This application claims priority to Japanese Patent Application No. 2020-199385 filed Dec. 1, 2020, the contents of which are hereby incorporated herein by reference in their entirety.
The present invention relates to an electronic device including a microphone module.
An electronic device like a laptop PC includes a microphone module (for example, refer to Japanese Unexamined Patent Application Publication No. 2013-165409).
As described in the above-described Japanese Unexamined Patent Application Publication No. 2013-165409, it is common that a conventional microphone module is fixed to a chassis using a screw.
However, it may be difficult to secure a space for fastening a screw since the electronic device like a laptop PC is rapidly becoming thinner and a width of a bezel is rapidly becoming reduced.
Then, the microphone module can be fixed to the chassis by a double-sided tape. However, a double-sided tape that has a strong adhesive power enough to ensure high air-tightness generally does not have electrical conductivity. Thus, in the method of fixing the microphone module by the double-sided tape, securing frame ground becomes an issue.
One or more embodiments provide an electronic device in which a microphone can be installed even in a reduced space.
An electronic device according to one or more embodiments is an electronic device including a chassis, a microphone hole penetrating an outer wall of the chassis and communicating the inside and outside of the chassis, and a microphone module provided in the chassis and disposed so as to face the microphone hole, in which the microphone module has a microphone configured to obtain sound information outside the chassis through the microphone hole, a flexible substrate laminated on a back surface of the microphone and mounted with the microphone, a metallic plate laminated on a back surface of the flexible substrate, and a sound hole opened in the back surface of the microphone and penetrating the flexible substrate and the metallic plate, and the electronic device further includes a double-sided tape fastened to a first region, surrounding the sound hole, of a back surface of the metallic plate, and to an inner surface of the chassis, and configured to fix the microphone module to the chassis, and a conductive member configured to electrically connect a second region, except the first region, of the metallic plate and the inner surface of the chassis.
An electronic device according to one or more embodiments includes a chassis, a microphone hole penetrating an outer wall of the chassis and communicating the inside and outside of the chassis, and a microphone module provided in the chassis and disposed so as to face the microphone hole, in which the microphone module has a microphone configured to obtain sound information outside the chassis through the microphone hole, a flexible substrate laminated on a back surface of the microphone and mounted with the microphone, a metallic plate laminated on a back surface of the flexible substrate, and a sound hole opened in the back surface of the microphone and penetrating the flexible substrate and the metallic plate, and the electronic device further includes a double-sided tape fastened to a first region, surrounding the sound hole, of a back surface of the metallic plate, and to an inner surface of the chassis, and configured to fix the microphone module to the chassis, and a conductive member installed between a second region, except the first region, of the back surface of the metallic plate, and the inner surface of the chassis, and configured to electrically connect the second region and the inner surface of the chassis.
According to one or more embodiments, it becomes possible to install a microphone even in a reduced space.
Hereinafter, embodiments of the present invention are described in detail with reference to the attached drawings.
Hereinafter, the electronic device 10 is described, based on a state where surface normal directions of the chassis 12 and 14 are orthogonal (at 90 degrees) to each other, with the direction toward a user using the keyboard 20 while visually recognizing a display surface 18a of the display 18 being referred to as front, the direction away from the user being referred to as rear, the width direction of the electronic device 10 being referred to as right and left, the top-and-bottom direction thereof being referred to as top and bottom. These respective directions are for convenience of description and actual directions vary accordingly depending on a posture of the electronic device 10 or an angle between the chassis 12 and 14.
The second chassis 14 is a flat box body. Various electronic components such as a motherboard mounted with a CPU etc., a battery device, a memory, and an antenna device, are stored within the second chassis 14. The keyboard 20 and the touchpad 21 are mounted so as to face a top surface 14a of the second chassis 14.
