JP2001174324A - Infrared ray detector and infrared ray detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an infrared ray detector, to reduce a cost and to improve the productivity. SOLUTION: This infrared ray detector is provided with a first substrate section 10 and a second substrate section 20 connected and arranged face to face. The first substrate section 10 is provided with an infrared ray transmitting substrate 11 formed with a cavity section 12 opened on one face facing the second substrate section 20, an infrared ray detecting element 14 arranged on the cavity section 12 on one face side of the substrate 11, and protruded electrodes 16 formed on one face of the substrate 11 to extract the output signal of the infrared ray detecting element 14 to the outside. The second substrate section 20 is provided with an insulating substrate 21 formed with a cavity section 22 at the portion facing the infrared ray detecting element 14 and formed with connecting holes 23 penetrating at the portions facing the protruded electrodes 16, conductive sections 24 made of a conductive material buried in the connecting holes 23 and electrically connected to the protruded electrodes 16, and a surface electrode 25 electrically connected to the conductive sections 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal infrared detector and an infrared detector including the infrared detector.

[0002]

2. Description of the Related Art An infrared detector for detecting infrared rays includes a thermal infrared detector which indirectly detects infrared rays by converting infrared rays into heat and detecting the heat, and an infrared ray which is an electromagnetic wave directly. There is a semiconductor infrared detector that detects using a quantum effect. Thermal infrared detectors are widely used as low-cost infrared detectors because they do not require cooling as compared with semiconductor infrared detectors. As a thermal infrared detector, a pyroelectric sensor, a thermopile, a temperature-sensitive bolometer, and the like are known.

In recent years, attempts have been made to reduce the size and sensitivity of these thermal infrared detectors using so-called micromachining technology. That is, by using micromachining technology, a minute infrared detecting element portion on a substrate is configured to have a small heat capacity and a large thermal resistance, and to increase the temperature change of the infrared detecting element portion due to an infrared ray to be detected. As a result, the sensitivity and size of the infrared detector are increased.

For example, JP-A-6-241889 and JP-A-6-74820 disclose that the above-mentioned infrared detecting element is realized by a so-called micro air bridge structure using a micromachining technique. An example in which the detector is packaged so as to be used as an electronic component is disclosed.

[0005]

However, the conventional infrared detector as described above has a problem that the packaging portion becomes complicated and it is difficult to reduce the size and the cost in practical use as a device. was there.

[0006] For example, Japanese Patent Application Laid-Open No. 6-241889 discloses an infrared detector in which an infrared detecting element having a micro air bridge structure is packaged in a metal case comprising a metal stem and a metal cap to which an infrared filter is adhered. Is disclosed. However, packaging using such a metal case has problems that the cost of the metal case itself is high and that production takes time. Even if the infrared detector is downsized using micromachining technology, the metal case itself is the same as an infrared detector using a conventional bulk element. There is a problem that does not become.

Further, with the progress of surface mounting technology for electronic circuit components, with the trend toward surface mounting of electronic components and sensors (chip components), infrared detecting elements are packaged in metal cases and leaded. In the case of an infrared detector connected to an external circuit by a wire, it is necessary to take a separate process from other electronic components in a process of mounting on a circuit board, which causes an increase in cost.

Further, Japanese Patent Application Laid-Open No. 6-74820 discloses that
Similarly, using micromachining technology, an infrared detection element with a micro air bridge structure is provided on a cavity penetrating the substrate, lids are hermetically sealed on both sides of such a substrate, and these are further mounted on a copper pedestal. There is disclosed an infrared detector configured to be fitted in the infrared detector.

[0009] The infrared detector described above can be downsized compared to an infrared detector packaged using a metal case. However, the structure of this infrared detector is extremely complicated because it is necessary to extract the output of the infrared detection element via a flexible printed circuit board.
There is a problem that productivity is low and cost is high.

[0010] As described above, the conventional infrared detector has a problem in packaging, particularly in forming an output signal extraction electrode.
It has been difficult to reduce the size, ease of manufacture, and cost reduction.

[0011] For example, see IEEJ Transactions, Vol.
E, No. 9 (1998), pp. 393-400, describes a surface-mount bolometer-type infrared detector using a Schottky barrier diode as an infrared detection element and a packaged silicon substrate itself (hereinafter referred to as the 1 of the prior art).

Further, Japanese Patent Application Laid-Open Nos. Hei 6-74820 and Hei 6-213724 disclose a so-called micro structure in which a silicon substrate itself is packaged and a signal is taken out using a flexible printed circuit board. An air-bridge type infrared detector (hereinafter referred to as a second conventional infrared detector) is disclosed.

As described above, by using the micromachining technology, the infrared detector conventionally sealed in a metal case such as TO-5 can be surface-mounted using the substrate itself on which the infrared detecting element is formed as a package. It can be realized as a small sensor.

