VIBRATION DEVICE, VIBRATION APPARATUS, AND MANUFACTURING METHOD OF VIBRATION DEVICE

Provided are a vibration device, a vibration apparatus, and a method for manufacturing a vibration device. The vibration device includes a vibration element; a substrate having a placement surface on which the vibration element is placed; a wall portion formed around the placement surface; and a potting layer for sealing the vibration element placed on the placement surface of the substrate inside the wall portion. The vibration device is manufactured by forming the substrate by laminating a protective film having an opening on a base film; placing the vibration element in the opening of the protective film on the substrate; and sealing the vibration element placed in the opening of the protective film on the substrate by potting.

RELATED APPLICATION CROSS-REFERENCE

This application claims the priority benefits of Japanese application no. 2022-123740, filed on Aug. 3, 2022. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

BACKGROUND

Technical Field

The disclosure relates to a vibration device including a vibration element, a vibration apparatus including such a vibration device, and a manufacturing method of a vibration device for manufacturing such a vibration device.

Related Art

Vibration elements that generate vibrations are used in various electronic devices, such as operation devices like mice, keyboards, and game controllers, and communication devices like smartphones and tablet computers, and the like. For example, Patent Literature 1 discloses a vibration device using a piezoelectric element as a vibration element. In the vibration device using a piezoelectric element, it is easy for the piezoelectric element to fail due to vibrations, so lamination processing with PET (Polyethylene Terephthalate) film is required.

CITATION LIST

Patent Literature

SUMMARY

Technical Problem

However, the lamination processing using PET has a problem that the vibration caused by the vibration element is easily attenuated.

The disclosure provides a vibration device capable of suppressing attenuation of vibrations.

The disclosure provides a vibration apparatus including a vibration device according to the disclosure.

Furthermore, the disclosure provides a manufacturing method of the vibration device.

Solution to Problem

A vibration device disclosed in this application includes a vibration element; a substrate having a placement surface on which the vibration element is placed; a wall portion formed around the placement surface; and a potting layer for sealing the vibration element placed on the placement surface of the substrate inside the wall portion surround by the wall portion.

Furthermore, a vibration apparatus disclosed in this application includes the vibration device.

Furthermore, a manufacturing method of the vibration device disclosed in this application includes forming a substrate by laminating a protective film having an opening on a base film; placing the vibration element in the opening of the protective film on the substrate; and sealing the vibration element placed in the opening of the protective film on the substrate by potting.

Effects

The vibration device and the like disclosed in this application have excellent effects, such as the ability to suppress the attenuation of vibrations.

DESCRIPTION OF THE EMBODIMENTS

In the vibration device, the substrate includes a base film on which the placement surface is formed; and a protective film laminated on the base film and having an opening corresponding to the placement surface. The wall portion is formed by a step between the placement surface of the base film and the protective film.

In the vibration device, the potting layer is formed so as not to protrude from the inside of the wall portion.

In the vibration device, the potting layer has a height from the placement surface equal to or less than the wall portion.

In the vibration device, the vibration element is a thin-film piezoelectric element that vibrates when energized, and the substrate is a thin-film flexible printed circuit board.

Application Example

Hereinafter, embodiments will be described with reference to the drawings. The vibration apparatus disclosed in this application is applicable to devices that convey situations or information to users through vibrations, such as devices with integrated operation parts and display parts like game devices and game device controllers. Hereinafter, a vibration apparatus VA applied to a game device will be described as an example with reference to the drawings.

<Appearance of Vibration Apparatus VA>

FIGS.1and2are schematic appearance diagrams showing an example of the appearance of the vibration apparatus VA disclosed in this application.FIG.1is a schematic perspective view showing the front side of the vibration apparatus VA, andFIG.2is a schematic perspective view showing the back side of the vibration apparatus VA. The vibration apparatus VA includes a housing1having a substantially rectangular plate shape, and a display unit10such as a rectangular liquid crystal panel is arranged at the center of the front surface of the housing1, with holding portions11for users to grip arranged on both sides of the display unit10. Operation units12, such as operation buttons for users to operate with their thumbs, are arranged on the holding portions11. On the back surface of the housing1, vibration units13that generate vibrations are arranged at four positions where fingers other than the user's thumb may touch.

