JP2000236110A - Infrared emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mount an element on a circuit by a single piece for reducing the cost. SOLUTION: An infrared emitting element is provided with an element substrate 31, having a hole 32 which passes through the substrate from one face to an opposite face, a p-type semiconductor layer 33 which is formed on one face of the substrate 31 and has a bridge-like heating section 33a stretched over the opening face of the hole 32 and emits infrared rays from the heating section 33a, when it is supplied with power, a pair of electrodes 35, 36 formed on the p-type semiconductor layer 33 for supplying power to the heating section 33a, a pair of terminals 41 for supplying power which are formed on an end part of one face of the substrate 31 and the connected to the electrodes 35, 36 respectively, and a reinforcing substrate 43 fixed on the opposite face of the substrate to reinforce the substrate. Due to this structure, the entire element is reinforced by the reinforcing substrate 43. Moreover, since the terminals 41 are formed on an end part of one face of the element substrate 31, the element can be easily assembled into a circuit or an equipment as a single piece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for simplifying a structure, increasing productivity and reducing costs in an infrared radiating element that radiates infrared rays from a heat generating portion formed of a semiconductor on an element substrate such as silicon.

[0002]

2. Description of the Related Art In addition to being used as a light emitting element, an infrared emitting element is also used as a light source of a gas analyzer utilizing infrared absorption.

[0003] The infrared light source conventionally used for the infrared gas analysis is a light source in which a heater is embedded in ceramic or a material in which a platinum or tungsten filament is sealed in a glass tube. In addition, there is a problem that the change with time is large, and a high-speed mechanical chopper is separately required when intermittently emitting infrared rays (chopping) due to a large heat capacity.

In order to solve this problem, a so-called microbridge structure is provided in which a heating section made of semiconductor is provided on one surface of an element substrate such as silicon by using micromachining technology, and the heating section is energized to emit infrared rays. Various infrared radiation elements have been proposed.

FIGS. 21 and 22 show known infrared radiating elements having the microbridge structure.

The infrared radiating element 10 is formed on one side 1 of a silicon element substrate 11 by micromachining technology.
A depression 12 is provided on the side of 1a, a heating section 13 made of a p-type semiconductor is provided across the opening surface of the depression 12, and electrodes 14 and 15 are provided at both ends of the heating section 13.

In this infrared radiation element 10, the electrodes 14,
When a voltage is applied between 15 and 15, the heat generating portion 13 generates heat and emits infrared rays.

The infrared radiation element 10 having such a microbridge structure has an advantage that high-speed chopping can be performed because the element shape is small and the heat capacity is small.

However, it is inconvenient to mount the infrared radiating element 10 formed on the silicon element substrate 11 as it is in various devices, and in practice, as shown in FIG. Are mounted on the case substrate 20 and the upper ends of the lead terminals 21 and 22 fixed so as to penetrate the case substrate 20 and the electrode 1 of the infrared radiation element 10.
After connecting (bonding) between 4 and 15 with gold wires 23 and 24, respectively, the cylindrical case 25 is covered to protect the infrared radiating element 10, and power can be supplied from the terminals 21 and 22.

The upper surface of the cylindrical case 25 is covered with a window 26 made of a material having a high transmittance to infrared rays (for example, sapphire), and infrared rays emitted from the infrared radiating element 10 pass through the window 26. Radiated to the outside.

[0011]

However, as described above, the infrared radiating element 10 is mounted on the case substrate 20, and wiring between the electrodes 14, 15 and the lead terminals 21, 22 is performed. The infrared radiator, which is completed by covering the
Since the number of components is increased, including processes such as bonding and case fixing, the cost is increased.

An object of the present invention is to solve the above problem and to provide an infrared radiation element which can be mounted on a circuit as a single element and which realizes low cost.

