Electric component and reinforcing plate

Abstract

To provide an electric component which dispenses with punching processing and enables formation of a complicated three-dimensional shape, in a reinforcing plate, and a reinforcing plate.SOLUTION: An electric component 10 includes a flexible printed wiring board (FPC 100) and reinforcing plates (first reinforcing plate 310 and second reinforcing plate 320) bonded to the FPC 100, wherein the first reinforcing plate 310 and the second reinforcing plate 320 are composed of a molded article which has such heat resistance as to endure a reflow soldering step, and is composed of a thermoplastic resin.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electrical component including a flexible printed wiring board, and a reinforcing plate. [Background technology]

[0002] In electrical equipment equipped with flexible printed circuit boards (hereinafter referred to as "FPCs"), a technique is known in which various electronic components and connectors are attached to the FPC by reflow soldering. Because the FPC itself is highly flexible, a stiffening plate is generally attached to the backside of the FPC where the various electronic components and connectors are attached. Glass epoxy material, which has excellent heat resistance, is widely used as the material for the stiffening plate.

[0003] Glass epoxy reinforcing plates are generally manufactured into the desired shape by die-punching before or after bonding to the FPC. This type of punching process can result in large burrs in the cut area, and there are concerns that the resulting cutting powder can have a negative impact on electrical components. Another drawback of glass epoxy reinforcing plates is that they are difficult to process in the thickness direction, making it difficult to form complex three-dimensional shapes. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3895125 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an electrical component and a reinforcing plate that can be formed into a complex three-dimensional shape without requiring punching. [Means for solving the problem]

[0006] The present invention employs the following means to solve the above problems.

[0007] That is, the electrical equipment of the present invention is A flexible printed wiring board; a reinforcing plate attached to the flexible printed wiring board; An electrical component comprising: The reinforcing plate is characterized by having heat resistance sufficient to withstand a reflow soldering process and being made of a molded product made of thermoplastic resin.

[0008] The reinforcing plate of the present invention is A reinforcing plate to be attached to a flexible printed wiring board, It is characterized by having heat resistance that can withstand the reflow soldering process and being made of a molded product made of thermoplastic resin.

[0009] According to these inventions, the reinforcing plate is formed from a molded product made of thermoplastic resin, eliminating the need for punching and allowing for complex three-dimensional shapes. Furthermore, the reinforcing plate has heat resistance that can withstand the reflow soldering process, so that various electronic components, connectors, etc. can be attached by reflow soldering after the reinforcing plate is attached to the flexible printed wiring board without causing any problems.

[0010] The surface of the reinforcing plate that is bonded to the flexible printed wiring board preferably has an arithmetic mean roughness Ra of 5 μm or more.

[0011] This allows the reinforcing plate to be attached to the flexible printed wiring board in a suitable manner.

[0012] The bonding surface of the reinforcing plate that is bonded to the flexible printed wiring board may be provided with a groove that can collect the flowing thermosetting adhesive when the thermosetting adhesive for bonding the reinforcing plate and the flexible printed wiring board flows.

[0013] This prevents the flowing thermosetting adhesive from spilling out of the gap between the flexible printed wiring board and the reinforcing plate when the reinforcing plate is attached to the flexible printed wiring board. It is difficult to form such a groove in a glass epoxy reinforcing plate. By contrast, by using a reinforcing plate made of a molded product made of thermoplastic resin, it is possible to form such a groove.

[0014] The flexible printed wiring board further includes a mounting member, The reinforcing plate may be provided with an engaged portion configured by forming a step in the thickness direction, and the mounting member may be provided with an engaging protrusion that engages with the engaged portion.

[0015] This allows the mounting member to be attached to the flexible printed wiring simply by engaging the engaging protrusions on the mounting member with the engaged portions on the reinforcing plate. It is difficult to create the above-described step in the case of a glass epoxy reinforcing plate, so fasteners such as bolts and nuts are required when attaching a mounting member to a flexible printed wiring board using a reinforcing plate. In contrast, by using a reinforcing plate made of a molded product made of thermoplastic resin, it is possible to create the above-described step, and by using this step as the engaged portion, the mounting component can be easily attached.

[0016] The above configurations may be combined as much as possible. [Effects of the Invention]

[0017] As described above, according to the present invention, it is possible to form a complex three-dimensional shape for the reinforcing plate without the need for punching. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram of an electrical component according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a reinforcing plate according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram of a reinforcing plate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following detailed description of the present invention will be given by way of example with reference to the accompanying drawings, although the dimensions, materials, shapes, relative positions, etc. of the components described in the examples are not intended to limit the scope of the present invention unless otherwise specified.

