JP2012215445A - Infrared sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared sensor incorporating an optical filter, having an element shape which is compact, thin and simple, and in which, when used for a non-dispersive infrared absorption type (Non-Dispersive InfraRed) gas densitometer (hereinafter called an NDIR gas densitometer), an infrared-light receiving window is placed sideways to be surface-mounted on a component mounting board for achieving compactness and thinning in addition to an ordinary mounting method.SOLUTION: An infrared sensor comprises: an optical filter sealed in a rectangular parallelepiped sealing member, for selecting penetrating infrared light; a sensor element for detecting the infrared light having penetrated the optical filter; a plurality of connection terminals for outputting a detection signal detected by the sensor element to the outside; and a connection wire for connecting the sensor element with the connection terminals. The connection terminals are formed in an L-shape bending inwards and are exposed from the sealing member over at least two adjacent surfaces.

Description

  The present invention relates to an infrared sensor, and more particularly to a small infrared sensor that can be used in a non-dispersive infrared gas concentration meter (hereinafter referred to as an NDIR gas concentration meter).

  Conventionally, as an infrared gas concentration meter that measures the gas concentration in the atmosphere, an NDIR gas concentration meter that utilizes the fact that the wavelength of infrared rays (IR: Infrared) absorbed varies depending on the type of gas. The NDIR gas densitometer measures the gas concentration by detecting the amount of infrared radiation absorbed in accordance with the type of gas to be detected. This NDIR gas concentration meter is configured by combining an infrared light source, a filter that transmits infrared rays limited to the wavelength of the gas to be detected, and an infrared sensor, and detects the amount of infrared absorption at a predetermined wavelength by detecting the amount of infrared absorption with the infrared sensor. The concentration is measured. Infrared sensors used in NDIR gas concentration meters are generally divided into thermal infrared sensors and quantum infrared sensors.

A thermal infrared sensor is a sensor that uses infrared energy as heat, and the temperature of the sensor itself rises due to the infrared thermal energy, and the effects (resistance change, capacitance change, electromotive force, spontaneous polarization) due to the temperature rise. An element that converts an electrical signal. This thermal infrared sensor includes a pyroelectric type (PZT, LiTaO ₃ ), a thermoelectromotive force type (thermopile, thermocouple), etc., and the sensitivity does not depend on the wavelength, and cooling is unnecessary. However, the response speed is slow and the detection capability is not so high.

  In the case of this thermal infrared sensor, for the purpose of blocking heat, an optical filter that transmits infrared rays is bonded to the opening of the can package, and an infrared detection element that detects infrared rays transmitted through the optical filter is installed in the can package. The shape housed inside is used. In addition, as a thermopile sensor, in order to simplify, downsize, and improve durability, the can package is not adopted, and a MEMS structure and an optical filter are provided around the detection element forming part of the infrared sensor. A structure in which a predetermined gap is ensured to form a mold resin has been proposed.

  On the other hand, a quantum infrared sensor is a sensor that uses electrons and holes generated by photons when an infrared ray is irradiated on a semiconductor, and is a photoconductive type (such as HgCdTe) or a photovoltaic type (such as InAs). There is. This quantum infrared sensor has the characteristics that the sensitivity depends on the wavelength, has high sensitivity, and has a high response speed, but needs to be cooled. Therefore, it is generally used together with a cooling mechanism such as a Peltier element sealed in a can package or a Stirling cooler. A quantum infrared sensor that can operate at room temperature has also been proposed.

  For example, in Patent Document 1, as shown in FIG. 10, a waveguide 100 that forms a passage for a gas to be detected (such as carbon dioxide), a light source 101 that irradiates infrared rays to both ends of the waveguide 100, and a sensor An infrared gas concentration meter with 102 is described. This densitometer uses a first optical filter 103 having a transmission window in the infrared absorption band of the gas to be detected, and a second optical filter 104 having a transmission window in a band in which there is no infrared absorption of the gas to be detected. The gas concentration is measured by detecting the amount of infrared light transmitted through each of the first optical filter and the second optical filter by the sensor 102.

