JP7093772B2 - Infrared sensor device and its manufacturing method and infrared sensor device unit - Google Patents

Description

The present invention relates to an infrared sensor device, a method for manufacturing the same, and an infrared sensor device unit.

Japanese Patent Application Laid-Open No. 7-209089 (Patent Document 1) and Japanese Patent Application Laid-Open No. 9-264784 (Patent Document 2) include a cap member provided with an infrared transmitting portion for transmitting infrared rays and an infrared ray transmitting portion provided on the cap member. It is provided with an infrared detection sensor element that receives infrared rays transmitted through the portion, one or more temperature compensation sensor elements used for temperature compensation of the output of the infrared detection sensor element, and a substrate with a sensor element that closes the opening of the cap member. Infrared sensor devices are disclosed. Further, in Japanese Patent Publication No. 62-57211 (Patent Document 3), one or more temperature compensation sensor elements used for temperature compensation of the output of an infrared detection sensor element composed of first to third thermistor bolometers and an infrared detection sensor element. However, a radiation thermometer or the like covered with a cap member provided with a light collecting window portion is disclosed.

Japanese Unexamined Patent Publication No. 7-209089 Japanese Unexamined Patent Publication No. 9-264784 Special Publication No. 62-57211

In the conventional infrared sensor device shown in Patent Documents 1 and 2, the infrared rays transmitted through the infrared transmitting portion are reflected in the internal space and hit one or more temperature compensation sensor elements, so that one or more temperature compensation is performed. There was a limit to improving the temperature compensation accuracy by using the output of the sensor element as a reference or compensation.

An object of the present invention is to provide an infrared sensor device having high detection accuracy, a method for manufacturing the same, and an infrared sensor device unit.

The infrared sensor device of the present invention includes a cap member, a substrate with a sensor, and a solder layer for joining the cap member and the substrate with a sensor. The cap member is a first solderable closed loop shape extending along the end face of the peripheral wall portion having an opening on one surface, the facing wall portion facing the opening, and the end surface of the peripheral wall portion surrounding the opening. A pattern is provided, and an infrared transmitting portion that transmits infrared rays is provided on the facing wall portion. The solder layer has a closed loop shape formed along the first joining pattern. The substrate with a sensor includes one or more infrared detection sensor elements that receive infrared rays transmitted through the infrared transmitting portion, and one or more temperature compensation sensor elements used for temperature compensation of the output of the one or more infrared detection sensor elements, and solder. The opening is closed with a second solderable bonding pattern that is bonded to the first bonding pattern by the layer. The internal space surrounded by the cap member and the substrate with the sensor is maintained in a vacuum state. In the present invention, the facing wall portion of the cap member is provided with one or more partition walls that partition the internal space so as to prevent the infrared rays incident from the infrared transmission portion from directly hitting one or more temperature compensation sensor elements . It is provided integrally. A gap is formed between the one or more partition walls and the substrate with the sensor, which blocks the passage of infrared rays incident from the infrared transmitting portion but allows the flow of gas.

According to the present invention, by providing the partition wall, it is possible to prevent infrared rays from directly hitting one or more temperature compensating sensor elements . Since a gap is formed between the upper partition wall and the substrate with the sensor that blocks the passage of incident infrared rays but allows the flow of gas, the adjacent walls are partitioned by the partition wall through this gap. The space can be maintained at the same degree of vacuum. Therefore, except for the condition of being exposed to infrared rays, one or more temperature compensation sensor elements used for temperature compensation of the output of the infrared detection sensor element and the infrared detection sensor element that receive infrared rays transmitted through the infrared transmitting portion should be placed in the same environment. Can be done. As a result, temperature compensation using one or more temperature compensation sensor elements can be realized with high accuracy, and an infrared sensor device with high detection accuracy can be provided.

It is preferable that the end surface of the cap member and the end surface of the free end portion of the partition wall are flush with each other, and the thickness of the gap depends on the thickness of the solder layer. In this way, the thickness of the solder layer defines the dimension of the gap between the end face of the free end of the partition wall and the top surface of the board with the sensor.

The thickness of the solder layer is preferably 100 μm or less. Within this dimensional range, a continuous solder layer that does not cause vacuum leakage can be reliably formed.

One or more temperature compensation sensor elements are an internal space temperature sensor and a reference temperature sensor that measure the temperature of the internal space.

The peripheral wall portion and the facing wall portion of the cap member are a cap body formed of a material containing silicon as a main component and integrally molded, and a solder covering the outer surface of the cap body except for at least an infrared transmitting portion and an inner wall surface of the cap body. It is preferable to use one composed of an attachable metal thin film layer. In this case, the first bonding pattern can be formed by a metal thin film layer. If such a configuration is adopted, the size can be reduced.

A plurality of MEMS sensor elements laminated on a support substrate are provided to form one or more temperature compensation sensor elements, respectively, and the second bonding pattern is formed by a solderable metal thin film layer. It is preferable to have it. According to this configuration, the size can be further reduced.

