JPH08292202A - Detector - Google Patents

Abstract

PURPOSE: To improve precision in detecting atmosphere by preventing a heat generator pattern from causing temperature ununiformity due to temperature difference from a substrate. CONSTITUTION: Relating to an atmosphere sensor of microbridge structure, a cavity part 3 is provided at the center of a substrate 1 on the top face of which a thin film resistor 2 is formed, and a thin film resistor 2a on the cavity 3, a heat generator pattern 4, and a lead out wiring pattern 5, connected at a contact part 6 to the outer most peripheral part of the pattern 4 from the outer side of the heat generator pattern 4 to further outside, are bridge with a supporting part 2b, and, the detection error caused when the temperature of the heat generator pattern 4 between the lead out wiring patterns 5 is uniform in distribution and the temperature distribution of the heat generator pattern 4 is ununiform is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detector, and more particularly, to a specific gas contained in an atmosphere, a flow rate and a flow rate of the atmosphere, or a thermal change due to the temperature of the atmosphere and the amount of received infrared rays. The present invention relates to a heat conduction type gas detection device, an infrared ray, and a temperature sensor, which have a signal extraction wiring pattern provided so as to detect a change in resistance value and prevent a detection signal from being affected by ambient temperature.

[0002]

2. Description of the Related Art Humidity sensors, gas sensors, flow sensors, and other atmosphere sensors having a micro-bridge structure utilizing the principle of heat conduction, and temperature sensors each have a heat-generating portion or a heat-receiving portion. Detection of physical quantity such as gas component, concentration, etc., physical quantity such as flow rate, humidity, etc. selectively and with high sensitivity, and detection of physical quantity such as atmosphere temperature, infrared ray quantity, etc. from resistance change of heat receiving part It is a device. However, since the heat generating portion of the sensor is an object having a heat capacity made of a heat conductive substance, there is a temperature distribution caused by the heat flow, and it is impossible to control the temperature of all the heat generating portions to the target constant temperature. Have difficulty.

For example, in the case of a gas sensor having a gas sensitive substance composed of a metal oxide semiconductor such as SnO ₂ , ZnO, Fe ₂ O _3, ..., When the gas sensor is used to selectively detect ethanol or isobutane, The temperature of the substance is 250 to 350 in the case of ethanol detection.
(° C), temperature for isobutane detection is 350-450
It is specified in the range of (℃).

It is difficult to control so as to maintain the temperature in such a range with the structure in which the heat generating part and the detecting part are integrated, and it is necessary to combine the heat generating part and the indirect heater. However, the indirectly heated heater itself has a temperature distribution, for example, even if the temperature is 400 ° C. at the central position, 100 at the end.
At ° C, a large temperature deviation occurs between the center and the end. If the temperature distribution of the sensing part made of sensitive material is large as described above, it becomes impossible to select and detect ethanol and isobutane. When used as a gas leak alarm for LP (liquefied petroleum) gas, However, there is a problem that the reliability of the alarm is impaired because the gas leak alarm is issued.

In order to solve the adverse effect on the detection accuracy due to the non-uniform temperature distribution of the detecting portion, the present applicant has
The "detector structure of the detector" disclosed in JP-A-6-174672 and the "atmosphere detector" disclosed in JP-A-62-220850 have been proposed.

In the detector structure according to JP-A-6-174672, an overhanging portion of an electrically insulating material is provided so as to overhang in the air on the substrate, and a sensitive material is provided on the overhanging portion where the temperature distribution is uniform. The structure is provided with an opening so that no sensitive substance other than the sensitive substance in the opening is brought in.

In the atmosphere detecting device according to Japanese Patent Laid-Open No. 62-220850, a film of an electrically insulating material is cross-linked on the concave portion formed on the substrate, and the cross-linked thin film insulator is formed.
A heater member that extends in the longitudinal direction and a detection member that extends in parallel with the heater member and that is substantially center-separated from each other are provided. Furthermore, a gas-sensitive sensor is provided between the separated portion of the detection member and the central portion of the heater member. The material is laminated, and the shape of the heater is devised so that the temperature distribution of the sensitive material is constant.

