JP4079626B2 - Thin circuit board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thin circuit board.
[0002]
[Prior art]
In recent years, electronic circuits have become highly functional and miniaturized, and for example, in mobile phones and computers, circuits having many functions have been formed in a limited space. For this reason, a device for releasing heat generated from each circuit and a device for reducing the size of the component itself are taken.
[0003]
FIG. 5 shows a configuration of a mobile phone provided with the electronic circuit as described above. A plurality of electronic components 23, an MPU 24, an antenna 25, a speaker 26, and a microphone 27 are mounted on a circuit board 22 fitted in the housing 21, and a signal received by the antenna 25 is processed by the MPU 24 to be electronic. While passing through the component group 23, the electrical signal is converted into an audio signal and output from the speaker 26. The sound signal collected by the microphone 27 passes through the electronic component 23 group, is processed by the MPU 24, and is radiated from the antenna 25 to the outside.
[0004]
[Problems to be solved by the invention]
However, while further downsizing of electronic devices is progressing, sufficient heat dissipation performance cannot be obtained with the shape of a conventional circuit board. Therefore, for example, in the case of the mobile phone described above, it is impossible to downsize the circuit board 22 to be smaller than the projected area of the group of electronic components 23. At present, the thickness of the circuit board 22 and the electronic component 23 is large. This hinders downsizing and leads to increased costs. Therefore, it is conceivable to make the circuit board 22 multi-layered, but in that case, the wiring length between components becomes long, and jitter control becomes difficult.
[0005]
In view of the above-described problems, an object of the present invention is to provide a thin circuit board capable of reducing the size and weight of an electronic device.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention according to claim 1 is provided with flexibility in which a wiring and a component to be mounted by connecting to the wiring are arranged on the side of the film substrate. a thin circuit board as the wiring, the film is a thin film wiring than the thickness of the substrate, the component is the I thin film component der than the thickness of the wiring, and is formed separately on the film characterized in der Rukoto while a circuit board with components and wiring by freely deformed can be stored into the interior of the device. Therefore, it is not necessary to design the device to be larger than the projected area of the circuit board, and the device can be reduced in size and weight.
Further, the present invention 請 Motomeko 2 described in thin circuit board according to claim 1 Symbol placement, the thin film device is characterized in that the one formed by vapor deposition or sputtering.
According to a third aspect of the present invention, in the thin circuit board according to the first or second aspect , the film substrate including the wiring and the component is laminated, and the wirings of each layer are connected to each other. The connecting portion for connecting the substrate is arranged along the thickness direction in the film substrate. Since the components are also arranged inside the substrate, the number of components to be mounted on the substrate surface can be reduced. . Therefore, the board surface area required for mounting is small, and the circuit board can be downsized accordingly. When the film substrate is a resin film, wiring and electronic components can be embedded in the resin film layer, so that the circuit substrate can be further thinned.
[0010]
The present invention according to claim 4 is a thin circuit board having flexibility, wherein a wiring and a component to be mounted by connecting to the wiring are arranged on the side of the film substrate. The wiring is thinner than the thickness of the film substrate, the component is thinner than the thickness of the wiring, and a piezoelectric element capable of converting an amount of deformation of the substrate itself and an electric signal between the wirings on the surface of the film substrate. Since it is possible to convert the amount of deformation of the circuit board itself into an electrical signal, or on the contrary, the circuit board can be deformed by the electrical signal, the equipment can be configured with a small number of parts. This makes it possible to reduce the size, weight, and cost of the equipment.
[0011]
According to a fifth aspect of the present invention, in the thin circuit board according to any one of the first to fourth aspects, an arbitrary portion around a portion to which a desired three-dimensional shape is imparted is heat-sealed, and a sealed portion It is characterized by the fact that the space is in a vacuum state, and by providing a three-dimensional shape corresponding to the shape of the device housing, it can be placed in a desired position inside the housing Become. Therefore, the degree of freedom of shape when designing the housing and equipment is increased, the performance of the equipment can be improved, the design time and the production time can be shortened, and the production cost can be reduced. Moreover, the shape can be fixed permanently.
[0012]
According to a sixth aspect of the present invention, after an arbitrary portion of the thin circuit board according to any one of the first to fourth aspects is deformed into a desired three-dimensional shape by vacuum suction, an arbitrary portion around the deformed portion is selected. Heat is applied to the portions to heat-seal, and the space between the sealed portions is evacuated to fix the three-dimensional shape.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 shows a cross section of a thin circuit board according to Embodiment 1 of the present invention.
