TWI556375B - Comeposite heat spreader and thermoelectric device thereof - Google Patents

Description

Composite heat sink and thermoelectric device

The invention relates to a heat dissipating component, in particular to a composite heat sink having both heat conduction and heat radiation functions and a thermoelectric device thereof.

In recent years, electronic devices such as ultra-thin notebooks (Ultrabooks), tablets, and smart phones have become more and more demanding, resulting in power dissipation and relative heat flow (Heat Flux) of electronic components. It is also getting higher and higher; electronic devices are also facing a light, thin and short design trend, and the design direction of such extreme compression space often causes difficulty in heat dissipation, so the heat dissipation problem has become one of the first problems overcome by the electronics industry.

For example, in the construction of a conventional circuit board, since the number of electronic components and power consumption are low, heat generated by the electronic components can be conducted through the copper foil layer and directly dissipate heat into the ambient air. Nowadays, the number of electronic components disposed on the circuit board is large and the power is high. The problem is that as the current increases and the power consumption increases, the local heat generated excessively rises, so the electronic component contacts the foot ( The heat removal method has been unable to dissipate most of the heat, so that the electronic components and the circuit board cannot be maintained at the normal operating temperature, resulting in a change in the physical characteristics of the electronic components, thereby failing to achieve the predetermined working efficiency. For the user, it is very likely that the local high temperature will cause burns.

A method solved in the prior art is to install a fan near the heat source, and use a fan to accelerate the heat convection of the air to remove heat. The disadvantage of this heat dissipation method is that the fan It will occupy a certain space in the electronic device and affect the miniaturization of the electronic device.

In addition, in the prior art, the heat dissipating fins are mounted in surface contact on electronic components that generate high heat, and the high surface area of the heat dissipating fins dissipates heat into the air environment. However, the surface of the heat sink fin cannot be flattened as expected due to process limitations, so there is a gap between the heat sink fin and the electronic component, so that the heat dissipation performance is greatly reduced (due to the poor thermal conductivity of air).

Although a thermal interface material such as a thermal conductive paste or a thermal conductive paste is filled between the heat dissipation fin and the electronic component, the above problem can be solved. However, the soft thermal conductive material itself varies depending on temperature changes (evaporation due to high temperature, and curing shrinkage due to low temperature), resulting in failure to meet the durability requirements of the product.

The invention improves the structure of the heat sink, and the structural change and the layout design of the heat dissipation hole can effectively eliminate the heat generated by the thin electronic device during operation, thereby solving the problem of local high temperature, thereby improving the application of the thin electronic device. Sex and reliability.

According to an embodiment of the present invention, the composite heat sink includes a first substrate, a thermal diffusion radiation layer, and a second substrate. The thermal diffusion radiation layer is disposed on the first substrate and includes a carbon composite material. The second substrate is disposed on the thermal diffusion radiation layer, wherein a plurality of heat dissipation holes are formed in one of the first substrate and the second substrate.

In a variant embodiment, the second substrate has a contact area and two heat dissipation regions respectively located on opposite sides of the contact area, and the heat dissipation holes are distributed in the heat dissipation area of the second substrate.

In a variant embodiment, the first substrate has a central region and two heat dissipating regions respectively located on opposite sides of the central region, wherein the central region is located at an opposite side of the contact region, and the heat dissipation holes are further distributed in the The heat dissipation area of the first substrate. In a variant embodiment, the density of the heat dissipation holes away from the contact area of the second substrate is higher than the density of the heat dissipation holes adjacent to the contact area of the second substrate, and the density of the heat dissipation holes away from the central area of the first substrate A density higher than a heat dissipation hole adjacent to a contact area of the first substrate.

In a variant embodiment, the heat diffusion radiation layer comprises 30 to 70 parts by weight of the resin material and 25 to 50 parts by weight of the carbon composite based on 100 parts by weight.

In a variant embodiment, the carbon composite is one of a group consisting of diamond, artificial graphite, graphene, carbon nanotubes, carbon black and carbon fibers.

In a variant embodiment, the carbon composite has an average outer diameter of from 10 nm to 20 μm.

In a variant embodiment, more than 5 to 20 parts by weight of the radiation particles are contained.

