JPH0766519A - Flexible substrate - Google Patents

Abstract

PURPOSE:To enable the electronic component using the title flexible substrate to be miniaturized thereby cutting down the manufacturing cost thereof. CONSTITUTION:The flexible substrate is formed of the circuit parts such as a trap filter component and an impedance matching component using at least one out of the reactance components of the wiring patterns 3 on the flexible substrate 1 and the parasitic capacitance generated between respective wiring patterns 3, 4 etc., as a constituent element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible board used for connecting various circuit parts.

[0002]

2. Description of the Related Art Conventionally, in an electronic device such as a handy type audio device having a small capacity for storing components, a flexible substrate which can be easily routed is used to connect a plurality of printed wiring boards on which various circuit components are mounted to each other. Is being done. In addition, such electronic devices include circuit components such as filter components and impedance matching components for the purpose of reducing unnecessary radiation and suppressing standing waves. These circuit components are, for example, circuit components such as capacitors and coils. Are connected to each other in a predetermined relationship and then mounted on a printed wiring board.

[0003]

By the way, in an electronic component using such a conventional flexible substrate,
There is a problem in that the mounting area of the printed wiring board increases due to the mounting of the circuit component elements that form the circuit component, which hinders the downsizing of the printed wiring board and the downsizing of the entire electronic component.

Further, there are problems that the number of parts is increased due to the provision of various circuit components and the manufacturing / assembling work is complicated, resulting in an increase in manufacturing cost.

Therefore, it is an object of the present invention to provide a flexible substrate which can reduce the size and manufacturing cost of electronic components using the flexible substrate.

[0006]

In order to achieve such an object, according to the present invention, at least the reactance component of the wiring pattern on the flexible substrate and the parasitic capacitance generated between the wiring patterns are at least included. A circuit board was formed by using one as a constituent element to form a flexible substrate.

[0007]

According to the above configuration, the reactance component and parasitic capacitance naturally generated on the flexible substrate are positively used as the circuit component element to configure the circuit component such as the filter component and the impedance matching component. And the need for mounting these circuit components is eliminated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view of a flexible substrate according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA.

The flexible substrate 1 is provided with a substrate body 2 made of a polyimide substrate, and on the surface of the substrate body 2, a signal line 3 and an earth line 4 arranged above and below the signal line 3 in the figure. , 4 are formed. Also,
A ground line 5 is formed on the entire back surface of the substrate body 2.

The flexible substrate 1 thus constructed
A trap filter component 6 is formed on the. As shown in FIG. 3, the trap filter component 6 is configured by connecting a pair of coils LI and L2, which are reactance components, and a capacitor C1 to each other in a T shape, and such a trap filter component 6 is an input stage. It is interposed between a transmission source 8 that generates a signal to be output to the device 7 and a driver circuit unit 9 that drives the device, and removes an unnecessary frequency signal generated by the transmission source 8. In FIG. 3, reference numeral 9 is a power source of the transmission source 8.

As described above, the trap filter component 6 is composed of the coils L1 and L2 and the capacitor C1. These elements L1, L2 and C1 are formed on the flexible substrate 1 as follows. That is, the signal line 3 itself has a reactance component, and the reactance component is used to form the coils L1 and L2. It should be noted that the reactance component needs to be changed depending on the resonance frequency, but the reactance component is adjusted by adjusting the line length, width, thickness, and material of the signal line 3. In this embodiment, the signal line 3 is made to meander on the surface of the substrate body 2 in order to obtain a sufficient reactance component.

Further, in the flexible substrate 1, parasitic capacitance is generated between the signal line 3 and the earth lines 4 and 4, and between the signal line 3 and the earth line 5. Therefore, the parasitic capacitance is positively used as a circuit component element to form the capacitor C1. The capacitance of the capacitor C1 can be adjusted by adjusting the distance between the signal line 3 and the ground lines 4 and 4 and the thickness of the substrate body 2.

The flexible substrate 1 having the trap filter component 6 formed therein in this way is the transmission source 8
And the driver circuit section 9 are connected, and the transmission source 8
It is also possible to remove the unnecessary frequency signal generated in. Therefore, it is not necessary to form such a trap filter component 6 from various circuit components, and further, it is not necessary to mount such various circuit components on a printed wiring board (not shown).

By the way, in the above embodiment, the trap filter component 6 is formed on the flexible substrate 1, but the present invention is not limited to such a filter component, and the impedance matching component 10 shown in FIG. It also includes the one formed above. That is, the impedance matching component 10 is arranged on a transmission line (a part or the whole of this transmission line can be configured by the flexible substrate 1) for transmitting a signal from the output stage 11 to the load 12, and the coil L3 which is a reactance component. It is composed by. In FIG. 3, C2 is a coupling capacitor that disconnects the output stage 11 and the load 12 from each other in terms of direct current. The coil L3 as described above can be formed by the reactance component generated in the signal line 3 of the flexible substrate 1 as in the above-described embodiment, and further, the reactance component can be adjusted by the line length and width of the signal line 3 as described above. It can be done by adjusting the thickness, thickness, and material.

The flexible substrate 1'in which the impedance matching component 10 is formed in this way connects the output stage 11 and the load 12, and the output stage 11 is connected.
The impedance can be adjusted between the load and the load 12. Therefore, it is not necessary to form the separate impedance adjusting component from the circuit component (coil element), and further, it is not necessary to mount such a circuit component on the printed wiring board (not shown).

[0016]

As described above, according to the present invention, the reactance component and the parasitic capacitance naturally generated in the flexible substrate are positively used as the circuit component element to configure the circuit component such as the filter component and the impedance matching component. , It is no longer necessary to configure these circuit components from a single circuit component. Therefore, the area of the mounting substrate can be reduced by the amount that these circuit constituent elements are unnecessary, and the miniaturization of the entire device can be achieved accordingly.

Further, since various single circuit constituent elements constituting the circuit component are not required, the number of components can be reduced and the manufacturing / assembling work can be simplified, and the manufacturing cost can be reduced accordingly.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of a flexible substrate according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a block diagram of a circuit including a trap filter component.

FIG. 4 is a block diagram of a circuit including an impedance matching component.

[Explanation of symbols]

 1 flexible substrate 3 signal line 4 earth line 5 earth line 6 trap filter component 10 impedance matching component

Claims (1)

[Claims] 1. A flexible substrate, wherein a circuit component is formed by using at least one of a reactance component of a wiring pattern on the flexible substrate and a parasitic capacitance generated between the wiring patterns as a constituent element.