[0013]

According to a first aspect of the present invention, there is provided an infrared radiating element comprising a hole penetrating from one surface to an opposite surface, or a depressed portion recessed from one surface to an opposite surface. An element substrate having: a semiconductor layer formed on the one surface side of the element substrate, having a bridge-like heating portion crossing the opening surface of the hole or the depression, and radiating infrared rays from the heating portion when energized, A pair of electrodes formed on the semiconductor layer to supply current to the heat generating portion, and a pair of power supply electrodes formed at ends on the one surface side of the element substrate and connected to the pair of electrodes, respectively. And a reinforcing substrate fixed to the opposite surface of the element substrate for element reinforcement.

According to a second aspect of the present invention, there is provided the infrared radiating element according to the first aspect, wherein the one side of the element substrate has an insulating frame formed so as to surround the heat generating portion. And a cover having an insulating property and formed to cover an opening surface of the frame-shaped body, the body having an infrared transmission property.

According to a third aspect of the present invention, there is provided the infrared radiating element according to the first or second aspect, wherein at least a portion of one side of the reinforcing substrate that closes the hole of the element substrate or The bottom of the depressed portion of the element substrate is formed so as to exhibit a high reflectance to infrared rays.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. In the following description of each embodiment, the same components will be denoted by the same reference numerals and description thereof will be omitted.

FIGS. 1 and 2 show an infrared radiation element 30 according to a first embodiment of the present invention. The element substrate 21 of the infrared radiation element 30 is, for example, 25 mm in n-type silicon.
It is formed in a horizontally long rectangular shape of about × 10 mm, and a hole 32 penetrating in a trapezoidal shape is provided on one end side from the one surface 31a side to the opposite surface 31b side.

On the one surface 31a side of the element substrate 31, a p-type semiconductor layer 33 is formed in a substantially h shape. p-type semiconductor layer 33
Is provided with a heat generating portion 33a formed so as to cross the center of the opening surface of the hole 32 on one surface 31a side of the element substrate 31. Both ends 33b and 33c of the p-type semiconductor layer 33
Is provided with a pair of electrodes 35 and 36 made of a metal material (such as gold or aluminum).

Both ends 33b, 33c of the p-type semiconductor layer 33
Is wide and has a low resistance value and is in contact with the element substrate 31, whereas the heating portion 33 a is narrow and has a high resistance value and is far from the element substrate 31, so that a voltage is applied between the electrodes 35 and 36. When a current flows through the p-type semiconductor layer 33, only the heat generating portion 33a generates heat and emits infrared rays.

One surface 31a of the element substrate 31 and the electrode 3
The surface excluding the junction between 5, 36 and the p-type semiconductor layer 33 is:
It is covered with a silicon oxide film 37 (not shown in FIG. 1) which has an insulating property and promotes the emission of infrared rays.

That is, when the thickness of the oxide film is merely about 0.1 μm for the purpose of merely protecting the surface, as shown in FIG. 3, the thickness of the silicon oxide film is set to a constant value (approximately 1 μm).
Since it was found that the emissivity of infrared rays was significantly increased by the above, in the infrared radiating element 30 of this embodiment,
At least the thickness of the silicon oxide film 37 on the surface of the heating section 33 is set to 0.4 μm or more (for example, about 1 μm),
The protection of the surface is strengthened and the radiation efficiency of infrared rays is improved.

On the surface of the silicon oxide film 37, connection patterns 38, 3 made of a metal material (such as gold or aluminum) are formed.
9 are formed. One connection pattern 38 has one end 38 a connected to the electrode 35 and the other end 38 b extending to the other end of the element substrate 31.

The other connection pattern 39 has one end 39
a is connected to the electrode 36, and the other end 39 b extends to the other end of the element substrate 31.

The other ends 38b, 3 of the connection patterns 38, 39
On the upper surface of 9b, power supply terminals 40 and 41 are formed by solder or the like.

