JP2002141208A - Chip-type composite electronic component, temperature sensor, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts of a varistor or a bypass capacitor connected to an NTC thermistor. SOLUTION: A chip-type composite electronic component is provided with a structural part, in which an NTC thermistor chip element 21 displaying the characteristics of an NTC thermistor 6 and varistor chip elements 22 and 23 which have a dielectric constant for displaying the characteristics of a varistor 10 and form the electrostatic capacitance of a bypass capacitor 11, are electrically connected in parallel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a chip-type composite electronic component including an NTC thermistor, a temperature sensor using the same, and an electronic device.

[0002]

2. Description of the Related Art Referring to FIGS. 7 to 9, an NTC having a characteristic (NTC characteristic) in which a resistance value decreases with an increase in temperature.
An example of using a C (negative characteristic) thermistor will be described.

FIG. 7 shows an internal circuit of an electronic device for detecting and displaying a temperature and compensating the temperature. 1 is a temperature detection circuit, 2 is an A / D converter, and 3 is an A / D converter.
Is a liquid crystal drive circuit, and 4 is a liquid crystal display circuit. The temperature detection circuit 1 has a fixed resistor 5 connected to the power supply side and an NTC thermistor 6 connected to the ground side, and connects the fixed resistor 5 and the NTC thermistor 6 in series to form a voltage dividing circuit. The divided voltage Vout can be inputted to the A / D converter 2 from the divided voltage point 7. The divided voltage Vout from the temperature detection circuit 1 decreases as the temperature rises as shown in FIG. 8 due to the NTC characteristics of the NTC thermistor 6, and includes temperature information.

The divided voltage Vout from the temperature detection circuit 1
Are converted into digital signals by the A / D converter 2 as temperature information, input to the liquid crystal drive circuit 3, and displayed on the liquid crystal display circuit 4. Here, the A / D converter 2, the liquid crystal drive circuit 3, and the liquid crystal display circuit 4 constitute a temperature signal processing circuit that processes the divided voltage Vout from the temperature detection circuit 1 as a temperature signal.

[0005] In the electronic device, among the electronic components constituting the temperature detecting circuit 1 in the component configuration, the NTC thermistor 6 is mounted on the daughter board 8 side.
The fixed resistor 5 which is another electronic component constituting the temperature detecting circuit 1 and the electronic components constituting the A / D converter 2, the liquid crystal driving circuit 3 and the liquid crystal display circuit 4 are mounted on the parent substrate 9 side, By routing the wiring between the two substrates 8 and 9, the child substrate 8 on which the electronic components for the temperature detection circuit 1 are mounted can be arranged near the target whose temperature is to be detected. All accurate temperature information is obtained.

[0009] As shown in FIG. 9, in the case of the NTC thermistor 6 mounted on the sub-board 8, since it is arranged near the temperature detection target, an ESD exceeding 10 kV is required.
A protection element such as a varistor 10 is connected in parallel with the NTC thermistor 6 in order to prevent the NTC thermistor 6 from being deteriorated in characteristics by being exposed to (electrostatic discharge). Further, a transient fluctuation of the divided voltage Vout can be suppressed.
A bypass capacitor 11 is connected in parallel with the NTC thermistor 6 to absorb a change in input impedance caused by the integration operation of the A / D converter 2.

In this case, generally, the varistor 10 is mounted on the sub-board 8 side, and the bypass capacitor 11 is mounted on the main board 9 side.

[0008]

In the above conventional example, N
Since each of the TC thermistor 6, the varistor 10, and the bypass capacitor 11 is configured as an individual component, the number of components is at least three, which leads to an increase in component cost and a large number of components. 8,
In addition, the mounting work of components on the electronic device 9 is increased, mounting costs are increased, and the mounting space is further increased, thereby hindering miniaturization of electronic devices.

Therefore, an object of the present invention is to reduce the number of parts of a varistor and a bypass capacitor connected to an NTC thermistor.

[0010]

(1) A chip-type composite electronic component according to the present invention comprises: a first chip element for imparting the characteristics of an NTC thermistor; and an electrostatic element for imparting the characteristics of a varistor and corresponding to a bypass capacitor. A NTC thermistor and a varistor having at least a second chip element having a relative dielectric constant necessary for forming a capacitor, wherein the two chip elements are laminated, and the laminated structure provides an electric equivalent circuit in an electric equivalent circuit. And a bypass capacitor constitute an integrated component connected in parallel.

