TWI398215B - Casing and manufacturing method thereof - Google Patents

Description

Case and manufacturing method thereof

The present invention relates to a casing for an electronic device, and more particularly to a casing that contributes to heat dissipation and a method of fabricating the same.

At present, consumer electronic products such as digital cameras, mobile phones, notebook computers, etc., have increasingly complex functions, the number of power crystals is constantly increasing, and the body requirements are light and thin, and the internal space is very small, so that heat accumulation The situation is particularly serious. In order to make the power crystal operate at normal operating temperature and maintain the normal service life of the product, most of the electronic devices are provided with corresponding heat dissipation modules or heat dissipation structures. In addition, in order to reduce the noise of the product and save the power consumption of the portable device, the use of the exhaust fan is also limited, which makes the problem of thermal management more severe.

At present, most electronic products use plastic and metal alloys (such as aluminum-magnesium alloy) as the casing. Taking the electronic products of the plastic case as an example, copper foil, aluminum foil or graphite sheets are often placed in the plastic casing of the electronic product, and a large heat dissipation area such as copper foil, aluminum foil or graphite sheet is used for heat dissipation to reduce the power crystal. Operating temperature.

Among them, the plastic casing has the advantages of easy molding, small specific gravity, mature surface treatment technology and various changes. However, the plastic case itself lacks the shielding effect of electromagnetic interference (EMI) and radio frequency interference (RFI), and the thermal conductivity of the plastic material is low, and the heat dissipation performance is poor, so that the temperature of the heating element is too high and shortened. Original life. If additional materials such as copper foil, aluminum foil and graphite sheet are added, the production time will be lengthened and the labor will be increased, which increases the cost and volume of the product.

On the other hand, if an electronic product using a metal case (such as an aluminum-magnesium alloy) is used, the aluminum-magnesium case can be directly used to introduce heat into the outside to dissipate heat. The aluminum-magnesium alloy has a small specific gravity, good electromagnetic wave and radio frequency shielding effect, high recycling property is environmentally friendly, and has high heat transfer coefficient and good heat dissipation performance.

However, due to the good thermal conductivity of the metal casing, heat is concentrated on the surface of the local casing adjacent to the heating element, causing the temperature of the casing to rise locally. If the user operates the electronic device and comes into contact with it, it may feel hot and uncomfortable. For example, if the notebook computer has a power supply module, display chip or central under the palm rest. High-power heating elements such as processors may cause an operator's uncomfortable feeling.

In order to solve the problem of heat concentration of a part of the casing surface during heat dissipation of the conventional electronic device, the present invention provides a concept of a casing and a manufacturing method of the casing, which utilizes a thermal barrier layer corresponding to the position of the heating element to prevent direct conduction of heat energy to the machine. A specific area on the surface of the shell body to solve the above heat concentration problem.

One aspect of the present invention is to provide a housing for use in an electronic device wherein the electronic device includes at least one heat generating component therein.

According to a specific embodiment, the housing includes a housing body, a thermal barrier layer, and a thermal diffusion layer. Among them, the shell system is made of metal. The thermal barrier layer is disposed on the inner wall of the casing body and has a position corresponding to the heating element. The thermal diffusion layer is disposed on the inner wall of the thermal barrier layer and the casing body, and the thermal diffusion layer comprises a plurality of flat holes, the holes of the holes being parallel to the direction in which one of the casing bodies extends.

Another aspect of the present invention is to provide a casing manufacturing method for manufacturing a casing of an electronic device, wherein the electronic device includes at least one heating element therein.

According to a specific embodiment, the housing manufacturing method comprises the steps of first providing a housing body. Next, a thermal barrier layer is formed on the inner wall of the casing body, and the position of the thermal barrier layer corresponds to the heating element. Finally, a thermal diffusion layer is formed on the inner wall of the thermal barrier layer and the casing body, wherein the thermal diffusion layer comprises a plurality of flat holes, the holes of which are parallel to the direction in which one of the casing bodies extends.

The advantages and spirit of the present invention will be further understood from the following detailed description of the invention.

Please refer to FIG. 1. FIG. 1 is a schematic diagram of an electronic device 2 and a casing 1 thereof according to an embodiment of the present invention. As shown in FIG. 1 , the casing 1 is suitable for being disposed on the surface of the electronic device 2 , and the electronic device 2 can be a notebook computer, a personal computer system, a mobile phone or various other electronic devices. The electronic components, when the various electronic components are energized, generate different degrees of thermal energy, and the electronic components in these operations are the heating elements 20. For example, the main heating element 20 commonly found in the electronic device 2 can be a wireless communication module, a display module, a backlight, a storage medium, a battery, a processing chip, or a graphics chip. In today's high-performance and high-frequency processing electronic devices, the thermal energy dissipated by these heating elements 20 will cause the internal temperature of the electronic device 2 to rise, and if the heat is not properly dissipated, the stability of the electronic device 2 will be lowered, and even the electronic device will be caused. 2 permanent damage. In this embodiment, the casing 1 contributes to heat dissipation of the heat generating component 20.

