Manufacturing 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

Technical Field

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

Background Art

[0002] For example, Patent Document 1 below discloses a technique of integrally molding a circuit film on one main surface of a molded body by molding the molded body by injection molding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique disclosed in Patent Document 1, since wiring is arranged between the molded body and the circuit film, a gap is generated between the molded body and the circuit film, and there is a risk that water may penetrate into the gap, or the gap may appear as a shade of color in the appearance, resulting in a deterioration in quality.

[0005] In addition, in the technique disclosed in Patent Document 1, in order to fill the molten resin into the first area in the mold and fill the molten resin into the second area in the mold, it is necessary to inject the molten resin into the mold twice. Therefore, the device configuration and the manufacturing process become complicated, and there is a risk that unfilled portions of the molten resin may occur, or the time and cost involved in manufacturing may increase.

Means for Solving the Problems

[0006] A panel according to one embodiment comprises an insulating film, a molded resin integrally formed 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 connected to a connection terminal of the electrical circuit, which passes through the molded resin and is drawn out from the back surface of the molded resin to the outside, wherein the flexible wiring board is coated on both sides with adhesive resin. [Effects of the Invention]

[0007] According to one embodiment, high-quality panels can be manufactured at low cost and in a short time. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic diagram showing the laminated structure of a panel according to one embodiment. [Figure 2] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 3] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 4] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 5] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 6] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 7] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Figure 8] A schematic diagram showing a method for manufacturing a panel according to one embodiment. [Modes for carrying out the invention]

[0009] An embodiment will be described below with reference to the drawings.

[0010] [Composition of Panel 100] Figure 1 is a schematic diagram showing the laminated structure of a panel 100 according to one embodiment. As shown in Figure 1, the panel 100 comprises a decorative film 110, an FPC 130, a molded 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 operating surface 100A to which proximity operation by an operating body is performed. 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 component. The base film 111 is an example of an "insulating film". For example, the base film 111 is formed using a transparent film-like component that has flexibility and insulating properties (e.g., PMMA (Poly Methyl Methacrylate), PC (Polycarbonate), urethane, ABS, etc.).

[0013] The decorative layer 112 represents a decorative pattern (e.g., wood grain pattern, metallic pattern, etc.) presented on the surface of the panel 100 (i.e., the operating surface 100A). The decorative layer 112 is provided over the entire back surface of the base film 111. For example, the decorative layer 112 is formed by printing multiple color inks (e.g., CMYK) on a pixel-by-pixel basis onto the back surface of the base film 111, according to the pattern presented on the surface of the panel 100.

[0014] The electrostatic sensor 113 is provided on the back surface 112A (the surface facing the molded resin 140) of the decorative layer 112. The electrostatic sensor 113 is an example of an "electrical circuit". The electrostatic sensor 113 has a thin film structure. The electrostatic sensor 113 can detect proximity operation by an operating body by changing its capacitance according to the proximity distance of the operating body to the operating 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 screen printing on the back surface 112A of the decorative layer 112. Since the electrostatic sensor 113 is integrally provided with the decorative film 110, alignment during injection molding is unnecessary.

[0015] FPC130 is an example of a "flexible wiring board," and is a flexible sheet-like and strip-like wiring board. FPC130 has a connection portion 131 at one end. At the connection portion 131, FPC130 is physically and electrically connected to the connection terminal 113B of the electrostatic sensor 113 by a conductive adhesive. When the molding resin 140 is injection molded, a portion of one end of FPC130 is embedded in the molding resin 140. When the molding resin 140 is injection molded, a portion of the other end of FPC130 is pulled out from the molding resin 140 through an outlet 140B provided on the back surface 140A of the molding resin 140 (the surface opposite to 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 connecting portion 131 in a direction along the decorative film 110. The second extension portion 133 is a portion that follows the first extension portion 132 and extends away from the decorative film 110.

