Electroconductive sheet and method for manufacturing same, and electroconductive molded article and method for manufacturing same

Abstract

[Problem] Provided is an electroconductive sheet in which the degree of freedom of design is improved. [Solution] An electroconductive sheet (10) comprises a base material sheet (11) having an opening (13), an electroconductive wire (21) fixed to one surface of the base material sheet (11) so as to overlap at least a portion of the opening (13), and an electrode member (12) provided to one surface or the other surface of the base material sheet (11) so as to cover at least a portion of the opening (13), the electroconductive wire (21) being electrically connected to the electrode member (12) at the opening (13).

Description

Conductive sheet and manufacturing method thereof, and conductive molded product and manufacturing method thereof

[0001] The present invention relates to a conductive sheet, and more particularly to a conductive sheet used in a vehicle heater and a method for manufacturing the same.

[0002] A conventional conductive sheet is known that uses heat generated by supplying electricity to a conductive wire as a heater. The conductive sheet includes a conductive wire fixed to a base sheet and an electrode member electrically connected to the conductive wire.

[0003] For example, Patent Document 1 describes a film heater in which conductive wires are embedded in a support sheet by utilizing ultrasonic fusion.

[0004] Patent No. 7121513

[0005] The invention described in Patent Document 1 requires consideration of injection molding conditions, such as the effects of heat and the pressure exerted on the conductive wire when it is attached to another molded product, when electrically connecting the conductive wire and the metal plate, making it difficult to freely design.

[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a conductive sheet with improved design freedom.

[0007] A conductive sheet according to one embodiment of the present invention comprises a base sheet having an opening, a conductive wire fixed to one side of the base sheet so as to overlap at least a portion of the opening, and an electrode member provided on one or the other side of the base sheet so as to cover at least a portion of the opening, wherein the conductive wire is electrically connected to the electrode member at the opening.

[0008] With this configuration, the base sheet has an opening, so the base sheet is not present at the connection between the conductive wire and the electrode member. This allows the conductive wire and the electrode member to be formed on either of the two surfaces of the base sheet, thereby improving design freedom. Furthermore, because the conductive wire and the electrode member are electrically connected through the opening, i.e., the area where the base sheet is not provided, damage to the base sheet due to heat generated during connection can be prevented.

[0009] Preferably, the conductive wire traverses the opening.

[0010] With this configuration, the ends of the conductive wires are not exposed in the openings, which prevents the conductive wires from being misaligned and enables reliable connection between the conductive wires and the electrode members.

[0011] Preferably, the electrode member is provided on one surface of the base sheet so as to cover the conductive wire.

[0012] Preferably, the base sheet has a first region that is covered by the electrode member around the periphery of the opening and a second region that is not covered by the electrode member. The conductive wire has an embedded region that is embedded in one surface of the base sheet in the first region and an exposed region that is exposed from the one surface of the base sheet. A height dimension (t1) of the embedded region of the conductive wire in the first region is the same as or greater than a height dimension (t1') of the embedded region of the conductive wire in the second region.

[0013] By configuring it in this manner, the conductive wire located in the first region adheres more tightly to the base sheet, and the pressure applied to the conductive wire is distributed to the base sheet, thereby preventing the conductive wire from being broken by the electrode member.

[0014] Preferably, the ratio (t1 / t1') of the height dimension (t1) of the buried region in the first region to the height dimension (t1') of the buried region in the second region is 1.1 or more and 1.8 or less.

[0015] This configuration improves the adhesion between the conductive wire and the base sheet in the first region, making it difficult for external pressure to be transmitted to the conductive wire. Furthermore, it is possible to prevent excessive tension from being applied to the conductive wire in the first region, thereby increasing the tolerance for external pressure. This makes it possible to prevent the conductive wire from being broken by the electrode member even when a heavy load is applied, for example, during injection molding.

[0016] Preferably, the electrophotographic device further comprises an adhesive layer that bonds the electrode member and the first region of the base sheet together.

[0017] By configuring it in this manner, the adhesion between the electrode member and the base sheet is increased in the first region, and the pressure applied to the electrode member is distributed throughout the base sheet, thereby preventing the conductive wire from being broken by the electrode member.

[0018] Preferably, in the first region, the thickness dimension (t4) of the adhesive layer is greater than the height dimension (t2) of the exposed region of the conductive wire.

[0019] With this configuration, the conductive wires located in the first region are covered with the adhesive layer, which can prevent the conductive wires from being broken by the electrode member.

[0020] Preferably, the thickness dimension (t4) of the adhesive layer in the first region is 0.1 mm or more and 0.5 mm or less.

[0021] With this configuration, the conductive wires located in the first region can be covered with the adhesive layer, and when heat or pressure is applied to the conductive sheet, the adhesive layer does not protrude from the first region, thereby preventing a weakening of the adhesive strength between the base sheet and the electrode member.

[0022] Preferably, the height dimension (t1) of the conductive wire embedded region in the first region is 50% or more and 90% or less of the height dimension (t3) of the conductive wire.

[0023] By configuring it in this manner, the exposed area of ​​the conductive wire in the first region is reduced, so that when external pressure is applied to the electrode member or the conductive wire, it is possible to prevent the conductive wire from being broken by the electrode member.

[0024] Preferably, the height dimension (t1') of the conductive wire-embedded region in the second region is 40% to 75% of the height dimension (t3') of the conductive wire.

[0025] With this configuration, deformation of the base sheet due to stress from the conductive wires can be suppressed.