The terminals 40 and 41 extend in parallel to the short side edge of the element substrate 31 with a predetermined gap. The terminal spacing between the terminals 40 and 41 is, for example, about 5.1 mm (2/1
0 inch) or about 7.6 mm (3/10 inch).

On the other hand, on the opposite surface 31b side of the element substrate 31, a reinforcing substrate 43 having the same outer shape as the element substrate 31 and having insulation properties is fixed for element reinforcement. The reinforcing substrate 43 is made of a material having good heat conductivity such as alumina or sapphire, and has a thickness of 200 μm or more in order to make the entire thickness of the infrared radiation element 30 about 0.5 mm to 1 mm, which can be easily handled as a single element. It has a thickness of 500 μm.

In a portion of the upper surface 43a of the reinforcing substrate 43 which forms the bottom of the hole 32 of the element substrate 31, a reflection film 44 (for example, a gold thin film or an aluminum foil) having a high reflectance to infrared rays is provided. Have been. The infrared radiation emitted from the heat generating portion 33a to the reinforcing substrate 43 side is reflected by the reflection film 44 to one surface side of the element substrate 31, so that the radiation efficiency of the infrared radiation is increased.

This infrared radiation element 30 can be easily manufactured by micromachining technology. Hereinafter, the manufacturing method will be briefly described. In the following description, one infrared radiating element 30 will be described, but actually, a plurality of infrared radiating elements 3 are arranged on a large element substrate.
0 are simultaneously formed.

First, an n ⁻ -type single-crystal semiconductor substrate having a specific resistance of 8 to 15 Ω · cm and a plane orientation (100) is prepared as a base material of an element substrate (hereinafter, this base material is referred to as an element substrate 31). By subjecting one surface of the element substrate 31 to a thermal oxidation process, a thermal oxide film having a thickness of about 0.7 μm is formed.
The thermal oxide film in the region where the mold semiconductor layer 33 is to be formed is removed by photolithography.

Next, one surface of the element substrate 31 is ion-implanted at a high concentration, for example, at a dose of 4.0.
Acceleration voltage of 175 kV with boron of × 10 ¹⁶ ions / cm ²
And annealing is performed in a high-temperature nitrogen gas atmosphere at 1100 to 1200 ° C. for about 10 to 60 minutes, and a p-type semiconductor layer 33 having a desired thickness (for example, 5 μm) is formed in a region where the oxide film is removed. Is formed, the thermal oxide film on the surface of the element substrate 31 is removed.

Next, a thermal oxide film 37 having a thickness of about 0.4 μm to 1 μm is formed on one surface side of the element substrate 31 by thermal oxidation.
(The oxide film 37 is used to protect the surface of the device and promote the emission of infrared rays.) The thermal oxide film in the electrode formation regions at both ends of the p-type semiconductor layer 33 is removed by photolithography. After forming a thin film of gold, aluminum, or the like on the entire one surface side of the substrate 31 by a vacuum evaporation method, the thin films other than the electrode formation region and the connection pattern formation region are removed by patterning, and the electrodes 35 and 36 and the connection pattern 3 are removed.
8, 39 are formed.

Next, a hole 32 penetrating from the lower surface side of the heat generating portion 33a to the opposite surface side of the element substrate 31 is formed by utilizing the anisotropic etching characteristics of an ammonia solution or the like and the carrier concentration dependence of the etching rate. .

Next, one surface 43a of the reinforcing substrate 43 in a vacuum
Is stacked on the opposite surface of the element substrate 31 and a high voltage (about 500 V) is applied between the electrode 35 or the electrode 36 and the opposite surface 43b of the reinforcing substrate 43 to reduce the entire element to 200 to 30.
By heating to 0 ° C., one surface 43 a of the reinforcing substrate 43 is fused to the opposite surface of the element substrate 31.

The other ends 3 of the connection patterns 38 and 39
The terminals 40 and 41 are formed by evaporating solder on the upper surfaces of 8b and 39b.

