TW201638469A - Miniature piezoelectric fan heat dissipation module - Google Patents

Abstract

The present invention relates to a miniature piezoelectric fan heat dissipation module, which comprises: a heat dissipation metal plate; a frame mounted on a first surface of the heat dissipation metal plate such that the height of the frame is less than 4mm; at least one side frame mounted on a lateral side of the frame to form a heat dissipation configuration with at least one predetermined opening; a flow guide plate mounted on the frame for forming an interlayer chamber with a spacing less than 4mm between the flow guide plate and the heat dissipation metal plate; and a piezoelectric cantilever blade constituted by a flexible sheet and a thin piezoelectric element mounted on a surface of the flexible sheet, and having one end fixed to a top of the frame and the other end extending forward to form a free end, wherein the free end of the piezoelectric cantilever blade is located in the interlayer chamber. As a result, when an AC voltage is applied to drive the piezoelectric cantilever blade, the piezoelectric cantilever blade performs a small-amplitude suspending vibration so as to drive or compress, in the small spacing distance of the interlayer chamber, the air inside the interlayer chamber thereby forming an airflow on a surface of a heat source to remove thermal energy from the heat dissipation metal plate and thus improve heat conduction speed.

Description

Micro piezoelectric fan cooling module

The invention relates to a miniature piezoelectric fan heat dissipation module, in particular to a structure in which a piezoelectric cantilever blade system is disposed in a sandwich chamber.

In recent years, due to the development of 3C communication, computer and living devices towards miniaturization and high functionality, the component density is very high, and the circuit line width is up to the nanometer scale, which makes the system consume energy and heat up due to high information operation. . The portable or wearable small 3C products are smaller than the previous products, and the component housing space is compact and limited.

As shown in FIG. 1 , a schematic diagram of an axial flow fan 80 is adopted. The leaf fan 81 of the axial flow fan 80 is designed to cooperate with a heat source (H) to design a venting passage, which is perpendicular to the heat source (H), and the height cannot be reduced. The heat dissipation in the limited space of the portable 3C product is not applicable, and the generated heat dissipation airflow is not easy to go tropical. Therefore, it is difficult to achieve the cooling demand. It is applied to the body components of the millimeter scale, and the conventional fan structure is difficult to effectively perform due to space limitation. Cooling.

In order to solve the above problem, in the prior art, a piezoelectric material fabrication technique has been developed to produce a sheet structure, and when an electric field is applied to the piezoelectric sheet material, mechanical deformation fan air can be generated to dissipate heat. The piezoelectric fan design is composed of a piezoelectric sheet combined with a single piece of metal blade, and the piezoelectric sheet is driven by a voltage to drive the metal blade to fan, thereby dissipating heat. However, it is checked that such a monolithic piezoelectric fan has a heat dissipation capability that is still inferior to that of the axial flow fan 80, and the components are exposed to the body and are susceptible to vibration and disturbance.

2 is a schematic view of a modified two-piece piezoelectric blade 90 having a support member 91 and two unilateral edges fixed thereto. a piezoelectric actuator assembly 92 on the support member, whereby when the piezoelectric actuator assembly 92 is loaded with an alternating voltage, the two piezoelectric actuator assemblies 92 are secured to the support member 91 by a single edge. The remaining unfixed regions of the piezoelectric actuator assembly 91 are caused to generate relative opening and closing oscillations via the alternating voltage, so that the air is sucked in and out. However, it is checked that the jet type two-piece piezoelectric leaf fan 90 has a jet flow system perpendicular to the heat source (H), and therefore still occupies space, and is not suitable for heat dissipation in a limited space of the portable 3C product, and further, With the monolithic piezoelectric fan, there are disadvantages of vibration and airflow disturbance.

The present inventors have actively studied and improved in view of the above problems, in order to overcome their shortcomings.

The main purpose of the present invention is to solve the problems of the prior art and provide a miniature piezoelectric fan heat dissipation module, which is driven by a piezoelectric fan to cool the airflow, and combines the heat dissipation heat dissipation effect of the metal composite interlayer to improve heat dissipation. The ability to reduce the capacity of the accommodating space is especially suitable for portable or wearable small 3C products.