[0026] A method for manufacturing a conductive sheet according to one embodiment of the present invention includes the steps of preparing a base sheet having an opening, adhering a conductive wire to one surface of the base sheet so as to overlap at least a portion of the opening, forming an electrode member on one surface of the base sheet so as to cover at least a portion of the opening and the conductive wire, and electrically connecting the electrode member and the conductive wire at the opening using heat or ultrasound.

[0027] A method for manufacturing a conductive sheet according to another aspect of the present invention includes the steps of preparing a base sheet having an opening, forming an electrode member on one or both sides of the base sheet so as to cover at least a portion of the opening, fixing a conductive wire to one side of the base sheet so as to overlap at least a portion of the opening and the electrode member, and electrically connecting the electrode member and the conductive wire at the opening using heat or ultrasound.

[0028] According to this manufacturing method, the conductive wire and the electrode member are connected in the opening, i.e., in the area where the base sheet is not present. This allows the conductive wire and the electrode member to be formed on the desired side of the base sheet. Furthermore, damage to the base sheet due to heat generated when electrically connecting the conductive wire and the electrode member can be prevented.

[0029] A method for manufacturing a resin molded product according to one embodiment of the present invention includes the steps of placing a conductive sheet according to one embodiment of the present invention on one of the cavity surfaces of an injection molding die having a fixed die and a movable die that forms a cavity between the fixed die and the movable die by clamping; clamping the injection molding die; injecting molten resin into the cavity to form a resin molded body while simultaneously adhering a conductive sheet to the surface of the resin molded body; and opening the injection molding die and removing the resin molded body.

[0030] This manufacturing method uses insert molding or in-mold molding, making it possible to manufacture conductive molded products with complex shapes. In addition, the number of manufacturing steps is reduced, making it possible to reduce production costs and time.

[0031] According to the conductive sheet of the present invention, by providing an opening in the base sheet portion that overlaps the connection portion between the conductive wire and the electrode member, the conductive wire and the electrode member can be provided on any desired one of both sides of the base sheet, thereby improving the degree of freedom in design.

[0032] 14 is a plan view showing a schematic configuration of a conductive sheet according to a first embodiment of the present invention; FIG. 14 is a cross-sectional view taken along line II in FIG. 1; FIG. 14 is a cross-sectional view taken along line III in FIG. 1; FIG. 14 is a plan view showing a schematic configuration of a conductive sheet according to a second embodiment of the present invention; FIG. 14 is a cross-sectional view taken along line V in FIG. 4; FIG. 14 is a cross-sectional view taken along line VI in FIG. 4; FIG. 14 is a plan view showing a schematic configuration of a conductive sheet according to a third embodiment of the present invention; FIG. 14 is a cross-sectional view taken along line A' in FIG. 7; FIG. 14 is a cross-sectional view taken along line B' in FIG. 7; (a) to (e) are partially enlarged plan views of openings in other embodiments of the present invention; (a) to (c) are cross-sectional views showing a method for manufacturing a conductive molded article according to an embodiment of the present invention; (a) and (b) are cross-sectional views showing a method for manufacturing a conductive molded article according to other embodiments of the present invention; FIG. 14 is a plan view showing a schematic configuration of a conductive sheet according to a fourth embodiment of the present invention; FIG. 14 is a partially enlarged view of the area indicated by A in FIG. 15A is a cross-sectional view taken along line C' in Fig. 15, (b) is a cross-sectional view taken along line D' in Fig. 15, (c) is a cross-sectional view taken along line E' in Fig. 15, and (d) is a cross-sectional view taken along line F' in Fig. 15. Fig. 15A is a plan view showing a schematic configuration of a conductive sheet in a modified example of the present invention.

[0033] <Regarding the conductive sheet> (First embodiment) Referring to FIG. 1 , a conductive sheet 10 of the first embodiment includes a base sheet 11 having an opening 13, a conductive pattern 20 formed by conductive wires 21 fixed to one surface of the base sheet 11, and an electrode member 12 formed on one surface of the base sheet 11 so as to cover the opening 13.

[0034] The base sheet 11 has a rectangular shape in a plan view and includes one surface 11a and another surface 11b. In this embodiment, conductive wires 21 are embedded in the one surface 11a, and a pattern layer 15 is provided on the other surface 11b.

[0035] The base sheet 11 of this embodiment is formed of a thermoplastic resin, such as a polycarbonate resin, an ethylene resin, a propylene resin, a polyolefin resin, a thermoplastic polyester resin, a polyamide resin, polyvinyl chloride, or an ABS resin. The base sheet 11 may contain two or more of these materials. Furthermore, the base sheet 11 may contain, as appropriate, a dispersant, an antioxidant, a compatibilizer, an ultraviolet stabilizer, an antiblocking agent, an antistatic agent, or the like.

[0036] From the viewpoint of good formability, the thickness of the base sheet 11 is preferably 100 μm or more and 1000 μm or less, more preferably 375 μm or more and 500 μm or less. If it is 100 μm or more, embedding processing of the conductive wire 21 using ultrasonic waves can be easily performed. If it is 375 μm or more, twisting during processing is less likely to occur and handling is excellent. If it is 500 μm or less, molding processing can be easily performed. If it is 1000 μm or more, the conductive sheet becomes more susceptible to cracking, which may make it difficult to mold the resin molded product described below.

[0037] The opening 13 in this embodiment is, for example, rectangular with rounded corners. The size and shape of the opening 13 are not limited as long as it allows the conductive wire 21 to be electrically connected to the electrode member 12 using heat without any problems, and the opening 13 may be rectangular, circular, polygonal, or another shape. A plurality of openings 13 may be formed in the base sheet 11, and the electrode member 12 may be electrically connected to an external electrical circuit through the openings 13. Furthermore, the electrode member 12 may be connected to the outside at a location other than the openings using a conductive adhesive or the like.