The thickness of the partition wall is preferably 10 μm or more. The partition wall may have a double structure composed of two wall portions arranged at intervals. With this structure, the total thickness of the partition wall can be reduced and the blocking effect can be enhanced.

In order to enhance the shielding effect, it is preferable to make the wall thickness of the cap member and the partition wall as thick as possible.

When one or more partition walls are composed of two partition walls arranged at a distance, an infrared detection sensor element is placed in a first chamber formed between the two partition walls. An internal space temperature sensor is housed in a second chamber that is housed and is formed between one of the two partition walls and the peripheral wall, and is housed with the other partition wall of the two partition walls. It is preferable that the reference temperature sensor is housed in the third chamber formed between the peripheral wall portion and the peripheral wall portion. By doing so, the change in temperature in the first to third chambers can be made substantially the same.

Further, when one or more partition walls are one partition wall, two infrared detection sensor elements are provided in the first chamber formed between the one partition wall and the peripheral wall portion. A space temperature sensor element and a temperature compensation sensor element are housed in a second chamber formed between a single partition wall and a peripheral wall portion, and two infrared detection sensor elements and a space temperature sensor are housed. As the element and the sensor element for temperature compensation, it is preferable to use an infrared detection element having the same electrical resistance characteristics depending on the temperature. By doing so, the area of the infrared transmitting portion provided for the first chamber can be increased, and the light receiving surface of the two infrared detection sensor elements can be increased. Further, by arranging the same number of sensor elements in the first chamber and the second chamber, the temperature change in the first and second chambers can be substantially the same. Further, it is possible to increase the sensitivity by forming a bridge circuit for the four sensor elements.

It is possible to configure an infrared sensor device unit having four infrared sensor devices and generating an output corresponding to a temperature rise due to infrared rays and an output of an environmental temperature. This infrared sensor device unit consists of a first series circuit in which one of the two infrared detection sensor elements and the space temperature sensor element are electrically connected in series, and the other and the first of the two infrared detection sensor elements. It includes a second series circuit in which the load resistance is electrically connected, and a third series circuit in which the temperature compensation sensor element and the second load resistance are electrically connected in series. One end of the first series circuit to the third series circuit is electrically connected to one output terminal of the DC power supply, and the other end of the first series circuit to the third series circuit is connected to the other output terminal of the DC power supply. It is electrically connected. Then, a signal corresponding to the temperature rise due to infrared rays is output from the midpoint of the first series circuit, and a signal corresponding to the environmental temperature is output from the midpoint of the third series circuit. According to this infrared sensor device unit, it is possible to detect the temperature rise due to infrared rays and the environmental temperature with high accuracy. It is preferable that the first load resistance and the second load resistance have the same resistance value.

In the case of an infrared sensor device unit equipped with an infrared sensor device and generating only the output of the temperature rise due to infrared rays, one of the two infrared sensor elements and the space temperature sensor element are electrically connected in series. The first series circuit and the second series circuit in which the temperature compensation sensor element and the other of the two infrared detection sensor elements are electrically connected in series are provided, and the first series circuit and the second series circuit are provided. If one end of the series circuit is electrically connected to one output terminal of the DC power supply and the other end of the first series circuit and the second series circuit is electrically connected to the other output terminal of the DC power supply. good. In this configuration, a signal of one polarity corresponding to the temperature rise due to infrared rays is output from the midpoint of the first series circuit, and the other polarity corresponding to the temperature rise due to infrared rays is output from the midpoint of the second series circuit. Signal is output. With this configuration, it is possible to detect the temperature rise due to infrared rays without using load resistance or the like.

In the method for manufacturing an infrared sensor device of the present invention, first, a plurality of solder balls are placed on one of the joining patterns on the first joining pattern of the cap member or on one of the second joining patterns of the substrate with a sensor. Place along. Then, with a predetermined space opened between the cap member and the substrate with the sensor, the cap member and the substrate with the sensor are opposed to each other in the vacuum device. Next, while heating the cap member and the substrate with the sensor, the vacuum device is operated to bring the inside of the spacer into a predetermined degree of vacuum. Next, after the plurality of solder balls are in a molten state, a continuous molten solder layer is formed between the first bonding pattern and the second bonding pattern by the molten solder formed by melting the plurality of solder balls. The cap member and the substrate with the sensor are relatively close to each other. After that, heating is stopped to solidify the continuous molten solder layer. According to the present invention, it is possible to reliably form a continuous molten solder layer between the first bonding pattern and the second bonding pattern by the molten solder formed by melting a plurality of solder balls.

As described above, according to the infrared sensor device according to the present invention, high detection accuracy can be obtained by placing the infrared detection sensor element and the temperature compensation sensor element in the same environment. Further, according to the method for manufacturing an infrared sensor device according to the present invention, it is possible to manufacture an infrared sensor device with high detection accuracy with a high yield.

