WO2021088654A1

WO2021088654A1 - Heat dissipation device and circuit board heat dissipation structure

Info

Publication number: WO2021088654A1
Application number: PCT/CN2020/122884
Authority: WO
Inventors: 陈磊
Original assignee: 中兴通讯股份有限公司
Priority date: 2019-11-08
Filing date: 2020-10-22
Publication date: 2021-05-14
Also published as: CN112788911A

Abstract

Provided are a heat dissipation device and a circuit board heat dissipation structure. The heat dissipation device comprises a connecting frame and heat dissipation units, wherein a plurality of heat dissipation units are provided, with gaps being provided between the plurality of heat dissipation units; the connecting frame is separately connected to the plurality of heat dissipation units by means of elastic connectors; the plurality of heat dissipation units can float up and down relative to the connecting frame; and the connecting frame is further provided with a mounting hole, the mounting hole being used for a fastener to pass therethrough such that the connecting frame is connected to a circuit board where a heat generation element is located. The circuit board heat dissipation structure comprises a circuit board provided with a plurality of chips, and the heat dissipation device.

Description

Heat sink and circuit board heat dissipation structure

Technical field

The present disclosure relates to but not limited to heat dissipation technology, and more specifically, to a heat sink and a circuit board heat dissipation structure.

Background technique

As the power consumption of chips and single boards of communication equipment increases, the space of single boards and plug-in boxes cannot increase in proportion, resulting in an increase in power density, and therefore higher and higher heat dissipation requirements. At the same time, the single-board multi-chip layout requires uniform temperature and heat dissipation to avoid poor local heat dissipation conditions and lead to chip overheating. The traditional fixed-distance uniform temperature radiator solution is shown in Figure 1. The radiator 1 is fixed on the liner (not shown) through the single plate 4 through the screw 2 and the fixed-distance pressure riveting stud 3, and multiple chips Share a radiator. The heat-conducting mud is respectively filled between the heat sink substrate and each chip to dissipate heat for the chips on the single board. However, due to the poor heat dissipation of the thermal mud itself and the high power consumption of the main chip, the junction temperature of the main chip will increase. If a heat sink is used for each chip to dissipate heat, the screws used by the heat sink will take up a large amount of board area and cause wiring difficulties.

Public content

The following is an overview of the subject matter described in detail in this disclosure. This summary is not intended to limit the scope of protection of the claims.

The embodiment of the present disclosure provides a heat sink, which includes a connecting frame and a heat dissipating unit. There are multiple heat dissipating units, and there is a gap between the plurality of heat dissipating units. The connecting frame and a plurality of heat dissipating units The monomers are respectively connected by elastic connectors, and a plurality of the heat dissipation monomers can respectively float up and down relative to the connecting frame, and the connecting frame is also provided with mounting holes, and the mounting holes are used to allow fasteners to pass through. Connect the connecting frame with the circuit board where the heating element is located.

The embodiment of the present disclosure also provides a circuit board heat dissipation structure, including:

A circuit board, a plurality of chips are arranged on one side of the circuit board; and

According to the radiator of the embodiment of the present disclosure, the connecting frame of the radiator is connected to the circuit board by a fastener, and a plurality of the heat dissipation units are located between the connecting frame and the circuit board. Each of the heat dissipation monomers is lifted up by the corresponding chip and used to dissipate heat for the chip.

In the heat dissipation structure of the heat sink and the circuit board of the embodiment of the present disclosure, multiple heat dissipation monomers can float up and down, so that the gap between the heating element and the heat sink is small, temperature loss can be reduced, and heat dissipation efficiency can be improved. However, since the multiple heat dissipation units are connected to the circuit board through the connecting frame instead of being connected to the circuit board separately, fewer fasteners need to be used, and the influence on the wiring of the circuit board is small.

The heat sink and circuit board heat dissipation structure of the embodiments of the present disclosure can be used in communication products or electronic products to provide heat dissipation for multiple chips.

After reading and understanding the drawings and detailed description, other aspects can be understood.

Description of the drawings

Figure 1 is a schematic diagram of a fixed-distance uniform temperature radiator.

Fig. 2 is a three-dimensional schematic diagram of a heat sink provided by an exemplary embodiment of the present disclosure.

Fig. 3 is an enlarged view of part A in Fig. 2.

FIG. 4 is a three-dimensional schematic diagram of a circuit board heat dissipation structure provided by an exemplary embodiment of the present disclosure.

Fig. 5 is a cross-sectional view of a circuit board heat dissipation structure provided by an exemplary embodiment of the present disclosure.

Detailed ways

The present disclosure describes a number of embodiments, but the description is exemplary rather than restrictive, and it is obvious to a person of ordinary skill in the art that the embodiments described in the present disclosure may There are more examples and implementation schemes. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Except when specifically limited, any feature or element of any embodiment can be used in combination with any other feature or element in any other embodiment, or can replace any other feature or element in any other embodiment.