Finally, the element substrate is divided into chips by a dicer to obtain the infrared radiation element 30 alone.

The infrared radiation element 3 configured as described above
Numeral 0 indicates that the entire element is reinforced by the reinforcing substrate 43, and the terminal 40,
Since the element 41 is formed, the element can be easily incorporated into a circuit or a device by itself.

For example, as shown in FIG.
The infrared radiation element 30 can be mounted on the connector 46 mounted thereon.

Also, as shown in FIG. 5, the terminals 40 of the infrared radiating element 30 are mounted on the circuit board 45 without using a connector.
41 can also be directly soldered.

Also, without directly mounting on the circuit board, FIG.
As shown in (1), it is also possible to solder the lead wire 47 to the terminals 40 and 41 of the infrared radiation element 30 for use.

As described above, the infrared radiating element 3 of the embodiment
No. 0 does not need to be mounted on a case unlike the conventional device, and can be used as a single device. Therefore, the manufacturing cost can be greatly reduced, and the product cost can be significantly reduced.

Further, in the infrared radiation element 30, the power supply terminals 40 and 41 are provided at one end of the heat generating portion 33a in parallel with the heat generating portion 33a, but this does not limit the present invention. For example, the infrared radiation element 50 shown in FIGS.
The p-type semiconductor layer 33 is H-shaped (or U-shaped) as shown in FIG.
And electrodes 35 and 36 are provided at both ends thereof.
Terminals 40 for power supply are connected to the distal ends of the connection patterns 38 and 39 extending from the fifth and 36 in a direction perpendicular to the heat generating portion 33a.
41 may be provided. Even in this case, the interval between the terminals 40 and 41 is set in consideration of attachment to the connector.

In the infrared radiating elements 30 and 50, the surface of the heat generating portion 33a is protected only by the silicon oxide film 37. However, the infrared radiating elements 60 and 50 shown in FIGS.
The surface may be covered with sapphire or the like.

The element substrate 61 of the infrared radiation element 60
Is made of n ⁻ -type silicon and formed in a horizontally long rectangular shape of, for example, about 40 mm × 15 mm, and has a trapezoidal hole 62 at one end from the one surface 61 a to the opposite surface 61 b.

On one surface 61a of the element substrate 61, a p-type semiconductor layer 63 is formed in a horizontal U-shape. The p-type semiconductor layer 63 has a hole 6 on one surface 61 a side of the element substrate 61.
A heat generating portion 63a that crosses the center of the opening surface of the second heat generating portion 33;
The folded portion 6 formed so as to return to the other end of the element substrate 61 along the periphery of the hole 62 from the front end (the left end in FIG. 9) of “a”.
3b. The width of the turned-up portion 63b is set so that the heat-generating portion 6b does not generate a large amount of heat due to energization.
3a is set to be larger than 3a.

A pair of electrodes 65 and 66 made of a metal material are provided on both end surfaces of the p-type semiconductor layer 63. When a voltage is applied between the electrodes 65 and 66, the heat generating portion 63a generates heat, and infrared rays are emitted. Radiate.

The surface from the electrodes 65 and 66 to the other edge of the element substrate 61 is covered with a silicon oxide film 67.

On the surface of the silicon oxide film 67, connection patterns 68 and 69 made of a metal material are formed.
One connection pattern 68 has one end connected to the electrode 65 and the other end extending to the other end of the element substrate 61.

The other connection pattern 69 has one end connected to the electrode 66 and the other end extending to the other end of the element substrate 61.

Power supply terminals 70 and 71 are formed on the upper surfaces of the other ends of the connection patterns 68 and 69. The terminals 70 and 71 are parallel to the element substrate 6 with a predetermined gap.
1 to one edge. The terminal interval between the terminals 70 and 71 is set to about 5.1 mm (2/10 inch), about 7.6 mm (3/10 inch), or the like so that the terminals 70 and 71 can be attached to a connector having a 1/10 inch pitch as described above. ing.

