Panel and production method

Abstract

This panel comprises: an insulative film; a molded resin that is formed integrally with the insulative film by injection molding; an electric circuit provided to the rear surface of the insulative film; and a flexible wiring substrate that has, at one end thereof, a connection part to be connected to a connection terminal of the electric circuit, and that is passed through the interior of the molded resin and is drawn outside from the back surface of the molded resin. The flexible wiring substrate has both surfaces thereof coated with an adhesive resin.

Description

Panel and manufacturing method

[0001] The present invention relates to a panel and a manufacturing method.

[0002] For example, Patent Document 1 below discloses a technique in which a molded body is formed by injection molding, and a circuit film is integrally molded onto one main surface of the molded body.

[0003] Japanese Patent Application Laid-Open No. 2021-068755

[0004] However, in the technology disclosed in Patent Document 1, wiring is arranged between the molded body and the circuit film, which can result in gaps between the molded body and the circuit film, which can lead to water seeping into the gaps or appearing as different shades of color on the outside, which can result in a decrease in quality.

[0005] Furthermore, the technology disclosed in Patent Document 1 requires the injection of molten resin into the mold twice, to fill the first area in the mold with molten resin and to fill the second area in the mold with molten resin, which complicates the device configuration and manufacturing process, and may result in areas not filled with molten resin and increase the time and cost involved in manufacturing.

[0006] A panel according to one embodiment comprises an insulating film, a molded resin formed integrally with the insulating film by injection molding, an electrical circuit provided on the back surface of the insulating film, and a flexible wiring board having a connection portion at one end that is connected to a connection terminal of the electrical circuit, which passes through the molded resin and is pulled out to the outside from the back surface of the molded resin, and both sides of the flexible wiring board are coated with adhesive resin.

[0007] According to one embodiment, high quality panels can be manufactured at low cost and in a short time.

[0008] FIG. 1 is a diagram schematically showing a laminated structure of a panel according to an embodiment; FIG. 2 is a diagram schematically showing a method for manufacturing a panel according to an embodiment; FIG. 3 is a diagram schematically showing a method for manufacturing a panel according to an embodiment; FIG. 4 is a diagram schematically showing a method for manufacturing a panel according to an embodiment; FIG. 5 is a diagram schematically showing a method for manufacturing a panel according to an embodiment;

[0009] Hereinafter, an embodiment will be described with reference to the drawings.

[0010] 1 is a diagram schematically illustrating the layered structure of a panel 100 according to one embodiment. As shown in FIG. 1, the panel 100 includes a decorative film 110, an FPC 130, a molding resin 140, an adhesive member 150, and a protective member 160.

[0011] The decorative film 110 is provided on the surface of the panel 100 so as to cover the entire surface of the panel 100, thereby decorating the surface of the panel 100. The surface 110A of the decorative film 110 is the operation surface 100A on which a proximity operation is performed by an operating object. The decorative film 110 has a base film 111, a decorative layer 112, and an electrostatic sensor 113.

[0012] The base film 111 is a transparent film-like member. The base film 111 is an example of an "insulating film." For example, the base film 111 is formed using a transparent film-like member that is flexible and insulating (e.g., PMMA (Poly Methyl Methacrylate), PC (Polycarbonate), urethane, ABS, etc.).

[0013] The decorative layer 112 represents a decorative pattern (e.g., a wood grain pattern, a metal pattern, etc.) presented on the surface of the panel 100 (i.e., the operation surface 100A). The decorative layer 112 is provided over the entire rear surface of the base film 111. For example, the decorative layer 112 is formed by printing a plurality of color inks (e.g., CMYK) on the rear surface of the base film 111 in pixel units according to the pattern presented on the surface of the panel 100.