2 is a cross-sectional view of the casing 1 in accordance with an embodiment of the present invention.

As shown in FIG. 2, the casing 1 includes a casing body 10, a thermal barrier layer 12, and a thermal diffusion layer 14. In this embodiment, the casing 1 further includes an electrically insulating thermally conductive layer 16. In the casing 1 of the embodiment, the casing body 10 is disposed on the outer surface of the electronic device 2 and exposed to the external space. For example, the material of the casing body 10 may be magnesium alloy, aluminum alloy, or steel. Or iron, etc., but the invention is not limited thereto. The casing body 10 itself is a good conductor of heat for heat exchange with the outside world for heat dissipation.

As shown in FIG. 2, an electrically insulating and thermally conductive layer 16 is disposed on the inner wall of the casing body 10. In practical applications, the electrically insulating and thermally conductive layer 16 can be spray-sprayed and sprayed in the form of electric-insulating and high-thermal-conductivity ceramics, and the thickness is between 10 and 50 μm. And an electrically insulating thermally conductive ceramic layer having a porosity of less than 10%. In practical applications, the highly thermally conductive ceramic material of the electrically insulating and thermally conductive layer 16 is made of free alumina (Al ₂ O ₃ ), tantalum nitride (Si ₃ N ₄ ), boron nitride (BN) and aluminum nitride. The group consisting of (AlN) may also be other materials having high thermal conductivity but electrically insulating, wherein aluminum nitride is preferred, and the ceramic powder may have a particle size of 10 to 500 nm. In this embodiment, the electrically insulating thermally conductive layer 16 can avoid electrochemical corrosion caused by standard potential differences between the heterogeneous materials (ie, between the casing body 10 and the thermal barrier layer 12 and the thermal diffusion layer 14) (eg, Gavigny). Galvanic corrosion) increases the internal corrosion resistance of the casing body 10. It should be noted that the present invention does not limit the necessity of adding an electrically insulating and thermally conductive layer 16 between the casing body 10 and the thermal diffusion layer 14. If the electrochemical corrosion effect is not obvious, the electrically insulating and thermally conductive layer 16 may be omitted. This reduces manufacturing costs and streamlines the manufacturing process.

The thermal barrier layer 12 of the present invention can be directly disposed on the inner wall of the casing body 10. In this embodiment, since the casing 1 further has an electrically insulating and thermally conductive layer 16, the thermal barrier layer 12 is formed on the inner wall of the thermal diffusion layer 14 and the casing body 10 as shown in FIG. Between the 16th, that is, the electrically insulating and thermally conductive layer is disposed between the thermal barrier layer 12 and the inner wall of the casing body 10 and between the thermal diffusion layer 14 and the inner wall of the casing body 10, and the position of the thermal barrier layer 12 corresponds to the electronic device. 2 where the heating element is located. That is, the casing 1 of the present invention can be sprayed, coated or otherwise provided with a layer of material having a low thermal conductivity near the heat generating component 20 to form a thickness of about 10 to 500 μm and a porosity of 5 to 10%. The material of the thermal barrier layer 12, which has a low thermal conductivity, may be selected from, but not limited to, a polymer, a glass fiber, a low thermal conductive ceramic material, or various oxides.

In another embodiment, the thermal diffusion layer 14 of the present invention can be disposed directly on the inner walls of the thermal barrier layer 12 and the casing body 10. In this embodiment, since the casing 1 further has an electrically insulating and thermally conductive layer 16, as shown in FIG. 2, one side of the thermal diffusion layer 14 is connected to the thermal barrier layer 12 and the electrically insulating thermally conductive layer 16, and the other side is facing the electron. The heating element 20 of the device 2. As shown in FIG. 2, the thermal diffusion layer 14 is in indirect contact with the heat generating component 20 through the thermally conductive interface material 18. The heat conductive interface material 18 herein may be a thermal conductive paste or a thermal conductive sheet, etc., and the invention is not limited thereto. In another embodiment, the thermal diffusion layer 14 of the present invention may also be in direct contact with the heat generating component 20 without passing through the thermally conductive interface material 18.

In practical applications, the thermal diffusion layer 14 can be formed by melting a material having a high thermal conductivity (for example, copper, silver, aluminum, high thermal conductivity ceramic material, carbon fiber, graphite, diamond-like, etc.) by a spray coating process. The molten particles having a size of about 1 to 250 μm are impacted on the substrate at a high speed and adhered to the surface of the substrate to form a thermal diffusion layer 14 having a thickness of about 0.1 to 1.0 mm and a porosity of about 5 to 40%.