  In recent years, in order to reduce the size and thickness of the apparatus, an NDIR gas concentration meter in which a gas detection structure and a signal processing operation unit are integrated on a printed board has been proposed. As shown in FIG. 11, Patent Document 2 discloses that a gas cell 212, a light source 205, a photodetector (infrared sensor) 207 incorporating an optical filter, and a control / calculation electronic unit 206 on a component surface mounting substrate 209. A gas concentration meter is described that makes it possible to reduce the size of the gas detection configuration.

  The photodetector 207 used in the gas concentration meter of Patent Document 2 is provided on the same mounting substrate 209 as the light source, and is mounted with the infrared detection surface facing the light source 205. Since this photodetector is configured such that a substrate connection terminal is provided on one surface of the photodetector 207 opposite to the detection surface, the connection terminal of the photodetector 207 is connected to the mounting substrate. Therefore, a substrate 209 is laminated on the connection terminal 218 portion, and the photodetector terminal 218 is sandwiched between the laminated substrates 209. That is, in order to directly mount the infrared sensor 207 and the light source 205 on the component surface mounting substrate 209 in opposition, the concave structure 208 is adopted on the substrate, and the light detection is performed so that the detection surface of the photodetector is in the horizontal direction. It is disclosed that a small and thin NDIR gas concentration meter is realized by tilting and mounting the device.

  In addition, a quantum infrared sensor that can operate at room temperature does not need to be shielded from heat and can be easily configured in a mold resin. As a general mold resin package structure, for example, a configuration of a small magnetoelectric conversion element capable of reducing the mounting area as shown in FIG. 12 has been proposed (Patent Document 3).

  In the device disclosed in Patent Document 3, a pellet 124 having a magnetic sensing portion and an internal electrode is placed on a lead frame 122, and the lead frame 122 and the internal electrode are electrically connected by a thin metal wire 125. And is formed of a resin 121 that seals the pellet 124, the fine metal wire 125, and a part of the lead frame 122. The shape of the resin 121 is almost a rectangular parallelepiped, and the lead frame serves as a terminal for electrical connection with the outside. The surface 127 is arranged so as to be in contact with one side of one surface of the rectangular parallelepiped, and is arranged to be a surface on which the cut surface 123 corresponding to the side surface is mounted. Because the orientation can be parallel to the component mounting board (mounting surface) 128, not only the magnetic flux density in the vertical direction but also the magnetic flux density in the horizontal direction can be detected. And compact capable Rukoto discloses providing a thin magneto-electric transducer.

  That is, in the device described in Patent Document 3, not only the magnetic flux density in the vertical direction with respect to the mounting surface but also the magnetic flux in the horizontal direction is formed by forming the Hall element in a pellet shape and mounting it through the lead frame. Vertical mounting that can detect density is possible. This magnetoelectric conversion element is extremely thin and downsized.

JP 2008-82862 A Special table 2008-525815 JP 2005-93823 A

  As described above, in order to reduce the size and thickness of the NDIR gas concentration meter, as described in Patent Document 2, a concave structure is adopted on the substrate, and the detection surface of the photodetector (infrared sensor) becomes sideways. In this way, the infrared sensor is knocked down. This is because a can package type infrared sensor having a substrate connection terminal on the back side of the infrared detection surface is employed. However, this can package type configuration has a limitation in the mounting method, which leads to a complicated substrate structure, which is an obstacle to further downsizing and thinning the NDIR gas concentration meter.

  Further, the package structure described in Patent Document 3 employed as a general mold resin package is not suitable as a configuration of the infrared sensor portion of the NDIR gas concentration meter. In the NDIR gas concentration meter, it is necessary to incorporate an infrared sensor and an optical filter. However, in the package (mold resin 121) of Patent Document 3, infrared rays are introduced into the package, or an infrared sensor and an optical filter are incorporated. Because you can't. That is, in the package of Patent Document 3, it is necessary to provide the wire 125 (metal thin wire) for connecting the chip (the Hall element pellet 124) and the lead frame 122 on the infrared detection surface side, and an optical filter cannot be incorporated. Furthermore, in the package of Patent Document 3, since the area of the side surface 123 that is a joint surface with the component mounting board 124 is smaller than the area of the bottom surface 127 of the terminal, it is applied to the board by the tension of the solder 126 when mounted on the component mounting board 128. However, there were problems such as the package tilting.