Further, in the case of a sensor having a structure and principle in which the heat generating part and the detecting part are not separately constructed but the heat generating part and the detecting part are used in common, the heat generating part itself has a temperature distribution because of the structure. However, there is a problem that the influence of this temperature distribution appears on the detection characteristics.

The type of sensor having the structural principle that serves both as a heat generating portion and a detecting portion is as follows: (1) A method in which the heat generation temperature is affected by a change in the heat conduction of the surrounding atmosphere and is detected as a change in the resistance value of the heating element. Humidity sensor, dew condensation sensor, gas maroma kraft. (2) A method of detecting as a change in the resistance value of the heating element caused by heat according to the amount of the atmosphere around the heating element flowing,
Wind speed sensor and flow rate sensor. (3) A temperature sensor that detects the ambient temperature around the resistor as the resistance value of the resistor, an infrared sensor that converts the temperature raised by the heat generated by receiving infrared rays into an electrical signal by the resistor, semiconductor, thermoelectric body, etc. . Etc. Among these atmosphere sensors, a conventional humidity sensor will be described as a representative.

FIG. 7 is a structural view for explaining an example of a conventional humidity sensor, FIG. 7 (A) is a plan view, and FIG.
7B is a sectional view taken along the line BB of FIG.
Reference numeral 1 is a substrate, 42 is an insulating thin film, 43 is a recess, and 44 is a heating resistor.

The humidity sensor shown in FIG. 7 is an example of a self-temperature compensation type humidity sensor.
When heated at low power, the humidity dependence is small, and the resistance value depends on the ambient temperature. When heated at high power, the humidity,
It is a humidity sensor that obtains the humidity by subtracting the temperature-dependent component by utilizing the fact that it changes according to the temperature. In this humidity sensor, an insulating thin film 42 of tantalum oxide (Ta ₂ O ₅ ) is formed on a substrate 41 made of rectangular silicon Si (100), and then anisotropically etched to form a rectangular recess 43 and a recess 43 on the recess 43. Forming a square insulating thin film 42a having a side parallel to the diagonal line and cross-linked by the supporting portion 42b.
A heat generating resistor 44 made of a zigzag platinum film or the like having pad portions 44a and 44b is formed on the film 1, and a silicon oxide (SiO ₂ ) film is formed on the heat generating resistor 44. As the dimensions, for example, the thickness t between the insulating thin films sandwiching the heating resistor 44 is 3 μm, and the length N (between X and X ₄ ) between the leads 44 c of the heating resistor 44 on the recess 43 is about 3.
00 μm, the length between the diagonal lines M (X _{2 to} X ₃ ) is 260 μm
Is.

FIG. 8 shows the humidity sensor shown in FIG.
A is a diagram showing the temperature distribution of the heating resistor when an electric power of 3.5V is applied, where the horizontal axis is the position of the heating resistor 44 and the vertical axis is the temperature.

As shown in FIG. 8, the heating resistor 44 provided on the recess 43 of the temperature sensor shown in FIG.
The temperature distribution when heated with electric power of 3.5 V is 100 to 50 in the range of the diagonal line (X _{2 to} X ₃ ) of the heating resistor 44.
Although it has a temperature distribution of 0 (° C.), it is continuously decreased from 100 ° C. to room temperature between the leads 44 a (X _{1 to} X ₂ ) and (X _{3 to} X ₄ ). Next, the relationship between the humidity (absolute humidity) related to the temperature of the heating resistor 44 and the heating conductivity will be described.

FIG. 9 is a diagram for explaining an example of the relationship between the absolute humidity and the thermal conductivity with respect to the ambient temperature (The 42nd Japan Society of Applied Physics Association Joint Lecture Paper [Micro-heater temperature sensor using self-temperature compensation method ( 2)] (March 28, 1995)
~ 31 days)), the horizontal axis represents absolute temperature (g / m ³ ) and the vertical axis represents thermal conductivity (W / mk). As shown in FIG. 9, the thermal conductivity is affected by the ambient temperature, and when the ambient temperature is 773 ° k (500 ° C.), the absolute humidity is 0 to 200.
Within the range of (g / m ³ ), the thermal conductivity is 540 × 10 ^{−4 to} 6
Although changing to 50 × 10 ⁻⁴ (W / mk), when the ambient temperature is 473 ° k (200 ° C.), the absolute humidity is a substantially constant value of 380 × 10 ⁻⁴ (W / mk).