[0020] (Example) An electrical component and a reinforcing plate according to an embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a schematic diagram of the electrical component according to the embodiment of the present invention, where (a) is a plan view, (b) is a side view, and (c) is a bottom view. In Figure 1, the components inside or on the back side are shown as see-through, with dotted lines drawn. 2 is a schematic diagram of a reinforcing plate according to an embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view (cross-sectional view taken along line AA in (a)). FIG. 3 is a schematic diagram showing a portion of a reinforcing plate according to an embodiment of the present invention, where (a) is a plan view, (b) is a bottom view, and (c) is a cross-sectional view (cross-sectional view taken along line BB in (a)). In these figures, the dimensional relationships between the components (particularly the dimensional relationships in the thickness direction) differ from those of a typical actual product in order to make the configuration of each component easier to understand.

[0021] <Electrical equipment> The electrical equipment 10 according to this embodiment includes a flexible printed circuit board (hereinafter referred to as "FPC100"), electronic components 211 and 212 mounted on the surface of the FPC 100, and a connector 221 and a connector cover 222 attached to the end of the FPC 100. The electrical equipment 10 also includes a first reinforcing plate 310 provided on the back surface of the FPC 100 in an area where the electronic components 211 and 212 are arranged, and a second reinforcing plate 320 provided on the back surface of the FPC 100 in an area where the connector 221 is arranged.

[0022] In the electrical equipment 10 configured as described above, the FPC 100 is first produced. Since the FPC 100 is a known technique, it will be briefly described here. First, a desired circuit is formed by etching a metal foil (such as copper foil) provided on the surface of a base film. After that, a cover film is provided to cover the circuit, and the FPC 100 is obtained by cutting it into a desired shape. A first reinforcing plate 310 and a second reinforcing plate 320 are attached to the FPC 100 obtained in this manner using a thermosetting adhesive.

[0023] Then, electronic components 211, 212 and connector 221 are mounted on the surface of FPC 100. More specifically, a portion of the circuit is exposed through an opening provided in the cover film, and the current-carrying portions of electronic components 211, 212 and connector 221 are connected to the circuit by reflow soldering (soldering in a reflow furnace). This reflow process allows electronic components 211, 212 and connector 221 to be mounted simultaneously. Thereafter, connector cover 222 is attached, and electrical equipment 10 is obtained.

[0024] <Reinforcing plate> The reinforcing plates (first reinforcing plate 310 and second reinforcing plate 320) are heat-resistant enough to withstand the reflow soldering process and are formed from molded thermoplastic resin. An example of a thermoplastic resin that is heat-resistant enough to withstand the reflow soldering process is polyphthalamide (PPA). Note that reflow soldering involves heating at, for example, 260°C, so the material used for the reinforcing plates must be heat-resistant to even higher temperatures. In the case of polyphthalamide, it has heat resistance of 280°C or higher, so it can withstand the heat even in the reflow soldering process.

[0025] As described above, the first reinforcing plate 310 and the second reinforcing plate 320 according to this embodiment are molded from thermoplastic resin, allowing for free design of their planar shapes and ensuring a certain degree of freedom in design in the thickness direction as well. As described above, the first reinforcing plate 310 and the second reinforcing plate 320 are attached to the FPC 100 with a thermosetting adhesive. In this embodiment, the arithmetic mean roughness Ra of the surfaces of the first reinforcing plate 310 and the second reinforcing plate 320 that are bonded to the FPC 100 is configured to be 5 μm or greater. For example, the arithmetic mean roughness of a desired portion of the reinforcing plate can be made Ra5 μm or greater by applying a textured finish, such as etching, to the surface of the mold that forms the reinforcing plate (the mold surface that forms the cavity).

[0026] <<First reinforcing plate>> The first reinforcing plate 310 will be described in more detail with reference to FIG. 2. A groove 311 is provided on the surface of the first reinforcing plate 310 that is bonded to the FPC 100, along the contour of the first reinforcing plate 310 and at a position slightly away from the outer periphery. This groove 311 is provided to collect the flowing thermosetting adhesive 400 that bonds the first reinforcing plate 310 and the FPC 100. That is, when bonding the first reinforcing plate 310 to the FPC 100, the thermosetting adhesive 400 is first applied to the portion of the FPC 100 where the first reinforcing plate 310 is to be bonded. Then, with the first reinforcing plate 310 positioned relative to the FPC 100, the FPC 100 and the first reinforcing plate 310 are heated and pressurized so as to sandwich the thermosetting adhesive 400 between them. As a result, the thermosetting adhesive 400 becomes fluid and then hardens, thereby adhering and bonding the first reinforcing plate 310 to the FPC 100. In this way, during the process of bonding the first reinforcing plate 310 to the FPC 100, the thermosetting adhesive 400 becomes fluid and flows in a manner that spreads outward. This may cause a portion of the thermosetting adhesive 400 to spill out of the gap S between the FPC 100 and the first reinforcing plate 310. However, in this embodiment, the thermosetting adhesive 400 that flows in a manner that spreads outward is collected in the groove 311, thereby preventing a portion of the thermosetting adhesive 400 from spilling out of the gap S between the FPC 100 and the first reinforcing plate 310.