In order to achieve the above object, the technical means adopted by the present invention comprises: a heat dissipating metal plate having a first surface, and an opposite side as a second surface contacting a predetermined heat source; at least one frame being disposed on the heat dissipating metal a first surface of the board, and the height of the frame is less than 4 mm; at least one frame is disposed on a side of the frame to form a heat dissipation configuration of a predetermined opening; a deflector is An upper portion of the frame and a sandwich chamber having a spacing of less than 4 mm between the heat dissipating metal plate; and a piezoelectric cantilever blade having a smaller area than the rectangular sheet of the frame, comprising a flexible piece and a a thin piezoelectric element on the surface of the flexible sheet, one end of which is fixed on the frame, the corresponding end extends forward to form a free end, and the free end of the piezoelectric cantilever blade is located between the interlayer chamber Therefore, when the AC voltage drives the piezoelectric cantilever blade, the piezoelectric cantilever blade is caused to vibrate with a small amplitude, thereby compressing and driving the gas in the interlayer cavity in a small space of the interlayer chamber. Forming a gas flow in a direction parallel to the surface of the heat source to thereby remove the heat energy of the heat dissipating metal plate and accelerate its heat conduction.

According to a preferred feature of the present invention, in a possible embodiment, the frame is disposed on a rear side of the frame to form the micro-piezoelectric fan heat dissipation module to form a front-side open single-port heat dissipation configuration.

In another possible embodiment, the frame is disposed on the left and right sides of the frame, so that the micro piezoelectric fan heat dissipation module forms a double-port heat dissipation configuration with front and rear lateral openings.

In another possible embodiment, the frame is disposed on the left and right sides of the side and a portion of the frame, so that the micro piezoelectric fan heat dissipation module forms a three-side heat dissipation configuration with three lateral openings. .

In another possible embodiment, the frame is disposed on the four end corners of the frame, so that the micro piezoelectric fan heat dissipation module forms a four-port heat dissipation configuration with four lateral openings.

In another possible embodiment, the frame is disposed around the periphery of the frame, and an opening is formed on the top surface of the deflector to make the micro-piezo fan cooling module form a four-sided closed heat dissipation. structure.

In a possible embodiment, the frame comprises: being fixed to the frame in a combined manner, or directly integrally formed on the frame.

By means of the above-mentioned technical means, the micro-piezoelectric fan heat-dissipating module of the invention adopts the thin and geometric characteristics of the piezoelectric fan, and combines the sandwich chamber formed by the heat-dissipating metal plate and the deflector to form an air flow that drives the surface of the heat source, and has an acceleration. The heat conduction function of the heat conduction can shield the vibration and the turbulence of the piezoelectric fan during heat dissipation. Furthermore, the present invention utilizes the design of the heat dissipation port in the sandwich chamber to meet the demand, thereby achieving the best heat dissipation efficiency.

First, referring to FIG. 3 to FIG. 9, a miniature piezoelectric fan heat dissipation module 70 of the present invention includes a heat dissipation metal plate 10 having a first surface 11 and an opposite side as a contact. The second surface 12 of the predetermined heat source 13; the heat dissipating metal plate 10 is preferably formed of a copper plate having good thermal conductivity, but is not limited thereto, and an equivalent metal or alloy may be used.

At least one frame 20 is disposed on the first surface 11 of the heat dissipation metal plate 10, and the height of the frame 20 is lower than 4 mm. In this embodiment, a rear surface of the frame 20 may be provided with a mounting surface 21, It is used for subsequent assembly, but is not limited to this.

At least one frame 30 is disposed on a side of the frame 20 to form a heat dissipation configuration of a predetermined opening. In this embodiment, the frame 30 is fixed to the frame 20 in a combined manner, but is not limited thereto. Therefore, the frame 30 can be implemented by directly forming the frame 30 on the frame 20.

A baffle 40 is disposed above the frame 20 or the frame 30 and forms a sandwich chamber 50 with the spacing (d) of less than 4 mm between the heat dissipating metal plate 10; the baffle 40 can be metal or Non-metallic materials can be used.

a piezoelectric cantilever blade 60 having a rectangular sheet having a smaller area than the frame 20, comprising a flexible sheet 61 and a thin piezoelectric element 62 disposed on a surface of a portion of the flexible sheet 61, the rear end portion of which is formed Fixed on the frame 20, and has a power cord 63, the corresponding end extends forward to form a free end, and the free end of the piezoelectric cantilever blade 60 is located between the sandwich chamber 50; as for the application of alternating current loading The piezoelectric cantilever blade 60, the principle of generating the vibration frequency, belongs to the prior art (Prior Art), and is not described in detail; the present invention uses the small amplitude flying vibration characteristic of the piezoelectric cantilever blade 60 to be skillfully disposed in the interlayer cavity. The chamber 50 has a small pitch (d) space. In this embodiment, the AC voltage is applied to the piezoelectric cantilever blade 60 through the power line 63, but is not limited thereto. For example, the piezoelectric cantilever blade 60 can be coupled to a circuit board (not shown). It can also be implemented.

