JP2006278810A - Thin film temperature sensor and method for adjusting characteristics thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film temperature sensor which can achieve high precision output characteristics (voltage/temperature) without varying the characteristics of a thermistor by employing a voltage output arrangement having three terminals combining a thermistor and a resistor and adjusting the characteristics of resistance of a thermistor formed on a thermally insulated portion by a resistor formed on the outside of the thermal insulation portion and capable of trimming, and to provide a method for adjusting the characteristics thereof. <P>SOLUTION: The thin film temperature sensor 10b has through holes 9a-9d formed in a substrate 1b and a portion insulated thermally from other regions of the substrate 1b. The thin film temperature sensor 10b also has a heat-sensitive resistor portion 6 formed on the thermally insulated portion, and a resistor portion 3b formed on the substrate 1b and capable of trimming the resistance. Furthermore, a terminal electrode 5a being connected with one terminal of the resistor portion 3b, a terminal electrode 5b being connected with the other terminal of the resistor portion 3b and one terminal of the heat-sensitive resistor portion 6, and a terminal electrode 5c being connected with the other terminal of the heat-sensitive resistor portion 6 are formed on the substrate 1b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a thin film temperature sensor that adjusts a resistance value characteristic of a thin film thermistor by using a trimmable resistor and a characteristic adjusting method thereof.

Conventionally, as a method of improving the accuracy of the resistance value of a thin film thermistor, a method of directly trimming and adjusting the thin film resistance of the thin film thermistor with a laser is known. In this method, since the thin film resistor is directly trimmed with a laser, the thin film resistor is heated and evaporated by the laser irradiation heat, and the thin film resistor in the vicinity irradiated with the laser reacts with a protective film formed of glass or the like. There is a problem that the characteristic of the resistance value is partially deteriorated.
Furthermore, in the above method, since the thin film resistor or the like is directly formed on the insulating substrate, in the heat treatment process of the thin film resistor or protective film, a part of the components constituting the thin film resistor diffuses to the insulating substrate depending on the heat treatment temperature. As a result, the composition of the thin film resistor changes and the characteristic of the resistance value of the thin film resistor fluctuates.

In particular, in a thin film temperature sensor having a structure in which a thin film resistor is thermally insulated from other regions on the substrate by forming a through-hole in the substrate and forming a cross-linking structure as described in Patent Document 1, By irradiating the thin film resistor with a laser, the cross-linked structure of the substrate is damaged, and there is a problem that it is difficult to obtain a desired resistance value characteristic.
JP-A-8-271332

  The present invention has been made in consideration of the above circumstances, and the purpose thereof is a voltage output configuration having three terminals in which a thermistor and a resistor are combined, and the characteristics of the resistance value of the thermistor formed on the heat insulating portion are as follows: Thin film temperature sensor capable of realizing highly accurate output characteristics (voltage / temperature) without changing the thermistor characteristics by adjusting with trimmable resistors formed outside the heat insulating part, and its characteristic adjusting method Is to provide.

  The invention according to claim 1 is an insulating first substrate, a through hole formed in the first substrate by penetrating the first substrate, and the first substrate by the through hole. A heat insulating portion that is a region thermally insulated from other regions, a heat-sensitive resistor portion formed in a region on the heat insulating portion of the first substrate, and the first substrate are mounted. An insulating second substrate; a resistor portion formed on the second substrate, the resistance value of which can be adjusted by trimming; and a resistor portion formed on the second substrate, A first terminal electrode electrically connected to one terminal, formed on the second substrate, and electrically connected to the other terminal of the resistor portion and one terminal of the thermal resistor portion. A second terminal electrode formed on the second substrate and electrically connected to the other terminal of the thermal resistance portion. A thin film temperature sensor and having a third terminal electrode to be continued.

  According to a second aspect of the present invention, an insulating substrate, a through hole formed in the substrate by penetrating the substrate, and the other region of the substrate are thermally insulated by the through hole. One terminal formed on a region on the heat insulating portion of the substrate, a first to third terminal electrodes formed in a region outside the heat insulating portion of the substrate, and a region on the heat insulating portion of the substrate. Is electrically connected to the first terminal electrode, and the other terminal is electrically connected to the second terminal electrode, and a region outside the thermal insulating part on the substrate. One terminal is connected to the second terminal electrode and the other terminal is electrically connected to the third terminal electrode, and the resistance value can be adjusted by trimming. It is a thin film temperature sensor characterized by having a resistance part.

  According to a third aspect of the present invention, in the thin film temperature sensor according to the first or second aspect, the through hole is formed by four slit-shaped holes arranged on four sides of a quadrangle. It is.

