Infrared temperature sensor and method for manufacturing infrared temperature sensor

Abstract

To improve accuracy of temperature measurement.SOLUTION: An infrared temperature sensor 100 includes: a mounting substrate 20 having an annular land 10; a metal plate 30 mounted on the mounting substrate 20; a sensor chip 40 mounted on the metal plate 30 for detecting infrared radiation; a circuit unit 50 mounted on the metal plate 30 for amplifying a detection signal output from the sensor chip 40; and a metal cap 60 covering the sensor chip 40 and the circuit unit 50, wherein the solder 110 is disposed between the annular land 10 and the metal plate 30, and the solder 110 is formed along the annular land 10 over an entire circumference.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an infrared temperature sensor and a method for manufacturing an infrared temperature sensor. [Background technology]

[0002] For example, a radiation sensor for non-contact temperature measurement or infrared spectroscopy is known in which at least a part of the radiation-absorbing absorber element is not in contact with a planar rectangular annular support, and the support is mounted on a flat carrier substrate (see, for example, Patent Document 1).

[0003] The radiation sensor described in Patent Document 1 comprises a support having a recess and a detector element arranged above the recess. The absorber element absorbs radiation and is heated as a result. A metal layer is provided on the carrier substrate. The bottom of the recess, located below the absorber element, is coated with a metal material that reflects the radiation to be detected. The metal layer beyond the detector chip is provided with a radiation absorbing layer that absorbs the radiation to be detected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4685019 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a demand for improved temperature measurement accuracy in temperature sensors. An object of the present disclosure is to provide an infrared temperature sensor with improved temperature measurement accuracy and a method for manufacturing an infrared temperature sensor. [Means for solving the problem]

[0006] The infrared temperature sensor according to the present disclosure comprises a mounting substrate having an annular land, a metal plate mounted on the mounting substrate, a sensor chip mounted on the metal plate for detecting infrared rays, a circuit unit mounted on the metal plate for amplifying the detection signal output from the sensor chip, and a metal cap covering the sensor chip and the circuit unit, and a conductive bonding agent is disposed between the annular land and the metal plate, and the conductive bonding agent is formed around the entire circumference of the annular land. [Effects of the Invention]

[0007] The present disclosure can provide an infrared temperature sensor and a method for manufacturing an infrared temperature sensor with improved temperature measurement accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an exploded perspective view illustrating an infrared temperature sensor according to an embodiment; [Figure 2] 1 is a perspective view illustrating an infrared temperature sensor according to an embodiment; [Figure 3] FIG. 2 is a plan view illustrating a mounting substrate and an annular land; [Figure 4] FIG. 10 is a plan view illustrating an infrared temperature sensor with the metal cap removed, showing the arrangement of solder. [Figure 5] 10 is a perspective view illustrating a circuit element mounted on a second surface of a mounting board. FIG. [Figure 6] FIG. 10 is a plan view illustrating an annular land according to a first modified example. [Figure 7] FIG. 10 is a plan view illustrating an annular land according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] The sensor device according to the embodiment will be described below with reference to the accompanying drawings. In this specification and the drawings, substantially identical components may be designated by the same reference numerals to avoid redundant description. The terms "upper" and "lower" may also be used in this specification. These refer to the "upper" and "lower" states shown in FIGS. 1 and 2, for example. In the Z-axis direction, the direction from the mounting substrate 20 toward the metal cap is considered "upper," and the opposite direction is considered "lower." The actual arrangement of the infrared temperature sensor 100 is not limited to this.

[0010] [Infrared temperature sensor 100 according to the embodiment] FIG. 1 is an exploded perspective view illustrating an infrared temperature sensor 100 according to an embodiment. FIG. 2 is a perspective view illustrating the infrared temperature sensor 100 according to an embodiment. FIG. 3 is a plan view illustrating a mounting substrate 20 and annular lands 10. FIG. 4 is a plan view illustrating the infrared temperature sensor 100 with the metal cap 60 removed, showing the arrangement of the solder 110. FIG. 5 is a plan view illustrating the infrared temperature sensor 100 with the metal cap 60 removed. FIG. 6 is a perspective view illustrating a circuit element 25 mounted on the second surface 22 of the mounting substrate 20. Note that in each figure, the X-axis, Y-axis, and Z-axis directions are shown, which are orthogonal to one another. The X-axis, Y-axis, and Z-axis directions do not have to be orthogonal. The X-axis, Y-axis, and Z-axis directions may be any directions.

