JP2013044560A - Infrared sensor and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface mounted infrared sensor and a manufacturing method of the same which achieve secure joining of a package and a package lid, with an easy structure.SOLUTION: An infrared sensor 1 includes: an infrared sensor element 5 for detecting infrared rays; an FET 6 for performing impedance conversion for an output signal of the infrared sensor element 5 and outputting the signal; a package 2 which stores the infrared sensor element 5 and the FET 6 and has an opening 4 on one surface; and a package lid 3 which closes the opening 4 and has means for transmitting the infrared rays. The package 2 has, in at least a part of an end edge part 2c, a groove 7 which makes the inside and the outside of the package 2 communicate with each other and can be sealed by sealant, and the package lid 3 is joined to the end edge part 2c.

Description

  The present invention relates to a surface-mount type infrared sensor on which a sensor element for detecting infrared rays is mounted and a method for manufacturing the same.

  The infrared sensor includes an infrared sensor element that detects infrared rays. The pyroelectric element used as one of the infrared sensor elements has a feature that the surface charge fluctuates according to the temperature change caused by the irradiation of the infrared ray, and this feature is used to detect the infrared ray. Yes.

  Infrared sensors, when gas or moisture enters the internal space in which infrared sensor elements and other mounting parts are housed, deterioration of insulation resistance and corrosion progress, which may affect long-term reliability. Therefore, airtightness is required.

  When the infrared sensor is surface-mounted together with other electronic components on a substrate, it is generally passed through a reflow furnace at 200 ° C. or higher. Therefore, it is important to design the structure in consideration of an increase in internal pressure due to heating generated in the reflow process.

  4A and 4B are diagrams showing a conventional surface-mount type infrared sensor. FIG. 4A is a plan view, FIG. 4B is a cross-sectional view taken along the line GG, and FIG. It is line sectional drawing. The infrared sensor element 15 is mounted on the package 12 together with an FET (field effect transistor) 16 that performs impedance conversion on the output signal of the infrared sensor element 15. Further, the opening provided on the upper surface of the package 12 is covered with a package lid 13 made of an infrared transmitting filter or the like that transmits infrared rays, and sealed with an adhesive to form the infrared sensor 11. The infrared sensor 11 is provided with an external terminal 20 including an input / output terminal and a ground terminal, which is electrically connected to the infrared sensor element 15 and the FET 16, and can be surface-mounted. Such a surface-mount type infrared sensor has been proposed in, for example, Patent Document 1.

JP-A-4-158228

  In a conventional surface-mount type infrared sensor as shown in FIG. 4, the package 12 and the package lid 13 are joined using a thermosetting adhesive. In such a configuration, when heating is performed to cure the thermosetting adhesive, the inside of the infrared sensor 11 is highly airtight, and therefore the pressure inside the infrared sensor 11 is generated by gas or water vapor generated by heating. Rises. At this time, the adhesive fixing the package 12 and the package lid 13 oozes out to the outside, so that sufficient adhesive strength cannot be obtained, and the package lid 13 may be peeled off or displaced. There is. Also, during the reflow process of mounting the infrared sensor 11 on the surface, since the infrared sensor 11 is heated, the pressure inside the sensor rises in the same manner as described above, causing the package lid 13 to peel off or be displaced. There is a problem that the performance of elements inside the sensor may be affected.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a surface-mount type infrared sensor that realizes reliable bonding between a package and a package lid with an easy configuration and a method for manufacturing the same. It is to be.

  The present invention provides a package that houses an infrared sensor and a conversion member that outputs an output signal of the infrared sensor element by impedance conversion, and includes a bottom surface portion and a side surface portion that stands up around the bottom surface portion. A structure in which the opening is formed on the opposing surface, and a ventilation means capable of communicating and sealing the inside and the outside of the package is provided on at least a part of the edge of the side surface on which the opening is formed. It is. With this configuration, it is possible to release gas, water vapor, and the like generated inside the infrared sensor after the package lid is joined to the edge portion. Therefore, it is possible to prevent peeling and displacement of the package and the package lid due to an increase in pressure.

