is characterized in that an electronic device is encapsulated in a silicone elastomer.

[0018] A contact lens type electronic device according to one aspect of the present invention is characterized in that an electronic component is sandwiched and sealed between lens substrates.

[0019] Furthermore, a manufacturing method for an electronic device according to one embodiment of the present invention is characterized in that it includes a step of forming wiring on a substrate, a step of electrically connecting a plurality of devices to the wiring and placing them on the substrate, and a step of forming slits in the substrate. Effect of the Invention

[0020] According to the present invention, it is possible to realize an electronic device, an electronic component, a contact lens-type electronic device, and a method for manufacturing an electronic device in which a decrease in reliability is suppressed when a substrate is bent to conform to an arbitrary curved surface. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an electronic device according to an embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing the configuration of an electronic component using the electronic device shown in FIG. [Diagram 3] FIG. 3 is a schematic diagram showing the configuration of a contact lens type electronic device using the electronic component shown in FIG. [Figure 4] FIG. 4 is a schematic diagram showing a configuration of an electronic device according to a modified example of the embodiment. [Diagram 5]FIG. 5 is a diagram illustrating an example of a curved surface. [Figure 6] FIG. 6 is a diagram showing the gradient vector of a curved surface projected onto the xy plane. [Figure 7] FIG. 7 is a diagram showing a state in which slits are formed in a substrate so as to be perpendicular to the gradient vector. [Figure 8] FIG. 8 is a diagram showing how the substrate is bent to fit a curved surface. [Figure 9] FIG. 9 is a diagram showing how the substrate is bent to conform to a cylinder. [Figure 10] FIG. 10 is a diagram showing the gradient vector of a cylinder projected onto the xy plane. [Figure 11] FIG. 11 is a diagram showing how a substrate is bent to conform to a portion of a sphere. [Figure 12] FIG. 12 is a diagram showing the gradient vector of a part of a sphere projected onto the xy plane. [Figure 13] FIG. 13 is a diagram showing a state in which slits are formed in a substrate so as to be perpendicular to the gradient vector when the curved surface is spherical. [Figure 14] FIG. 14 is a diagram showing how the substrate is bent to follow the curved surface when the curved surface is spherical. [Figure 15] FIG. 15 is a flowchart of a method for manufacturing a contact lens type electronic device using an electronic device according to a modified example of the embodiment. [Figure 16] FIG. 16 is a diagram showing how wiring is formed on a substrate. [Figure 17] FIG. 17 is a diagram showing how adhesive is applied to wiring. [Figure 18] FIG. 18 is a diagram showing how the device is placed on the substrate. [Figure 19] FIG. 19 is a diagram showing how slits are formed in a substrate. [Figure 20] FIG. 20 is a diagram showing a state in which slits are formed in the substrate. [Figure 21] FIG. 21 is a diagram showing a silicone mold. [Figure 22] FIG. 22 is a diagram showing how an electronic device is placed on the silicone elastomer. [Figure 23] FIG. 23 is a diagram showing an electronic device encapsulated in a silicone elastomer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the electronic device, electronic component, contact lens-type electronic device, and method for manufacturing the electronic device of the present invention will be described in detail with reference to embodiments, but the present invention is not limited thereto.

[0023] (Embodiment) [Configuration of Electronic Device] Fig. 1 is a schematic diagram showing the configuration of an electronic device according to an embodiment. As shown in Fig. 1, an electronic device 10 according to the present embodiment includes a plurality of devices 11, wiring 12 electrically connecting each of the plurality of devices 11, a substrate 13 on which the wiring 12 is formed and in which slits 13a are formed, and a device region 14 electrically connecting the devices 11 and the wiring 12.

[0024] The devices 11 are not particularly limited, but may be, for example, an arithmetic circuit such as a CPU (Central Processing Unit), a storage device such as a memory, a battery capable of storing electricity, a receiving circuit for receiving various signals, an output circuit for outputting various signals, etc. The devices 11 are arranged at approximately equal intervals in the disc-shaped electronic device 10 so that the central angles with respect to the center of the disc are equal.

