JP6076549B1 - Infrared temperature sensor, circuit board, and apparatus using infrared temperature sensor - Google Patents

Abstract

Provided is a surface-mount type infrared temperature sensor that can effectively specify a measurement part of a detection target and can be miniaturized. A surface-mount type infrared temperature sensor 1, which has an opening 21a on one surface side, a light guide portion 21 formed to guide infrared rays, and a shielding wall 22a on one surface side, and shields infrared rays. A main body 2 having thermal conductivity provided with a shielding portion 22 formed as described above, a substrate 3 disposed on the other surface side of the main body 2, and disposed on the substrate 3. The infrared detecting thermal element 4 disposed at a position corresponding to the infrared detecting thermal element 4 is disposed on the substrate 3 so as to be spaced apart from the infrared detecting thermal element 4 and disposed at a position corresponding to the shielding portion 22. A temperature-compensating thermal element 5, a wiring pattern 31 formed on the substrate 2 and connected to the infrared detecting thermal element 4 and the temperature-compensating thermal element 5, and connected to the wiring pattern 31; Mounting terminals formed on the end side on the substrate 3 And a 2.

Description

  The present invention relates to a surface-mounted infrared temperature sensor that detects infrared rays from a detection object and measures the temperature of the detection object, a circuit board on which the infrared temperature sensor is mounted, and a device using the infrared temperature sensor. .

  Conventionally, for example, as a temperature sensor for measuring the temperature of an object to be detected such as a heat fixing roller used in a fixing device of a copying machine, infrared light from the object to be detected is detected in a non-contact manner and the temperature of the object to be detected is measured. An infrared temperature sensor is used.

Such an infrared temperature sensor is provided with a temperature compensating thermal element in addition to the infrared detecting thermal element in order to compensate for a change in ambient temperature. Further, the infrared temperature sensor has a lead wire connected to the infrared detection thermal element and the temperature compensation thermal element and led out to the outside, and is arranged to face the detection target ( For example, see Patent Document 1).
Since the infrared temperature sensor disclosed in Patent Document 1 is not a structure suitable for surface mounting, there is a problem that it cannot meet the needs of surface mounting.
On the other hand, surface mount type infrared temperature sensors have been proposed to meet the needs of surface mounting (see Patent Document 2 and Patent Document 3).

JP 2002-156284 A JP 2011-13213 A JP 2011-102791 A

  However, in the infrared temperature sensors disclosed in Patent Document 2 and Patent Document 3, the following problems occur.

(1) Since there is no optical function (for example, an infrared light guide) for specifying the measurement part of the detection target, no optical means such as a condensing lens or a reflecting mirror is actually added. And difficult to use.

(2) The housing (case) is made of resin and is made of a material having low thermal conductivity. Therefore, due to disturbances such as ambient air, the temperature of the housing is less likely to be uniform and temperature unevenness occurs. Cheap.
(3) Since an infrared absorption film and an infrared reflection film are used facing the thermosensitive element, their functions are easily deteriorated against dirt, and the reliability is lowered.
(4) This is a configuration in which the mounting terminals are drawn out and led out from the outer side surface of the resin casing to the bottom surface side, and the configuration may be complicated.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can be used to effectively specify a measurement part of a detection target and to be able to be downsized. And it aims at providing the apparatus using an infrared temperature sensor.

The infrared temperature sensor according to claim 1 is a surface-mount type infrared temperature sensor having an opening on one surface side, a light guide portion formed to guide infrared light, and a shielding wall on one surface side. A heat-conducting main body having a shielding portion formed to shield infrared rays, a concave housing space portion formed on the other surface side of the main body, and the housing space portion A substrate disposed along the wall surface; an infrared detection thermal element disposed on the substrate and disposed at a position corresponding to the light guide; and the infrared detection thermal element on the substrate; A temperature-compensating thermosensitive element disposed at a position corresponding to the shielding portion, and a pattern formed on the substrate, and connected to the infrared detecting thermosensitive element and the temperature-compensating thermosensitive element. And the wiring pattern is electrically connected to the wiring pattern. A mounting terminal that is electrically connected and is formed by being integrally patterned continuously with the wiring pattern on the end side of the substrate , and disposed outside the accommodation space. It is characterized by comprising.

The material of the main body is not particularly limited as long as it has thermal conductivity. For example, a resin containing a metal material or a thermally conductive filler can be used. Moreover, a flexible wiring board and a rigid wiring board can be used for a board | substrate. The wiring board is not limited to a specific type.
The substrate can be disposed on the main body by pressing, welding, brazing, adhesion, adhesion, or the like. The arrangement means is not particularly limited.

A chip thermistor made of a ceramic semiconductor is preferably used as the infrared detecting thermal element and the temperature compensating thermal element, but not limited to this, a thermocouple, a resistance temperature detector, or the like can be used. Furthermore, the pattern form of the wiring pattern is not particularly limited, and can be appropriately adopted according to the design, for example, a straight line shape or a meander shape.
Further, the end side on the substrate on which the mounting terminals are formed means not only the endmost part but also includes a certain range around the endmost part.

An infrared temperature sensor according to a second aspect is the infrared temperature sensor according to the first aspect , wherein the substrate is disposed on the main body by pressing.

The infrared temperature sensor according to claim 3 is the infrared temperature sensor according to claim 1 or 2 , wherein the substrate is disposed on the main body by welding.

An infrared temperature sensor according to a fourth aspect is the infrared temperature sensor according to the first or second aspect , wherein the substrate is disposed on the main body by brazing, adhesion, or adhesion.

The infrared temperature sensor according to claim 5 is the infrared temperature sensor according to any one of claims 1 to 4, wherein the substrate is formed of a material that can be thermally welded to the main body. To do.

The infrared temperature sensor according to claim 6 is the infrared temperature sensor according to any one of claims 1 to 5 , wherein a lid member is disposed on the other side facing the substrate. To do.

The infrared temperature sensor according to claim 7 is the infrared temperature sensor according to claim 6 , wherein at least a part of the inner surface of the lid member facing the substrate is a reflective surface. .

