Anti-curl structure of piezoelectric vibrator flexible circuit board for piezoelectric micropump

Abstract

The utility model relates to the technical field of piezoelectric micro -pump especially relates to a piezoelectric vibrator flexible circuit board anti -curl structure for piezoelectric micro -pump, including piezoelectric ceramic, FPC and support layer, the FPC is single -sided copper foil structure, including insulating layer and copper foil layer, the copper foil layer is attached to piezoelectric ceramic surface, the support layer is attached to insulating layer surface to with piezoelectric ceramic clamping the FPC, the utility model discloses through setting up the FPC of single -sided copper foil structure, can when piezoelectric vibrator heating glueing solidification, reduce the difference of the deformation of the two sides of FPC due to the difference of the thermal expansion coefficient, thereby reduced the overall deformation of FPC, and, single -layer copper foil structure also reduced the stress imbalance situation when the two sides of FPC heating, thereby reduce the curl phenomenon of FPC edge, reduce the overall bending of piezoelectric vibrator, guarantee the stability of pump cavity volume change.

Description

Technical Field

[0001] This utility model relates to the technical field of piezoelectric micropumps, and in particular to an anti-curling structure for a flexible circuit board of a piezoelectric vibrator used in a piezoelectric micropump. Background Technology

[0002] Piezoelectric micropumps drive fluid movement through the periodic vibration of a piezoelectric oscillator. The core component, the piezoelectric oscillator, is typically composed of a piezoelectric ceramic sheet, a flexible printed circuit board (FPC), and a support plate stacked together. Currently, most existing piezoelectric oscillators use a double-sided copper foil structure in their FPCs. However, due to the different structures of the two copper foils, different degrees of deformation occur on both sides during the heating and curing process. This leads to significant curling at the edges of the flexible printed circuit board after cooling, resulting in overall bending and deformation of the piezoelectric oscillator. This causes problems such as unstable pump cavity volume changes, decreased fluid driving efficiency, and may even lead to cracking and failure of the piezoelectric ceramic. Utility Model Content

[0003] To address the problems mentioned above, this invention provides a piezoelectric vibrator flexible circuit board anti-curling structure for piezoelectric micropumps, which can effectively reduce the deformation of the FPC copper foil after heating and reduce the curvature of the FPC edges, thereby ensuring the stable and efficient operation of the piezoelectric micropump.

[0004] The solution adopted by this utility model to solve its technical problem is: a piezoelectric vibrator flexible circuit board anti-curling structure for piezoelectric micropumps, comprising piezoelectric ceramic, FPC and support layer stacked in sequence, wherein the FPC is a single-sided copper foil structure, including an insulating layer and a copper foil layer disposed on one side of the insulating layer, the copper foil layer is attached to the surface of the piezoelectric ceramic, and the support layer is attached to the surface of the insulating layer and clamps the FPC with the piezoelectric ceramic.

[0005] Furthermore, the FPC is provided with through holes at the positions where it adheres to the piezoelectric ceramic and the support layer for direct adhesive bonding between the piezoelectric ceramic and the support layer.

[0006] Furthermore, each surface of the piezoelectric ceramic and the copper foil layer that are in contact with each other is provided with at least one conductive electrode.

[0007] Furthermore, the coefficient of thermal expansion of the support layer is similar to that of the piezoelectric ceramic.

[0008] Furthermore, the piezoelectric ceramic is bonded to the copper foil layer, and the support layer is bonded to the insulating layer using an adhesive.

[0009] Furthermore, the adhesive is an epoxy resin adhesive.

[0010] Furthermore, the thickness of the copper foil layer is 10-36 μm, and the thickness of the insulating layer is 10-125 μm.

[0011] In summary, the beneficial effects of this utility model are as follows: 1. This utility model, by setting a single-sided copper foil structure for the FPC and bonding the copper foil layer and the insulating layer of the FPC to the piezoelectric ceramic and the support layer respectively, can reduce the difference in deformation caused by the difference in the thermal expansion coefficients of the piezoelectric ceramic and the support layer on both sides of the FPC during the heating and curing of the piezoelectric vibrator, thereby reducing the overall deformation of the FPC; in addition, the single-layer copper foil structure also reduces the stress imbalance when the two sides of the FPC are heated, thereby reducing the curling phenomenon of the FPC edge, reducing the overall bending of the piezoelectric vibrator, and ensuring the stability of the pump cavity volume change.