It is a vertical sectional view which shows the structure of one Embodiment of the infrared sensor device which concerns on this invention, and the dimension such as the thickness of each layer is changed as appropriate for explanation. It is a more detailed end view cut along the line II-II of FIG. 1. (A) is a bottom view showing the lower end surface of the peripheral wall portion of the cap before being joined to the substrate with a sensor in the embodiment of FIG. 1, and (B) is one of the cap members shown in FIG. 3 (A). It is an enlarged cross-sectional view which cut the part along the line BB, and is shown upside down for convenience of explanation. (A), (B), (C), (D), (E), and (F) are vertical cross-sectional views showing the manufacturing process of the infrared sensor device of FIG. 1, respectively. The time course of the temperature and load of the top plate and the temperature of the bottom plate set in each process of the manufacturing process shown in FIG. 4 is shown. It is a vertical sectional view schematically showing the structure of the 2nd Embodiment of the infrared sensor device which concerns on this invention. It is a circuit diagram which shows an example of the circuit for infrared output detection using the infrared sensor device of embodiment of FIG. It is a circuit diagram which shows the other example of the circuit for infrared output detection using the infrared sensor device of embodiment of FIG.

Hereinafter, one embodiment of the infrared sensor device according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a vertical cross-sectional view schematically showing the configuration of the first embodiment of the infrared sensor device according to the present invention, and dimensions such as the thickness of each layer are appropriately changed for the sake of explanation. Further, FIG. 2 is a more detailed end view obtained by cutting the first embodiment of FIG. 1 along the line II-II, and the thickness dimension of each part is exaggerated. As shown in FIG. 1, the infrared sensor device 1 of the present embodiment includes a cap member 10, a substrate 20 with a sensor, and a solder layer 30 for joining the cap member 10 and the substrate 20 with a sensor.

Then, as specifically shown in FIG. 2, the cap member 10 has a peripheral wall portion 12 having an opening 11 on one surface, a facing wall portion 13 facing the opening 11, and a peripheral wall portion 12 surrounding the opening 11. A first bonding pattern 14 [FIG. 3 (A)] formed by forming and patterning a closed loop-shaped solderable metal thin film (gold sputter film in the present embodiment) extending along the lower end surface on the end surface is formed. I have. The facing wall portion 13 is provided with an infrared transmitting portion 15 that transmits infrared rays.

The main body of the cap member 10 is integrally formed by etching a silicon single crystal 18 whose upper end surface and lower end surface are coated with insulating films 16 and 17. As shown in FIG. 2, the infrared transmitting portion 15 is formed to be thinner than the other portions of the facing wall portion 13 so that the infrared rays can pass through the silicon single crystal body 18 of the facing wall portion 13. The insulating film 16 on the infrared transmitting portion 15 is removed. The insulating films 16 and 17 are SiN / SiO ₂ films, and an infrared blocking film 19 made of a thin film layer is formed on the insulating film 16. The insulating films 16 and 17 are SiN / SiO ₂ films, and the infrared blocking film 19 is a NiCr / Au layer formed by sputtering or plating. The first bonding pattern 14 is formed of a Ti / Au (or alloy thereof) thin film formed by sputtering.

The solder layer 30 has a closed loop shape formed along the first joining pattern 14. The solder layer 30 is made of an alloy such as gold tin (AuSn), which is a high melting point solder, and a material having high solder wettability with respect to the solder layer 30 is selected for the first bonding pattern 14.

On the substrate 20 with a sensor formed by etching a silicon substrate, an infrared detection sensor element 21 that receives infrared rays transmitted through the infrared transmitting portion 15 of the cap member 10, and a space temperature sensor that measures the temperature of the internal space. The element 22 and the temperature compensation sensor element 23 are provided. Both the space temperature sensor element 22 and the temperature compensation sensor element 23 are used for temperature compensation of the output of the infrared detection sensor element 21. These sensor elements 21, 22, and 23 are formed by MEMS technology, and a cavity 20A is etched below each sensor element 21, 22, and 23 in order to suppress the thermal influence from the substrate 20. It is formed. The sensor elements 21, 22, and 23 have resistance values, heat capacities, and thermal conductivity that similarly fluctuate with respect to the same temperature, and a bridge circuit in which the sensor elements 21, 22, and 23 are used as resistance elements, respectively (FIG. By forming (not shown), temperature compensation can be applied to the output of the infrared detection sensor element 21.

A second bonding pattern 24, which is a solderable metal thin film layer bonded to the first bonding pattern 14 of the cap member 10, is formed near the peripheral edge of the upper surface of the substrate 20 with a sensor. .. The opening 11 of the cap member 10 is closed by joining the first joining pattern 14 on the lower end surface of the cap member 10 and the second joining pattern 24 on the upper surface of the substrate 20 with a sensor with a solder layer 30. As a result, the internal space surrounded by the cap member 10 and the sensor-equipped substrate 20 becomes airtight to the outside, and when the cap member 10 and the sensor-equipped substrate 20 are joined in a vacuum atmosphere, even under atmospheric pressure. The internal space is kept in a vacuum state. The second bonding pattern 24 is also formed of a Ti / Au thin film.