In a variant embodiment, the radiant particles are metal particles, oxide particles or nitride particles, the radiant particles having an average particle size of from 3 μm to 20 μm.

In a variant embodiment, the first substrate, the thermally diffused radiation layer and the second substrate have a thickness ratio of 1:0.05 to 0.2:1.

According to the above composite heat sink, the present invention further provides a thermoelectric device comprising the above composite heat sink, a heat source body, a thermoelectric element and a power supply component, wherein the heat source system is connected to the second heat sink The substrate is connected to the first substrate of the composite heat sink, and the power supply element is electrically connected to the thermoelectric element.

In a variant embodiment, the thermoelectric element has a heat absorbing end, a discharge end and a plurality of thermocouple pairs between the heat absorbing end and the heat absorbing end, the heat absorbing end being connected to the first substrate of the composite heat sink The discharge end is electrically connected to the power supply element.

In a variant embodiment, the thermocouple pairs each comprise a p-type semiconductor component and an n-type semiconductor component.

The present invention has at least the following beneficial effects: the composite heat sink of the present invention can utilize a thermal diffusion layer (film) sandwiched between two metal substrates to form a heat source by utilizing heat conduction when in contact with a heat source body. Body heat is derived and from the bureau The area is uniformly diffused to the two sides of the circumference, and heat is radiated to the environment through the heat dissipation holes to achieve rapid heat dissipation.

Other objects and advantages of the present invention will be further understood from the technical features disclosed herein. The above and other objects, features, and advantages of the present invention will be apparent from

100a‧‧‧ mobile device

100b‧‧‧ thermoelectric device

1‧‧‧Composite heat sink

10‧‧‧First substrate

10a‧‧‧Central area

10b‧‧‧First heat sink area

101‧‧‧ vents

11‧‧‧ Thermal diffusion layer

111‧‧‧Resin materials

112‧‧‧Carbon composites

12‧‧‧second substrate

12a‧‧‧Contact area

12b‧‧‧second heat dissipation area

121‧‧‧ vents

13‧‧‧Fitting layer

14‧‧‧radiation particles

2‧‧‧heat source

3‧‧‧Shell

4‧‧‧Thermal components

41‧‧‧heat end

42‧‧‧Discharge end

43‧‧‧Thermal coupler pair

431‧‧‧p-type semiconductor components

432‧‧‧n type semiconductor components

5‧‧‧Power supply components

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view showing a composite heat sink according to a first embodiment of the present invention.

2A is a cross-sectional view of a composite heat sink according to a variation of the present invention.

2B is a cross-sectional view of a composite heat sink according to another variation of the present invention.

2C is a cross-sectional view of a composite heat sink according to still another variation of the present invention.

Figure 3 is a cross-sectional view of a mobile device to which the composite heat sink of the present invention is applied.

Figure 4 is a top plan view of a mobile device to which the composite heat sink of the present invention is applied.

Figure 5 is a top plan view of a thermoelectric device to which the composite heat sink of the present invention is applied.

The invention provides a composite heat sink applied to a thin electronic device, such as a mobile device, a tablet computer or a notebook computer, but is not limited thereto. According to the embodiment of the present invention, when the composite heat sink is in contact with the surface of the main heat source, the heat can be effectively extracted from the heat source, uniformly diffused to the whole and then radiated out, so as to achieve rapid and uniform heat dissipation.

[First Embodiment]

1 is a cross-sectional view of a composite heat sink according to a first embodiment of the present invention. The composite heat sink 1 of the present embodiment includes a first substrate 10, a heat diffusion radiation layer 11 and a second substrate 12. In this embodiment, the thermal diffusion radiation layer 11 is bonded between the first substrate 10 and the second substrate 12 by the bonding layer 13, and the material of the bonding layer 13 is, for example, a double-sided tape, a thermal adhesive or a penetrating agent; Preferably, the first substrate 10, the thermally diffused radiation layer 11 and the second substrate 12 have a thickness ratio of about 1:0.05 to 0.2:1. According to this, heat The diffusion radiation layer 11 can maintain good contact with the first substrate 10 and the second substrate 12, respectively, so that the heat dissipation effect of the composite heat sink 1 is better.