In particular, in the manufacturing process of the thermal diffusion layer 14, when a single molten sprayed particle hits the surface of the substrate at a high speed, a flat sheet is formed, and each of the sheets is solidified and solidified and stacked. Forming a continuous film layer, there are still small voids between the accumulated stacked sheets and the sheet, so that the heat diffusion layer 14 has a plurality of flat holes 140 whose holes are parallel to the casing One of the bodies 10 extends in the direction (as shown in Figure 2).

Due to the impact of the molten particles, the holes 140 in the heat diffusion layer 14 also form a flat shape parallel to the sheet, since the flat holes 140 block the heat energy transmission path, so that the vertical heat diffusion layer 14 extends in the heat diffusion layer 14. The vertical heat transfer coefficient of the direction is decreased, so that the horizontal heat transfer rate of the heat diffusion layer 14 in the extending direction is greater than the vertical heat transfer rate perpendicular to the extending direction. This state causes the porous coating layer (the thermal diffusion layer 14) to have characteristics of different heat transfer coefficients in all directions, and can function as a thermal lateral diffusion layer.

Please refer to FIG. 3 together. FIG. 3 is a schematic diagram showing the thermal energy flow path of the thermal diffusion layer 14 in the casing 1. In the casing 1 of this embodiment, the thermal diffusion rate of the thermal diffusion layer 14 in the horizontal direction is greater than the thermal conduction rate in the vertical direction, and the arrangement of the thermal barrier layer 12 with a low thermal conductivity blocks the heating element 20 to the casing. A straight path of the body 10. When the heat generating component 20 in the electronic device 2 generates thermal energy, the thermal energy can be diffused in the horizontal extending direction of the thermal diffusion layer 14 and finally transmitted to the casing body 10 on average, thereby reducing the surface of the casing of the electronic device 2 The phenomenon of high temperature.

Referring to FIG. 4, FIG. 4 is a flow chart of a method for fabricating a casing according to an embodiment of the present invention. The casing manufacturing method is applied to a casing for manufacturing an electronic device, wherein the electronic device includes at least one heating element therein.

As shown in FIG. 4, the casing manufacturing method first performs step S100 to provide a casing body. Next, step S102 is performed to form an electrically insulating thermally conductive layer on the inner wall of the casing body. Next, step S104 is performed to form a thermal barrier layer on the electrically insulating and thermally conductive layer of the inner wall of the casing body, and the position of the thermal barrier layer corresponds to the heating element of the electronic device. Finally, step S106 is performed to form a thermal diffusion layer on the electrically insulating and thermally conductive layer of the thermal barrier layer and the inner wall of the casing body, wherein the thermal diffusion layer comprises a plurality of flat holes, the holes of which are parallel to the machine One of the shell bodies extends in the direction.

The manufacturing process of forming the electrically insulating and thermally conductive layer in step S102, forming the thermal barrier layer in step S104, and forming the thermal diffusion layer in step S106 can be completed by the spray coating process.

Wherein, the thermal diffusion layer can be used to directly contact the heating element of the electronic device. Or in another embodiment, a manufacturing step may be further added to provide a thermal interface material between the thermal diffusion layer and the heat generating component, and the thermal diffusion layer is indirectly contacted with the heat generating component through the thermal interface material.

In the above embodiment, step S102 forms an electrically insulating and thermally conductive layer between the casing body and the inner two layers (the thermal barrier layer and the thermal diffusion layer). In another embodiment, the electrically insulating and thermally conductive layer formed in step S102 and the insulating layer may be omitted, so that the thermal barrier layer in step S104 is directly formed on the casing body, and the heat diffusion in step S106 is similarly performed. The layer is formed on the casing body and the thermal barrier layer.

It should be noted that the thermal diffusion layer formed by the spray coating process comprises a plurality of flat holes whose holes are parallel to the direction in which one of the casing bodies extends, so that one of the thermal diffusion layers is horizontally thermally conductive. The rate is greater than the vertical thermal conductivity rate of one of the vertical extension directions.

For the housing of the above-mentioned casing manufacturing method, the material and the manufacturing method can be referred to the detailed description of the casing of the above embodiment, and therefore no further details are provided herein.