[0014] The electrostatic sensor 113 is provided on the back surface 112A of the decorative layer 112 (the surface facing the molded resin 140). The electrostatic sensor 113 is an example of an "electrical circuit." The electrostatic sensor 113 has a thin film shape. The electrostatic sensor 113 can detect a proximity operation by an operating object by changing its capacitance depending on the proximity distance of the operating object to the operation surface 100A. The electrostatic sensor 113 has a connection terminal 113B on the main surface 113A facing the molded resin 140. For example, the electrostatic sensor 113 is formed by printing on the back surface 112A of the decorative layer 112 by screen printing. Note that, because the electrostatic sensor 113 is provided integrally with the decorative film 110, alignment during injection molding is not required.

[0015] The FPC 130 is an example of a "flexible wiring board" and is a flexible sheet-like or strip-like wiring board. The FPC 130 has a connection portion 131 at one end. The FPC 130 is physically and electrically connected to the connection terminal 113B of the electrostatic sensor 113 at the connection portion 131 by a conductive adhesive. A portion of one end of the FPC 130 is embedded in the molded resin 140 by injection molding the molded resin 140. Furthermore, a portion of the other end of the FPC 130 is drawn out to the outside of the molded resin 140 from a drawing opening 140B provided on a back surface 140A of the molded resin 140 (the surface opposite the surface facing the decorative film 110).

[0016] The FPC 130 has a first extension portion 132 and a second extension portion 133. The first extension portion 132 is a portion that extends from the connection portion 131 in a direction along the decorative film 110. The second extension portion 133 is a portion that continues from the first extension portion 132 and extends in a direction away from the decorative film 110.

[0017] Both surfaces of the FPC 130 are coated with adhesive resin, thereby forming adhesive resin layers 134 on both surfaces. This allows the panel 100 according to one embodiment to increase the degree of adhesion between the FPC 130 (the portion embedded in the molded resin 140) and the molded resin 140, making it less likely that a gap will form between the FPC 130 (the portion embedded in the molded resin 140) and the molded resin 140.

[0018] The molded resin 140 is a resin member that is formed by injection molding integrally with the rear surface 110B of the decorative film 110. The molded resin 140 is a member that serves as the base of the panel 100, and is formed by injection molding into a predetermined shape depending on the application.

[0019] A back surface 140A of the molded resin 140 (the surface opposite to the surface facing the decorative film 110) is provided with a lead-out opening 140B for leading the FPC 130 out of the molded resin 140. The lead-out opening 140B is sealed by applying a sealant 141 from the outside. The panel 100 according to one embodiment is provided with the sealant 141, thereby preventing water and the like from entering the interior of the molded resin 140 through the lead-out opening 140B.

[0020] The adhesive member 150 is provided between the first extension portion 132 of the FPC 130 and the rear surface 110B of the decorative film 110. The adhesive member 150 adheres the first extension portion 132 of the FPC 130 to the rear surface 110B of the decorative film 110. In other words, the adhesive member 150 serves to fill the gap between the first extension portion 132 of the FPC 130 and the rear surface 110B of the decorative film 110. By including the adhesive member 150, the panel 100 according to one embodiment can make it less likely that a gap will occur between the rear surface 110B of the decorative film 110 and the molded resin 140.

[0021] The protective member 160 is a sheet-like member that covers the connection portion 131 of the FPC 130 in a state in which the connection portion 131 is connected to the connection terminal 113B of the electrostatic sensor 113. For example, a heat-resistant tape is used as the protective member 160. By including the protective member 160, the panel 100 according to one embodiment can protect the connection portion 131 of the FPC 130 from molten resin during injection molding and suppress the effects (such as softening) of heat and pressure on the conductive adhesive that bonds the connection portion 131 of the FPC 130 and the connection terminal 113B of the electrostatic sensor 113.

[0022] [Method of Manufacturing Panel 100] A method of manufacturing the panel 100 according to one embodiment will now be described with reference to Figures 2 to 8. Figures 2 to 8 are diagrams that schematically show the method of manufacturing the panel 100 according to one embodiment.

[0023] 2, the FPC 130 is connected to the decorative film 110 (which is provided with the decorative layer 112 and the electrostatic sensor 113). Specifically, the connection portion 131 provided at one end of the FPC 130 is adhered to the connection terminal 113B provided on the main surface 113A of the electrostatic sensor 113 using a conductive adhesive. Furthermore, the first extension portion 132 of the FPC 130 is adhered to the back surface 110B of the decorative film 110 using an adhesive member 150. Furthermore, a protective member 160 is attached to the connection portion 131 of the FPC 130 so as to cover the connection portion 131 of the FPC 130.

