JP4412034B2 - Surface mount type temperature sensor - Google Patents

Description

  The present invention relates to a surface mount type temperature detecting element in which a thermistor and a resistor are combined.

  Conventionally, in order to achieve downsizing and one chip, a chip-like thermistor element body, terminal electrodes formed on both end faces of the thermistor element body, and a resistor layer formed on the side surface of the thermistor element body are provided. A composite element in which a first terminal electrode, a resistor layer, a thermistor body, and the other terminal electrode are connected in series in this order has been proposed (for example, see Patent Document 1).

However, the composite element having such a configuration does not realize linearization of the thermistor characteristics, and has a problem that a separate resistor is required.
In addition, since a configuration that facilitates heat transfer to the thermistor body is not provided, there is a problem in the reliability of the accuracy with which the thermistor detects the temperature.
JP-A-10-294207

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a surface-mounted temperature detecting element that is excellent in linear characteristics and improved in the accuracy with which a thermistor detects temperature.

  According to a first aspect of the present invention, there is provided a surface mount type temperature detecting element having first and second thermistors disposed on a substrate and first to third resistors, and formed on a side portion of the substrate. One terminal electrode and a second terminal electrode, and one terminal is connected to the first terminal electrode, and the other terminal is connected to the second terminal electrode through the first resistor. A first thermistor and a second thermistor having one terminal connected to the first terminal electrode and the other terminal connected to the second terminal electrode via the second resistor; One terminal is connected to the first terminal electrode, and the other terminal has a third resistor connected to the second terminal electrode, and a resin molded over the substrate. Features.

  Invention of Claim 2 is invention of Claim 1, Comprising: The said 1st terminal electrode and said 2nd terminal electrode which are formed in the edge part of the said board | substrate were electrically insulated It further has a thermal coupling terminal.

  Invention of Claim 3 is invention of Claim 1 or 2, Comprising: At least in the area | region corresponding to the area | region where the said 1st and 2nd thermistor is arrange | positioned on the back surface of the said board | substrate. It further has a heat conductive film formed and connected to the thermal coupling terminal.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a width of a connection portion between the first terminal electrode and the first thermistor, and the first The width of the connection portion between the second terminal electrode and the second thermistor is formed narrower than the width of the connection portion between the thermal coupling terminal and the thermal conductive film.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the first thermistor and the second thermistor are oriented in the same direction and the side of the substrate. It is characterized in that it is arranged on the substrate so that the distance from the part becomes equal.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the resin is molded by including a filler having high thermal conductivity.

  According to a seventh aspect of the present invention, in the surface mount type temperature detecting element configured by disposing a thermistor and a resistor on the substrate, the first terminal electrode and the second terminal formed on the side portion of the substrate An electrode, at least two series circuits configured by connecting the resistor and the thermistor in series, and the at least two series circuits with respect to the first terminal electrode and the second terminal electrode, respectively. It has the parallel circuit comprised by connecting in parallel, and resin molded over the said board | substrate.

  According to the first aspect of the present invention, it is possible to provide a surface mount type temperature detecting element having linear resistance characteristics over a wide temperature range. In addition, since the substrate is molded with resin, a surface-mounted temperature detecting element that can be easily handled can be provided.

  According to the second aspect of the present invention, since the thermal coupling terminal that is electrically insulated from the first terminal electrode and the second terminal electrode is further formed, heat is efficiently applied to the surface mount type temperature detecting element. Can communicate. Further, by using the thermal coupling terminal as a fixing terminal, the surface mount type temperature detecting element can be more reliably fixed.

  According to the third aspect of the present invention, at least the first and second thermistors are disposed in the corresponding region on the back surface of the substrate, and the thermally conductive film connected to the thermal coupling terminal is provided. Furthermore, since it is provided, heat can be efficiently transmitted by the first and second thermistors, and the temperature detection accuracy can be improved.

  According to the fourth aspect of the present invention, the width of the connection portion between the first terminal electrode and the first thermistor and the width of the connection portion between the second terminal electrode and the second thermistor are thermal. Since it is formed to be narrower than the width of the connecting portion between the coupling terminal and the heat conducting film, the heat flowing out from one or both of the first and second thermistors by heat conduction can be reduced, and surface mounting The temperature detection accuracy of the mold temperature detection element can be improved.