The infrared temperature sensor according to claim 8 is the infrared temperature sensor according to any one of claims 1 to 7 , wherein the main body is made of a metal material, and a thermal oxide film is formed by thermal oxidation treatment. At least the light guide section is blackened.

The infrared temperature sensor according to claim 9 is the infrared temperature sensor according to any one of claims 1 to 8 , wherein the shielding portion is formed with a hermetically sealed space portion. And a ventilation section that allows ventilation between the outside and the outside.

The infrared temperature sensor according to claim 10 is the infrared temperature sensor according to any one of claims 1 to 9 , wherein the light guide portion and the shielding portion define a boundary between the light guide portion and the shielding portion. It is characterized by being formed in a substantially symmetrical form as a center.

The infrared temperature sensor according to claim 11 is the infrared temperature sensor according to any one of claims 1 to 10 , wherein the partition wall in the main body excluding the opening on the other surface side of the light guide portion and the shielding portion. Are continuously or partially in contact with the substrate.

The infrared temperature sensor according to claim 12 is the infrared temperature sensor according to any one of claims 1 to 11 , wherein the main body has at least the light guide portion at which the opening does not protrude from the surface. It is blackened and has a thermal conductivity of 10 W / m · K or more.

The infrared temperature sensor according to claim 13 is the infrared temperature sensor according to any one of claims 1 to 12 , wherein the wiring pattern for connecting the thermal element for infrared detection and the thermal element for temperature compensation is connected. Are arranged in parallel to each other.

The infrared temperature sensor according to claim 14 is the infrared temperature sensor according to any one of claims 1 to 13 , wherein the infrared detecting thermal element and the temperature compensating thermal element are a metal oxide or a metal nitride. A thermistor element formed of a ceramic semiconductor containing an object.

The circuit board according to claim 15 is a mounting board having a connection terminal to which the mounting terminal is connected, and the infrared temperature sensor according to any one of claims 1 to 14 mounted on the mounting board. It is characterized by comprising.
As the material of the substrate, a glass epoxy substrate or the like is generally used, but a metal substrate having good thermal conductivity such as aluminum or copper is desirable.

A circuit board according to a sixteenth aspect is the circuit board according to the fifteenth aspect, characterized in that an infrared reflecting surface is formed on at least a part of the mounting substrate facing the substrate.

  The infrared reflecting surface may be formed by using an aluminum surface when the substrate is an aluminum substrate, or by forming an infrared reflecting film such as nickel or gold plating when the substrate is a copper substrate. Alternatively, an infra-red reflecting film such as nickel or gold plating may be formed on an inlay material made of copper or iron, and the opposing surface may be formed as an infrared reflecting surface.

A device using the infrared temperature sensor according to claim 17 is provided with the infrared temperature sensor according to any one of claims 1 to 14 .

  The infrared temperature sensor can be provided and applied to various devices for detecting the temperature of, for example, a fixing device of a copying machine, a battery unit, a capacitor, an IH cooking heater, and an article in a refrigerator. The specially applied device is not limited.

  According to the present invention, a surface-mount type infrared temperature sensor capable of effectively specifying a measurement part of a detection target and capable of being downsized, a circuit board on which the infrared temperature sensor is mounted, and an apparatus using the infrared temperature sensor Can be provided.

It is a perspective view which shows the infrared temperature sensor which concerns on the 1st Embodiment of this invention. It is a top view which shows the same infrared temperature sensor. It is a rear view which shows the same infrared temperature sensor. FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a cross-sectional view taken along line BB in FIG. FIG. 3 is a cross-sectional view taken along the line CC in FIG. FIG. 7 is a cross-sectional view of the main body along the line XX in FIG. 6. FIG. 8A is a cross-sectional view corresponding to FIG. 5 in which a lid member is provided on the back side of the main body, and FIG. 8B is a perspective view showing the lid member (Modification 1). FIG. 7 is a cross-sectional view corresponding to FIG. 6, provided with a ventilation portion that allows ventilation with the outside (Modification 2). It is a top view which shows a wiring pattern (modification 3). It is a perspective view which decomposes | disassembles and shows the infrared temperature sensor which concerns on the 2nd Embodiment of this invention. It is a perspective view which decomposes | disassembles the infrared temperature sensor and sees from the back side. It is a top view which shows the same infrared temperature sensor. FIG. 7 is a cross-sectional view showing the infrared temperature sensor and corresponding to FIG. 6. FIG. 15 is a cross-sectional view of the main body along the line XX in FIG. 14. It is a top view which shows an adhesive sheet. It is sectional drawing which shows the example from which the infrared temperature sensor differs.

  Hereinafter, an infrared temperature sensor according to a first embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view showing an infrared temperature sensor, FIG. 2 is a plan view showing the infrared temperature sensor, and FIG. 3 is a rear view showing the infrared temperature sensor. 4 is a sectional view taken along line AA in FIG. 2, FIG. 5 is a sectional view taken along line BB in FIG. 2, and FIG. 6 is a sectional view taken along line CC in FIG. 7 is a cross-sectional view of the main body taken along line XX in FIG. Further, FIGS. 8 to 10 show modifications. In addition, in each figure, the same code | symbol is attached | subjected to the same or an equivalent part, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 1 to 7, the infrared temperature sensor 1 includes a main body 2, a substrate 3, an infrared detecting thermal element 4 and a temperature compensating thermal element 5 disposed on the substrate 3. A wiring pattern 31 formed on the substrate 3 and a mounting terminal 32 are provided. The infrared temperature sensor 1 is a surface mount type and is configured to be suitable for surface mount.

  The main body 2 is formed in a substantially rectangular parallelepiped shape with a metal material having thermal conductivity, for example, iron, and includes a light guide portion 21, a shielding portion 22, and an accommodation space portion 23. The main body 2 has a miniaturized size in which the length in the vertical direction and the length in the horizontal direction are 8 mm to 13 mm and the height is 2 mm to 5 mm.

