CN217035668U

CN217035668U - Piezoelectric actuator

Info

Publication number: CN217035668U
Application number: CN202123231939.3U
Authority: CN
Inventors: 不公告发明人
Original assignee: Suzhou Lingdong Jiaxin Technology Co ltd
Current assignee: Suzhou Lingdong Jiaxin Technology Co ltd
Priority date: 2021-12-21
Filing date: 2021-12-21
Publication date: 2022-07-22
Anticipated expiration: 2031-12-21

Abstract

The present invention discloses a piezoelectric actuator, including: a circuit board (1) provided with a first electrode (10); the piezoelectric driving piece (3) is arranged on the surface of the circuit board (1), and the piezoelectric driving piece (3) is provided with a second electrode (30) electrically connected with the first electrode (10); and the sealing element (2) is coated outside the piezoelectric driving element (3) and is connected with the circuit board (1), and a closed cavity for accommodating the piezoelectric driving element (3) is formed between the sealing element (2) and the circuit board (1). The piezoelectric driving piece is arranged in the closed cavity, is slightly influenced by external adverse factors such as humidity and the like, greatly reduces the unidirectional migration rate of metal electrode ions, and reduces the probability of short circuit.

Description

Piezoelectric actuator

Technical Field

The utility model relates to the technical field of piezoelectricity, in particular to a piezoelectric driver.

Background

The piezoelectric driver manufactured by the piezoelectric technology has the advantages of small thickness, low power consumption, high response speed, wide working frequency band and the like, is usually used for providing tactile feedback, and has great potential in the aspect of man-machine interaction application.

However, the conventional piezoelectric actuator still has certain defects, for example, the piezoelectric material is fragile and fragile, so that the piezoelectric actuator is easy to break and fail due to bending and the like during use. For another example, environmental factors such as environmental humidity have a great influence on the piezoelectric actuator, and metal electrode ions are likely to migrate unidirectionally to cause short circuit under long-term operation, which affects the service life and reliability. As another example, when manufacturing the piezoelectric actuator, it is necessary to weld the electrode leads, and the welding of the electrode leads is time-consuming.

Accordingly, there is a need for improvements in the art that overcome the deficiencies in the prior art.

SUMMERY OF THE UTILITY MODEL

It is an object of the present invention to provide a piezoelectric actuator that is less affected by the external environment.

To achieve the above object, the present invention provides a piezoelectric actuator, including:

a circuit board provided with a first electrode;

the piezoelectric driving piece is arranged on the surface of the circuit board and provided with a second electrode electrically connected with the first electrode; and the number of the first and second groups,

and the sealing element is coated outside the piezoelectric driving element and is connected with the circuit board, and a closed cavity for accommodating the piezoelectric driving element is formed between the sealing element and the circuit board.

Further, the sealing member including encircle in piezoelectricity driving piece periphery and with sealed pilot ring that the circuit board links to each other and cover in piezoelectricity driving piece deviates from on the surface of circuit board and with the sealing glue layer that sealing glue circle links to each other, sealing glue circle sealing glue layer with form between the circuit board and hold the closed chamber of piezoelectricity driving piece.

Further, the sealing rubber ring partially covers the surface of the piezoelectric driving piece, which faces away from the circuit board.

Furthermore, the circuit board is a PCB or a flexible circuit board, and the piezoelectric actuator further includes a reinforcing layer connected to a surface of the circuit board away from the piezoelectric actuator.

Furthermore, at least the outer edge of the piezoelectric driving piece is provided with the second electrode, at least part of the first electrode is positioned outside the piezoelectric driving piece, and the piezoelectric driver further comprises a conductive connecting piece connected between the second electrode and the first electrode and an adhesive layer connected between the piezoelectric driving piece and the circuit board.

Furthermore, at least the bottom surface of the piezoelectric driving part is provided with the second electrode, the first electrode and the second electrode are oppositely arranged, the piezoelectric driver further comprises a conductive connecting layer connected between the second electrode and the first electrode, and the piezoelectric driving part is connected with the circuit board through the conductive connecting layer.