  According to the fifth aspect of the present invention, since the first thermistor and the second thermistor are arranged on the substrate in the same direction and the distance from the side portion of the substrate is equal, Provided is a surface-mounting type temperature detecting element that can transmit heat transmitted from a portion equally to the first and second thermistors, can suppress a deviation in linear characteristics due to temperature distribution in the element, and is more excellent in linear characteristics. Can do.

  According to the invention described in claim 6, since the resin is molded by including a filler having high thermal conductivity, the heat around the surface mount type temperature detecting element is efficiently transmitted to the first and second thermistors. Temperature detection accuracy can be improved.

  According to the invention described in claim 7, since at least two or more circuits in which the thermistor and the resistor are connected in series are connected in parallel to the first terminal electrode and the second terminal electrode, Linearization of resistance characteristics can be realized in a wider temperature range.

FIG. 1A is a plan view showing a circuit configuration of a surface-mounted temperature detecting element 1a according to the first embodiment of the present invention.
A first terminal electrode 3 and a second terminal electrode 4 are formed on the glass epoxy substrate 2. On the glass epoxy substrate 2, resistors 6 (6a, 6b, 6c) and thermistors 7 (7a, 7b) are arranged.
In this embodiment, the glass epoxy substrate 2 is used as a substrate, but the present invention is not limited to this, and other substrates such as a ceramic substrate can also be used.
One terminal of the thermistor 7a is connected to the first terminal electrode 3 through the conductor pattern 8a. The other terminal of the thermistor 7a is connected to one terminal of the resistor 6a through the conductor pattern 8b. The other terminal of the resistor 6a is connected to the second terminal electrode 4 through the conductor pattern 8c.

One terminal of the resistor 6b is connected to the first terminal electrode 3 through the conductor pattern 8a. The other terminal of the resistor 6b is connected to the second terminal electrode 4 through the conductor pattern 8c.
One terminal of the resistor 6c is connected to the first terminal electrode 3 through the conductor pattern 8a. The other terminal of the resistor 6c is connected to one terminal of the thermistor 7b through the conductor pattern 8d. The other terminal of the thermistor 7b is connected to the second terminal electrode 4 through the conductor pattern 8c.

As shown in FIG. 1A, the thermistor 7a and the thermistor 7b are preferably arranged on the glass epoxy substrate 2 in the same direction. In FIG. 1A, the thermistors 7a and 7b are both arranged in the longitudinal direction.
Further, it is preferable to arrange the thermistors 7a and 7b and the distances from the side portions of the glass epoxy substrate 2 to be equal. In FIG. 1A, the distance between the first terminal electrode 3 and the thermistor 7a and the distance between the second terminal electrode 4 and the thermistor 7b are equal to each other on the glass epoxy substrate 2.
By constructing the surface mount type temperature detecting element 1a in this way, it is possible to equalize the heat transferred from the sides of the glass epoxy substrate 2 to the thermistors 7a and 7b by thermal conduction, and to the temperature distribution in the element. The deviation of the resulting linear characteristic can be suppressed and the temperature detection accuracy can be improved.

In the present embodiment, the resistor 6a is 9.31 kΩ, the resistor 6b is 13.3 kΩ, and the resistor 6c is 53.6 kΩ. Further, an NTC (Negative Temporture Coefficient) thermistor having characteristics of 10 kΩ as the thermistor 7 a and 100 kΩ as the thermistor 7 b was used.
As a method of constructing a circuit on the glass epoxy substrate 2, a method of mounting each element of the resistor 6 and the thermistor 7 on the glass epoxy substrate 2 may be used, or the resistor 6 and the thermistor 7 may be mounted on the glass epoxy substrate 2. Alternatively, a printing method may be used.

FIG. 1B is an equivalent circuit diagram of a circuit on the glass epoxy substrate 2 of the surface mount type temperature detecting element 1a according to the present embodiment shown in FIG.
That is, the electrical circuit shown in FIG. 1A includes a circuit in which a resistor 6a and a thermistor 7a are connected in series, a circuit in which a resistor 6c and the thermistor 7b are connected in series, and a resistor 6b, This is equivalent to an electric circuit connected in parallel to the terminal electrode 3 and the second terminal electrode 4.