On the upper surface on the other end side of the element substrate 61, a frame 73 formed in a rectangular frame shape with silicon, glass or the like is fixed so as to surround the heat generating portion 63a.

The open upper surface of the frame 73 is covered with a flat cover 74 made of sapphire, glass or the like having a high transmittance to infrared rays.

On the other hand, a reinforcing substrate 75 having the same outer shape as the element substrate 61 and having insulation properties is fixed to the opposite surface 61b of the element substrate 61 for element reinforcement. The reinforcing substrate 75 is made of a material having good heat conductivity, such as alumina or sapphire, and has a thickness of 200 μm to 500 μm. Of the upper surface 75a of the reinforcing substrate 75, the element substrate 6
A reflection film 76 (for example, a gold thin film or an aluminum foil) having a high reflectance to infrared rays is provided in a portion forming the bottom of one hole 62.

The infrared radiating element 60 can also be easily manufactured by micromachining technology. Less than,
The manufacturing method will be described briefly. In the following description, one infrared radiating element 60 will be described, but actually, a plurality of infrared radiating elements 60 are simultaneously formed on a large element substrate.

First, an n ⁻ -type single crystal semiconductor having a plane direction (100) having a specific resistance of 8 to 15 Ω · cm is prepared as an element substrate 61, and one side of the element substrate 51 is subjected to a thermal oxidation treatment to obtain a 0.7 μm Form a thermal oxide film of about the thickness,
The thermal oxide film in the region where the p-type semiconductor layer is to be formed is removed by photolithography.

Next, one surface of the element substrate 61 is ion-implanted at a high concentration, for example, at a dose of 4.0.
Acceleration voltage of 175 kV with boron of × 10 ¹⁶ ions / cm ²
And annealing is performed in a high-temperature nitrogen gas atmosphere at 1100 to 1200 ° C. for about 10 to 60 minutes to form a p-type semiconductor layer 63 having a desired thickness (for example, 5 μm) in a region where the oxide film is removed. Then, the thermal oxide film on the surface of the element substrate 61 is removed.

Next, a silicon oxide film 67 having a thickness of about 0.4 μm to 1 μm is formed on one surface side of the element substrate 61 by thermal oxidation, and the thermal oxide film in the electrode formation region is removed by photolithography. Then, after forming a thin film of gold, aluminum, or the like on the entire surface of the element substrate 61 by a vacuum evaporation method, the thin films other than the electrode formation region and the connection pattern formation region are removed by patterning, and the electrodes 65 and 66 are formed.
And connection patterns 68 and 69 are formed.

Next, a hole 62 penetrating from the lower surface side of the heat generating portion 63a to the opposite surface side of the element substrate 61 is formed by utilizing the anisotropic etching characteristics of an ammonia solution or the like and the carrier concentration dependence of the etching rate. .

Next, the frame 73 is attached to the element substrate 61 in a vacuum.
The cover 74 on the frame 73.
The cover 74 and the reinforcing substrate 7 are placed in a state where one surface 75a of the reinforcing substrate 75 is placed on the opposite surface of the element substrate 61.
5 is heated to 200 to 300 ° C. by applying a high voltage to the surface 85b opposite to the surface 5b between the one surface of the element substrate 61 and the lower surface of the frame 73, and The space between the end surface and the lower surface of the cover 74 and the space between one surface 75a of the reinforcing substrate 75 and the opposite surface of the element substrate 61 are fused.

Finally, the connection patterns 68 and 69
The solder is deposited on the upper surfaces of the other ends 68b and 69b of the
0 and 71 are formed.

The infrared radiating element manufactured in this manner is divided into individual chips by a dicer and becomes a single product.

In this infrared radiation element 60, the reinforcing substrate 7
5 and the terminals 70 and 71 are formed on the edge of one side of the element substrate 61, so that the connector is mounted as shown in FIGS.
Direct mounting and wiring with lead wires are possible, and the element can be easily incorporated into a circuit or device as a single item.