Furthermore, at least the bottom surface of the piezoelectric driving part is provided with the second electrode, the first electrode and the second electrode are oppositely arranged, the piezoelectric driver further comprises a glue layer connected between the second electrode and the first electrode, and the second electrode is directly contacted and conducted with the first electrode.

Compared with the prior art, the utility model has the following beneficial effects:

1. through setting up the cladding in the outside sealing member that links to each other with the circuit board of piezoelectricity driving piece for the piezoelectricity driving piece is sealed in closed intracavity, and isolated with external, has eliminated the influence that adverse factors such as external humidity led to the fact the piezoelectricity driving piece, has reduced the one-way migration's of metal electrode ion speed by a wide margin, has reduced the probability that the short circuit takes place. Moreover, the sealing element can be matched with the circuit board to wrap the piezoelectric driving element in an all-around mode, a better protection effect can be achieved on the piezoelectric driving element, the piezoelectric driving element is connected with the circuit board more firmly, and the service life and the service reliability of the piezoelectric driver are better.

2. Through set up the strengthening layer on the circuit board, can effectual holistic rigidity of improvement piezoelectric actuator and intensity, can effectually prevent piezoelectric actuator because of buckling the cracked trouble that leads to.

3. Make first electrode and second electrode electricity connect through conducting resin, perhaps make first electrode and second electrode direct contact switch on through setting up the glue film and exerting the pressurize pressure, need not the welding electrode lead wire, can improve production efficiency effectively.

Drawings

Fig. 1 is a schematic sectional view of a piezoelectric actuator in embodiment 1 of the present invention.

Fig. 2 is a sectional view of the piezoelectric actuator shown in fig. 1 taken along a sectional direction indicated by a-a.

Fig. 3 is an enlarged view of a portion I in fig. 1.

Fig. 4 is a schematic sectional view of a piezoelectric actuator in embodiment 2 of the present invention.

Fig. 5 is an enlarged view of section II in fig. 4.

Fig. 6 is a schematic sectional view of the piezoelectric actuator in embodiment 3 of the present invention.

Fig. 7 is an enlarged view of the section III in fig. 6.

Figure 8 is a top view of a piezoelectric actuator in accordance with an embodiment of the present invention, the piezoelectric actuator having a circular shape.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying figures are described in detail below. It is to be understood that the specific embodiments described herein are merely illustrative of and not restrictive on the broad application. It should be further noted that, for the convenience of description, only some of the structures related to the present application are shown in the drawings, not all of the structures. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

The terms "comprising" and "having," as well as any variations thereof, in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein may be combined with other embodiments.

As shown in fig. 1 to 8, a piezoelectric actuator according to a preferred embodiment of the present invention includes a circuit board 1, a sealing member 2, and a piezoelectric actuator 3.

The piezoelectric driving member 3 is disposed on the surface of the circuit board 1, the circuit board 1 is provided with a first electrode 10 (usually, a copper-leaking surface of the circuit board 1), the piezoelectric driving member 3 is provided with a second electrode 30 disposed corresponding to the first electrode 10, and the second electrode 30 is electrically connected to the first electrode 10. The number of the second electrodes 30 may be multiple, and each second electrode 30 is correspondingly provided with at least one first electrode 10, and when connected, the two corresponding electrodes are electrically connected to enable a voltage to be applied to the piezoelectric driving member 3 to drive the piezoelectric driving member 3 to vibrate.

The piezoelectric driver 3 has a piezoelectric effect, which will produce vibration when a voltage is applied to it, thereby achieving vibration feedback. A circuit is provided in the circuit board 1, and it can be connected to a power supply module, a control module, and the like, to apply a voltage to the piezoelectric driving member 3, so that the piezoelectric driving member 3 vibrates. The piezoelectric driver 3 is made of a piezoelectric material, which may be, for example, lead zirconate titanate piezoelectric ceramic, piezoelectric single-crystal lithium niobate, or organic piezoelectric material PVDF.