The first chassis 12 is a flat box body that is thinner than the second chassis 14. The display 18 has a display surface 18a that faces a front surface 12a of the first chassis 12. The first chassis 12 has a cover member 24 that forms a rear surface 12b, and a bezel member 26 that forms a peripheral edge part of the front surface 12a. Top, bottom, right, and left side surfaces 12c of the first chassis 12 are formed by vertical walls 32 raised from four peripheral edge parts of the cover member 24 (refer to
As illustrated in
The camera 28 is attached to the inner surface 12d of the first chassis 12. The camera 28 faces outside of the first chassis 12 through a camera hole 28a (refer to
The microphone module 30 is attached to the inner surface 12d of the first chassis 12. For example, four microphone modules 30 are installed so as to be arranged right and left. Each microphone module 30 obtains sound information outside the first chassis 12 through a microphone hole 30a formed on the side surface 12c on a top side of the first chassis 12 (refer to
Next, a configuration of the microphone module 30 is described.
As illustrated in
Each microphone module 30 is mounted on a flexible substrate 34 (FPC: Flexible Printed Circuits). The flexible substrate 34 extends between the inner surface 12d of the first chassis 12 and a back surface of the display 18 from the top to the bottom, and is connected to the motherboard etc. in the second chassis 14 from the bottom edge part of the first chassis 12 through the rear edge part of the second chassis 14. Each pair of the microphone modules 30 may be mounted on a different flexible substrate, for example. In addition, each microphone module 30 may be mounted on a separate flexible substrate. In the first embodiment, the camera 28 is also connected to the flexible substrate 34.
As illustrated in
The microphone 36 is, for example, a MEMS microphone in which a MEMS chip 36a having a vibrating membrane and IC chips 36b are shielded by a polymer cover 37. The sound hole 40 is opened in a back surface 36c of the microphone 36 (MEMS chip 36a). The flexible substrate 34 is laminated on the back surface 36c of the microphone 36. That is, a front surface 34a of the flexible substrate 34 becomes a surface on which the microphone 36 is mounted. It is to be noted that, in each drawing following
The metallic plate 38 is a thin plate that is made of a conductive metal such as stainless steel (SUS), aluminum, and copper. The metallic plate 38 is laminated on a back surface 34b of the flexible substrate 34. The metallic plate has a width dimension in the top-and-bottom direction slightly larger than the microphone 36 and a width dimension in the right-and-left direction larger to a certain extent than the microphone 36 and is formed into a substantially rectangular shape as a whole. Arc-shaped cutout parts 38a are formed at both right and left ends of the metallic plate 38. The cutout part 38a functions as a positioning part into which a positioning pin 42 raised from the inner surface 12d is fitted. The cutout part 38a and the positioning pin 42 may be omitted.
The flexible substrate 34 has a microphone-mounting part 34c that covers substantially the entire surface of a front surface 38b of the metallic plate 38 and a branch line part 34d that extends from the microphone-mounting part 34c toward the bottom. The branch line parts 34d of the respective microphone modules 30 gather at a main line part 34e to be routed to the second chassis 14 (refer to
The sound hole 40 is opened in the back surface 36c of the microphone 36 (MEMS chip 36a) and penetrates the flexible substrate 34 and the metallic plate 38. The sound hole 40 further penetrates a double-sided tape 50 as mentioned below and is communication with the microphone hole 30a of the first chassis 12. The sound hole 40 is a sound input part for the microphone module 30 and is communication with a vibrating membrane within the microphone 36.
Next, a structure for attaching the microphone module 30 to the first chassis 12 is described.
As illustrated in
It is to be noted that in the first chassis 12 as illustrated in
The double-sided tape 50 is an adhesive member for fixing the microphone module 30 to the inner surface 12d. The double-sided tape 50 fixes the back surface 38c of the metallic plate 38 and the inner surface 12d of the first chassis 12. The sound hole 40 also penetrates the double-sided tape 50. In other words, a through-hole in communication with the sound hole 40 is formed in the double-sided tape 50.
As illustrated in
The double-sided tape 50 must strongly fix the microphone module 30 to the inner surface 12d and ensure air-tightness of the sound hole 40. Currently, for the double-sided tape 50, only ones made of insulating materials are available on the market. The double-sided tape 50 according to the first embodiment may include, for example, VHB tape (registered trademark) from 3M Company.
The conductive double-sided tape 52 is a conductive member for grounding (frame-grounding) the microphone module 30 to the first chassis 12. The conductive double-sided tape 52 is fastened to the back surface 38c of the metallic plate 38 and the inner surface 12d of the first chassis 12.