[0038] The conductive pattern 20 of this embodiment can have various patterns, such as a zigzag shape or a spiral shape. For example, referring to FIG. 1 , the conductive pattern 20 may be arranged at equal intervals in the short direction. That is, the conductive pattern 20 of this embodiment is a meander-shaped pattern formed in one stroke using a single wire. The conductive pattern 20 is also formed using a single wire, and its end is formed to connect to a conductive member.

[0039] The conductive wires 21 forming the conductive pattern 20 are electrically connected to the electrode members 12 at the openings 13 using heat or ultrasonic waves. The method of "electrically connecting using heat" used here includes, but is not limited to, soldering, resistance welding, thermocompression bonding via anisotropic conductive resin, and the like.

[0040] Furthermore, the conductive wire 21 is connected to the electrode member 12 at the opening 13. The conductive wire 21 and the electrode member 12 are electrically connected at a portion that does not overlap with the base sheet 11 in a plan view, i.e., at the opening 13, so that both members can be formed on either the same side or different sides of the base sheet, improving design freedom. Furthermore, the heat generated when connecting the two members does not directly affect the base sheet 11, and damage to the base sheet 11 due to heat can be suppressed.

[0041] In this embodiment, the conductive wire 21 crosses the opening 13. "Crossing" here means that the conductive wire is arranged so as to pass through any two points on the periphery of the opening. Because the end of the conductive wire 21 is not exposed at the opening 13, misalignment of the conductive wire 21 is suppressed, and the conductive wire 21 and the electrode member 12 can be reliably connected at the opening 13.

[0042] In this embodiment, the conductive wire 21 is a metal wire coated with a black polyurethane-based material and made of an alloy containing copper and silver. However, the material of the metal wire and the color and material of the coating are not limited to this. The metal wire may be made of any material that provides good characteristics such as electrical resistance and is easy to work with during embedding, such as copper or a copper-containing alloy. The coating may be made of any material that provides good insulation and is easy to work with during embedding, such as a polyamideimide-based material. The color of the coating may be any color that makes the conductive wire 21 less noticeable when fixed to the base sheet 11, and may be matched to the color of the base sheet 11 or the pattern layer 15. This makes the conductive wire 21 fixed to the base sheet 11 even less noticeable.

[0043] The diameter of the conductive wire 21 is, for example, 30 μm or more and 300 μm or less, and preferably 50 μm or more and 180 μm or less. If the diameter of the conductive wire 21 is 30 μm or more, good heat generation characteristics can be obtained from the viewpoint of electrical resistance. If the diameter of the conductive wire 21 is 50 μm or more, disconnection due to heat during embedding can be made less likely. If the diameter of the conductive wire 21 is 300 μm or less, embedding processing of the conductive wire 21 becomes easy, and good flexibility can be obtained when forming the conductive pattern 20. If the diameter of the conductive wire 21 is 180 μm or less, the conductive wire 21 becomes less noticeable.

[0044] The electrode member 12 is a plate-shaped member, and its thickness is, for example, 0.05 mm or more and 1.00 mm or less, preferably 0.10 mm or more and 0.30 mm or less. If the thickness of the electrode member 12 is 0.05 mm or more, good rigidity can be ensured for connection with the conductive wire 21, and the electrode member 12 and the conductive wire 21 can be easily connected. If the thickness of the electrode member 12 is 0.10 mm or more, good rigidity and durability can be obtained at the time of connection. If the thickness of the electrode member 12 is 1.00 mm or less, the shape of the electrode member 12 can be prevented from protruding from the surface of the resin molded product or from peeling off during processing or use of the conductive sheet 10. If the thickness of the electrode member 12 is 0.30 mm or less, the effect of the thickness of the electrode member 12 on the overall thickness of the conductive sheet 10 can be reduced, and the conductive sheet 10 can be made thinner.

[0045] The electrode member 12 is electrically connected to an external electric circuit using a known method such as heat, ultrasonic waves, a conductive adhesive, etc. The electrode member 12 may be connected to the outside through the opening 13.

[0046] The electrode member 12 can be made of various materials that provide good heat resistance, electrical resistance, and rigidity, and is selected from conductive materials such as phosphor bronze, aluminum, iron, and copper. Furthermore, the electrode member 12 may be plated with one or more conductive materials selected from silver, tin, nickel, and other materials to facilitate electrical connection with conductive wires. The electrode member 12 of this embodiment is made of phosphor bronze, and the surface of the electrode member 12 is coated with a nickel underplating and a silver plating.

[0047] 2 and 3 , the electrode member 12 of this embodiment is fixed to the base sheet 11 via an adhesive layer 14. The adhesive layer 14 may be made of, for example, a thermosetting resin, an ultraviolet-curing resin, or a pressure-sensitive adhesive, but is not limited to these. The adhesive layer 14 prevents the electrode member 12 from shifting position, thereby ensuring connection between the conductive wire 21 and the electrode member 12 in the opening 13. Furthermore, the conductive sheet 10 of this embodiment can improve waterproofness and dustproofness by adhering the electrode member covering the opening 13 to the opening 13 of the base sheet 11 with the adhesive layer 14.

[0048] In this embodiment, the adhesive layer 14 is provided only in the area where the base sheet 11 is present in a planar view, but it may also be provided so as to cover the area where the base sheet 11 is not present, i.e., a part of the opening 13, and the opening of the adhesive layer 14 does not have to coincide with the opening 13.