[0011] As shown in FIGS. 1 and 2, the infrared temperature sensor 100 includes a mounting substrate 20, a metal plate 30, a sensor chip 40, a circuit section 50, and a metal cap 60. The sensor chip 40 is, for example, a thermopile-type infrared temperature sensor using MEMS (Micro Electro Mechanical Systems) technology. The infrared temperature sensor 100 can measure the surface temperature of an object to be measured without contact by capturing infrared rays emitted by the object. The infrared temperature sensor 100 may be installed in, for example, a refrigerator, a kitchen appliance, an air conditioner, or a hair dryer. The use of the infrared temperature sensor 100 is not limited, and it may be used in home appliances, beauty devices, or other devices. The object to be measured by the infrared temperature sensor 100 is not particularly limited.

[0012] [Mounting board 20] The mounting substrate 20 has a first surface 21 and a second surface 22 that face each other in the Z-axis direction. The Z-axis direction is an example of the thickness direction of the mounting substrate 20. As shown in FIGS. 1 and 3 , an annular land 10 is formed on the first surface 21 of the mounting substrate 20. This will be described in detail later. Furthermore, for example, a wiring pattern may be formed on the first surface 21 and the second surface 22 of the mounting substrate 20. Furthermore, the wiring pattern formed on the first surface 21 of the mounting substrate 20 and the wiring pattern formed on the second surface 22 are electrically connected. Via contacts that penetrate the mounting substrate 20 in the Z-axis direction may be formed to connect the wiring formed on the first surface 21 and the wiring formed on the second surface 22.

[0013] [Metal plate 30] As shown in FIGS. 1, 2, 5, and 6, a metal plate 30 is mounted on the first surface 21 of the mounting substrate 20. The metal plate 30 may be made of, for example, iron, copper, or aluminum. The thickness direction of the metal plate 30 is along the Z-axis direction. The metal plate 30 is bonded to the first surface 21 of the mounting substrate 20. As described below, the metal plate 30 is soldered to an annular land 10. The metal plate 30 has, for example, a substantially rectangular shape when viewed in the thickness direction. The shape of the metal plate 30 is not particularly limited and may be rectangular or circular. The metal plate 30 has a function of improving the thermal uniformity of the internal structure of the infrared temperature sensor 100, such as the sensor chip 40. "Thermal uniformity" may mean making the temperature uniform or preventing temperature unevenness. The metal plate 30 may also have a cross shape when viewed in the Z-axis direction. Claws 31 are arranged in narrowed portions of the cross shape of the metal plate 30. The claws 31 extend in the Z-axis direction from the first surface 21. The multiple claws 31 protrude to the opposite side from the mounting board 20 in the Z-axis direction.

[0014] [Sensor chip 40] The sensor chip 40 is mounted on the upper surface of the metal plate 30. The sensor chip 40 includes an infrared sensor element capable of receiving infrared rays. The sensor chip 40 generates an electromotive force according to the intensity of the received infrared rays. The intensity of the infrared rays depends on the difference between the temperature of the object to be measured and the temperature of the infrared sensor element.

[0015] The infrared sensor element may be a single-element sensor having one active region, or a multi-element sensor having two or more active regions. The operating principle of the infrared sensor element is not particularly limited. The infrared sensor element may be a thermopile type or a bolometer type. The infrared sensor element may be a thermal type infrared sensor or a quantum type infrared sensor.

[0016] [Circuit section 50] The circuit unit 50 is mounted on the upper surface of the metal plate 30. The circuit unit 50 includes, for example, a signal processing IC (Integrated Circuit). The circuit unit 50 is electrically connected to the sensor chip 40. The circuit unit 50 is connected to the sensor chip 40 via a first wire 91. The circuit unit 50 may include an amplifier that amplifies the electromotive force generated in the sensor chip 40. The circuit unit 50 can amplify the output signal output from the sensor chip 40.

[0017] The circuit section 50 may have a function of amplifying and then AD (analog-to-digital) converting the output signal output from the sensor chip 40. The circuit section 50 may individually adjust the output level of the amplified signal.

[0018] The circuit unit 50 can perform temperature correction according to the temperature of the sensor chip 40 itself and output a signal to the outside of the circuit unit 50. The circuit unit 50 may be, for example, an ASIC (Application Specific Integrated Circuit). The circuit unit 50 may have a function of detecting the temperature of the metal plate 30.

[0019] The circuit section 50 has an outer shape that is, for example, a rectangle when viewed in the thickness direction of the metal plate 30. The circuit section 50 and the sensor chip 40 may be disposed adjacent to each other in the X-axis direction, for example.

[0020] [Metal Cap 60] 1 and 2, the metal cap 60 is disposed so as to cover most of the upper surface of the metal plate 30. The metal cap 60 covers the sensor chip 40 and the circuit section 50 mounted on the metal plate 30. In FIGS. 1 and 2, the metal cap 60 is shown cut along the Z-axis direction. The metal cap 60 is, for example, cup-shaped, and the opening of the metal cap 60 faces downward. The metal cap 60 forms a recess that is recessed upward.

