Vibration device structure

Abstract

The invention relates to a vibration device structure which comprises the following structures: a shell which is provided with a base arranged along the width direction of the shell and an internal cavity; the vibration element is fixed on the base and covers the internal cavity, and a gap exists in the edge close to the length direction of the shell, namely, the width of the vibration element is smaller than that of the shell; the vibration element is provided with a metal substrate, a plurality of layers of piezoelectric ceramic pieces, an FPC connector and a protruding block which are sequentially stacked from bottom to top. A through hole is formed in the center of the cover body, the cover body seals the vibration element in the shell, and the convex block is exposed out of the through hole; the through hole is communicated with the inner cavity; the thickness T of the metal substrate is 0.1 to 0.3 mm; a half L of the length difference between the multilayer piezoelectric ceramic piece and the metal substrate is in a range of 1-2.8 mm; the vibration device structure can bear at least 60 N pressure, and the acceleration of the whole product is larger than that of an existing design.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure-sensitive devices, and in particular to a vibration device structure. Background Art

[0002] In the case of pressure-sensitive screens, artificially generated tactile feedback is desirable when pressing a virtual keyboard in order to improve operability. This is particularly important in the automotive sector, since there the user cannot permanently focus on the screen. Tactile feedback can be used, for example, to inform the user that the setting executed by him was successfully implemented. However, existing devices for generating tactile feedback are usually very complex and have inefficient conversion.

[0003] The vibration device in the prior art is as follows Figure 1 As shown, the structure is a piezoelectric ceramic bonded between two cymbals. The defect of this design is that when the product is subjected to a drop test, the ceramic in the middle will be squeezed by the cymbals on both sides and will be broken; in addition, it cannot meet the closed requirements. For some special usage environments, such as when the terminal product needs to be closed inside (the terminal product needs to be potted inside), in this case, the product also needs to be sealed. Otherwise, when the product is potted, the glue will bond the metal sheet and ceramic and fix it, causing the product to be unable to vibrate, resulting in the product performance failing to meet customer needs; and finally, the acceleration is not ideal. Summary of the invention

[0004] In order to solve the above technical problems, a vibration device structure is provided. The vibration device structure of the present invention will not cause the ceramic sheet to be crushed by the metal sheet during the drop test, and the glue filling process has no effect on the structure of the present invention, and the acceleration of the structure of the present invention is better.

[0005] In order to achieve the above effects, the present invention is implemented through the following technical solutions:

[0006] A vibration device structure, comprising the following structure:

[0007] A shell having a base arranged along the width direction of the shell and an internal cavity;

[0008] A vibration element, wherein the vibration element is fixed on the base and covers the internal cavity, and there is a gap near the edge of the length direction of the shell, that is, the vibration element does not completely cover the internal cavity, but leaves a gap at the edge of the length direction of the shell, that is, the width of the vibration element is smaller than the width of the shell. If the vibration element completely covers the internal cavity, it will affect the acceleration of the product and generate noise; the vibration element is stacked from bottom to top in sequence and includes: a metal substrate, a multilayer piezoelectric ceramic sheet, an FPC connector and a bump;

[0009] A cover body, wherein the center of the cover body has a through hole, the cover body seals the vibration element in the housing and the protrusion is exposed from the through hole; the through hole is connected to the internal cavity;

[0010] The thickness T of the metal substrate is 0.1-0.3mm; the half of the length difference L between the multilayer piezoelectric ceramic sheet and the metal substrate is in the range of 1-3mm. These two parameters are closely related to the acceleration of the overall product. The larger the overall product, the greater the acceleration; the thinner the metal substrate T, the greater the overall product acceleration; the greater the half of the length difference L between the metal substrate and the multilayer piezoelectric ceramic sheet, the greater the product acceleration. Under the condition of the same size, the overall product designed by the present invention has a better acceleration than the prior art.

[0011] Further, the diameter of the protrusion is smaller than the diameter of the through hole, the diameter of the protrusion is 1.5-2.5 mm, and the height is at least 0.5 mm; the height of the protrusion protruding from the cover body is at least 0.05 mm, preferably the height of the protrusion protruding from the cover body is 0.1 mm;

[0012] Furthermore, the material of the bump is silicone rubber, and its Rockwell hardness HRC is at least 85, and preferably its Rockwell hardness HRC is 95±5. Too low hardness (ie soft) will absorb the acceleration generated by the vibration of the ceramic, resulting in a smaller acceleration of the product.

