WO2022121773A1

WO2022121773A1 - Piezoelectric ceramic waterproof structure, piezoelectric ceramic apparatus and electronic device

Info

Publication number: WO2022121773A1
Application number: PCT/CN2021/135102
Authority: WO
Inventors: 曹伯承; 张小伟; 刘海永
Original assignee: 华为技术有限公司
Priority date: 2020-12-09
Filing date: 2021-12-02
Publication date: 2022-06-16
Also published as: CN214256810U

Abstract

Provided in the present application are a piezoelectric ceramic waterproof structure, a piezoelectric ceramic apparatus and an electronic device. The piezoelectric ceramic waterproof structure comprises: a conductive substrate; a piezoelectric ceramic sheet, which comprises a first connecting surface and a second connecting surface arranged opposite to each other, the first connecting surface being fixedly attached to the conductive substrate; an insulating waterproof seal member that has an annular structure and is sleeved on the outer periphery of the piezoelectric ceramic sheet, one end of the insulating waterproof seal member being in sealed connection to the conductive substrate; and a conductive waterproof seal member, which is in sealed connection to the other end of the insulating waterproof seal member, so as to seal the piezoelectric ceramic sheet in a sealing cavity enclosed by the conductive substrate, the insulating waterproof seal member and the conductive waterproof seal member; and the conductive waterproof seal member is electrically connected to the second connecting surface. The piezoelectric ceramic waterproof structure provided by the present application may enhance the waterproof performance of piezoelectric ceramic, and has good use reliability.

Description

A piezoelectric ceramic waterproof structure, piezoelectric ceramic device and electronic equipment

This application claims the priority of the Chinese patent application submitted to the State Intellectual Property Office on December 09, 2020, the application number is 202022986270.8, and the application name is "a piezoelectric ceramic waterproof structure, piezoelectric ceramic device and electronic equipment", which The entire contents of this application are incorporated by reference.

technical field

The present application relates to the field of terminal technology, and in particular, to a piezoelectric ceramic waterproof structure, a piezoelectric ceramic device and electronic equipment.

Background technique

Piezoelectric ceramics is an information functional material that converts mechanical energy and electrical energy into each other. Currently, it is widely used in buzzers, filters, transducers, transformers, igniters, piezoelectric sensors and other products. When charged, piezoelectric ceramics have natural properties that are sensitive to damp-heat conditions, and are prone to damp-heat stress defects under high temperature and high humidity conditions. The existing piezoelectric ceramic products have insufficient waterproof performance, and the piezoelectric ceramic sheets are easily attacked by water vapor and cause self-breakdown failure, thereby reducing the reliability of the products and shortening the service life of the products.

SUMMARY OF THE INVENTION

The present application provides a piezoelectric ceramic waterproof structure, a piezoelectric ceramic device and an electronic device, which can enhance the waterproof performance of the piezoelectric ceramic, so that the piezoelectric ceramic product has good reliability in use under humid heat conditions.

In a first aspect, a piezoelectric ceramic waterproof structure is provided, comprising: a conductive substrate; a piezoelectric ceramic sheet, including a first connection surface and a second connection surface arranged oppositely, the first connection surface being fixedly attached to the on the conductive substrate; an insulating and waterproof sealing member, in the form of a ring structure, is sleeved on the outer periphery of the piezoelectric ceramic sheet, and one end of the insulating waterproof sealing member is sealed with the conductive substrate; the conductive waterproof sealing member is connected with the The other end of the insulating waterproof seal is sealed and connected to seal the piezoelectric ceramic sheet in the sealed cavity enclosed by the conductive substrate, the insulating waterproof seal and the conductive waterproof seal; the conductive waterproof seal The component is electrically connected to the second connection surface.

According to the piezoelectric ceramic waterproof structure provided in the present application, the piezoelectric ceramic sheet is sealed in the sealing cavity surrounded by the conductive substrate, the insulating waterproof sealing member and the conductive waterproof sealing member, which can effectively isolate the water vapor, so that the piezoelectric ceramic sheet can effectively isolate the water vapor. The resistance to water vapor is significantly improved. On the one hand, the market failure rate of the piezoelectric ceramic waterproof structure in normal use can be reduced, the stability of the product can be effectively improved, and the user experience can be improved. On the other hand, due to the improved reliability of the piezoelectric ceramic waterproof structure, the product can work under a higher field strength, so that better performance, such as amplitude, can be obtained. It has been verified by experiments that the piezoelectric ceramic waterproof structure provided by the embodiments of the present application can achieve good reliability results under high temperature and high humidity conditions, ensuring that the product can work reliably under severe conditions of high temperature and high humidity, and has a low failure rate.

Optionally, the material of the conductive substrate includes, but is not limited to, conductive metal, conductive ceramic, conductive resin, conductive graphite, and the like.

For example, the material may be copper, stainless steel, aluminum, or nickel, or the like. At this time, the conductive substrate may be a copper substrate, a stainless steel substrate, an aluminum substrate, or a nickel substrate or the like.

Optionally, the piezoelectric ceramic sheet can be fixedly adhered to the conductive substrate through conductive glue.

In a possible design, the insulating waterproof sealing member includes a sealing ring and a sealing eaves connected to each other; the sealing ring is sleeved on the outer periphery of the piezoelectric ceramic sheet, one end is sealedly connected to the conductive substrate, and the other end is sealed. The sealing eave is connected; the sealing eave extends inward from the edge of the second connecting surface, and the front end is sealedly connected with the conductive waterproof seal.