Two partition walls 31 and 32 are integrally provided on the facing wall portion 13 and the peripheral wall portion of the cap member 10. Each of the partition walls 31 and 32, together with the facing wall portion 13 and the peripheral wall portion 12, constitutes three chambers CH1 to CH3 that divide the internal space of the cap member 10. In FIG. 1, an infrared detection sensor element 21 is housed in a central chamber CH1, a space temperature sensor element 22 is housed in a left chamber CH2, and a temperature compensation sensor element 23 is housed in a right chamber CH3. .. The infrared IR incident from the infrared transmitting portion 15 is blocked by the partition walls 31 and 32, and does not directly hit the space temperature sensor element 22 and the temperature compensation sensor element 23. It should be noted that if the partition walls 31 and 32 are formed at the same time when the inner space is formed by removing the silicon inside the cap member 10 while leaving the outer wall, the man-hours do not need to be increased. The thickness of the partition walls 31 and 32 is set to 10 μm or more so that infrared rays can be blocked. The side surfaces of the partition walls 31 and 32 facing the chamber CH1 may be covered with a metal thin film layer that reflects infrared rays.

In another embodiment, the peripheral wall portion 12 and the facing wall portion 13 of the cap member 10 are integrally molded with a material containing silicon as a main component, for example, single crystal silicon, and at least the cap body. A metal thin film layer such as a solderable Ti / Au thin film that covers the outer surface of the cap body except for the infrared transmitting portion 15 and the inner wall surface is used. In this case, the first bonding pattern can be formed by the metal thin film layer. If such a configuration is adopted, the size can be reduced.

In a state where the cap member 10 and the substrate 20 with a sensor are joined, an infrared ray transmitting portion 15 is incident between the end faces 31A and 32A of the free ends of the partition walls 31 and 32 and the upper surface 20B of the substrate 20 with a sensor. A gap g is formed that blocks the passage of infrared rays but allows the flow of gas. Since the lower end surface 10A of the cap member 10 and the end surfaces 31A and 32A of the free ends of the partition walls 31 and 32 are formed flush with each other, the thickness of the gap g depends on the thickness of the solder layer 30. By doing so, the thickness of the solder layer 30 defines the dimension of the gap g between the end faces 31A and 32A of the free ends of the partition walls 31 and 32 and the upper surface 20B of the substrate 20 with a sensor. The dimension of the gap g in this embodiment = the thickness of the solder layer is 100 μm or less.

The infrared detection sensor element 21, the space temperature sensor element 22, and the temperature compensation sensor element are further reduced in size by being configured as a plurality of MEMS sensor elements laminated on the sensor-equipped substrate 20. That is, each sensor element 21, 22, and 23 are formed on the single crystal silicon layer 25 which is the main body of the substrate 20 with a sensor by using MEMS techniques such as oxidation, diffusion, etching, thin film deposition, photolithography, and plating. It is a MEMS sensor element.

In the actual structure shown in detail in FIG. 2, insulating films 26 and 27, which are SiN / SiO ₂ films, are formed on both sides of the single crystal silicon layer 25. A silicon geoxide (SiO ₂ ) that insulates an electrode layer 28 made of a Ta / Pt thin film, a lead layer 29 made of a Ti / Au / Pt / Au thin film, a thermista film 33 that detects infrared rays, and a thermista film 33 on the insulating film 26. The infrared detection sensor element 21 composed of the insulating film 34 made of) and the surface protective layer 35 made of silicon oxynitride (SiON) has a cavity 20A provided by digging the upper surface of the single crystal silicon layer 25 by etching. It has a microbridge structure bridged between the internal spaces of the cap member 10. As a result, the infrared detection sensor element 21 realizes an ultra-low heat capacity. Since FIG. 2 is an end view, the partition wall 31 is not shown.

The first joining pattern 14 shown in FIG. 3A is formed so as to cover almost the entire lower end surface of the peripheral wall portion 12. When the first joining pattern 14 and the second joining pattern 24 are joined by the solder layer 30, the processing is performed on a very small part, so FIG. 3 (B) is placed on the first joining pattern 14. A plurality of solder balls 37 such as the above are provided. With the solder balls 37 sandwiched between the first bonding pattern 14 and the second bonding pattern 24, the solder balls 37 are heated and melted, and the molten solder material is used as the first bonding pattern 14 and the first bonding pattern 14. A method is adopted in which a closed loop-shaped molten solder layer is formed by flowing it as a whole between the bonding pattern 24 and the soldering pattern 24, and then the solder layer 30 is formed by cooling the molten solder layer. This process will be described in detail later.