  According to a fourth aspect of the present invention, there is provided a thermal resistance portion formed in a region on a thermal insulating portion that is thermally insulated from other regions of the substrate by a bridging structure formed on the substrate, and the thermal insulation. A method of adjusting a resistance value of a thin film temperature sensor having a resistance portion that is formed in a region outside the region and is connected to the thermal resistance portion and capable of adjusting a resistance value by performing trimming. A first step of measuring a resistance value; a second step of determining a resistance value of the resistance portion based on the resistance value of the thermal resistance portion measured in the first step; and the second step. And a third step of adjusting the resistance value by trimming the resistance portion based on the resistance value of the resistance portion determined in (1).

In the present invention, the thermal resistance portion is formed on the thermal insulation portion of the first substrate, thereby thermally insulating the thermal resistance portion from the outside, and by trimming between the thermal resistance portion and the first terminal electrode. A resistor capable of adjusting the resistance value is connected.
For this reason, by adjusting the resistance value of the resistance portion by trimming, it is not necessary to adjust the resistance value of the thermal resistance portion itself, and the resistance value can be adjusted with high accuracy without changing the characteristics of the thermistor. it can.

Further, in the present invention, on the first substrate, a resistance portion whose resistance value can be adjusted is connected in series to the thermal resistance portion, and the first to first ends between and between the thermal resistance portion and the resistance portion. A third terminal electrode was formed respectively.
For this reason, it is not necessary to adjust the resistance value of the thermosensitive resistor itself by adjusting the resistance value of the resistance part that can adjust the resistance value, and the resistance value is highly accurate without changing the characteristics of the thermistor. Adjustments can be made. In addition, since the thin film temperature sensor is formed on the first substrate, the size can be reduced and the handling can be facilitated.

In the present invention, the through hole is formed by four slit-like holes arranged on four sides of the quadrangle.
For this reason, it is possible to prevent heat from flowing from a region outside the thermal insulation portion of the substrate into the thermal resistance portion formed on the region of the thermal insulation portion surrounded by the slit, and the thermal resistance portion and the substrate. It is possible to increase the thermal resistance between the two and reduce the heat capacity of the heat-sensitive resistor portion formed on the region of the heat insulating portion.

Moreover, in this invention, after measuring the resistance value of a thermal resistance part, the resistance part which can adjust a resistance value was adjusted.
For this reason, it is not necessary to adjust the resistance value of the heat-sensitive resistor portion, and for example, when adjusting the resistance value by laser trimming or the like for the heat-sensitive resistor portion formed on the heat insulating portion via the bridge structure. Can be prevented from being damaged.

Hereinafter, thin film temperature sensors 10a and 10b according to embodiments of the present invention will be described with reference to the drawings.
FIG. 2 is a plan view showing the structure of the thin film temperature sensor 10a according to the first embodiment of the present invention. In the thin film temperature sensor 10a according to the present embodiment, terminal electrodes 2a, 2b, 2c, a resistance portion 3a, and a thermal resistance portion 4 are formed on a substrate 1a.

The resistance portion 3a is a thin film resistor or a thick film resistor whose resistance value can be adjusted by performing trimming by laser irradiation or the like. Thus, since it is set as the electric power output structure which has three terminals which combined the thermistor and resistance, dispersion | variation in the characteristic of the resistance value of the thermosensitive resistance part 4 is attained by using the resistance part 3a which can adjust resistance value. Even if it exists, it becomes possible to manufacture the thin film temperature sensor 10a of uniform quality by adjusting the resistance value of the resistance part 3a by trimming.
In the thermal resistor 4, terminal electrodes 5 a and 5 b, a thin film thermistor 6, comb electrode patterns 7 a and 7 b, and wiring patterns 8 a and 8 b are formed on the substrate 1 b. Further, through holes 9a to 9d penetrating the substrate 1b are formed in the substrate 1b of the thermal resistance portion 4.
Hereinafter, the structure of the substrate 1b of the thermal resistor 4 will be described with reference to FIG.

FIG. 3 is a plan view showing the shape of the substrate 1 b used in the thermal resistor 4. The substrate 1b is formed with through holes 9a to 9d penetrating the substrate plane in the vertical direction. In order to form the through holes 9a to 9d in the substrate 1b, the substrate 1b is processed by deep etching using a micromachining technique or the like.
By forming such through-holes 9a to 9d in the substrate 1b, the thermal insulating portion 12 at the center of the substrate is connected to a region outside the thermal insulating portion 12 of the substrate 1b only through the bridging structures 11a to 11d. . Therefore, it is possible to prevent heat from being transferred into the heat insulating portion 12 from the region outside the heat insulating portion 12 of the substrate 1b through the through holes 9a to 9d.