Since the surface of the heat generating portion 63a is covered with the cover 74, the infrared radiating element 60 is less likely to be deteriorated by dirt on the surface of the heat generating portion 63a and has high reliability.

As described above, the infrared radiation element 6 of the embodiment
The 0 does not need to be mounted on the case like the conventional device, and can be used as a single device, so the manufacturing cost can be greatly reduced, and the cost can be significantly reduced while maintaining high reliability. Becomes

The infrared radiation elements 30, 50, 6
In the case of 0, the heat generating sections 33a and 63a
While the infrared radiation radiated to the side is reflected to one surface side of the element substrates 31 and 61 by the reflection films 44 and 76, the reinforcing substrate 4
In the case where 3, 75 itself has a high reflectance to infrared rays, the reflection films 44, 76 can be omitted.

As shown in FIG. 11A and FIG. 11B of the sectional view taken along the line EE of FIG. 11, a concave portion 48 is formed on one surface side of the reinforcing substrate 43 (75). When it has a high reflectance to infrared rays), the concave portion 48
(In the case where the reinforcing substrate itself does not have a high reflectance with respect to the infrared light), the infrared light radiated from the heat generating portion 33a (63a) to the reinforcing substrate 43 (75) side is provided. The concave portion 48 or the reflection film 49 can efficiently reflect light in a direction orthogonal to one surface of the element substrate 31 (61).

In the above embodiment, the device substrates 31 and 6
Although the case where the holes 32 and 62 are provided in 1 has been described, the present invention can be similarly applied to an infrared radiation element in which a depression is provided in the element substrate.

For example, as in the infrared radiation element 80 shown in FIGS. 12 and 13, a depression 82 is provided in the element substrate 31 ′, and the heat generating part 33 a of the p-type semiconductor layer 33 is
The electrodes 35, 36 are connected to the terminals 40, 41 via the connection patterns 38, 39 even if the electrodes 35, 36 are formed so as to cross the opening surface of the depression 82 on one surface side of the element substrate 1 '. By fixing the reinforcing substrate 43 on the side, the same effect as the infrared radiation element 30 can be obtained.

Further, as in an infrared radiation element 90 shown in FIGS. 14 and 15, for example, a depression 92 is provided in an element substrate 61 ', and a heat generating portion 63a of a p-type semiconductor layer 63 is formed on one surface of the element substrate 61'. The electrodes 65 and 66 are connected to the terminals 70 and 71 via the connection patterns 68 and 69 even if the electrodes 65 and 66 are formed so as to cross the opening surface of the depression 92 on the side.
One side of the heat generating portion 63a is covered by the frame 73 and the cover 74, and the reinforcing substrate 7 is provided on the lower side of the element substrate 61 '.
By fixing 5, the same effect as that of the infrared radiation element 60 can be obtained.

A gas such as helium or argon having a high thermal conductivity is sealed in a portion of the infrared radiating element 60 and the infrared radiating element 90 which are covered with the frame 73 and the cover 74.

When the heat generating portions 33a and 63a are provided so as to cross the opening surfaces of the concave portions 82 and 92 of the element substrates 31 'and 61' like the infrared radiation elements 80 and 90, the concave portions 82 and 92 are provided. , 92, the reflection films 84 and 94 having a high reflectance with respect to infrared rays are provided, whereby the radiation efficiency of infrared rays is increased.

The method of manufacturing the infrared radiating elements 80 and 90 differs from the method of manufacturing the infrared radiating elements 30 and 60 in that the recesses 82 and 92 are etched instead of etching the holes 32 and 62. Different,
Others are the same.

Further, in the above-described embodiment, the infrared radiating element having one heat generating portion has been described. However, the present invention can be applied to an infrared radiating element having a plurality of heat generating portions.