According to the chip-type composite electronic component of the present invention,
Since it has the functions of an NTC thermistor, a varistor, and a bypass capacitor by itself, the number of parts is one compared to a conventional individual component configuration having these functions.
As a result, the cost of parts can be greatly reduced. Also, since the number of components is as small as one, the work of mounting the components on the board is reduced, so that the mounting cost can be greatly reduced, and the mounting space can be further reduced.
It is possible to promote downsizing of an electronic device equipped with these. In particular, in the case of the chip-type composite electronic component of the present invention, since the second chip body has two functions, namely, a varistor function and a bypass capacitor function by capacitance, each of the chip-type composite electronic components as a whole. Are further reduced in size, so that the mounting space is reduced, and the miniaturization of an electronic device in which these are mounted can be further promoted.

In Japanese Patent Application No. 5-69666 (Japanese Patent Application Laid-Open No. 6-283301), a plurality of chip-type electronic components are selected from the group consisting of chip-type resistors, chip-type thermistors, chip-type capacitors, and chip-type varistors. A chip-type composite electronic component having two or more types of selected chip-type electronic components is provided. However, there is no disclosure of the structure of the chip-type varistor regarding the chip-type composite electronic component according to the provision. There is no description or suggestion of a second element having a relative permittivity that forms a required capacitance corresponding to a bypass capacitor as in the invention.

In the case of the present invention, it is possible to provide a component having the same function as connecting an NTC thermistor, a varistor, and a bypass capacitor in parallel while using two chip bodies. It is possible to further reduce the thickness and size of the device, which is simply a three-layer structure of an NTC thermistor, a varistor, and a bypass capacitor, and to further contribute to the miniaturization of electronic devices.

(2) A temperature sensor according to the present invention includes a chip-type composite electronic component and a daughter board on which the chip-type composite electronic component is mounted, and the chip-type composite electronic component has NTC thermistor characteristics. A first chip body and a second chip body having a varistor characteristic and having a relative permittivity necessary for forming a capacitance corresponding to a bypass capacitor, and both chip bodies are laminated. And the above-described laminated structure provides N
The TC thermistor, the varistor, and the bypass capacitor constitute an integrated component connected in parallel.

According to the temperature sensor of the present invention, the chip-type composite electronic component has the functions of the NTC thermistor, the varistor, and the bypass capacitor based on the capacitance of the varistor. Compared with the conventional configuration including the board and the mother board, the board size can be reduced, and the miniaturization of an electronic device on which the board is mounted can be promoted.

(3) An electronic device according to the present invention is an electronic device comprising: a daughter board; and a mother board, which is connected to the daughter board by wiring and has a temperature signal processing circuit mounted thereon.
A chip-type composite electronic component is mounted on the daughter board. The chip-type composite electronic component includes an NTC thermistor and a varistor having a dielectric constant necessary for forming a capacitance corresponding to a bypass capacitor. It has a structure that is electrically connected to each other in parallel and laminated and integrated,
A fixed resistor that constitutes a voltage dividing circuit together with the NTC thermistor by being connected in series with the NTC thermistor is mounted on the mother board, and the fixed resistor is connected to a power supply side, and An NTC thermistor mounted on the daughter board is connected to the ground side, and a temperature signal can be input to the temperature signal processing circuit from a voltage dividing point of the voltage dividing circuit.

According to the electronic device of the present invention, the sub-substrate has NT
C Thermistors, varistors, and chip-type composite electronic components each having the function of a bypass capacitor based on the capacitance of the varistor are mounted, so the number of varistor components mounted on the child board side and the number of bypass capacitor components mounted on the parent board side As a result, the mounting work becomes unnecessary and the mounting space can be reduced, so that the overall size is reduced. As a result, the cost and size are reduced compared to the configuration of a conventional electronic device equipped with these board devices. it can.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments shown in the drawings.

FIGS. 1 to 3 relate to an embodiment of the present invention. FIG. 1 is a perspective view of a chip-type composite electronic component, and FIG.
FIG. 3 is a sectional view of the chip-type composite electronic component shown in FIG. 1;
FIG. 2 is an electrical equivalent circuit diagram of the chip-type composite electronic component shown in FIG.

Referring to these drawings, a chip-type composite electronic component 20 of the present embodiment has a rectangular parallelepiped shape, and is provided with an NTC thermistor chip body 21 as a first chip body and two sides thereof. It has a laminated structure with two varistor chip bodies 22 and 23 as a second chip body.

The NTC thermistor chip body 21 is a sheet-like sintered body made of a plurality of kinds of oxides of transition metal elements such as nickel, cobalt and copper.

Each of the varistor chip bodies 22 and 23 is a sheet-shaped sintered body of a semiconductor ceramic containing zinc oxide as a main component, and its constituent material, zinc oxide, has a relative dielectric constant εr.
By having about 200, the capacitance of about 1000 pF corresponding to the capacitance of the bypass capacitor is obtained.