  The present invention has been made in view of such problems, and the object of the present invention is to have a small, thin and simple element shape. In addition to a normal mounting method, the NDIR gas concentration meter is small in size. An object of the present invention is to provide an infrared sensor with a built-in optical filter that can be mounted on a surface of a component mounting board by laying down an infrared receiving window in order to realize a reduction in thickness and thickness.

  The present invention has been made to achieve such an object. The invention according to claim 1 is an optical filter for selecting transmitted infrared rays sealed in a rectangular parallelepiped sealing member; A sensor element that detects infrared rays transmitted through the filter, a plurality of connection terminals that output detection signals detected by the sensor element to the outside, and a connection wiring that connects the sensor element and the connection terminals; The connection terminal is an infrared sensor characterized in that it is formed in an L shape bent inward and is exposed from the sealing member over at least two adjacent surfaces.

  According to a second aspect of the present invention, in the infrared sensor according to the first aspect, the infrared sensor includes an upper structure in which an optical filter is sealed, a lower portion in which the sensor element, the connection terminal, and the wiring terminal are sealed. It is characterized by being bonded to a structure.

  The invention according to claim 3 is the infrared sensor according to claim 1, wherein the connection terminal is exposed over the entire height of the side surface of the infrared sensor.

  According to a fourth aspect of the present invention, in the infrared sensor according to the first to third aspects, the connection wiring is a flip chip bond.

  According to a fifth aspect of the present invention, in the infrared sensor according to the first to third aspects, the connection wiring is a bonding wire.

It is sectional drawing for demonstrating Example 1 of the infrared sensor which concerns on this invention. It is an external view for demonstrating Example 1 of the infrared sensor which concerns on this invention. It is Example 1 for demonstrating Example 1 of the infrared sensor which concerns on this invention. It is Example 2 for demonstrating Example 1 of the infrared sensor which concerns on this invention. It is sectional drawing for demonstrating another form of Example 1 of the infrared sensor which concerns on this invention. It is sectional drawing for demonstrating Example 2 of the infrared sensor which concerns on this invention. It is sectional drawing for demonstrating another form of Example 2 of the infrared sensor which concerns on this invention. It is sectional drawing for demonstrating Example 3 of the infrared sensor which concerns on this invention. It is sectional drawing for demonstrating another form of Example 3 of the infrared sensor which concerns on this invention. It is a figure for demonstrating the structure of the conventional infrared gas concentration meter. It is a figure for demonstrating the conventional NDIR gas concentration meter comprised on the printed circuit board. It is a figure which shows an example of a general mold resin package structure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the first embodiment, and FIG. 2 is a diagram illustrating an appearance of the infrared sensor according to the first embodiment. As shown in FIG. 1, the infrared sensor 10 includes a sensor element 1, an optical adjustment unit 2, an optical filter 3, a light receiving window 4, a connection wiring 5, a connection terminal 6, and a sealing member 7. Configured.

  The infrared sensor 10 of the present embodiment has two detection units in order to correspond to the single light source two-wavelength comparison NDIR gas concentration meter. Corresponding to the two detection units, two sensor elements 1, two optical adjustment units 2, two optical filters 3, two light receiving windows 4 are provided, and eight connection terminals 6 are further provided. ing. FIG. 2 is a diagram showing the appearance of the infrared sensor according to the first embodiment. FIG. 2A shows two optical filters 3 and a light receiving window 4, and FIG. 2B shows two optical filters. Eight connection terminals 6 provided corresponding to the two sensor elements 1 optically connected to the filter 3 are shown.

  The sensor element 1 is an infrared sensor element that converts infrared light received by the light receiving surface 1a into an electrical signal, and a quantum infrared sensor that can operate at room temperature can be used. Since the quantum infrared sensor is operable at room temperature, the sensor element 1 can be directly sealed using the sealing member 7. The optical adjustment unit 2 is a filter that is provided on the light receiving surface 1 a of the sensor element 1 and prevents infrared rays from being reflected by the light receiving surface 1 a of the sensor element 1.