On the first joining pattern 14 of FIG. 3A, a total of eight solder balls 37 are arranged in the middle of the corners and sides of the quadrangle. The solder ball 37 is made of a gold-tin alloy, and when the solder ball 37 is melted and cooled between the first joining pattern 14 and the second joining pattern 24, it is sufficiently between the internal space and the outside. The solder balls 37 are properly thick enough to maintain airtightness, and the gap g between the free ends of the partition walls 31 and 32 and the substrate 20 with a sensor is sufficiently large to allow gas to flow. The size and number of mounts are selected.

In order to reduce the size and cost of the device, it is preferable to make the thickness of the solder layer 30 and the width of each bonding pattern as small as possible. However, the size of the joint portion of the solder ball 37 is technically limited, and as shown in FIG. 3B, it is preferably 140 μm, which is substantially equal to the width W1 of the first joint pattern 14.

Next, the manufacturing process of the embodiment of FIG. 1 will be described with reference to FIGS. 4 and 5. Prior to joining the cap member 10 and the sensor-equipped substrate 20, a plurality of solder balls 37 are placed on the first joining pattern 14 of the cap member 10 (in other embodiments, on the second joining pattern of the sensor-equipped substrate). Is arranged along the first joining pattern 14.

First, as shown in FIG. 4A, the cap member 10 and the sensor-equipped substrate 20 face each other in the vacuum device with a predetermined space opened between the cap member 10 and the sensor-equipped substrate 20. A predetermined space is secured by a spacer S sandwiched between the lower end of the solder ball 37 of the cap member 10 and the upper surface of the second joining pattern 24 of the substrate 20 with a sensor. Above the cap member 10, top plate TPs are arranged at intervals of several cm. The substrate 20 with a sensor is placed on the bottom plate BP.

The temperature of the top plate TP can be raised from room temperature to the temperature at which the solder balls 37 melt, and the top plate TP can be moved downward to apply a load. The temperature of the bottom plate BP can also be raised, and it can be cooled to room temperature by flowing air below the bottom plate BP to dissipate heat.

In the state of FIG. 4A, both the top plate TP and the bottom plate BP are at room temperature, and there is a gap between the top plate TP and the cap member 10, and no load is applied. The state at this time is the period (A) in FIG.

Next, the temperature rise of the top plate TP and the bottom plate BP is started, and while heating the cap member 10 and the substrate 20 with the sensor, the vacuum device is operated to bring the space formed by the spacer into a predetermined degree of vacuum. (Sections of FIG. 4 (B) and FIG. 5 (B)).

When the temperatures of the top plate TP and the bottom plate BP reach near the melting temperature of the solder balls 37 (about 250 ° C.), preheating is performed for about 20 minutes (sections 4 (C) and 5 (C) in FIG. 5). Subsequently, when the temperature of both plates is further raised to 320 ° C. (sections (D) in FIGS. 4 (D) and (D) in FIG. 5), the solder balls 37 begin to melt. After a part of the solder balls 37 is in a molten state, the spacer is pulled out, the top plate TP is lowered, and pressure is applied until a predetermined load (2000 N) is reached, and then the pressure is maintained (FIG. 4 (E)). , Section (E) in FIG. 5).

As a result, the cap member 10 and the substrate 20 with a sensor are relatively close to each other, and the molten solder formed by melting each solder ball 37 causes continuous molten solder between the first bonding pattern 14 and the second bonding pattern 24. Form a layer. After that, the heating of the top plate TP and the bottom plate BP is stopped, the top plate TP is naturally cooled, and the bottom plate BP is air-cooled to cool and solidify the continuous molten solder layer to form the solder layer 30 (the solder layer 30 is formed. Sections 4 (F) and 5 (F). After that, when both plates reach a predetermined temperature (near normal temperature), the pressurization by the top plate TP is released and the inside of the vacuum device is opened to the atmosphere.

According to the manufacturing method of the present embodiment, a continuous molten solder layer is surely formed between the first bonding pattern 14 and the second bonding pattern 24 by the molten solder formed by melting a plurality of solder balls 37. can do.

Next, the operation of this embodiment will be described.

According to the present embodiment, by providing the partition walls 31 and 32 in the internal space of the cap member 10, the infrared IR transmitted through the infrared transmitting portion 15 is directly applied to the space temperature sensor element 22 and the temperature compensation sensor element 23. You can prevent it from hitting. A gap g is formed between the lower ends of the upper partition walls 31 and 32 and the upper surface of the substrate 20 with a sensor to block the passage of incident infrared IR but allow the flow of gas. Adjacent chambers partitioned by partition walls 31, 32 can be maintained at the same degree of vacuum.

Therefore, except for the condition that the infrared IR hits, the infrared detection sensor element 21 that receives the infrared IR transmitted through the infrared transmission unit 15, the space temperature sensor element 22 used for temperature compensation of the output of the infrared detection sensor element, and the temperature compensation sensor. The element 23 can be placed in the same environment. As a result, temperature compensation using the space temperature sensor element 22 and the temperature compensation sensor element 23 can be realized with high accuracy, and an infrared sensor device with high detection accuracy can be provided.