Meanwhile, the thermal infrared detector detects a difference between infrared light incident on the detector and infrared light emitted by the detector itself as a temperature change of the detecting section and outputs it. Therefore,
The thermal infrared detector outputs a false signal when the temperature inside the infrared detector changes due to a sudden change in the ambient atmosphere temperature, particularly when a transient temperature distribution occurs inside the detector. For this reason, in order to accurately measure the amount of incident infrared light in a thermal infrared detector, the temperature of the infrared detector itself must be stabilized against sudden changes in ambient temperature, and the temperature of the infrared detector itself must be different. Need to be detected by the method.

For this reason, conventionally, in order to increase the heat capacity and stabilize the temperature of the infrared detector itself against sudden changes in the ambient temperature, the infrared detector itself is fitted into a copper metal holder, and the infrared detector itself is mounted. In order to detect the temperature of the infrared detector, a temperature sensor such as a thermistor is arranged close to the infrared detector so as to be thermally sufficiently coupled to the infrared detector to constitute an infrared detector.

However, the infrared detecting device thus configured has a complicated structure, a large volume, and poor thermal coupling between the temperature sensor and the infrared detector. There was a problem that cost reduction was difficult.

For example, a first conventional infrared detector is:
Since the infrared detector itself is a surface mount type package,
It can be directly mounted on a printed wiring board. However, since the infrared detector main body is extremely small and has a small heat capacity, when the ambient temperature changes suddenly, the temperature change of the infrared detector main body becomes sharp, and the infrared detector may generate an erroneous signal. .

In the first conventional infrared detector,
Although the main body of the infrared detector is made of a single crystal silicon substrate, silicon has low mechanical strength since it has cleavage and lacks mechanical strength. For this reason, such an infrared detector may cause chipping during handling when mounted on a printed wiring board, and may be damaged if the printed wiring board is significantly deformed such as warpage.

When the infrared detector of the first conventional example is used, a temperature sensor for detecting the temperature of the infrared detector main body needs to be arranged on the printed wiring board in the same manner as the infrared detector. is there. However, since the printed wiring board usually has a very low thermal conductivity, it cannot be expected that the infrared detector and the temperature sensor are thermally connected well. Therefore, when an infrared detector and a temperature sensor are placed on a printed wiring board, a difference occurs between the true temperature of the infrared detector body and the temperature measured by the temperature sensor when the ambient temperature changes, resulting in an error in infrared detection. Would.

In the first conventional infrared detector,
The following method is used as a method of forming a silicon substrate itself into a surface mount package. In other words, in this method, a hole having a V-shaped cross section penetrating through the front surface of the silicon substrate from the back surface of the silicon substrate on which the infrared detecting element is to be formed by using an anisotropic etching method. A silicon insulating film is formed, and a metal film is formed from the back surface of the substrate by a sputtering method. Next, the oxide film in the through portion of the substrate is removed by a dry etching method,
A metal film is formed on that part from the front side of the substrate, and finally,
The conductor is buried in a V-shaped hole by dipping in a solder bath. Thus, in the first conventional infrared detector,
The cost is high because the silicon substrate itself is a surface-mounted package in a very expensive and costly manner.

On the other hand, in the second conventional infrared detector,
A metal holder is used to increase the heat capacity of the infrared detector. However, for this reason, it is necessary to provide a wiring portion for extracting the signal of the infrared detector to the outside using a flexible printed circuit board and separately from the infrared detector. Since the cost of a metal processed part such as a metal holder or a flexible printed circuit board is extremely high, it is difficult to reduce the cost of the second conventional infrared detector.

In the method of using a flexible printed circuit board to form a wiring section for extracting signals from an infrared detector to the outside, the process of attaching the flexible printed circuit board to a small infrared detector requires a lot of time and costs. Easy to get high. In addition, this method lacks reliability because it is difficult to increase the mounting strength of the flexible printed circuit board with respect to the infrared detector. In addition, since attention must be paid to the electrical insulation between the wiring portion and the metal holder, assembly takes time.

Further, in order to measure the intensity of incident infrared rays using the infrared detector of the second conventional example, it is necessary to measure the temperature of the infrared detector itself. for that purpose,
It is necessary to separately provide a temperature sensor such as a thermistor near the infrared detector. This temperature sensor must be in contact with the metal holder in a thermally tight and electrically insulated state. However, such a configuration
It is not practical because the number of assembling steps and wiring work increases.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide an infrared detector capable of reducing the size, reducing the cost, and improving the productivity.

A second object of the present invention is to provide an infrared detector capable of miniaturization, cost reduction and high accuracy.