The NTC thermistor chip body 21
And first to fifth internal electrodes 24 to 28 are provided inside the varistor chip bodies 22 and 23, and the first, third and fifth internal electrodes 24, 26 and 28 are provided on one side surface. Is connected to the external electrode 29, and the second and fourth internal electrodes 25 and 27 are connected to the external electrode 3 on the other side surface.
0 is connected.

Chip type composite electronic component 2 having the above configuration
In the case of 0, NTC thermistor chip body 21 and both varistor chip bodies 22 and 23 form an equivalent circuit of NTC.
C thermistor 6, varistor 10, and varistor 10
Is connected in parallel with the bypass capacitor 11 having the capacitance of.

In the case of the above-mentioned chip-type composite electronic component 20,
The NTC thermistor chip body 21 provides the function of the NTC thermistor 6 even though it has a simple structure composed of two chip bodies, and the varistor chip bodies 22 and 23 provide the varistor 10 and the bypass capacitor 1.
Since each function can be provided, only one component is required as compared with a conventional individual component configuration having each of these functions, and the cost of components can be significantly reduced.

Referring to FIG. 4, the configuration of an electronic device on which the chip-type composite electronic component 20 is mounted will be described. FIG. 4 shows an internal circuit of an electronic device for performing temperature display and temperature adjustment, and portions corresponding to FIG. 1 are denoted by the same reference numerals.

In FIG. 4, reference numeral 1 denotes a temperature detection circuit;
Denotes an A / D converter, 3 denotes a liquid crystal drive circuit, and 4 denotes a liquid crystal display circuit.

The temperature detecting circuit 1 has a fixed resistor 5 connected to the power supply side + Vcc and an NTC thermistor 6 connected to the ground side. The fixed resistor 5 and the NTC thermistor 6
Are connected in series to form a voltage dividing circuit, and the divided voltage Vout can be inputted to the A / D converter 2 from the voltage dividing point 7. Divided voltage V from temperature detection circuit 1
As shown in FIG. 8, out decreases with an increase in temperature due to the NTC characteristics of the NTC thermistor 6.

The divided voltage Vout from the temperature detection circuit 1
Is converted into a digital signal by the A / D converter 2 as a temperature signal, input to the liquid crystal drive circuit 3, and displayed on the liquid crystal display circuit 4.

A varistor 10 and a bypass capacitor 11 are connected in parallel to the NTC thermistor 6.

In the case of the present embodiment, as the electronic components constituting such a circuit configuration, an NTC thermistor 6, a varistor 10, and a bypass capacitor 11 are integrally formed by a single chip-type composite electronic component 20, and a temperature sensor is provided. While the fixed resistor 5 is mounted on the
, A / D converter 2, liquid crystal drive circuit 3, and liquid crystal display circuit 4
Are mounted on the parent board 9.

The two substrates 8 and 9 are connected by a wiring 30. The sub-substrate 8 can be disposed as a temperature sensor near the object whose temperature is to be detected. Chip-type composite electronic components 2 for objects
Thus, accurate temperature information can be obtained by the NTC thermistor 6 constituting 0.

In the above electronic equipment, a board device consisting of a child board 8 and a master board 9 is built in, and the three components of the NTC thermistor 6, the varistor 10, and the bypass capacitor 11 are circuit-wise. Child board 8 with one
Since the mounting work of the varistor 10 and the mounting space thereof are reduced in the child board 8 and the mounting work of the bypass capacitor and the mounting space thereof are reduced in the parent board 9, the mounting cost is greatly reduced and the mounting space is reduced. It is possible to reduce the size of the electronic device, and promote the reduction in the price and the size of the electronic device equipped with the device.

The present invention is not limited to the above embodiment, and various applications and modifications are possible.

(1) The chip-type composite electronic component 20 according to the above-described embodiment is configured by providing varistor chip bodies 22 and 23 on both sides of an NTC thermistor chip body 21. Like the composite electronic component 20 ',
One of the varistor chip bodies 22 may be provided, and the NTC thermistor chip bodies 21 and 21 may be provided on both sides of the varistor chip body 22.

The electrical equivalent circuit of the chip-type composite electronic component 20 'of FIG. 5 is the same as that of FIG. 3, and has the same operation and effect as the chip-type composite electronic component 20 of the above-described embodiment.

In each of the above embodiments, there are three chip bodies, but two of the chip bodies are the same. Therefore, the NTC thermistor is essentially composed of two chip bodies. And a component having a function equivalent to connecting a varistor and a bypass capacitor in parallel with each other. It is even thinner and smaller than the three-layer structure of the NTC thermistor, varistor and bypass capacitor. Therefore, it is possible to further contribute to miniaturization of electronic devices.