  That is, according to the present invention, an infrared sensor element that detects infrared rays, a conversion member that impedance-converts and outputs an output signal of the infrared sensor element, and the infrared sensor element and the conversion member are accommodated in an opening. And a package lid having a means for blocking the opening and transmitting infrared rays, the package comprising: a bottom surface portion; and a side surface portion standing around the bottom surface portion. The opening is formed on the surface facing the bottom surface, and the inside and outside of the package are communicated with at least a part of the edge on the side where the opening of the side surface is formed. An infrared sensor is provided, characterized in that a venting means capable of sealing is provided, and the package lid is joined to the edge portion.

  Further, according to the present invention, the infrared sensor is obtained, wherein the ventilation means is a groove in which the inner side and the outer side of the edge portion are connected.

  According to the present invention, in the infrared sensor, the ventilation means is exposed to the outside at least a part on the side where the opening is formed in a state where the package lid is joined. Is obtained.

  According to the invention, the package lid is made of a conductive material, the package is made of an insulating material, and at least a part of the ventilation means facing the package lid is conductive. A first conductive member is provided, and a second conductive member for electrically connecting the first conductive member and a portion of the infrared sensor element and the conversion member, which is a ground potential, is provided in the package. The above infrared sensor is obtained in which the ventilation means is sealed with a conductive sealant.

  Further, according to the present invention, the second conductive member is embedded in the package and is disposed over the package so as to surround the infrared sensor and the conversion member. Is obtained.

  According to the present invention, there is obtained the above infrared sensor, wherein the package is a wiring board, and the first conductive member and the second conductive member are formed by a wiring pattern.

  Further, according to the present invention, an infrared sensor element that detects infrared rays, a conversion member that impedance-converts an output signal of the infrared sensor element, and outputs the infrared sensor element and the conversion member. And a package lid having a means for closing the opening and transmitting infrared rays, wherein the package is provided with a bottom surface and standing around the bottom surface portion. A side surface is provided, the opening is formed on a surface facing the bottom surface, and a ventilation means for communicating the inside and the outside of the package is provided on an edge of the side on which the opening is formed. After the package lid is joined to the edge portion, the ventilation means is sealed with a sealant, and an infrared sensor manufacturing method is obtained.

  Further, according to the present invention, the package lid is made of a conductive material, the package is made of an insulating material, and at least a part of the ventilation means facing the package lid is made conductive. A first conductive member having a first conductive member is provided, and a second conductive member for electrically connecting the first conductive member to the infrared sensor element and a portion to be a ground potential of the conversion member is disposed in the package. The method for manufacturing the infrared sensor is obtained by sealing the ventilation means with a conductive sealant.

  According to the present invention, in the infrared sensor, the second conductive member is embedded in the package and disposed in the entire package so as to surround the infrared sensor and the conversion member. A manufacturing method is obtained.

  According to the present invention, even when heating is performed in a reflow process for surface mounting after bonding a package and a package lid, gas, water vapor, and the like generated inside the infrared sensor can be released. For this reason, it is possible to mitigate an increase in pressure inside the infrared sensor and prevent peeling and displacement of the package and the package lid. Further, the ventilation means is provided with a first conductive member, and a second conductive member for electrically connecting the first sensor member and the infrared sensor element and the conversion member to be a ground potential is provided. Is sealed with a conductive sealant, so that the package and the package lid are at a ground potential, and electromagnetic noise from the outside can be shielded at the same time.

  Therefore, according to the present invention, it is possible to provide a surface-mount type infrared sensor and a method for manufacturing the same that can realize reliable bonding between the package and the package lid with an easy configuration.

The figure which shows the infrared sensor of 1st embodiment of this invention. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line AA, and FIG. 1C is a cross-sectional view taken along line BB. The figure which shows the infrared sensor of 2nd embodiment of this invention. 2A is a plan view, FIG. 2B is a sectional view taken along the line CC, and FIG. 2C is a sectional view taken along the line DD. The figure which shows the infrared sensor of 3rd embodiment of this invention. 3A is a plan view, FIG. 3B is a cross-sectional view taken along line EE, and FIG. 2C is a cross-sectional view taken along line FF. The figure which shows the conventional surface mount type infrared sensor. 4A is a plan view, FIG. 4B is a cross-sectional view taken along the line GG, and FIG. 2C is a cross-sectional view taken along the line H-H.