Humidity detection by the humidity sensor is a mechanism in which the heating resistor 44 heats a humidity atmosphere in the vicinity to a temperature substantially the same as that of the heating resistor 44, and performs heat exchange and heat conduction with the atmosphere. Therefore, the temperature itself of the heating resistor 44 is reflected in the detection output sensitivity.

FIG. 10 is a diagram for explaining a conventional flow sensor, FIG. 10 (A) is a plan view, and FIG. 10 (B) is FIG.
It is the BB sectional view taken on the line of 0 (A), 51 is a board | substrate, 52 is a thin film insulator, 53 is a groove | channel, 54 is a slit, 5 is a figure.
Reference numerals 5 and 57 are detection units, and 56 is a heater unit.

In the flow rate sensor shown in FIG. 10, a groove 53 having a uniform width is provided in the center of the rectangular substrate 51 having a thin film insulator 52 on the surface in the long side direction, and the thin film insulator 5 in the central portion of the groove 53.
2 has a pair of detecting portions 55, 57 provided along the groove 53.
And the slits 5 each having a predetermined width L with respect to the detection units 55 and 57.
It is sandwiched by 4 and composed of a heater portion 56 and the like.

The heater section 57 of the flow rate sensor shown in FIG.
Is heated with a predetermined constant electric power, and when the gas flows in the direction of arrow F, the gas flowing through the groove 53 is
It flows out through the detector 55, the heater 56, and the detector 57. At this time, the detection unit 55 detects the temperature of the inflowing gas as a resistance value, but the detection unit 57 is heated by heat conduction from the gas flow heated by the heater unit 56, and exhibits a resistance value according to the flow and is detected. The flow rate of the gas is measured from the resistance difference between the parts 55 and 57.

[0019]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
No. 0850, Japanese Unexamined Patent Publication No. 6-174672, and FIG. 7 and FIG.
A thin-film insulator that is bridge-supported or cantilever-supported in the cavity or groove of a heat-conductive substrate such as Si, and has a heat-generating portion on the thin-film insulator on the cavity, or adjacent to the heat-generating portion and the heat-generating portion. There is a detection section provided, and the heating section and the pad section of the detection section pattern are provided on the substrate via a bridge or a cantilever support section.

The atmosphere sensor has a method in which the heat generating portion and the detection are combined, or a method in which the heat generating portion and the detection portion are separated. In either case, the detection is performed with high sensitivity and high accuracy. In order to do so, the temperatures of the heat generating part and the detecting part must have a uniform distribution. However, leads are connected between the substrate and the detection unit and heating unit provided on the cavity or groove of the substrate, and there is a temperature gradient between them. A resistor having a large temperature resistance coefficient is used for the detection unit and the heating unit in order to improve thermal efficiency and high sensitivity. Inevitably, it is easily affected by the ambient temperature, and it is difficult to obtain a uniform temperature distribution. The atmosphere detection device according to Japanese Patent Laid-Open No. Sho 62-220850 and the detector structure of the detector according to Japanese Patent Laid-Open No. 6-174672 have a structure for making the temperature distribution of the detector uniform, but in any case, the detector is on the lead. The detection unit provided and the substrate are separated from each other, and a temperature gradient occurs between them. However, the above-mentioned proposal does not cancel the influence of the temperature gradient. Also, in the case of an infrared sensor having a microbridge structure using the principle of a bolometer or a thermopile, or a temperature sensor, there is a similar problem of temperature distribution.

The present invention has been made to solve the above-mentioned problems, and improves the detection sensitivity and accuracy by setting the signal detection positions of the heating section or the detection section as the both end areas of the pattern having a uniform temperature distribution. The purpose is.