(Modification example)
In the above embodiment, the partition walls 31 and 32 are each composed of one wall portion. In this case, increasing the thickness increases the infrared blocking ability. However, it goes without saying that the partition walls 31 and 32 may have a double structure composed of two wall portions arranged side by side at intervals.

Further, in order to enhance the blocking effect, it is preferable to make the wall thickness of the cap member and the partition wall as thick as possible.

[Second Embodiment]
FIG. 6 is a vertical cross-sectional view schematically showing the configuration of the second embodiment of the infrared sensor device according to the present invention, and dimensions such as the thickness of each layer are appropriately changed for the sake of explanation. In FIG. 6, the same parts as those in the first embodiment of FIG. 1 are designated by reference numerals obtained by adding the number of 100 to the number of reference numerals in FIG. 1, and the description thereof will be omitted.

In the present embodiment, the internal space of the cap member 10 is divided into the first chamber CH1 and the second chamber CH2 by a single partition wall 131. Also in this embodiment, in the state where the cap member 110 and the substrate 120 with the sensor are joined, the infrared transmissive portion 115 is between the end surface 131A of the free end portion of the partition wall 131 and the upper surface 20B of the substrate 20 with the sensor. A gap g is formed that blocks the passage of infrared rays incident from the source but allows the flow of gas. The thickness of the gap g depends on the thickness of the solder layer 130. The dimension of the gap g in this embodiment = the thickness of the solder layer is 100 μm or less.

Further, on the substrate 120 with a sensor formed by etching a silicon substrate, the infrared detection sensor elements 121A and 121B that receive infrared rays transmitted through the infrared transmitting portion 115 of the cap member 110, and the temperature of the internal space are measured. The space temperature sensor element 122 and the temperature compensation sensor element 123 are provided. Both the space temperature sensor element 122 and the temperature compensation sensor element 123 are used for temperature compensation of the outputs of the infrared detection sensor elements 121A and 121B. These sensor elements 121A and 121B, 122 and 123 are also formed by MEMS technology, and in order to suppress the thermal influence from the substrate 120 below the sensor elements 121A and 121B and the sensor elements 122 and 123, The cavity 120A is formed by etching. Each of the sensor elements 121A and 121B, 122 and 123 has a similarly variable resistance value, heat capacity and thermal conductivity with respect to the same temperature.

In the present embodiment, the first chamber CH1 accommodates two infrared detection sensor elements 121A and 121B, and the second chamber CH2 accommodates the space temperature sensor element 122 and the temperature compensation sensor element 123. ing. The infrared rays incident from the infrared transmitting portion 115 are blocked by the partition wall 131, and do not directly hit the space temperature sensor element 122 and the temperature compensation sensor element 123. The thickness of the partition wall 131 is set to 10 μm or more so that infrared rays can be blocked.

By doing so, the area of the infrared transmitting portion 115 provided for the first chamber CH1 can be increased, and the light receiving surfaces of the two infrared detection sensor elements 121A and 121B can be increased. Further, when the same number of sensor elements are arranged in the first chamber CH1 and the second chamber CH2 as in the present embodiment, the temperature changes in the first and second chambers are substantially the same. Can be done.

FIG. 7 shows an example of a circuit of an infrared sensor device unit using the infrared sensor device 101 of the embodiment of FIG. In FIG. 7, the portion surrounded by the frame is the circuit portion of the infrared sensor device 1. Each sensor element 121A and 121B, 122 and 123 is an infrared detection element (bolometer) having substantially the same resistance value (Rs = Rd = Rr = Rref), the same heat capacity, and the same thermal conductivity, which fluctuate in the same manner with respect to the same temperature. ). In FIG. 7, the RLs are the first and second load resistors RL1 and RL2 created outside the sensor, and the ones having the same resistance value are used.

This infrared sensor device unit includes a first series circuit in which an infrared detection sensor element 121A and an air temperature sensor element 122 are electrically connected in series, an infrared detection sensor element 121B, and a first load resistance RL1. It includes a second series circuit electrically connected, and a third series circuit in which the temperature compensation sensor element 123 and the second load resistor RL2 are electrically connected in series. One end of the first series circuit to the third series circuit is electrically connected to the positive output terminal of the DC power supply DC, and the other end of the first series circuit to the third series circuit is the negative output terminal of the DC power supply. Is electrically connected to. Then, a signal corresponding to the temperature rise due to infrared rays is output from the connection point (middle point) of the infrared detection sensor element 121A and the space temperature sensor element 122 of the first series circuit. Further, a signal corresponding to the environmental temperature is output from the connection point (midpoint) of the temperature compensation sensor element 123 of the third series circuit and the second load resistance RL2. According to this infrared sensor device unit, it is possible to detect the temperature rise due to infrared rays and the environmental temperature with high accuracy.

The following conditions can be considered as factors that change the resistance value of the sensor element.