The sealing element 2 is wrapped outside the piezoelectric driving element 3 and connected with the circuit board 1, and a closed cavity for accommodating the piezoelectric driving element 3 is formed between the sealing element and the circuit board 1. It can be understood that because piezoelectric driving piece 3 locates and seals the intracavity, consequently, can keep apart external environment and whole piezoelectric driving piece 3, eliminated adverse factor such as external humidity and to the influence that piezoelectric driving piece 3 caused, reduced the one-way migration's of metal electrode ion speed by a wide margin, reduced the probability that the short circuit takes place. Moreover, sealing member 2 can cooperate the omnidirectional cladding of omnidirectional with circuit board 1 and live piezoelectric drive piece 3, can play better protection effect to piezoelectric drive piece 3, makes piezoelectric drive piece 3 more firm with being connected of circuit board 1, and piezoelectric actuator's life and service reliability are better.

Further, referring to fig. 3, the piezoelectric actuator 3 includes a bottom surface 32 connected to the circuit board 1 and a front surface 31 facing away from the bottom surface 32. The sealing member 2 includes a sealing rubber ring 21 surrounding the periphery of the piezoelectric actuator 3 and connected to the circuit board 1, and a sealing rubber layer 22 sealing the top of the sealing member 2. The sealing rubber layer 22 covers the front surface 31 of the piezoelectric driving element 3 and is connected with the sealing rubber ring 21 surrounding the periphery, so that the sealing rubber ring 21, the sealing rubber layer 22 and the circuit board 1 form the closed cavity. Because sealing rubber ring 21 and sealing rubber layer 22 all link to each other with piezoelectric driving piece 3, consequently can effectual improvement piezoelectric driving piece 3 and the fastness of being connected between the circuit board 1, prevent that both separate because of the vibration.

The sealing rubber ring 21 preferably partially covers the surface of the piezoelectric actuator 3 facing away from the circuit board 1 (i.e. on the front surface 31), and referring to fig. 3, the sealing rubber ring 21 is generally thicker than the sealing rubber layer 22, so that the connection firmness and sealing reliability can be better improved.

The material of the sealing rubber ring 21 and the material of the sealing rubber layer 22 may be the same or different, preferably, the material of the sealing rubber ring 21 is UV glue, and the material of the sealing rubber layer 22 is waterproof ink.

The circuit board 1 may be a rigid PCB board or a flexible circuit board. In order to increase the rigidity of the circuit board 1, the piezoelectric actuator further comprises a reinforcing layer 7 disposed on the bottom surface of the circuit board 1, i.e. the surface of the circuit board 1 facing away from the piezoelectric actuator 3. The reinforcing layer 7 may be a metal reinforcing layer such as stainless steel or aluminum alloy, or an organic material reinforcing layer such as PI, PET, PC, or PEEK. Obviously, after setting up strengthening layer 7, the holistic intensity of piezoelectric actuator and rigidity are better, are difficult for buckling deformation to the inside fragile piezoelectric material of protection that can be better, the reliability of assurance performance.

It will be appreciated that the shape of the piezoelectric actuator is not limited, and may be, for example, rectangular as shown in fig. 2, or circular as shown in fig. 6.

The position of the second electrode 30 on the piezoelectric driver 3 is not limited, and it may be provided, for example, on one or more of the front face 31, the outer circumferential face 33 and the bottom face 32 of the piezoelectric driver 3. Referring to fig. 1 and 4, the piezoelectric driver 3 preferably has portions of the second electrode 30 on each of the front surface 31, the outer peripheral surface 33, and the bottom surface 32.

The connection between the piezoelectric actuator 3 and the circuit board 1 can be made in various ways, and three possible embodiments are described below.

Example 1

In the embodiment 1, the second electrode 30 is disposed at least on the periphery of the piezoelectric actuator 3, for example, the second electrode 30 may be disposed on the periphery of the front surface 31 of the piezoelectric actuator 3, or on the periphery 33 of the piezoelectric actuator 3, or may be connected to the periphery of the front surface 31 of the piezoelectric actuator 3 and the periphery 33 of the piezoelectric actuator 31, or of course, referring to fig. 1 to 3, the second electrode 30 may be disposed on the front surface 31, the periphery 33 and the bottom surface 32 of the piezoelectric actuator 3.