FIG. 2A is a perspective view showing the appearance of the surface-mounted temperature detecting element 1a according to the present embodiment.
After the circuit shown in FIG. 1A is formed on the glass epoxy substrate 2, the glass epoxy substrate 2 is molded with a resin 9 and sealed. Thereafter, the range A1 in FIG. 1A is cut with a dicing saw to form one chip, whereby the surface-mounted temperature detecting element 1a is obtained.
By molding and sealing the glass epoxy substrate 2 with the resin 9, the circuit constituted by the resistor 6 and the thermistor 7 can be protected and the convenience of handling is improved.

Terminals 13a and 13b appear on the front surface of the surface-mounted temperature detecting element 1a. In the present embodiment, the terminals 13 a and 13 b are electrically connected inside the surface-mounted temperature detecting element 1 a and function as the first terminal electrode 3.
Further, terminals 13c and 13d appear on the back surface of the surface-mounted temperature detecting element 1a. In the present embodiment, the terminals 13 c and 13 d are electrically connected inside the surface mount type temperature detecting element 1 a and function as the second terminal electrode 4.
The size of the surface-mounted temperature detecting element 1a is, for example, L = 4.5 ± 0.2 (mm), W = 3.2 ± 0.2 (mm), T = 2.0 (mm) Can be configured.

As the resin 9 for molding the glass epoxy substrate 2, a resin 9 containing a filler having high thermal conductivity can be used. By configuring the resin 9 in this manner, heat is easily transmitted to the thermistors 7a and 7b via the filler having excellent thermal conductivity, and the sensitivity for detecting the temperature of the thermistors 7a and 7b can be improved.
As another sealing method, after sealing the periphery of the thermistors 7a and 7b that detect heat using a material having high thermal conductivity, the entire glass epoxy substrate 2 is protected from the outside. You may make it mold with the material strong against an impact. By molding the glass epoxy substrate 2 in this way, it is possible to obtain the surface-mounted temperature detecting element 1 that is easy to transmit heat to the thermistors 7a and 7b and that is resistant to external impacts.

  FIG. 2B is a back view of the surface-mounted temperature detecting element 1a according to the present embodiment as viewed from below. Terminals of a first terminal electrode 3 and a second terminal electrode 4 are respectively formed at both ends of the glass epoxy substrate 2. The terminal 13 a and the terminal 13 b function as the first terminal electrode 3. The terminals 13 c and 13 d function as the second terminal electrode 4.

FIG. 3 is a graph showing the effect when the surface-mounted temperature detecting element 1a according to the present embodiment is used. The resistance value R indicated by the surface-mounted temperature detecting element 1a changes according to the temperature T detected by the surface-mounted temperature detecting element 1a. In the graph of FIG. 3, the horizontal axis represents the temperature T (degrees) and the vertical axis represents the resistance value R (kΩ) indicated by the surface-mounted temperature detecting element 1 a, and the relationship between the temperature T and the resistance R is shown. Are plotted.
As the temperature T rises, the resistance value R decreases linearly, indicating a very linear temperature characteristic. The surface-mounted temperature detecting element 1a according to the present embodiment has a resistance value of 10 kΩ and a temperature coefficient of −50 (Ω / degree) when the temperature is 25 degrees.
The resistance temperature characteristic is given by the following (1).

  R (T) = − 0.05 × (T−25) +10 (1)

  According to the present embodiment, the surface mount type temperature detecting element that has excellent linear characteristics over a wide temperature range and can achieve a temperature accuracy with an error of ± 2 degrees with respect to the temperature characteristics shown in the equation (1). 1a can be obtained. Moreover, since it is a surface-mounted temperature detecting element, it is possible to reduce the size of an electronic device or the like to which the surface-mounted temperature detecting element 1a is mounted, and to improve the convenience of handling.

FIG. 4 is a plan view showing a structure of a surface mount type temperature detecting element detecting element 1b according to the second embodiment of the present invention. About the part which has the same structure as 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
In the surface mount type temperature detecting element 1 a according to the first embodiment, the first terminal electrode 3 and the second terminal electrode 4 are constituted by two terminals. However, the surface mount type temperature detecting element 1b according to the second embodiment is different in that a thermal coupling terminal 10 is further provided as a terminal. The thermal coupling terminal 10 is electrically insulated from the first terminal electrode 3, the second terminal electrode 4, the resistor 6, and the thermistor 7. The thermal coupling terminal 10 is used to efficiently transfer heat from an electronic device or the like whose temperature is to be measured by the surface-mounted temperature detecting element 1b to the surface-mounted temperature detecting element 1b.
The surface mount type temperature detecting element 1b can be obtained by molding and sealing the resin 9 on the glass epoxy substrate 2 shown in FIG.