<Internal Structure of Vibration Apparatus VA>

FIG.3is a schematic perspective view showing an example of the inside of the vibration apparatus VA disclosed in this application. InFIG.3, the display unit10arranged on the front surface of the housing1of the vibration apparatus VA is removed such that the internal structure is visible. To make it easier to see the inside of the vibration apparatus VA,FIG.3shows only the housing1and vibration devices2arranged inside the housing1. As illustrated inFIG.3, four vibration devices2are arranged inside the housing1, and the arrangement positions of each vibration device2correspond to the positions of the vibration units13on the back surface of the housing1. With such an arrangement, vibrations from the vibration devices2are transmitted to the user's fingertips through the vibration units13of the housing1.

FIG.4is a schematic perspective view showing an example of the vibration device2disclosed in this application. The vibration device2includes a vibration element21, a substrate having a substantially rectangular thin film shape, and a terminal portion202bconnected to a control unit (not shown) for controlling the vibration element21. The vibration element21is placed on a placement surface20aof the substrate20. The substrate20is a flexible printed circuit board (FPC board) having flexibility.

FIG.5is a schematic perspective view showing an example of the substrate20provided in the vibration device2disclosed in this application.FIG.6is a schematic exploded perspective view showing an example of the substrate20provided in the vibration device2disclosed in this application. The substrate20provided in the vibration device2is formed by laminating a thin film-shaped protective film201on a thin film-shaped base film200. The thickness of the base film200is about 50 μm. A part of the surface of the base film200forms the substantially square placement surface20a. A pair of printed wirings202are formed on the base film200. One end of the printed wirings202serves as an electrode portion202aconnected to the vibration element21, and the other end serves as the terminal portion202b. The protective film201is a thin film with a thickness of about 50 μm made of resin such as PET (Polyethylene Terephthalate), and it covers the surface of the base film200. The protective film201has openings corresponding to the placement surface20aand the terminal portion202bof the printed wirings202. The opening corresponding to the placement surface20aforms a step of 50 μm between the upper surface of the base film200and the upper surface of the protective film201, and due to this step, the opening edge of the protective film201becomes a wall portion20b.

FIG.7is a schematic exploded perspective view showing an example of the vibration device2disclosed in this application.FIG.7shows various members stacked on the placement surface20aof the substrate20provided in the vibration device2in a disassembled manner. The placement surface20ain the base film200of the substrate20is a substantially square-shaped area within the opening of the stacked protective film201. The placement surface20ahas an adhesive layer22, the vibration element21, a conductive paste23, and a potting layer24stacked thereon. The adhesive layer22is a layer that adheres the vibration element21to the base film200and is formed by an adhesive. The vibration element21is formed using, for example, a piezoelectric element having piezoelectricity such as PZT (lead zirconate titanate), and vibrates when energized. The conductive paste23is formed by a conductive adhesive such as silver paste, which electrically connects the vibration element21and the electrode portion202aof the printed wirings202. The potting layer24is formed by a sealing agent made of cured resin.

FIG.8is a schematic cross-sectional view showing an example of the vibration device2disclosed in this application.FIG.8schematically shows a cross-section of the vibration device2cut along line A-B inFIG.4and passing through the placement surface20a. The substrate20has the placement surface20aand the wall portion20bformed by laminating the protective film201having openings on the base film200. The film thicknesses of the base film200and the protective film201are both 50 μm. Thus, the area surrounded by the wall portion20bon the placement surface20aforms a recess having a height of 50 μm, which serves as a dam to prevent the outflow of potting resin. The adhesive layer22, the vibration element21, and the potting layer24are laminated on the placement surface20a. The potting layer24for sealing members such as the vibration element21is filled such that its height from the placement surface is equal to or less than 50 μm. That is, the potting layer24is formed such that its height from the placement surface20ais equal to or less than the height of the wall portion20band does not protrude from inside the wall portion20b. It should be noted that the height of the potting layer24may be filled to slightly exceed the height of the wall portion20bif it is within a range that allows attenuation of vibrations; however, it is preferable to ensure that it does not protrude out from inside the wall portion20b.

<Manufacturing Method of Vibration Device2>

Next, the manufacturing method of the vibration device2according to this disclosure will be described.FIGS.9to13are explanatory diagrams showing an example of the manufacturing method of the vibration device2according to this disclosure.FIG.9shows a process of forming the substrate20by attaching the printed wirings202to the base film200and laminating the protective film201thereon. By adhering the protective film201having openings formed to the base film200, the placement surface20aand the wall portion20bare formed. Moreover, by adhering the protective film201to the base film200, most of the printed wirings202is covered, and the electrode portion202aand the terminal portion202bare exposed from the openings of the protective film201.