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

(First embodiment)
1A and 1B are diagrams showing an infrared sensor according to a first embodiment of the present invention. FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line AA, and FIG. , BB line sectional view.

  The infrared sensor 1 of the present invention includes an infrared sensor element 5 that detects infrared rays, a FET 6 that is a conversion member that outputs an output signal of the infrared sensor element 5 by impedance conversion, and a package 2 that houses the infrared sensor element 5 and the FET 6. And a package lid 3 having means for transmitting infrared rays. The package 2 includes a bottom surface portion 2a and a side surface portion 2b erected around the bottom surface portion 2a, and an opening 4 is formed on a surface facing the bottom surface portion 2a. In addition, a groove 7 is formed in the end edge portion 2c on the side (opening surface) where the opening portion of the side surface portion 2b is formed as a ventilation means that allows the inside and outside of the package 2 to communicate and be sealed. Further, the package lid 3 is joined to the edge 2c.

  The groove 7 only needs to be formed by connecting the inner side and the outer side of the edge 2c, and the formation position and quantity are not limited. By forming the groove 7, the inside and outside of the infrared sensor 1 can be ventilated even when the package 2 and the package lid 3 are joined. After the reflow process in which the package 2 and the package lid 3 are joined and the surface mounting of the internal components such as the infrared sensor element 5 and the FET 6 is performed, and after each reflow process in which the surface mounting of the infrared sensor is performed, the groove 7 is sealed. It is possible to seal with an agent.

  In the present invention, by providing the groove 7 in the edge 2c of the package 2, it is very easy to seal the infrared sensor after surface mounting of the infrared sensor. For example, if the ventilation means is provided on the bottom of the package or provided on the side of the package, the timing of the sealing process of the ventilation means is obstructed by the surface mount board or other components mounted simultaneously with the infrared sensor. May be restricted, and the sealing process may be complicated. With the configuration of the present invention, since the sealing process can be performed at a timing that takes productivity into consideration, mass productivity and design freedom are also improved.

  The shape of the groove 7 is not particularly limited. In order to prevent the sealant from flowing into the inside or outside of the package 2 when the groove 7 is sealed, an inclination is provided so as to be lowered toward the center of the groove 7. It is also possible to provide a flow path for the sealant.

  In addition, it is preferable that the package lid 3 to be joined to the edge portion 2c is made smaller than the outer dimension of the opening surface of the package 2 and a part of the groove 7 is exposed to the opening surface side. With this configuration, the workability when injecting the sealant is remarkably improved and the manufacture becomes easy.

  The infrared sensor element 5 is installed in the package 2 in parallel or substantially in parallel with the opening surface serving as the light receiving surface. As the infrared sensor element 5, a pyroelectric element having a pair of electrodes formed on the front and back surfaces thereof is used, and the material thereof is a ferroelectric ceramic such as lead zirconate titanate or barium titanate, a single crystal such as lithium tantalate, An organic material such as polyvinylidene fluoride is used. It is possible to form a plurality of sets of electrodes on the pyroelectric element or to use a plurality of infrared sensor elements.

  In this embodiment, the FET 6 is used as a conversion member for impedance-converting the output signal of the infrared sensor element 5 and outputting it. Depending on the application, electronic components such as capacitors and resistors may be added in addition to the FET 6 to form a conversion member.

  Further, outside the bottom surface 2a of the package 2, an input / output terminal for inputting / outputting the infrared sensor 1 and an external terminal 10 including a ground terminal having a ground potential are provided. Input / output internal terminals and ground internal terminals electrically connected to the terminals 10 by wiring patterns or the like are provided. The infrared sensor element 5 and the FET 6 are configured to be electrically connected to an input / output internal terminal and a ground internal terminal with a conductive adhesive or the like. Here, the input / output internal terminal and the ground internal terminal may be directly provided on the package 2 and connected to the infrared sensor element 5 or the FET 6, or a circuit board may be separately prepared and provided on the circuit board for connection. Also good. Further, the arrangement location of the infrared sensor element 5 and the FET 6 is not particularly limited, but in consideration of miniaturization, a step is provided inside the package 2 and the infrared sensor element 5 and the FET 6 are stacked with a certain distance therebetween. It is preferable to arrange them as follows.