[0026]

SUMMARY OF THE INVENTION An infrared detector according to the present invention includes a first substrate portion and a second substrate portion which are arranged and joined to face each other, and wherein the first substrate portion is provided with a first substrate portion. A first substrate in which a cavity opening on one surface facing the second substrate is formed; an infrared detecting element disposed on the cavity on one surface of the first substrate; A protruding electrode formed on one surface of the substrate for taking out an output signal of the infrared detection element to the outside; and the second substrate portion has a cavity formed in a portion facing the infrared detection element. A connecting hole penetrating at a portion facing the protruding electrode, an insulating second substrate arranged and joined to face the first substrate, and a conductive hole embedded in the connecting hole. It is made of a substance and has a conductive portion electrically connected to the protruding electrode. It is intended.

In the infrared detector according to the present invention, the infrared light to be detected enters from the first substrate side and enters the infrared detecting element through the cavity of the first substrate. The output signal of the infrared detecting element is taken out to the outside via the protruding electrode and the conductive part.

In the infrared detector according to the present invention, the first substrate has an infrared transmitting property, and the hollow portion of the first substrate has the first substrate.
May be opened only on one side without penetrating through the substrate. In this case, the first substrate may be made of single crystal silicon having a (100) plane orientation, and the cavity of the first substrate may be formed by anisotropic etching.

Further, in the infrared detector according to the present invention, the cavity of the first substrate penetrates the first substrate, and the infrared detector is further provided on the opposite side of the first substrate from the second substrate. And a third substrate having an infrared-transmitting property, which is disposed and bonded to the third substrate.

The infrared detecting apparatus of the present invention comprises an insulating substrate having a high thermal conductivity, a surface-mounted infrared detector mounted on the substrate, and a temperature sensor mounted on the substrate and detecting the temperature of the substrate. A sensor element, and an electrode formed on the substrate, for taking out the output signal of the infrared detector and the temperature sensor element to the outside, wherein the surface-mounted infrared detector is the above-described infrared detector of the present invention. is there.

In the infrared detecting device of the present invention, the infrared detector and the temperature sensor element are thermally and tightly coupled via the insulating substrate having high thermal conductivity.

[0032] The infrared detector of the present invention may further include a circuit element mounted on a substrate.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. [First Embodiment] FIG. 1 is a sectional view showing a configuration of an infrared detector according to a first embodiment of the present invention. The infrared detector according to the present embodiment includes a first substrate unit 10 and a second substrate unit 20.
And These board parts 10 and 20 are arranged so that the first board part 10 is on the upper side, and are joined to each other.

The first substrate unit 10 is a substrate 1 that transmits infrared light.
One. The substrate 11 is provided with a non-penetrating hollow portion 12 that is open only on one surface side facing the second substrate portion 20 from the front surface (the lower surface in FIG. 1) to the rear surface (the upper surface in FIG. 1). ing. On the cavity 12 on the lower surface side of the substrate 11, an infrared detecting element 14 supported by a support 13 having a bridge structure provided on the lower surface side of the substrate 11 is provided. Further, on the lower surface side of the substrate 11, an electrode portion 15 connected to the infrared detecting element 14 and a plurality of protruding electrodes 16 connected to the electrode portion 15 and protruding downward are provided. Note that an infrared antireflection film 17 may be provided on the upper surface of the substrate 11.

The second substrate section 20 has an insulating substrate 21. The substrate 21 includes a first substrate 10 at a portion facing the infrared detecting element 14 and the cavity 12 of the first substrate 10.
And a non-penetrating hollow part 22 which is opened only on the substrate part 10 side. The substrate 21 includes the first substrate 1
In a portion facing the protruding electrode 16 of the
Is formed.

A conductive portion 24 is formed in the connection hole 23 by filling a conductive material. This conductive part 24
It is electrically connected to the protruding electrode 16. On the lower surface of the insulating substrate 21, a surface electrode 25 electrically connected to the conductive portion 24 is provided. The surface electrode 25 is used as an output terminal for extracting an output signal of the infrared detection element 14 to the outside, and has an appropriate shape.

The first substrate unit 10 and the second substrate unit 20
Via the bonding layer 19, the cavities 12, 22 and the connection holes 23
It is joined at other parts. Thereby, the cavity 1
2 and 22 are hermetically sealed with respect to the surrounding atmosphere.

In the infrared detector configured as described above, the infrared light to be detected is emitted from the back surface of the substrate 11 (FIG. 1).
In this case, the light enters from the upper side) and enters the infrared detecting element 14 through the cavity 12. Therefore, the substrate 11 may be any material as long as it has infrared transmittance as described above and the cavity 12 can be formed by etching from the surface of the substrate 11. As a material of such a substrate 11, single crystal silicon (Si), polycrystalline silicon, single crystal germanium (Ge), polycrystalline germanium, infrared transmitting glass, or the like can be used.

In particular, when a single crystal silicon substrate having a (100) plane orientation is used as the substrate 11 and the cavity 12 is formed by anisotropic etching, as shown in FIG.
2 has a trapezoidal pyramid shape, and a plane parallel to the back surface (the top surface in FIG. 1) of the substrate 11 can be formed as the bottom surface of the cavity 12. Thereby, the infrared ray incident from the back surface of the substrate 11 is not scattered but linearly
4, the infrared rays applied to the infrared detector can be made incident on the infrared detecting element 14 without loss.