  The main body 2 is entirely oxidized and blackened by heat treatment. Specifically, the main body 2 is heat-treated at a high temperature of about 400 ° C. to 1000 ° C., whereby an oxide film is formed on the surface of the main body 2 and is blackened. The thickness of the oxide film is preferably 10 μm or less, and specifically 3 μm. The emissivity is preferably 0.8 or more, and an emissivity of 0.8 to 0.95 can be obtained by the blackening treatment.

  The material forming the main body 2 is not particularly limited as long as it has a thermal conductivity of at least 10 W / m · K. For example, materials containing carbon, metal, ceramic and other fillers in resin, metal materials such as iron, nickel, chromium, cobalt, manganese, copper, titanium and molybdenum, alloys containing these metals, and black paint on metal materials The material which gave, ceramic, etc. can be used. Moreover, since the emissivity of the resin itself is high, the surface of the resin becomes black.

  The main body 2 is formed with a light guide portion 21 and a shielding portion 22. The light guide portion 21 has an opening 21 a on one surface side (front side) of the main body 2 and is formed so as to guide infrared rays. ing. The shielding part 22 has a shielding wall 22a on one side (front side) and is formed so as to shield infrared rays.

  The light guide 21 is formed as a cylindrical through-hole through which the opening 21a penetrates from the front side to the back side, and the back side is opened. The inner peripheral surface of the light guide 21 is as described above. It is oxidized to black body. The opening 21 a is formed so as not to protrude from the surface of the main body 2, is horizontally long and has a substantially rectangular shape with rounded corners, and has a longitudinal length of 3 mm to 6 mm, specifically 6 mm. It is formed, and the length dimension in the lateral direction is 1 mm to 2.5 mm, specifically 2 mm. Therefore, the dimension of the opening 21a is in the range of 1 mm to 6 mm, and the maximum dimension is set to 6 mm or less.

  Note that the shape of the opening 21a is not particularly limited. You may form in circular shape, elliptical shape, polygonal shape, etc. It can be appropriately selected depending on the form of the measurement part of the detection object. Further, when the main body 2 is not blackened by oxidation, the infrared absorption layer may be formed on the inner peripheral surface of the light guide portion 21 by performing, for example, black coating or alumite treatment as necessary. Good.

  The shielding part 22 is disposed adjacent to the light guide part 21 and is formed in a substantially symmetrical form with the boundary between the light guide part 21 and the shielding part 22 as the central axis. The shielding part 22 has a shielding wall 22a on the front side, and extends to the back side in the same shape as the light guide part 21, that is, in a substantially rectangular shape with rounded corners having the same shape as the opening part 21a. Forming. The space 22b is a concave cavity, and the back side facing the shielding wall 22a is opened.

  That is, as representatively shown in FIG. 7, in the main body 2, the cross-sectional shape of the portion of the shielding portion 22 that does not include the shielding wall 22 a has the boundary between the light guide portion 21 and the shielding portion 22 as the central axis C. It has a substantially symmetrical form. In other words, except for the opening 21a of the light guide 21 and the shielding wall 22a of the shield 22, the light guide 21 side and the shield 22 side are formed in substantially the same shape.

  As described above, the light guide unit 21 and the shielding unit 22 have a certain space region formed by the surrounding partition walls 24. Here, for convenience, the partition wall 24 at the boundary between the light guide portion 21 and the shielding portion 22 is referred to as a central wall 24a, and the other partition wall 24 is referred to as a peripheral wall 24b.

  The accommodating space 23 is formed on the back side inside the main body 2. Specifically, the accommodation space portion 23 is formed in a substantially rectangular parallelepiped concave shape, and communicates with the openings on the back side of the light guide portion 21 and the shielding portion 22.

  The board | substrate 3 is an insulating film which absorbs the infrared rays formed in the substantially rectangular shape, and is a flexible wiring board (FPC) which has flexibility. The substrate 3 is disposed on the other surface side (back surface side) of the main body 2. In detail, the board | substrate 3 is bend | folded along the inner wall of the said accommodation space part 23, and is heat-welded and arrange | positioned. In this case, the substrate 3 may be formed into a shape along the inner wall of the accommodation space 23.

  The substrate 3 is provided with an infrared detecting thermal element 4 and a temperature compensating thermal element 5 on one surface of the insulating base (the back side in FIGS. 4 to 6). Similarly, on one surface, a conductor wiring pattern 31 and a mounting terminal 32 that is electrically connected to the wiring pattern 31 and located on the end side are formed.

  For the substrate 3, a resin made of a polymer material such as polyimide, polyethylene, liquid crystal polymer, fluorine, silicon, polyester, polycarbonate, or PPS (polyphenylene sulfide) can be used. In addition, carbon black or an inorganic pigment (one or more of chrome yellow, petal, titanium white, and ultramarine) may be mixed and dispersed in these resins to use a material that can absorb infrared rays of almost all wavelengths.

  In the present embodiment, since the substrate 3 is bent along the inner wall of the housing space 23 and disposed by thermal welding, the substrate 3 is made of a material such as polyimide, polyethylene, or liquid crystal polymer that can be thermally welded. It has been.

  As shown in FIGS. 2 and 3, the wiring pattern 31 has a rectangular electrode terminal 31a on one end side, a narrow pattern extends from the electrode terminal 31a in a meander shape, and is formed at a terminal portion on the other end side. A rectangular mounting terminal 32, specifically, a land for soldering is formed. A pair of wiring patterns 31 having the same pattern is arranged so that the electrode terminals 31a face each other, and the infrared detecting thermal element 4 or the temperature compensating thermal element 5 is arranged and connected.

  Therefore, in order to connect the infrared detecting thermal element 4 and the temperature compensating thermal element 5, the two pairs of wiring patterns 31 are arranged substantially parallel to each other. The wiring pattern 31dt to which the infrared detection thermal element 4 is connected and the wiring pattern 31cp to which the temperature compensation thermal element 5 is connected are in the same pattern, and are not connected to each other. The element 4 and the temperature compensating thermal element 5 are individually connected.