Specifically, the first substrate 10 and the second substrate 12 may be metal substrates, such as, but not limited to, aluminum, iron, or copper substrates, but the invention is not limited thereto. The heat diffusion radiation layer 11 comprises a resin material 111 and a carbon composite material 112. The composition of the heat diffusion radiation layer 11 of the present embodiment comprises about 30 to 70 parts by weight of the resin materials 111 and 25 to 100 parts by weight. 50 parts by weight of the carbon composite material 112; in a manner that a carbon composite material 112 having heat conduction and heat radiation capability is added to the resin material 111, and after being mixed and solidified, the heat diffusion radiation layer 11 is formed.

In the present embodiment, the resin material 111 may be, but not limited to, an epoxy resin, an acrylic resin, a urethane resin, a ruthenium rubber resin, a polyparaxylene resin, and a double malayan One of a group consisting of an amine resin and a polyimide resin. The carbon composite material 112 may be, but not limited to, one of a group consisting of diamond particles, artificial graphite particles, carbon black particles, carbon fiber particles, graphene sheets, and carbon nanotubes; preferably, the carbon composite material 112 The average outer diameter is between about 10 μm and 20 μm.

Furthermore, in order to provide the thermal diffusion radiation layer 11 with better heat radiation capability, the thermal diffusion radiation layer 11 of the present embodiment may further comprise one or more kinds of radiation particles 14 added in an amount of about 5 to 20 parts by weight. Further, the radiation particles 14 of the present embodiment may be, but are not limited to, metal particles, oxide particles or nitride particles. Wherein, the metal particles may be, but are not limited to, gold, silver, copper, nickel or aluminum particles, the oxide particles may be (but not limited to) aluminum oxide or zinc oxide particles, and the nitride particles may be, but are not limited to, nitrogen. Boron or aluminum nitride particles; preferably, the average particle size of the radiation particles 14 is between about 3 μm and 20 μm.

As described above, when the composite heat sink 1 of the present invention is in contact with a heat source body, the heat transfer can be performed by sandwiching a film having both heat diffusion and heat radiation functions between the two metal substrates. The method of conductively spreads the heat generated by the heat source body from the local area to the periphery uniformly, and then removes the heat from the metal substrate to the environment by means of heat radiation to achieve a uniform heat dissipation effect over a large area.

Referring to FIG. 2A to FIG. 2C, in a preferred embodiment, in order to remove heat to the environment more quickly, a plurality of heat dissipation holes may be further formed on the first substrate 10 and the second substrate 12 of the composite heat sink 1. 101, 121. For example, the heat dissipation holes 101 can be formed on the first substrate 10 (as shown in FIG. 2B); in detail, the first substrate 10 has a central region 10a and two opposite sides of the central region 10a. The first heat dissipation region 10b is disposed on the first heat dissipation region 10b of the first substrate 10.

Alternatively, the heat dissipation holes 121 may be formed on the second substrate 12 (as shown in FIG. 2A); in detail, the second substrate 12 has a contact region 12a for contacting the heat source body and two opposite portions respectively located at the contact region 12a. The second heat dissipation region 12b on the two sides, wherein the central region 10a of the first substrate 10 corresponds to the contact region 12a of the second substrate 12, and the heat dissipation holes 121 are distributed in the second heat dissipation region 12b of the second substrate 12. . Alternatively, the heat dissipation holes 101 and 121 may be distributed on the first heat dissipation region 10b of the first substrate 10 and the second heat dissipation region 12b of the second substrate 12 (as shown in FIG. 2C). It should be noted that the density of the heat dissipation holes 121 away from the contact area 12a of the second substrate 12 needs to be higher than the density of the heat dissipation holes 121 adjacent to the contact area 12a of the second substrate 12; likewise, away from the central area of the first substrate 10. The density of the heat dissipation holes 101 of 10a needs to be higher than the density of the heat dissipation holes 101 adjacent to the central portion 10a of the first substrate 10. Hereinafter, the specific effect of the layout design of the heat dissipation holes 101 and 121 of the present invention will be described by taking the composite heat sink 1 applied to the mobile device as an example.