When the infrared anti-reflection film 17 is provided on the back surface of the substrate 11, the reflection loss of the infrared light on the back surface of the substrate 11 can be reduced, and the sensitivity of the infrared detector to the infrared light can be increased. In addition, the infrared anti-reflection film 17
Instead, an infrared filter film that selectively transmits infrared light of a specific wavelength may be provided. Infrared anti-reflective coating 17
Known materials such as a ZnS single-layer film having an optical thickness of １ ／ of the infrared wavelength to be detected and a multilayer film in which ZnS and Ge are periodically laminated can be used. Also,
As the infrared filter film, for example, a multilayer film in which ZnS and Ge are periodically laminated can be used.

The infrared detecting element 14 is disclosed in
Various known infrared detecting elements such as a bolometer using a thin film thermistor as disclosed in Japanese Patent No. 318420 and a thermopile including a plurality of thin film thermocouples connected in series as described in Japanese Utility Model Application Laid-Open No. 7-33433 are used. be able to.

As the substrate 21, it is desirable to use a glass or ceramic substrate whose thermal expansion coefficient is similar to that of the substrate 11. For example, when a silicon substrate is used as the substrate 11, a Pyrex glass substrate can be used as the substrate 21.

As a method of forming the hollow portion 22 and the connection hole 23 provided in the substrate 21, a method of processing cultivated land such as ultrasonic processing, drill processing, etching method, sand blast method, and laser processing method may be used. it can.

As described above, the first substrate unit 10 (the substrate 1
1) and the second substrate portion 20 (substrate 21) are joined by the joining layer 19, and the cavity portion 1 surrounding the infrared detecting element 14
2 and 22 are kept airtight. The first substrate unit 10 and the second
A known method such as anodic bonding, low-melting glass bonding, or resin bonding can be used as the bonding method with the substrate portion 20.

In particular, when the cavities 12 and 22 are kept in a vacuum, it is desirable to use an anodic bonding method having high airtightness and high reliability. When the anodic bonding method is used, the insulating substrate 21 itself is made of alkali glass, or an alkali glass thin film is formed on the bonding surface of the substrate 21 with the substrate 11, and the substrate 11 is made of a silicon substrate. It is necessary to expose the silicon at the bonding surface with the substrate 21 or to form a silicon thin film on the bonding surface of the substrate 11.

In the case of filling an inert gas or a gas having a low thermal conductivity such as Xr or Kr in the cavities 12 and 22, a method such as low melting point glass bonding or resin bonding may be used. . In the case of using resin bonding, if a sheet-shaped adhesive obtained by pressing or excimer laser processing an epoxy-based adhesive in advance into the shape of the bonding surface is used for the bonding layer 19, bonding is easy and low cost. .

In the case of low melting point glass bonding, for example, a low melting point glass paste is formed on the upper surface of the substrate 21 by a printing method, this is used as a bonding layer 19, and after calcining, the substrates 11, 21 are formed.
The substrates 11 and 21 can be joined by pressing and heating the substrates. Alternatively, the low melting point glass film may be formed by a sputtering method to form the bonding layer 19, and the substrates 11 and 21 may be bonded by pressing and heating the substrates 11 and 21. In the case of low-melting glass bonding, depending on the heat resistance of the material used for the infrared detecting element 14, the electrode portion 15, and the protruding electrode 16 in the substrate portion 11, a glass having a low melting point should be used to prevent the deterioration. It is desirable to use.
For example, the heat resistance of aluminum that can be used as the material of the electrode unit 15 in the substrate unit 11 is up to about 450 ° C, and the heat resistance of gold is up to about 650 ° C. Therefore, as a low melting point glass, the softening point is 650 to 600 °.
C or less, desirably 450 ° C or less is preferably used. As such a low-melting glass, for example, a glass having a softening point of 450 ° C. or less and B ₂ O ₃ .PbO
System composite glass or the like can be used. Further, as a low melting point glass having a softening point of 650 to 600 ° C or less, Pb
_{O · B 2 O 3 · SiO} 2 -based _{glass, PbO · B 2 O 3 ·} Si
O ₂ · Al ₂ O ₃ glass, ZnO · B ₂ O ₃ · SiO ₂ glass, ZnO · B ₂ O ₃ · SiO ₂ · Al ₂ O ₃ glass, or the like can be used.

By the way, in the infrared detector according to the present embodiment, the output signal of the infrared
5, protruding electrode 16, conductive material 24 and surface electrode 2
5 to the outside.

Here, if there is no protruding electrode 16 as shown in FIG. 2, even if a conductive material is filled in the connection hole 23 provided in the substrate 21 to form the conductive portion 24, In some cases, conduction between the electrode portion 15 and the conductive portion 24 may not be reliably performed.