T1 ・ ・ ・ Temperature change due to receiving infrared rays T2 ・ ・ ・ Temperature change due to heat generated by current flowing through the bolometer T3 ・ ・ ・ Temperature change due to change in ambient temperature Only the first chamber CH1 is T1 It is possible to capture the temperature change, and the temperature change of T3 acts uniformly on all the sensor elements. Considering the influence of T2, the temperature of Ta rises in the infrared detection sensor element 121A and the space temperature sensor element 122 due to the current Ia. The temperature of Tb rises in the sensor element 121B due to the current Ib. In the temperature compensation sensor element 123, the temperature of Tc rises due to the current Ic. Here, the sum of the temperature rises due to the currents of the first chamber CH1 and the second chamber CH2 is the sum of the temperature rises of the first chamber T2 = Ta + Tb, respectively.
Sum of temperature rises in the second chamber T2 = Ta + Tc
Will be. Here, the current Ib and the current Ic can be considered to be substantially the same as the current Ib and the current Ic because the sensor element 121B and the temperature compensation sensor element 123 have the same characteristics. It can be said that the temperature changes Tb and Tc are almost the same.

By forming the circuit in this way, the temperature rise due to the current can be made substantially the same in the first chamber CH1 and the second chamber CH2. Actually, the total temperature rise T2 of the first chamber CH1 and the total temperature rise T2 of the second chamber CH2 are completely complete due to the small variation of each sensor element and the influence of infrared rays on the infrared detection sensor element 121B. However, in this circuit, the difference between the T2s of the first chamber CH1 and the second chamber CH2 can be made as small as possible. As a result, the infrared detection sensor element 121A and the space temperature sensor element 122 are arranged in series and the midpoint output thereof is read, so that the output (IR output) corresponding to the temperature rise due to infrared rays, that is, the temperature change T1 by receiving infrared rays. It becomes possible to capture only. Further, in this circuit, the midpoint output of the temperature compensation sensor element 123 and the load resistance RL is the environmental temperature output.

FIG. 8 shows another example of a circuit of an infrared sensor device unit using the infrared sensor device 101 of the embodiment of FIG. In FIG. 8, the portion surrounded by the frame is the circuit portion of the infrared sensor device 1. In this circuit, the first series circuit in which the infrared detection sensor element 121A and the space temperature sensor element 122 are electrically connected in series, and the infrared detection sensor element 121B of the temperature compensation sensor element 123 are electrically connected. It includes a second series circuit connected in series. One end of the first series circuit and the second series circuit is electrically connected to the positive output terminal of the DC power supply DC, and the other end of the first series circuit and the second series circuit is connected to the negative output terminal of the DC power supply. It is electrically connected. In this configuration, a signal of one polarity (+) corresponding to the temperature rise due to infrared rays is output from the connection point (middle point) of the infrared detection sensor element 121A and the space temperature sensor element 122 of the first series circuit. A signal of the other polarity (-) corresponding to the temperature rise due to infrared rays is output from the connection point (middle point) of the infrared detection sensor element 121B with the temperature compensation sensor element 123 of the second series circuit. By reading the difference between the respective midpoint outputs, that is, the difference between the IR output + and the IR output-, the temperature change T1 due to infrared rays can be extracted more efficiently. Regarding the influence of the temperature change amount T2 due to the current, since the current of Ia flows through each element, the total temperature rise T2 of the first chamber and the total temperature rise T2 of the second chamber are almost equal. The total temperature rise of the first chamber T2 = the total temperature rise of the second chamber T2 = Ta.

The method of using the infrared sensor device of this embodiment is not limited to using the above circuit.

1,101 Infrared sensor device 10,110 Cap member 11,111 Opening 12,112 Peripheral wall 13,113 Facing wall 14 First joining pattern 15,115 Infrared transmission 20,120 Substrate with sensor 21,121 Infrared detection Sensor element 22,122 Spatial temperature sensor element 23,123 Temperature compensation sensor element 24 Second bonding pattern 30,130 Solder layer 31, C32,131 Partition wall IR infrared

Claims (12)