(2) The chip-type composite electronic component 20 of the above-described embodiment is composed of three chip bodies of the NTC thermistor chip body 21 and the varistor chip bodies 22 and 23. As shown by the mold composite electronic component 20 ″, a two-layer structure of the NTC thermistor chip body 21 and the NTC thermistor chip body 21 may be adopted.

The chip-type composite electronic component 20 ″ shown in FIG.
The electrical equivalent circuit is the same as that of FIG. 3 and has the same operation and effect as the chip-type composite electronic component 20 of the above-described embodiment.

(3) In the case of the chip-type composite electronic component 20 of the above embodiment, the room temperature resistance value of the NTC thermistor by the NTC thermistor chip body 21 is 10 kΩ, and the capacitance of the varistor chip bodies 22 and 23 is 1000 pF. The successive approximation type A /
A filter that removes noise generated when the input is switched in the D converter 2 and switching noise of the power supply line can be configured.

[0041]

As described above, according to the chip-type composite electronic component of the present invention, the first chip element for imparting the characteristics of the NTC thermistor and the electrostatic element for imparting the characteristics of the varistor and corresponding to the bypass capacitor are provided. A second chip element having a relative permittivity for forming a capacitor, and having a structure in which both chip elements are stacked in a state where they are electrically connected in parallel to each other. And the functions of the varistor and the bypass capacitor can be provided, and the number of components is reduced to one as compared with a conventional individual component configuration having these functions, so that the cost of components can be greatly reduced. Further, since the number of components is as small as one, the work for mounting each of these NTC thermistors, varistors and bypass capacitors on a substrate is reduced, so that the mounting cost can be greatly reduced, and the mounting space for the components is also reduced. As a result, it is possible to promote downsizing of an electronic device on which these are mounted.

[Brief description of the drawings]

FIG. 1 is a perspective view of a chip-type composite electronic component according to an embodiment of the present invention.

FIG. 2 is a sectional view of the chip-type composite electronic component of FIG. 1;

FIG. 3 is an electrical equivalent circuit diagram of the chip-type composite electronic component of FIG.

4 is a circuit diagram of an electronic device using the chip-type composite electronic component of FIG.

FIG. 5 is a sectional view of a chip-type composite electronic component according to another embodiment of the present invention.

FIG. 6 is a sectional view of a chip-type composite electronic component according to another embodiment of the present invention.

FIG. 7 is a circuit diagram of a conventional electronic device.

FIG. 8 is a voltage-temperature characteristic diagram of the NTC thermistor of FIG. 7;

FIG. 9 is a parallel circuit diagram of a varistor and a bypass capacitor for the NTC thermistor of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature detection circuit 2 A / D converter 5 Fixed resistor 6 NTC thermistor 7 Voltage dividing point 8 Substrate 9 Parent substrate 20 Chip-type composite electronic component 21 NTC thermistor chip body (first chip body) 22, 23 Varistor Chip body (second chip body)

Claims (3)

[Claims] 1. A first chip element that imparts the characteristics of an NTC thermistor, and a second chip element that imparts the characteristics of a varistor and has a relative dielectric constant necessary for forming a required capacitance corresponding to a bypass capacitor. And an integrated component in which an NTC thermistor, a varistor, and a bypass capacitor are connected in parallel in an electric equivalent circuit by the laminated structure. A chip-type composite electronic component. 2. A chip-type composite electronic component, comprising: a sub-board on which the chip-type composite electronic component is mounted, wherein the chip-type composite electronic component is provided with a first chip element that imparts the properties of an NTC thermistor; At least a second chip element having the relative permittivity required for forming the capacitance corresponding to the bypass capacitor, which imparts the characteristics of the varistor, and has a structure in which both chip elements are stacked, A temperature sensor, wherein the laminated structure forms an integrated component in which an NTC thermistor, a varistor, and a bypass capacitor are connected in parallel in an electric equivalent circuit. 3. An electronic device comprising: a child board; and a parent board connected to the child board by wiring and having a temperature signal processing circuit mounted thereon, wherein the child board has a chip-type composite electronic component. This chip-type composite electronic component is formed by laminating an NTC thermistor and a varistor having a relative dielectric constant required for forming a required capacitance corresponding to a bypass capacitor in parallel with each other. And a fixed resistor that constitutes a voltage dividing circuit together with the NTC thermistor by being connected in series with the NTC thermistor is mounted on the mother board. The fixed resistor is connected to the power supply side, the NTC thermistor mounted on the daughter board is connected to the ground side, and a temperature signal from the voltage dividing point of the voltage dividing circuit is the temperature signal. Is input configured to be able to sense circuit, electronic apparatus characterized.