On the other hand, in the present embodiment, as shown in FIG. 3, since the protruding electrode 16 is provided, the connection between the electrode portion 15 and the conductive portion 24 via the protruding electrode 16 is provided. Conduction can be reliably performed.

As a method for forming the protruding electrodes 16, a method of forming a gold stud bump using a wire bonder is easy, but a method of forming a solder bump may be used.

As a conductive material for forming the conductive portion 24, for example, a conductive resin can be used. As the conductive resin, for example, a known conductive paste in which conductive fine particles such as silver are dispersed in a liquid resin binder such as epoxy can be used. After filling the connection hole 23 provided in the substrate 21 with such a conductive resin, and solidifying the same, the conductive portion 24 can be formed.

Here, an example of a method for forming the conductive portion 24 will be described with reference to FIGS. In this method, as shown in FIG. 4, the substrate 11 on which the protruding electrodes 16 are formed in advance and the substrate 21 are joined, and then, as shown in FIGS. The connection hole 2 provided in the substrate 21 by using a printing method or the like.
3 to form a conductive portion 24. 4 and 5
The squeegee 29 is used to connect the conductive resin 28 to the connection hole 2.
FIG.

When the conductive resin 28 is buried in the connection hole 23 as described above, although not particularly shown in FIGS. A portion other than the connection hole 23 may be covered using a metal mask or the like, and then the paste-like conductive resin 28 may be embedded in the connection hole 23 and solidified. In this case, if the metal mask is appropriately arranged, the surface electrode 25 connected to the conductive portion 24 can be formed at the same time.

As a method of embedding the conductive resin 28 in the connection hole 23, the conductive resin 28 is applied to the entire surface of the substrate 21, the conductive resin 28 is embedded in the connection hole 23, and after being solidified, The surface of the conductive resin 28 may be polished to remove the conductive resin 28 other than the portion embedded in the connection hole 23.

In the present embodiment, since the protruding electrodes 16 are provided, the conductive resin 28 is not sufficiently buried in the connection holes 23, and as shown in FIG. Even if it does not reach, the conduction between the electrode portion 15 and the conductive portion 24 can be reliably performed via the protruding electrode 16.

Next, another example of a method of forming the conductive portion 24 will be described with reference to FIGS. In this method, as shown in FIG.
A substrate 21 in which a conductive resin 28 to be 4 is embedded is prepared, and this substrate 21 is bonded to the substrate 11 on which the protruding electrodes 16 are formed, as shown in FIG. in this way,
The substrate 21 is pressed against the substrate 11 with an appropriate pressure, and the bonding layer 1 is pressed.
By joining the substrate 21 and the substrate 11 through the protrusion 9, the protruding electrode 16 is pressed against the conductive portion 24 made of a conductive resin 28, and a reliable electrical connection between the protruding electrode 16 and the conductive portion 24 A connection is made. As a method of embedding the conductive resin 28 in the connection hole 23 in advance, for example, a method such as a printing method as shown in FIGS. 4 and 5 may be used.

The surface electrode 25 electrically connected to the conductive portion 24 can be easily formed by forming a conductive resin pattern by, for example, a printing method.

Next, the operation of the infrared detector according to this embodiment will be described. In the infrared detector according to the present embodiment, infrared light to be detected enters from the back surface (the upper surface in FIG. 1) of the substrate 11 and enters the infrared detection element 14 through the cavity 12. An output signal of the infrared detecting element 14 is extracted to the outside from the back surface of the substrate 21 via the electrode portion 15, the protruding electrode 16, the conductive portion 24, and the surface electrode 25.

The infrared detector according to the present embodiment has a first
In the form of a chip-size package formed by bonding the substrate portion 10 and the second substrate portion 20 to each other, which is easier than a conventional infrared detector packaged using a metal case. In addition, the size and cost can be reduced. In addition, the output signal of the infrared detecting element 14 can be directly extracted to the outside from the surface electrode 25 formed on the substrate 21. Therefore, the infrared detector according to the present embodiment can be used as it is as a surface mount component.

In the infrared detector according to the present embodiment, the protruding electrode 16 is provided on the electrode portion 15 connected to the infrared detecting element 14 on the first substrate portion 10 and the second substrate portion 20 is provided with the protruding electrode 16. A conductive material is buried in the connection hole 23 of the substrate 21 to form a conductive portion 24, and the conductive portion 24 is connected to the protruding electrode 16. Therefore, according to the infrared detector according to the present embodiment, the cavity 12,
The output signal of the infrared detection element 14 can be easily and reliably extracted to the outside without impairing the airtightness of the sensor 22, and the reliability of the portion for extracting the output signal of the infrared detection element 14 to the outside can be increased. Together with the infrared detecting element 1
The structure of the portion for extracting the output signal of No. 4 to the outside is simple, and the manufacture is easy.