A circuit as shown in FIG. 2 is formed on the substrate 1b described with reference to FIG. That is, the terminal electrode 5a and the thin film thermistor 6 are electrically connected to the upper surface of the square thin film thermistor 6 via the wiring pattern 8a and the comb electrode pattern 7a.
The terminal electrode 5b and the thin film thermistor 6 are electrically connected to the upper surface of the thin film thermistor 6 through the wiring pattern 8b and the comb electrode pattern 7b. Since the comb electrode patterns 7a and 7b have a comb shape, the distance between the counter electrodes can be reduced, while the area can be increased and the resistance can be reduced.

FIG. 4 is a cross-sectional view showing the structure of the thermal resistor 4 according to this embodiment.
A through hole 9 is formed in the substrate 1b. A support layer 13 is formed on the substrate 1b. A buffer layer 14 is formed on the support layer 13. A thin film thermistor 6 is formed in a region on the heat insulating portion 12 (FIG. 3) on the buffer layer 14. The thin film thermistor 6 is formed using a transition metal oxide such as Mn, Co, Fe, or Al by a sputtering method or the like.

Comb electrodes 7 a and 7 b are formed on the thin film thermistor 6. Further, terminal electrodes 5a and 5b are formed in a region on the buffer layer 14 outside the heat insulating portion 12 (FIG. 3). As the material of the terminal electrodes 5a and 5b, Au (gold) or the like is used.
The thin film thermistor 6 formed in the region on the thermal insulating portion 12 (FIG. 3) of the substrate 1b and the terminal electrodes 5a and 5b formed in the region outside the thermal insulating portion 12 of the substrate 1b are bridge structures 11a to 11d. (FIG. 3) They are electrically connected via wirings 8a and 8b formed thereon.

A protective film 15 is formed on the substrate 1b so as to cover the comb electrode patterns 7a and 7b and the wiring patterns 8a and 8b. By forming the protective film 15, the thin film thermistor 6 is electrically insulated from the outside.
The substrate 1b is formed with bridging structures 11a to 11d, and is weak against external impacts, so that it is sealed with a package (not shown) so as to cover the substrate 1b.

As shown in FIG. 2, the above-described thermal resistance portion 4 is mounted on the substrate 1a of the thin film temperature sensor 10a. The terminal electrode 2c of the thin film temperature sensor 10a and the terminal electrode 5a of the thermal resistor 4 are electrically connected via a wiring pattern 8c.
Further, the terminal electrode 2b of the thin film temperature sensor 10a, one terminal of the resistor portion 3a, and the terminal electrode 5b of the heat sensitive resistor portion 4 are electrically connected to each other via a wiring pattern 8d. Furthermore, the other terminal of the resistance portion 3a is electrically connected to the terminal electrode 2a of the thin film temperature sensor 10a via the wiring pattern 8e.

When the thin film temperature sensor 10a according to the present embodiment is used to measure the temperature detected by the thin film temperature sensor 10a, the terminal electrode 2c is grounded and a voltage is applied to the terminal electrode 2a. Since the resistance value of the thin film temperature sensor 10a varies depending on the detected temperature, the voltage output from the terminal electrode 2b also varies accordingly.
Therefore, the ambient temperature of the thin film temperature sensor 10a can be calculated by storing the voltage output from the terminal electrode 2b and the temperature detected by the temperature sensor 10a in association with each other.

FIG. 5 is an equivalent circuit diagram of the thin film temperature sensor 10a (FIG. 2) according to the present embodiment.
The input terminal electrode 21, the output terminal electrode 22, the ground terminal electrode 23, the resistor 24, and the NTC · 25 in FIG. 5 are the terminal electrode 2c, the terminal electrode 2b, the terminal electrode 2a, the resistance portion 3a of the thin film temperature sensor 10a in FIG. Each corresponds to the heat-sensitive resistance portion 6.
NTC (Negative Temperature Coefficient) · 25 is a thermistor whose resistance value decreases as the temperature rises. By applying a voltage between the input terminal electrode 21 and the ground terminal electrode 23 and measuring the voltage between the output terminal electrode 22 and the ground terminal electrode 23, the output voltage is converted into a temperature and a temperature change is detected. can do.