[0024] (Decorative Film Installation Process) Next, as shown in FIG. 3, the decorative film 110 with the FPC 130 connected thereto is installed on the inner wall surface (bottom surface) of the first mold 11 facing the space 11A.

[0025] (Protective Block Installation Process) Next, as shown in FIG. 4 , a columnar protective block 20 is installed in the first mold 11, and the protective block 20 protects the second extension portion 133 of the FPC 130. In this process, the protective block 20 can be separated into a first protective block 20A and a second protective block 20B. With the second extension portion 133 of the FPC 130 positioned in a groove 21 formed in the first protective block 20A, the second protective block 20B can be coupled to the first protective block 20A to close the groove 21, thereby protecting the second extension portion 133 of the FPC 130. The protective block 20 is positioned and fixed in a predetermined position by being fitted into the recess 11B of the first mold 11. In this protective block installation process, the second extension portion 133 of the FPC 130 can be positioned in the protective block 20 without the second mold 12 being fastened to the first mold 11, making it easy to protect the second extension portion 133 of the FPC 130.

[0026] 5, the second mold 12 is fastened to the first mold 11. This forms the cavity 10 that is closed by the first mold 11 and the second mold 12. Note that the second mold 12 has a through hole 12A formed therein, so that the protective block 20 can be fitted into the through hole 12A.

[0027] (Injection process) Next, as shown in FIG. 6 , molten resin is simultaneously injected from two gates 12G1 and 12G2 provided on the second mold 12 into the cavity 10 closed by the first mold 11 and the second mold 12, thereby injection molding the molded resin 140.

[0028] Here, in this injection process, suitable injection conditions (gate position, gate aperture number, gate aperture diameter, injection pressure, etc.) obtained in advance by simulation are used. As a result, in this injection process, the molten resin injected from gate 12G1 (the first surface side of second extension portion 133 of FPC 130) and the molten resin injected from gate 12G2 (the second surface side of second extension portion 133 of FPC 130) can intersect at the position of second extension portion 133 of FPC 130 (i.e., reach second extension portion 133 of FPC 130 at approximately the same time).

[0029] Therefore, in this injection process, pressure can be applied evenly to the first and second surfaces of the second extension portion 133 of the FPC 130 at the same time, which prevents the molten resin from applying a biased pressing force to the second extension portion 133 of the FPC 130, thereby preventing defects such as bending or breaking of the FPC 130.

[0030] Furthermore, in this injection process, the molded resin 140 can be formed by a single injection, which simplifies the device configuration and manufacturing process, thereby suppressing increases in time and costs associated with manufacturing the panel 100.

[0031] Furthermore, in this injection process, since the first extension portion 132 of the FPC 130 is adhered to the back surface 110B of the decorative film 110, it is possible to prevent a gap from occurring between the back surface 110B of the decorative film 110 and the molded resin 140, thereby preventing water from penetrating into the gap or the gap from appearing as a shade of color on the outside.

[0032] Furthermore, in this injection process, the second extension portion 133 of the FPC 130 is protected by the protective block 20 within the through hole 12A of the second mold 12, thereby preventing the second extension portion 133 of the FPC 130 from interfering with the second mold 12.

[0033] Furthermore, in this injection process, since the connection portion 131 of the FPC 130 is protected by the protective member 160, the effects of heat and pressure applied from the molten resin on the conductive adhesive that bonds the connection portion 131 of the FPC 130 and the connection terminal 113B of the electrostatic sensor 113 can be suppressed.

[0034] Furthermore, in this injection process, since adhesive resin layers 134 are formed on both sides of FPC 130, the degree of adhesion between second extension portion 133 (portion embedded in molded resin 140) of FPC 130 and molded resin 140 can be increased by adhesive resin layers 134. Therefore, in this injection process, gaps are less likely to occur between second extension portion 133 (portion embedded in molded resin 140) of FPC 130 and molded resin 140, and intrusion of water into the gaps can be suppressed.