Thereby, as shown in FIG. 8 and FIG. 9, when the AC voltage is loaded and driven to drive the piezoelectric cantilever blade 60, the piezoelectric cantilever blade 60 is caused to vibrate with a small amplitude and can be small in the sandwich chamber 50. In the space (d), the gas in the sandwich chamber 50 is compressed and driven to form a gas flow that drives the surface of the heat source 13 to accelerate its heat conduction.

According to the foregoing features, the present invention can be configured to have a predetermined heat dissipation configuration according to the heat dissipation requirement of the heat source 13. The following is a description of a possible embodiment of the heat dissipation configuration, but is not limited thereto.

As shown in FIG. 3A and FIG. 3B, in the first embodiment of the present invention, the frame 30 is disposed on the rear side of the frame 20. In the embodiment, the frame 30 is a U-shaped first frame. 30a, the micro piezoelectric fan heat dissipation module 70 is formed into a single-port heat dissipation configuration 70A of the front lateral opening 31a.

As shown in FIG. 4A and FIG. 4B, the second feasible embodiment of the present invention is the same as the structure of the foregoing embodiment, and the difference is only that the frame 30 is disposed on the left and right sides of the frame 20. On the side, in the embodiment, the frame 30 is a second type frame 30b of a left and right opposite symmetrical U-shaped body, so that the micro piezoelectric fan heat dissipation module 70 forms a front and rear lateral opening. 31b double port heat dissipation configuration 70B.

As shown in FIGS. 5A and 5B, the third possible embodiment of the present invention is the same as the structure of the foregoing embodiment, and the difference is only that the frame 30 is disposed behind the frame 20 and a part thereof. On the left and right sides of the embodiment, in the embodiment, the frame 30 is formed by a rear side edge and a third type frame 30c on the left and right sides, so that the micro piezoelectric fan heat dissipation module 70 is formed. A three-port heat dissipation configuration 70C of three lateral openings 31c.

As shown in FIGS. 6A and 6B, the fourth possible embodiment of the present invention is the same as the structure of the foregoing embodiment, and the difference is only that the frame 30 is disposed at the four end corners of the frame 20. In the embodiment, the frame 30 is provided with a four-frame fourth frame 30d, so that the micro-piezo fan cooling module 70 forms a four-port heat dissipation configuration 70D with four lateral openings 31d.

As shown in FIGS. 7A and 7B, the fifth possible embodiment of the present invention is the same as the structure of the foregoing embodiment, and the difference is only that the frame 30 is disposed around the periphery of the frame 20. In this embodiment, the frame 30 is provided with a closed fifth frame 30e, and an opening 41 is disposed on the top surface of the baffle 40, so that the micro piezoelectric fan heat dissipation module 70 forms a four. The peripherally closed upward heat dissipation configuration 70E.

Referring to FIG. 8 and FIG. 9, the fourth possible embodiment will be further described to further illustrate the structural features of the present invention. The experimental result of the micro piezoelectric fan heat dissipation module 70: when comparing the configuration of the number of different heat dissipation ports and the direction of guiding the air flow, the heat dissipation capability of the laterally guided heat flow is better, and the four sides of the fourth embodiment are The four-port heat dissipation configuration 70D of the opening 31d is optimal. The micro piezoelectric fan cooling module 70 of the present invention is tested. When the module has a thickness of 4 mm and is driven by a power of 70.4 mW (14.3 V/4.92 mA), the cantilever amplitude is 2.0 mm, and the heat dissipation capability is about 81 W. When the module thickness is reduced to 2mm, the heat dissipation capacity is about 48W. In the experimental process of the present invention, in order to facilitate the measurement of the heat dissipation capability, the test is performed with a 60 mm x 60 mm x 2 mm heat dissipation module, and the actual application can scale the interlayer size and thickness to achieve different heat dissipation space and heat dissipation capability.