[0013] Furthermore, the structure of the multilayer piezoelectric ceramic sheet is: comprising a plurality of internal electrodes and a plurality of ceramic sheets alternately stacked, and a plurality of the ceramic sheets stack a plurality of the internal electrodes therein, and the number of the ceramic sheets is one more than the number of the internal electrodes;

[0014] The side of the multilayer piezoelectric ceramic sheet has two inner electrodes that are not in contact with each other, and the inner electrodes are divided into positive and negative electrodes. The upper surface of the multilayer piezoelectric ceramic sheet has a silver electrode that is conductive to the inner electrode. The specific structure of the multilayer piezoelectric ceramic sheet is shown in CN117762249A.

[0015] Furthermore, the metal substrate is snapped and / or bonded to the base of the shell, the multilayer piezoelectric ceramic sheet is bonded to the metal substrate using UV anaerobic adhesive or epoxy adhesive, the FPC connector is located on the upper surface of the multilayer piezoelectric ceramic sheet and forms a circuit connection with it, and the bump is bonded to the upper surface of the FPC connector.

[0016] Furthermore, the positive electrode of the FPC connector is welded to the positive electrode of the multilayer piezoelectric ceramic sheet, the negative electrode of the FPC connector is welded to the negative electrode of the multilayer piezoelectric ceramic sheet, and then the ACF process is used to form a circuit connection between the FPC connector and the multilayer piezoelectric ceramic sheet.

[0017] Furthermore, an edge of the shell in a length direction has a recess, and a hole is formed in the recess after the shell and the cover are closed, and the hole is used to lead out the leads of the FPC connector.

[0018] Furthermore, the height of the base is greater than 0.1 mm, preferably within the range of 0.1-0.3 mm. The height needs to be greater than the deformation of the vibration element, and the maximum downward displacement deformation of the vibration element does not exceed 100 μm.

[0019] Beneficial technical effects: The vibration device structure of the present invention includes a shell, a cover and a vibration element. The vibration element is assembled in sequence by a metal substrate, a ceramic sheet, an FPC connector and a bump. The vibration element is located on the base of the shell, and the vibration element is not in contact with the shell in the length direction, and the bump protrudes from the hole in the cover. When the structure is energized (connected to the lead wire of the FPC and energized), the electrons cause the vibration element to generate bending deformation vibration, driving the bump on its upper part to vibrate up and down. Under the same size, the acceleration of the product of the present invention is better than the prior art. The metal substrate is located below the ceramic sheet, and the protective effect of the shell and the cover will not have an adverse effect on the ceramic sheet when it falls or bends. In addition, the shell and the cover can wrap the vibration element, and the through-hole part is connected to the internal cavity, which will not affect the vibration and acceleration of the product, and the shell and the cover can protect the vibration element. The vibration energy of the vibration element is transmitted through the bump on the product, and the vibration force of the entire product is transmitted to the client product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 An exploded view of the structure of the vibration device of the present invention;

[0021] Figure 2 It is a schematic diagram of the cross-sectional structure of the vibration device of the present invention;

[0022] 11-housing, 111-base, 12-cover, 2-metal substrate, 3-multilayer piezoelectric ceramic sheet, 4-FPC connector, 5-bump;

[0023] Figure 3 This is an acceleration curve diagram of the vibration device structure of Example 1. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in combination with the embodiments of the present invention and the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention are within the scope of protection of the present invention.

[0025] Unless otherwise specifically stated, the numerical value set forth in these embodiments does not limit the scope of the present invention. The technology and method known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology and method should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0026] The experimental methods in the following examples without specifying specific conditions are usually measured in accordance with national standards; if there is no corresponding national standard, the method is carried out in accordance with the general standard requirements or general methods.

[0027] Example 1

[0028] A vibration device structure, the structure explosion diagram is as follows Figure 1 As shown, the structural cross section is Figure 2 As shown, it includes the following structure:

[0029] The housing 11 (dimensions L×W×H=10 mm×5 mm×1.85 mm) has a base 111 arranged along the width direction of the housing 11 and an internal cavity;

[0030] A vibration element, the vibration element is fixed on the base 111 and covers the internal cavity, and there is a gap near the edge of the length direction of the shell 11, that is, the vibration element does not completely cover the internal cavity, but leaves a gap at the edge of the length direction of the shell; the vibration element is stacked from bottom to top and includes: a metal substrate 2 (made of copper, with dimensions of length×width×thickness=9.2mm×3.5mm×0.2mm), a multilayer piezoelectric ceramic sheet 3 (dimensions of length×width×thickness=5mm×3.5mm×0.25mm, and the ceramic material is PZT), an FPC connector 4 (the pad spacing is within the range of 0.5-0.8mm, which can be changed according to requirements. In this case, the pad spacing is 0.65mm) and a bump 5 (diameter 2mm, height 0.6mm, made of silicone rubber, HRC 95±5);