  Each of the optical filters 3 is provided on the upstream side of the optical adjustment unit 2. One of the two optical filters 3 is an optical filter that transmits infrared light having a wavelength that is absorbed by the detection target gas, and the other is the detection target. An optical filter that transmits light having a predetermined wavelength other than the wavelength absorbed by the gas can be used. For example, when the gas to be detected is carbon dioxide, the one-light source / two-wavelength comparison NDIR gas densitometer transmits an optical filter matched to the absorption characteristic of carbon dioxide and infrared light having a wavelength of about 3.9 μm as reference light. An optical filter can be used. Two wavelengths are selected by these two optical filters 3, and the selected infrared rays are detected by the infrared sensor element 1 optically connected to the downstream side of each optical filter 3.

  In the NDIR gas concentration meter to which the infrared sensor 10 of the present invention is applied, the gas concentration of the gas to be measured can be quantified by the following calculation. According to the Lambert-Beer law, the gas concentration c is expressed by the following equation, where the incident light intensity Ig0 of the gas absorption band, the transmitted light intensity Ig of the gas absorption band, the absorbance coefficient ε, and the gas path length L Can be represented.

  Since the incident light intensity Ig0 in the gas absorption band is proportional to the transmitted light intensity Ib in the wavelength band of the reference light without absorption, if the proportionality coefficient is α,

  Accordingly, the gas concentration is quantified by the following equation using the transmitted light amount in the gas absorption band and the transmitted light amount in the wavelength band of the reference light without gas absorption.

  As described above, since the infrared sensor 10 is provided with the detection unit that can detect the transmitted light amount in two different wavelength bands, the transmitted light amount in the infrared absorption band wavelength of the detection target gas and the reference light without absorption of the detection target gas. It is possible to take a ratio with the amount of transmitted light in the wavelength band, and it is possible to correct a change in the output signal with time due to deterioration of the light source or contamination of the optical filter.

  The connection terminals 6 are connection terminals for connecting the sensor elements 1 to the substrate, and four connection terminals 6 are provided around each sensor element 1 in correspondence therewith. For the connection terminal 6, an L-shaped metal piece having a predetermined width W can be used. The connection terminal 6 is disposed so as to be exposed from the sealing member 7 over two adjacent surfaces of the infrared sensor 10 in a state of being bent inward of the package as illustrated. The length of the connection terminal 6 exposed on the two surfaces of the infrared sensor 10 may be at least as long as it can be used as the connection terminal, for example, 0.2 mm or more. Further, the connection terminals 6 are not limited to four each around the sensor element 1, and the connection terminals 6 shared by the two sensor elements 1 may be used.

  Furthermore, when the horizontal length of the infrared sensor 10 (the size in the horizontal direction in FIG. 1) is configured to be larger than the vertical length (the size in the vertical direction in FIG. 1), the connection exposed in the vertical direction. The length of the terminal 6 is preferably configured to be at least half the length of the infrared sensor 10 itself in the vertical direction. This is because it can be stably fixed to the substrate during the vertical mounting described later.

  The connection wiring 5 is a bonding wire for connecting the sensor element 1 to the connection terminal 6. Since the L-shaped connection terminal 6 is provided in a state of being bent inside, the connection terminal 6 is exposed from the sealing member 7 over two adjacent surfaces of the infrared sensor 10 while the connection terminal 6 One surface can be in the same direction as the bottom surface of the sensor element 1, and wire bonding can be easily performed.

  The sealing member 7 opens the two light receiving windows 4 for introducing infrared rays into the optical filter 3, and the sensor element 1, the optical adjustment unit 2, and the like described above so that the two surfaces of the connection terminal 6 are exposed. A resin that seals the optical filter 3, the connection wiring 5, and the connection terminal 6 to define the outer shape of the rectangular parallelepiped infrared sensor 10.

  As described above, the infrared sensor 10 according to the present embodiment has a configuration in which the wiring portions 5 and 6 are not complicated and the wire bonding is easy, so that the sensor shape can be made small and simple.