  The package lid 3 has a function of closing the opening of the package 2 and transmitting infrared light having a specific range of wavelengths into the package 2. As the package lid 3, a known material such as an infrared transmission filter or an infrared transmission lens made of silicon or germanium can be used, but it is particularly preferable to use a conductive material.

  The package 2 can be manufactured by a known wiring substrate such as a ceramic substrate or a glass epoxy substrate, resin molding, metal processing, or the like, but considering the mounting and wiring of the infrared sensor element 5 and the FET 6 disposed therein. It is particularly preferable to use a wiring board. Further, for bonding the package 2 and the package lid 3, an epoxy-based thermosetting adhesive can be used.

(Second embodiment)
FIG. 2 is a diagram showing an infrared sensor according to a second embodiment of the present invention. 2A is a plan view, FIG. 2B is a cross-sectional view taken along the line CC, and FIG. 2C is a cross-sectional view taken along the line DD. Since the basic configuration and the constituent materials of the present embodiment are the same as those of the first embodiment, only the portions different from the first embodiment will be described.

  In the present embodiment, a land of a wiring pattern is formed as a first conductive member in the groove 7 provided in the edge 2 c of the package 2, and the land formed in the groove 7 is provided on the inner surface of the package 2. It is the structure which electrically connected between the ground internal terminals with the wiring pattern 9 which is a 2nd electrically-conductive member. The shape of the wiring pattern 9 is not particularly limited, and wiring with through vias using a multilayer substrate can also be applied. Further, the land of the groove 7 and the package lid 3 bonded to the edge 2c are bonded by the conductive adhesive 8, and the groove 7 is sealed. With this configuration, it is possible to seal the infrared sensor 1 and at the same time have a function of shielding external electromagnetic noise.

(Third embodiment)
FIG. 3 is a diagram showing an infrared sensor according to a third embodiment of the present invention. 3A is a plan view, FIG. 3B is a cross-sectional view taken along line EE, and FIG. 3C is a cross-sectional view taken along line FF. Since the basic configuration and the constituent materials of the present embodiment are the same as those of the first embodiment, the differences from the first embodiment will be described.

  In the present embodiment, as in the second embodiment, a land of a wiring pattern is formed as a first conductive member in the groove 7 provided in the edge 2c of the package 2, and the groove 7 is formed in the groove 7. In this configuration, the wiring pattern 9 is electrically joined as a second conductive member between the land and the ground internal terminal provided on the inner surface of the package 2. Furthermore, in the present embodiment, a part of the wiring pattern 9 is embedded in the bottom surface portion 2a and the side surface portion 2b of the package 2, and is disposed on the entire package 2 so as to surround the infrared sensor element 5 and the FET 6. It becomes the composition. The wiring pattern 9 is preferably formed using a multilayer substrate provided with through vias.

  Further, as in the second embodiment, the land of the groove 7 and the package lid 3 bonded to the end edge 2c are bonded by the conductive adhesive 8 and the groove 7 is sealed. With this configuration, it is possible to seal the infrared sensor 1 and at the same time have a function of shielding external electromagnetic noise on the entire surface of the infrared sensor 1. In addition, since the package 2 can have insulating properties, a short circuit with the infrared sensor element 5 and the FET 6 disposed inside the infrared sensor 1 and a short circuit with an electronic component disposed outside the infrared sensor 1 are possible. It is possible to prevent defects and the like.

  The infrared sensor of the third embodiment of the present invention will be specifically described using examples.