[0025] The wiring 12 is a conductor such as a metal or alloy patterned on the substrate 13, and is, for example, an electrical wiring made of Cu or Au. The wiring 12 is formed so as to extend in a direction substantially perpendicular to a gradient vector of each point on a predetermined curved surface with respect to a predetermined direction. In the electronic device 10, the predetermined direction can be set arbitrarily, but it is preferable to set it so as to simplify the structure of the slit 13a as much as possible, and in this embodiment, it is set to the optical axis direction of a contact lens type electronic device described later.

[0026] The substrate 13 is an FPC substrate made of insulating resin such as polyimide, and is bent to conform to a predetermined curved surface. The predetermined curved surface is not particularly limited, but may be, for example, a spherical (including spherical and aspherical) curved surface like an eyeball, and the substrate 13 is, for example, a hollow disk bent into a spherical shape. The substrate 13 is formed with a plurality of slits 13a that are parallel curved lines parallel to each other. In addition, a circular hollow portion 13b is formed in the center of the substrate 13. The hollow portion 13b is preferably, for example, 8 mm or more in diameter so as not to block the field of vision of a wearer wearing a contact lens type electronic device, which will be described later.

[0027] The slit 13a is formed so as to extend in a direction substantially perpendicular to the gradient vector of each point on the predetermined curved surface in a predetermined direction.

[0028] The device region 14 is an electrode pad that electrically connects the device 11 and the wiring 12. However, the device 11 and the wiring 12 may be directly electrically connected, in which case the device region 14 is not necessary.

[0029] [Electronic component configuration] Fig. 2 is a schematic diagram showing the configuration of an electronic component using the electronic device shown in Fig. 1. As shown in Fig. 2, an electronic component 20 is obtained by encapsulating the electronic device 10 in a silicone elastomer 21. Encapsulating the electronic device 10 in the silicone elastomer 21 makes it easier to handle. Furthermore, since the entire electronic device 10 is covered with the silicone elastomer 21, waterproofing is achieved.

[0030] [Configuration of the contact lens type electronic device] Fig. 3 is a schematic diagram showing the configuration of a contact lens type electronic device using the electronic component shown in Fig. 2. As shown in Fig. 3, a contact lens type electronic device 30 has an electronic component 20 sandwiched and sealed between lens substrates 31. By sealing the electronic component 20 in the lens substrate 31, it becomes possible to wear the electronic device on an eye as a contact lens.

[0031] The lens substrate 31 is a soft contact lens made of pHEMA (polyhydroxyethyl methacrylate), SHG (silicone hydrogel), etc. However, the lens substrate 31 may also be a hard contact lens.

[0032] (Modification) Fig. 4 is a schematic diagram showing the configuration of an electronic device according to a modified example of the embodiment. As shown in Fig. 4, a dummy slit 13Ac is formed in a region A shown by a dashed line in which no wiring 12 is formed on a substrate 13 of an electronic device 10A. By forming the dummy slit 13Ac, the rigidity of the substrate 13 is reduced, and the substrate 13 can be made to conform to a curved surface.

[0033] [Method of forming slits] Next, a method for forming the slits 13a will be described. As described above, the slits 13a are preferably formed so as to extend in a direction substantially perpendicular to the gradient vector of each point on a predetermined curved surface in a predetermined direction.

[0034] Fig. 5 is a diagram showing an example of a curved surface. As shown in Fig. 5, it is assumed that there is a curved surface expressed by z=f(x, y), and a certain point on this curved surface is designated as point P(x, y, z).