  On the wiring pattern 31, a cover layer 33, which is an insulating layer made of a resin film typified by a polyimide film, resist ink, or the like, is formed. The cover layer 33 is formed so as to cover the wiring pattern 31, but the electrode terminal 31 a and the mounting terminal 32 are exposed portions that are not covered by the cover layer 33.

Further, the cover layer 33 can absorb infrared rays of almost all wavelengths by mixing and dispersing carbon black or inorganic pigment (one or more of chrome yellow, petal, titanium white, ultramarine) in polyimide film and resist ink. Materials may be used. By using an infrared absorbing material for the cover layer 33, the received light energy is increased and the sensitivity can be improved.
For the sake of explanation, the wiring pattern 31 is clearly shown in a state where it can be seen through the substrate 3 in FIG. 2 and through the cover layer 33 in FIG.

  Such a wiring pattern 31 is formed by patterning with rolled copper foil, electrolytic copper foil or the like, and the mounting terminals 32 are provided with nickel plating, gold plating or solder in order to reduce connection resistance and prevent corrosion. Plating treatment such as plating is performed.

  The infrared detecting thermal element 4 detects infrared rays from the detection target and measures the temperature of the detection target. The temperature-compensating thermal element 5 detects the ambient temperature and measures the ambient temperature. The infrared detecting thermal element 4 and the temperature compensating thermal element 5 are composed of thermal elements having at least substantially equal temperature characteristics, connected between the opposing electrode terminals 31a of the wiring pattern 31, and spaced apart from each other. Mounting is arranged.

  Specifically, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 are chip thermistors in which terminal electrodes are formed at both ends. As this thermistor, there are thermistors of the NTC type, the PTC type, the CTR type, etc. In this embodiment, for example, an NTC type thermistor is adopted.

  In particular, in the present embodiment, as the infrared detecting thermal element 4 and the temperature compensating thermal element 5, ceramic semiconductors containing metal oxides or metal nitrides of Mn, Co, Ni, and Fe, that is, Mn—Co—Ni. A thin film thermistor element formed of a Fe-based material is used. Since this ceramic semiconductor has a high B constant which is a temperature coefficient, it is possible to detect a temperature change of the substrate 3 that absorbs infrared rays with high sensitivity.

  In addition, the ceramic semiconductor desirably has a crystal structure having a cubic spinel phase as the main phase. In this case, since there is no anisotropy and no impurity layer, the electrical characteristics within the ceramic sintered body. Variation is small, and highly accurate measurement is possible when using a plurality of infrared temperature sensors. In addition, because of the stable crystal structure, the environment resistance is high. As the ceramic semiconductor, a single-phase crystal structure composed of a cubic spinel phase is most desirable.

  Further, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 are selected from thermistor elements and thin film thermistors obtained from the same wafer formed of ceramics semiconductors by resistance values within a predetermined tolerance. It is preferable that

  In this case, the relative error of the B constant is reduced between the pair of infrared detecting thermal element 4 and temperature compensating thermal element 5, and at the same time, the temperature difference between the two detecting temperatures can be detected with high accuracy. In addition, for the infrared detecting thermal element 4 and the temperature compensating thermal element 5, the B constant selection operation and the resistance value adjusting step are not required, and the productivity can be improved.

  The thermistor elements used for the infrared detecting thermal element 4 and the temperature compensating thermal element 5 may be any of a bulk thermistor, a laminated thermistor, a thick film thermistor, and a thin film thermistor, for example.

  In the infrared temperature sensor 1 configured as described above, as shown in FIG. 6, the infrared detection thermal element 4 is disposed at a position corresponding to the light guide 21, and the temperature compensation thermal element 5. Is disposed at a position corresponding to the shielding portion 22.

  Further, the central wall 24 a and the peripheral wall 24 b as the partition walls 24 in the main body 2 are arranged in contact with each other so as to be thermally coupled to the surface of the substrate 3. That is, the central wall 24 a and the peripheral wall 24 b as the partition walls 24 in the main body 2 excluding the openings on the back side of the light guide part 21 and the shielding part 22 are arranged in contact with the surface of the substrate 3. Specifically, the central wall 24 a faces and contacts the boundary portion between the infrared detecting thermal element 4 and the temperature compensating thermal element 5 on the surface of the substrate 3, and the peripheral wall 24 b is the surface of the substrate 3. The infrared detecting thermal element 4 and the temperature compensating thermal element 5 are in contact with each other so as to face each other. Further, the mounting terminals 32 formed on the end side on the substrate 3 are disposed on the back side end of the peripheral wall of the main body 2.

  The contact of the partition wall 24 on the surface of the substrate 3 may be such that the partition wall 24 continuously contacts the surface of the substrate 3 across the central wall 24a and the peripheral wall 24b. You may make it contact, for example, intermittently.

In the case of the form of partial contact, the central wall 24a and the peripheral wall 24b on one side (longitudinal direction) of the light guide part 21 and the shielding part 22 are brought into contact with each other on the surface of the substrate 3. A configuration can be adopted in which the peripheral wall 24b on the other side (short direction) of the shielding portion 22 is not in contact. In addition, by making the light guide portion 21 and the peripheral wall 24b on the other side (short direction) of the light shielding portion 22 non-contact, this non-contact portion is suitably used for forming the ventilation portion 9 described later. It becomes possible.
In the main body 2 of the present embodiment, the opening 21a does not protrude from the surface, and at least the light guide 21 is blackened.

  In the conventional infrared temperature sensor having a structure in which the opening protrudes from the surface, the material of the main body is made of aluminum, aluminum alloy, zinc alloy or the like having a thermal conductivity of 96 W / m · K or more. . This is because if there is a protrusion, a temperature difference occurs in the main body, so that a material with poor heat conduction cannot be used.

  In the case of a thermal fixing device such as a copying machine, the infrared temperature sensor is installed at a very short distance of about 5 mm with respect to the heat roller of the heat source. In such an environment, the infrared temperature sensor having a structure in which the opening protrudes has a problem that the infrared temperature sensor cannot function correctly unless it is an expensive material with good heat conduction.