In the present application, the sealing eaves are provided, so that the connection between the insulating waterproof sealing member and the conductive waterproof sealing member is located inside the projection of the piezoelectric ceramic sheet, rather than at the edge, so that the reliability of the sealing connection can be improved.

In a possible design, the sealing eave is in an annular structure, and a through hole is formed inside, the conductive waterproof seal is attached to the sealing eave, and the middle part of the conductive waterproof seal protrudes out of the inside the through hole and electrically connected to the second connection surface. Through the above arrangement, the conductive waterproof seal can be reliably pressed on the sealing eaves, so as to realize the reliability of the sealed connection between the two.

In a possible design, the piezoelectric ceramic waterproof structure further includes a circuit board and a first conductive foam structure, and the conductive waterproof seal is electrically connected to the circuit board through the first conductive foam structure.

Specifically, a first conductive foam structure can be arranged between the circuit board and the conductive waterproof seal, and two sides of the first conductive foam structure are respectively crimped on the circuit board and the conductive waterproof seal to achieve reliable electrical connection, so as to realize the electrical extraction of the piezoelectric ceramic waterproof structure.

In the present application, by setting the first conductive foam structure and the method of crimping the conductive waterproof seal, the welding stress introduced by the traditional welding method is avoided, and the crack of the piezoelectric ceramic caused by the welding stress is eliminated, thereby improving the reliability of the product and the Production consistency. In addition, the conductive foam has a certain flexibility, and the configuration of the conductive foam will not hinder the deformation of the piezoelectric ceramic sheet, thereby ensuring that the piezoelectric ceramic waterproof structure has reliable working performance.

Alternatively, the circuit board may be a printed circuit board.

Optionally, the circuit board may be a flexible board, a rigid board or a flexible-rigid combination board.

For example, the circuit board may be a flexible circuit board. The flexible circuit board is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film. It has the characteristics of high wiring density, light weight, thin thickness and good bendability.

In a possible design, the piezoelectric ceramic waterproof structure further includes a second conductive foam structure, and the conductive substrate is electrically connected to the circuit board through the second conductive foam structure.

In a possible design, the second conductive foam structure is an annular structure, sleeved on the outer periphery of the insulating waterproof seal, and one end of the second conductive foam structure is electrically connected to the conductive substrate , and the other end is electrically connected to the circuit board.

In a possible design, the piezoelectric ceramic waterproof structure further includes a first conductive connection layer, and the first connection surface is electrically connected to the conductive substrate through the first conductive connection layer.

In a possible design, the piezoelectric ceramic waterproof structure further includes a second conductive connection layer, and the conductive waterproof seal is electrically connected to the second connection surface through the second conductive connection layer.

Optionally, the first conductive connection layer and the second conductive connection layer may be metal thin films, and the metal may be silver, copper, gold, nickel, palladium, platinum, or the like.

For example, the first conductive connection layer and the second conductive connection layer may be silver paste layers. The thickness of the silver paste layer may be 20-50 microns. If the thickness of the silver paste layer is too thin, the piezoelectric ceramic sheet will not be fully covered with silver, and the reliability cannot be guaranteed; if the thickness of the silver paste layer is too thick, the cost will be greatly increased. In the embodiment of the present application, the thickness of the silver paste layer is selected. 20-50 microns (eg 25, 30, 35, 40 or 45 microns) can not only ensure the reliability of piezoelectric ceramics, but also take into account the cost requirements.

Optionally, the first conductive connection layer and the second conductive connection layer may be disposed on the piezoelectric ceramic sheet through processes such as sintering, vacuum evaporation, chemical deposition, and the like.

In a possible design, the insulating waterproof seal is composed of insulating waterproof glue or insulating film.

The insulating waterproof seal is composed of a material with insulating and waterproof properties, which is not limited in this application. For example, the material may be rubber, plastic, or resin.

Optionally, the insulating waterproof seal may be composed of insulating waterproof glue.

For example, the insulating waterproof glue may include one or more of epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane, acrylic resin, and the like.

Alternatively, the insulating waterproof seal can also be composed of an insulating film.

For example, the insulating film may be an inorganic insulating film, for example, may include insulating film materials such as silicon dioxide, silicon nitride, aluminum oxide, and aluminum nitride.

For another example, the insulating film may also be an organic insulating film. For example, insulating film materials such as polyimide, polyethylene, polyvinylidene fluoride, and polytetrafluoroethylene can be included.

Alternatively, the insulating film may be formed on the peripheral side and the upper side of the piezoelectric ceramic sheet by an evaporation process. At this time, the insulating film may also be referred to as evaporation coating or vacuum coating.

In a possible design, the conductive waterproof seal is composed of conductive waterproof glue or conductive metal.

Optionally, the conductive waterproof seal may be composed of conductive waterproof glue. The conductive waterproof glue can be formed by filling a certain concentration of conductive particles into the adhesive.

For example, the binder may be one or more of epoxy resin, silicone resin, polyimide resin, phenolic resin, polyurethane, acrylic resin, and the like.

For another example, the conductive particles may be powders of gold, silver, copper, aluminum, zinc, iron, nickel, graphite, and the like.

Alternatively, the conductive waterproof seal may be constructed of conductive metal.