[0012] 2. This utility model clamps the FPC between the piezoelectric ceramic and the support layer, and provides through holes at the bonding positions of the FPC, the piezoelectric ceramic, and the support layer, so that the adhesive can directly bond the piezoelectric ceramic and the support layer through the through holes, thereby enhancing the overall bonding stability and reliability.

[0013] 3. By setting the support layer to a material with a thermal expansion coefficient similar to that of the piezoelectric ceramic, this utility model can reduce the stress between the piezoelectric ceramic and the support layer during the heating and bonding process of the piezoelectric vibrator, thereby reducing the possibility of cracking of the piezoelectric vibrator; furthermore, it can also reduce the difference in deformation between the two sides of the FPC caused by the difference in thermal expansion coefficients between the piezoelectric ceramic and the support layer, thereby further reducing the overall deformation of the FPC and ensuring the stable and efficient operation of the piezoelectric micropump.

[0014] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the piezoelectric vibrator in this embodiment; Figure 2 This is a sectional view of the stacked piezoelectric vibrator in this embodiment.

[0016] In the diagram: 1. Piezoelectric ceramic; 2. FPC; 21. Insulating layer; 22. Copper foil layer; 23. Through hole; 3. Support layer. Detailed Implementation

[0017] To make the content of this utility model easier to understand, the present utility model will be further described below with reference to specific embodiments and accompanying drawings.

[0018] It should be noted that the terms "center," "upper," "lower," "front," "rear," "left," "right," "inner," and "outer" used herein to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Unless otherwise stated, "a plurality of" means two or more.

[0019] Unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] like Figures 1 to 2 As shown, a piezoelectric vibrator flexible circuit board anti-curling structure for a piezoelectric micropump can reduce the deformation of the flexible circuit board of the piezoelectric vibrator during heating and bonding, thereby reducing the curvature of the FPC2, ensuring the structural stability of the piezoelectric vibrator, and thus improving the fluid driving efficiency of the piezoelectric micropump. The piezoelectric vibrator flexible circuit board anti-curling structure of this embodiment includes a piezoelectric ceramic 1, an FPC2, and a support layer 3 stacked sequentially. After the piezoelectric vibrator is assembled, the FPC2 can be clamped between the piezoelectric ceramic 1 and the support layer 3, allowing the FPC2 to reduce deformation under interlayer constraints, thereby reducing the deformation of the piezoelectric vibrator.

[0021] like Figure 2 As shown, the FPC2 in this embodiment is configured as a single-sided copper foil structure, including an insulating layer 21 and a copper foil layer 22 disposed on one side of the insulating layer 21. This can reduce the stress imbalance problem caused by the double-sided copper foil layer 22 in the prior art, thereby reducing the difference in deformation between the two sides of the FPC2 during heating. Furthermore, the single-sided copper foil structure can also reduce the rigidity difference of the FPC2 itself, making the overall deformation more uniform during heating and curing, thereby effectively reducing the degree of edge curling. At the same time, when the piezoelectric vibrator is heated and bonded for curing, the single-sided copper foil structure of the FPC2 can also reduce the difference in deformation between the two sides of the FPC2 caused by the difference in the thermal expansion coefficients of the piezoelectric ceramic 1 and the support layer 3, thereby further reducing the overall deformation of the FPC2, reducing the overall bending of the piezoelectric vibrator, and ensuring the stability of the pump cavity volume change.

[0022] In this embodiment, at least one conductive electrode is provided on the bottom plane of the piezoelectric ceramic 1 and the top plane of the copper foil layer 22. The side of the FPC2 with the copper foil layer 22 is attached to the bottom plane of the piezoelectric ceramic 1. When the copper foil layer 22 is attached to the bottom surface of the piezoelectric ceramic 1, the conductive electrode on the copper foil layer 22 can make close contact with the conductive electrode on the bottom surface of the piezoelectric ceramic 1, thereby forming an electrical conduction path. This ensures that the piezoelectric ceramic 1 can be connected to the driving voltage through the FPC2, thereby realizing the electrical connection between the piezoelectric ceramic 1 and the external circuit. In this embodiment, the support layer 3 is attached to the surface of the insulating layer 21 of the FPC2 and is combined with the piezoelectric ceramic 1 to form a clamping effect on the FPC2, thereby reducing the curling generated when the FPC2 is heated.