FIG.10shows a process of forming the adhesive layer22on the placement surface surrounded by the wall portion20bfrom the state shown inFIG.9. The adhesive layer22is formed as a layer with a thickness of 10 to 30 μm by applying a liquid adhesive or laying a sheet-like adhesive on the placement surface20a. By using a liquid adhesive or a thin-film adhesive sheet, it is possible to form the adhesive layer22with a substantially uniform film thickness. Since the adhesive layer22is a layer for adhering the vibration element21to the base film200, it is preferable that the application range is equivalent to the surface on the adhesive side of the vibration element21.

FIG.11shows a process of placing the vibration element21on the adhesive layer22formed on the placement surface20awithin the opening of the protective film201from the state shown inFIG.10. By placing the vibration element21on the adhesive layer22formed on the placement surface20aof the base film200of the substrate20and making it adhere, the vibration element21is temporarily adhered. The substrate20with the temporarily adhered vibration element21is heated in a heat-curing furnace, causing the adhesive layer22to cure and adhere the vibration element21to the substrate20.

FIG.12shows a process of forming the conductive paste23from the state shown inFIG.11.FIG.12shows an enlarged view of the area around the conductive paste23. The layer of the conductive paste23is formed by applying silver paste to connect the electrode portion202aof the printed wirings202formed on the substrate20and the electrode of the vibration element21(not shown), and then curing it using a curing method such as heat curing or UV curing.

FIG.13shows a process of sealing the vibration element21placed within the opening on the substrate20with a potting agent from the state shown inFIG.12. The potting agent is poured into the opening on the substrate20where members such as the vibration element21are placed, that is, into the recess surrounded by the wall portion20b, and cured using a curing method such as heat curing or UV curing. In this way, the potting layer24is formed. The amount of potting agent poured is adjusted so as not to exceed the height of the wall portion20b. In this manner, the vibration device2is manufactured.

<Vibration Characteristics of Vibration Device2>

FIG.14is a graph showing an example of the vibration characteristics of the vibration device2disclosed in this application.FIG.14is a graph showing the relationship between time on the horizontal axis and vibration on the vertical axis. The solid line represents the vibration device2disclosed in this application, and the dashed line represents a conventional vibration device in which the vibration element is sealed with a PET laminate for comparison. The substrate and vibration element are under the same conditions. The conventional PET laminate-based vibration device is manufactured using a general manufacturing method, in which a PET laminate layer is formed on a 50 μm substrate and has a total film thickness of 120 μm. In the potting-based vibration device2disclosed in this application, since the potting agent is poured into the recess, it is possible to make the potting layer24thinner, and the 50 μm potting layer24is formed on the substrate20, resulting in a total film thickness of 100 μm. The driving conditions for both are set to a sinusoidal waveform with a voltage of 30V and a frequency of 200 Hz. Vibration is detected by irradiating laser light from a laser Doppler vibrometer onto the surface of the vibration element. The vibration device2disclosed in this application, which seals the vibration element21with the thin potting layer24, exhibits less attenuation of vibration and larger observed vibrations compared to conventional devices.

As described above, in the vibration element21disclosed in this application, a potting agent is poured into the recess formed by the wall portion20bto form the potting layer24having a height equal to or less than the wall portion20b. As a result, by protecting the vibration element21with the potting layer24, the vibration element21disclosed in this application can be improved in durability, and can suppress attenuation of vibration, among other excellent effects, to enhance high vibration performance.

Furthermore, since the vibration element21disclosed in this application forms the wall portion20bat a step formed by laminating the protective film201having openings on the base film200, it exhibit excellent effects such as being manufactured without complicating the process.

The disclosure is not limited to the embodiments described above and may be implemented in various other forms. Thus, the described embodiments are merely illustrative in all respects and should not be construed as limiting. The technical scope of the disclosure is defined by the claims and is not bound by the text of the specification. Furthermore, modifications and changes that belong to the equivalent scope of the claims are all within the scope of the disclosure.

For example, in the aforementioned embodiment, the wall portion20bis formed by laminating the protective film201having openings on the base film200has been shown, but the vibration device2disclosed in this application is not limited thereto and may be implemented in various forms. For instance, the vibration device2disclosed in this application may be implemented in various forms, such as forming the wall portion20bby providing a protrusion on the substrate20, as long as it is possible to pour the potting agent.

Moreover, for example, in the aforementioned embodiment, the application of the vibration apparatus VA disclosed in this application to a game device controller has been described, but the vibration apparatus VA disclosed in this application is not limited thereto and may be applied to various devices that convey situations or information to users through vibrations.