As illustrated in
The conductive double-sided tape 52 must electrically connect the metallic plate 38 and the metal-deposited layer 54. The conductive double-sided tape 52 according to the first embodiment has a configuration, for example, in which adhesive layers filled with conductive fillers (for example, nickel fillers) are provided on both sides of a conductive base material (fabric).
For such a conductive double-sided tape 52, when the adhesive layers on both sides of the base material are not in a state of being sufficiently compressed, the conductive fillers filled in the respective adhesive layers are not sufficiently brought into contact with each other and a desired electrical conductivity cannot be obtained in the thickness direction. Then, as illustrated in
Therefore, when the microphone module 30 is fixed to the inner surface 12d of the first chassis 12, it presses the double-sided tape 50 and the conductive double-sided tape 52 against the surface of the metal-deposited layer 54 (inner surface 12d) while compressing them. Then, when the double-sided tape 50 is sufficiently compressed and the microphone module 30 is fixed to the inner surface 12d, the conductive double-sided tape 52 is compressed more by at least the thickness t. As a result, the conductive fillers of the respective adhesive layers are sufficiently brought into contact with each other, and the conductive double-sided tape 52 electrically connects the metallic plate 38 and the first chassis 12 with a desired electrical conductivity. The thickness of the conductive double-sided tape 52 may be set to, for example, more than 100% and less than or equal to 110% of the thickness of the double-sided tape. This is because too great thickness t would instead cause a decrease in adhesive power of the double-sided tape 50. It is to be noted that since a thickness ratio of the conductive double-sided tape 52 to the double-sided tape 50 also differs depending on the thickness of the double-sided tape 50 or a material of the conductive filler, it can be set to an optimum value according to each specification.
The configuration example as illustrated in
The conductive double-sided tape 58 may be a double-sided tape that has a characteristic the same as or similar to the above-described conductive double-sided tape 52 except that a thickness relationship relative to the double-sided tape 50 is different. As is clear from
The metallic sheet 56 is stuck onto the inner surface of the cover member 24 and its surface forms the inner surface 12d of the first chassis 12. The microphone module 30 is therefore fixed to a surface of the metallic sheet 56. The metallic sheet 56 is a thin sheet that is made of metal such as aluminum and copper.
A portion 56a (portion overlapping the first region R1 in plan view) to which the double-sided tape 50 is fixed, of the metallic sheet 56, has a back surface 56b that is stuck to the inner surface of the cover member 24 with a sticky agent or an adhesive. A portion 56c (portion overlapping the second region R2 in plan view) that overlaps the conductive double-sided tape 58, of the metallic sheet 56, has a non-adhesive region 56d where no adhesive or sticky agent is provided on the back surface 56b, and the non-adhesive region 56d is not stuck onto the inner surface 12d.
Therefore, when the microphone module 30 of the configuration example as illustrated in
As a result, since the conductive fillers in the respective adhesive layers are sufficiently brought into contact with each other, the conductive double-sided tape 58 is fixed to the metallic sheet 56 with a desired electrical conductivity, and the metallic plate 38 and the first chassis are electrically connected. The thickness of the conductive double-sided tape 58 may be set to, for example, less than 100% and more than or equal to 80% of the thickness of the double-sided tape. This is because if the conductive double-sided tape 58 is much thinner than the double-sided tape 50, the conductive double-sided tape 58 could instead not be sufficiently compressed and a desired electrical conductivity could not be obtained. It is to be noted that since a thickness ratio of the conductive double-sided tape to the double-sided tape 50 differs depending on the thickness of the double-sided tape 50 or a material of the conductive filler, it can be set to an optimum value according to each specification.
A configuration example as illustrated in
The metallic sheet 60 is a conductive member for electrically connecting the second region R2 of the back surface 38c of the metallic plate 38 and the inner surface 12d of the first chassis 12 (metal-deposited layer 54). The metallic sheet 60 is a thin sheet that is made of metal such as aluminum and copper. The metallic sheet 60 is installed, for example, in a state of being folded into a U-shape, on its side between the back surface 38c and the inner surface 12d. One end part (first end part 60a) of the U-shape of the metallic sheet 60 is fastened to the back surface 38c of the metallic plate 38 using an adhesive or a sticky agent. The other end part (second end part 60b) of the U-shape of the metallic sheet 60 is fastened to the inner surface 12d of the first chassis 12 (metal-deposited layer 54) using an adhesive or a sticky agent.