[0023] Furthermore, in this embodiment, the material of the support layer 3 is a material with a thermal expansion coefficient similar to that of the piezoelectric ceramic 1 (such as nickel-iron alloy, quartz, or ceramic). This can reduce the tensile stress on the FPC2 caused by the thermal expansion difference between the piezoelectric ceramic 1 and the support layer 3 during the heating and bonding process of the piezoelectric vibrator. This can further reduce the deformation difference between the copper foil layer 22 side and the insulating layer 21 side of the FPC2, thereby reducing the deformation of the piezoelectric vibrator.

[0024] In this embodiment, the piezoelectric ceramic 1 and the copper foil layer 22 of FPC2, as well as the support layer 3 and the insulating layer 21 of FPC2, are all bonded together with an adhesive. In this embodiment, the preferred adhesive is epoxy resin adhesive, which not only ensures good bonding strength between the piezoelectric ceramic 1 and the copper foil layer 22 of FPC2, but also ensures stable contact between the conductive electrode and the copper foil layer 22, thereby ensuring the normal operation of the piezoelectric oscillator. At the same time, it also ensures the bonding consistency between FPC2 and the support layer 3 and the piezoelectric ceramic 1, thereby ensuring the long-term stability of the interlayer connection.

[0025] like Figure 1 As shown, in order to enhance the overall connection stability of piezoelectric ceramic 1, FPC2 and support layer 3, this embodiment also provides multiple through holes 23 at the bonding positions of FPC2 with piezoelectric ceramic 1 and support layer 3. When piezoelectric ceramic 1, FPC2 and support layer 3 are bonded in sequence, the adhesive can be filled between piezoelectric ceramic 1 and support layer 3 through the through holes 23 to achieve direct bonding between the two. Thus, on the basis of the sequential bonding of the three, the overall bonding stability and reliability are further enhanced, and structural loosening caused by the failure of bonding between FPC2 and the upper and lower layers is avoided.

[0026] In addition, the thickness of the copper foil layer 22 in this embodiment is set to 10-36μm, which ensures good conductivity and avoids the problem of excessive rigidity caused by excessive thickness of the copper foil layer 22, thereby reducing the deformation of FPC2. The thickness of the insulating layer 21 in this embodiment is selected from polyimide (PI) or polyester (PET) materials with good temperature resistance and flexibility, and the thickness is set to 10-125μm. This allows FPC2 to achieve a balance between flexibility and structural strength, further reducing the tendency to curl.

[0027] In summary, this embodiment effectively reduces the curling degree of FPC2 during heating and bonding by using a single-sided copper foil FPC2 design, ensuring the overall flatness of the piezoelectric vibrator, thereby stabilizing the pump chamber volume change of the piezoelectric micropump, improving the fluid drive efficiency, and reducing the risk of cracking of the piezoelectric ceramic 1.

[0028] The embodiments described above are merely preferred embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model. Any non-substantial changes and modifications made by those skilled in the art based on this utility model shall fall within the scope of protection of this utility model.

Claims

1. A piezoelectric vibrator flexible circuit board anti-curling structure for a piezoelectric micropump, comprising a piezoelectric ceramic (1), an FPC (2), and a support layer (3) stacked sequentially, characterized in that, The FPC (2) is a single-sided copper foil structure, including an insulating layer (21) and a copper foil layer (22) disposed on one side of the insulating layer (21). The copper foil layer (22) is attached to the surface of the piezoelectric ceramic (1), and the support layer (3) is attached to the surface of the insulating layer (21) and clamps the FPC (2) with the piezoelectric ceramic (1).

2. The anti-curling structure of a flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 1, characterized in that, The FPC (2) is provided with through holes (23) at the position where it is attached to the piezoelectric ceramic (1) and the support layer (3) for direct bonding of the piezoelectric ceramic (1) and the support layer (3).

3. The anti-curling structure of the flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 1, characterized in that, The piezoelectric ceramic (1) and the copper foil layer (22) are each provided with at least one conductive electrode in contact with each other on their respective surfaces.

4. The anti-curling structure of the flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 1, characterized in that, The coefficient of thermal expansion of the support layer (3) is similar to that of the piezoelectric ceramic (1).

5. The anti-curling structure of a flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 1, characterized in that, The piezoelectric ceramic (1) and the copper foil layer (22) and the support layer (3) and the insulating layer (21) are all bonded together with adhesive.

6. The anti-curling structure of the flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 5, characterized in that, The adhesive is epoxy resin glue.

7. The anti-curling structure of the flexible circuit board for a piezoelectric vibrator used in a piezoelectric micropump according to claim 1, characterized in that, The thickness of the copper foil layer (22) is 10-36 μm, and the thickness of the insulating layer (21) is 10-125 μm.

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