Patent Application
20240328836
This application claims priority benefit of Japanese Patent Application No. JP 2023-049798 filed in the Japan Patent Office on Mar. 27, 2023. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety.
The present disclosure relates to a sensor module.
One example of a sensor module includes a sensor module including a pressure sensor proposed in PCT Patent Publication No. WO2022/080130. The pressure sensor is manufactured with use of a micro-electro-mechanical system (MEMS) technology applied to microfabrication of a semiconductor device. The pressure sensor is mounted on an electronic component that processes a signal detected by the pressure sensor. The electronic component and the pressure sensor are housed in a package. A cover member is attached to the package in such a manner as to cover the housed pressure sensor, etc.
The package housing the pressure sensor, etc., is installed on an installation board. A plurality of electrode pads are arranged on an installation surface of the package facing the installation board. The pressure sensor and the electronic component are electrically connected to the corresponding electrode pads. Meanwhile, circuit patterns are formed on the installation board. The plurality of electrode pads installed on the installation board are electrically connected to the corresponding circuit patterns.
An example of a sensor module according to an embodiment will be described. As illustrated in
The box-shaped package 3 includes a bottom surface portion 5 and a side surface portion 7. The package 3 (sensor module 1) has a square shape in plan view as viewed from an upper side. The package 3 includes a first plane portion 3a (one plane portion; one side), a second plane portion 3b, a third plane portion 3c (another plane portion; another side), and a fourth plane portion 3d that form the square shape of the package 3. Each of the first to fourth plane portions 3a to 3d includes a surface of the corresponding side surface portion 7 and a surface (end surface) of the bottom surface portion 5 flush with the surface. Note that the square shape is not intended to be a square shape in a strict geometric sense, and the square shape is intended to be a shape that can be recognized as a square shape at a glance. The square shape may also have a manufacturing error, for example.
The side surface portion 7 is formed upright with respect to the bottom surface portion 5. The package 3 has a ceramic layered structure obtained by layering and firing a plurality of green sheets. The bottom surface portion 5 is formed from, for example, three relatively thin ceramic layers. The side surface portion 7 is formed from, for example, three ceramic layers including relatively thick ceramic layers.
A thickness C1 of first to third ceramic layers (bottom surface portion 5) is, for example, approximately 180 μm. A thickness C2 of a fourth ceramic layer (lowermost layer of the side surface portion 7) is, for example, approximately 200 μm. A thickness C3 of a fifth ceramic layer (center layer of the side surface portion 7) is, for example, approximately 240 μm. The dimension in the height direction of an opening 9 described later is approximately 0.24 mm (240 μm). A thickness C4 of a sixth ceramic layer (uppermost layer of the side surface portion 7) is, for example, approximately 100 μm.
The sensor unit 11 is housed in the package 3. The sensor unit 11 includes a pressure sensor body 13 and an electronic component 15. The pressure sensor body 13 is manufactured with use of the MEMS technology. A thin plate diaphragm (not illustrated) that detects changes in pressure is formed on the pressure sensor body 13. The electronic component 15 has a function of processing an electrical signal detected by the pressure sensor body 13. The electronic component 15 includes an application specific integrated circuit (ASIC) element.
Electrode pads 25 are formed on the side surface portion 7 in the package 3. The pressure sensor body 13 and the electrode pads 25 are electrically connected by bonding wires 27. The bottom surface portion 5 in the package 3 includes a mount surface 5a and an installation surface 5b. The sensor unit 11 is mounted on the mount surface 5a through bumps 31. The cover member 21 is attached to cover the sensor unit 11. The cover member 21 is attached to the package 3 through a cover member bonding portion 19.
The opening 9 for allowing communication between the space inside the package 3 housing the sensor unit 11 and the outside of the package 3 is formed on the side surface portion 7 in the package 3. The opening 9 is positioned on the first plane portion 3a and formed at a position (height) facing the pressure sensor body 13 in the sensor unit 11. The opening 9 is formed in, for example, a relatively thick ceramic layer among the three ceramic layers included in the side surface portion 7.
The installation surface 5b in the bottom surface
portion 5 faces an installation board 41 (see
A plurality of installation terminals 29 are arranged on the installation surface 5b. The sensor unit 11 is electrically connected to the corresponding installation terminals 29 through the electrode pads 25 and the bonding wires 27. The sensor unit 11 is also electrically connected to the corresponding installation terminals 29 through the bumps 31. The installation terminals 29 include one installation terminal 29a and nine installation terminals 29b.
The installation terminal 29a serves as a positioning terminal (pin) for adjusting the position of the sensor module 1 with respect to the installation board 41 (see
The installation terminals 29 are formed in such a manner as to extend from the positions corresponding to the ends of the package 3 toward the inside of the installation surface 5b. One installation terminal 29a and one installation terminal 29b are arranged in such a manner as to extend from the end portion 6a toward the end portion 6b. Two installation terminals 29b are arranged in such a manner as to extend from the end portion 6b toward the end portion 6a. Three installation terminals 29b are arranged in such a manner as to extend from the end portion 6c toward the end portion 6d. Three installation terminals 29b are arranged in such a manner as to extend from the end portion 6d toward the end portion 6c.