From the above, according to the present embodiment,
An infrared detector that can be reduced in size, reduced in cost, and improved in productivity and can be used as a surface mount component can be realized.

[Second Embodiment] FIG. 8 is a sectional view showing a configuration of an infrared detector according to a second embodiment of the present invention. The infrared detector according to the present embodiment includes a first substrate unit 110 and a second substrate unit 12 disposed below the first substrate unit 110 and joined to the first substrate unit 110.
0, and a third substrate unit 130 disposed above the first substrate unit 110 and joined to the first substrate unit 110.

The first substrate section 110 has a substrate 111. The substrate 111 has a cavity 11 penetrating from the front surface (the lower surface in FIG. 8) to the rear surface (the upper surface in FIG. 8).
2 are provided. Above the opening on the lower side of the cavity 112, an infrared detecting element 114 supported by a support 113 having a bridge structure or a diaphragm structure provided on the lower surface side of the substrate 111 is provided. Also, substrate 1
An electrode 115 connected to the infrared detection element 114 and a plurality of protruding electrodes 116 connected to the electrode 115 and protruding downward are provided on the lower surface side of 11.

The second substrate section 120 includes an insulating substrate 121
It has. The substrate 121 includes the first substrate unit 11
A non-penetrating hollow part 122 that is open only on the first substrate part 110 side is provided in a portion facing the infrared detecting element 114 and the hollow part 112 of the first substrate part 110. Also, the substrate 121
A connection hole 123 penetrating the substrate 121 is formed in a portion of the first substrate portion 110 facing the protruding electrode 116.

In the connection hole 123, a conductive portion is formed by burying a conductive substance. On the lower surface of the insulating substrate 121, a surface electrode 125 electrically connected to the conductive portion 124 is provided. This surface electrode 12
Reference numeral 5 is used as an output terminal for extracting an output signal of the infrared detection element 114 to the outside, and has an appropriate shape.

The substrate 111 and the substrate 121 are
Are joined at portions other than the cavities 112 and 122 and the connection hole 123. Thereby, the cavity 112,
122 is hermetically sealed to the surrounding atmosphere.

The method of joining the substrate 111 and the substrate 121 is the same as in the first embodiment. Further, in the infrared detector according to the present embodiment, the output signal of infrared detecting element 114 is extracted to the outside via electrode portion 115, protruding electrode 116, conductive portion 124, and surface electrode 125. The configuration and the method of forming a portion for extracting the output signal of the infrared detection element 114 to the outside are the same as those in the first embodiment.

The third substrate section 130 has a substrate 131 that transmits infrared light. This substrate 131 is used for bonding layer 12
9 is joined to the substrate 111 at a portion other than the cavity 112. As a material of the substrate 131, single crystal silicon, polycrystalline silicon, single crystal germanium, polycrystalline germanium, infrared transmitting glass, infrared transmitting resin, or the like can be used. As a method for joining the substrate 111 and the substrate 131, the substrate 11 and the substrate 2 in the first embodiment are used.
As in the case of bonding with No. 1, methods such as anodic bonding, resin bonding, and low-melting glass bonding can be used.

In the infrared detector according to the present embodiment, the infrared light to be detected enters from the substrate 131 side, enters the infrared detecting element 114 through the cavity 112. The infrared antireflection films 132 and 13 are formed on both surfaces of the substrate 131.
3 may be provided to reduce the reflection loss of infrared light on both surfaces of the substrate 131 and increase the sensitivity of the infrared detector to infrared light. Further, an infrared filter film that selectively transmits infrared light of a specific wavelength may be provided instead of the infrared antireflection film. The configurations of the infrared antireflection film and the infrared filter film are the same as those in the first embodiment.

In the infrared detector according to the present embodiment having the above-described configuration, compared with the infrared detector according to the first embodiment, a new third substrate portion 130 (substrate 13) is provided.
1) is required, and the first substrate 110
A step of bonding to (substrate 111) is required. But,
The infrared detector according to the present embodiment has the following three advantages as compared with the infrared detector according to the first embodiment. The first point is that a material other than the infrared transmitting material can be used as the material of the substrate 111 of the first substrate unit 110. The second point is that an arbitrary infrared transmission characteristic can be obtained by selecting the material of the substrate 131 of the third substrate unit 130. The third point is
Infrared antireflection films 132, 13 on both the front and back surfaces of the substrate 130
3 or that an infrared filter film can be formed, so that the characteristics of the infrared detector can be further improved.

Other configurations, operations, and effects of the present embodiment are the same as those of the first embodiment.

[Third Embodiment] FIG. 9 is a sectional view showing a configuration of an infrared detecting apparatus according to a third embodiment of the present invention. The infrared detection device according to the present embodiment includes an insulating substrate 201 having high thermal conductivity. The substrate 201 has a plurality of end electrodes for taking out output signals of an infrared detector and a temperature sensor element to be described later from a position near the end on the upper surface to a position near the end on the lower surface via the side portion. 202 is provided. A wiring portion 203 made of a conductive material and connected to the end electrode 202 is provided on the upper surface of the substrate 201.