[0035] Here, the gradient vector of point P(x, y, z) is expressed as ∇f(x, y) = (∂f / ∂x, ∂f / ∂y), and the larger the gradient in the z direction, the larger the absolute value of the gradient vector ∇f. Also, the gradient vector ∇f is a vector contained in a plane perpendicular to the z axis. The magnitude and direction of the gradient vector ∇f of each point changes depending on how the z direction is determined, but it is preferable to determine the z direction in a way that makes the slit structure as simple as possible.

[0036] FIG. 6 is a diagram showing a state where the gradient vector of a curved surface is projected onto the xy plane. FIG. 6 is a diagram showing the gradient vector ∇f calculated at each point of the curved surface expressed by z=f(x,y) and projected onto the xy plane. The slits 13a may be formed so as to extend in a direction perpendicular to the gradient vector ∇f(x,y)=(∂f / ∂x,∂f / ∂y) at each point. In other words, the slits 13a are formed so that the gradient vector ∇f(x,y) and the slits 13a are perpendicular to each other while the substrate 13 is fitted to the curved surface. At this time, it is preferable that many slits 13a are formed so as to be approximately perpendicular to the gradient vector ∇f at positions where the magnitude |∇f(x,y)| of the gradient vector ∇f(x,y) is large (the gradient is steep).

[0037] Fig. 7 is a diagram showing a state where a slit is formed in a substrate so as to be perpendicular to the gradient vector. As shown in Fig. 7, assume that a slit 13a is formed in substrate 13. Then, substrate 13 with this slit 13a formed therein is made to conform to a curved surface. Then, gradient vector ∇f(x, y) and slit 13a are perpendicular to each other.

[0038] FIG. 8 is a diagram showing a state in which the substrate is bent to follow a curved surface. As shown in FIG. 8, when the substrate 13 is bent to follow a curved surface, the formation of the slits 13a makes it difficult for a pleated structure to be formed compared to when the slits are not formed. In particular, in a direction perpendicular to the gradient vector ∇f(x,y), the flat substrate 13 is likely to be left over from the curved surface, and a pleated structure is likely to be formed. However, since the gradient vector ∇f(x,y) and the slits 13a are perpendicular to each other, the slits 13a expand the excess portion of the substrate 13 from the curved surface, and the occurrence of the pleated structure can be efficiently suppressed. As a result, according to the embodiment, it is possible to suppress a decrease in reliability when the substrate 13 is bent to follow an arbitrary curved surface.

[0039] Next, as an example of making the substrate conform to a curved surface, an example of making the substrate conform to a part of a cylinder and a circle will be described. However, the curved surface may be any curved surface and is not limited to a cylinder or a circle.

[0040] [Example of a cylinder] FIG. 9 is a diagram showing how a substrate is bent to conform to a cylinder. As shown in FIG. 9, the substrate 100 is made to conform to a cylinder of radius r1. For a cylinder, the structure of the slit 100a can be simplified most by setting the direction from the center of the cylinder toward one direction on the outer periphery as the z direction. FIG. 10 is a diagram showing the gradient vector of the cylinder projected onto the xy plane. FIG. 10 is a diagram in which the gradient vector ∇f is calculated at each point of the cylinder and projected onto the xy plane. Here, the cylinder has a y 2 +z 2 =r1 2 Since z=√(r1 2 -y 2 )=f(x,y). Therefore, ∇f=(∂f / ∂x,∂f / ∂y)=(0,2y / √(r1 2 -y 2 )) the gradient vector of each point can be calculated. In a cylinder, the gradient vector ∇f becomes larger toward the upper end or the lower end of the cylinder shown in Fig. 10, so it is preferable to increase the number of slits 100a toward both side faces of the cylinder (directions in which z becomes smaller) as shown in Fig. 9.