[0049] 2 and 3, the base sheet 11 of this embodiment has conductive wires 21 and electrode members 12 provided on one surface, and a design layer 15 provided on the other surface. The design layer 15 is formed by printing, for example, and can represent designs, operation icons, etc.

[0050] Second Embodiment A conductive sheet 10A according to a second embodiment will be described with reference to Figures 4 to 6. The conductive sheet 10A has the same basic configuration as the conductive sheet 10 of the first embodiment, so differences will be described below. The conductive sheet 10 of the first embodiment has an electrode member 12 provided on a conductive wire 21 on one surface of a base sheet 11, whereas the conductive sheet 10A of the second embodiment has a conductive wire 21A provided on an electrode member 12A on one surface of a base sheet 11A.

[0051] 5 and 6, in the conductive sheet 10A of the second embodiment, the conductive wires 21A are not exposed in the openings 13A. This configuration can particularly prevent the conductive wires 21A from peeling off or breaking from the electrode member 12A due to an external impact received on the other surface of the base sheet 11A.

[0052] In the second embodiment, the adhesive layer 14A is provided only in the area where the base sheet 11A is present in a planar view, but it may also be provided so as to cover the area where the base sheet 11A is not present, i.e., part or all of the opening 13A.

[0053] 7 to 9, a conductive sheet 10B according to a third embodiment will be described. The conductive sheet 10B has the same basic configuration as the conductive sheet 10 of the first embodiment, and therefore only differences will be described. The conductive sheet 10B differs in that the conductive wires 21B and the electrode members 12B are provided on different surfaces of the base sheet 11B.

[0054] 8 and 9, in the conductive sheet 10B of the third embodiment, the conductive wire 21B and the electrode member 12B are not in contact with each other except at the opening 13B, which prevents an external impact from being applied intensively to a portion of the conductive wire 21B, and prevents the conductive wire 21B from being broken due to being partially pressed by the electrode member 12B.

[0055] In the third embodiment, the adhesive layer 14B is provided only in the area where the base sheet 11B is present in a planar view, but it may also be provided so as to cover the area where the base sheet 11B is not present, i.e., a part of the opening 13B.

[0056] 10, a configuration in which the conductive wire 10 in each of the above-described embodiments crosses or enters the opening 13 will be described. "Entering" here means that one end of the conductive wire passes through a point on the periphery of the opening and is positioned so as to remain above the opening.

[0057] As shown in Figure 10(a) , the conductive sheet 10 of each of the above embodiments is fixed onto the base sheet 11 so that the conductive wire 21 crosses the opening 13 in a straight line and connects two opposing sides of the rectangular opening 13.

[0058] 10(b) and 10(c), the conductive sheet 10 of each of the above embodiments may be configured such that the conductive wire 21 traverses the opening 13 so as to bend within the opening 13. The conductive wire 21 may be fixed to the base sheet 11 so as to connect any one side or two sides of the rectangular opening 13.

[0059] 10(d), one end of the conductive wire 21 may be provided so as to enter the opening 13, i.e., remain above the opening. In this case, it should be noted that the conductive wire 21 must enter at least a length sufficient to be fixed to the electrode member 12 in the opening 13. In particular, when this is applied to the first embodiment, the number of times the conductive wire 21 is sandwiched between the electrode member 12 and the base sheet 11 is reduced, thereby reducing the possibility of the conductive wire breaking.

[0060] 10( e) and 11, a plurality of conductive wires 21 may cross the opening 13. In other words, the opening 13 in each of the above embodiments may have a plurality of conductive wires 21 crossing thereover. Although two conductive wires are shown in the drawings for convenience, it goes without saying that the number of crossing conductive wires may be three or more. When providing a plurality of conductive wires 21 above the opening, the conductive wires 21 may be patterned so that they do not contact each other, or so that they contact each other at the opening.

[0061] In each of the above embodiments, the conductive wire 21 is fixed to the base sheet 11, but other functional layers, such as a coating layer, may be provided between the conductive wire 21 and the base sheet 11.

[0062] In each of the above embodiments, the pattern layer 15 is provided on the other side of the base sheet 11, but the pattern layer 15 can be provided on any side depending on the design of the product to which the conductive sheet 10 is to be applied.

[0063] Furthermore, although the conductive sheet 10 in each of the above embodiments is provided with the adhesive layer 14, it is not essential that it be provided. If the adhesive layer 14 is not provided, the thickness of the conductive sheet can be made thinner.

[0064] The conductive sheet 10 of each of the above embodiments is typically used as a wire heater for a vehicle, but its use is not particularly limited. The conductive sheet 10 can also be used as, for example, a temperature sensor, a strain sensor, an antenna, etc.

[0065] <Conductive Sheet Manufacturing Method> Next, a method for manufacturing the conductive sheet 10 of the first embodiment will be described. First, a base sheet 11 having openings 13 is prepared. In this step, a roll-shaped base sheet is typically prepared that has been punched in advance to form the openings.

[0066] Next, a conductive wire 21 is fixed to one surface of the base sheet 11 so as to overlap at least a portion of the opening 13. In this step, an ultrasonic welding device is used to fix the conductive wire so as to embed it on the base sheet 11. Next, an electrode member 12 is formed on one surface of the base sheet 11 so as to cover at least a portion of the opening 13 and the conductive wire 21. In this step, an electrode member is prepared and attached to one surface of the base sheet. At this time, an adhesive layer may be prepared as necessary.