  In the present embodiment, the opening 21a does not protrude from the surface and does not have a protrusion, so that the main body 2 can be used even if the thermal conductivity is 10 W / m · K or more. It is possible to use materials such as iron, stainless steel, and resin having good thermal conductivity containing filler.

  As shown mainly in FIG. 2, the wiring pattern 31dt to which the infrared detecting thermal element 4 is connected and the wiring pattern 31cp to which the temperature compensating thermal element 5 is connected are arranged substantially in parallel. The light guide portion 21 and the shielding portion 22 are arranged in parallel corresponding to the wiring patterns 31dt and 31cp. With such an arrangement, the distance between the infrared detecting thermal element 4 and the temperature compensating thermal element 5 is reduced, so that temperature compensation is more reliable and accurate temperature detection is possible.

  As shown in FIGS. 4 to 6, such an infrared temperature sensor 1 is mounted on a mounting board as a circuit board 10. A predetermined wiring pattern is formed on the surface side of the mounting substrate, and the connection terminal 11 to which the mounting terminal 32 of the infrared temperature sensor 1 is connected is formed. Therefore, the mounting terminal 32 of the infrared temperature sensor 1 is electrically connected to the connection terminal 11 of the mounting substrate by soldering or the like. Note that this connection means is not limited to a particular one. For example, a conductive adhesive or the like may be used, and any means may be used as long as electrical connection is possible.

In addition, an infrared reflecting portion 12 is provided on the surface side of the mounting substrate and facing the substrate 3. The infrared reflecting portion 12 is formed, for example, as a reflecting surface by mirroring a metal plate, and has a high reflectance of 80% or more, preferably 85% or more. Therefore, the reflection part 12 has a low emissivity, can suppress the thermal influence on the thermal element 4 for infrared detection and the thermal element 5 for temperature compensation, and can improve the sensitivity.
In this case, a predetermined effect can be exhibited if at least a part of the surface facing the substrate is an infrared reflecting surface.

  Next, the operation of the infrared temperature sensor 1 will be described. Infrared radiation radiated from the surface of the detection object enters through the opening 21 a in the light guide 21 of the infrared temperature sensor 1, is guided to the light guide 21, passes through the light guide 21, and reaches the substrate 3. Since the opening 21a has a function of limiting the visual field, it is possible to effectively specify the measurement part of the detection target and improve the detection accuracy. The infrared rays that have reached the substrate 3 are absorbed by the substrate 3 and converted into thermal energy.

  The converted thermal energy is transmitted to the infrared detecting thermal element 4 directly below through the substrate 3 and raises the temperature of the infrared detecting thermal element 4. The infrared detection thermal element 4 and the temperature compensation thermal element 5 are ceramic semiconductors having at least substantially equal temperature characteristics, and the resistance value of the infrared detection thermal element 4 changes due to infrared rays from the detection target.

  At the same time, infrared rays are shielded by the shielding wall 22a of the shielding part 22, but the temperature of the main body 2 rises due to the radiant heat from the object to be detected and the ambient atmosphere temperature. The resistance value changes corresponding to the rise.

In this case, since the main body 2 is formed of a material having thermal conductivity such as metal, the temperature change of the infrared temperature sensor 1 can be made uniform as a whole following the temperature change of the surroundings. The light guide 21 and the shielding part 22 are substantially symmetrical with the boundary between the light guiding part 23 and the shielding part 22 as the central axis C, and are formed in substantially the same shape. Furthermore, the wiring pattern 31dt to which the infrared detecting thermal element 4 is connected and the wiring pattern 31cp to which the temperature compensating thermal element 5 is connected are formed in the same pattern.
Furthermore, the central wall 24 a and the peripheral wall 24 b in the main body 2 are in contact with the surface of the substrate 3.

  For this reason, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 change in the same way with respect to the surrounding temperature change, have good followability and can suppress the influence on thermal disturbance, It becomes possible to accurately detect a temperature change due to infrared rays from the object.

  In addition, the wiring pattern 31dt and the wiring pattern 31cp respectively connect the infrared detecting thermal element 4 and the temperature compensating thermal element 5 individually. Therefore, the mutual thermal influence between the wiring pattern 31dt and the wiring pattern 31cp can be reduced, and the sensitivity can be improved.

  Further, since the central wall 24a of the main body 2 is in contact with the boundary portion between the infrared detecting thermal element 4 and the temperature compensating thermal element 5 at least on the surface of the substrate 3, the heat of the substrate 3 is transferred to the central wall. Conducted to 24a. For this reason, the temperature gradient in the boundary portion can be suppressed, the heat of the substrate 3 on the infrared detecting thermal element 4 side is reduced from being conducted to the substrate 3 on the temperature compensating thermal element 5 side, and mutual interference is prevented. Can be reduced. Therefore, it is possible to obtain a high temperature difference between the infrared detecting thermal element 4 and the temperature compensating thermal element 5, and an improvement in sensitivity can be realized.

  Further, since the thermal and optical interference between the infrared detecting thermal element 4 and the temperature compensating thermal element 5 is suppressed, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 are arranged close to each other. Can contribute to the overall size reduction.

  As described above, according to the present embodiment, it is possible to provide a surface-mount type infrared temperature sensor that can effectively specify a measurement part of a detection target and can be downsized, and a circuit board on which the infrared temperature sensor is mounted. be able to.

  Next, a modification of the present embodiment will be described with reference to FIGS. FIG. 8A is a cross-sectional view corresponding to FIG. 5 in which a lid member is provided on the back side of the main body, and FIG. 8B is a perspective view showing the lid member (Modification 1). FIG. 9 is a cross-sectional view corresponding to FIG. 6 in which a ventilation portion for reducing deformation of the substrate is provided (Modification 2). FIG. 10 is a plan view showing a wiring pattern (Modification 3).