On the upper surface of the substrate 201, a surface-mounted infrared detector 205 and a temperature sensor element 206 for detecting the temperature of the substrate 201 as a reference temperature are mounted. Each of the infrared detector 205 and the temperature sensor element 206 has a plurality of terminals. Each terminal is electrically connected to the end electrode 202 directly or via the wiring section 203.

In the manufacturing process of the infrared detector according to the present embodiment, the infrared detector 205 and the temperature sensor element 2
06 is surface-mounted on the upper surface of the substrate 201,
An underfill resin 207 is applied to improve mechanical bonding and thermal bonding between the infrared detector 205 and the temperature sensor element 206 and the substrate 201. Further, the whole is coated with an insulating resin 208 as needed.

The substrate 201 has only to be excellent in mechanical strength, large in thermal conductivity, high insulative, and capable of forming the end electrode 202 and the wiring portion 203 on the upper, lower, and side surfaces. As the substrate 201, for example, an alumina-based ceramic substrate, an aluminum nitride ceramic substrate, or a substrate obtained by subjecting an aluminum plate to an alumite treatment is used.

When a ceramic substrate is used as the substrate 201, the end electrodes 202 and the wiring portions 203 can be easily formed by, for example, a known method of forming a conductive paste pattern by a printing method. When a substrate obtained by subjecting an aluminum plate to an alumite treatment is used as the substrate 201, the end electrodes 202 and the wiring portions 203 may be formed, for example, by bonding a copper foil to the substrate after the alumite treatment and etching the copper foil. And can be formed by patterning.

The thickness of the substrate 201 is 0.5 to 3 m
A value of about m is desirable because good characteristics can be obtained in terms of thermal uniformity and mechanical strength inside the substrate.

As the surface-mounted infrared detector 205, it is desirable to use the infrared detector according to the first or second embodiment of the present invention.

As the underfill resin 207, LS
I, an epoxy resin used for flip-chip mounting, an infrared detector 205, a temperature sensor element 206, or the like.
Anisotropic conductive paste can be used so as to also serve as an electrical connection between the end electrode 202 and the wiring portion 203.

As the temperature sensor element 206, a surface mount type NTC chip thermistor is preferable because of its excellent thermal responsiveness, accuracy and reliability.

For protecting the surface of the substrate 201 and protecting the infrared detector 205 and the temperature sensor element 206,
It is preferable to apply the insulating resin 208 to the entire surface of the substrate 201 with a dispenser or the like. This insulating resin 2
As 08, it is preferable to use a high thermal conductive insulating resin in which a good thermal conductive filler is dispersed, since the thermal coupling between the infrared detector, the temperature sensor element, and the insulating substrate can be improved. . In this case, the infrared detector 205
It is necessary to apply this resin to the infrared detection surface 205a so as not to adhere thereto.

As described above, in the infrared detecting device according to the present embodiment, the substrate 20 having high thermal conductivity and insulation is used.
An infrared detector 205 and a temperature sensor element 206 for detecting a reference temperature are densely mounted on the device 1. Therefore, according to the infrared detector according to the present embodiment, compared with the case where the infrared detector 205 and the temperature sensor element 206 are directly mounted on a printed circuit board or the like, the infrared detector 205 and the The temperature difference between the sensor elements 206 is reduced, and highly accurate infrared detection can be performed.

According to the present embodiment, the substrate 201
And the infrared detector 205 are thermally satisfactorily coupled with each other, and the heat capacity becomes large as a whole. Therefore, the transitional temperature change at the time of the ambient temperature change becomes gentle, and the generation of a false signal due to the temperature change of the infrared detector 205 is prevented. Can be prevented.

By the way, an infrared detector using a single crystal substrate such as silicon as a substrate on which an infrared detecting element is disposed has a low mechanical strength. Therefore, when such an infrared detector itself is used as a surface mounting component, problems such as chipping are likely to occur, handling is difficult, and there is a possibility of damage due to warpage of the printed circuit board. However, in the infrared detection device according to the present embodiment, such a problem does not occur because the infrared detector 205 is mounted on the substrate 201 having high mechanical strength.

When a ceramic substrate or a substrate obtained by subjecting an aluminum plate to alumite treatment is used as the substrate 201, the substrate 201 can be realized at low cost, and the end electrode 202 and the wiring can be easily mounted on the substrate 201. The part 203 can be formed. Therefore, the problem of the conventional packaging using the metal holder and the flexible printed circuit board can be solved.

According to the present embodiment, the infrared detector 205 and the temperature sensor element 206 are mounted on the substrate 201 having high thermal conductivity and insulation to constitute the infrared detector. The size of the device can be reduced. In addition, the infrared detection device itself configured in this manner is
Since it can be handled as a surface-mounted electronic component, handling of the infrared detection device, mounting on a printed circuit board, and the like are facilitated, reliability is improved, and cost reduction can be achieved.