Please refer to FIG. 3 , which is a cross-sectional view of a mobile device for applying the composite heat sink of the embodiment. As shown, the mobile device 100 a includes a heat source body 2 , the composite heat sink 1 , and an outer casing 3 . Please refer to FIG. 4 for a top view of the mobile device of the composite heat sink of the present embodiment.

The heat source body 2 is, for example, a central processing unit (CPU, generally the largest heat source in a thin electronic device), which can be fully bonded to the second substrate 12 by a double-sided tape, a thermal conductive adhesive or a penetrating agent (not shown). The contact area 12a covers the first substrate 10 with the outer casing 3. Thereby, the heat generated by the heat source body 2 during operation can be via the second substrate 12 The contact region 12a is led out to the thermal diffusion radiation layer 11, so that the thermal diffusion radiation layer 11 can be uniformly disposed between the first substrate 10 and the second substrate 12, and the heat is uniformly diffused from the local region to the peripheral side. Then, the heat dissipation holes 101 of the first heat dissipation region 10b of the first substrate 10 and the heat dissipation holes 121 of the second heat dissipation region 12b of the second substrate 12 are respectively radiated to the external environment, so that the heat of the heat source body 2 can be quickly removed, thereby avoiding If the operating temperature is too high, the heat source body 2 (central processing unit) may not operate, or the local temperature may be too high to cause burns.

Further, since the heat dissipation effect of the heat dissipation holes 101 and 121 is higher than that of the heat dissipation holes 101 and 121, the special layout design of the heat dissipation holes 101 and 121 (ie, closer to the first substrate) is adopted. The density of the heat dissipation holes on the two sides of the circumference of the second substrate is higher. When heat is uniformly diffused from the partial region of the heat diffusion radiation layer 11 toward the two sides of the circumference, a small amount of heat may first pass through the central region 10a. The heat dissipation holes 101, 121 of the contact region 12a are radiated to the external environment, so that most of the heat can be diffused toward both sides of the circumference, and is radiated to the external environment through the heat dissipation holes 101, 121 away from the central portion 10a and the contact portion 12a. The effect of comprehensive heat dissipation.

[Second embodiment]

Please refer to FIG. 5, which is a cross-sectional view of the thermoelectric device incorporating the above composite heat sink. The thermoelectric device 100b of the present embodiment includes the above-described composite heat sink 1, a heat source body 2, a pyroelectric element 4, and a power supply element 5.

In detail, the thermoelectric element 4 includes a heat absorbing end 41, a discharge end 42 and a plurality of thermocouple pairs 43 between the heat absorbing end 41 and the discharge end 42; wherein each thermocouple pair 43 comprises a p-type semiconductor element 431 And an n-type semiconductor device 432, the heat absorbing end 41 is connected to the first substrate 10 of the composite heat sink 1, and the discharge end 42 is electrically connected to the power supply element 5, and the electrical connection may be connected to each other or by Wire connection, but the invention is not limited thereto. In the present embodiment, the heat source body 2 is, for example, a central processing unit, and the power supply element 5 is, for example, a battery, but is not limited thereto.

Therefore, the composite heat sink 1 can heat the heat source body 2 during operation. Quickly transferred to the heat absorbing end 41 of the thermoelectric element 4, so that the thermoelectric element 4 can convert the heat into electrical energy, and further charge the power supply element 5 via the discharge end 42; in other words, the composite heat sink 1 of the present embodiment can enhance the thermoelectric element The photoelectric conversion efficiency of 4 can further maintain the high working efficiency of the thermoelectric device.

[Effect of the embodiment]

1. The thermal diffusion radiation layer of the present invention is made by mixing a resin material with a carbon composite material, wherein the carbon composite material is diamond particles, artificial graphite particles, carbon black particles, carbon fiber particles, graphene sheets, carbon nanotubes or The group, and thus the thermally diffused radiation layer, can have the ability to conduct heat and heat radiation. Furthermore, the thermal diffusion radiation layer may further incorporate one or more kinds of radiation particles, which are metal particles, oxide particles, nitride particles or a group thereof, to further enhance the surface heat radiation capability of the heat diffusion radiation layer.