For example, as shown in FIG. 16 and FIG. 17, a plurality of (four in the figure) holes 102a to 102d are formed in an element substrate 101 made of silicon or the like,
P-type semiconductor layer 103 formed on one surface side of element substrate 101
The heat-generating portions 103a-103 are connected in series (or in parallel) across the opening surfaces of the holes 102a-102d.
electrode 1 formed at both ends of the p-type semiconductor layer 103
The power supply terminals 110 and 111 formed at predetermined intervals on the edge of one side of the element substrate 101 are connected via connection patterns 108 and 109.

Then, a reinforcing substrate 113 for reinforcement is fixed to the opposite side of the element substrate 101. In FIGS. 16 and 17, reference numeral 107 denotes a silicon oxide film for protecting the element surface including each heat generating portion 103 and promoting infrared radiation, and reference numerals 114a to 11d denote radiation from each heat generating portion 103 to the reinforcing substrate 113 side. This is a reflection film that reflects the infrared rays to be emitted to one surface side of the element substrate 101 with high reflectance.

Also, like the infrared radiation element 120 shown in FIGS. 18 and 19, a plurality of (four in the figure) holes 122a to 122d are formed in an element substrate 121 made of silicon or the like, and one side of the element substrate 121 is formed. The heat-generating portions 123a to 123d are provided in the p-type semiconductor layer 123 formed across the openings of the holes 122a to 122d and connected in series (or in parallel), and the electrodes 12 formed at both ends of the p-type semiconductor layer 123 are formed.
5 and 126 are connected to terminals 130 and 131 formed at predetermined intervals on the edge of one side of the element substrate 121 via connection patterns 128 and 129.

The heat generating parts 123a to 123d are formed by the frame 133 and the cover 134 closing the opening.
And a reinforcing substrate 135 for reinforcement is fixed to the opposite side of the element substrate 121. In the case of the infrared radiating element 120, the infrared radiating element 6 is also used.
As in the case of 0 and 90, a gas such as helium or argon having a high thermal conductivity is sealed in a portion covered by the frame 133 and the cover 134.

Also, in FIGS. 18 and 19, reference numeral 127 is used.
Is a silicon oxide film, and reference numerals 136a to 136d are reflection films that reflect infrared rays radiated from the heat generating portions 123a to 123d toward the reinforcing substrate 135 to one surface side of the element substrate 121 with high reflectance.

The infrared radiating elements 100 and 120
In the above, one heat generating portion is provided for each hole, but a plurality of heat generating portions may be formed so as to cross the opening surface of one hole.

As described above, in the infrared radiation element having a plurality of heat generating portions, the infrared radiation power per element can be increased.

In each of the above-described infrared radiation elements, the heat generating portion is formed by the p-type semiconductor layer. However, in order to reinforce the heat generating portion, as shown in FIG. A bridge support portion 150 is formed of a semiconductor so as to cross the opening surface of the hole 32 (or depression), and the bridge support portion 150 is formed.
A heat generating portion 153 may be formed of an n-type semiconductor thereon, and the heat generating portion 153 may be supplied with power from a power supply terminal (not shown) to emit infrared rays. in this way,
By forming the heat generating portion on the bridge support portion, the strength of the heat generating portion can be increased, and the handling as a single item is further facilitated.

[0081]

As described above, according to the first aspect of the present invention,
The infrared radiating element has an electrode of a heating portion formed in a bridge shape so as to cross a hole or a depression in a semiconductor layer on one surface side of the element substrate, and a power supply electrode formed on one surface side end of the element substrate. In addition to connecting to the terminals, a reinforcing substrate is fixed on the opposite side of the element substrate.

For this reason, the step of mounting the infrared radiating element in the case again is unnecessary, and the infrared radiating element can be attached to a connector as a single element, soldered directly on a circuit board, or connected to a circuit by lead wire. As a result, the manufacturing cost can be significantly reduced, and the infrared radiation element can be provided at low cost.

