WO2024058037A1

WO2024058037A1 - Infrared sensor module

Info

Publication number: WO2024058037A1
Application number: PCT/JP2023/032633
Authority: WO
Inventors: 真一郎番場
Original assignee: 株式会社村田製作所
Priority date: 2022-09-13
Filing date: 2023-09-07
Publication date: 2024-03-21

Abstract

An infrared sensor module (101) comprises: a first substrate (51) that has a first surface (51a); a pyroelectric element (3) that is mounted on the first surface (51a); an annular member (4) that is connected to the first surface (51a) so as to surround the pyroelectric element (3); and a second substrate (52) that is disposed so as to be parallel to the first substrate (51) and at least partially overlap the first substrate (51). The second substrate (52) has an opening (52e) in a region that includes a projection region of the pyroelectric element (3). The annular member (4) is connected to the second substrate (52) while being disposed so as to surround the opening (52e). An infrared transmission filter (7) is attached to the second substrate (52) so as to close the opening (52e). A sealing resin (6) is disposed so as to seal a region of the surface of the second substrate (52) on the first substrate (51) side outward of the annular member (4).

Description

infrared sensor module

The present invention relates to an infrared sensor module.

An infrared sensor equipped with a metal shield case is described in Patent No. 5465288 (Patent Document 1).

Patent No. 5465288

In recent years, with the spread of IoT, infrared sensors are increasingly being adopted in home appliances, etc., and there is a need for infrared sensor modules to be smaller and lower in profile. Furthermore, as an infrared sensor module, there is a demand for a module that can be handled as a surface mount component, rather than a module that connects with pins on the back side.

Therefore, an object of the present invention is to provide an infrared sensor module that is suitable for miniaturization and low profile and can be handled as a surface-mounted component.

In order to achieve the above object, an infrared sensor module based on the present invention includes a first substrate having a first surface, a pyroelectric element mounted on the first surface, and a pyroelectric element mounted on the first surface so as to surround the pyroelectric element. The device includes an annular member connected to the surface, and a second substrate disposed parallel to the first substrate so as to at least partially overlap the first substrate. The second substrate has an opening in a region including the projection region of the pyroelectric element. The annular member is connected to the second substrate while being arranged so as to surround the opening. An infrared transmission filter is attached to the second substrate so as to close the opening. A sealing resin is disposed to seal a region of the second substrate on the first substrate side that is outside the annular member.

According to the present invention, it is possible to realize an infrared sensor module that is suitable for downsizing and height reduction and can be handled as a surface-mounted component.

FIG. 1 is a perspective view of an infrared sensor module in Embodiment 1 based on the present invention. 1 is a plan view of an infrared sensor module in Embodiment 1 based on the present invention. FIG. 3 is a sectional view taken along the line III-III in FIG. 2. FIG. It is a partial plan view of the 1st surface of the 1st board|substrate with which the infrared sensor module in Embodiment 1 based on this invention is equipped. FIG. 3 is a cross-sectional view of an infrared sensor module according to a second embodiment of the present invention.

The dimensional ratios shown in the drawings do not necessarily faithfully represent the reality, and the dimensional ratios may be exaggerated for convenience of explanation. In the following description, references to the concepts of top or bottom do not necessarily mean absolute top or bottom, but may mean relative top or bottom within the illustrated posture. .

(Embodiment 1)
An infrared sensor module according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. A perspective view of an infrared sensor module 101 in this embodiment is shown in FIG. 1, and a plan view is shown in FIG. FIG. 3 shows a sectional view taken along the line III--III in FIG. 2.

The infrared sensor module 101 includes a first substrate 51 having a first surface 51a, a pyroelectric element 3 mounted on the first surface 51a, and an annular member connected to the first surface 51a so as to surround the pyroelectric element 3. 4, and a second substrate 52 disposed parallel to the first substrate 51 so as to at least partially overlap the first substrate 51. The second substrate 52 has an opening 52e in a region including the projection region of the pyroelectric element 3. The annular member 4 is connected to the second substrate 52 while being arranged so as to surround the opening 52e. An infrared transmission filter 7 is attached to the second substrate 52 so as to close the opening 52e. The sealing resin 6 is arranged so as to seal a region of the surface of the second substrate 52 on the first substrate 51 side outside the annular member 4 .

A sealed space 1 is formed between the infrared transmission filter 7 and the first substrate 51. Space 1 is surrounded by first substrate 51 , second substrate 52 , annular member 4 , and infrared transmission filter 7 . The pyroelectric element 3 is arranged within the space 1. The pyroelectric element 3 is mounted on the first surface 51a via the electrode 13. A gap is provided between the pyroelectric element 3 and the first surface 51a.

FIG. 4 shows the central part of the first surface 51a. The annular member 4 and the connection conductor 8 are arranged at the center of the first surface 51a. An electrode 13 for electrical connection with the pyroelectric element 3 is actually arranged inside the annular member 4 on the first surface 51a, but the electrode 13 is not shown in FIG. . As shown in FIG. 3, the first substrate 51 has a second surface 51b as a surface opposite to the first surface 51a. The sealing resin 6 covers the second surface 51b. Terminals 9 are connected to the surface of the second substrate 52 on the first substrate 51 side.

In this embodiment, it is possible to realize an infrared sensor module that is suitable for miniaturization and low profile and can be handled as a surface-mounted component. Furthermore, in this embodiment, it is possible to realize a configuration in which the pyroelectric element is mounted in a closed space without requiring a metal case.

Preferably, this embodiment further includes the following configuration. As shown in FIG. 3, the electronic component 15 is mounted on a region of the surface of the second substrate 52 on the first substrate 51 side that is outside the annular member 4. A connection conductor 8 that electrically connects the first substrate 51 and the second substrate 52 is arranged in a region outside the annular member 4 on the surface of the second substrate 52 on the first substrate 51 side. Electronic component 15 and connection conductor 8 are sealed with sealing resin 6. By employing this configuration, the electronic components 15 and the like can be protected by the sealing resin 6.