For example, the conductive waterproof seal may be formed from evaporated or sputtered dense conductive metal. The conductive metal may be copper, aluminum, silver, or the like.

In a second aspect, a piezoelectric ceramic device is provided, comprising a processor and the piezoelectric ceramic waterproof structure provided in any possible design of the first aspect, the processor and the piezoelectric ceramic waterproof structure are electrically connected to each other. connect.

Optionally, the piezoelectric ceramic device can work by utilizing the positive piezoelectric effect of the piezoelectric ceramic, and at this time, the processor can receive and process the electrical signal generated by the piezoelectric ceramic waterproof structure. For example, the piezoelectric ceramic device may be a piezoelectric sensor (touch sensor), a pressure sensor, an acceleration sensor, a gyroscope, or the like.

Optionally, the piezoelectric ceramic device can also work by utilizing the inverse piezoelectric effect of the piezoelectric ceramic, and at this time, the processor can input a driving current (such as high-frequency alternating current) to the piezoelectric ceramic waterproof structure. For example, the piezoelectric ceramic device may be a buzzer, an ultrasonic transducer, an underwater acoustic transducer, a filter, a resonator, or the like.

In a third aspect, an electronic device is provided, including the piezoelectric ceramic device provided in the second aspect.

Optionally, the electronic device is a notebook computer, including a touchpad. The piezoelectric ceramic device is a piezoelectric sensor, and includes a plurality of piezoelectric ceramic waterproof structures, and the plurality of piezoelectric ceramic waterproof structures are arrayed inside the touch panel.

Description of drawings

FIG. 1 is a schematic structural diagram of a piezoelectric ceramic product in the prior art.

FIG. 2 is a schematic structural diagram of a piezoelectric ceramic waterproof structure provided in an embodiment of the present application.

FIG. 3 is a cross-sectional view of the piezoelectric ceramic waterproof structure 10 shown in FIG. 2 taken along the line A-A.

FIG. 4 is a cross-sectional view of the B-B section of the piezoelectric ceramic waterproof structure 10 shown in FIG. 2 .

FIG. 5 is a schematic structural diagram of another example of the piezoelectric ceramic waterproof structure provided by the embodiment of the present application.

FIG. 6 is a schematic structural diagram of a piezoelectric ceramic device provided by an embodiment of the present application.

FIG. 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

Reference numerals: 1. Piezoelectric ceramic sheet; 2. Metal substrate; 3. First silver paste layer; 4. Second silver paste layer; 5. First lead; 6. Second lead; 10. Piezoelectric ceramic waterproof Structure; 11, conductive substrate; 12, piezoelectric ceramic sheet; 13, insulating waterproof seal; 13a, sealing ring; 13b, sealing eaves; 14, conductive waterproof seal; 14a, main body; 14b, protrusion; 15, circuit board; 16, first conductive foam structure; 17, second conductive foam structure; 18, first conductive connection layer; 19, second conductive connection layer; 20, processor; 200, touch panel; 1000, electronic equipment.

Detailed ways

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present application, and should not be construed as a limitation on the present application.

In the description of the present application, it should be understood that the terms "first" and "second" are only used for description purposes, and cannot be interpreted as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, features defined as "first", "second" may expressly or implicitly include one or more of said features. In the description of the present application, "plurality" means two or more, unless otherwise expressly and specifically defined.

In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection, an electrical connection or can communicate with each other; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication between the two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In the description of this application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "side", "front", "rear", etc. is based on the orientation or positional relationship of installation, only For the convenience of describing the present application and simplifying the description, it is not indicated or implied that the referred device or element must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as a limitation of the present application.

In the description of this application, it should be noted that the term "and/or" is only an association relationship for describing associated objects, indicating that there can be three kinds of relationships, for example, A and/or B, which can mean that: exist independently A, there are both A and B, and there are three cases of B alone.

It should also be noted that, in the embodiments of the present application, the same reference numerals are used to represent the same component or the same component, and for the same components in the embodiments of the present application, only one of the parts or components may be marked as an example in the drawings. Where reference numerals are used, it should be understood that the same reference numerals apply to other identical parts or components.

Piezoelectric ceramics is a polycrystal with piezoelectric effect. It is named because the production process is similar to the production process of ceramics (raw material crushing, molding, high temperature sintering). Common piezoelectric ceramic materials are barium titanate. , lead titanate, lead zirconate titanate, titanium magnesium niobate, potassium sodium niobate, etc.

Piezoelectric ceramic material can produce piezoelectric effect after being polarized. When piezoelectric ceramic is deformed by external force in a certain direction, polarization phenomenon will be generated inside it, and it will appear on its two opposite surfaces at the same time. Positive and negative charges. When the external force is removed, it will return to an uncharged state, a phenomenon called the positive piezoelectric effect. When the direction of the force changes, so does the polarity of the charge. In short, piezoelectric ceramics produce an electrical effect due to force and deformation, which is called the positive piezoelectric effect.

On the contrary, when an electric field is applied to the polarization direction of piezoelectric ceramics, these piezoelectric ceramics will also deform. After the electric field is removed, the deformation of piezoelectric ceramics disappears. This phenomenon is called the inverse piezoelectric effect. In short, the effect of piezoelectric ceramic deformation due to applied voltage is called the inverse piezoelectric effect.

