TWI784468B - Heat dissipation structure - Google Patents

Abstract

An heat dissipation structure includes a circuit board, an electronic component, a heat generation component, a heat dissipation sheet, a liquid metal thermal grease and an insulative protection layer. The electronic component is located on the circuit board. The heat generation component is disposed on the circuit board. The heat dissipation sheet is disposed on the heat generation component, and the heat generation component is located between the heat dissipation sheet and the circuit board. The liquid metal thermal grease is disposed between the heat dissipation sheet and the heat generation component, and the heat dissipation sheet is thermally coupled to the heat generation component through the liquid metal thermal grease. The insulative protection layer is disposed between the heat dissipation sheet and the circuit board. The insulative protection layer encapsulates the electronic component, surrounds the electronic component and contacts a side surface of the electronic component.

Description

Heat dissipation structure

The present invention relates to a heat dissipation structure, and in particular to a heat dissipation structure applied to electronic devices.

With the continuous improvement of computing performance of electronic devices, how to quickly dissipate the heat generated by the central processing unit or graphics processor inside the electronic device during operation has always been a major research and development project of related manufacturers.

Generally speaking, the central processing unit or graphics processing unit is in contact with the heat sink, and the evaporation section of the heat pipe is in contact with the heat sink, so that the liquid working fluid in the evaporation section evaporates into a gaseous working fluid after absorbing heat. After that, the gaseous working fluid flows from the evaporating section to the condensing section, and the airflow generated by the fan operation is blown to the condensing section for heat exchange, so that the gaseous working fluid releases heat and condenses into a liquid working fluid, which flows back from the condensing section to the evaporating section.

At present, heat sinks are mostly fixed to CPUs or GPUs with thermal grease. Because liquid metal thermal grease has excellent thermal conductivity, it is gradually favored by related manufacturers. Due to the conductivity of the liquid metal heat dissipation paste, if the liquid metal heat dissipation paste is squeezed by the heat sink and overflows to the circuit board, it is very likely that the liquid metal heat dissipation paste will flow between the CPU or the graphics processor and the circuit board or The liquid metal thermal paste contacts the electronic components on the circuit board (such as wiring, passive components or electrical contacts) and causes a short circuit.

The invention provides a heat dissipation structure, which can avoid short circuit.

The invention proposes a heat dissipation structure, which includes a circuit board, an electronic component, a heating element, a heat dissipation sheet, a liquid metal heat dissipation paste and an insulating protective layer. Electronic components are located on the circuit board. The heating element is arranged on the circuit board. The cooling fin is arranged on the heating element, and the heating element is located between the cooling fin and the circuit board. The liquid metal heat dissipation paste is arranged between the heat sink and the heating element, and the heat sink is thermally coupled to the heat generation element through the liquid metal heat dissipation paste. The insulating protection layer is arranged between the heat sink and the circuit board. The insulating protective layer covers the electronic components. The insulating protective layer surrounds the heating element and contacts the side surface of the heating element.

Based on the above, the heat dissipation structure of the present invention is integrated with a short circuit protection design to prevent the overflowing liquid metal thermal paste from flowing between the heating element and the circuit board or the overflowing liquid metal thermal paste from contacting the electronic components on the circuit board (such as lines, passive components or electrical contacts).

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

FIG. 1 is a schematic top view of a heat dissipation structure according to an embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view of the heat dissipation structure in FIG. 1 along the section line I-I. Please refer to FIG. 1 and FIG. 2 , in this embodiment, the heat dissipation structure 100 can be applied to or be a part of an electronic device, and the electronic device can be a notebook computer. In detail, the heat dissipation structure 100 includes a circuit board 110, an electronic component 120, a heating element 130, a heat sink 140, a liquid metal heat dissipation paste 150, and an insulating protective layer 160, wherein the electronic component 120 can be a circuit on the circuit board 110, a passive component or electrical contacts, and the heating element 130 can be a central processing unit or a graphics processing unit.

The heating element 130 is disposed on the circuit board 110 and electrically connected to the circuit board 110 . The heat sink 140 can be copper heat sink, other metal heat sink or alloy heat sink, and is disposed above the circuit board 110 . The heating element 130 is located between the heat sink 140 and the circuit board 110 , and the heat sink 140 is thermally coupled to the heating element 130 . The liquid metal thermal paste 150 may be liquid copper thermal paste, but not limited thereto. The liquid metal thermal paste 150 is disposed between the heat sink 140 and the heating element 130 , wherein the heat sink 140 is thermally coupled to the heating element 130 through the liquid metal heat dissipation paste 150 , and fixed to the heating element 130 through the liquid metal heat dissipation paste 150 .

The insulating protection layer 160 is disposed between the heat sink 140 and the circuit board 110 , wherein the upper surface of the insulating protection layer 160 is connected to the heat sink 140 , and the lower surface of the insulating protection layer 160 is connected to the circuit board 110 . For example, the total thickness of the insulating protection layer 160 is substantially equal to the total thickness of the liquid metal thermal paste 150 and the heating element 130 . Further, the insulating protective layer 160 covers the electronic component 120 , and the insulating protective layer 160 surrounds the heating element 130 and contacts the side surface 131 of the heating element 130 .