[0017] Note that the FPC 130 has adhesive resin layers 134 formed on both sides by coating adhesive resin on both sides. Thereby, the panel 100 according to one embodiment can enhance the adhesion between the FPC 130 (the portion embedded in the molding resin 140) and the molding resin 140, and can make it difficult to generate a gap between the FPC 130 (the portion embedded in the molding resin 140) and the molding resin 140.

[0018] The molding resin 140 is a resin member integrally formed with the back surface 110B of the decorative film 110 by injection molding. The molding resin 140 is a member serving as the base of the panel 100, and is formed into a predetermined shape according to the application by injection molding.

[0019] On the back surface 140A of the molding resin 140 (the surface opposite to the surface facing the decorative film 110), a lead-out port 140B for pulling out the FPC 130 to the outside of the molding resin 140 is provided. Note that the lead-out port 140B is sealed by applying a sealant 141 from the outside. The panel 100 according to one embodiment can suppress the intrusion of water or the like from the lead-out port 140B into the inside of the molding resin 140 by including the sealant 141.

[0020] The adhesive member 150 is provided between the first extended portion 132 of the FPC 130 and the back surface 110B of the decorative film 110. The adhesive member 150 adheres the first extended portion 132 of the FPC 130 to the back surface 110B of the decorative film 110. That is, the adhesive member 150 serves to fill the gap between the first extended portion 132 of the FPC 130 and the back surface 110B of the decorative film 110. The panel 100 according to one embodiment can make it difficult to generate a gap between the back surface 110B of the decorative film 110 and the molding resin 140 by including the adhesive member 150.

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

[0022] [Method for manufacturing panel 100] The manufacturing method of panel 100 according to one embodiment will be described below with reference to Figures 2 to 8. Figures 2 to 8 are schematic diagrams showing the manufacturing method of panel 100 according to one embodiment.

[0023] (FPC connection process) First, as shown in Figure 2, the FPC 130 is connected to the decorative film 110 (which has a decorative layer 112 and an electrostatic sensor 113). Specifically, the connection portion 131 provided at one end of the FPC 130 is bonded to the connection terminal 113B provided on the main surface 113A of the electrostatic sensor 113 using a conductive adhesive. In addition, the first extension portion 132 of the FPC 130 is bonded 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 Figure 3, the decorative film 110, with the FPC 130 attached, is placed on the inner wall surface (back bottom surface) of the first mold 11 facing the space 11A.

[0025] (Protective block installation process) Next, as shown in Figure 4, a columnar protective block 20 is installed in the first mold 11 to protect the second extension portion 133 of the FPC 130. In this process, the protective block 20 is divisible 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 is joined to the first protective block 20A so as 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 a 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 even when the second mold 12 is not fastened to the first mold 11, thus easily protecting the second extension portion 133 of the FPC 130.

[0026] (Fascinating process) Next, as shown in Figure 5, the second mold 12 is fastened to the first mold 11. This forms a cavity 10 that is closed off by the first mold 11 and the second mold 12. Since the second mold 12 has a through hole 12A, the protective block 20 can be fitted into the through hole 12A.

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

[0028] In this injection process, suitable injection conditions (gate position, number of gate openings, gate opening diameter, injection pressure, etc.) determined in advance through simulation are used. This allows the molten resin injected from gate 12G1 (the first surface side of the second extension portion 133 of the FPC 130) and the molten resin injected from gate 12G2 (the second surface side of the second extension portion 133 of the FPC 130) to intersect at the position of the second extension portion 133 of the FPC 130 (i.e., reach the second extension portion 133 of the FPC 130 almost simultaneously).

[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. This suppresses the application of uneven pressure from the molten resin to the second extension portion 133 of the FPC 130, thereby suppressing defects such as breakage and disconnection of the FPC 130.

[0030] Furthermore, since the molded resin 140 can be formed in a single injection in this injection process, the equipment configuration and manufacturing process can be simplified, thereby suppressing increases in the time and cost associated with the manufacturing of the panel 100.