[0014]
A wiring 2 thinner than the thickness of the base 1 is formed on the surface of the base 1 made of a resin film, and a thin component 3 thinner than the thickness of the wiring 2 is mounted in a gap between the wirings 2 to have flexibility. A flat thin circuit board 4 is formed.
[0015]
The wiring 2 is made of copper having high conductivity, and is formed by performing an etching process after forming a copper film. Each of the thin components 3 performs functions such as a capacitor, a coil, a resistor, and a transformer in an electronic circuit, and is mounted by vapor deposition or sputtering of a conductive material, or the device is placed on a separate film. It is formed and mounted by soldering it to the wiring 2.
[0016]
That is, when the circuit board 4 is manufactured, the flexible base 1 called a resin film is used, and the thickness of the wiring 2 is made as thin as possible by using copper having high conductivity, and is thinner than the wiring 2. By mounting the thin component 3, the secondary moment related to the cross section of the board is lowered, the entire circuit board 4 is bent, and can be freely deformed.
[0017]
As a result, even if the circuit board 4 has the same size as a conventional circuit board that cannot be deformed, the circuit board 4 can be stored in a smaller gap, thereby contributing to the reduction in size and weight of the device. Even when a non-thin component (for example, the microphone 27 shown in FIG. 4) is mounted on the circuit board 4, it can be stored in a smaller gap than before by deforming the peripheral portion of the mounting portion.
[0018]
In addition, as a resin film which comprises the base 1, what was formed in the thickness of 5 micrometers-150 micrometers which has flexibility, for example with materials, such as PET, a polyimide, PPS, can be used. Instead of the resin film, a metal film such as an aluminum foil may be used. When an aluminum foil is used, an insulating layer is formed with an epoxy resin or the like, but when an oxide film is formed on the surface, the resin insulating layer is not essential. The wiring 2 may be formed of a conductive material such as palladium, gold, or silver in addition to the copper described above. (Embodiment 2)
FIG. 2 shows a cross section of a thin circuit board according to Embodiment 2 of the present invention.
[0019]
The thin circuit board 5 of the second embodiment is different from the thin circuit board of the first embodiment described above in that the wiring 2 and the thin component 3 arranged on the surface of the base 1 are laminated in a plurality of stages as one unit. The connection part 6 that connects the wirings 2 of the upper and lower layers is arranged inside the base 1. The thin circuit board 5 is flat and flexible, as in the thin circuit board of the first embodiment.
[0020]
In this circuit board 5, the electrical signal output from the thin component 3 disposed on the first layer on the surface is transmitted to the thin component 3 on the second layer via the wiring 2, the connection portion 6, and the wiring 2. The electrical signal output from the second-layer thin part 3 is transmitted to the third-layer thin part 3 through the wiring 2, the connection portion 6, and the wiring 2. In this way, transmission of electrical signals between the layers is performed through the shortest wiring path, so that the circuit board 5 is not affected by disturbances such as noise and the performance of the circuit board 5 is high.
[0021]
In addition, since the circuit board 5 has a configuration in which the thin parts 12 are arranged, it is possible to minimize the area and the number of parts required for surface mounting during manufacture, and it is possible to further reduce the size. is there. Therefore, it is possible to store the circuit board 5 in a smaller gap than in the case of using a conventional circuit board that cannot be deformed and in the case of using the thin circuit board of the first embodiment.
(Embodiment 3)
FIG. 3 shows a cross section of a thin circuit board according to Embodiment 3 of the present invention.
[0022]
The thin circuit board 7 of the third embodiment has substantially the same configuration as the thin circuit board of the second embodiment described above, but is different in that a concave bent portion 8 is formed.
[0023]
When the circuit board 7 is manufactured, first, a flat circuit board similar to that of the second embodiment is formed. Next, a desired part of the flat circuit board is vacuum-sucked from the back side (base 1 side) to be transformed into a desired shape, for example, a three-dimensional shape corresponding to the shape of the housing to be stored. Let Here, the bent portion 8 is formed by being deformed into a concave shape. Thereafter, heat sealing is performed by applying heat to a desired position, for example, a position indicated by an arrow H, so that a substantially vacuum state is established between the sealed portions. As a result, the shape of the bent portion 8 can be permanently fixed.
[0024]
In this way, since the circuit board 7 that can be efficiently stored inside the housing of the device can be manufactured, the degree of freedom in designing the housing and the device is increased, and the performance of the device can be improved. Time and manufacturing time can be shortened, and manufacturing cost can be reduced.