In this embodiment, as shown in FIG. 10, on the substrate 201, in addition to the infrared detector 205 and the temperature sensor element 206, amplification and signal processing of the output signal of the infrared detector 205 are performed. A signal processing circuit element 210 for performing the operation may be mounted. With such a configuration, the infrared detector 20 near the infrared detector 205 can be used.
5 can be directly amplified, so that the infrared detection device is resistant to inductive noise from the outside. Further, since the circuit element 210 is mounted on the high thermal conductive and insulating substrate 201, the temperature of the circuit element 210 is stabilized, and the generation of thermoelectromotive force due to dissimilar metal bonding of the wiring portion inside the circuit is suppressed, and the error Infrared detection can be performed. For these reasons, the accuracy of the infrared detection device including the signal processing circuit element 210 can be improved.

The present invention is not limited to the above embodiments, and various changes can be made.

[0090]

As described above, claims 1 to 4
According to any one of the infrared detectors described above, the first substrate unit and the second substrate unit are joined to form an infrared detector, and the first substrate is provided with a protruding electrode, By connecting a conductive portion made of a conductive substance embedded in the connection hole formed in the substrate 2 to the protruding electrode, the output signal of the infrared detection element can be directly taken out to the outside, so that infrared detection It is possible to reduce the size, cost, and productivity of the container.

Further, according to the infrared detecting device of the fifth or sixth aspect, the surface mounting type infrared detector and the temperature sensor element are mounted on the insulating substrate having high thermal conductivity. This has the effect of enabling downsizing, cost reduction, and high precision.

Further, according to the infrared detecting device of the sixth aspect, since the circuit element is further mounted on the substrate, it is possible to improve the accuracy of the infrared detecting device including the circuit element.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an infrared detector according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a conductive material is filled in a connection hole in a case where there is no protruding electrode in FIG.

FIG. 3 is a cross-sectional view showing a connection state between a protruding electrode and a conductive portion according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating an example of a method of forming a conductive portion according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating an example of a method of forming a conductive portion according to the first embodiment of the present invention.

FIG. 6 is an explanatory view showing another example of a method for forming a conductive portion according to the first embodiment of the present invention.

FIG. 7 is an explanatory view showing another example of a method for forming a conductive portion according to the first embodiment of the present invention.

FIG. 8 is a cross-sectional view illustrating a configuration of an infrared detector according to a second embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating a configuration of an infrared detection device according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view showing an example in which a signal processing circuit element is further mounted on a substrate in the infrared detection device according to the third embodiment of the present invention.

[Explanation of symbols]

10: first substrate portion, 11: substrate, 12: hollow portion, 13
... Support, 14 ... Infrared detecting element, 15 ... Electrode part, 16
... projecting electrodes, 17 ... infrared antireflection film, 19 ... joining layer, 20 ... second substrate part, 21 ... insulating substrate, 22 ... cavity part, 23 ... connection hole, 24 ... conductive part, 25 ... surface electrode .

Claims (6)

[Claims] A first substrate portion and a second substrate portion arranged and joined to face each other, wherein the first substrate portion has one surface facing the second substrate portion; A first substrate having a cavity formed therein, an infrared detecting element disposed on the cavity on the one surface side of the first substrate, and the one surface of the first substrate And a protruding electrode for taking out the output signal of the infrared detection element to the outside, wherein the second substrate portion has a cavity formed in a portion facing the infrared detection element, A through hole is formed at a portion facing the protruding electrode, and an insulating second hole is disposed and joined to face the first substrate.
An infrared detector comprising: a substrate as described above; and a conductive portion made of a conductive material embedded in the connection hole and electrically connected to the protruding electrode. 2. The first substrate has an infrared transmission property,
The cavity of the first substrate does not penetrate the first substrate,
2. The infrared detector according to claim 1, wherein the opening is provided only on the one surface. 3. The method according to claim 2, wherein the first substrate is made of single-crystal silicon having a (100) plane orientation, and a cavity of the first substrate is formed by anisotropic etching. Infrared detector. 4. A cavity of the first substrate penetrates the first substrate, and an infrared detector is further arranged on the first substrate on a side opposite to the second substrate. 2. The infrared detector according to claim 1, further comprising a third substrate having an infrared transmitting property and joined to the third substrate. 5. An insulating substrate having a high thermal conductivity and an insulative substrate; a surface-mounted infrared detector mounted on the substrate; and a temperature sensor element mounted on the substrate and detecting a temperature of the substrate. And an electrode formed on the substrate for extracting an output signal of the infrared detector and the temperature sensor element to the outside. The infrared detector according to any one of claims 1 to 4, An infrared detector, which is a detector. 6. The infrared detection device according to claim 5, further comprising a circuit element mounted on said substrate.