[0021] The metal cap 60 is formed, for example, to have a circular shape when viewed in the Z-axis direction. The metal cap 60 includes, for example, a cylindrical portion 61, a top portion 62, a lens 63, and a flange portion 64. The center line of the cylindrical portion 61 is along the Z-axis direction. The top portion 62 and the lens 63 are formed to cover the end of the cylindrical portion 61 opposite to the metal plate 30. The lens 63 is held by the top portion 62.

[0022] The lens 63 may be a condensing lens that condenses infrared light emitted from the object to be measured. The lens 63 is disposed away from the sensor chip 40 in the Z-axis direction. The infrared light that passes through the lens 63 is received by the sensor chip 40. The lens 63 is an example of a transmitting section that transmits infrared light. The transmitting section is not limited to a lens, and may be a filter or other transmitting section. The transmitting section includes a material that transmits infrared light, such as germanium (Ge), silicon (Si), sapphire (Al2O3), polyethylene, or chalcogenide glass.

[0023] The flange portion 64 is formed at the end of the cylindrical portion 61 closer to the metal plate 30. The flange portion 64 protrudes outward from the cylindrical portion 61 in the radial direction of the cylindrical portion 61. The thickness direction of the flange portion 64 is along the Z-axis direction. The flange portion 64 is formed around the entire circumferential direction of the cylindrical portion 61. The flange portion 64 is joined to the upper surface of the metal plate 30. The flange portion 64 can be fixed by the claws 31 of the metal plate 30. The space surrounded by the metal plate 30 and the metal cap 60 is sealed. The sensor chip 40 and the circuit unit 50 are arranged in this sealed space. The metal cap 60 may be adhered to the metal plate 30 using, for example, a thermally conductive adhesive.

[0024] [Ring Land 10] As shown in FIGS. 1 and 3, the annular land 10 is formed on the first surface 21 of the mounting substrate 20. The annular land 10 has a continuous annular shape when viewed in the Z-axis direction. The annular land 10 is formed so as to surround a predetermined area. The annular land 10 has a predetermined width. The annular land 10 may be formed at a position corresponding to the outer shape of the metal plate 30 when viewed in the Z-axis direction. The annular land 10 is a land pattern for soldering to join the metal plate 30.

[0025] The annular land 10 may be formed to form, for example, an octagonal frame, as shown in Fig. 3. The annular land 10 has a pair of sides 11x that face each other in the Y-axis direction and extend in the X-axis direction, a pair of sides 11y that face each other in the X-axis direction and extend in the Y-axis direction, and multiple sides 11u that connect the sides 11x and 11y. The multiple sides 11u are arranged so as to be inclined with respect to the X-axis direction and the Y-axis direction. The sides 11u connect the longitudinal end of the side 11x to the longitudinal end of the side 11y.

[0026] [Other Lands] 1 and 3, on the first surface 21 of the mounting substrate 20, no lands are formed in the region 23 surrounded by the annular lands 10. The region 23 surrounded by the annular lands 10 is an example of the region inside the annular lands 10.

[0027] [Arrangement of sensor chip 40] As shown in Figures 3 to 5, the sensor chip 40 is mounted at the center (center) C of the metal plate 30. In Figure 3, the sensor chip 40 is shown by a two-dot chain line. In Figures 3 to 5, the center C of the metal plate 30 is shown. The center C of the metal plate 30 is the center position of the outline of the metal plate 30 when viewed in the thickness direction of the metal plate 30. The sensor chip 40 is disposed at a position overlapping the center C when viewed in the thickness direction of the metal plate 30.

[0028] [Circular land 10 shape] The annular land 10 may have a shape symmetrical with respect to the center C of the metal plate 30, for example, a shape that is line-symmetrical. The center of the annular land 10 may be located at the same position as the center C of the metal plate 30 when viewed in the Z-axis direction. The "same position" may also mean "approximately the same position." FIG. 3 illustrates an imaginary line CLx that passes through the center C and extends in the X-axis direction, and an imaginary line CLy that passes through the center C and extends in the Y-axis direction.

[0029] The annular land 10 is formed to be line-symmetrical with respect to an imaginary straight line CLx when viewed in the Z-axis direction. The annular land 10 is formed to be line-symmetrical with respect to an imaginary straight line CLy when viewed in the Z-axis direction. The annular land 10 may have a shape that is point-symmetrical with respect to a center C, for example. The line-symmetrical shape may be an octagon, a rectangle, a circle, or any other shape.