[0067] Finally, the electrode member 12 and the conductive wire 21 are electrically connected to each other at the opening 13 using heat or ultrasonic waves. In this process, the connection can be achieved using various techniques, such as soldering, resistance welding, thermocompression bonding via anisotropic conductive resin, ultrasonic welding, etc. This makes it possible to manufacture a conductive sheet in which the conductive wire and the electrode member are securely fixed to one side of the base sheet.

[0068] According to the manufacturing method of the conductive sheet 10 of the first embodiment, the conductive member and the conductive wire can be reliably electrically connected in the openings, so that the conductive wire and the electrode member are electrically connected in the openings, i.e., in the areas where the base sheet is not provided, and therefore damage to the base sheet due to heat generated during the connection can be prevented.

[0069] (Regarding Manufacturing Methods of Other Embodiments) Next, a description will be given of manufacturing methods of conductive sheets 10A and 10B of other embodiments. The manufacturing methods of conductive sheets 10A and 10B of other embodiments are basically the same as the manufacturing method of conductive sheet 10, except that conductive wires are provided after electrode members are provided on a base sheet.

[0070] As shown in Figures 5 and 6, the method for manufacturing a conductive sheet according to this embodiment also allows the conductive wire to be disposed on the electrode member in the opening. Furthermore, as shown in Figures 7 to 9, the conductive wire and the electrode member can also be disposed on different surfaces of the base sheet. This allows the manufacturing method according to this embodiment to form the conductive wire and the electrode member on the desired surface of the base sheet, thereby improving the degree of freedom in design.

[0071] In the manufacturing method of the conductive sheet of each of the above embodiments, the conductive wire 21 is fixed to the base sheet 11 by ultrasonic embedding processing using an ultrasonic welding device. However, the method of fixing the conductive wire 21 is not limited to this. The conductive wire 21 may also be fixed to the base sheet 11 using a heat-resistant adhesive or the like. This eliminates the need for equipment used in ultrasonic embedding processing, thereby reducing the cost of the equipment.

[0072] 12 , if the surface of the conductive sheet 10 on which the pattern layer 15 is provided is defined as the front side, and the surface on which the electrode member 12 and the conductive wire 21 are provided is defined as the back side, the conductive molded product 40 has a configuration in which a resin molded body 41 is laminated on the back side of the conductive sheet 10 of the first embodiment. That is, the electrode member 12 and the conductive wire 21 provided on the back side are covered with the resin molded body 41. This can prevent the electrode member 12 and the conductive wire 21 from peeling off from the base sheet 11, and can improve the durability, waterproofness, and dustproofness of the conductive molded product 40.

[0073] The conductive molded product 40 of this embodiment is provided with a resin molded body 41 on the back surface side of the conductive sheet 10. However, the resin molded body 41 may be provided only on the front surface side of the conductive sheet 10, or may be provided on both surfaces.

[0074] Although the resin molded product 40 of this embodiment includes the conductive sheet 10 and the resin molded body 41, it goes without saying that various layers can be provided depending on the desired design and function. For example, an embossed surface layer may be provided on the upper surface of the resin molded body 41, or an adhesive layer may be provided between the conductive sheet 10 and the resin molded body 41.

[0075] <Method for manufacturing a conductive molded article> (First embodiment) Next, a method for manufacturing a conductive molded article 40 using a conductive sheet 10 will be described with reference to Fig. 12. The method for manufacturing a conductive molded article of this embodiment is characterized in that injection molding and fixing of the conductive sheet to a resin molded body are performed simultaneously.

[0076] 12(a), first, a conductive sheet 10 is placed on one of the cavity surfaces of an injection molding die 42 having a fixed die 44 and a movable die 43 that forms a cavity between the fixed die 44 and the movable die 43 by clamping. In this embodiment, the conductive sheet 10 is placed along the cavity surface of the movable die 43.

[0077] Next, referring to FIG. 12(b), the injection molding die 42 is clamped. Clamping is performed by moving the movable die 43. The fixed die 44 has a resin inlet (not numbered) for pouring molten resin into the cavity, and the molten resin is injected into the cavity formed by clamping. Here, a conductive sheet 10 is provided on the cavity surface on the movable die 43 side. That is, by injecting molten resin into the cavity, a resin molded body 41 is formed and, at the same time, the conductive sheet 10 is fixed to the surface of the resin molded body 41.

[0078] 12(b) and 12(c), the injection molding die 42 is opened to remove the conductive molded article 40 to which the conductive sheet 10 and the resin molded body 41 are fixed. The mold opening is performed by moving the movable die 43.

[0079] The method for manufacturing the conductive molded product 40 according to this embodiment uses insert molding or in-mold molding to simultaneously perform "injection molding" and "bonding of the conductive sheet to the resin molded body," making it possible to manufacture the conductive molded product 40 in a complex shape. Also, the production time can be shortened.

[0080] Another embodiment will now be described with reference to a method for manufacturing a conductive molded article 40 according to another embodiment. The method for manufacturing a conductive molded article according to this embodiment is a manufacturing method in which a preformed conductive sheet 10 and a resin molded body 41 are bonded together.

[0081] 13(a), a preform 10 is prepared by folding a conductive sheet 10 according to one embodiment of the present invention into a desired shape. At the same time, a resin molded body 41 having a shape corresponding to the shape of the preform is prepared. Note that the "shape corresponding to the shape of the preform" mentioned here does not necessarily mean that the resin molded body 41 and the preform 10 have the same shape. Specifically, it is intended to include a design that is completed by combining different corresponding shapes.

[0082] 13(b), a resin molded article 41 is fixed to at least one of the front and back surfaces of the preform 10. In this embodiment, the resin molded article 41 is fixed to the back surface of the preform 10. In this way, a conductive molded article 40 is formed.