  The external appearance of the surface-mounted temperature detecting element 1b according to the present embodiment is the same as that shown in FIG. However, the terminal 13a is electrically insulated and functions as a thermal coupling terminal 10 that plays a role of transferring heat into the surface-mounted temperature detecting element 1b. Further, the terminal 13 b functions as the first terminal electrode 3. Further, the terminals 13 c and 13 d function as the second terminal electrode 4.

FIG. 4B is a back view of the surface mount type temperature detecting element 1b according to the present embodiment.
A heat conductive film 14 is formed in a region corresponding to a region where the thermistor 7 (7 a, 7 b) is disposed on the glass epoxy substrate 2 and on the back surface of the glass epoxy substrate 2. The heat conductive film 14 is connected to the thermal coupling terminal 10. A resist film 11 is formed on a partial region on the back surface of the glass epoxy substrate 2 of the surface mount type temperature detecting element 1 b so as to cover the glass epoxy substrate 2 and the heat conductive film 14.

With such a configuration, the area of the heat conductive film 14 is formed large, and the heat conductive film 14 is disposed close to the thermistor 7 (7a, 7b) via the glass epoxy substrate 2. Therefore, the heat flowing in from the thermal coupling terminal 10 can be efficiently transmitted to the thermistor 7 (7a, 7b). Therefore, the sensitivity of the thermistor 7 (7a, 7b) to heat can be improved.
Further, by using the thermal coupling terminal 10 to fix the surface mount type temperature detecting element 1b, the surface mount type temperature detecting element 1b can be more securely fixed to a substrate such as an electronic device.
Further, by covering the thermal conductive film 14 formed on the back surface of the glass epoxy substrate 2 and forming the resist film 11, a short mode caused by solder or the like is caused when the surface mount type temperature detecting element 1b is mounted. It can prevent problems from occurring.
In the above description, the case where the thermal coupling terminal 10 is formed on the first terminal electrode 3 side has been described. However, the present invention is not limited to this, and the second terminal electrode 4 side of the glass epoxy substrate 2 is not limited thereto. You may make it form in a side part and another side part.

FIG. 5 is a plan view showing the structure of a surface-mounted temperature detecting element 1c according to the third embodiment of the present invention. Parts having the same configurations as those of the first and second embodiments are denoted by the same reference numerals and description thereof is omitted.
The shape of the conductor patterns 8a and 8c (see FIG. 1A) is different from the surface-mounted temperature detecting element 1b according to the second embodiment. That is, a part of the conductor width of the conductor patterns 8 e and 8 f (FIG. 5) is formed to be narrower than the conductor connecting the thermal coupling terminal 10 and the heat conductive film 14. Since a part of the conductor width of the conductor patterns 8e and 8f is narrow, heat is not easily transmitted in this part, and heat escaping from the thermistors 7a and 7b through the conductor patterns 8e and 8f can be reduced. it can. Therefore, the thermistors 7a and 7b can store more heat, and the sensitivity of the thermistors 7a and 7b to heat can be improved.

  In addition, although the surface mount type temperature detection element 1 (1a, 1b, 1c) by the 1st-3rd embodiment was each demonstrated separately, the content demonstrated in each embodiment was combined, respectively, and a surface mount type temperature detection element 1 can also be formed.

In the first to third embodiments, the resistors 6a, 6b, 6c and thermistors 7a, 7b are used on the glass epoxy substrate 2 as shown in the equivalent circuit of FIG. The case of configuring an electric circuit has been described. However, the circuit configured on the glass epoxy substrate 2 is not limited to this.
For example, an electric circuit configured by an equivalent circuit shown in FIG. 6 can be configured on the glass epoxy substrate 2. That is, a circuit in which the resistor 6d and the thermistor 7c are connected in series, a circuit in which the resistor 6e and the thermistor 7d are connected in series, the thermistor 7e, and the resistor 6f are connected to the first terminal electrode 3 and the second terminal electrode 4 respectively. The electric circuit can also be configured to be connected in parallel. By adopting such a configuration, it is possible to obtain a surface mount type temperature detecting element having linear resistance characteristics in a wider temperature range.