Because piezoelectric ceramics have the above-mentioned positive piezoelectric effect and inverse piezoelectric effect, piezoelectric ceramics become an information functional material that can convert mechanical energy and electrical energy into each other. The application range of piezoelectric ceramics is very wide, ranging from the development of the universe to the family life, and various functional products have been produced. Among them, the products that utilize the positive piezoelectric effect include pickups, igniters, piezoelectric sensors (touch sensors), pressure sensors, and gyroscopes. Products that utilize the negative piezoelectric effect include buzzers, ultrasonic transducers, underwater acoustic transducers, filters, and resonators.

FIG. 1 is a schematic structural diagram of a piezoelectric ceramic product in the prior art. The above-mentioned positive piezoelectric effect and inverse piezoelectric effect will be further introduced below with reference to FIG. 1 .

As shown in FIG. 1 , the upper and lower surfaces of the piezoelectric ceramic sheet 1 are respectively provided with a first silver paste layer 3 and a second silver paste layer 4 , and the piezoelectric ceramic sheet 1 is fixedly arranged on the second silver paste layer 4 . on the metal substrate 2. The metal substrate 2 and the first silver paste layer 3 are respectively welded with a first lead 5 and a second lead 6, through which the electrical connection with an external device (such as a processor or a power supply, etc.) is realized .

The piezoelectric ceramic product can use the positive piezoelectric effect to work. For example, the piezoelectric ceramic product can be a piezoelectric sensor. At this time, the user can deform the piezoelectric ceramic sheet 1 by pressing the metal substrate 2, thereby making the piezoelectric ceramic An electrical signal (induction signal) is generated inside the chip 1, and the electrical signal can be transmitted to an external processor through the first lead 5 and the second lead 6, and the processor determines the control command input by the user according to the electrical signal.

Alternatively, the piezoelectric ceramic product can use the inverse piezoelectric effect to work. For example, the piezoelectric ceramic product can be a buzzer. At this time, the external power supply can be connected to the piezoelectric ceramic sheet 1 through the first lead 5 and the second lead 6. When a high-frequency alternating current signal is input, the piezoelectric ceramic sheet 1 generates corresponding and regular geometric deformation due to the piezoelectric effect, and drives the metal substrate 2 to vibrate together to generate sound.

When charged, piezoelectric ceramics have natural properties that are sensitive to damp-heat conditions. Under high-temperature and high-humidity conditions, damp-heat stress defects are more likely to occur, resulting in failure of piezoelectric ceramics. Specifically, as shown in FIG. 1 , the peripheral wall of the piezoelectric ceramic sheet 1 is exposed to the environment. Under humid conditions, condensation may occur on the peripheral wall of the piezoelectric ceramic sheet 1, and water vapor may penetrate into the interior of the piezoelectric ceramic sheet 1 through the peripheral wall. As a result, the piezoelectric ceramic sheet 1 may be damaged.

In addition, the first silver paste layer 3 disposed on the upper surface of the piezoelectric ceramic sheet 1 is generally dense and waterproof, and cannot completely prevent the intrusion of water vapor. Electrical ceramic breakdown failure.

As shown in FIG. 1 , the first silver paste layer 3 is connected to the second lead 6 by welding (the bumps on the first silver paste layer 3 in FIG. 1 are welding points). Layer 3 causes damage, moisture is easily immersed into the interior of the piezoelectric ceramic sheet 1 through the welding point, and the high temperature during welding is also likely to introduce a large thermal stress to the piezoelectric ceramic sheet 1, which may cause potential damage to the ceramic sheet and bring reliability. sexual risk.

In addition, under the action of water vapor, the first silver paste layer 3 disposed on the upper surface of the piezoelectric ceramic sheet 1 is likely to migrate, resulting in a short circuit between the first silver paste layer 3 and the second silver paste layer 4 .

To sum up, the existing piezoelectric ceramic products have insufficient waterproof performance, and the piezoelectric ceramic sheets are easily attacked by water vapor and cause self-breakdown failure, thereby reducing the reliability of the product and shortening the working life of the product.

In view of the above problems, the embodiments of the present application provide a piezoelectric ceramic waterproof structure, a piezoelectric ceramic device, and an electronic device, which can enhance the waterproof performance of the piezoelectric ceramic, so that the piezoelectric ceramic product has good use reliability under humid and heat conditions. .

In the first aspect, the embodiment of the present application first provides a piezoelectric ceramic waterproof structure. FIG. 2 is a schematic structural diagram of the piezoelectric ceramic waterproof structure 10 provided by the embodiment of the present application, and FIG. 3 is the piezoelectric ceramic waterproof structure shown in FIG. 2 . 10 is a cross-sectional view of the A-A section, and FIG. 4 is a cross-sectional view of the B-B section of the piezoelectric ceramic waterproof structure 10 shown in FIG. 2 .

As shown in FIGS. 2-4 , the piezoelectric ceramic waterproof structure 10 provided in the embodiment of the present application includes a conductive substrate 11 , a piezoelectric ceramic sheet 12 , an insulating waterproof sealing member 13 and a conductive waterproof sealing member 14 .

The conductive substrate 11 has a sheet-like structure and is used to mount the piezoelectric ceramic sheet 12 , and can support and protect the piezoelectric ceramic sheet 12 . The conductive substrate 11 is made of conductive material and can conduct electricity, and the piezoelectric ceramic waterproof structure 10 can be electrically drawn out through the conductive substrate 11 .