[0083] According to the manufacturing method of this embodiment, injection molding is not performed, and therefore, compared to the manufacturing method of the conductive molded article 40 according to Embodiment 1, it is easier to manufacture molds and jigs, and the costs of the molds and jigs can be reduced. In addition, since there are fewer restrictions on molds and jigs, it is easier to produce large products.

[0084] When the resin molded product 41 is fixed to the preform body 10 , an adhesive layer may be provided between the preform body 10 and the resin molded product 41 .

[0085] Fourth Embodiment Next, a conductive sheet 10C according to a fourth embodiment will be described with reference to FIGS.

[0086] 14 , a base sheet 11C according to the fourth embodiment has a first region X1 and a second region X2. The conductive wires 21C have an embedded region and an exposed region. The conductive sheet 10C has the same basic structure as the conductive sheet 10 according to the first embodiment, but is characterized in that the conductive wires are embedded in the base sheet.

[0087] The surface of the base sheet 11C according to the fourth embodiment is divided into a first region X1 that is covered by the electrode member 12C on the periphery of the opening 13C, and a second region X2 that is not covered by the electrode member 12C. That is, the "first region" is the region that is covered by the electrode member 12C on the periphery of the opening, and the "second region" is the region on the surface of the base sheet 11C that is not covered by the electrode member 12C.

[0088] 15 , the electrode member 12C is larger than the opening 13C and is disposed so as to cover the opening 13C. Here, the electrode member 12C is preferably fixed to the base sheet 11C so as to have a width dimension of at least 0.5 mm from the periphery of the opening 13C. In other words, in this embodiment, the electrode member 12C is preferably fixed to the base sheet 11C, and the first region X1 is preferably formed so as to surround the periphery of the opening 13C with a width dimension of 0.5 mm or more. This ensures a sufficient area for fixing the electrode member 12C to the opening 13C. On the other hand, from the viewpoint of external design, the first region X1 preferably has a width dimension of 5.0 mm or less from the periphery of the opening 13C.

[0089] In the fourth embodiment, the conductive wire 21C is embedded in the base sheet 11C using ultrasonic waves while applying pressure or tension to the base sheet 11C. Specifically, an ultrasonic welding device (not shown) melts one surface of the base sheet 11C with ultrasonic waves while feeding out the conductive wire 21C, and then embeds the conductive wire 21C into the one surface of the base sheet 11C while applying pressure to the surface.

[0090] The conductive wire 21C according to the fourth embodiment has an embedded region in the first region where the conductive wire is embedded in one surface of the base sheet 11C, and an exposed region where the conductive wire is exposed from one surface of the base sheet 11C. The "embedded region" here refers to the region where the conductive wire is embedded in the base sheet. The "exposed region" here refers to the region where the conductive wire is exposed from the base sheet.

[0091] (Regarding Dimensions) Next, the dimensions of the conductive sheet according to this embodiment will be described with particular reference to FIG. 15, and FIGS. 16(c) and 16(d).

[0092] In the conductive wire 21C according to the fourth embodiment, the "height dimension t1 of the embedded region in the first region X1" is the same as or greater than the "height dimension t1' of the embedded region in the second region X2." The "height dimension of the embedded region" here refers to the height dimension from one surface of the base sheet as a reference plane to the lower end of the embedded conductive wire. By embedding the conductive wire 21C in the first region X1 as deeply as or deeper than the second region X2, the adhesion between the conductive wire 21C located in the first region X1 and the base sheet 11C is increased, and pressure applied to the conductive wire 21C is dispersed across the base sheet 11C, thereby preventing the conductive wire 21C from being broken by the electrode member 12C.

[0093] The ratio (t1 / t1') of the "height dimension t1 of the conductive wire embedded region in the first region X1" to the "height dimension t1' of the conductive wire embedded region in the second region X2" is preferably 1.0 or more and 1.8 or less, more preferably 1.1 or more and 1.8 or less, and even more preferably 1.1 or more and 1.5 or less. When t1 / t1' is 1.0 or more, the adhesion between the conductive wire 21C and the base sheet 11C in the first region X1 is improved, thereby suppressing breakage of the conductive wire 21C. Furthermore, when t1 / t1' is 1.1 or more, the adhesion between the electrode member 12C and the base sheet 11C is improved, thereby suppressing peeling of the electrode member. Furthermore, when t1 / t1' is 1.8 or less, the embedding depth of the wire gradually changes from the second region X2 to the first region X1, preventing excessive tension from being applied to the wire and suppressing breakage of the conductive wire. If t1 / t1' is 1.5 or less, a conductive sheet with excellent formability can be obtained.

[0094] The "height dimension t1 of the conductive wire embedded region in the first region" is preferably 50% to 90% and more preferably 60% to 80% of the "height dimension t3 of the conductive wire in the first region." The cross-sectional shape of the conductive wire 21C changes slightly due to the pressure and heat applied during embedding. In the present invention, the "height dimension of the conductive wire" refers to the maximum dimension in the height direction in a cross-sectional view after embedding. In the first region X1, if the ratio (t1 / t3) of the "height dimension of the conductive wire embedded region" to the "height dimension of the conductive wire" is 50% or more, the exposed region of the conductive wire 21C in the first region X1 is small, and when external pressure is applied to the electrode member 12C or the conductive wire 21C, breakage of the conductive wire 21C by the electrode member 12C can be suppressed. Furthermore, if t1 / t3 is 60% or more, the difference in height between the surface of the base sheet 11C and the conductive wire 21C is reduced, thereby improving the adhesion between the electrode member 12C and the base sheet 11C and preventing the electrode member from peeling off. Furthermore, if t1 / t3 is 90% or less, the process of embedding the conductive wire 21C into the base sheet 11C can be easily performed. If t1 / t3 is 80% or less, the yield rate can be improved, and productivity can be increased.