Therefore, compared with the conventional motor axial flow heat dissipation, the micro piezoelectric fan cooling module 70 consumes only 4.5% of the power consumption, and the heat dissipation space is reduced to 13%, with low energy consumption and small heat dissipation space. The characteristics of the two-piece piezoelectric leaf fan with the same heat dissipation capability, the smaller the accommodating space and the guiding of the hot air scatter, can be used as a component for the heat dissipation of the portable 3C product.

Based on the above configuration, the micro piezoelectric fan heat dissipation module 70 of the present invention has the following effects and needs to be clarified: 1. Guide heat dissipation: the micro piezoelectric fan heat dissipation module 70 of the present invention can adjust the interlayer cavity The configuration of the chamber 50 precisely controls the direction of the airflow and the direction of heat dissipation without creating a disordered airflow in the assembly. Furthermore, the air flow and the heat dissipation are guided by the deflector 40 and the heat dissipation port. Compared with the conventional air cooling mode, the heat dissipation device of the present invention is directional, so it is applied to the heat dissipation of the 3C product, and the heat energy can be guided by the ventilation hole to disperse. It will not escape to the accumulation in the body space, and the same applies to the ventilation of cracks and corners. 2. Miniaturization: The micro piezoelectric fan heat dissipation module 70 of the present invention changes the heat dissipation characteristics of the vertical fan of the conventional piezoelectric fan fan system, and the piezoelectric leaf fan vibrates and the inner wall of the interlayer chamber 50 forms a surface of the heat source. The airflow has a heat dissipation function that accelerates heat conduction, which greatly reduces the volume of the heat dissipation module. 3. Small accommodation space: The micro piezoelectric fan heat dissipation module 70 of the invention is closely connected with the heat source during heat dissipation, and has higher thermal conductivity than the axial flow fan and the two-piece piezoelectric fan, and greatly reduces the required accommodation. Space, suitable for high-performance, small electronic instruments and product heat dissipation, and can be cooled for specific high-heat components (such as CPU, battery, LED lighting) to extend component life and reduce losses. 4. Modularization: The miniature piezoelectric fan heat dissipation module 70 of the present invention is convenient to assemble and apply (bonding the thermal paste to the surface of the heat source); and can be combined with the space of the body, component distribution and heat dissipation capability, and the heat dissipation mode is scaled. Group size, height, or change the vent design. 5. Covering structure: The micro piezoelectric fan heat dissipating module 70 of the present invention improves the conventional fan component to be exposed to the body, and is covered by the sandwich structure, and has no dust accumulation during operation, and does not form a dispersion in the body. Indiscriminate airflow, and noise reduction by the sandwich material, shock absorption and shielding interference; further, the bearingless rotor is not easy to damage and has high stability, and is suitable for heat dissipation of circuit components used in today's 3C products.

By means of the above-mentioned technical means, the micro piezoelectric fan heat dissipation module 70 of the present invention applies the thin and light geometric characteristics of the piezoelectric fan, and combines the sandwich chamber 50 formed by the heat dissipation metal plate 10 and the baffle 40 to form a surface for driving the heat source. The air flow has a heat dissipation function for accelerating heat conduction, and can shield the vibration and the turbulence of the piezoelectric fan during heat dissipation. Furthermore, the present invention utilizes the heat dissipation port configuration in the sandwich chamber 50 to meet the demand, thereby achieving the best. Cooling benefits.

In summary, the technical means disclosed in the present invention have the invention patents such as "novelty", "progressiveness" and "available for industrial use", and pray for the patent to encourage the invention. German sense.

The drawings and the descriptions of the present invention are merely preferred embodiments of the present invention, and those skilled in the art, which are subject to the spirit of the present invention, should be included in the scope of the patent application.

10‧‧‧heated metal sheet
11‧‧‧ first surface
12‧‧‧ second surface
13‧‧‧heat source
20‧‧‧Frame
21‧‧‧Installation
30‧‧‧Border
30a‧‧‧ first type border
30b‧‧‧Second type border
30c‧‧‧3rd type border
30d‧‧‧Fourth type border
30e‧‧‧5th type border
31a, 31b, 31c, 31d, 31e, 41‧‧
40‧‧‧Baffle
50‧‧‧Mezzanine chamber
60‧‧‧ Piezoelectric cantilever blades
61‧‧‧Flexible film
62‧‧‧Thin piezoelectric element
63‧‧‧Power cord
70‧‧‧Micro Piezo Fan Cooling Module
70A‧‧‧Single-port heat dissipation configuration
70B‧‧‧Double-port heat dissipation configuration
70C‧‧‧Three heat dissipation configurations
70D‧‧‧ four-port heat dissipation configuration
70E‧‧‧Upward heat dissipation configuration