Optionally, the conductive material includes, but is not limited to, conductive metal, conductive ceramic, conductive resin, conductive graphite, and the like.

For example, the conductive metal may be copper, stainless steel, aluminum, or nickel, or the like. At this time, the conductive substrate 11 may be a copper substrate, a stainless steel substrate, an aluminum substrate, a nickel substrate, or the like.

As shown in FIG. 3 and FIG. 4 , in the embodiment of the present application, the conductive substrate 11 is in the shape of a circle. Any regular or irregular shape is not limited in this application.

The piezoelectric ceramic sheet 12 has a sheet-like structure, is stacked on the conductive substrate 11, and maintains electrical connection therebetween.

Specifically, the piezoelectric ceramic sheet 12 includes a first connection surface and a second connection surface disposed oppositely (ie, the lower side and the upper side of the piezoelectric ceramic sheet 12 in FIG. 2 ), and the first connection surface is fixedly attached to the conductive substrate 11 superior. The piezoelectric ceramic sheet 12 is electrically connected to the conductive substrate 11, so that the conductive substrate 11, as a lead-out electrode of the piezoelectric ceramic sheet 12, can be electrically connected to an external device (such as a processor) through the conductive substrate 11, so as to realize electrical connection. lead out.

Optionally, the material of the piezoelectric ceramic sheet 12 can be any one or more of barium titanate, lead titanate, lead zirconate titanate, titanium magnesium niobate, potassium sodium niobate or ternary piezoelectric ceramics. kind.

Optionally, the piezoelectric ceramic sheet 12 may be fixedly adhered to the conductive substrate 11 by conductive glue.

As shown in FIG. 3 and FIG. 4 , in the embodiment of the present application, the shape of the piezoelectric ceramic sheet 12 is the same as the shape of the conductive substrate 11 , both of which are circular. In other embodiments, the shape of the piezoelectric ceramic sheet 12 and The shape of the conductive substrate 11 may also be different, which is not limited in this application.

Optionally, the piezoelectric ceramic sheet 12 can also be set in a rectangular, trapezoidal, rhombus, racetrack, triangular or any regular or irregular shape according to specific requirements, which is not limited in this application.

The insulating waterproof sealing member 13 has a ring structure and is sleeved on the outer periphery of the piezoelectric ceramic sheet 12 .

The conductive waterproof seal 14 is hermetically connected to the other end (ie, the upper end in FIG. 2 ) of the insulating waterproof seal 13 , so as to seal the piezoelectric ceramic sheet 12 to the conductive substrate 11 , the insulating waterproof seal 13 and the conductive waterproof seal 14 . The conductive waterproof seal 14 is electrically connected to the second connection surface to realize electrical extraction.

Specifically, as shown in FIG. 2 and FIG. 3 , the insulating waterproof sealing member 13 is in a closed annular structure, and is arranged around the outer circumference of the piezoelectric ceramic sheet 12 , and the bottom end of the insulating waterproof sealing member 13 is sealed with the conductive substrate 11 . The front end is sealed and connected with the conductive waterproof seal 14 disposed on the second connection surface, and then the piezoelectric ceramic sheet 12 is sealed in the sealing cavity enclosed by the conductive substrate 11 , the insulating waterproof seal 13 and the conductive waterproof seal 14 In the body, the insulating waterproof sealing member 13 and the conductive waterproof sealing member 14 are made of waterproof materials, and the water vapor cannot penetrate the insulating waterproof sealing member 13 and the conductive waterproof sealing member 14 and cause the piezoelectric ceramic sheet 12 to invade.

Further, the conductive waterproof seal 14 is made of a conductive material, can conduct electricity, and is electrically connected to the second connection surface. In this way, the conductive waterproof seal 14 can be used as another lead-out electrode of the piezoelectric ceramic waterproof structure 10, thereby enabling the pressure Electrical lead-out of the electric ceramic waterproof structure 10 .

The insulating waterproof sealing member 13 is made of insulating material and cannot conduct electricity. In this way, the conductive waterproof sealing member 14 and the conductive substrate 11 can be effectively electrically isolated to prevent a short circuit between them.

According to the piezoelectric ceramic waterproof structure 10 provided in the embodiment of the present application, the piezoelectric ceramic sheet 12 is sealed in the sealed cavity enclosed by the conductive substrate 11 , the insulating waterproof sealing member 13 and the conductive waterproof sealing member 14 , which can effectively isolate the water vapor. , so that the resistance of the piezoelectric ceramic sheet 12 to water vapor is significantly improved. On the one hand, the market failure rate of the piezoelectric ceramic waterproof structure 10 in normal use can be reduced, the stability of the product can be effectively improved, and the user experience can be improved. On the other hand, since the reliability of the piezoelectric ceramic waterproof structure 10 is improved, the product can work under a higher field strength, so that better working performance, such as amplitude, etc., can be obtained. Tests have verified that the piezoelectric ceramic waterproof structure 10 provided in the embodiment of the present application can achieve good reliability results under high temperature and high humidity conditions, ensuring that the product can work reliably under severe conditions of high temperature and high humidity, and has a low failure rate.

Here, the conductive substrate 11 and the conductive waterproof seal 14 are electrically connected to the piezoelectric ceramic sheet 12, respectively, and the electrical signal (induction signal) generated by the deformation of the piezoelectric ceramic sheet 12 can be output to an external device (such as a processor through the above two) ), the external high-frequency alternating current can also be applied to the piezoelectric ceramic sheet 12 through the above two to make it deform and emit sound.