[0095] The "height dimension t1' of the conductive wire embedded region in the second region" is preferably 40% to 75% of the "height dimension t3' of the conductive wire in the second region." The conductive wire 21C in the second region X2 forms a pattern on one surface of the base sheet. Therefore, if the conductive wire 21C is embedded too much in the second region X2, the stress of the conductive wire 21C on the base sheet increases, making the base sheet more susceptible to deformation such as warping. In the second region X2, if the ratio (t1' / t3') of the "height dimension of the conductive wire embedded region" to the "height dimension of the conductive wire" is 75% or less, deformation of the base sheet 11C due to the stress of the conductive wire 21C can be suppressed. If the ratio t1' / t3' is 65% or less, a conductive sheet with excellent design and formability can be obtained. Furthermore, if t1' / t3' is 40% or more, the conductive wires 21C can be prevented from peeling off from the base sheet 11C. If t1' / t3' is 50% or more, a conductive sheet with excellent formability can be obtained.

[0096] The adhesive layer 14C according to the fourth embodiment is preferably provided at least in the first region X1 of the base sheet 11C and covers the exposed region of the conductive wire. In other words, the "thickness dimension t4 of the adhesive layer in the first region" is preferably greater than the "height dimension t2 of the exposed region of the conductive wire in the first region." The "height dimension of the exposed region" here refers to the height dimension from one surface of the base sheet as a reference plane to the top end of the conductive wire that is not embedded in the base sheet. In this way, the adhesive layer 14C is interposed between the conductive wire 21C located in the first region X1 and the electrode member 12C, thereby preventing the conductive wire 21C from being broken by the electrode member 12C when external pressure is applied to the electrode member 12C or the conductive wire 21C, for example, during insert molding.

[0097] Furthermore, the "thickness dimension t4 of the adhesive layer in the first region X1" is preferably 0.1 mm or more and 0.5 mm or less. If t4 is 0.1 mm or more, good adhesive strength can be obtained. Furthermore, by setting t4 to 0.1 mm or more, the exposed region of the conductive wire can be covered with the adhesive layer 14, and the adhesive layer 14 can function as a "buffer member" between the conductive wire and the electrode member. If t4 is 0.5 mm or less, it is possible to prevent the adhesive layer from protruding from the first region X1 due to heat or pressure during insert molding, for example, and the thickness of the adhesive layer in the first region X1 from becoming thin.

[0098] The opening 13C is intended to be an opening provided at least in the base sheet 11C. In particular, when the adhesive layer 14C is provided in a sheet form, an opening for fastening the electrode member 12C and the conductive wire 21C needs to be provided in the adhesive layer 14C as well. In this case, the opening in the adhesive layer 14C does not need to coincide with the opening 13C.

[0099] It is difficult to always maintain a constant embedding depth of the conductive wire. Therefore, in the present invention, the dimensions t1, t2, t3, and t4 in the first region X1 were measured at a position 3 mm toward the first region X1 from the position where the conductive wire 21C overlaps with the edge of the opening. Furthermore, the dimensions t1', t2', and t3' in the second region X2 were measured at a position 5 mm toward the second region X2 from the position where the conductive wire 21C overlaps with the edge of the electrode member 12C. If another functional layer is provided on the base sheet and the conductive wire is embedded in that functional layer at each measurement position, the reference plane for each dimension is the functional layer, not the base sheet.

[0100] The size and shape of the electrode member 12C are not particularly limited as long as it can electrically connect the conductive wire 21C to the electrode member 12C at the opening 13C. The electrode member 12C can have various shapes, such as a rectangle, a circle, or a polygon. It is also desirable that at least the portion of the electrode member 12C that contacts the conductive wire 21C be chamfered (chamfered by cutting the edges of the electrode member 12C into an arc shape in cross section, if the electrode member is polygonal, or the circumference of the electrode member 12C into an arc shape in cross section, if the electrode member is circular). This reduces the pressure applied to the conductive wire 21C from the edges of the electrode member 12C, thereby preventing the conductive wire 21C from being broken by the electrode member 12C.

[0101] (Modification) Another modification of the conductive sheet according to one aspect of the present invention will be described with reference to Fig. 17 . A conductive pattern 20D is formed asymmetrically by two conductive wires 21D. An electrode member 12D is provided so as to cover a plurality of openings 13D with one member. Furthermore, an electrode member 12E is provided so as to cover a portion of an opening 13E. In this way, the shape of openings 13D, 13E is not limited to a rectangle, and 12D, 12E may cover at least a portion of one or more openings.

[0102] Example 1 Conductive wires (copper wires, wire diameter 0.11 mm, coating layer 0.01 mm, total diameter 0.12 mm) were embedded in a substrate sheet (Covestro polycarbonate sheet Makrofol UV503, thickness 500 μm) with a 5 mm diameter opening using a Ruhlamat WCE150 wiring drawing device to form a conductive pattern as shown in FIG. 14 . An electrode member (copper plate, length 15 mm × width 15 mm, thickness 0.3 mm) was aligned on the surface of the substrate sheet with the embedded conductive wire so that the center of the electrode member overlapped the center of the opening. The conductive wires and electrode members were connected by soldering at the opening in the substrate sheet.