  Furthermore, in this infrared sensor 10, since the connection terminal 6 is exposed over two adjacent surfaces of the infrared sensor 10, and the exposed portions have sufficient areas, the light receiving surface 1a of the sensor element 1 is perpendicular to the substrate. Two mountings are possible: vertical mounting (mounting example 1) and horizontal mounting (mounting example 2) in which the light receiving surface 1a of the sensor element 1 is horizontal to the substrate. Two implementation examples will be described with reference to FIGS.

Mounting example 1 (Vertical mounting)
FIG. 3 is a diagram for explaining a mounting example 1 of the infrared sensor according to the present embodiment. This mounting example has a configuration in which the light receiving surface 1a of the sensor element 1 is perpendicular to the substrate 11 (the light receiving window is opened sideways). This mounting example is suitable, for example, when mounting on a gas concentration meter configured to detect infrared rays that enter the substrate 11 in the horizontal direction with respect to the light receiving surface 1a of the sensor element 1.

  In the infrared sensor 10 used in this mounting example, of the four connection terminals corresponding to one sensor element 1 (see FIG. 2), only two connection terminals 6 on the side connected to the substrate are connected to the sensor element 1. The remaining two connection terminals 6 are dummy.

  When mounting the infrared sensor 10, for example, it can be mounted by a solder reflow method. A paste-like solder 13 is placed on the wiring land 12 of the substrate 11 by a method such as printing. The infrared sensor 10 is mounted on the substrate 11 by pressing and mounting the connection terminal side portion 6a of the infrared sensor 10 in the direction of the substrate 11, heating and melting the solder 13, and then cooling and solidifying the solder 13. Since the solder 13 is pressed and mounted on the paste-like solder 13, the solder 13 is also spread to the connection terminal bottom 6b. Therefore, the infrared sensor 10 is connected on the two surfaces of the connection terminal 6.

  In the infrared sensor 10 of this embodiment, since the connection terminal 6 exposes the connection portion across the two surfaces of the sealing member, the connection land 6 and the wiring land 12 of the component surface mounting substrate 11 are also mounted vertically. A large solder joint area can be secured between the two. For this reason, even in the case of vertical mounting, the mounting strength is strengthened, and the tilt due to the solder tension at the time of mounting can be suppressed.

Mounting example 2 (Horizontal mounting)
FIG. 4 is a diagram for explaining a mounting example 2 of the infrared sensor of the present embodiment. This mounting example has a configuration in which the light receiving surface 1a of the sensor element 1 is perpendicular to the substrate 11 (the light receiving window is opened upward). This mounting example is suitable, for example, when mounted on a gas concentration meter configured to detect infrared rays that enter the substrate 11 from the vertical direction with respect to the light receiving surface 1a of the sensor element 1.

  Also in this mounting example, the infrared sensor 10 can be mounted in the same procedure as the mounting example 1 except that the direction of the infrared sensor 10 with respect to the substrate 11 is different. In the infrared sensor 10 of the present embodiment, since the connection terminal 6 exposes the connection portion across the two surfaces of the sealing member, the connection terminal 6 and the component surface mounting can be performed in the same manner as the vertical mounting even when the mounting is horizontal. A wide solder joint area can be secured between the wiring lands 12 of the substrate 11 and the connection terminals 6 are provided at both ends of the infrared sensor. Therefore, the mounting strength is enhanced, and the inclination due to the solder tension during mounting can be suppressed. .

  As described above, according to the present embodiment, a small and simple sensor shape can be obtained, and vertical mounting (mounting example 1) in which the light receiving surface 1a of the sensor element 1 is perpendicular to the substrate, and light reception of the sensor element 1 are achieved. It is possible to configure an infrared sensor that can be mounted in two ways: horizontal mounting (mounting example 2) in which the surface 1a is horizontal to the substrate.

(Second Embodiment)
FIG. 5 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the second embodiment. The infrared sensor 20 of the present embodiment has a configuration using a flip chip bond 8 instead of the wire bonding used as the connection wiring between the sensor element and the connection terminal in the first embodiment.

  In the present embodiment, four connection terminals 16 are provided around one sensor element 1. As each connection terminal 16, an L-shaped metal piece having a predetermined width can be used. The connection terminal 16 is arranged so as to be exposed from the sealing member 7 over two adjacent surfaces of the infrared sensor 10 in a state of being bent inward of the package as shown in the figure. The lengths of the connection terminals 16 exposed on the two surfaces of the infrared sensor 10 may be at least as long as they can be used as connection terminals, for example, 0.2 mm or more.