A closed loop-shaped solderable first joint pattern extending along the end face of the peripheral wall portion having an opening on one surface, the facing wall portion facing the opening, and the end surface of the peripheral wall portion surrounding the opening. And a cap member provided with an infrared transmitting portion that transmits infrared rays on the facing wall portion.
A closed loop-shaped solder layer formed along the first joining pattern,
The solder layer comprises one or more infrared detection sensor elements that receive infrared rays transmitted through the infrared transmitting portion, one or more temperature compensation sensor elements used for temperature compensation of the output of the one or more infrared detection sensor elements, and the solder layer. A substrate with a sensor for closing the opening is provided with a second solderable bonding pattern to be bonded to the bonding pattern of 1.
An infrared sensor device in which an internal space surrounded by the cap member and the substrate with a sensor is held in a vacuum state.
One or more partitioning the internal space of the facing wall portion and the peripheral wall portion of the cap member so as to prevent the infrared rays incident from the infrared transmitting portion from directly hitting the one or more temperature compensating sensor elements. The partition wall is provided integrally,
A gap is formed between the one or more partition walls and the substrate, which blocks the passage of the infrared rays incident from the infrared ray transmitting portion but allows the flow of gas.
The end face of the cap member and the end face of the free end of the partition wall are flush with each other.
An infrared sensor device characterized in that the thickness of the gap depends on the thickness of the solder layer . The infrared sensor device according to claim 1, wherein the one or more temperature compensation sensor elements are an internal space temperature sensor and a reference temperature sensor that measure the temperature of the internal space. The peripheral wall portion and the facing wall portion of the cap member are the cap body formed of a material containing silicon as a main component and integrally molded, and the cap body except for at least the infrared ray transmitting portion and the inner wall surface of the cap body. Consists of a solderable metal thin film layer that covers the outer surface of the body,
The infrared sensor device according to claim 1, wherein the first bonding pattern is formed by the metal thin film layer. The substrate with a sensor includes a support substrate mainly composed of silicon, and a plurality of MEMS sensor elements laminated on the support substrate in order to form the infrared detection sensor element and one or more temperature compensation sensor elements, respectively. Equipped with
The infrared sensor device according to claim 1 or 3 , wherein the second bonding pattern is formed of a solderable metal thin film layer. The infrared sensor device according to claim 1, wherein the thickness of the solder layer is 100 μm or less. The infrared sensor device according to claim 1, wherein the partition wall has a thickness of 10 μm or more. The one or more partition walls are composed of two partition walls lined up at intervals.
The infrared detection sensor element is housed in a first chamber formed between the two partition walls, and is between the partition wall and the peripheral wall portion of one of the two partition walls. The internal space temperature sensor is housed in the formed second chamber, and in the third chamber formed between the other partition wall and the peripheral wall portion of the two partition walls. Is the infrared sensor device according to claim 4 , wherein the reference temperature sensor is housed. The one or more partition walls are one partition wall.
Two infrared detection sensor elements are housed in a first chamber formed between the one partition wall and the peripheral wall portion, and between the single partition wall and the peripheral wall portion. The space temperature sensor element and the temperature compensation sensor element are housed in the second chamber formed in the above.
The infrared sensor device according to claim 2 , wherein the two infrared detection sensor elements, the space temperature sensor element, and the temperature compensation sensor element are infrared detection elements having the same electrical resistance characteristics depending on the temperature. An infrared sensor device unit comprising the infrared sensor device according to claim 8 and generating an output corresponding to a temperature rise due to infrared rays.
A first series circuit in which one of the two infrared detection sensor elements and the space temperature sensor element are electrically connected in series,
A second series circuit in which the other of the two infrared detection sensor elements and the first load resistance are electrically connected,
A third series circuit in which the temperature compensation sensor element and the second load resistance are electrically connected in series is provided.
One end of the first series circuit to the third series circuit is electrically connected to one output terminal of the DC power supply.
The other end of the first series circuit to the third series circuit is electrically connected to the other output terminal of the DC power supply.
A signal corresponding to the temperature rise due to the infrared rays is output from the midpoint of the first series circuit.
An infrared sensor device unit characterized in that a signal corresponding to an environmental temperature is output from the midpoint of the third series circuit. The infrared sensor device unit according to claim 9 , wherein the first load resistance and the second load resistance have the same resistance value. An infrared sensor device unit comprising the infrared sensor device according to claim 8 and generating an output corresponding to a temperature rise due to infrared rays and an output of an environmental temperature.
A first series circuit in which one of the two infrared detection sensor elements and the space temperature sensor element are electrically connected in series,
A second series circuit in which the temperature compensation sensor element and the other of the two infrared detection sensor elements are electrically connected in series is provided.
One end of the first series circuit and the second series circuit is electrically connected to one output terminal of the DC power supply.
The other ends of the first series circuit and the second series circuit are electrically connected to the other output terminal of the DC power supply.
A signal of one polarity corresponding to the temperature rise due to the infrared rays is output from the midpoint of the first series circuit.
An infrared sensor device unit characterized in that a signal having the other polarity corresponding to the temperature rise due to the infrared ray is output from the midpoint of the second series circuit. The method for manufacturing an infrared sensor device according to claim 1.
A plurality of solder balls are arranged along the one joining pattern on the first joining pattern of the cap member or on one joining pattern of the second joining pattern of the substrate with a sensor.
With a predetermined space opened between the cap member and the substrate with the sensor, the cap member and the substrate with the sensor are opposed to each other in the vacuum device.
While heating the cap member and the substrate with the sensor, the vacuum device is operated to bring the space into a predetermined degree of vacuum.
After the plurality of solder balls are in a molten state, a continuous molten solder layer is formed between the first bonding pattern and the second bonding pattern by the molten solder formed by melting the plurality of solder balls. The cap member and the substrate with the sensor are relatively close to each other so as to be used.
A method for manufacturing an infrared sensor device, which comprises then stopping the heating to solidify the continuous molten solder layer.

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