The insulating waterproof seal 13 is made of a material with insulating and waterproof properties, which is not limited in this application, for example, the material may be rubber, plastic, or resin.

Optionally, the insulating waterproof seal 13 may be composed of insulating waterproof glue.

Alternatively, the insulating waterproof seal 13 may also be composed of an insulating film.

Alternatively, the insulating film may be formed on the peripheral side and the upper side of the piezoelectric ceramic sheet 12 by an evaporation process. At this time, the insulating film may also be referred to as evaporation coating or vacuum coating.

Optionally, the conductive waterproof seal 14 may be composed of conductive waterproof glue. The conductive waterproof glue can be formed by filling a certain concentration of conductive particles into the adhesive.

Alternatively, the conductive waterproof seal 14 may be constructed of conductive metal.

For example, the conductive waterproof seal 14 may be formed from evaporated or sputtered dense conductive metal. The conductive metal may be copper, aluminum, silver, or the like.

As shown in FIG. 2 , in the embodiment of the present application, the piezoelectric ceramic waterproof structure 10 further includes a first conductive connection layer 18 , and the first connection surface is electrically connected to the conductive substrate 11 through the first conductive connection layer 18 .

Similarly, in the embodiment of the present application, the piezoelectric ceramic waterproof structure 10 further includes a second conductive connection layer 19 , and the conductive waterproof seal 14 is electrically connected to the second connection surface through the second conductive connection layer 19 .

Specifically, an electrode layer (the electrode layer is also called an electrode) needs to be respectively provided on the upper and lower surfaces (ie, the first connection surface and the second connection surface) of the piezoelectric ceramic sheet 12 to realize internal polarization, thereby enabling Realize piezoelectric effect or inverse piezoelectric effect.

In the embodiment of the present application, the first conductive connection layer 18 and the second conductive connection layer 19 may be respectively fixed on the upper and lower surfaces of the piezoelectric ceramic sheet 12 as electrode layers (electrodes). At this time, the piezoelectric ceramic sheet 12 can be fixedly attached to the conductive substrate 11 through the first conductive connection layer 18 (eg, bonded by conductive glue), and maintain electrical connection with the conductive substrate 11 . The conductive waterproof sealing member 14 can be connected on the second conductive connection layer 19 , and is electrically connected to the piezoelectric ceramic sheet 12 through the second conductive connection layer 19 .

Optionally, the first conductive connection layer 18 and/or the second conductive connection layer 19 may be a metal thin film, and the metal may be silver, copper, gold, nickel, palladium, platinum, or the like.

For example, the first conductive connection layer 18 and/or the second conductive connection layer 19 may be a silver paste layer. The thickness of the silver paste layer may be 20-50 microns.

If the thickness of the silver paste layer is too thin, the piezoelectric ceramic sheet 12 will be insufficiently covered with silver, and the reliability cannot be guaranteed; if the thickness of the silver paste layer is too thick, the cost will be greatly increased. In the embodiment of the present application, the thickness of the silver paste layer Choosing 20-50 microns (eg 25, 30, 35, 40 or 45 microns) can ensure the reliability of piezoelectric ceramics and take into account the cost requirements.

Optionally, the first conductive connection layer 18 and the second conductive connection layer 19 may be disposed on the piezoelectric ceramic sheet 12 through processes such as sintering, vacuum evaporation, chemical deposition, and the like.

As shown in FIGS. 2-4 , the insulating waterproof sealing member 13 includes a sealing ring 13a and a sealing eaves 13b which are connected to each other. The sealing ring 13a is sleeved on the outer periphery of the piezoelectric ceramic sheet 12, one end is sealedly connected to the conductive substrate 11, and the other end is connected to the sealing eaves 13b. The sealing eaves 13b extend inward from the edge of the second connection surface (the center position of the piezoelectric ceramic sheet 12 ), and the front end is sealedly connected to the conductive waterproof seal 14 .

In the embodiment of the present application, the sealing eaves 13b are provided, so that the connection between the insulating waterproof sealing member 13 and the conductive waterproof sealing member 14 is located inside the projection of the piezoelectric ceramic sheet 12 rather than at the edge, thereby improving the reliability of the sealing connection.

As shown in FIG. 2 and FIG. 3 , the sealing ring 13 a is arranged around the outer periphery of the piezoelectric ceramic sheet 12 and is attached to the peripheral wall of the piezoelectric ceramic sheet 12 , and the sealing eaves 13 b are attached to the second conductive connection layer 19 , the conductive waterproof sealing member 14 is stacked on the sealing eaves 13b. At this time, the insulating waterproof seal 13 can be an insulating waterproof glue, the conductive waterproof seal 14 can be a conductive waterproof glue, and the insulating waterproof glue and the conductive waterproof glue overlap each other to ensure the waterproof performance above the piezoelectric ceramic sheet 12 .

As shown in FIG. 2 and FIG. 4 , the sealing eave 13b has an annular structure with a through hole formed inside, the conductive waterproof sealing member 14 is attached to the sealing eave 13b, and the middle of the conductive waterproof sealing member 14 protrudes from the through hole, And it is electrically connected to the second conductive connection layer 19 . Through the above arrangement, the conductive waterproof sealing member 14 can be reliably pressed on the sealing eaves 13b, so as to realize the reliability of the sealing connection between the two.