[0030] [70 additional lands] A plurality of additional lands 70 are formed on the first surface 21 of the mounting substrate 20, protruding from the annular land 10. The additional lands 70 are formed so as to protrude outward from the annular land 10 when viewed in the Z-axis direction. Here, "outward" refers to the outside of the area surrounded by the annular land 10. The additional lands 70 may be formed so as to form a rectangle when viewed in the Z-axis direction. The additional lands 70 are formed so as to protrude from the side 11u of the annular land 10. The additional lands 70 may be formed so as to protrude outward from the annular land 10 when viewed in the Z-axis direction. The shape of the additional lands 70 is not limited to a rectangle, and may be, for example, a trapezoid, a semicircular, a semielliptical, or other shape. The additional lands 70 may be formed so as to protrude from the side 11x or the side 11y, for example.

[0031] The multiple additional lands 70 are arranged at positions symmetrical with respect to the center C of the metal plate 30. The additional lands 70 may be arranged at positions corresponding to the four vertices of an imaginary rectangle, for example. The intersection of the diagonals of this imaginary rectangle is located at the center C.

[0032] In the infrared temperature sensor 100, only annular lands 10 may be arranged between the metal plate 30 and the mounting substrate 20. Specifically, the annular lands 10 are covered by the metal plate 30 when viewed in the Z-axis direction. That is, the annular lands 10 can be used to align the metal plate 30. Furthermore, by roughly matching the size of the outer edges of the metal plate 30 and the annular lands 10, the alignment accuracy can be improved. Also, as shown in FIG. 4, additional lands 70 may be arranged outside the metal plate 30 when viewed in the Z-axis direction. Of the lands formed on the mounting substrate 20, only the annular lands 10 may be arranged in a position overlapping the metal plate 30, and some of the additional lands 70 may be arranged in a position not overlapping the metal plate 30. Furthermore, the claws 31 of the metal plate 30 may be arranged in a position overlapping the additional lands 70 when viewed in the Z-axis direction.

[0033] [First through hole 81] 1 and 3, a first through hole 81 is formed in the mounting substrate 20, penetrating the mounting substrate 20 in the thickness direction. The first through hole 81 is formed in the region 23 inside the annular land 10 when viewed in the Z-axis direction. The first through hole 81 is formed in a position that does not overlap with the sensor chip 40 and the circuit section 50 when viewed in the Z-axis direction. The outer shape of the first through hole 81 may be, for example, circular.

[0034] [Second through hole 82] 4 and 5, second through holes 82 are formed in the metal plate 30, penetrating the metal plate 30 in the plate thickness direction. The second through holes 82 are formed at positions overlapping (corresponding to) the first through holes 81 when viewed in the Z-axis direction. The outer shape of the second through holes 82 may be, for example, circular. The diameter of the second through holes 82 may be larger than the diameter of the first through holes 81. When viewed in the Z-axis direction, the center of the second through holes 82 may be at a different position from the center of the first through holes 81, or may be at the same position.

[0035] [1st Wire 91] The infrared temperature sensor 100 includes a plurality of first wires 91 that electrically connect the sensor chip 40 and the circuit unit 50. The sensor chip 40 may be electrically connected only to the circuit unit 50. The first wires 91 are electrically connected to the sensor chip 40 and the circuit unit 50 via, for example, bonding pads.

[0036] [Third through hole 83] A third through-hole 83 is formed in the metal plate 30, penetrating the metal plate 30 in the plate thickness direction. As shown in Fig. 5, the circuit unit 50 has a rectangular outer shape. The outer shape of the circuit unit 50 has a pair of sides 51, 52 that face each other in the Y-axis direction. The pair of sides 51, 52 are arranged along the X-axis direction.

[0037] A plurality of (for example, two) third through holes 83 are formed in the metal plate 30. The third through holes 83 are formed at positions corresponding to a pair of sides 51 and 52 of the circuit unit 50 when viewed in the Z-axis direction. The "positions corresponding to the sides 51 and 52" may be positions adjacent to the sides 51 and 52 or positions overlapping the sides 51 and 52. The plurality of third through holes 83 are arranged on both sides of the circuit unit 50 in the Y-axis direction. The outer shape of the third through holes 83 may be, for example, substantially triangular. The shape of the third through holes 83 may be substantially rectangular, circular, or may be another shape. The positions of the third through holes 83 may also be other positions. The third through holes 83 expose a portion of the first surface 21 of the mounting substrate 20 upward.

[0038] 4, in the region 23 inside the annular land 10, the through holes penetrating the metal plate 30 may be only the second through hole 82 and the third through hole 83. In the metal plate 30, in the region 23 inside the annular land 10, through holes other than the second through hole 82 and the third through hole 83 may be formed.