  (Modification 1) As shown in FIG. 8, the lid member 8 has a substantially rectangular parallelepiped box shape and is made of a metal material such as aluminum. The lid member 8 is disposed on the back side so as to face the substrate 3. At least a part of the inner surface of the lid member 8 facing the substrate 3 is a reflective surface, and is, for example, mirror-finished to have a high reflectance, which is 80% or more, preferably 85% or more. Yes. The lid member 8 is fitted and attached to the accommodation space 23. For this reason, the lid member 8 also has a function of fixing the substrate 3 to the accommodation space 23.

  Thus, since the inner surface of the lid member 8 is a reflective surface, the emissivity is low, the thermal influence on the infrared detecting thermal element 4 and the temperature compensating thermal element 5 can be suppressed, and the sensitivity is improved. Can be achieved.

  As described above, the light guide portion 21 side and the shielding portion 22 side are formed in substantially the same shape, but the lid member 8 is also formed to have substantially the same shape with respect to the central axis C. ing.

(Modification 2) As shown in FIG. 9, the space 22 b in the shield 2 is a hermetically sealed space with the back side opening being closed by the substrate 3. In this example, the ventilation part 9 which permits the air permeability of the space part 22b and the exterior is provided. Specifically, the ventilation part 9 is a through hole and is not particularly limited, but is preferably formed to have a diameter of about 0.1 mm to 0.5 mm. Further, for example, when a ventilation gap is formed between the substrate 3 and the main body 2 as the ventilation portion, this gap may be a gap through which air passes, and if there is a gap of 1 μm or more, the air is sufficiently circulated. be able to. The important thing is not to have a sealed structure.
Therefore, the same effect can be obtained even if a hole of about φ0.1 mm to φ0.5 mm is formed in the portion of the substrate 3 corresponding to the space 22b.
Further, it is preferable to form a through hole 9 ′ similar to the ventilation part 9 on the light guide part 21 side, and to form the light guide part 21 side and the shielding part 22 side in substantially the same shape which is substantially symmetrical.

  In the infrared temperature sensor, when the ambient temperature of the infrared temperature sensor increases, the air in the sealed space portion expands to increase the internal pressure, causing a problem that the substrate swells and deforms. Further, when the air in the space portion is excessively expanded, there may be a problem that the wiring pattern wired on the substrate is cut due to deformation of the substrate. Furthermore, the deformation of the substrate causes a change in the amount of incident infrared rays and the amount of heat released from the substrate, causing a problem that the output of the infrared temperature sensor varies.

  In this example, even in a temperature environment where the internal pressure of the space portion 22b increases, the ventilation portion 9 ensures air permeability from the outside, suppresses the increase in internal pressure, and reduces deformation of the substrate 3. Is possible. Therefore, it is possible to provide the infrared temperature sensor 1 that can reduce deformation of the substrate 3, enable high accuracy, and ensure reliability. In addition, the ventilation | gas_flowing part 9 may be not only a through-hole but a groove shape. The ventilation part 9 should just be formed so that a sealed space part and the exterior may communicate, and a formation position, a shape, a number, etc. are not specifically limited.

  (Modification 3) As shown in FIG. 10, a wiring pattern 31dt and a wiring pattern 31cp are individually connected to the infrared detecting thermal element 4 and the temperature compensating thermal element 5, respectively. The wiring pattern 31 has a rectangular electrode terminal 31a at one end, and a meandering shape is formed around the electrode terminal 31a so that a narrow pattern surrounds the infrared detecting thermal element 4 (temperature compensating thermal element 5). Further, a narrow pattern is formed so as to extend in a meander shape toward the rectangular mounting terminal 32.

  According to such a configuration, since the heat conduction path of the wiring pattern 31 becomes long, it is difficult for heat to escape, the temperature of the infrared detecting thermal element 4 and the temperature compensating thermal element 5 is maintained, and the output is increased. In addition, it is possible to improve sensitivity.

  In the above description, the case where the substrate 3 is attached by being thermally welded to the inner wall of the accommodation space 23 on the main body 2 side has been described. However, the substrate 3 is disposed on the main body 2 by pressing. May be. For example, the main body 2 can be pressed against the substrate 3 so as to be plastically deformed and bonded to the substrate 3 side. Moreover, you may make it arrange | position by adhesion | attachment or adhesion. In this case, it is desirable that an adhesive layer or an adhesive layer, for example, an adhesive sheet or an adhesive sheet is provided on the inner wall of the accommodation space 23 and the substrate 3 is attached with the sheet interposed therebetween. Furthermore, you may make it arrange | position by brazing.

  Moreover, although the board | substrate 3 demonstrated the case where a flexible wiring board was used, you may make it use a rigid wiring board. The wiring board is not limited to a specific type.

  Furthermore, the mounting substrate as the circuit substrate 10 may use a metal substrate such as aluminum or copper having an insulating layer on the surface. In this case, since the mounting substrate has high thermal conductivity, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 have better followability to ambient temperature changes and suppress the influence on thermal disturbance. be able to.

  In addition, in the mounting substrate, in correspondence with the range where the infrared temperature sensor 1 is mounted, at least a part of the surface of the range may be formed as an infrared reflecting surface having a high reflectance, for example, a mirror surface portion. . In this case, the lid member 8 can be omitted, and the mirror surface portion can perform the same function as the reflecting surface of the lid member 8, and the sensitivity can be improved.

  Next, an infrared temperature sensor according to a second embodiment of the present invention will be described with reference to FIGS. 11 is an exploded perspective view of the infrared temperature sensor, FIG. 12 is an exploded perspective view of the infrared temperature sensor as viewed from the back side, and FIG. 13 is a plan view of the infrared temperature sensor. FIG. 14 shows an infrared temperature sensor, which is a cross-sectional view corresponding to FIG. 6, and FIG. 15 is a cross-sectional view of the main body taken along line XX in FIG. FIG. 16 is a plan view showing the adhesive sheet. In addition, the same code | symbol is attached | subjected to the part which is the same as that of 1st Embodiment, or an equivalent part, and the overlapping description is abbreviate | omitted.