[0027] <<Second reinforcing plate>> The second reinforcing plate 320 will be described in more detail with reference to FIGS. 1 and 3. As described above, the electrical equipment 10 according to this embodiment is provided with a connector cover 222 as an attachment member attached to the FPC 100. The second reinforcing plate 320 is provided with an engaged portion 321 configured by forming a step in the thickness direction, and the connector cover 222 is provided with an engaging protrusion 222a that engages with the engaged portion 321. In FIG. 3(c), the engaging protrusion 222a is shown by a dotted line in a state engaged with the engaged portion 321. In this way, in this embodiment, the connector cover 222 can be easily attached to the FPC 100 simply by engaging the engaging protrusion 222a with the engaged portion 321.

[0028] Although not specifically shown, it is desirable to provide second reinforcing plate 320 with grooves that can collect the flowed thermosetting adhesive, similar to first reinforcing plate 310.

[0029] <Advantages of the electrical equipment and reinforcing plate according to this embodiment> According to this embodiment, the reinforcing plates (first reinforcing plate 310 and second reinforcing plate 320) are formed from molded products made of thermoplastic resin. Therefore, punching is not required when manufacturing the reinforcing plates, and complex three-dimensional shapes can be formed. Furthermore, since the reinforcing plates have heat resistance that can withstand the reflow soldering process, there is no problem even if electronic components 211, 212 and connector 221 are attached by reflow soldering after the reinforcing plates are attached to FPC 100. Note that while this embodiment illustrates the case where electronic components 211, 212 and connector 221 are mounted on FPC 100, it goes without saying that there is no problem even if other mounted components are attached by reflow soldering.

[0030] The arithmetic mean roughness Ra of the surface of the reinforcing plate according to this embodiment that is bonded to the FPC 100 is set to 5 μm or more, which allows the surface area to be sufficiently large and ensures sufficient adhesive strength with the thermosetting adhesive 400, allowing the reinforcing plate to be suitably bonded to the FPC 100.

[0031] Furthermore, grooves 311 capable of collecting the flowed thermosetting adhesive 400 are provided on the surface of the first reinforcing plate 310 that is bonded to the FPC 100. This prevents the flowed thermosetting adhesive 400 from spilling out of the gap S between the FPC 100 and the first reinforcing plate 310 when the first reinforcing plate 310 is bonded to the FPC 100. By providing a similar groove in the second reinforcing plate 320, it is possible to prevent the flowing thermosetting adhesive from spilling out of the gap between the FPC 100 and the second reinforcing plate 320.

[0032] Furthermore, second reinforcing plate 320 is provided with engaged portions 321 configured by forming steps in the thickness direction, and connector cover 222 is provided with engaging protrusions 222a that engage with engaged portions 321. This allows connector cover 222 to be easily attached to FPC 100 simply by engaging engaging protrusions 222a with engaged portions 321. Note that while this embodiment has shown a connector cover as an example of an attachment member, other attachment members can also be easily attached to FPC 100 by employing a similar configuration. [Explanation of symbols]

[0033] 10: Electrical equipment 100:FPC 211, 212: Electronic parts 221: Connector 222: Connector cover 222a engaging protrusion 310: First reinforcing plate 311: Groove 320: Second reinforcement plate 321: Engaged part 400: Thermosetting adhesive S: Gap

Claims

1. A flexible printed wiring board; a reinforcing plate attached to the flexible printed wiring board; An electrical component comprising: The electrical component is characterized in that the reinforcing plate has heat resistance sufficient to withstand a reflow soldering process and is formed from a molded product made of thermoplastic resin.

2. 2. The electrical equipment according to claim 1, wherein the arithmetic mean roughness Ra of the surface of the reinforcing plate that is bonded to the flexible printed wiring board is 5 [mu]m or more.

3. The electrical equipment described in claim 1 or 2, characterized in that the bonding surface of the reinforcing plate to the flexible printed wiring board is provided with a groove that can collect the flowing thermosetting adhesive when the thermosetting adhesive for bonding the reinforcing plate and the flexible printed wiring board flows.

4. a mounting member that is attached to the flexible printed wiring board; The electrical equipment according to claim 1 or 2, characterized in that the reinforcing plate has an engaged portion formed by forming a step in the thickness direction, and the mounting member has an engaging protrusion that engages with the engaged portion.

5. A reinforcing plate to be attached to a flexible printed wiring board, A reinforcing plate characterized by having heat resistance sufficient to withstand a reflow soldering process and being formed from a molded product made of a thermoplastic resin.

6. 6. The reinforcing plate according to claim 5, wherein the arithmetic mean roughness Ra of the surface to be bonded to the flexible printed wiring board is 5 [mu]m or more.

7. The reinforcing plate according to claim 5 or 6, characterized in that the bonding surface to the flexible printed wiring board has a groove that can collect the flowing thermosetting adhesive when the thermosetting adhesive for bonding to the flexible printed wiring board flows.

8. A reinforcing plate as described in claim 5 or 6, characterized in that it is configured by forming a step in the thickness direction and has an engaging portion that engages with an engaging protrusion provided on an mounting member attached to the flexible printed wiring board.

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