The piezoelectric driving element 3 is connected with the circuit board 1 through the adhesive layer 5, glue can be dispensed or coated on the bottom surface 32 of the piezoelectric driving element 3 or the surface of the circuit board 1, then the piezoelectric driving element 3 is attached to the circuit board 1, the adhesive layer 5 can be formed after the glue is cured, and the piezoelectric driving element 3 is adhered to the circuit board 1.

Preferably, the adhesive layer 5 is spread over the entire bottom surface 31 of the piezoelectric actuator 3 and is connected to the sealing rubber ring 21 at the periphery thereof, so as to further improve the sealing effect.

The position of the first electrode 10 on the circuit board 1 is adjacent to the position of the corresponding second electrode 30, and when the piezoelectric actuator 3 is mounted on the circuit board 1 in an aligned manner, at least a portion of the first electrode 10 is exposed from the piezoelectric actuator 31, so as to connect the second electrode 30 and the first electrode 10 via the conductive connection member 4.

The material of the conductive connecting member 4 is preferably a conductive adhesive, such as a conductive epoxy material, an ACF conductive adhesive, a conductive silver adhesive, etc., which can conveniently connect the second electrode 30 and the first electrode 10 and form the conductive connecting member 4 after curing.

In order to make the piezoelectric driver 3 perform better vibration transmission, the material of the adhesive layer 5 is preferably a material with strong adhesive force and Shore-D hardness (Shore D) greater than 50D after curing.

Example 2

In embodiment 2, at least the bottom surface 31 of the piezoelectric actuator 3 is provided with the second electrode 30, the first electrode 10 provided on the circuit board 1 is disposed opposite to the second electrode 30, and when the piezoelectric actuator 3 is aligned and bonded to the circuit board 1, the second electrode 30 and the first electrode 10 are bonded to each other. Referring to fig. 4 and 5, the second electrode 30 in embodiment 2 may also be located on the front face 31, the outer peripheral face 33 and the bottom face 32 of the piezoelectric driver 3 at the same time.

In the present embodiment, the second electrode 30 and the first electrode 10 are connected by the conductive connection layer 40, and similarly, the material of the conductive connection layer 40 is preferably a conductive adhesive, such as a conductive epoxy material, an ACF conductive adhesive, a conductive silver adhesive, or the like, which forms the conductive connection layer 40 after being cured. The conductive connecting layer 40 can not only connect the piezoelectric actuator 3 to the circuit board 1, but also realize the electrical connection between the second electrode 30 and the first electrode 10, so that the step of connecting the second electrode 30 and the first electrode 10 by using the conductive connecting member 4 after connecting the piezoelectric actuator 3 and the circuit board 1 can be omitted, and the preparation efficiency is higher.

Of course, in order to improve the connection firmness, the non-electrode area on the piezoelectric driving member 3 and the circuit board 1 may be glued and bonded by glue.

Example 3

Embodiment 3 is similar to embodiment 2, and referring to fig. 6 and 7, at least the bottom surface 31 of the piezoelectric actuator 3 is provided with a second electrode 30, the first electrode 10 on the circuit board 1 is arranged opposite to the second electrode 30, and when the piezoelectric actuator 3 is aligned and attached to the circuit board 1, the second electrode 30 and the first electrode 10 are attached.

Embodiment 3 differs from embodiment 2 in that the second electrode 30 and the first electrode 10 are connected by the adhesive layer 6. The second electrode 30 and the first electrode 10 are electrically conductive by direct contact, independent of the conductivity of the glue layer 6, i.e. the glue layer 6 may be made of a non-conductive material. Specifically, the glue that forms glue film 6 adopts the glue that mobility is less than 1500cps, and when forming glue film 6, is greater than 0.1Mpa to piezoelectric drive piece 3's pressurize pressure, through control pressure, can be so that glue film 6 thins, because the electrode surface is not completely level and smooth, its microcosmic surface is unevenness, consequently can make the bump on two electrode surfaces contact and switch on.

The utility model also provides a preparation method of the piezoelectric actuator, which is used for preparing the piezoelectric actuator and comprises the following steps:

s1, connecting a piezoelectric driving piece 3 with a circuit board 1;

s2, sealing glue is sealed at the edge of the piezoelectric driving piece 3 to form a sealing gasket 21 which is arranged on the periphery of the piezoelectric driving piece 3 in a surrounding mode and connected with the circuit board 1;

and S3, sealing glue on the exposed surface of the piezoelectric driving part 3 to form a sealing glue layer 22 which covers the surface of the piezoelectric driving part 3 and is connected with the sealing glue ring 21.