In the present embodiment, the thin film thermistor 6 formed on the heat insulating portion 12 is trimmed with a laser without trimming with a laser, and the thin film temperature is reduced by trimming the resistance portion 3a formed in a region outside the heat insulating portion 12 with a laser. The resistance value of the sensor 10a was adjusted.
Therefore, in the process of adjusting the resistance value of the thin film temperature sensor 10a using the laser, the thin film thermistor 6 formed on the thermal insulating portion 12 is not damaged, and the resistance value characteristic of the thin film thermistor 6 changes. Can be prevented.

Further, in the thin film temperature sensor 10a (FIG. 2) according to the present embodiment, the resistance portion 3a and the thermal resistance portion 4 are connected in series, the voltages at both ends thereof are measured by the terminal electrodes 2a and 2c, and the resistance portion 3a and the thermal sensitivity are measured. A three-terminal configuration in which the voltage between the resistance portions 4 can be measured by the terminal electrode 2b is adopted.
Therefore, compared with a two-terminal temperature sensor that measures the voltage by measuring the voltage across the resistor part 3a and the thermal resistor part 4 connected in series and measuring the change in resistance value, it is handled by signal processing. It is possible to provide a temperature sensor that is easy to handle.

Next, a thin film temperature sensor 10b according to a second embodiment of the present invention will be described.
FIG. 1 is a plan view showing the structure of the thin film temperature sensor 10b according to the present embodiment. In the description of the present embodiment, portions having the same configuration as the thin film temperature sensor 10b of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
In the thin film temperature sensor 10a (FIG. 2) according to the first embodiment, the thin film thermistor 6 is formed on the substrate 1b, and the resistance portion 3a is formed on the substrate 1a. Further, the voltage is detected from the thin film temperature sensor 10a using the terminal electrodes 2a, 2b, and 2c formed on the substrate 1a.

  However, in the thin film temperature sensor 10b (FIG. 1) according to the second embodiment, the substrate 1a is not used, and the thin film thermistor 6 and the resistance portion 3b are formed on the substrate 1b. Moreover, the voltage is detected from the thin film temperature sensor 10b using the terminal electrodes 5a, 5b, and 5c formed on the substrate 1b. In this respect, the thin film temperature sensors 10a and 10b according to the first embodiment and the second embodiment are different.

  As shown in FIG. 1, both ends of the resistance portion 3 of the thin film temperature sensor 10b of this embodiment are connected to terminal electrodes 5b and 5c, respectively. In order to adjust the characteristics of the resistance portion 3, slits are formed by laser trimming in a plurality of locations in a direction perpendicular to the longitudinal direction of the resistance portion 3. FIG. 1 shows a case where four slits are formed in the resistance portion 3 by laser trimming.

When the thin film temperature sensor 10b according to the present embodiment is used to measure the temperature detected by the thin film temperature sensor 10b, the terminal electrode 5c is grounded and a voltage is applied to the terminal electrode 5a. Since the resistance value of the thin film temperature sensor 10b varies depending on the detected temperature, the voltage output from the terminal electrode 5b also varies accordingly.
Therefore, the temperature around the thin film temperature sensor 10b can be calculated by storing the voltage output from the terminal electrode 5b and the temperature detected by the temperature sensor 10a in association with each other.

The equivalent circuit diagram of the thin film temperature sensor 10b according to the present embodiment is the same as the equivalent circuit diagram (FIG. 5) of the thin film temperature sensor 10a according to the first embodiment.
The input terminal electrode 21, the output terminal electrode 22, the ground terminal electrode 23, the resistor 24, and the NTC · 25 in FIG. 5 are the terminal electrode 5a, the terminal electrode 5b, the terminal electrode 5c, and the thin film resistor 3b of the thin film temperature sensor 10b in FIG. Each corresponds to the thin film thermistor 6.
By applying a voltage between the input terminal electrode 21 and the ground terminal electrode 23 and measuring the voltage between the output terminal electrode 22 and the ground terminal electrode 23, the output voltage is converted into a temperature and a temperature change is detected. can do.

  According to the thin film temperature sensor 10b according to the present embodiment, the resistance part 3b and the heat-sensitive resistance part 6 formed on the thermal insulating part 12 of the substrate 1b are formed on one substrate 1b. Therefore, it is easier to handle than the thin film temperature sensor 10a according to the first embodiment, and the thin film temperature sensor 10b can be downsized.

According to the thin film temperature sensors 10a and 10b according to the first and second embodiments described above, it is not necessary to trim the thin film thermistor 4 in order to adjust the resistance value, and only trimming of the resistance portions 3a and 3b is performed. Good. Therefore, it is possible to prevent the thin film thermistor 4 from being damaged when performing trimming to adjust the resistance value.
This is particularly effective when the thin film thermistor 4 is formed on the thermal insulating portion 12 that is structurally vulnerable to shock, like the thin film temperature sensors 10a and 10b according to the embodiment of the present invention.
In addition, since the resistance value is adjusted while trimming the thermal resistance portion, the resistance value is changed by irradiating the thermal resistance portion with a laser, and it is difficult to accurately adjust the characteristic of the resistance value. There was a problem, but such a problem can be solved.