[0031] A cover 12 (thickness 0.3 mm), the cover 12 having a through hole (diameter 2.5 mm) in the center, the cover 12 encloses the vibration element in the housing 11 and the projection 5 is exposed from the through hole; the through hole is connected to the internal cavity; the projection 5 protrudes from the cover 12 by a height of 0.1 mm;

[0032] In this case, the thickness of the metal substrate 2 is T=0.2 mm; half of the length difference between the multilayer piezoelectric ceramic sheet 3 and the metal substrate 2 is L=2.1 mm;

[0033] The structure of the multilayer piezoelectric ceramic sheet 3 is as follows: multiple internal electrodes and multiple ceramic sheets are alternately stacked, and multiple ceramic sheets stack multiple internal electrodes inside, and the number of ceramic sheets is one more than the number of internal electrodes; the side of the multilayer piezoelectric ceramic sheet 5 has two non-contacting left and right parts of the internal electrodes, and the internal electrodes are divided into positive and negative electrodes. The upper surface ceramic of the multilayer piezoelectric ceramic sheet 3 has a silver electrode that is conductive to the internal electrode. The specific structure of the multilayer piezoelectric ceramic sheet is shown in CN117762249A;

[0034] The metal substrate 2 is clamped and fixedly bonded to the base 111 of the housing 11, the multilayer piezoelectric ceramic sheet 3 is bonded to the metal substrate 2 by epoxy adhesive, the FPC connector 4 is located on the upper surface of the multilayer piezoelectric ceramic sheet 3, and the bump 5 is bonded to the upper surface of the FPC connector; the positive electrode of the FPC connector 4 is welded to the positive electrode of the multilayer piezoelectric ceramic sheet 3, the negative electrode of the FPC connector 4 is welded to the negative electrode of the multilayer piezoelectric ceramic sheet 3, and the ACF process is then used to form a circuit connection between the FPC connector 4 and the multilayer piezoelectric ceramic sheet 3;

[0035] In addition, an edge of the shell 11 in a longitudinal direction has a recess, and a hole is formed in the recess after the shell 11 and the cover body 12 are closed, and the hole is used to lead out the lead wires of the FPC connector 4.

[0036] Example 2

[0037] The structure of the vibration device in this case is the same as that in Example 1, except that the thickness T of the metal substrate 2 is 0.3 mm; the length of the multilayer piezoelectric ceramic sheet 3 is 6 mm; and half of the length difference L between the multilayer piezoelectric ceramic sheet 3 and the metal substrate 2 is 1.6 mm.

[0038] Example 3

[0039] The structure of the vibration device in this case is the same as that in Example 1, except that the thickness T of the metal substrate 2 is 0.15 mm; the length of the multilayer piezoelectric ceramic sheet 3 is 4 mm; and half of the length difference L between the multilayer piezoelectric ceramic sheet 3 and the metal substrate 2 is 2.6 mm.

[0040] Comparative Example 1

[0041] The structure of the vibration device in this case is the same as that in Example 1, except that the thickness T of the metal substrate 2 is 0.4 mm; the length of the multilayer piezoelectric ceramic sheet 3 is 7.2 mm; and the half length difference L between the multilayer piezoelectric ceramic sheet 3 and the metal substrate 2 is 1 mm.

[0042] Comparative Example 2

[0043] The structure of the vibration device in this case is the same as that in Example 1, except that the thickness T of the metal substrate 2 is 0.05 mm; the length of the multilayer piezoelectric ceramic sheet 3 is 7.2 mm; and the half length difference L between the multilayer piezoelectric ceramic sheet 3 and the metal substrate 2 is 1 mm.

[0044] Comparative Example 3

[0045] The structure of the vibration device in this case is the same as that in Example 1, except that the Rockwell hardness HRC of the bump is 80.

[0046] Test Case

[0047] 1. Mechanical properties test

[0048] The structure of the above embodiment was pressure tested by an electronic universal testing machine at a pressing rate of 40 mm / min. The results are shown in Table 1. As can be seen from Table 1, the vibration device structure of the present invention can withstand a pressure of at least 60 N. The greater the pressure bearing force, the better the result of the drop test that can be tolerated, that is, the product is not easy to break. Compared with the prior art, the vibration device structure of the present invention can maintain the structure intact in the drop test under the same conditions.