  In the above description, two circuits in which a resistor and a thermistor are connected in series are included, and the two series circuits are connected in parallel to the first terminal electrode 3 and the second terminal electrode 4, respectively. However, the present invention is not limited to this. That is, the number of circuits in which resistors and thermistors are connected in series may be increased to three or more in parallel with respect to the first terminal electrode 3 and the second terminal electrode 4. By adopting such a configuration, it is possible to obtain the surface mount type temperature detecting element 1 having linear resistance characteristics in a wider temperature range.

  In the above description, the case where the resistor 6 and the thermistor 7 are independently arranged on the glass epoxy substrate 2 to form an electric circuit has been described. However, the present invention is not limited to this. That is, an electric circuit can be configured using a composite element in which the resistor 6 and the thermistor 7 are combined into a single chip. In this way, the number of elements arranged on the glass epoxy substrate 2 can be reduced, and the surface mount type temperature detecting element 1 can be further downsized.

  As mentioned above, although this invention was demonstrated along embodiment, this invention is not restrict | limited to these. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

  It can be used for temperature compensation of various sensors, temperature detection of various electronic devices, and temperature compensation.

It is a figure for demonstrating the circuit structure of the surface mount-type temperature detection element 1a by the 1st Embodiment of this invention. It is a figure for demonstrating the shape of the surface mount type temperature detection element 1a by this embodiment. It is a graph which shows the effect of the surface mount type temperature detection element 1a by this embodiment. It is a figure for demonstrating the surface mounted type temperature detection element 1b by the 2nd Embodiment of this invention. It is a top view for demonstrating the surface mounted type temperature detection element 1c by the 3rd Embodiment of this invention. It is a circuit diagram which shows the structure of the other electric circuit formed on the glass epoxy board | substrate 2 of the surface mount-type temperature detection element 1 by embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b, 1c ... Surface mount type temperature detection element 2 ... Glass epoxy board 3 ... 1st terminal electrode 4 ... 2nd terminal electrode 6a, 6b, 6c, 6d, 6e, 6f ... Resistors 7a, 7b, 7c, 7d, 7e ... Thermistors 8a, 8b, 8c, 8d, 8e ... Conductor pattern 9 ... Resin 10 ... Thermal coupling terminal 11 ... Resist film 13a, 13b, 13c, 13d ... terminal 14 ... heat conduction film

Claims (6)

In the first and second thermistors disposed on the substrate, and the surface-mounted temperature detecting element having the first to third resistors,
A first terminal electrode and a second terminal electrode formed on a side portion of the substrate;
A first thermistor having one terminal connected to the first terminal electrode and the other terminal connected to the second terminal electrode via the first resistor;
A second thermistor having one terminal connected to the second terminal electrode and the other terminal connected to the first terminal electrode via the second resistor;
A third resistor having one terminal connected to the first terminal electrode and the other terminal connected to the second terminal electrode;
Resin molded over the substrate;
A surface mount type temperature detecting element characterized by comprising:   The surface mount device according to claim 1, further comprising a thermal coupling terminal electrically insulated from the first terminal electrode and the second terminal electrode formed on a side portion of the substrate. Mold temperature detection element.   It further comprises a heat conductive film formed on at least a region corresponding to a region where the first and second thermistors are disposed on the back surface of the substrate and connected to the thermal coupling terminal. The surface mount type temperature detecting element according to claim 2.   The width of the connecting portion between the first terminal electrode and the first thermistor and the width of the connecting portion between the second terminal electrode and the second thermistor are determined by the thermal coupling terminal and the heat conduction. 4. The surface-mounting type temperature detecting element according to claim 2, wherein the surface-mounting type temperature detecting element is formed to be narrower than a width of a connecting portion between the films.   The first thermistor and the second thermistor are arranged on the substrate so that the directions of the first thermistor and the second thermistor are the same, and the distance from the side of the substrate is the same. A surface-mounted temperature detecting element according to any one of the above items.   The surface mount type temperature detecting element according to any one of claims 1 to 5, wherein the resin is molded by including a filler having high thermal conductivity.

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