In order to improve the temperature unevenness of the surface of the casing of the conventional electronic device, the method for manufacturing the casing and the casing provided by the invention has a heat diffusion layer with different heat conduction coefficients in all directions, so that the temperature of the casing is uniformized and avoided. The local temperature of the surface of the casing is too high. The pores of the thermal diffusion layer are flat, and the direction of the holes is parallel to the direction of the substrate of the casing, so that the thermal conductivity of the thermal diffusion layer is different in each direction, and the thermal conductivity in the vertical direction is smaller than the other two directions, so that most of the heat is diffused. Spread out, and less directly penetrate the casing to avoid high local temperature on the surface of the casing.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

1. . . cabinet

10. . . Chassis body

12. . . Thermal barrier layer

14. . . Thermal diffusion layer

16. . . Electrically insulating layer

18. . . Thermal interface material

140. . . Hole

2. . . Electronic device

20. . . Heating element

S100~S106. . . Process step

1 is a schematic diagram of an electronic device and a casing thereof according to an embodiment of the present invention.

2 is a cross-sectional view of a casing in accordance with an embodiment of the present invention.

3 is a schematic view showing a thermal energy flow path of a thermal diffusion layer of a casing according to an embodiment of the present invention.

4 is a flow chart of a method of fabricating a casing in accordance with an embodiment of the present invention.

1. . . cabinet

10. . . Chassis body

12. . . Thermal barrier layer

14. . . Thermal diffusion layer

16. . . Electrically insulating layer

18. . . Thermal interface material

140. . . Hole

2. . . Electronic device

20. . . Heating element

Claims (14)

A casing is applied to an electronic device, wherein the electronic device comprises at least one heating element, the casing comprises: a casing body, which is made of metal material; and a thermal barrier layer disposed on the inner wall of the casing body And a position corresponding to the heat generating component; and a heat diffusion layer disposed on the inner wall of the heat barrier layer and the casing body, and the heat diffusion layer comprises a plurality of flat holes The holes of the holes are parallel to a direction in which one of the casing bodies extends; wherein a thermal conductivity of the thermal diffusion layer along one of the extending directions is greater than a vertical thermal conductivity of the one of the extending directions. The casing of claim 1, wherein the casing further comprises an electrically insulating thermally conductive layer disposed between the thermal barrier layer and the inner wall of the casing body and the thermal diffusion layer and the casing Between the inner walls of the body. The casing of claim 2, wherein the electrically insulating thermally conductive layer is made of a highly thermally conductive ceramic material, and the material is selected from the group consisting of free alumina, tantalum nitride, boron nitride, and aluminum nitride. Group of. The casing of claim 2, wherein the electrically insulating thermally conductive layer is formed via a spray coating process. The casing of claim 1, wherein the thermal barrier layer and the thermal diffusion layer are formed by a spray coating process. The casing of claim 1, wherein the thermal diffusion layer contacts the heating element through a thermally conductive interface material. The casing of claim 6, wherein the heat conducting interface material is Thermal paste or a thermal pad. A casing manufacturing method for manufacturing a casing of an electronic device, wherein the electronic device comprises at least one heating element, the casing manufacturing method comprising the steps of: providing a casing body; forming a thermal barrier layer thereon An inner wall of the casing body, wherein the thermal barrier layer is located at a position corresponding to the heat generating component; and a heat diffusion layer is formed on the inner wall of the heat barrier layer and the casing body, wherein the heat diffusion layer comprises a plurality of The flat holes have a hole direction parallel to a direction in which one of the casing bodies extends; wherein a thermal conductivity of the thermal diffusion layer along one of the extending directions is greater than a vertical heat conduction rate perpendicular to the extending direction. The method for manufacturing a casing according to claim 8, wherein before the step of forming the thermal barrier layer on the inner wall of the casing body, the casing manufacturing method further comprises the steps of: forming an electric An insulating thermally conductive layer is disposed between the thermal barrier layer and the inner wall of the housing body and between the thermal diffusion layer and the inner wall of the housing body. The method for manufacturing a casing according to claim 9, wherein the material of the electrically insulating and thermally conductive layer is a high thermal conductivity ceramic material, and the material thereof is selected from the group consisting of free alumina, tantalum nitride, boron nitride, and aluminum nitride. The group formed. The method for fabricating a casing according to claim 9, wherein the step of forming the electrically insulating thermally conductive layer is completed by a spray coating process. The method for fabricating a casing according to claim 8, wherein the step of forming the thermal barrier layer and the step of forming the thermal diffusion layer are performed by a spray coating method. The process is completed. The method for fabricating a casing according to claim 8, wherein after the forming the thermal diffusion layer, the method for manufacturing the casing further comprises the steps of: providing a thermal interface material between the thermal diffusion layer and the heating element The heat diffusion layer is in contact with the heat generating component through the heat conductive interface material. The method for manufacturing a casing according to claim 13, wherein the heat conducting interface material is a thermal conductive paste or a thermal conductive sheet.