The metallic sheet 60 may be, for example, bent in a staircase shape without being folded in the U-shape, to be fixed to the back surface 38c and the inner surface 12d. However, since the first end part 60a and the second end part 60b are arranged in the right-and-left direction in this configuration, a right-and-left directional width of the microphone module 30 must be enlarged when the end parts 60a and 60b are intended to be fixed to the surfaces 38c and 12d with a sufficient contact area. In this regard, by folding the metallic sheet 60 into the U-shape as described above, the end parts 60a and 60b can be fixed to the surfaces 38c and 12d with a sufficient contact area, although its installation area is minimized in plan view. It is to be noted that also when the microphone module 30 of the configuration example as illustrated in
The microphone module 30A as illustrated in
In the microphone module 30 as illustrated in
Also in the microphone module 30A, the double-sided tape 50 must surround the periphery of the sound hole 40 within a predetermined radius region. This is to ensure the air-tightness of the microphone 36. Such a microphone module 30A may be used in combination with the configuration examples as illustrated in
As illustrated in
Next, a configuration of the microphone module 30B is described.
As illustrated in
A microphone 36, flexible substrate 34, and sound hole that constitute the microphone module 30B have configurations the same as or similar to those of the microphone 36, flexible substrate 34, and sound hole 40 that constitute the above-described microphone module 30 (30A). Although illustration is omitted in
In a configuration example as illustrated in
A basic structure of the metallic plate 62 may be the same as or similar to that of the above-described metallic plate 38. That is, the metallic plate 62 is made of a conductive metal such as stainless steel, and is laminated on a back surface 34b of the flexible substrate 34. The metallic plate 62 has a width dimension in the top-and-bottom direction the same as or similar to that of the above-described metallic plate 38 but has a width dimension in the right-and-left direction significantly larger than that of the above-described metallic plate 38 (refer to
As illustrated in
Next, a structure for attaching the microphone module 30B to the first chassis 12A is described.
As illustrated in
As illustrated in
The support bridge 12f is a part that supports the projecting part 62b of the metallic plate 62. The support bridge 12f is, for example, formed into a substantially T shape in plan view. The support bridge 12f protrudes from one of right and left ends of the microphone stand 12e in one of right and left directions. A height of the support bridge 12f is the same as that of the microphone stand 12e. The projecting part 62b abuts against a surface of the support bridge 12f across the double-sided tape 64. With this, the projecting part 62b is positioned at the same height position as the substrate fixing part 62a and stabilized. The support bridge 12f may be replaced by extension of the microphone stand 12e. The double-sided tape 64 on the back surface 38c of the projecting part 62b may be omitted by forming the support bridge 12f to be higher by the thickness of the double-sided tape 64 than the microphone stand 12e.
As illustrated in
The metallic sheet 66 has an adhesive tape structure in which an adhesive is provided on its back surface 66a. As illustrated in
Thus, the sticking part 66c is connected to the second region R2, except the first region R1, of the metallic plate 62. This second region R2 is a region that does not cross the sound hole 40, and includes, for example, both surfaces 38b and 38c of the projecting part 62b of the metallic plate 62. In the second embodiment, a configuration in which the sticking part 66c is connected to the second region R2 on the front surface 38b side, is illustrated as an example. The sticking part 66c may be connected to the second region R2 on the back surface 38c side (refer to the sticking part 66c as indicated by a dashed-two dotted line in
One example of an attaching method of the microphone module 30B is described. The first chassis 12A is in a state as illustrated in
As described above, the electronic devices 10 and 10A according to the above-described embodiments include the double-sided tapes 50 and 64 that are fastened to the first region R1, surrounding the sound hole 40, of the back surface 38c of the metallic plates 38 and 62 constituting the microphone modules 30 (30A) and 30B and to the inner surface 12d of the first chassis 12, and fix the microphone modules (30A) and 30B to the first chassis 12 and 12A. Further, the electronic devices 10 and 10A include the conductive member (conductive double-sided tapes 52, 58, metallic sheet 60, or metallic sheet 66) that electrically connects the second region R2, except the first region R1, of the metallic plates 38 and 62 and the inner surface 12d of the first chassis 12 and 12A.