[0041] [Example of part of a ball] FIG. 11 is a diagram showing how a substrate is bent to conform to a portion of a sphere. As shown in FIG. 11, the substrate 200 is made to conform to a sphere of radius r2. For the portion of the sphere, the structure of the slit 200a can be simplified most by setting the direction from the center of the sphere toward the apex of the portion of the sphere that forms a convex shape as the z direction. This z direction corresponds to the optical axis direction of the contact lens type electronic device 30. FIG. 12 is a diagram showing how the gradient vector of the portion of the sphere is projected onto the xy plane. FIG. 12 is a diagram showing the gradient vector ∇f calculated at each point of the portion of the sphere and projected onto the xy plane. Here, the sphere is x 2 +y 2 +z 2 =r2 2 Since z=√(r2 2 -x 2 -y 2 )=f(x,y). Therefore, ∇f=(∂f / ∂x,∂f / ∂y)=(-2x / √(r22 -x 2 -y 2 ),-2y / √(r2 2 -x 2 -y 2 ))≈(-2x / z,-2y / z), the gradient vector of each point can be calculated. In a sphere, the gradient vector ∇f becomes larger toward the outer periphery of the circle shown in Fig. 12, so it is preferable to increase the number of slits 200a toward the outside of the circle (the direction in which z becomes smaller) as shown in Fig. 11.

[0042] Next, the slits 13a of the substrate 13 will be described. Fig. 13 is a diagram showing a state in which slits are formed in a substrate so as to be perpendicular to a gradient vector when the curved surface is spherical. As shown in Fig. 13, when the curved surface is spherical, slits 13a are formed as parallel curves concentrically from the center of the disk-shaped substrate 13. At this time, it is preferable that the number of slits 13a formed increases toward the outside of the substrate 13.

[0043] Fig. 14 is a diagram showing how the substrate is bent to follow the curved surface when the curved surface is spherical. As shown in Fig. 14, the more the substrate 13 is toward the periphery of the substrate 13, the more the substrate 13 is left over from the spherical surface. However, the slits 13a expand the excess portion of the slits 13a toward the periphery, so that the occurrence of a pleated structure can be suppressed.

[0044] In addition, it is preferable that the gradient vector ∇f(x, y) and the slit 13a are perpendicular to each other. For example, if the angle between the gradient vector ∇f(x, y) and the slit 13a is 60° or more, the pleat structure can be sufficiently suppressed.

[0045] Another possible method for suppressing the pleated structure is to heat and melt a flat substrate so that it conforms to the curved surface. However, this would result in stress concentration at the joint between the wiring that conforms to the curved surface along with the substrate and the non-bending device, reducing the reliability of the electronic device.

[0046] Another possible method for suppressing the pleated structure is to bond the device to a substrate formed into a curved surface, but this requires highly accurate alignment of the substrate and the device, increasing manufacturing costs.

[0047] [Method of Manufacturing Electronic Device] A method for manufacturing the electronic device 10A shown in FIG. 4 will be described below.

[0048] Fig. 15 is a flow chart of a method for manufacturing a contact lens type electronic device using an electronic device according to a modified example of the embodiment. As shown in Fig. 15, first, wiring 12 is formed on a substrate 13 (step S1). Fig. 16 is a diagram showing a state in which wiring is formed on a substrate. As shown in Fig. 16, wiring made of a conductive metal or alloy is formed on a flat substrate 13.

[0049] Next, the devices 11 are placed on the substrate 13 (step S2). At this time, the devices 11 and the wiring 12 are electrically connected. FIG. 17 is a diagram showing how adhesive is applied to the wiring. As shown in FIG. 17, a conductive adhesive is applied onto the wiring 12. FIG. 18 is a diagram showing how the devices are placed on the substrate. As shown in FIG. 18, by placing the devices 11 on the applied adhesive, each device 11 and the wiring 12 are electrically connected, and the devices 11 are placed on the substrate 13.

[0050] Thereafter, slits 13a are formed in substrate 13 (step S3). Fig. 19 is a diagram showing how slits are formed in the substrate. As shown in Fig. 19, substrate 13 is cut with a laser to form slits 13a in substrate 13. Fig. 20 is a diagram showing a state in which slits have been formed in the substrate. As shown in Fig. 20, dummy slits 13Ac are also formed in substrate 13 with a laser, and the electronic device 10A shown in Fig. 4 is formed.