2. The composite heat sink of the present invention adopts a structural design in which a thermal diffusion radiation layer (film) is sandwiched between two metal substrates, and heat of the heat source body can be derived by heat conduction when in contact with a heat source body, and It spreads uniformly from the local area to the two sides of the circumference, and uses heat radiation to remove heat to the environment for rapid heat dissipation.

3. The composite heat sink can be further provided with a specially distributed heat dissipation hole on the metal substrate (the density of the heat dissipation holes is higher in the region on the two sides of the circumference of the first substrate and the second substrate), when the heat is in heat During the process of diffusing a local area of the diffused radiation layer to the two sides of the circumference, since the heat dissipation holes near the central area and the contact area can only pass a small amount of radiant heat, most of the heat continues to diffuse toward the two sides of the circumference, thereby moving away from the central area. The vent hole of the contact area radiates to the external environment to achieve a large-area total heat dissipation effect.

4. The above composite heat sink can be applied to a thermoelectric device, and the heat generated by the heat source body during the working process can be transferred to the thermoelectric element more quickly, so as to improve the photoelectric conversion efficiency of the thermoelectric element, thereby maintaining the high work of the thermoelectric device. effectiveness.

However, the above description is only a preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, and equivalent structural changes made by using the present specification and the illustrated contents are equally included in the present invention. Within the scope of the agreement, Chen Ming.

1‧‧‧Composite heat sink

10‧‧‧First substrate

101‧‧‧ vents

11‧‧‧ Thermal diffusion layer

12‧‧‧second substrate

121‧‧‧ vents

Claims (12)

A composite heat sink comprising: a first substrate; a thermal diffusion radiation layer disposed on the first substrate and comprising a carbon composite material; and a second substrate disposed on the thermal diffusion radiation layer; a plurality of heat dissipation holes are formed in one of the first substrate and the second substrate; wherein a thickness ratio of the first substrate, the heat diffusion radiation layer and the second substrate is 1:0.05~0.2:1 . The composite heat sink of claim 1, wherein the second substrate has a contact area and two heat dissipation areas respectively located on opposite sides of the contact area, and the heat dissipation holes are distributed in the heat dissipation area of the second substrate. The composite heat sink of claim 2, wherein the first substrate has a central region and two heat dissipation regions respectively located on opposite sides of the central region, the central region being located at an opposite portion of the contact region, the heat dissipation The holes are further distributed in the heat dissipation area of the first substrate. The composite heat sink of claim 3, wherein a density of the heat dissipation holes away from the contact area of the second substrate is higher than a density of the heat dissipation holes adjacent to the contact area of the second substrate, and away from a central area of the first substrate The density of the louvers is higher than the density of the louvers adjacent to the contact area of the first substrate. The composite heat sink according to claim 1, wherein the heat diffusion radiation layer contains 30 to 70 parts by weight of the resin material and 25 to 50 parts by weight of the carbon composite based on 100 parts by weight. The composite heat sink of claim 5, wherein the carbon composite material is one of a group consisting of diamond, artificial graphite, graphene, carbon nanotubes, carbon black, and carbon fiber. The composite heat sink of claim 6, wherein the average outer diameter of the carbon composite material It is 10 nm to 20 μm. The composite heat sink according to claim 7 further comprises 5 to 20 parts by weight of the radiation particles. The composite heat sink according to claim 8, wherein the radiation particles are metal particles, oxide particles or nitride particles, and the radiation particles have an average particle diameter of from 3 μm to 20 μm. A thermoelectric device comprising: the composite heat sink according to claim 1; a heat source body connected to the second substrate of the composite heat sink; and a thermoelectric element connected to the composite heat sink a substrate; and a power supply component electrically connected to the thermoelectric component. The thermoelectric device of claim 10, wherein the thermoelectric element has a heat absorbing end, a discharge end, and a plurality of thermocouple pairs between the heat absorbing end and the heat absorbing end, the heat absorbing end being connected to the composite heat sink The first substrate is electrically connected to the power supply element. The thermoelectric device of claim 11, wherein the thermocouple pairs each comprise a p-type semiconductor element and an n-type semiconductor element.