  In addition, although this embodiment demonstrated the case where the through-holes 9a-9d have four slit-shaped holes arrange | positioned on four sides of a rectangle, it is not limited to this. That is, as long as it is possible to thermally insulate the thermal insulating portion 12 from the region outside the thermal insulating portion 12 of the substrate 1b, various shapes and numbers of through holes and various methods for arranging the through holes on the substrate 1b are available. The shape, number, and arrangement method can be used.

  The embodiments of the present invention have been described above with reference to the drawings. However, specific configurations are not limited to these embodiments, and design changes and the like within a scope not departing from the gist of the present invention are possible. Is possible.

  The method for adjusting a thin film temperature sensor of the present invention can be used for accurately adjusting the resistance value characteristic of a non-contact temperature sensor used for infrared detection or the like.

It is a top view which shows the structure of the thin film temperature sensor 10b by the 2nd Embodiment of this invention. It is a top view which shows the structure of the thin film temperature sensor 10a by the 1st Embodiment of this invention. It is a top view which shows the structure of the board | substrate of the thermal resistance part 4 of this embodiment. It is sectional drawing which shows the structure of the thermal resistance part 4 of this embodiment. It is an equivalent circuit schematic of thin film temperature sensor 10a, 10b by embodiment of this invention.

Explanation of symbols

1a, 1b ... Substrates 2a-2c ... Terminal electrodes 3a, 3b ... Resistor 4 ... Thermal sensitive resistors 5a, 5b ... Terminal electrode 6 ... Thin film thermistors 7a, 7b ... Comb electrode patterns 8a to 8e ... wiring patterns 9, 9a to 9d ... through holes 10a, 10b ... thin film temperature sensors 11a to 11d ... bridging structure 12 ... thermal insulation part 13 ... Support layer 14 ... Buffer layer 15 ... Protective film 21 ... Input terminal electrode 22 ... Output terminal electrode 23 ... Earth terminal electrode 24 ... Resistance 25 ... NTC

Claims (4)

An insulating first substrate;
A through hole formed in the first substrate by penetrating the first substrate;
A thermal insulating part that is a region thermally insulated from the other region of the first substrate by the through hole;
A thermal resistance portion formed in a region on the thermal insulation portion of the first substrate;
An insulating second substrate on which the first substrate is mounted;
A resistance portion formed on the second substrate and capable of adjusting a resistance value by performing trimming;
A first terminal electrode formed on the second substrate and electrically connected to one terminal of the resistor;
A second terminal electrode formed on the second substrate and electrically connected to the other terminal of the resistance portion and one terminal of the thermal resistance portion;
A third terminal electrode formed on the second substrate and electrically connected to the other terminal of the thermal resistance portion;
A thin film temperature sensor characterized by comprising: An insulating substrate;
A through hole formed in the substrate by penetrating the substrate;
A thermal insulating part that is a region thermally insulated from the other region of the substrate by the through hole;
First to third terminal electrodes formed in a region outside the thermal insulating portion of the substrate;
Formed in a region on the thermal insulating portion of the substrate, one terminal is electrically connected to the first terminal electrode, and the other terminal is electrically connected to the second terminal electrode; A thermal resistance part;
Formed in a region outside the thermal insulating portion on the substrate, one terminal is connected to the second terminal electrode, and the other terminal is electrically connected to the third terminal electrode to perform trimming. A resistance part capable of adjusting the resistance value by performing,
A thin film temperature sensor comprising:   3. The thin film temperature sensor according to claim 1, wherein the through hole is formed by four slit-like holes arranged on four sides of a quadrilateral. A thermal resistance part formed in a region on a thermal insulation part thermally insulated from other areas of the substrate by a bridging structure formed on the substrate; and the thermal resistance part formed in a region outside the thermal insulation part Is a resistance value adjustment method of a thin film temperature sensor having a resistance portion capable of adjusting a resistance value by performing trimming,
A first step of measuring a resistance value of the thermal resistance portion;
A second step of determining a resistance value of the resistance portion based on the resistance value of the thermal resistance portion measured in the first step;
A third step of adjusting the resistance value by trimming the resistance portion based on the resistance value of the resistance portion determined in the second step;
A method of adjusting characteristics of a thin film temperature sensor, comprising:

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