Figure 1 is a schematic view of a conventional axial flow fan. Fig. 2 is a schematic view showing a conventional jet type two-piece piezoelectric leaf fan. Figure 3A is an exploded perspective view of a first possible embodiment of the present invention. Figure 3B is a combined perspective view of a first possible embodiment of the present invention. Figure 4A is an exploded perspective view of a second possible embodiment of the present invention. Figure 4B is a combined perspective view of a second possible embodiment of the present invention. Figure 5A is an exploded perspective view of a third possible embodiment of the present invention. Figure 5B is a combined perspective view of a third possible embodiment of the present invention. Figure 6A is an exploded perspective view of a fourth possible embodiment of the present invention. Figure 6B is a combined perspective view of a fourth possible embodiment of the present invention. Figure 7A is an exploded perspective view of a fifth possible embodiment of the present invention. Figure 7B is a combined perspective view of a fifth possible embodiment of the present invention. Figure 8 is a cross-sectional view showing a fourth possible embodiment of the present invention. Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8.

10‧‧‧heated metal sheet

11‧‧‧ first surface

20‧‧‧Frame

30‧‧‧Border

30d‧‧‧Fourth type border

31d‧‧‧ openings

50‧‧‧Mezzanine chamber

60‧‧‧ Piezoelectric cantilever blades

61‧‧‧Flexible film

62‧‧‧Thin piezoelectric element

70‧‧‧Micro Piezo Fan Cooling Module

70D‧‧‧ four-port heat dissipation configuration

Claims (8)

A miniature piezoelectric fan heat dissipation module includes a heat dissipation metal plate having a first surface and an opposite side as a second surface contacting a predetermined heat source; a frame disposed on the first surface of the heat dissipation metal plate And the height of the frame is lower than 4 mm; at least one frame is disposed on one side of the frame to form a heat dissipation configuration of a predetermined opening; a deflector is disposed above the frame And forming a sandwich chamber having a pitch of less than 4 mm with the heat dissipation metal plate; and a piezoelectric cantilever blade having a rectangular area smaller than the frame, comprising a flexible piece and a flexible layer a thin piezoelectric element having a sheet surface, one end of which is fixed on the frame, the corresponding end extends forward to form a free end, and the free end of the piezoelectric cantilever blade is suspended between the interlayer chamber; Thereby, when the voltage is sent to the piezoelectric cantilever beam, the piezoelectric cantilever blade is caused to vibrate with a small amplitude, and the interlayer cavity can be compressed and driven in a small space of the interlayer chamber. The indoor gas forms an air flow in a direction parallel to the surface of the heat source, thereby taking away heat energy of the heat radiating metal plate and accelerating heat conduction thereof. The micro piezoelectric fan heat dissipation module of claim 1, wherein the frame is disposed on a rear side of the frame, so that the micro piezoelectric fan heat dissipation module forms a single side heat dissipation of the front side opening. structure. The micro piezoelectric fan heat dissipation module according to claim 1, wherein the frame is disposed on the left and right sides of the frame, so that the micro piezoelectric fan heat dissipation module forms a front, Rear double-opening heat dissipation configuration. The micro piezoelectric fan cooling module according to claim 1, wherein the frame is disposed on the left side and the right side of the side and a part of the frame, so that the micro piezoelectric fan cooling module Forming a three-port heat dissipation configuration with three lateral openings. The micro piezoelectric fan heat dissipation module according to claim 1, wherein the frame is disposed on the four end corners of the frame, so that the micro piezoelectric fan heat dissipation module forms a four lateral opening. The four-port heat dissipation configuration. The micro piezoelectric fan heat dissipation module according to claim 1, wherein the frame is disposed around the periphery of the frame, and an opening is provided on the top surface of the baffle to make the micro piezoelectric The fan heat dissipation module forms a four-perimeter closed upward heat dissipation configuration. The micro piezoelectric fan heat dissipation module according to any one of claims 1 to 6, wherein the frame comprises: being fixed to the frame in a combined manner, or directly integrally formed on the frame. The micro piezoelectric fan heat dissipation module according to any one of claims 1 to 6, wherein the baffle is disposed on a frame above the frame.