[0039] [Second Wire 92] The infrared temperature sensor 100 includes a plurality of second wires 92 that electrically connect the circuit unit 50 and the mounting substrate 20. The second wires 92 are inserted through the third through-holes 83 and connected to the mounting substrate 20. The second wires 92 may be electrically connected to a wiring pattern formed on the first surface 21 of the mounting substrate 20.

[0040] [Solder 110] As shown in FIG. 4, the infrared temperature sensor 100 has a conductive bonding agent 110 formed on an annular land 10. An example of the conductive bonding agent may be solder 110. The conductive bonding agent is not limited to solder. The conductive bonding agent may be, for example, silver paste or another conductive adhesive. The solder 110 is disposed between the annular land 10 and the metal plate 30 in the Z-axis direction. The solder 110 is continuous along the annular land 10. The solder 110 is formed around the entire circumference of the annular land 10. The metal plate 30 is joined to the mounting substrate 20 by the solder 110.

[0041] As will be described later, during manufacturing, the solder 110 does not have to be arranged around the entire circumference of the annular land 10. In the infrared temperature sensor 100, which is a completed product, the solder 110 needs to be arranged around the entire circumference of the annular land 10. In the infrared temperature sensor 100, which is a completed product, the solder 110 is continuous around the entire circumference of the annular land 10.

[0042] [Circuit element 25] 6, the infrared temperature sensor 100 includes a plurality of circuit elements 25 mounted on a mounting substrate 20. The plurality of circuit elements 25 are mounted, for example, on the second surface 22 of the mounting substrate 20. The circuit elements 25 may be, for example, chip resistors, chip capacitors, or other electronic components. The circuit elements 25 include passive elements and active elements such as a microcomputer.

[0043] [Connector 45] The infrared temperature sensor 100 also includes a connector 45 for connection to the outside. The connector 45 is mounted, for example, on the second surface 22 of the mounting substrate 20. The connector 45 is electrically connected to the sensor chip 40, the circuit section 50, and the circuit element 25 mounted on the mounting substrate 20. The connector 45 includes, for example, a power supply terminal and an input / output terminal.

[0044] [Functions and Effects of the Infrared Temperature Sensor 100 According to the Embodiment] The infrared temperature sensor 100 of this embodiment comprises a mounting substrate 20 having an annular land 10, a metal plate 30 mounted on the mounting substrate 20, a sensor chip 40 mounted on the metal plate 30 and detecting infrared rays, a circuit section 50 mounted on the metal plate 30 and amplifying the detection signal output from the sensor chip 40, and a metal cap 60 covering the sensor chip 40 and the circuit section 50. Solder 110 is arranged between the annular land 10 and the metal plate 30, and the solder 110 is formed around the entire circumference of the annular land 10.

[0045] In this infrared temperature sensor 100, the solder 110 is formed around the entire circumference of the annular land 10, thereby preventing fluid (e.g., air) from flowing into the area 23 inside the annular land 10 through the gap between the annular land 10 and the metal plate 30. This prevents the infrared temperature sensor 100 from being affected by the flow of fluid outside the infrared temperature sensor 100, improving the accuracy of temperature measurement. Since the infrared temperature sensor 100 can prevent the inflow of fluid around the infrared temperature sensor 100, fluctuations in the output from the sensor chip 40 can be suppressed. As a result, a low-noise infrared temperature sensor 100 can be achieved.

[0046] In addition, in the infrared temperature sensor 100, the solder 110 is formed around the entire circumference of the annular land 10, thereby strengthening the mechanical bonding strength between the mounting substrate 20 and the metal plate 30. In addition, in the infrared temperature sensor 100, the solder 110 is formed around the entire circumference of the annular land 10, thereby improving thermal uniformity in the metal plate 30. Compared to when the solder 110 is formed partially around the annular land 10, in the infrared temperature sensor 100, temperature unevenness in the metal plate 30 is suppressed and the thermal resistance between the mounting substrate 20 and the metal plate 30 is reduced, thereby improving thermal uniformity. In the infrared temperature sensor 100, the improved thermal uniformity in the metal plate 30 allows for improved temperature measurement accuracy.

[0047] In the infrared temperature sensor 100, the solder 110 is formed around the entire circumference of the annular land 10, thereby improving the resistance of the infrared temperature sensor 100 to external electromagnetic noise. In the infrared temperature sensor 100, the sealing with the annular solder 110 prevents electromagnetic noise from entering through the gap between the mounting substrate 20 and the metal plate 30. In the infrared temperature sensor 100, the metal pattern formed on the first surface 21 of the mounting substrate 20, the annular solder 110, and the metal plate 30 prevent electromagnetic noise from entering the space surrounded by the metal plate 30 and the metal cap 60. In the infrared temperature sensor 100, it is possible to prevent electromagnetic noise from entering from all directions intersecting the Z-axis direction.