  Unlike the first embodiment, the connection terminal 16 of the present embodiment is bent along two adjacent surfaces. One side of the connection terminal 16 extends to a position below the sensor element 1, and a partial upper surface of the connection terminal 16 and the bottom surface of the sensor element 1 are connected by a flip chip bond 8. As shown in this embodiment, if the configuration is to be connected by flip chip bonding 8, there is no need to arrange the connection portion of the connection terminal on the side of the sensor element 1, so that the infrared sensor is more than the configuration of the first embodiment. 20 can be further downsized.

  Further, when the horizontal length (length in the left-right direction in the drawing) of the infrared sensor 20 is configured to be larger than the vertical length (size in the vertical direction in the drawing), the connection terminal 16 exposed in the vertical direction. The length is preferably configured to be at least half the length of the infrared sensor 20 in the vertical direction.

  The infrared sensor 20 of this embodiment can also be applied in the same mounting example as the first embodiment.

  As described above, according to the present embodiment, in addition to the same effects as those of the first embodiment, a further miniaturized infrared sensor can be configured.

(Third embodiment)
FIG. 6 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the third embodiment. In the infrared sensor 30 of the present embodiment, instead of the configuration in which the infrared sensor 10 is integrally sealed with the sealing member 7 in the first embodiment, an upper structure 30a having an upper half configuration having the optical filter 3, A lower structure 30b having a configuration of a lower half 30b having the sensor element 1 is created, and these two structures 30a and 30b are bonded to each other via an adhesive layer 9 to form an infrared sensor 30. . Other configurations are the same as those of the first embodiment.

  The upper structure 30a is configured by sealing the optical filter 3 connected to the light receiving window 4 with a sealing member 18a. The lower structure 30b is configured by sealing the sensor element 1 having the optical adjustment unit 2, the connection wiring 5 corresponding to the sensor element 1, and the connection terminal 6 with a sealing member 18b. The adhesive layer 9 can be constituted by a method of bonding with an adhesive or a method of heat-sealing.

  In this embodiment, an example in which wire bonding is used as the connection wiring 5 is given. Similarly, when the flip chip bond 8 is used as in the second embodiment, the infrared sensor of the second embodiment is used. A structure in which two structures having the upper half 20 as the upper structure 30a and the lower half as the lower structure 30b are separately formed can be bonded together via the adhesive layer 9.

  As described above, according to the present embodiment, in addition to the same effects as those of the first embodiment and the second embodiment, the optical filter is held by the separate sealing member and joined by the adhesive layer. An infrared sensor that can easily change the type and thickness of the optical filter and the size of the light receiving window can be configured.

(Fourth embodiment)
FIG. 7 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the fourth embodiment. The infrared sensor of the present embodiment is an example in which an alignment structure 19 is provided on one side surface of the first sealing member 18a of the third embodiment.

  The alignment structure 19 is formed on the side surface of the lower structure 40b when the center positions of the optical filter 3 and the light receiving window 4 provided in the upper structure 40a and the sensor element 1 provided in the lower structure 40b are aligned. A part of the sealing member 18a of the upper structure 40a is protruded so as to come into contact. In the infrared sensor of the present invention, only two connection terminals exposed on one side surface of the sealing member among the four connection terminals arranged to be exposed on both side surfaces with respect to one sensor element 1 are electrically connected to the infrared sensor. Therefore, there is no problem even if the alignment structure 19 protrudes on one side.

  As described above, according to the present embodiment, in addition to the same effects as those of the third embodiment, an infrared sensor that prevents the optical filter from being displaced can be configured.

(Fifth embodiment)
FIG. 8 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the fifth embodiment. The infrared sensor 50 of the present embodiment has a configuration in which the connection terminal 26 is exposed on the lower surface of the infrared sensor 50 and is exposed over the entire height of the side surface of the infrared sensor 50.