Preferably, this embodiment further includes the following configuration. A terminal 9 is arranged in a region outside the annular member 4 on the surface of the second substrate 52 on the first substrate 51 side so as to be connected to the second substrate 52. 2 is exposed on the side far from the substrate 52. By employing this configuration, electrical connection between the second substrate 52 and the outside can be made smoothly. The end face of the terminal 9 is on the same plane as the surface of the sealing resin 6. Since electrical connections can be made using the terminals 9, the infrared sensor module 101 can be surface mounted.

Note that the annular member 4 is preferably formed of solder. By employing this configuration, it becomes easy to form the annular member 4 at the same time in the process of attaching solder to other electrodes.

However, if the annular member 4 is formed only of solder, the amount of solder will be large, so there is a risk that structural defects such as voids will occur inside the annular member 4. If there is a structural defect such as a void inside the annular member 4, there is a concern that the resin may enter the space 1 when filled with resin to form the sealing resin 6. In order to avoid such problems, the annular member 4 may be formed mainly of a metal other than solder. The annular member 4 may be made of metal such as Cu. By doing so, the amount of solder used for bonding between the first substrate 51 and the second substrate 52 can be reduced, and the risk of occurrence of structural defects such as voids can be reduced.

Note that the first substrate 51 and the second substrate 52 may be a glass epoxy substrate, a ceramic multilayer substrate, or a resin multilayer substrate. The resin multilayer substrate referred to herein may be formed of a liquid crystal polymer resin. The first substrate 51 and the second substrate 52 may be semiconductor substrates mainly made of Si or the like. The material of the first substrate 51 and the material of the second substrate 52 may be the same or different.

Si has high transmittance for infrared wavelengths that can be detected by a pyroelectric sensor. Therefore, Si can be used as the material for the infrared transmission filter 7. When the material of the infrared transmission filter 7 is Si and a Si substrate is used as the second substrate 52, the second substrate 52 and the infrared transmission filter 7 can be integrally formed. When the second substrate 52 and the infrared transmitting filter 7 are integrally formed, it is necessary to make the infrared transmitting filter 7 thinner than the other parts, but such a structure cannot be achieved by Si etching such as anisotropic etching. It can be formed using technology.

(Embodiment 2)
Referring to FIG. 5, an infrared sensor module according to a second embodiment of the present invention will be described. FIG. 5 shows a cross-sectional view of the infrared sensor module 102 in this embodiment.

In the infrared sensor module 102, the first substrate 51 has a second surface 51b as a surface opposite to the first surface 51a. Electronic components 15 are mounted on the second surface 51b. The electronic component 15 is sealed with a sealing resin 6.

In this embodiment, since the electronic component 15 is mounted on the second surface 51b of the first substrate 51, the area occupied by the infrared sensor module 102 can be reduced. In other words, miniaturization can be achieved.

Preferably, this embodiment further includes the following configuration. Terminals 9 are arranged on the second surface 51b so as to be connected to the first substrate 51. The terminal 9 is exposed on the surface of the sealing resin 6 on the side far from the first substrate 51. By adopting this configuration, since the terminal 9 is also arranged on the second surface 51b, the area occupied by the infrared sensor module 102 can be further reduced. That is, further miniaturization can be achieved.

Note that a plurality of the above embodiments may be appropriately combined and adopted.
Note that the above-described embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims, and includes meanings equivalent to the claims and all changes within the range.

1 Space, 3 Pyroelectric element, 4 Annular member, 6 Sealing resin, 7 Infrared transmission filter, 8 Connection conductor, 9 Terminal, 12 Wiring, 13 Electrode, 15 Electronic component, 51 First substrate, 51a First surface, 51b Second surface, 52 second substrate, 52e opening, 101, 102 infrared sensor module.

Claims

a first substrate having a first surface;
a pyroelectric element mounted on the first surface;
an annular member connected to the first surface so as to surround the pyroelectric element;
a second substrate disposed parallel to the first substrate so as to at least partially overlap the first substrate;
The second substrate has an opening in a region including the projection area of the pyroelectric element, and the annular member is connected to the second substrate while being arranged so as to surround the opening.
an infrared transmission filter is attached to the second substrate so as to close the opening;
An infrared sensor module, wherein a sealing resin is arranged so as to seal an area outside the annular member on a surface of the second substrate on the first substrate side.
An electronic component is mounted on a region of the second board on the first board side that is outside the annular member, and an electronic component is mounted on a region of the second board on the first board side that is outside the annular member. A connecting conductor electrically connecting the first substrate and the second substrate is arranged in the region, and the electronic component and the connecting conductor are sealed with the sealing resin. Infrared sensor module described in.
A terminal is arranged in a region outside the annular member of the surface of the second substrate on the first substrate side so as to be connected to the second substrate, and the terminal is connected to the second substrate of the sealing resin. 3. The infrared sensor module according to claim 2, wherein the infrared sensor module is exposed on a side far from the second substrate.
The first substrate has a second surface opposite to the first surface, and an electronic component is mounted on the second surface, and the electronic component is sealed with the sealing resin. The infrared sensor module according to claim 1.
Terminals are arranged on the second surface so as to be connected to the first substrate, and the terminals are exposed on a surface of the sealing resin on a side far from the first substrate. 4. The infrared sensor module according to 4.
The infrared sensor module according to any one of claims 1 to 5, wherein the annular member is made of solder.
The infrared sensor module according to any one of claims 1 to 5, wherein the annular member is formed mainly of a metal other than solder.