Chip-oriented focusing type acoustic streaming heat dissipation device

Abstract

The invention discloses a focusing type acoustic streaming heat dissipation device facing a chip. The device belongs to the crossing field of ultrasonic technology and heat dissipation technology and is composed of a piezoelectric stack, an acoustic lens, a splitter plate, a base, a supporting rod, a copper electrode and the like. According to the device, geometric parameter configuration of the splitter plate, the piezoelectric stack and the acoustic lens is optimized, and a double-piezoelectric-plate stacked structure is adopted to enhance the ultrasonic resonance effect; high-frequency alternating voltage is applied to the copper electrodes at the two ends of the piezoelectric stack, high-frequency sound waves are excited through the inverse piezoelectric effect, and after the sound waves are focused through the sound lens, a gradient sound pressure field is formed in a cavity formed by the splitter plate and the piezoelectric stack; air molecules are driven to move directionally based on the acoustic streaming effect, so that air flow at an air inlet is accelerated by sound pressure to form high-flow-rate focusing jet flow at an air outlet, and targeted forced convection heat dissipation of a chip heat source is realized. According to the device, the ultrasonic technology and the heat dissipation technology are combined, the whole device is simple in structure, free of moving parts and low in noise, and various heat dissipation requirements can be met in an array mode.

Description

Technical Field

[0001] The present invention belongs to the cross - field of ultrasonic technology and heat dissipation technology, and relates to a focusing acoustic streaming heat dissipation device for chips. Background Art

[0002] With the rapid development of electronic technology, the integration and power consumption of chips are constantly increasing, and their heat generation is also increasing. Traditional heat dissipation methods, such as air cooling and liquid cooling, have disadvantages such as low heat dissipation efficiency, high noise, and large volume. In recent years, heat dissipation technology based on the acoustic streaming effect has gradually attracted attention. The acoustic streaming effect refers to the phenomenon that when sound waves propagate in a fluid, due to the existence of a sound pressure gradient, the fluid will be driven to flow. Using the acoustic streaming effect for heat dissipation has advantages such as no moving parts, low noise, and high heat dissipation efficiency.

[0003] Acoustic superlens, as an element that can change the propagation path of sound waves, has been widely used in fields such as ultrasonic imaging and ultrasonic therapy. In recent years, some researchers have begun to explore the combination of acoustic lenses and ultrasonic technology for more efficient heat dissipation. This heat dissipation method utilizes the vibration effect of ultrasonic waves in a medium to quickly take away heat from the heat source and dissipate it to the surrounding environment through heat convection or heat radiation.

[0004] However, applying acoustic lenses and ultrasonic technology to chip heat dissipation still faces some technical challenges. For example, how to ensure that ultrasonic waves can be accurately focused on the chip heat source to achieve fixed - point heat dissipation.

[0005] Therefore, there is an urgent need for a focusing acoustic streaming heat dissipation device for chips. Summary of the Invention

[0006] Object of the Invention: The object of the present invention is to propose a focusing acoustic streaming heat dissipation device for chips that can ensure that ultrasonic waves can be accurately focused on the chip heat source to achieve fixed - point heat dissipation.

[0007] Technical Solution: A focusing acoustic streaming heat dissipation device for chips according to the present invention includes a base. A copper electrode is adhesively bonded to the upper end of the base with glue. A piezoelectric sheet is adhesively bonded to the upper end of the copper electrode with glue. An acoustic lens is also adhesively bonded to the upper end of the piezoelectric sheet with glue.

[0008] Furthermore, a flow - dividing plate is arranged around the upper end of the copper electrode, the acoustic lens and the piezoelectric sheet;

[0009] An air outlet is opened at the center position of the top of the flow - dividing plate, and an air inlet is opened at its side wall.

[0010] Furthermore, three support rods passing through the piezoelectric sheet and the copper electrode are arranged on the base,

[0011] The flow splitter is supported and fixed by three support rods installed on the base, and its internal structure is obtained through multiple simulations.

[0012] Further, the piezoelectric sheet is a circular thin sheet with a diameter of 15 mm - 20 mm, a thickness of 1.5 mm - 2.1 mm, a resonance frequency range of 20 kHz - 200 kHz, and the working frequency f is between 113.93 kHz - 114.83 kHz; and the effective working voltage range is 7.5 v - 10 v.

[0013] Further, the piezoelectric sheet is stacked by two piezoelectric sheets to increase the power of the overall device.

[0014] Further, in the copper electrode, its bonding surface has the same size as the piezoelectric sheet and a thickness of 0.5 mm - 1 mm, and the diameter of the outer semi - circle at its outer end is 0.2 mm - 0.5 mm;

[0015] The positive pole of its power supply is connected to the positive pole of the copper electrode, and the negative pole of the power supply is connected to the negative pole of the copper electrode.

[0016] Further, the acoustic lens is an aluminum lens with a bottom diameter of 15 mm - 20 mm and a radius of curvature of 9 mm - 20 mm;

[0017] The bottom of its non - concave surface is bonded to the top - most piezoelectric sheet with glue.