[0048] In the infrared temperature sensor 100 according to this embodiment, no land for fixing the metal plate 30 with solder 110 is formed inside the annular land 10. In the infrared temperature sensor 100, no land is formed in the region 23 inside the annular land 10 on the first surface 21 of the mounting substrate 20. The infrared temperature sensor 100 of this aspect facilitates routing of wiring on the first surface 21 of the mounting substrate 20, improving the degree of freedom in designing the wiring pattern. In the infrared temperature sensor 100, no land that would interfere with wiring is formed.

[0049] In the infrared temperature sensor 100, the mounting substrate 20 and the metal plate 30 are firmly bonded thermally and mechanically, so there is no need to form a land inside the annular land 10. Therefore, since no land is arranged inside the annular land 10, the degree of freedom in wiring in the inner region 23 is improved.

[0050] In the infrared temperature sensor 100 according to this embodiment, the sensor chip 40 is mounted in the center of the metal plate 30, and the annular land 10 may be shaped symmetrically with respect to the center C of the metal plate 30. In the infrared temperature sensor 100 of this embodiment, the solder 110 is formed symmetrically with respect to the center C by forming the solder 110 along the annular land 10. Therefore, in the infrared temperature sensor 100, the occurrence of temperature unevenness in the metal plate 30 is suppressed, improving thermal uniformity and temperature measurement accuracy.

[0051] The infrared temperature sensor 100 according to this embodiment may include an additional land 70 formed on the mounting substrate 20 and protruding from the annular land 10. The additional land 70 has the effect of attracting the solder 110 by surface tension. By providing such an additional land 70, the solder 110 disposed on the annular land 10 is attracted by the surface tension of the additional land 70 during manufacturing. This makes it easier for the solder 110 to spread all around the annular land 10. Furthermore, the solder flows onto the additional land 70, which can absorb excess solder on the annular land 10. That is, during manufacturing of the infrared temperature sensor 100, the additional land 70 can act as a buffer, allowing a uniform amount of solder 110 to be formed on the annular land 10. As a result, the bonding strength between the mounting substrate 20 and the metal plate 30 can be improved.

[0052] The infrared temperature sensor 100 according to this embodiment includes a plurality of additional lands 70, which are arranged at positions symmetrical with respect to the center C of the metal plate 30. In the infrared temperature sensor 100 according to this embodiment, the position of the metal plate 30 is stabilized, and variations in the mounting position of the metal plate 30 can be suppressed. Because the additional lands 70 are formed symmetrical with respect to the center C, the metal plate 30 can be positioned with respect to the additional lands 70, thereby positioning the metal plate 30 with respect to the center C. When manufacturing a plurality of infrared temperature sensors 100, individual differences in variations in the mounting position of the metal plate 30 can be suppressed.

[0053] In the infrared temperature sensor 100, a first through hole 81 penetrating the mounting substrate 20 may be formed in the region 23 inside the annular land 10, and a second through hole 82 may be formed in the metal plate 30 at a position corresponding to the first through hole 81 when viewed in the thickness direction of the mounting substrate 20. According to this aspect of the infrared temperature sensor 100, the first through hole 81 and the second through hole 82 can be communicated with each other. For example, if solder is used as the adhesive, the first through hole 81 and the second through hole 82 can be used as relief holes to adjust the pressure in the internal space when baking the adhesive used to bond the metal cap 60 to the metal plate 30 during manufacturing of the infrared temperature sensor 100. When air in the internal space surrounded by the metal plate 30 and the metal cap 60 thermally expands, the air passes through the first through hole 81 and the second through hole 82 and is discharged to the outside. After baking the adhesive, the first through hole 81 and the second through hole 82 may or may not be filled. Furthermore, if the infrared temperature sensor 100 does not use a thermosetting adhesive such as a two-component mixed type or UV curable type, the first through-hole 81 and the second through-hole 82 do not need to be formed.

[0054] In the infrared temperature sensor 100 according to the embodiment, the external shape of the circuit section 50 is a rectangle when viewed in the thickness direction of the metal plate 30, the sensor chip 40 is connected only to the circuit section 50 by a first wire 91, two third through holes 83 are formed in the metal plate 30 at positions corresponding to two sides 51 and 52 of the rectangle when viewed in the thickness direction, a second wire 92 is inserted into the third through holes 83, and the circuit section 50 is electrically connected to the mounting board 20 via the second wire 92.