[0103] Examples 2 to 12, Comparative Examples 1 to 5 Conductive sheets were prepared in the same manner as in Example 1 except for the wire embedding depth.

[0104] (Evaluation of Conductivity After Injection Molding) A resin molded body (polycarbonate resin) was laminated to a thickness of 2 mm by injection molding on the surface of the prepared conductive sheet opposite to the surface on which the electrode member was provided, to prepare a conductive molded product. The electrode member was connected to an external electrode, and the presence or absence of conductivity was confirmed. The wire embedding depth and the results of the conductivity evaluation after injection molding for the examples and comparative examples are shown in Table 1. In Table 1, ○ indicates that conductivity was confirmed, and × indicates that conductivity was not confirmed.

[0105]

[0106] As shown in Table 1, in the conductive sheets of Comparative Examples 1 to 5, no conductivity was confirmed in the molded articles after injection molding, whereas in the conductive sheets of Examples 1 to 12, conductivity was confirmed in the molded articles after injection molding.

[0107] The conductive sheets of Examples 1 to 12 had a t1 / t1' ratio of 1.1 or more and 1.8 or less. By setting t1 / t1' to 1.1 or more, the adhesion between the conductive wire and the base sheet in the first region could be improved, making it difficult for stress during injection molding to be transmitted to the conductive wire. Furthermore, by setting t1 / t1' to 1.8 or less, excessive tension was prevented from being applied to the conductive wire in the first region, and the tolerance for external pressure could be increased. In this way, by embedding the conductive wire deeper in the first region than in the second region, it was possible to prevent the conductive wire from breaking during injection molding.

[0108] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and variations are possible within the scope of the present invention as defined in the claims and within the scope of the details described in the detailed description of the present invention.

[0109] 10 Conductive sheet, 11 Base sheet, 12 Electrode member, 13 Opening, 14 Adhesive layer, 15 Design layer, 20 Conductive pattern, 21 Conductive wire, 40 Conductive molded product, 41 Resin molded body, 42 Injection molding die, 43 Movable die, 44 Fixed die, X1 First region, X2 Second region, t1 Height dimension of embedded region in first region, t2 Height dimension of exposed region in first region, t3 Height dimension of conductive wire in first region, t4 Thickness dimension of adhesive layer in first region, t1' Height dimension of embedded region of conductive wire in second region X2, t3' Height dimension of conductive wire in second region X2

Claims

1. A conductive sheet comprising: a base sheet having an opening; a conductive wire fixed to one side of the base sheet so as to overlap at least a portion of the opening; and an electrode member provided on one or the other side of the base sheet so as to cover at least a portion of the opening, the conductive wire being electrically connected to the electrode member at the opening.

2. The conductive sheet of claim 1, wherein said conductive wire traverses said opening.

3. The conductive sheet according to claim 2, wherein the electrode member is provided so as to cover the conductive wires on one side of the base sheet.

4. A conductive sheet as described in claim 3, wherein the base sheet has a first region that is covered by the electrode member around the periphery of the opening, and a second region that is not covered by the electrode member, the conductive wire has an embedded region that is embedded in one surface of the base sheet in the first region, and an exposed region that is exposed from the one surface of the base sheet, and the height dimension of the embedded region in the first region is the same as or greater than the height dimension of the embedded region in the second region.

5. The conductive sheet according to claim 4, wherein the ratio (t1 / t1') of the height dimension (t1) of the embedded region in the first region to the height dimension (t1') of the embedded region in the second region is 1.1 or greater and 1.8 or less.

6. The conductive sheet according to claim 4, further comprising an adhesive layer that bonds the electrode member and the first region of the base sheet.

7. The conductive sheet according to claim 6, wherein in the first region, a thickness dimension (t4) of the adhesive layer is greater than a height dimension (t2) of the exposed region of the conductive wire.

8. The conductive sheet according to claim 7, wherein the thickness dimension (t4) of the adhesive layer is 0.1 mm or more and 0.5 mm or less.

9. The conductive sheet according to claim 4, wherein a height dimension (t1) of the embedded region of the conductive wire in the first region is 50% or more and 90% or less of a height dimension (t3) of the conductive wire.

10. A conductive sheet as described in claim 4, wherein the height dimension (t1') of the embedded region of the conductive wire in the second region is greater than or equal to 40% and less than or equal to 75% of the height dimension (t3') of the conductive wire.

11. A method for manufacturing a conductive sheet, comprising the steps of: preparing a base sheet having an opening; adhering a conductive wire to one surface of the base sheet so as to overlap at least a portion of the opening; forming an electrode member on one surface of the base sheet so as to cover at least a portion of the opening and the conductive wire; and electrically connecting the electrode member and the conductive wire at the opening using heat.

12. A conductive molded product comprising the conductive sheet according to claim 1 and a resin molded body laminated on the front or back surface of the conductive sheet.

13. A method for manufacturing a conductive sheet, comprising the steps of: preparing a base sheet having an opening; forming an electrode member on one or other side of the base sheet so as to cover at least a portion of the opening; fixing a conductive wire to one side of the base sheet so as to overlap at least a portion of the opening and the electrode member; and electrically connecting the electrode member and the conductive wire at the opening using heat.

14. A method for manufacturing a conductive molded product, comprising the steps of: placing the conductive sheet described in claim 1 on any one of the cavity surfaces of an injection molding die having a fixed die and a movable die that forms a cavity between the fixed die and the movable die by clamping; clamping the injection molding die; injecting molten resin into the cavity to form a resin molded body while simultaneously fixing the conductive sheet to the surface of the resin molded body; and opening the injection molding die and removing the resin molded body.

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