[0018] Further, both the base and the support rods are made of 304 stainless steel.

[0019] Further, the manufactured focused acoustic streaming heat dissipation device is closely attached to the mobile phone back panel in an array of 5 - 10×3 - 5 by glue.

[0020] Further, the size of the mobile phone back panel is 145 mm×70 mm×1 mm.

[0021] The overall thickness of the focused acoustic streaming heat dissipation device is controlled within 3 - 6 mm,

[0022] The power of each device in the array is 0.2 w - 1 w.

[0023] The beneficial effects of the present invention are as follows: Compared with the prior art, the present invention has the following advantages: (1) By using acoustic focusing technology to generate high-intensity acoustic streaming, a directional fluid disturbance is directly formed in the hot spot area of the chip, breaking through the limitation of the traditional heat dissipation boundary layer and significantly enhancing the local convective heat transfer coefficient; without relying on fans or liquid cooling pipelines, the air or cooling medium is driven to flow through the sound field, reducing the interfacial thermal resistance in the heat transfer path, and is particularly suitable for high-power density chips; (2) Simple structure, small volume, low cost, low energy consumption, high cooling efficiency, and little impact on the environment; (3) Can be adapted to air, inert gas or liquid medium to meet different heat dissipation requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the overall external structure of the present invention;

[0025] Figure 2 is a schematic diagram of the array in Embodiment 1 of the present invention.

[0026] Figure 3 is a schematic diagram of the array in Embodiment 2 of the present invention.

[0027] In the figure: 1 is a flow splitter plate, 101 is an air inlet, and 102 is an air outlet;

[0028] 2 is an acoustic lens, and 3 is a piezoelectric sheet;

[0029] 4 is a copper electrode, 401 is the positive copper electrode, and 402 is the negative copper electrode;

[0030] 5 is a base, 6 is a support rod, 7 is a focused acoustic streaming heat dissipation device, and 8 is a mobile phone back panel. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following further elaborates on the specific technical solutions of the present invention with reference to specific examples.

[0032] As shown in the figure, a focused acoustic streaming heat dissipation device for a chip according to the present invention includes a flow splitter plate 1, an acoustic lens 2, a piezoelectric sheet 3, a copper electrode 4, a base 5, and a support rod 6.

[0033] The copper electrode 4 is adhesively bonded above the base 5 with glue, and the piezoelectric sheet 3 is adhesively bonded above the copper electrode 4 with conductive glue to ensure electrical conductivity after fixation.

[0034] Two piezoelectric sheets 3 are used in a stacked manner to increase the power of the overall device, and the connection method is the same as above.

[0035] The non-concave bottom of the acoustic lens 2 is adhesively bonded to the topmost piezoelectric sheet 3 with glue.

[0036] The flow splitter 1 is supported and fixed by three support rods 6 on the base, and its internal structure is obtained through multiple simulations, enabling the internal sound pressure to reach the maximum and the ejected wind speed to reach the peak value.

[0037] The piezoelectric sheet 3 is a circular thin sheet with a diameter of 15 mm - 20 mm, a thickness of 1.5 mm - 2.1 mm, a resonance frequency range of 20 kHz - 200 kHz, and the operating frequency f is between 113.93 kHz - 114.83 kHz; and the effective operating voltage range is 7.5 v - 10 v;

[0038] In the copper electrode 4, its bonding surface has the same size as the piezoelectric sheet and a thickness of 0.5 mm - 1 mm, and the diameter of the outer semi - circle at its outer end is 0.2 mm - 0.5 mm;

[0039] The positive pole of the power supply is connected to the positive pole 401 of the copper electrode, and the negative pole of the power supply is connected to the negative pole 402 of the copper electrode.

[0040] The acoustic lens 2 is an aluminum lens with a bottom diameter of 15 - 20 mm and a radius of curvature of 9 - 20 mm.

[0041] The materials of the base 5 and the support rods 6 are 304 stainless steel or steel with higher hardness.

[0042] Under the excitation of an alternating electric field, the piezoelectric sheet 3 generates high - frequency mechanical vibrations through the inverse piezoelectric effect, converting electrical energy into ultrasonic waves; when the ultrasonic waves propagate through the acoustic lens, since the sound speed of the lens material is lower than that of the surrounding medium, the sound waves are refracted at the lens curved - surface interface, and according to the geometric acoustics principle, the propagation path is adjusted, and the sound wave front is redistributed and gradually converges to a preset focal area, forming an ultrasonic beam with a high energy density;

[0043] The acoustic lens 2 focuses the high - frequency sound waves generated by the piezoelectric sheet, forming a high - intensity sound field inside the device, thereby generating a sound pressure gradient, promoting the air inside the device to produce a streaming effect of sound, and forming a high - speed air flow;

[0044] The high - speed air flow flows into the device from the air inlet 101 at high speed and then ejects from the air outlet 102 at high speed, blowing towards the chip surface and taking away the heat generated by the chip, thereby realizing the heat dissipation of the chip.