[0055] In the infrared temperature sensor 100 according to the embodiment, a first through hole 81 penetrating the mounting substrate 20 is formed in the region 23 inside the annular land 10 in the mounting substrate 20, a second through hole 82 is formed in the metal plate 30 at a position corresponding to the first through hole 81 when viewed in the thickness direction of the mounting substrate 20, the outline of the circuit unit 50 is rectangular when viewed in the thickness direction of the metal plate 30, and the sensor chip 40 is connected only to the circuit unit 50 by a first wire 91, two third through holes 83 are formed in the metal plate 30 at positions corresponding to two sides 51, 52 of the rectangle when viewed in the thickness direction, and a second wire 92 is inserted through the third through hole 83, and the circuit unit 50 is electrically connected to the mounting substrate 20 via the second wire 92, and in the region 23 inside the annular land 10, the second through hole 82 and the third through hole 83 are the only through holes penetrating the metal plate.

[0056] As a result, by minimizing the number of through holes formed in the metal plate 30, the area of ​​the metal plate 30 can be increased, thereby improving the electromagnetic noise resistance.

[0057] In the infrared temperature sensor 100 according to the embodiment, only the annular land 10 is arranged as a land between the metal plate 30 and the mounting substrate 20, and the additional land 70 is arranged outside the metal plate 30 when viewed in the thickness direction of the metal plate 30. In the infrared temperature sensor 100 of this aspect, no land is arranged inside the annular land 10, which improves the degree of freedom of wiring in the inner region 23.

[0058] In the infrared temperature sensor 100, a circuit element 25 including electronic components can be arranged on the second surface 22 of the mounting substrate 20. This eliminates the need to arrange electronic components on the first surface 21 of the mounting substrate 20, allowing the area of ​​the metal plate 30 to be fully utilized, improving thermal uniformity. As a result, the temperature difference in the internal structure of the infrared temperature sensor 100 can be reduced, improving the measurement accuracy of the infrared temperature sensor 100. The internal structure of the infrared temperature sensor 100 includes the sensor chip 40 and circuit unit 50, which are arranged in the internal space between the metal plate 30 and the metal cap 60.

[0059] Furthermore, the infrared temperature sensor 100 can improve its resistance to electromagnetic noise by increasing the area of ​​the metal plate 30. In the infrared temperature sensor 100, the proportion of the metal plate 30 surrounding the sensor chip 40, which is the sensor element, can be increased. The infrared temperature sensor 100 can suppress the intrusion of electromagnetic waves traveling in the Z-axis direction, which is perpendicular to the metal plate 30. In the infrared temperature sensor 100, the metal plate 30 can improve the shielding effect against electromagnetic waves traveling in the Z-axis direction, thereby improving its noise resistance.

[0060] In the infrared temperature sensor 100 according to this embodiment, the mounting substrate 20 has a first surface 21 and a second surface 22 that face each other in the thickness direction of the mounting substrate 20. The metal plate 30 and the annular land 10 are arranged on the first surface 21, and the circuit elements 25 are arranged on the second surface 22. According to the infrared temperature sensor 100 of this aspect, the circuit elements 25 can be arranged on the second surface 22 of the mounting substrate 20, and the number of circuit elements 25 arranged on the first surface 21 of the mounting substrate 20 can be reduced. In the infrared temperature sensor 100, the number of circuit elements 25 arranged on the first surface 21 of the mounting substrate 20 can be reduced, and the area of ​​the metal plate 30 can be increased.

[0061] [Method of manufacturing the infrared temperature sensor 100 according to the embodiment] Next, a description will be given of a manufacturing method of the infrared temperature sensor 100 according to the embodiment. The manufacturing method of the infrared temperature sensor 100 includes the steps of forming solder on the annular lands 10 formed on the first surface 21 of the mounting substrate 20 and mounting a metal plate 30 on the mounting substrate 20, mounting a sensor chip 40 and a circuit unit 50 on the metal plate 30, and mounting a metal cap 60 on the metal plate 30 so as to cover the sensor chip 40 and the circuit unit 50.

[0062] In the process of mounting the metal plate 30, solder 110 is formed intermittently on the annular lands 10, and then the metal plate 30 is mounted. In the process of mounting the metal plate 30, after the metal plate 30 is mounted, the metal plate 30 is heated by reflow, so that the solder 110 is formed all around the annular lands 10, and the metal plate 30 is fixed to the mounting board 20 via the solder 110.

[0063] In the process of mounting the metal plate 30, a method can also be used in which cream solder is applied all around the annular land 10, the metal plate 30 is placed on the mounting board 20, and heated by reflow.

[0064] The method for manufacturing the infrared temperature sensor 100 according to this embodiment can manufacture the infrared temperature sensor 100 described above.

[0065] [Annular land 10B according to the first modified example] Next, the annular land 10B according to the first modification will be described. Fig. 6 is a plan view illustrating the annular land 10B according to the first modification. As shown in Fig. 6, the annular land 10B may have a rectangular shape. The infrared temperature sensor 100 may include a mounting substrate 20 having rectangular annular lands 10B instead of the mounting substrate 20 having octagonal annular lands 10.