[0022]

In order to solve the above problems, the present invention provides (1) a thin film layer containing a heating element pattern,
In the substrate bridge-supported or cantilevered supported on the cavity,
Leading wiring patterns connected to both ends of the heating element pattern are provided, and a signal is detected between the leading wiring patterns. Further, (2) in (1), the heating element pattern is used. The lead-out wiring pattern is electrically connected on the cavity of the substrate, and further, (3) the (1) or (2).
In the above, the lead-out wiring pattern is made of a material having a smaller heat capacity than the leads of the heating element pattern for driving the heating element pattern to heat it, and a material having a small thermal conductivity, further, (4) above (1) Alternatively, in (2) or (3), the heating temperature of the heating element pattern is detected as a change in the thermal conductivity of the ambient atmosphere or a change in heat transfer depending on the flow rate of the ambient atmosphere as a resistance change of the heating element pattern. A humidity sensor, a condensation sensor, a gas chromatograph, or a wind speed sensor, a flow rate sensor, and (5) In (1), (2), or (3), the ambient temperature or infrared rays is received to receive the ambient temperature. The temperature sensor or the infrared sensor is detected as a resistance value in which the resistance value of the heating element pattern changes.

[0023]

In the atmosphere sensor of the microbridge structure in which the heating element pattern is provided on the thin film insulator which is bridge-supported or cantilevered on the cavity formed in the semiconductor substrate, the heating element is heated when the heating element pattern is heated. In addition to the leads for heating the heating element pattern, in addition to the leads for heating the heating element pattern, the temperature and temperature of the heating element pattern should not be deteriorated so that the sensitivity and accuracy may not deteriorate. The other lead is connected to detect the signal of the heating unit (or the detection unit) having a uniform temperature.

[0024]

【Example】

Example 1 (corresponding to claim 1) FIG. 1 is a plan view for explaining an example of a detection device according to the present invention. In the figure, 1 is a substrate, 2 is a thin film insulator, 3 is a cavity, and 4 is a cavity. A heating element pattern, 5 is a lead wiring pattern, and 6 is a connecting portion.

The detection device shown in FIG. 1 is a humidity sensor of the self-temperature compensation type shown in FIG. 7 provided with a lead-out wiring pattern 5 according to the present invention.
0) After forming the thin film insulator 2 on the upper surface of the substrate 1, vapor deposition, CVD (Chemical Vapor Deposition) on the thin film insulator 2,
An oxidation-stable metal such as platinum (Pt) for forming the heating element pattern 4 is formed by a method such as sputtering. Next, a rectangular thin film insulator 2a and a bridge portion 2b are formed on the cavity 3 by photolithography, anisotropic etching, or the like.

The thin film insulator 2a is provided with a zigzag heating element pattern 4 parallel to the sides of the rectangular thin film insulator 2a, and both ends of the heating element pattern 4 are pad portions 4c provided on the substrate 1, respectively. It is connected to 4d. The lead-out wiring pattern 5 is arranged at a position further outside the outermost circumference of the heating element pattern 4, and heat is generated at the contact portion 6 at a position where the outermost circumference side of the heating element pattern 4 intersects with the previous outer circumference side. A pad portion 5a is provided in the vicinity of the pad portion 4c on the substrate 1 so as to be connected to the body pattern 4. Similarly, the lead-out wiring pattern 5 is provided at a position further outside the outermost peripheral side of the heating element pattern 4 on the side of the pad portion 4d, and the pad portion 4d is provided near the pad portion 4a on the substrate 1. Also, the pad portions 5a, 5
Leads A, B, C, and D are connected to b, 4c, and 4d, respectively.

FIG. 2 is a block circuit for explaining an example of the drive detection circuit of the detection device shown in FIG. 1. In the figure, 7 is a heater power supply, 8 is a detection circuit, and the same operation as in FIG. The same reference numerals as in the case of FIG.