[0025]
In the third embodiment, the vacuum suction method is used to deform the flat circuit board, but a hot pressing method may be used. Further, heat sealing may be omitted when the internal irregularities are not a problem or when there is no influence of humidity.
(Embodiment 4)
FIG. 4 shows a cross section of a thin circuit board according to Embodiment 4 of the present invention.
[0026]
The thin circuit board 9 according to the fourth embodiment has substantially the same configuration as the thin circuit board according to the second embodiment described above. However, the piezoelectric element 10 detects the deflection of the circuit board 9 itself and outputs it as an electrical signal. It differs in that it is equipped with.
[0027]
When the circuit board 9 is manufactured, the wiring 2 is formed on the base 1 and the piezoelectric element 10 connected to the wiring 2 is formed by, for example, sputtering between the wirings 2. Then, in order to enclose the piezoelectric element 10, a structure in which the wiring 2 and the thin component 3 are arranged on the surface of the base 1 is laminated as a unit in a plurality of stages, and the wirings 2 of each layer are connected to each other inside the base 1. The connection is made by the connection unit 6.
[0028]
In such a circuit board 9, when the base 1 bends due to energy from the outside, the piezoelectric element 10 is also deformed, and the deformation amount is output as a voltage and transmitted as an electric signal through the wiring 2. When the external energy supply is cut off, the base 1 is not bent, no voltage is output from the piezoelectric element 10, and the electric signal is cut off.
[0029]
Therefore, by using this mechanism as an acoustic element for input / output of sound, for example, by configuring a speaker or a microphone, it is possible to realize a reduction in size and weight of the device. It is also possible to construct a vibrator using this mechanism for generating vibration. For example, if the piezoelectric elements are arranged on both sides of the shaft, and the piezoelectric elements are configured to contract and expand as the voltage is turned on and off and rotate around the shaft, the amount of deformation of the circuit board 9 is large.
[0030]
In the above, the example in which the deformation amount of the base 1 is detected by the piezoelectric element 10 has been described. However, other elements such as spring contacts may be used as long as the deformation amount can be detected.
[0031]
【The invention's effect】
As described above, the circuit board of the present invention is thinned by arranging the wiring thinner than the thickness of the film board and the mounting parts thinner than the thickness of the wiring board on the side of the film board , and the circuit board. Since the entire substrate is flexible and flexible, it can be easily stored inside the device, and the device can be reduced in size and weight.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a thin circuit board according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of a thin circuit board according to Embodiment 2 of the present invention. FIG. 4 is a cross-sectional view of a thin circuit board according to Embodiment 4 of the present invention. FIG. 5 is a configuration diagram of a conventional mobile phone that can use the circuit board of the prior art or the present invention.
1 Base (film substrate)
2 Wiring 3 Thin component 4 Thin circuit board 5 Thin circuit board 6 Connection part 7 Thin circuit board 8 Curved part 9 Thin circuit board
10 piezoelectric elements

Claims (6)

A thin circuit board having flexibility, wherein a wiring and a component connected to and mounted on the surface of the film substrate are arranged laterally on the surface of the film substrate, wherein the wiring is more than the thickness of the film substrate. thin a thin wire, the components I thin film component der than the thickness of the wiring, and a thin circuit board, characterized in der Rukoto those formed separately on the film. 2. The thin circuit board according to claim 1, wherein the thin film component is formed by vapor deposition or sputtering . The film substrate including the wiring and the component is laminated, and a connection portion for connecting the wirings of each layer is disposed in the film substrate along a thickness direction. 3. The thin circuit board according to any one of 2 above. A thin circuit board having flexibility, in which a wiring and a component to be connected to and mounted on the surface of the film substrate are arranged laterally on the surface of the film substrate, wherein the wiring is thinner than the thickness of the film substrate. The thin circuit is characterized in that the component is thinner than the wiring, and a piezoelectric element capable of converting an amount of deformation of the substrate itself and an electric signal is mounted between the wirings on the surface of the film substrate. substrate. The arbitrary place around the part provided with the desired three-dimensional shape is heat-sealed, and the space between the sealed parts is in a vacuum state. Thin circuit board. An arbitrary portion of the thin circuit board according to any one of claims 1 to 4 is deformed into a desired three-dimensional shape by vacuum suction, and then heat is applied to an arbitrary portion around the deformed portion for heat sealing. A method for producing a thin circuit board, wherein the space is sealed between the sealing portions to fix the three-dimensional shape.

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