Specifically, the conductive waterproof seal 14 has an inverted “convex” structure, including a main body portion 14a and a protruding portion 14b that are connected to each other. The through hole is connected to the second conductive connection layer 19, and the edge portion of the main body portion 14a is press-fitted on the sealing eaves 13b, so as to realize the reliability of the sealing connection between the two.

As shown in FIG. 2 , the conductive waterproof seal 14 is stacked on the sealing eaves 13b. In other embodiments, the positions of the two can also be exchanged, and the sealing eaves 13b can be stacked on the conductive waterproof seal 14. The protruding portion of the waterproof seal 14 protrudes out of the through hole and is electrically connected to the external device, thereby enabling electrical extraction.

The following describes how the piezoelectric ceramic waterproof structure 10 provided by the embodiments of the present application realizes electrical extraction with reference to the accompanying drawings.

As shown in FIGS. 2-4 , the piezoelectric ceramic waterproof structure 10 further includes a circuit board 15 and a first conductive foam structure 16 , and the conductive waterproof seal 14 is electrically connected to the circuit board 15 through the first conductive foam structure 16 . .

Specifically, a first conductive foam structure 16 may be disposed between the circuit board 15 and the conductive waterproof seal 14 , and two sides of the first conductive foam structure 16 are respectively crimped to between the circuit board 15 and the conductive waterproof seal 14 . On the other hand, a reliable electrical connection is achieved, thereby realizing the electrical extraction of the piezoelectric ceramic waterproof structure 10 .

In the embodiment of the present application, by setting the first conductive foam structure 16 and the conductive waterproof sealing member 14 to be crimped, the welding stress introduced by using the traditional welding method is avoided, and the cracks of the piezoelectric ceramics caused by the welding stress are eliminated, thereby improving the product. reliability and production consistency. In addition, the conductive foam has a certain degree of flexibility, and the configuration of the conductive foam will not hinder the deformation of the piezoelectric ceramic sheet 12, thereby ensuring the piezoelectric ceramic waterproof structure 10 to have reliable working performance.

Alternatively, the circuit board 15 may be a printed circuit board (PCB).

Optionally, the circuit board 15 may be a flexible board, a rigid board or a flexible-rigid combination board.

For example, the circuit board 15 may be a flexible printed circuit (FPC). The flexible circuit board is a highly reliable and excellent flexible printed circuit board made of polyimide or polyester film. It has the characteristics of high wiring density, light weight, thin thickness and good bendability.

Optionally, in other embodiments, the electrical connection between the conductive waterproof seal 14 and the circuit board 15 may also be achieved in other ways, which is not limited in this application. For example, the two can be electrically connected through wires, or through other flexible conductive materials, or the two can be directly connected. In this case, the conductive waterproof seal 14 can be directly bonded to the surface of the circuit board 15 .

As shown in FIGS. 2-4 , the piezoelectric ceramic waterproof structure 10 further includes a second conductive foam structure 17 , and the conductive substrate 11 is electrically connected to the circuit board 15 through the second conductive foam structure 17 .

Further, the second conductive foam structure 17 is a ring-shaped structure, and is sleeved on the outer periphery of the insulating waterproof seal 13. There may be a gap between the second conductive foam structure 17 and the insulating waterproof seal 13, and the second conductive foam One end of the structure 17 is electrically connected to the conductive substrate 11 , and the other end is electrically connected to the circuit board 15 .

FIG. 5 is a schematic structural diagram of another example of the piezoelectric ceramic waterproof structure 10 provided by the embodiment of the present application.

As shown in FIG. 5 , compared with the embodiments shown in the aforementioned FIGS. 2 to 4 , in this embodiment, the conductive waterproof sealing member 14 has a “convex” shape, and the bottom is attached to the second conductive connection layer 19 The sealing eave 13b is stacked on the conductive waterproof sealing member 14, and the protruding part of the conductive waterproof sealing member 14 protrudes from the through hole in the middle of the sealing eave 13b and is closely attached to the first conductive foam structure 16 to realize electrical connection, and then Electrical extraction can be achieved.

On the other hand, the embodiment of the present application further provides a piezoelectric ceramic device, and FIG. 6 is a schematic structural diagram of the piezoelectric ceramic device 100 provided by the embodiment of the present application. As shown in FIG. 6 , the piezoelectric ceramic device 100 includes a processor 20 and at least one piezoelectric ceramic waterproof structure 10 provided in any of the foregoing embodiments. The processor 20 is electrically connected to the piezoelectric ceramic waterproof structure 10 .

Optionally, the piezoelectric ceramic device 100 can work by utilizing the positive piezoelectric effect of the piezoelectric ceramic, and at this time, the processor 20 can receive and process the electrical signal generated by the piezoelectric ceramic waterproof structure 10 . For example, the piezoelectric ceramic device 100 may be a piezoelectric sensor (touch sensor), a pressure sensor, an acceleration sensor, or a gyroscope.

Optionally, the piezoelectric ceramic device 100 can also work by utilizing the inverse piezoelectric effect of the piezoelectric ceramic, and at this time, the processor 20 can input a driving current (such as high-frequency alternating current) to the piezoelectric ceramic waterproof structure 10 . For example, the piezoelectric ceramic device 100 may be a buzzer, an ultrasonic transducer, an underwater acoustic transducer, a filter, a resonator, or the like.