The heater power source 7 is, for example, a constant current power source and is connected to the leads C and D of the heating element pattern 4 of the detecting device.
The heating element pattern 4 is driven to be heated. The detection circuit 8 is connected to the leads A and B of the lead-out wiring pattern 5 and detects the voltage signal between the leads A and B.

When the detection device shown in FIG. 1 is connected to the drive detection circuit of FIG. 2, almost no current flows between the leads A and B, but the lead wiring pattern 5 includes the heating element pattern 4 and the contact portion 6. Since they are connected, the temperature of the contact portion 6 is substantially equal to the temperature of the heating element pattern 4, and the uniform temperature distribution between the contact portions 6 defined as the uniform heat distribution region is not impaired. Dependence is relatively small and higher sensitivity characteristics can be obtained. In addition, section (A
Since the detection regions (1) to (B) are separated from the substrate 1 having a large heat capacity, they are less affected by the temperature of the substrate 1 and the temperature and humidity of the atmosphere can be detected more accurately with a fast response.

Embodiment 2 (corresponding to claim 2) FIG. 3 is a plan view for explaining another embodiment of the detection device according to the present invention, in which 9 is a lead wiring pattern, and FIG. The same reference numerals as in the case of FIG.

The detection device shown in FIG. 3 is arranged further outside the outermost circumference of the square heating pattern 4 in which the lead-out wiring pattern 9 according to the first embodiment shown in FIG. 1 is arranged on the cavity 3. While the thin film insulator 2 supporting the heating element pattern 4 reaches the pad portions 5a and 5b from the supporting portion 2b side and is patterned, the embodiment 2 shown in FIG.
The lead-out wiring pattern 9 is electrically connected to the heating element pattern 4 and the contact portion 6 at the upper portion of the cavity 3, passes through the upper portion of the support portion 2c of the thin film insulator 2, and is provided on the substrate 1 with the pad portion 9a. 9b, the leads A and B on the pad portions 9a and 9b are connected.

FIG. 4 is a diagram for explaining an example of a block circuit for detecting temperature and humidity by using the detection device of FIG. 3, in which 21 is a heater power source, 22 is a temperature / humidity detection unit, and 2 is a unit.
Reference numerals 3 and 24 are temperature detectors.

The leads C and D of the heating element pattern 4 are connected to the heater power source 21, and the leads A and B of the lead wiring pattern 9 are connected to the temperature / humidity detector 22. Further, one lead A of the connected lead-out wiring pattern 9 and one lead C of the heating element pattern 4 are connected to the temperature detecting unit 23, and the connected lead-out and lead-out wiring pattern 9 are connected.
The other lead and the other lead D of the heating element pattern 4 are connected to the temperature detection unit 24.

In FIG. 4, the heater power supply 21 is turned on, and the heater power supply 21 is connected between the leads C and D, for example, 8
When a current of mA flows, a voltage of 3V is generated between the leads A and B, and the leads A and B are heated to a high temperature. At this time, at the same time, a current of 8 mA flows between the leads C-A and B-D and is heated, but since the circuit pattern is short, the resistance is small,
Further, since the leads are on the substrate 1 having a low temperature, the temperature does not rise. Therefore, the temperature detected by the temperature detection units 23 and 24 is in a low temperature state when 4 mA is applied between the leads A and B, and the temperature detection unit 23 or 2 outputs from the output of the temperature / humidity detection unit 22.
The humidity can be obtained by subtracting the temperature of 4 or the average temperature of the temperature detection units 23 and 24.

As described above, the lead-out wiring pattern 9 is connected to the temperature distribution range of the temperature of the heating element pattern 4 above the cavity 3, and is low in the external connection section outside the heating level pattern of the heating element pattern 4. Since it is a resistor and has a small heat capacity, it is possible to detect a physical quantity such as humidity with high accuracy. Furthermore, since the heating pattern 4 is supported on the substrate 1 at four positions, the heating pattern 4 is stable, less affected by external vibration, and the accuracy can be maintained. Next, an example of a flow sensor as an atmosphere sensor other than the humidity sensor will be described.