[0031] Furthermore, in this injection molding process, since the first extension portion 132 of the FPC 130 is bonded to the back surface 110B of the decorative film 110, it is possible to make it difficult for a gap to form between the back surface 110B of the decorative film 110 and the molded resin 140, thereby preventing water from entering the gap and preventing the gap from appearing as a difference in color in appearance.

[0032] Furthermore, in this injection molding 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, thus 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 to the connection terminal 113B of the electrostatic sensor 113 can be suppressed.

[0034] Furthermore, in this injection molding process, since adhesive resin layers 134 are formed on both sides of the FPC 130, the degree of adhesion between the second extension portion 133 of the FPC 130 (the portion embedded in the molded resin 140) and the molded resin 140 can be increased by the adhesive resin layers 134. Therefore, in this injection molding process, it is possible to make it difficult for gaps to form between the second extension portion 133 of the FPC 130 (the portion embedded in the molded resin 140) and the molded resin 140, thereby suppressing the intrusion of water into such gaps.

[0035] (Panel removal process) Next, as shown in Figure 7, after removing the second mold 12 and the protective block 20, the panel 100 is removed from the first mold 11. The removed panel 100 has a predetermined outer shape (the same shape as the cavity 10 closed by the first mold 11 and the second mold 12), with a decorative film 110 integrally attached to the front surface of the molded resin 140, and the FPC 130 is pulled out from the pull-out opening 140B on the back surface 140A of the molded resin 140.

[0036] (Sealant application process) Next, as shown in Figure 8, the outlet 140B of the molded resin 140 in the panel 100 is sealed by applying a sealant 141 to the outside of the outlet 140B. This prevents water from entering the inside 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 or changes are possible within the scope of the gist of the present invention as described in the claims.

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

[0039] 10 Cavity 11. First mold 11A Space 11B Recess 12. Second mold 12A through hole 12G1, 12G2 gates 20, 20A, 20B protective blocks 100 panels 100A control panel 110 Decorative film 110A surface 110B back side 111 Base film 112 Decorative layer 112A back side 113 Electrostatic Sensor 113A Main surface 113B Connection terminal 130 FPC 131 Connection part 132 1st extension section 133 2nd extension section 134 Adhesive resin layer 140 Molding resin 140A back 140B Outlet 141 Sealant 150 Adhesive Members 160 Protective component

Claims

1. A method for manufacturing a panel, A decorative film installation step involves placing an insulating film with a flexible wiring board connected to it within the space of the first mold, A protective block installation step, which involves installing a protective block to protect the flexible wiring board, A fastening step of fastening the second mold to the first mold, The injection process involves injecting molten resin into the space of the first mold to injection mold the resin. Includes, In the injection process, Molten resin injected from the first side of the flexible wiring board, Injection conditions are used in which the molten resin injected from the second side of the flexible wiring board reaches the flexible wiring board almost simultaneously. A manufacturing method characterized by the following features.

2. The aforementioned flexible wiring board is Adhesive resin layers are formed on both sides. The manufacturing method according to claim 1, characterized in that it

3. The panel includes a protective member that covers the connection portion connected to the connection terminals of the electrical circuit on the flexible wiring board. The manufacturing method according to claim 1, characterized in that it

4. The aforementioned flexible wiring board is A first extension portion extends in a direction along the insulating film from the connection portion which is connected to the connection terminal of the electrical circuit, The first extended portion is followed by a second extended portion that extends away from the insulating film, The aforementioned panel is The first extended portion of the flexible wiring board is provided with an adhesive member for bonding it to the insulating film. The manufacturing method according to claim 1, characterized in that it

5. The aforementioned molded resin is The flexible wiring board has an outlet on the back from which it is pulled out, The aforementioned drawer opening is, It is sealed from the outside with a sealant. The manufacturing method according to claim 1, characterized in that it

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