[0051] [Method of manufacturing electronic components and contact lens type electronic devices] A method for manufacturing the electronic component 20 and the contact lens type electronic device 30 using the electronic device 10A will be described below.

[0052] Fig. 21 is a diagram showing a silicone mold. As shown in Fig. 21, a pair of silicone molds having spherical curved surfaces coated with silicone elastomer are prepared.

[0053] Fig. 22 is a diagram showing how an electronic device is placed on the silicone elastomer. As shown in Fig. 22, the electronic device 10A is placed on the silicone elastomer applied to the lower silicone mold.

[0054] Fig. 23 is a diagram showing the electronic device encapsulated in silicone elastomer. As shown in Fig. 23, the electronic device 10A is encapsulated in silicone elastomer 21 using a silicone mold (step S4). As a result, the electronic component 20 is manufactured.

[0055] Thereafter, the electronic component 20 is sandwiched and sealed from both sides with lens substrates 31 (step S5), thereby completing the manufacture of the contact lens type electronic device 30. [Explanation of symbols]

[0056] 10, 10A electronic equipment 11 Devices 12 Wiring 13, 100, 200 boards 13a, 100a, 200a slit 13b Hollow part 13Ac Dummy slit 14 Device Area 20 Electronic Components 21 Silicone elastomer 30 Contact lens type electronic device 31 Lens substrate

Claims

1. Multiple devices and Wiring electrically connecting each of the plurality of devices; a substrate on which the wiring is formed and on which a slit is formed; Equipped with the substrate is a hollow disk curved into a spherical shape; The electronic device is characterized in that the slits are formed in concentric circles that overlap each other when projected in a direction away from the apex of the spherical surface.

2. 2. The electronic device according to claim 1, wherein the substrate is bent so as to conform to a predetermined curved surface.

3. 3. The electronic device according to claim 2, wherein the slit is formed so as to extend in a direction substantially perpendicular to a gradient vector of each point on the predetermined curved surface with respect to a predetermined direction.

4. 4. The electronic device according to claim 3, wherein the slit is formed so as to extend in a direction substantially perpendicular to the gradient vector at a position where the magnitude of the gradient vector is large.

5. 5. The electronic device according to claim 3, wherein the substrate is formed with a plurality of slits each having a parallel curved line.

6. 5. The electronic device according to claim 2, wherein the wiring is formed so as to extend in a direction substantially perpendicular to a gradient vector of each point on the predetermined curved surface with respect to a predetermined direction.

7. 7. The electronic device according to claim 6, wherein the wiring is formed so as to extend in a direction substantially perpendicular to the gradient vector at a position where the magnitude of the gradient vector is large.

8. The electronic device according to any one of claims 1 to 7, characterized in that the substrate is provided with dummy slits formed in an area where the wiring is not formed, and which are formed in a concentric shape so as to overlap each other when projected in a direction away from the apex of the sphere.

9. The electronic device as described in claim 1, characterized in that the substrate is provided with a reinforcing portion extending in a direction away from the apex of the spherical surface.

10. The electronic device according to claim 9 , wherein the devices are arranged at substantially equal intervals so that the devices have equal central angles with respect to the center of the disk.

11. 11. An electronic component comprising the electronic device according to claim 1 encapsulated in a silicone elastomer.

12. A contact lens type electronic device, comprising: the electronic component according to claim 11, sandwiched between lens substrates and sealed therewith.

13. A process for forming wiring on a substrate which is a hollow disk; electrically connecting a plurality of devices to the wiring and mounting the devices on the substrate; forming concentric slits on the substrate so as to overlap each other when projected in a direction away from the center of the disk; A method for manufacturing an electronic device, comprising:

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