[0049] 2. Acceleration test

[0050] The structure of the above-mentioned embodiment 1 was subjected to an acceleration test. The test method was as follows: the entire product structure was fixed on the supporting bottom plate of the acceleration test instrument, the end of the accelerometer was placed on the position of the product protrusion, the weight block (20g) of the acceleration test instrument was connected to the weight block, and then the accelerometer of the instrument was powered on for testing. The results are shown in Tables 1 and Figure 3 .like Figure 3 As shown, the horizontal axis is time and the vertical axis is acceleration (in g). Figure 3It can be seen that the acceleration value of Example 1 is 1.2g, while the acceleration value of the conventional design (a structure with piezoelectric ceramics sandwiched between two cymbals) does not exceed 0.8g. Under the same design size requirements, the structure of the present invention has a higher acceleration, and the larger the acceleration value, the better the vibration sense of the device.

[0051] Table 1 Mechanical properties and acceleration values ​​of various embodiments

[0052] Maximum pressure N Acceleration g Example 1 60 1.2 Example 2 61 1.2 Example 3 59 1.3 Comparative Example 1 60 0.8 Comparative Example 2 56 0.9 Comparative Example 3 60 1.0

[0053] It can be seen from Table 1 that the thinner the metal substrate T is, the greater the acceleration of the overall product will be, but at the same time it will reduce the maximum pressure it can withstand, so the metal substrate cannot be designed to be too thin; the larger the L value, which is half of the length difference between the metal substrate and the multilayer piezoelectric ceramic sheet, the greater the product acceleration. The increase in L value means that the length of the ceramic sheet is shortened, but since the ceramic sheet needs to form a circuit connection with the FPC, the size of the ceramic sheet cannot be too small (that is, the L value cannot be too large). If the size is too small, the circuit connection may not be perfect, which will affect the transmission of electrical signals and thus affect the acceleration drop; the smaller hardness of the bump makes the bump softer, which has a negative impact on the acceleration.

[0054] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A vibration device structure, characterized in that: Includes the following structure: A shell having a base arranged along the width direction of the shell and an internal cavity; A vibration element, wherein the vibration element is fixed on the base and covers the internal cavity, and there is a gap near the edge of the shell in the length direction, that is, the width of the vibration element is smaller than the width of the shell; The vibration element is stacked in sequence from bottom to top and includes: a metal substrate, a multilayer piezoelectric ceramic sheet, an FPC connector and a bump; A cover body, wherein the center of the cover body has a through hole, the cover body seals the vibration element in the housing and the protrusion is exposed from the through hole; the through hole is connected to the internal cavity; The thickness T of the metal substrate is 0.1-0.3 mm; and the half length difference L between the multilayer piezoelectric ceramic sheet and the metal substrate is in the range of 1-3 mm.

2. A vibration device structure according to claim 1, characterized in that: The diameter of the protrusion is smaller than the diameter of the through hole, the diameter of the protrusion is 1.5-2.5 mm, and the height is at least 0.5 mm; the height of the protrusion protruding from the cover body is at least 0.05 mm.

3. A vibration device structure according to claim 2, characterized in that: The material of the bump is silicone rubber, and its Rockwell hardness HRC is at least 85.

4. A vibration device structure according to claim 2, characterized in that: The material of the bump is silicone rubber, and the structure of the multilayer piezoelectric ceramic sheet is: comprising multiple internal electrodes and multiple ceramic sheets alternately stacked, and multiple ceramic sheets stack multiple internal electrodes inside, and the number of the ceramic sheets is one more than the number of the internal electrodes; The side surface of the multilayer piezoelectric ceramic sheet has two non-contacting inner electrodes on the left and right, and the inner electrodes are divided into positive and negative electrodes. The upper surface ceramic of the multilayer piezoelectric ceramic sheet has a silver electrode that is conductive with the inner electrode.

5. A vibration device structure according to any one of claims 1 to 4, characterized in that: The metal substrate is clamped and / or bonded to the base of the shell, the multilayer piezoelectric ceramic sheet is bonded to the metal substrate using UV anaerobic adhesive or epoxy adhesive, the FPC connector is located on the upper surface of the multilayer piezoelectric ceramic sheet and forms a circuit connection with it, and the bump is bonded to the upper surface of the FPC connector.

6. A vibration device structure according to claim 5, characterized in that: The positive electrode of the FPC connector is welded to the positive electrode of the multilayer piezoelectric ceramic sheet, and the negative electrode of the FPC connector is welded to the negative electrode of the multilayer piezoelectric ceramic sheet. Then, an ACF process is used to form a circuit connection between the FPC connector and the multilayer piezoelectric ceramic sheet.

7. A vibration device structure according to claim 5, characterized in that: An edge of the shell in one length direction has a recess, and a hole is formed in the recess after the shell and the cover are closed, and the hole is used to lead out the lead of the FPC connector; the height of the base is greater than 0.1mm.

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