FIG. 5 is a diagram for explaining a flow rate sensor according to the present invention. In the figure, 11 is a substrate, 12 is a thin film insulator, 13 is a groove, 14 is a slit, and 15 and 17 are flow rate signal detecting portions. , 16 is a heater, 18 is a lead-out wiring pattern for ambient temperature detection, 19 is a lead-out wiring pattern for heater temperature monitoring, and 20 is a lead-out wiring pattern for flow rate detection.

In the flow rate sensor shown in FIG. 5, a groove 13 having a uniform width in the long side direction is provided in the center of a rectangular substrate 11 having a thin film insulator 12 on the surface, and the thin film insulator 12 in the center of the groove 13 is provided.
In addition, a U-shaped flow rate signal detector 15, a heater 16, and a flow rate signal detector 17, which are made of a metal thin film and are sequentially divided by slits 14 from the flow direction arrow F side, are provided. Further, from the vicinity of the opening of the upstream U-shaped flow signal detection unit 15, the ambient temperature detection lead-out wiring pattern 18 is connected, and similarly, the downstream U-shaped flow signal detection unit 1 is also provided.
A flow rate detection lead-out wiring pattern 20 is also connected to each of 7. A heater temperature monitor lead-out wiring pattern 19 is connected to the heater 16.

In the flow rate sensor shown in FIG. 5, first, a heater power source (not shown) is connected to the terminal 16a of the heater 16 to heat the gas flowing in the direction of the arrow F with a constant electric power to heat the heated gas. The signal of the flow rate signal detecting unit 17 which is heated by heat conduction from the above and whose resistance changes according to the flow rate is taken out from the flow rate detecting lead wiring pattern 20. At the same time, heater 1
Due to the heating of No. 6, the ambient temperature flowing without being affected by heat is taken out via the ambient temperature detecting lead-out wiring pattern 18 connected to the flow rate signal detecting unit 15, and based on the difference signal from the flow rate signal detecting lead-out wiring pattern 20. To detect the flow rate.

The flow rate sensor shown in FIG. 5 detects the difference in resistance value proportional to the temperature difference between the flow rate signal detecting units 15 and 17 as a voltage signal. The flow rate signal detecting units 15 and 17 have terminals 15a and 17a respectively. Is provided on the substrate 11 having a temperature difference, the temperature of the flow rate signal detecting portions 15 and 17 near the terminals 15a and 17a is lower than the temperature on the groove 13, and the temperature does not correspond to the flow rate. Although this is a cause of detection error, since the ambient temperature detecting lead-out wiring pattern 18 and the flow rate signal detecting lead-out wiring pattern 20 are respectively joined to the portions of the soaking temperature distribution of the flow rate signal detecting portions 15 and 17, respectively. The above-mentioned error factors are removed, and a highly accurate gas flow rate is detected. The heater temperature 16 can also be monitored by the heater temperature monitor 19 without being affected by the temperature distribution.

As described above, each lead-out wiring portion provided in the atmosphere sensor according to the present invention is connected to the uniform heating range of the heating element pattern or the like, but since it is a non-heating element, the load heat capacity for the heating element pattern is large. Has become. As a result, the lead-out wiring pattern is a factor that lowers the heater temperature near the connection. In order to reduce the heat capacity of such a lead-out wiring pattern and minimize the heat dissipation of the heating element pattern and the like, the lead-out wiring pattern must have the following conditions.

(1) The pattern width and thickness of the lead-out wiring portion are made smaller than that of the heater pattern to reduce the heat capacity. Also,
A current hardly flows in the lead-out wiring pattern, and since the generated voltage can be detected regardless of the allowable current density required for the heater, it is sufficient if it has a conductive function. (2) To reduce the heat flow from the heater, select a material with low thermal conductivity. As the lead-out wiring material, for example, ITO (Indium Tin Oxide) or Ni-C having a thermal conductivity that is one digit smaller than that of a heating element such as W, Mo, Pt, or PtIr.
r, stainless alloy is used (corresponding to claim 3).