[0035] 7 , the second mold 12 and the protective block 20 are removed, and the panel 100 is then removed from the first mold 11. The removed panel 100 has the decorative film 110 integrally provided on the front surface of the molded resin 140 that has a predetermined outer shape (the same shape as the hollow portion 10 closed by the first mold 11 and the second mold 12), and the FPC 130 is drawn out from a drawing opening 140B on a back surface 140A of the molded resin 140.

[0036] 8, a sealant 141 is applied from the outside to the outlet 140B of the molded resin 140 in the panel 100, thereby sealing the outlet 140B of the molded resin 140. This makes it possible to prevent water from entering the interior of the molded resin 140 from the outlet 140B.

[0037] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0038] This international application claims priority based on Japanese Patent Application No. 2022-131653, filed on August 22, 2022, the entire contents of which are incorporated herein by reference.

[0039] DESCRIPTION OF SYMBOLS 10 Cavity 11 First mold 11A Space 11B Recess 12 Second mold 12A Through hole 12G1, 12G2 Gate 20, 20A, 20B Protective block 100 Panel 100A Operation surface 110 Decorative film 110A Front surface 110B Back surface 111 Base film 112 Decorative layer 112A Back surface 113 Electrostatic sensor 113A Main surface 113B Connection terminal 130 FPC 131 Connection portion 132 First extension portion 133 Second extension portion 134 Adhesive resin layer 140 Molded resin 140A Back surface 140B Pull-out opening 141 Sealant 150 Adhesive member 160 Protective member

Claims

1. An insulating film; a molding resin formed integrally with the insulating film by injection molding; an electric circuit provided on a rear surface of the insulating film; a flexible wiring board having a connection portion at one end thereof to be connected to a connection terminal of the electric circuit, the flexible wiring board passing through the molding resin and being drawn out from the rear surface of the molding resin; Equipped with The flexible wiring board is Adhesive resin layers are formed on both sides A panel characterized by:

2. The panel according to claim 1 , further comprising a protective member for covering the connection portion of the flexible wiring board.

3. The flexible wiring board is a first extension portion extending from the connection portion in a direction along the insulating film; a second extension portion extending in a direction away from the insulating film, the second extension portion being continuous with the first extension portion; The flexible wiring board includes an adhesive member that adheres the first extension portion to the insulating film.

2. The panel according to claim 1 .

4. The molding resin is The flexible wiring board has an outlet on the rear surface, through which the flexible wiring board is drawn out. The outlet port is Sealed from the outside with a sealant 2. The panel according to claim 1 .

5. A method for manufacturing a panel, comprising the steps of: a decorative film setting process for setting the insulating film to which the flexible wiring board is connected in a space of the first mold; a protection block installation step of installing a protection block for protecting the flexible wiring board; a fastening step of fastening a second mold to the first mold; an injection step of injecting a molten resin into the space of the first mold to injection mold a molding resin; Including, In the injection step, molten resin injected from a first surface side of the flexible wiring board; The molten resin injected from the second surface side of the flexible wiring board and the molten resin injected from the second surface side of the flexible wiring board reach the flexible wiring board at approximately the same time. A manufacturing method comprising the steps of:

6. The flexible wiring board is Adhesive resin layers are formed on both sides The method according to claim 5 .

7. The panel includes a protective member for covering a connection portion that is to be connected to a connection terminal of an electric circuit in the flexible wiring board. The method according to claim 5 .

8. The flexible wiring board is a first extension portion extending from a connection portion to be connected to a connection terminal of an electric circuit in a direction along the insulating film; a second extension portion extending in a direction away from the insulating film, the second extension portion being continuous with the first extension portion; The panel comprises: The flexible wiring board includes an adhesive member that adheres the first extension portion to the insulating film. The method according to claim 5 .

9. The molding resin is The flexible wiring board has a pull-out opening on a rear surface thereof, The outlet port is Sealed from the outside with a sealant The method according to claim 5 .