Further, the infrared radiating element according to claim 2 of the present invention has an insulating frame formed on one surface side of the element substrate so as to surround the heat-generating portion, and an infrared-transmitting frame. An insulating cover formed to cover the opening surface of the body.

For this reason, since the surface of the heat generating portion is protected by the frame and the cover, the surface of the heat generating portion does not deteriorate due to dirt or the like, and the reliability is improved.

Further, the infrared radiating element according to claim 3 of the present invention is formed such that the reinforcing substrate closing the hole of the element substrate or the bottom of the depressed portion of the element substrate has a high reflectance to infrared rays. The radiation efficiency of the infrared radiation increases.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG. 1;

FIG. 3 is a diagram showing the relationship between the thickness of an oxide film and infrared emissivity.

FIG. 4 is a diagram showing a mounting example of the infrared radiation element according to the embodiment;

FIG. 5 is a view showing a mounting example of the infrared radiation element of the embodiment;

FIG. 6 is a diagram showing a mounting example of the infrared radiation element according to the embodiment;

FIG. 7 is a plan view of another embodiment.

8 is a sectional view taken along line CC of FIG. 7;

FIG. 9 is a plan view of another embodiment.

FIG. 10 is a sectional view taken along line DD of FIG. 9;

FIG. 11 is a schematic view of a case where a concave portion is provided on a reinforcing substrate.

FIG. 12 is a plan view of another embodiment.

FIG. 13 is a sectional view taken along line FF of FIG. 12;

FIG. 14 is a plan view of another embodiment.

FIG. 15 is a sectional view taken along line GG of FIG. 14;

FIG. 16 is a plan view of another embodiment.

FIG. 17 is a sectional view taken along line HH of FIG. 16;

FIG. 18 is a plan view of another embodiment.

19 is a sectional view taken along line II of FIG. 18;

FIG. 20 is a schematic view showing an example in which a heating unit has a two-layer structure.

FIG. 21 is a plan view of a conventional element.

FIG. 22 is a sectional view taken along line AA of FIG. 22;

FIG. 23 is a view showing the exterior of a conventional element.

[Explanation of symbols]

30, 50, 60, 80, 90 100, 120 Infrared radiating element 31, 61, 101, 121 Element substrate 32, 62 hole 33, 63, 103, 123 p-type semiconductor layer 33a, 63a, 103a, 123a Heating section 35, 36, 65, 66, 105, 106, 125, 1
26 electrodes 38, 39, 68, 69, 108, 109, 128, 1
29 connection patterns 40, 41, 70, 71, 110, 111, 130, 1
31 Terminal 43, 75, 113, 135 Reinforced substrate 44, 76, 114, 136 Reflective film 82, 92 Depressed portion

Claims (3)

[Claims] An element substrate having a hole penetrating from one surface side to the opposite surface or a depression portion depressing from the one surface side to the opposite surface; and an opening of the hole or the depression formed on the one surface side of the element substrate. A semiconductor layer having a bridge-like heat-generating portion crossing the surface and emitting infrared rays from the heat-generating portion when energized; a pair of electrodes formed on the semiconductor layer to energize the heat-generating portion; and the element substrate A pair of terminals for power supply formed at the ends on the one surface side and connected to the pair of electrodes, respectively, and a reinforcing substrate fixed to the opposite surface of the element substrate for element reinforcement. Infrared radiating element. 2. An insulating frame formed on the one surface side of the element substrate so as to surround the heat-generating portion, and an infrared-transparent frame so as to cover an opening surface of the frame. The infrared radiating element according to claim 1, further comprising: a formed insulating cover. 3. The device according to claim 1, wherein at least a portion of one surface of the reinforcing substrate which closes the hole of the element substrate or a bottom of a depressed portion of the element substrate has a high reflectivity to infrared rays. The method according to claim 1 or 2, wherein
An infrared radiating element as described.