Therefore, according to the electronic devices 10 and 10A, it is possible to ensure high air-tightness by fixing the microphone modules 30 (30A) and 30B to the inner surface 12d with high adhesive power by the double-sided tapes 50 and surrounding the sound hole 40. In addition, the microphone modules 30, 30A, and 30B eliminate the need for a mounting screw and a space for fastening it. Thus, the microphone modules 30, 30A, and 30B can be installed in a reduced space, and they can be surely installed in, for example, a narrow bezel space between the outer peripheral end surface 18b of the display 18 and the vertical wall 32. Furthermore, the microphone modules 30, 30A, and 30B can also surely secure the frame ground by the conductive member (conductive double-sided tapes 52, 58, metallic sheet 60, or metallic sheet 66).
The conductive member (conductive double-sided tape 52 etc.) for frame ground of the microphone module 30 (30A) according to the first embodiment is installed at a position sandwiched between the back surface 38c of the metallic plate 38 and the inner surface 12d of the first chassis 12. Thus, an outline area of the microphone module 30 (30A) in planar view can be minimized while the frame ground is surely secured, and space-saving, in particular, in the right-and-left direction is possible. As a result, while the right-and-left directional width of the microphone module 30 (30A) is configured to be, for example, substantially the same as that of the microphone element (microphone 36) (refer to FIG. 8A and
On the other hand, the conductive member (metallic sheet 66) for frame ground of the microphone module 30B according to the second embodiment is installed across the projecting part 62b resulting from extending the metallic plate 62 and inner surface 12d of the first chassis 12. The dimension of the microphone module 30B in the right-and-left direction is larger by the projecting part 62b than that of the above-described microphone modules 30 and 30A. However, the microphone module 30B is configured to stick the metallic sheet 66 onto the projecting part 62b protruded and exposed from the flexible substrate 34. Therefore, in the microphone module 30B, the conductive member (metallic sheet 66) does not stretch between the back surface 38c of the metallic plate 62 and the inner surface 12d of the first chassis 12A, unlike in the case of the microphone modules 30 and 30A according to the first embodiment. Thus, the microphone module 30B makes control of the thickness between the double-sided tape 50 and the conductive double-sided tape 52 taken in the microphone modules 30 and 30A unnecessary. That is, the microphone module 30B does not cause degradation in air-tightness due to variation in thickness of the conductive double-sided tape 52. Thus, the microphone module 30B is easy to manufacture and mount and can reduce manufacturing cost and cost of mounting work. In addition, the microphone module 30B eliminates the need for cost of forming the metal-deposited layer 54 since the metallic sheet 66 stuck to the inner surface 12d is directly stuck to the metallic plate 62. The microphone module 30B also has an advantage of easily securing a large adhesive area of the double-sided tape 64 since the conductive double-sided tape 52 etc. is not disposed under the metallic plate 62.
It is to be noted that the metallic plate 62 extends in a gap between the outer peripheral end surface 18b of the display 18 and the outer wall (vertical wall 32) along the outer peripheral end surface 18b in the right-and-left direction. Thus, the influence of erosion of the inner space of the first chassis 12A due to provision of the projecting part 62b is minimal, and the reduction in width of the bezel member 26 is not prevented.
As described above, the metallic sheet 66 may be stuck onto the front surface 38b of the projecting part 62b or may be stuck onto the back surface 38c. However, when the metallic sheet 66 is stuck onto the back surface 38c side, it is necessary to control so as not to influence the air-tightness by the double-sided tape 64. Since the metallic sheet 66 has an adhesive layer on its back surface 66a in the first place, it is more efficient to stick this directly onto the front surface 38b.
Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present invention. Accordingly, the scope of the invention should be limited only by the attached claims.
Number | Date | Country | Kind |
---|---|---|---|
2020-199385 | Dec 2020 | JP | national |