  As the package, a ceramic multilayer substrate having a size of 5.0 mm × 5.0 mm × thickness 1.5 mm was used. An opening of 3.5 mm × 3.5 mm was formed on the upper surface of the package. In addition, the ceramic multilayer substrate was processed so that the level | step difference for supporting an infrared sensor element might be provided in the inside of a package. An input / output internal terminal and a ground internal terminal that are electrically connected to the infrared sensor element were formed on the surface of the step contacting the infrared sensor element. In addition, an input / output internal terminal and a ground internal terminal electrically connected to the FET were formed inside the bottom surface of the package. These input / output internal terminals and ground internal terminals were electrically connected to the input / output terminals and the ground terminals formed outside the bottom surface of the package by wiring patterns such as through vias. Here, in the ceramic multilayer substrate, a wiring pattern is formed on the entire surface (excluding the portion connected to the input / output terminals) on one layer located on the bottom surface portion of the package, and on the portion located on the side surface portion of the package. A plurality of through vias perpendicular to the bottom surface portion were formed so as to go around the side surface and connected to the ground terminal to obtain a ground potential.

  Two grooves having a width of 0.5 mm and a depth of 0.5 mm were formed at the edge of the package. A land of a wiring pattern was formed on the surface of the groove, and was electrically connected to the wiring pattern and the ground terminal formed in the package.

  Infrared sensor element uses a pyroelectric body made of lead zirconate titanate 3.0mm x 3.0mm x 0.1mm thick with electrodes formed on the steps formed inside the package did. The FET used was 1.5 mm × 1.5 mm × thickness 1 mm, and was arranged on the bottom of the package. Here, a conductive adhesive was applied in advance to the input / output internal terminal and the ground internal terminal formed inside the package, and the infrared sensor element and the FET were temporarily fixed.

  As the package lid, an infrared filter made of silicon having a size of 4.0 mm × 4.0 mm × thickness 0.5 mm was used and arranged at the edge of the package. Here, an epoxy-based thermosetting adhesive was applied in advance to a portion of the package edge to be joined with the package lid, and the package lid was temporarily fixed. At this time, the thermosetting adhesive was not applied to the portion where the groove was formed, and a ventilation means for communicating the inside and the outside of the package was formed.

  As a comparative example, a package in which no groove was formed in the edge portion was manufactured, and other configurations were manufactured in the same manner as in the example. In the comparative example, a groove is not formed at the end edge portion, so that the inside and outside of the package are not vented.

  50 samples of each of the example and the comparative example were manufactured, the infrared sensor element and the FET were surface-mounted, and the first reflow process for joining the package and the package lid was put into an infrared sensor. The reflow conditions were a peak temperature of 260 ° C. and 15 seconds.

  Then, it put into the 2nd reflow process supposing surface mounting of an infrared sensor. The reflow conditions were a peak temperature of 260 ° C. and 15 seconds.

  Thereafter, a conductive adhesive was injected into the groove formed in the edge of the package in the infrared sensor of the example, and was cured by heat. Thereby, the land of the wiring pattern formed on the surface of the groove and the package lid were electrically connected and the infrared sensor was sealed at the same time.

  The peeling and displacement of the package lid after the first reflow process and the second reflow process were visually confirmed in the examples and comparative examples. The results are shown in Table 1.

  As shown in Table 1, the embodiment of the present invention has a package lid after any of the first reflow process for surface mounting the infrared sensor element and the FET and the second reflow process for surface mounting the infrared sensor. No peeling or misalignment occurred.

  As described above, according to the present invention, it is possible to provide a surface-mount type infrared sensor that realizes reliable bonding between a package and a package lid with an easy configuration and a method for manufacturing the same. Furthermore, the electromagnetic noise shielding effect of the infrared sensor can be obtained at the same time.

DESCRIPTION OF SYMBOLS 1, 11 Infrared sensor 2, 12 Package 2a Bottom surface part 2b Side surface part 2c Edge part 3, 13 Package lid 4 Opening part 5, 15 Infrared sensor element 6, 16 FET
7 Groove 8 Conductive adhesive 9 Wiring pattern 10, 20 External terminal

That is, according to the present invention, an infrared sensor element that functions as a pyroelectric element for detecting infrared rays, a conversion member that impedance-converts an output signal of the infrared sensor element, and the infrared sensor element and the conversion member An infrared sensor comprising: a package housed and having an opening on one surface; and a package lid having a means for closing the opening and transmitting infrared rays, the package standing on a periphery of the bottom surface and the bottom surface. The opening is formed on a surface facing the bottom surface, and the inside and outside of the package are connected to at least a part of the edge of the side on which the opening is formed. communicating, sealable vent means are provided by a sealant, wherein the package lid the edge portion is joined, dew than partially the package lid of the ventilating means Infrared sensor is obtained, characterized by that.