  In the present embodiment, as in the first embodiment, the main body 2 is formed in a substantially rectangular parallelepiped shape from a metal material having thermal conductivity. And the whole main body 2 is oxidized and blackened by heat processing, and has the light guide part 21 and the shielding part 22, but the accommodation space part is not formed. Therefore, the other surface side (rear surface side) of the main body 2 is a planar planar portion in which the light guide portion 21 and the shielding portion 22 are opened.

  The substrate 3 is a flat rigid wiring substrate formed in a rectangular shape having a thickness dimension of 0.05 mm to 0.2 mm. The substrate 3 has substantially the same outer shape as that of the other surface side (back side) of the main body 2, and is disposed along a planar portion on the back side of the main body 2. Specifically, as in the first embodiment, the substrate 3 is attached to the back side of the main body 2 by means such as heat welding, brazing, adhesion, or adhesion.

  As shown in FIG. 12, in the present embodiment, the substrate 3 is disposed on the back side of the main body 2 by attaching the adhesive sheet 34 to the back side of the main body 2 and attaching the substrate 3 to the adhesive sheet 34. Is called. That is, the substrate 3 is attached with the adhesive sheet 34 interposed between the back side of the main body 2 and the substrate 3. Specifically, as shown in FIG. 16, the adhesive sheet 34 has substantially the same outer shape as the back side of the main body 2, and the center part corresponds to the back side opening of the light guide part 21 and the shielding part 22. It is cut out. Note that an adhesive sheet may be used instead of the adhesive sheet.

  The substrate 3 is provided with an infrared detecting thermal element 4 and a temperature compensating thermal element 5 on one surface of an insulating base material. Similarly, on one surface, a conductor wiring pattern 31 and a mounting terminal 32 which is electrically connected to the wiring pattern 31 and located on the end side are formed.

  As representatively shown in FIGS. 11 to 14, the main body 2 is not formed with an accommodating space. For this reason, the back side of the main body 2 has a planar shape, and the light guide portion 21 and the shielding portion 22 are opened in the planar portion (see FIG. 12). Accordingly, the flat substrate 3 is disposed on the planar portion on the back side of the main body 2.

  The substrate 3 is a flat rigid wiring substrate. For example, an insulating base material made of glass epoxy resin, polyphenylene ether (PPE resin), silicone resin material, etc., and a conductor formed on the surface of the insulating base material Wiring pattern 31. A resist layer 33 that is an insulating layer is stacked on the wiring pattern 31. Further, the resist layer 33 is not laminated at both ends of the wiring pattern 31, that is, exposed electrode terminals 31 a and mounting terminals 32 that are not covered with the resist layer 33 are formed. In the electrode terminal 31a, only a part to which the terminal electrode of the infrared detecting thermal element 4 or the temperature compensating thermal element 5 is connected is an exposed part not covered with the resist layer 33.

  The wiring pattern 31 has a substantially rectangular electrode terminal 31a on one end side, a narrow pattern extends linearly from the electrode terminal 31a, and a rectangular mounting terminal 32 is provided at the terminal end on the other end side. Formed and configured. A pair of wiring patterns 31 of the same pattern are arranged so that the electrode terminals 31a face each other, and the infrared detecting thermal element 4 or the temperature compensating thermal element 5 is arranged and connected.

  Therefore, in order to connect the infrared detecting thermal element 4 and the temperature compensating thermal element 5, the two pairs of wiring patterns 31 are arranged substantially in parallel. The wiring pattern 31dt to which the infrared detection thermal element 4 is connected and the wiring pattern 31cp to which the temperature compensation thermal element 5 is connected are in the same pattern, and are not connected to each other. The element 4 and the temperature compensating thermal element 5 are individually connected.

  For the sake of explanation, the wiring pattern 31 is shown clearly in a state where it can be seen through the insulating base material in FIG. 11 and through the resist layer 33 in FIG.

  As shown in FIG. 14, the infrared temperature sensor 1 is mounted on a mounting board as the circuit board 10. This mounting substrate is a metal substrate, and is formed, for example, by laminating an insulating base material 14 made of a glass epoxy resin, a glass composite material or the like on a metal base material 13 made of an aluminum material. A hole is formed in a portion of the insulating base material 14 facing the substrate 3, and a cavity 15 is formed between the hole and the metal base material 13 by the hole. Furthermore, the surface of the metal base 13 facing the substrate 3 is formed as a reflective surface 16. As described above, the reflecting surface 16 has a high reflectance, and has a reflectance of 80% or more, preferably 85% or more. Thus, for example, a copper inlay substrate having a cavity structure is used as the mounting substrate, although not shown. Note that this does not prevent the above-described lid member 8 from being disposed in the cavity 15.

  Furthermore, as described in (Modification 2) in the first embodiment described above, the space portion 22b in the shielding portion 2 is a hermetically sealed space portion with the opening on the back side closed by the substrate 3. However, it is desirable to provide the ventilation part 9 which allows the air permeability between the space part 22b and the outside. Specifically, a gap is formed as a ventilation portion 9 between the central wall 24 a of the partition wall 24 at the boundary portion between the light guide portion 21 and the shielding portion 22 and the substrate 3. If this gap is 1 μm or more, sufficient air can be circulated.

  Alternatively, as shown in FIG. 17, the infrared temperature sensor 1 may be mounted on a shielded substrate 3. In the infrared temperature sensor 1 of this example, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 are arranged on the front side of the substrate 3, and the infrared detecting thermal element 4 is the light guide 21. The temperature compensating thermal element 5 is disposed at a position corresponding to the shielding portion 22.

  The substrate 3 is a flat rigid wiring substrate, and is electrically connected to the insulating base material, the conductor wiring pattern 31 formed on the surface of the insulating base material, and the end portion of the wiring pattern 31. And a mounting terminal 32 located on the side. Further, a resist layer 33 such as a resist ink which is an insulating layer is laminated on the wiring pattern 31. The mounting terminal 32 is an exposed portion that is not covered with the resist layer 33.

  A shield ring 17 is provided on the back side of the substrate 3, and the outer periphery of the shield ring 17 including the substrate 3 is plated to form a plated portion 18. By this plated portion 18, the infrared detecting thermal element 4 and the temperature compensating thermal element 5 are shielded.