[0045] In Embodiment 1, an acoustic streaming heat dissipation device 7 facing the chip is closely attached to the mobile phone backplane 8 by glue in an array manner of 5 - 10×3 - 5 (5×3 in the figure) for overall heat dissipation of the internal structure of the mobile phone;

[0046] The size of the mobile phone backplane 8 is approximately 145 mm×70 mm×1 mm.

[0047] By changing the sizes and dimensions of components such as the piezoelectric sheet 3 and the acoustic lens 2, and ensuring that the wind speed is large and stable enough, the overall thickness can be controlled within 3 - 6 mm. After changing the overall size and dimensions, the power of each device in the array is about 0.2 w - 1 w.

[0048] This array device can be connected to a mobile phone in a parallel connection mode and powered by the mobile phone battery for operation.

[0049] When the overall device is working, a high-speed air flow is ejected from the air outlet 102. The air flow accelerates heat exchange through forced convection, and the high-speed air flow can carry away the heat on the surface of the heat sink or heat pipe more quickly.

[0050] In Example 2, the device is pasted on the concave surface of the acoustic lens 2 with glue or viscous filler, and a circular array is implemented on the concave surface of the acoustic lens 2. After the array, the air that originally flowed at a high speed due to the acoustic streaming effect is further accelerated, making the wind speed at the air outlet 102 greater, more concentrated, and more efficient in targeted heat dissipation of the chip.

[0051] The device is arrayed on the bottom section and each level of the circumference. The specific number of arrays can be determined according to the size of the device. (In the figure, there is one device on the bottom surface. At the smaller circumference, the devices are arrayed at an interval of 30°, with a total of 12. At the larger circumference, the devices are arrayed at an interval of 15°, with a total of 24).

[0052] These array devices are connected in series and then in parallel with the power supply connected to the large device to ensure that the overall internal structure power is consistent and the sound pressure at the symmetric parts is kept the same.

Claims

1. A chip-oriented focused acoustic streaming heat dissipation device, comprising a base, characterized in that, A copper electrode is adhesively bonded to the upper end of the base, a piezoelectric sheet is adhesively bonded to the upper end of the copper electrode, and an acoustic lens is also adhesively bonded to the upper end of the piezoelectric sheet.

2. The focused acoustic streaming heat dissipation device for a chip according to claim 1, characterized in that, A current shunt plate is installed around the upper end of the copper electrode, the acoustic lens and the piezoelectric sheet. An air outlet is provided at the center of the top of the current shunt plate, and an air inlet is provided at its side wall.

3. The focused acoustic streaming heat dissipation device for a chip according to claim 2, characterized in that, Three support rods passing through the piezoelectric sheet and the copper electrode are installed on the base. The current shunt plate is supported and fixed by the three support rods installed on the base, and its internal structure is obtained by multiple simulations.

4. The focused acoustic streaming heat dissipation device for a chip according to claim 3, characterized in that The piezoelectric sheet is a circular thin sheet with a diameter of 15 mm - 20 mm, a thickness of 1.5 mm - 2.1 mm, a resonance frequency range of 20 kHz - 200 kHz, and the working frequency f is between 113.93 kHz - 114.83 kHz; and the effective working voltage range is 7.5 V - 10 V.

5. The focusing acoustic streaming heat dissipation device for a chip according to claim 3, characterized in that, The piezoelectric sheet is stacked by two piezoelectric sheets to increase the power of the overall device.

6. The focused acoustic streaming heat dissipation device for a chip according to claim 3, wherein In the copper electrode, the bonding surface has the same size as the piezoelectric sheet and a thickness of 0.5 mm - 1 mm, and the diameter of the outer semi-circle is 0.2 mm - 0.5 mm. The positive pole of the power supply is connected to the positive pole of the copper electrode, and the negative pole of the power supply is connected to the negative pole of the copper electrode.

7. The focusing acoustic streaming heat dissipation device for a chip according to claim 1, wherein The acoustic lens is an aluminum lens with a bottom diameter of 15 mm - 20 mm and a radius of curvature of 9 mm - 20 mm. The bottom of its non-concave surface is adhesively bonded to the topmost piezoelectric sheet with glue.

8. The focusing acoustic streaming heat dissipation device for a chip according to claim 3, characterized in that The materials of the base and the support rods are both made of 304 stainless steel.

9. The focusing acoustic streaming heat dissipation device for a chip according to claim 1, characterized in that, The manufactured focused acoustic streaming heat dissipation device is closely attached to the mobile phone backplane by glue in an array of 5 - 10×3 - 5.

10. A chip-oriented focused acoustic streaming heat dissipation device according to claim 9, characterized in that, The size of the mobile phone backplane is 145 mm×70 mm×1 mm. The overall thickness of the focused acoustic streaming heat dissipation device is controlled within 3 - 6 mm. The power of each device in the array is 0.2 W - 1 W.

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