Through the above steps, the piezoelectric actuator 3 can be sealed in the closed cavity formed between the sealant ring 21, the sealant layer 22 and the circuit board 1.

In order to ensure better molding quality, step S20 is further included between step S2 and step S3, baking and curing are performed, and the sealing rubber ring 21 is rapidly cured and molded by heating and drying, so that the original sealing rubber ring 21 is not damaged when glue is subsequently applied to the exposed surface (i.e., the front surface 31) of the piezoelectric driving element 3. Likewise, step S30 may be further included after step S3. baking and curing are performed to rapidly cure and mold the sealant layer 22, so as to form the sealing member 2 together with the sealant ring 21.

In order to ensure the quality of the manufactured piezoelectric driver, a step S4 of detecting the package can be arranged after the step S3, the product prepared in the step S3 is detected in the aspects of electrical performance, appearance and the like, and the qualified product is packaged and put in storage.

The specific steps included in the above step S1 are different for different structures of piezoelectric drivers.

In molding the piezoelectric actuator of the structure described in embodiment 1, step S1 includes the steps of:

s10, arranging glue on the circuit board 1 and/or the piezoelectric driving piece 3;

s11, attaching the piezoelectric driving piece 3 to the circuit board 1, so that at least part of the first electrode 10 is exposed out of the piezoelectric driving piece 3;

s12, solidifying glue between the circuit board 1 and the piezoelectric driving piece 3 to form an adhesive layer 5;

s13, connecting the second electrode 30 and the first electrode 10 through a conductive adhesive;

s14, solidifying the conductive adhesive to form the conductive connecting piece 4.

In step S10, glue may be applied to the circuit board 1 and/or the piezoelectric driving element 3 by dispensing or gluing, so that the piezoelectric driving element 3 and the circuit board 1 can be adhered by the glue. In step S12, the glue can be cured quickly by baking and curing to form the adhesive layer 5, so that the piezoelectric actuator 3 and the circuit board 1 can be connected reliably.

Since the second electrode 30 is disposed on the outer edge of the piezoelectric actuator 3 and the first electrode 10 is partially exposed from the piezoelectric actuator 3 in embodiment 1, step S13 may coat a conductive adhesive such as a conductive silver adhesive between the second electrode 30 and the first electrode 10, and form the conductive connection element 4 after curing.

In molding the piezoelectric actuator of the structure described in embodiment 2, step S1 includes the steps of:

s10, arranging conductive adhesive on the second electrode 30 and/or the first electrode 10;

s11, attaching the piezoelectric driving piece 3 to the circuit board 1, and pressing the conductive adhesive between the second electrode 30 and the first electrode 10;

and S12, solidifying the conductive adhesive between the second electrode 30 and the first electrode 10 to form a conductive connecting layer 40.

In step S10, a conductive adhesive may be disposed on the second electrode 30 and/or the first electrode 10 by dispensing or gluing.

In step S12, the conductive adhesive can be cured into the conductive connection layer 40 by baking and curing, and since the conductive adhesive has a conductive property, the conductive connection layer 40 can perform both the connection function and the conductive function, and step S13 and step S14 can be omitted when the piezoelectric actuator having the structure described in embodiment 1 is formed.

In molding the piezoelectric actuator of the structure described in embodiment 3, step S1 includes the steps of:

s10, glue is arranged on the second electrode 30 and/or the first electrode 10;

s11, attaching the piezoelectric driving part 3 to the circuit board 1, and applying pressure maintaining pressure to the piezoelectric driving part 3 and the circuit board 1 to enable the first electrode 10 to be in contact with the second electrode 30;

and S12, curing the glue connected between the second electrode 30 and the first electrode 10 to form a glue layer 6.

In step S10, glue may be applied to the second electrode 30 and/or the first electrode 10 by dispensing or gluing.