If the liquid metal heat dissipation paste 150 is squeezed by the heat sink 140 to overflow, the path of the liquid metal heat dissipation paste 150 flowing to the circuit board 110 has been blocked by the insulating protection layer 160 . Therefore, the insulating protective layer 160 can prevent the liquid metal heat dissipation paste 150 from flowing to the circuit board 110 , avoiding the occurrence of the liquid metal heat dissipation paste 150 flowing between the heating element 130 and the circuit board 110 or the liquid metal heat dissipation paste 150 from contacting the electronic components on the circuit board 110 120 resulting in a short circuit.

Please refer to FIG. 2 , in this embodiment, the insulation protection layer 160 includes a first insulation protection portion 160a and a second insulation protection portion 160b connected to the first insulation protection portion 160a, wherein the first insulation protection portion 160a is connected to the heat sink 140, And the second insulating protection part 160 b is connected to the circuit board 110 . The first insulation protection part 160 a is located between the heat sink 140 and the second insulation protection part 160 b , and the second insulation protection part 160 b is located between the first insulation protection part 160 a and the circuit board 110 . Furthermore, the first insulating protection portion 160 a surrounds the heating element 130 and contacts the side surface 131 of the heating element 130 to prevent the liquid metal thermal paste 150 from flowing between the heating element 130 and the circuit board 110 . On the other hand, the second insulating protection portion 160 b covers the electronic component 120 to prevent the liquid metal thermal paste 150 from contacting the electronic component 120 on the circuit board 110 .

The insulating protection layer 160 has a groove 160c, wherein the heating element 130 is located in the groove 160c, and the electronic component 120 is located outside the groove 160c. The first insulation protection part 160a includes a first section located between the heat sink 140 and the second insulation protection part 160b and a second section extending into the groove 160c, and the second section contacts the side surface of the heating element 130 131.

In this embodiment, the first insulating protection part 160a includes a first adhesive layer 161a, a first insulating layer 162a and a second adhesive layer 163a, and the first insulating layer 162a is located between the first adhesive layer 161a and the second adhesive layer 163a. between. The first insulating layer 162a can be a sponge, wherein the first insulating layer 162a is connected to the heat sink 140 through the first adhesive layer 161a, and is connected to the second insulating protection portion 160b through the second adhesive layer 163a.

Further, the first insulating layer 162a includes a first extension section 164a extending into the groove 160c, and the second adhesive layer 163a includes a second extension section 165a extending into the groove 160c. The first extension section 164a is located between the heat sink 140 and the second extension section 165a, and the first extension section 164a and the second extension section 165a contact the side surface 131 of the heating element 130, thereby blocking the flow of the liquid metal thermal paste 150 to the circuit path of the board 110 . The first insulating layer 162a can be a sponge, because the sponge has pores, if the liquid metal heat dissipation paste 150 squeezed by the heat sink 140 flows to the first extension section 164a, the pores in the first extension section 164a can absorb the liquid metal heat dissipation paste 150 , to prevent the liquid metal thermal paste 150 from spreading to the circuit board 110 .

On the other hand, the geometric profiles of the first extension section 164a and the second extension section 165a are the same or similar, the second extension section 165a connects the side of the first extension section 164a facing the circuit board 110, and the first extension section 164a passes through the The extension section 165a is fixed on the circuit board 110 .

In detail, the first extension section 164 a and the second extension section 165 a turn toward the circuit board 110 and form a stepped structure 166 a. For example, the stepped structure 166a has a first stepped surface 1601 close to the heat sink 140, a second stepped surface 1602 close to the circuit board 110, and a stepped surface between the first stepped surface 1601 and the second stepped surface 1602 ( step height surface) 1603, wherein the second step surface 1602 contacts the side surface 131 of the heating element 130, and the step height surface 1603, the second step surface 1602 and the side surface 131 of the heating element 130 form a depression 167a. If the liquid metal thermal paste 150 squeezed by the heat sink 140 flows toward the circuit board 110 , the recess 167 a can be used to collect the liquid metal thermal paste 150 .

In this embodiment, the second insulating protection part 160b includes a second insulating layer 161b and a third adhesive layer 162b, wherein the second insulating layer 161b is located between the second adhesive layer 163a and the third adhesive layer 162b, and the third adhesive layer Layer 162b connects circuit board 110 . The second insulating layer 161b can be made of polyester film (Mylar ^® ), wherein the second insulating layer 161b covers the top surface of the electronic component 120 and is fixed to the circuit board 110 through the third adhesive layer 162b. On the other hand, the third adhesive layer 162b covers the side of the electronic component 120 , so the second insulating layer 161b and the third adhesive layer 162b can prevent the liquid metal thermal paste 150 from contacting the electronic component 120 on the circuit board 110 .