The conventional heating element pattern has an extremely thin cross-sectional shape in order to prevent heat from being dissipated from the heating element pattern, and is required to have strength. However, by providing the lead-out wiring pattern as described above, the restrictions required for the heating element pattern described above are alleviated, it becomes possible to design the heating element pattern with a high degree of freedom, and it is possible to further improve the strength of the field. The application will be expanded.

As described above, the lead-out wiring patterns 4, 9, 1
Although the humidity sensor and the flow rate sensor have been described as the atmosphere sensor having 7, 18, and 19, the flow rate sensor is also used as the wind speed sensor. Providing the lead-out wiring pattern can also be applied to other heat conduction type gas detection sensors. For example, the dew state for detecting a condensation state where the relative humidity is close to 100% as a rapid resistance change. In a gas chromatograph, such as a sensor, the gas chromatograph can be used as a detector for a gas chromatograph that detects a gas for detection that has passed through a column by a heat conduction type detection method.
Corresponding to).

An infrared sensor, a temperature sensor, and the like are examples of the detection device having a heat receiving portion. Here, an example of the infrared sensor will be described. FIG. 6 is a diagram for explaining an example of an infrared sensor according to the present invention, FIG. 6 (A) is a plan view, and FIG. 6 (B) is a sectional view taken along the line BB of FIG. 6 (A). In the figure, 31 is a substrate, 32 is a thin film insulator, 33 is a cavity, 34 is a resistor, 35 is a lead wiring pattern, 36
Is an infrared absorption layer.

The infrared sensor shown in FIG.
After forming the thin film insulator 32 on the substrate 31 of 0), the cavity 33 is provided by anisotropic etching, and the circular resistor thin film 32a and the resistor thin film 3 are formed on the cavity 33.
A conductive material having a large temperature coefficient of resistance formed in advance on the insulator thin film 32, for example, a resistor 34 having a circular zigzag structure formed by cross-linking and supporting 2a on the substrate 31 in a cross shape, and Pad portions 34e and 34f are provided on the lead pattern 34a and the substrate 32, and a lead wiring pattern 35 is provided at a position where the lead wiring 34 is bent to the outermost periphery of the circular zigzag structure. The pad portion 35b and the lead wire H are provided. Next, the insulating film 32 such as SiO ₂ is formed on the upper surface of the circular resistor 34, and the infrared absorbing layer 36 such as platinum black of fine black powder platinum is applied on the upper surface thereof.

The infrared sensor shown in FIG. 6 receives infrared rays by the infrared absorption layer 36 and exchanges heat therewith, and detects the amount of infrared rays by the resistance value of the resistor 34 heated by the obtained heat. Although a temperature drop occurs due to heat conduction in the vicinity of the connection between the resistor 34 and the lead 34a on the low temperature side with respect to 34, the lead wiring pattern 35 has a small thermal conductivity and heat capacity, and the temperature distribution of the resistor 34 is uniform. Since it is connected to the region, the amount of heat proportional to the amount of infrared rays absorbed by the infrared absorption layer 36 is absorbed, and accurate infrared detection becomes possible.

Since the thermometer for detecting the temperature from the resistance value of the resistor 34 is constructed by removing the infrared absorption layer shown in FIG. 6, the lead wiring pattern 35 has the same function as that of the infrared sensor. This improves the detection accuracy (corresponding to claim 5).

[0048]