Further, according to the present invention, an infrared sensor element that functions as a pyroelectric element that detects infrared light, a conversion member that impedance-converts an output signal of the infrared sensor element, and the infrared sensor element and the conversion member. A method for manufacturing an infrared sensor, comprising: a package housed and having an opening on one surface; and a package lid having a means for closing the opening and transmitting infrared rays, wherein the package includes a bottom surface portion and the bottom surface portion. A side portion standing up around the bottom surface, forming the opening in a surface facing the bottom portion, and communicating the inside and outside of the package to the edge portion of the side portion where the opening is formed ventilation means for providing said part of said venting means the package lid the edge portion joined while exposed from the package lid, after all the reflow step is completed, Method for manufacturing an infrared sensor, characterized in that sealing the serial ventilation means with a sealing agent is obtained.

Claims (9)

  An infrared sensor element for detecting infrared rays; a conversion member for impedance-converting and outputting an output signal of the infrared sensor element; a package containing the infrared sensor element and the conversion member and having an opening on one surface; and the opening An infrared sensor comprising a package lid having means for transmitting infrared rays, wherein the package includes a bottom surface portion and a side surface portion standing around the bottom surface portion, and faces the bottom surface portion. Ventilation means that forms the opening on the surface, communicates the inside and outside of the package with at least a part of the end edge on the side where the opening is formed, and can be sealed with a sealant And the package lid is joined to the end edge portion.   The infrared sensor according to claim 1, wherein the ventilation means is a groove in which the inner side and the outer side of the edge portion are connected.   3. The infrared sensor according to claim 1, wherein at least a part of the ventilation unit on the side where the opening is formed is exposed to the outside in a state where the package lid is joined. 4. .   The package lid is made of a conductive material, the package is made of an insulating material, and at least a part of the ventilation means facing the package lid is provided with a first conductive member having conductivity, The package is provided with a second conductive member that electrically connects the infrared sensor element and a portion of the conversion member that is a ground potential to the first conductive member, and the ventilation means has conductivity. It seals with the sealing agent which has, The infrared sensor as described in any one of Claims 1-3 characterized by the above-mentioned.   5. The second conductive member is embedded in the package, and is disposed on the entire package so as to surround the infrared sensor and the conversion member. 6. The infrared sensor described in 1.   6. The infrared ray according to claim 1, wherein the package is a wiring board, and the first conductive member and the second conductive member are formed of a wiring pattern. Sensor.   An infrared sensor element for detecting infrared rays; a conversion member for impedance-converting and outputting an output signal of the infrared sensor element; a package containing the infrared sensor element and the conversion member and having an opening on one surface; and the opening And a package lid having means for transmitting infrared rays, wherein the package includes a bottom surface portion and a side surface portion standing around the bottom surface portion, and the bottom surface portion The opening is formed on a surface opposite to the side, and a ventilation means is provided on the end edge of the side surface on the side where the opening is formed, and the package lid is provided on the end edge. A method for manufacturing an infrared sensor, wherein the ventilation means is sealed with a sealant after bonding.   The package lid is made of a conductive material, the package is made of an insulating material, and a conductive first conductive member is provided on at least a part of the ventilation means facing the package lid. A second conductive member for electrically connecting the first conductive member and a portion of the infrared sensor element and the conversion member, which is a ground potential, to the package, and the ventilation means is made conductive. Sealing with the sealing agent which has, The manufacturing method of the infrared sensor of Claim 7 characterized by the above-mentioned.   9. The infrared sensor according to claim 7, wherein the second conductive member is embedded in the package and disposed over the package so as to surround the infrared sensor and the conversion member. Production method.

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