Further, the plating portion 18 is connected to the mounting terminal 32 and led out to the back side of the shield ring 17 so that the mounting terminal 32 can be electrically connected to a connection terminal of a circuit board (not shown). Has been. The shield property can be further improved by electrically connecting the shield ring 17 and the conductive main body 2.
According to such a configuration, it is possible to provide the infrared temperature sensor 1 that can suppress the influence of noise and can perform a function strong against noise.

  As described above, according to this embodiment, the same operation as that of the first embodiment can be realized, and a surface-mount type infrared ray capable of effectively specifying the measurement part of the detection target and being miniaturized. The temperature sensor 1 and the circuit board 10 on which the infrared temperature sensor 1 is mounted can be provided. Moreover, when the structure of the main body 2 is simplified and the infrared temperature sensor 1 is mounted on the circuit board 10, there is an effect that the protruding height dimension of the infrared sensor 1 can be reduced.

  In the above description, a case where a rigid wiring board is used as the board 3 has been described. However, a flexible wiring board may be used. The wiring board is not limited to a specific type.

  The infrared temperature sensor 1 in each of the embodiments described above can be provided and applied to various apparatuses for detecting the temperature of a fixing device of a copying machine, a battery unit, a capacitor, an IH cooking heater, an article in a refrigerator. The specially applied device is not limited.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications can be made without departing from the spirit of the invention. Moreover, each said embodiment is shown as an example and is not intending limiting the range of invention.

For example, a chip thermistor formed of a ceramic semiconductor is preferably used as the infrared detection thermal element and the temperature compensation thermal element, but not limited thereto, a thermocouple, a resistance temperature detector, or the like can be used.
Further, the pattern form of the wiring pattern is not particularly limited, and can be appropriately adopted according to the design, such as a straight line shape or a meander shape.

DESCRIPTION OF SYMBOLS 1 ... Infrared temperature sensor 2 ... Main body 3 ... Board | substrate 4 ... Infrared detection thermal element 5 ... Temperature compensation thermal element 8 ... Cover member 9 ... Ventilation part 10 ... -Circuit board 11 ... Connection terminal 12 ... Infrared reflecting part 15 ... Cavity 21 ... Light guide part 21a ... Opening part 22 ... Shielding part 22a ... Shielding wall 22b ... Space part 23 ... accommodating space part 24 ... partition wall 31 ... wiring pattern 32 ... mounting terminal 33 ... insulating layer (cover layer, resist layer)
34 ... Adhesive sheet

Claims (17)

A surface mount infrared temperature sensor,
Thermal conductivity provided with a light guide part that has an opening on one side and is configured to guide infrared rays, and a shielding part that has a shielding wall on one side and is configured to shield infrared rays. A body having;
A concave accommodation space formed on the other surface of the main body;
A substrate disposed along a wall surface constituting the housing space;
A thermal sensing element for infrared detection disposed on the substrate and disposed at a position corresponding to the light guide;
A temperature-compensating thermosensitive element disposed on the substrate and spaced apart from the infrared detecting thermosensitive element and disposed at a position corresponding to the shielding portion;
A wiring pattern formed by patterning on the substrate and connected to the infrared detecting thermal element and the temperature compensating thermal element;
For mounting that is electrically connected to the wiring pattern, is formed by being continuously patterned integrally with the wiring pattern on the end side of the substrate , and is disposed outside the housing space . A terminal,
An infrared temperature sensor comprising: The infrared temperature sensor according to claim 1 , wherein the substrate is disposed on the main body by pressing. The infrared temperature sensor according to claim 1 , wherein the substrate is disposed on the main body by welding. The infrared temperature sensor according to claim 1 , wherein the substrate is disposed on the main body by brazing, bonding, or sticking. The infrared temperature sensor according to any one of claims 1 to 4 , wherein the substrate is formed of a material that can be thermally welded to the main body. The infrared temperature sensor according to any one of claims 1 to 5 , wherein a lid member is disposed on the other side facing the substrate. The infrared temperature sensor according to claim 6 , wherein at least a part of the inner surface of the lid member facing the substrate is an infrared reflecting surface. The body is made of a metallic material, according to any one of claims 1 to 7 at least said light guide portion is thermally oxidized film is formed, characterized in that it is a black body by thermal oxidation Infrared temperature sensor. The shield portion is closed spatial portion is formed, any of claims 1 to 8, characterized in that vent to allow breathability of the space portion and the outside is provided An infrared temperature sensor according to claim 1. The said light guide part and a shielding part are formed in the substantially symmetrical form centering | focusing on the boundary of a light guide part and a shielding part, The Claim 1 thru | or 9 characterized by the above-mentioned. Infrared temperature sensor. Partition wall of the main body excluding the other surface side opening of the light guide portion and the shielding portion is one of claims 1 to 10, characterized in that it continuously or in partial contact on a substrate The infrared temperature sensor according to 1. The body, together with the opening does not protrude from the surface, and at least the light guide portion is black body of, and claims 1 to, characterized in that it comprises a thermal conductivity of at least 10 W / m · K Item 12. The infrared temperature sensor according to any one of Items 11 . The wiring pattern for connecting the infrared detecting heat sensitive element and the temperature compensating thermal sensitive element, any one of claims 1 to 12, characterized in that it is arranged are arranged substantially parallel to each other An infrared temperature sensor according to claim 1. The infrared detecting heat sensitive element and the temperature compensating thermal sensitive element, any one of claims 1 to 13, characterized in that a thermistor element formed of a ceramic semiconductor containing metal oxide or metal nitride An infrared temperature sensor according to claim 1. A mounting substrate having a connection terminal to which the mounting terminal is connected;
The infrared temperature sensor according to any one of claims 1 to 14 , which is mounted on the mounting board,
A circuit board comprising: The circuit board according to claim 15 , wherein an infrared reflecting surface is formed on at least a part of the mounting substrate facing the substrate. An apparatus using an infrared temperature sensor, comprising the infrared temperature sensor according to any one of claims 1 to 14 .

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