In step S11, since the fluidity of the glue is less than 1500cps, the glue can be thinned by applying the holding pressure to the piezoelectric driver 3, so that the second electrode 30 and the first electrode 10 are in contact conduction. In order to facilitate the contact between the first electrode 10 and the second electrode 30, it is preferable that the fluidity of the glue is less than 1500cps and the applied holding pressure is more than 0.1 Mpa.

In step S12, the glue may be rapidly cured by baking and curing to form the glue layer 6.

The utility model has the following advantages:

1. through setting up the cladding in the outside sealing member that links to each other with the circuit board of piezoelectricity driving piece for the piezoelectricity driving piece is sealed in closed intracavity, and isolated with external, has eliminated the influence that adverse factors such as external humidity led to the fact the piezoelectricity driving piece, has reduced the one-way migration's of metal electrode ion speed by a wide margin, has reduced the probability that the short circuit takes place. Moreover, the sealing element can be matched with the circuit board to wrap the piezoelectric driving element in an all-dimensional manner, so that a better protection effect can be achieved on the piezoelectric driving element, the piezoelectric driving element is more firmly connected with the circuit board, and the service life and the service reliability of the piezoelectric driver are better.

2. Through set up the strengthening layer on the circuit board, can effectual improvement piezoelectric actuator holistic rigidity and intensity, can effectually prevent piezoelectric actuator because of the cracked trouble that buckles and lead to.

The above is only one embodiment of the present invention, and any other modifications based on the concept of the present invention are considered to be within the scope of the present invention.

Claims

1. A piezoelectric driver, comprising:

a circuit board (1) provided with a first electrode (10);

the piezoelectric driving piece (3) is arranged on the surface of the circuit board (1), and the piezoelectric driving piece (3) is provided with a second electrode (30) electrically connected with the first electrode (10); and the number of the first and second groups,

and the sealing element (2) is coated outside the piezoelectric driving element (3) and is connected with the circuit board (1), and a closed cavity for accommodating the piezoelectric driving element (3) is formed between the sealing element (2) and the circuit board (1).

2. The piezoelectric actuator according to claim 1, wherein the sealing member (2) includes a sealing rubber ring (21) surrounding the periphery of the piezoelectric actuator (3) and connected to the circuit board (1), and a sealing adhesive layer (22) covering the surface of the piezoelectric actuator (3) facing away from the circuit board (1) and connected to the sealing rubber ring (21), and a closed cavity accommodating the piezoelectric actuator (3) is formed among the sealing rubber ring (21), the sealing adhesive layer (22) and the circuit board (1).

3. A piezo actuator according to claim 2, wherein the sealing rubber ring (21) partially covers the surface of the piezo actuator (3) facing away from the circuit board (1).

4. A piezo actuator according to claim 1, wherein the circuit board (1) is a PCB board or a flex-circuit board, the piezo actuator further comprising a stiffening layer (7) attached to a surface of the circuit board (1) facing away from the piezo actuator (3).

5. A piezo-electric actuator as claimed in any one of claims 1 to 4, characterized in that at least the outer edge of the piezo-electric actuator (3) is provided with the second electrode (30), the first electrode (10) being located at least partially outside the piezo-electric actuator (3), the piezo-electric actuator further comprising an electrically conductive connection (4) connected between the second electrode (30) and the first electrode (10) and an adhesive layer (5) connected between the piezo-electric actuator (3) and the circuit board (1).

6. A piezo-electric actuator as claimed in any one of claims 1 to 4, characterized in that at least the bottom surface of the piezo-electric actuator (3) is provided with the second electrode (30), the first electrode (10) is arranged opposite to the second electrode (30), the piezo-electric actuator further comprises an electrically conductive connection layer (40) connected between the second electrode (30) and the first electrode (10), the piezo-electric actuator (3) and the circuit board (1) being connected by means of the electrically conductive connection layer (40).

7. A piezo-electric actuator as claimed in any one of claims 1 to 4, characterized in that at least the bottom side of the piezo-electric actuator (3) is provided with the second electrode (30), the first electrode (10) is arranged opposite to the second electrode (30), the piezo-electric actuator further comprises a glue layer (6) connected between the second electrode (30) and the first electrode (10), and the second electrode (30) and the first electrode (10) are in direct contact.