In another aspect, an embodiment of the present application further provides an electronic device, and FIG. 7 is a schematic structural diagram of an electronic device 1000 provided by an embodiment of the present application. As shown in FIG. 7 , the electronic device 1000 provided by the embodiment of the present application includes the piezoelectric ceramic device 100 provided by the foregoing embodiment.

As shown in FIG. 6 and FIG. 7 , in this embodiment of the present application, the electronic device 1000 is a notebook computer, including a touch panel 200 . The piezoelectric ceramic device 100 is a piezoelectric sensor, and includes a plurality of piezoelectric ceramic waterproof structures 10 , and the plurality of piezoelectric ceramic waterproof structures 10 are arranged in an array inside the touch panel 200 .

When in use, the user can provide a pressing signal to the piezoelectric sensor by pressing the touchpad 200. At this time, the piezoelectric ceramic sheet 12 is deformed to generate an electrical signal inside, and the electrical signal is transmitted to the processor 20 through the circuit board 15, and the processor 20 can The control command input by the user is determined according to the electrical signal.

Further, the processor 20 may also be configured to generate a driving current to drive the piezoelectric sensor to generate vibration after receiving the electrical signal generated by the piezoelectric sensor, so that the user can perceive the vibration through the touch panel 200 . Feeding back the vibration to the user is beneficial to reduce the occurrence of the virtual pressing problem, which can improve the user experience.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited to this. should be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

A piezoelectric ceramic waterproof structure, comprising:

a conductive substrate (11);

A piezoelectric ceramic sheet (12), comprising a first connection surface and a second connection surface arranged opposite to each other, and the first connection surface is fixedly attached to the conductive substrate (11);

an insulating waterproof sealing member (13), in the form of a ring structure, sleeved on the outer periphery of the piezoelectric ceramic sheet (12), and one end of the insulating waterproof sealing member (13) is sealedly connected with the conductive substrate (11);

A conductive waterproof seal (14) is sealedly connected to the other end of the insulating waterproof seal (13), so as to seal the piezoelectric ceramic sheet (12) on the conductive substrate (11), and the insulating waterproof seal The conductive waterproof sealing member (14) and the sealing cavity enclosed by the conductive waterproof sealing member (14) are electrically connected to the second connection surface.
The piezoelectric ceramic waterproof structure according to claim 1, wherein the insulating waterproof sealing member (13) comprises a sealing ring (13a) and a sealing eaves (13b) which are connected to each other;

The sealing ring (13a) is sleeved on the outer periphery of the piezoelectric ceramic sheet (12), one end is sealedly connected to the conductive substrate (11), and the other end is connected to the sealing eaves (13b);

The sealing eave (13b) extends inward from the edge of the second connection surface, and the front end is sealedly connected with the conductive waterproof seal (14).
The piezoelectric ceramic waterproof structure according to claim 2, characterized in that, the sealing eave (13b) has a ring-shaped structure with a through hole formed therein, and the conductive waterproof sealing member (14) is attached to the sealing eave (13b). 13b), the middle part of the conductive waterproof seal (14) protrudes out of the through hole, and is electrically connected to the second connection surface.
The piezoelectric ceramic waterproof structure according to any one of claims 1-3, wherein the piezoelectric ceramic waterproof structure further comprises a circuit board (15) and a first conductive foam structure (16), the The conductive waterproof seal (14) is electrically connected to the circuit board (15) through the first conductive foam structure (16).
The piezoelectric ceramic waterproof structure according to claim 4, wherein the piezoelectric ceramic waterproof structure further comprises a second conductive foam structure (17), and the conductive substrate (11) passes through the second conductive foam The cotton structure (17) is electrically connected to the circuit board (15).
The piezoelectric ceramic waterproof structure according to claim 5, characterized in that the second conductive foam structure (17) is in the form of an annular structure, and is sleeved on the outer periphery of the insulating waterproof sealing member (13), and the One end of the second conductive foam structure (17) is electrically connected to the conductive substrate (11), and the other end is electrically connected to the circuit board (15).
The piezoelectric ceramic waterproof structure according to any one of claims 1-3, characterized in that, the piezoelectric ceramic waterproof structure further comprises a first conductive connection layer (18), and the first connection surface passes through the The first conductive connection layer (18) is electrically connected to the conductive substrate (11).
The piezoelectric ceramic waterproof structure according to any one of claims 1-3, wherein the piezoelectric ceramic waterproof structure further comprises a second conductive connection layer (19), and the conductive waterproof seal (14) It is electrically connected to the second connection surface through the second conductive connection layer (19).
The piezoelectric ceramic waterproof structure according to any one of claims 1-3, wherein the insulating waterproof sealing member (13) is composed of insulating waterproof glue or insulating film.
The piezoelectric ceramic waterproof structure according to any one of claims 1-3, characterized in that, the conductive waterproof seal (14) is made of conductive waterproof glue or conductive metal.
The piezoelectric ceramic waterproof structure according to claim 4, wherein the circuit board (15) comprises a flexible circuit board.
A piezoelectric ceramic device, characterized by comprising a processor and the piezoelectric ceramic waterproof structure according to any one of claims 1-11, wherein the processor is electrically connected to the piezoelectric ceramic waterproof structure.
An electronic device, characterized by comprising the piezoelectric ceramic device according to claim 12 .