Please refer to FIG. 1, in this embodiment, the heat dissipation structure 100 further includes a heat pipe 170 and a fan 180, wherein the heat pipe 170 has an evaporation section 171 and a condensation section 172, the evaporation section 171 is connected and thermally coupled to the heat sink 140, and the fan 180 is Quasi-condensing section 172. Therefore, the heat generated by the heating element 130 can be transferred to the evaporating section 171 of the heat pipe 170 via the heat sink 140 , so that the liquid working fluid in the evaporating section 171 evaporates into a gaseous working fluid after absorbing heat. Afterwards, the gaseous working fluid flows from the evaporating section 171 to the condensing section 172, and the airflow generated when the fan 180 is running is blown to the condensing section 172 for heat exchange, so that the gaseous working fluid releases heat and condenses into a liquid working fluid and flows from the condensing section 172 Flow back to the evaporation section 171.

In summary, in the heat dissipation structure of the present invention, the insulating protective layer surrounds the heating element and contacts the side surface of the heating element, so the insulating protective layer can prevent the liquid metal thermal paste squeezed by the heat sink from flowing to the circuit board, avoiding the occurrence of liquid The metal heat dissipation paste flows between the heating element and the circuit board or the liquid metal heat dissipation paste contacts the electronic components (such as lines, passive components or electrical contacts) on the circuit board, resulting in a short circuit.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some changes and modifications without departing from the spirit and scope of the present invention. The scope of protection of the present invention should be defined by the scope of the appended patent application.

100: heat dissipation structure 110: circuit board 120: Electronic components 130: heating element 131: side surface 140: heat sink 150: liquid metal thermal paste 160: insulating protective layer 160a: the first insulation protection part 161a: the first adhesive layer 162a: first insulating layer 163a: Second adhesive layer 164a: first extension 165a: second extension 166a ladder-like structure 167a: Depression 160b: the second insulation protection part 161b: second insulating layer 162b: The third adhesive layer 160c: Groove 1601: first-order surface 1602: second order surface 1603: Step height 170: heat pipe 171: Evaporation section 172: condensation section 180: fan

FIG. 1 is a schematic top view of a heat dissipation structure according to an embodiment of the present invention. FIG. 2 is a schematic partial cross-sectional view of the heat dissipation structure in FIG. 1 along the section line I-I.

110: circuit board 120: Electronic components 130: heating element 131: side surface 140: heat sink 150: liquid metal thermal paste 160: insulating protective layer 160a: the first insulation protection part 161a: the first adhesive layer 162a: first insulating layer 163a: Second adhesive layer 164a: first extension 165a: second extension 166a ladder-like structure 167a: Depression 160b: the second insulation protection part 161b: second insulating layer 162b: The third adhesive layer 160c: Groove 1601: first-order surface 1602: second order surface 1603: Step height 170: heat pipe 171: Evaporation section

Claims (10)

A heat dissipation structure, comprising: a circuit board; electronic components located on the circuit board; heating elements arranged on the circuit board; heat sinks arranged on the heating element, and the heating element is located between the heat sink and the circuit board between the liquid metal thermal paste, arranged between the heat sink and the heating element, and the heat sink is thermally coupled to the heating element through the liquid metal heat dissipation paste; and an insulating protective layer, arranged between the heat sink and the circuit board between, and includes a first insulation protection part and a second insulation protection part, the first insulation protection part surrounds the heating element and contacts the side surface of the heating element, the second insulation protection part covers the electronic component, wherein the The first insulation protection part is located between the heat sink and the second insulation protection part, and the second insulation protection part is located between the first insulation protection part and the circuit board, and the first insulation protection part is blocked from the Between the heating element and the second insulating protection part. The heat dissipation structure according to claim 1, wherein the electronic component includes a circuit, a passive component or an electrical contact. The heat dissipation structure according to claim 1, wherein the heating element includes a central processing unit or a graphics processing unit. The heat dissipation structure according to claim 1, wherein the first insulation protection part is connected to the second insulation protection part, the first insulation protection part is connected to the heat sink, and the second insulation protection part is connected to the circuit board. The heat dissipation structure according to claim 4, wherein the first insulating protection part includes a first adhesive layer, a first insulating layer and a second adhesive layer, and the first insulating layer is located between the first adhesive layer and the second adhesive layer. Between the layers, the first adhesive layer is connected to the heat sink, and the second adhesive layer is connected to the second insulating protection part. The heat dissipation structure according to claim 5, wherein the insulating protective layer has a groove, and the heating element is located in the groove, the first insulating layer includes a first extension extending into the groove, and the first The second glue layer includes a second extension section extending into the groove, and the first extension section and the second extension section contact the side surface of the heating element. The heat dissipation structure according to claim 6, wherein the second extension section is connected to a side of the first extension section facing the circuit board, and the first extension section is fixed to the circuit board through the second extension section. The heat dissipation structure according to claim 6, wherein the first extension section and the second extension section turn toward the circuit board and form a stepped structure. The heat dissipation structure according to claim 5, wherein the second insulating protection part includes a second insulating layer and a third adhesive layer, the second insulating layer is located between the second adhesive layer and the third adhesive layer, and the The third adhesive layer connects the circuit board. The heat dissipation structure according to claim 1 further includes a heat pipe and a fan, wherein the heat pipe has an evaporating section and a condensing section, the evaporating section is connected to the heat sink, and the fan is aligned with the condensing section.

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