The connection terminal 26 may be configured by a single member, but may be configured by laminating a plurality of conductor sheets because the entire height of the side surface of the sealing member is large. For example, as shown in the figure, two members, that is, an L-shaped first connection terminal 26a and a plate-like second connection terminal 26b may be electrically connected. Also,
The first connection terminal 26 a has a connection surface 26 c parallel to the lower surface of the sensor element 1 so that the bonding wire 5 for connecting to the sensor element 1 can be provided.

  As described above, according to this embodiment, since the connection terminals are exposed over the entire height of both side surfaces of the infrared sensor package, a wider solder joint area is ensured between the connection terminals and the wiring lands of the component surface mounting board. it can. For this reason, it becomes possible to suppress the inclination by mounting strength or solder tension at the time of mounting.

(Sixth embodiment)
FIG. 9 is a cross-sectional view illustrating a schematic configuration of the infrared sensor according to the sixth embodiment. The infrared sensor 60 of the present embodiment has a configuration using flip chip bonding instead of the configuration using wire bonding as the connection wiring between the sensor element and the connection terminal in the fifth embodiment. Other configurations are the same as those of the fifth embodiment.

  The connection terminal 26 is exposed on the bottom surface of the package and is exposed over the entire height of both side surfaces of the package. In the connection terminal 26 of the present embodiment, the portion of the connection terminal 26 exposed on the bottom surface of the package extends to the lower part of the sensor element 1 in order to make a connection with the sensor element 1 by flip chip bonding.

  As described above, according to the present embodiment, the connection terminals are exposed over the entire height of both sides of the package of the infrared sensor in the package adopting the flip lip bond connection, similarly to the package employing the bonding wire. A wider solder joint area can be ensured between the connection terminal and the wiring land of the component surface mounting board. For this reason, it becomes possible to suppress the inclination by mounting strength or solder tension at the time of mounting.

  In the above embodiment, the resin is molded integrally with two wavelengths, thereby realizing a small-sized infrared sensor that suppresses the temperature difference between the sensors and the difference in the amount of received light, but includes an optical filter of each wavelength. Infrared sensors may be used as infrared sensors by sealing them one by one and arranging them in pairs. In other words, two types of infrared light receiving structures are configured so that one type of detection target gas can be stably measured against deterioration of the light source or changes in the output signal with time due to contamination of the optical filter. Instead, if it is a simple measurement, one set of configurations for detecting the absorption wavelength of the detection target gas may be used. Also, when detecting a plurality of gases, the reference wavelength and the plurality of sets of detection target gases are detected. The structure which detects an absorption wavelength may be sufficient. Similarly, when a plurality of gases are detected, a plurality of sets of optical filters and one optical filter for transmitting reference light may be resin-molded as a single body. Furthermore, when a plurality of sensors are resin-molded as a single body, at least one of them may have no optical filter for the purpose of monitoring the amount of infrared light.

DESCRIPTION OF SYMBOLS 1 Sensor element 2 Optical adjustment part 3 Optical filter 4 Receiving window 5 Bonding wire (connection wiring)
6, 16, 26 Connection terminal 7, 18a, 18b Sealing member, sealing member 8 Flip chip (connection wiring)
9 Adhesive layer
10, 20, 30, 40, 50, 60 Infrared sensor 11 Component surface mounting board 12 Land 13 Solder

Claims (5)

An optical filter that is sealed in a rectangular parallelepiped sealing member that selects infrared rays that pass through, a sensor element that detects infrared rays that pass through the optical filter, and a plurality of detection signals that are detected by the sensor elements are output to the outside. A connection terminal, and a connection wiring for connecting the sensor element and the connection terminal,
The connection terminal is formed in an L shape bent inward, and is exposed from the sealing member over at least two adjacent surfaces.   The infrared sensor is formed by bonding an upper structure in which an optical filter is sealed and a lower structure in which the sensor element, a connection terminal, and a wiring terminal are sealed. The infrared sensor described in 1.   The infrared sensor according to claim 1, wherein the connection terminal is exposed over the entire height of the side surface of the infrared sensor.   The infrared sensor according to claim 1, wherein the connection wiring is a flip chip bond.   The infrared sensor according to claim 1, wherein the connection wiring is a bonding wire.

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