[0066] [Annular land 10C according to the second modified example] Next, an annular land 10C according to a second modification will be described. Fig. 7 is a plan view illustrating an annular land 10C according to the second modification. As shown in Fig. 7, the annular land 10C may have a circular shape. The infrared temperature sensor 100 may include a mounting substrate 20 having a circular annular land 10C instead of the mounting substrate 20 having an octagonal annular land 10.

[0067] It should be noted that the present invention is not limited to the configurations shown here, and other embodiments may be possible in which other components are combined with the configurations described in the above embodiments. In this regard, the present invention can be modified within the scope of the present invention, and can be appropriately determined depending on the application form. [Explanation of symbols]

[0068] 100: infrared temperature sensor, 10, 10B, 10C: annular land, 20: mounting board, 21: first surface, 22: second surface, 25: circuit element, 30: metal plate, 51: first side, 52: second side, 40: sensor chip, 50: circuit section, 60: metal cap, 63: lens (transmissive section), 70: additional land, 81: first through hole, 82: second through hole, 83: third through hole, 91: first wire, 92: second wire, 110: solder (conductive bonding agent), X: X-axis direction, Y: Y-axis direction, Z: Z-axis direction (plate thickness direction).

Claims

1. a mounting substrate having an annular land; a metal plate mounted on the mounting board; a sensor chip mounted on the metal plate to detect infrared rays; a circuit section mounted on the metal plate and amplifying a detection signal output from the sensor chip; a metal cap having a transmitting portion that transmits infrared light and that covers the sensor chip and the circuit portion, a conductive bonding agent is disposed between the annular land and the metal plate; The conductive bonding agent is formed along the entire circumference of the annular land.

2. 2. The infrared temperature sensor according to claim 1, wherein no land for fixing the metal plate with a conductive bonding agent is formed inside the annular land.

3. The sensor chip is mounted at the center of the metal plate, 2. The infrared temperature sensor according to claim 1, wherein the annular land is shaped symmetrically with respect to the center of the metal plate.

4. The infrared temperature sensor according to claim 1 , further comprising an additional land formed on the mounting substrate and protruding from the annular land.

5. a plurality of said additional lands; The infrared temperature sensor according to claim 4 , wherein the plurality of additional lands are arranged at positions symmetrical with respect to the center of the metal plate.

6. a first through-hole penetrating the mounting substrate is formed in an area inside the annular land; The infrared temperature sensor according to claim 1 , wherein the metal plate has a second through hole formed at a position corresponding to the first through hole when viewed in the thickness direction of the mounting substrate.

7. The circuit portion has a rectangular outer shape when viewed in the thickness direction of the metal plate, the sensor chip is connected only to the circuit section by a first wire; Two third through holes are formed in the metal plate at positions corresponding to two sides of the rectangle when viewed in the plate thickness direction, a second wire is inserted through the third through hole; The infrared temperature sensor according to claim 1 , wherein the circuit section is electrically connected to the mounting board via the second wire.

8. a first through-hole penetrating the mounting substrate is formed in an area inside the annular land; a second through hole is formed in the metal plate at a position corresponding to the first through hole when viewed in the thickness direction of the mounting substrate; The circuit portion has a rectangular outer shape when viewed in the thickness direction of the metal plate, the sensor chip is connected only to the circuit section by a first wire; Two third through holes are formed in the metal plate at positions corresponding to two sides of the rectangle when viewed in the plate thickness direction, a second wire is inserted through the third through hole; the circuit unit is electrically connected to the mounting substrate via the second wire; The infrared temperature sensor according to claim 1 , wherein the second through-hole and the third through-hole are the only through-holes that penetrate the metal plate in the region inside the annular land.

9. the annular land is the only land disposed between the metal plate and the mounting substrate, 6. The infrared temperature sensor according to claim 4, wherein a part of the additional land is disposed on the outer side of the metal plate when viewed in the thickness direction of the metal plate.

10. the mounting substrate has a first surface and a second surface that face each other in a thickness direction of the mounting substrate, the metal plate and the annular land are disposed on the first surface, The infrared temperature sensor according to claim 1 , wherein a circuit element is disposed on the second surface.

11. forming solder on an annular land formed on a first surface of a mounting substrate, and mounting a metal plate on the mounting substrate; mounting a sensor chip and a circuit unit on the metal plate; and mounting a metal cap on the metal plate so as to cover the sensor chip and the circuit unit, In the step of mounting the metal plate, After the solder is intermittently formed on the annular land, the metal plate is mounted on the annular land; After mounting the metal plate, the solder is formed around the entire circumference of the annular land by reflow, and the metal plate is fixed to the mounting substrate via the solder.

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