As is apparent from the above description, the present invention has the following effects. Effect corresponding to claim 1: In the atmosphere sensor of the microbridge structure having the heating element pattern, since the lead-out wiring patterns are respectively provided from the both ends having a uniform temperature distribution of the heating element pattern, the heating element pattern on the high temperature side is provided. A highly accurate and highly responsive atmosphere sensor can be obtained without being adversely affected by a temperature difference due to heat conduction between the low temperature side terminal portion and the low temperature side terminal portion. Effect corresponding to claim 2: In addition to the lead pattern of the heating element pattern, the lead-out wiring pattern is connected to the heating element pattern on the cavity 5 provided on the substrate within the uniform heating range of the heating element pattern on the cavity. Therefore, the same effect as that of claim 1 can be obtained, and since the lead pattern of the lead-out wiring pattern can be provided at a position different from the lead pattern of the heating element pattern, the rigidity of the supporting portion is high and the influence of disturbance is less likely to occur. You can Effect corresponding to claim 3: Since the cross-sectional area of the lead-out wiring pattern is made smaller than the cross-sectional area of the heating element pattern to make the heat capacity small and the material having small thermal conductivity,
The heat effect of the lead-out wiring pattern on the heating element pattern is small, and the effect of providing the lead-out wiring pattern is further improved. Effect corresponding to claim 4: With the effects of claims 1 to 3, it is possible to obtain a humidity sensor, a condensation sensor, a gas crosstograph, a flow rate sensor, and an anemometer having high accuracy and excellent responsiveness. Effect corresponding to claim 5: Since the lead-out wiring pattern is provided even for the sensor having the heat receiving part,
It is possible to obtain a highly accurate infrared sensor and temperature sensor that can achieve the same effect as.

[Brief description of drawings]

FIG. 1 is a plan view for explaining an example of a detection device according to the present invention.

FIG. 2 is a block circuit for explaining an example of a drive detection circuit of the detection device shown in FIG.

FIG. 3 is a plan view for explaining another embodiment of the detection device according to the present invention.

FIG. 4 is a diagram for explaining an example of a block circuit that detects temperature and humidity using the detection device of FIG.

FIG. 5 is a diagram for explaining a flow rate sensor according to the present invention.

FIG. 6 is a diagram for explaining an example of an infrared sensor according to the present invention.

FIG. 7 is a structural diagram for explaining an example of a conventional humidity sensor.

8] 8mA, 3.5V for the humidity sensor shown in FIG.
It is a figure showing the temperature distribution of the heating resistor when the electric power of is applied.

FIG. 9 is a diagram showing a relationship between absolute humidity and thermal conductivity with respect to ambient temperature.

FIG. 10 is a diagram for explaining a conventional flow rate sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Insulator thin film, 3 ... Cavity, 4 ... Heating pattern, 5 ... Lead wiring pattern, 6 ... Connection part, 7 ... Heater power supply, 8 ... Detection circuit, 9 ... Lead wiring pattern,
11 ... Substrate, 12 ... Insulator thin film, 13 ... Groove, 14 ... Slit, 15, 17 ... Flow rate signal detection part, 18 ... Atmosphere temperature detection lead line pattern, 19 ... Heater temperature monitor lead line pattern, 20 ... Flow rate detection Lead wire pattern, 21 ... Heater power supply, 22 ... Temperature / humidity detection section, 23, 24
... Temperature detection part, 41 ... Substrate, 42 ... Insulating thin film, 43 ... Recessed part, 44 ... Heating resistor, 51 ... Substrate, 52 ... Insulator film, 53 ... Groove, 54 ... Slit, 55, 57 ... Detection part,
56 ... Heater section.

Claims (5)

[Claims] 1. A substrate in which a thin film layer including a heating element pattern is bridge-supported or cantilevered on a hollow portion, and lead-out wiring patterns connected to the respective ends of the heating element pattern are provided, and the lead-out wiring is provided. A detection device having a structure for detecting a signal between patterns. 2. The detection device according to claim 1, wherein the heating element pattern and the lead-out wiring pattern are electrically connected to each other on the cavity of the substrate. 3. The lead wiring pattern is made of a material having a heat capacity smaller than that of a lead of the heating element pattern for heating and driving the heating element pattern, and a material having a small thermal conductivity. The detection device according to 2. 4. A humidity sensor and a dew sensor for detecting the amount of change in the heat transfer of the heating element pattern according to the change of the thermal conductivity of the surrounding atmosphere or the flow rate of the surrounding atmosphere as the resistance change of the heating element pattern. ,Gas chromatograph,
Alternatively, the detection device according to claim 1, 2 or 3, which is a wind speed sensor or a flow rate sensor. 5. A temperature sensor or an infrared sensor which is detected as a resistance value of a resistance value of the heating element pattern which changes in response to an ambient atmosphere temperature or infrared rays. The detection device according to 1.