As illustrated in
The opening 9 for allowing communication between the space inside the package 3 and the outside is formed on the side surface portion 7 (first plane portion 3a) of the package 3 in the sensor module 1. This can prevent foreign objects and any other objects from entering the space inside the package 3. This will be described in comparison with a sensor module according to a comparative example.
As illustrated in
The cover member 121 is attached to the package 103 through a cover member bonding member 119. An opening 109 for allowing communication between the space inside the package 103 housing the sensor unit 111 and the outside of the package 103 is formed on the cover member 121. The size of the opening 109 is, for example, 0.3 mmφ.
The sensor module 101 is installed on an installation board (not illustrated) and used. If a foreign object drifts in an upper part of the sensor module 101 in this case, the foreign object may easily enter the inside of the package 103 from the opening 109 formed on the cover member 121. If the foreign object enters the inside of the package 103 housing the sensor unit 111, the pressure sensing by the pressure sensor body 113 may be adversely affected.
In contrast to the sensor module 101 according to the comparative example, the opening 9 is formed on the side surface portion 7 (first plane portion 3a) of the package 3 in the sensor module 1 according to the embodiment. This can prevent a foreign object from entering the space inside the package 3 from the opening 9 formed on the side surface portion 7 of the package 3 when the foreign object drifts in an upper part of the installation board 41 (see
Another example of the plurality of installation terminals 29 arranged on the installation surface 5b in the bottom surface portion 5 of the package 3 will be described.
As illustrated in
One installation terminal 29c and one installation terminal 29d are arranged in such a manner as to extend from the end portion 6a toward the end portion 6b. Two installation terminals 29d are arranged in such a manner as to extend from the end portion 6b toward the end portion 6a. Three installation terminals 29d are arranged in such a manner as to extend from the end portion 6c toward the end portion 6d. Three installation terminals 29d are arranged in such a manner as to extend from the end portion 6d toward the end portion 6c. In this case, the end surfaces of the corresponding installation terminals 29 (installation terminal 29c, installation terminals 29d) are not exposed on the surfaces flush with the side surface portion 7 in the bottom surface portion 5 of the package 3 as illustrated in
The installation terminals 29 and the corresponding circuit patterns formed on the installation board 41 (see
Modes of mounting the sensor unit 11 on the package 3 (bottom surface portion 5) will next be described. As described above, the sensor unit 11 is electrically connected to the installation terminals 29 arranged on the installation surface 5b (bottom surface portion 5), through the bumps 31 located between the mount surface 5a (bottom surface portion 5) and the sensor unit 11.
An example of the structure of the bumps 31 includes bumps 31 formed by bumps 33 on the sensor unit side arranged in advance on the sensor unit 11.
In this case, the sensor unit 11 is arranged on the lower side, and the package 3 is arranged on the upper side. In this state, the sensor unit 11 and the package 3 are brought close to each other to form the bumps 31. A distance T1 (see
Another example of the structure of the bumps 31 includes composite bumps 31 in which the bumps 33 on the sensor unit side arranged in advance on the sensor unit 11 and bumps 35 on the installation surface side arranged in advance on the installation surface 5b are bonded.
More specifically, the height (position) of the pressure sensor body 13 (sensor unit 11) from the mount surface 5a (bottom surface portion 5) can be adjusted by the thickness of the bumps 31, and the height of the opening 9 with respect to the pressure sensor body 13 can be adjusted. Note that there is an interface between the bumps 33 on the sensor unit side and the bumps 35 on the installation surface side in the case of the composite bumps 31, and this distinguishes the structure of the composite bumps 31 from the structure of the bumps 31 in the case of the first example.
In the case of the composite bumps 31, the same kind of metal can be bonded by using the same metal, such as gold (Au), for the bumps 33 on the sensor unit side and the bumps 35 on the installation surface side. This can further increase the bond strength, and poor bonding can be reduced.
The ceramic layered structure is described as an example of the package 3 as a box-shaped structure that houses the sensor unit 11 in the sensor module. The package 3 is not limited to the ceramic layered structure, and the package 3 may be, for example, a box-shaped metal. In addition, the values of dimensions and the numbers of layers described in the embodiment are examples, and they are not limited to the described numerical values.
Note that the sensor module described in the embodiment can be combined in various ways as necessary.
The embodiment disclosed this time is illustrative, and the embodiment is not limited to this. The present disclosure is illustrated by the claims rather than the scope described above, and all changes within the meaning and range of equivalents of the claims are intended to be included in the present disclosure.
The present disclosure includes the following modes.
A sensor module including:
The sensor module according to supplement 1, in which
The sensor module according to supplement 2, in which
The sensor module according to supplement 3, in which
The sensor module according to any one of supplements 2 through 4, further including:
The sensor module according to any one of supplements 2 through 5, in which
The sensor module according to any one of supplements 2 through 5, in which
The sensor module according to any one of supplements 1 through 7, in which
The sensor module according to any one of supplements 1 through 8, in which
According to the sensor module of an embodiment of the present disclosure, the opening for allowing communication between the space inside the box-shaped structure housing the sensor unit and the outside is formed on the side surface portion in the box-shaped structure. This can prevent the foreign object from entering the space inside the box-shaped structure.
The present disclosure is effectively used for a sensor module with a sensor unit including a pressure sensor body.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-049798 | Mar 2023 | JP | national |