An exemplary embodiment of the present disclosure provides a heat sink 100 which is not mounted on a circuit board. Please refer to FIG. 2, which includes a connecting frame 40 and a heat dissipation unit, and there are multiple heat dissipation units. In the example in the figure, three heat dissipation units are shown, namely, the first heat dissipation unit 10, the second heat dissipation unit 20, and the third heat dissipation unit 30. However, the number of heat dissipation units in the present disclosure is not limited and can be According to the actual working conditions, for example, the number of heat dissipation monomers can also be 2, 4, 5 or more. The circuit board of this embodiment has three chips with relatively high power consumption, so it is considered to use three heat sinks to dissipate heat. In this embodiment, there is a gap between the plurality of heat dissipation units, the connection frame 40 and the plurality of heat dissipation units are respectively connected by elastic connectors, and the plurality of heat dissipation units can respectively float up and down relative to the connection frame 40. In one example, the connecting frame 40 is an integral connecting frame, that is, it is not composed of multiple discrete parts. The first heat dissipation unit 10, the second heat dissipation unit 20, and the third heat dissipation unit 30 are arranged side by side with a gap between them.

Taking FIG. 2 as an example, the distance between the first heat dissipation unit 10, the second heat dissipation unit 20, and the third heat dissipation unit 30 and the connecting frame 40 decreases when they float upward, and the distance between the first heat dissipation unit 10, the second heat dissipation unit 20 and the third heat dissipation unit 30 and the connection frame 40 when they float downward. The distance between them increases, and different heat dissipation units float separately. Therefore, when the first heat dissipation unit 10, the second heat dissipation unit 20, and the third heat dissipation unit 30 are lifted up by the heating element such as a chip on the circuit board, If the height of the chip itself is different, the distance between the heat dissipation unit and the connecting frame 40 will also be different, which makes the gap between each chip and the corresponding heat sink very small, which can reduce temperature loss and improve heat dissipation efficiency.

As shown in FIG. 2, the connecting frame 40 of this embodiment is also provided with a mounting hole 41. The mounting hole 41 is used to allow fasteners to pass through and connect the connecting frame 40 to the circuit board (such as a single board) where the heating element is located. . The connected structure can be seen in Figure 4 and Figure 5. Since a plurality of heat dissipation units are connected to the circuit board through the connecting frame 40 instead of being connected to the circuit board separately, fewer fasteners need to be used, and the influence on the wiring of the circuit board is small.

In the example of FIG. 2, the connecting frame 40 is a rectangular metal frame, which can be made of aluminum plate, aluminum alloy plate, hot-dip galvanized sheet, etc. The strength of the metal frame can be selected according to the size and weight of the heat dissipation unit. In FIG. 2, a reinforcing plate perpendicular to the long sides is arranged between the two long sides of the metal frame, and the mounting holes 41 are arranged on the corner area of the metal frame and the reinforcing plate. In the figure, one mounting hole is set in each of the four corner areas of the metal frame, and two mounting holes are set in each of the two reinforcing plates. In other examples, according to the needs of the number and strength of the heat dissipation unit, the reinforcing plate may not be provided, or one, three or more reinforcing plates may be provided. When the reinforcing plate is not provided, four mounting holes can be provided only in the corner area of the metal frame, or can also be provided at other positions on the two sides or four sides of the metal frame except for the corner area. It should be noted that the metal frame shown in FIG. 2 is only an example, and a non-metal frame or other types of connecting frames are also possible.

For the situation where Figure 2 includes 3 heat sinks, if the 4 corners of each heat sink are connected to the circuit board with 4 fasteners, a total of 12 fasteners are required, and the same must be provided on the circuit board. The number of mounting holes occupies a larger wiring area of the circuit board. After the connection frame is used, the fasteners required to be used are reduced. In Figure 2, 8 solid parts are used to realize the connection between the connection frame and the circuit board. When the strength is sufficient, the number of mounting holes on the reinforcing plate or the reinforcing plate can be reduced, so that fewer fasteners need to be used. Therefore, the occupation of the wiring area of the circuit board can be reduced, and the heat sink of this structure has little influence on the wiring of the circuit board. At the same time, since the connection between the heat dissipation single board and the connecting frame can be completed in advance, it is more convenient and quicker to install the heat sink on the circuit board.

It should be noted that the shape and material of the connecting frame are not limited to the solutions adopted in the above embodiments. The shape and size can be set reasonably according to the size of the veneer, and the material can also be sheet metal, stainless steel, die-casting, etc.

In this embodiment, the heat dissipation units all include a substrate and a heat dissipation structure arranged on one side of the substrate, and the connecting frame is located on the side of the heat dissipation unit where the heat dissipation structure is located. In the example shown in FIG. 2, the first heat dissipation unit 10 includes a first substrate 11 and a first fin 12, the second heat dissipation unit 20 includes a second substrate 21 and a second fin 22, and the third heat dissipation unit 30 It includes a third substrate 31 and a third fin 32. A gap is provided between the first substrate 11 and the second substrate 21 and between the second substrate 21 and the third substrate 31. The connecting frame 40 is located on the heat dissipation structure on the heat dissipation unit, that is, on the side where the fins are located. As shown in FIG. 2, it is above the fins.

In the example of FIG. 2, the left side of the metal frame extends beyond the heat dissipation veneer 10, and the fasteners passing through the two mounting holes 41 on the left side can be directly connected to the circuit board without wearing Over-heating veneer. However, the fasteners that pass through the mounting holes 41 on the two reinforcing plates need to pass through the heat dissipation single board and then connect to the circuit board. Therefore, the substrate of the heat dissipation unit needs to be provided with one or more escape holes (not shown in the figure). Out), the escape holes correspond to the positions of the corresponding mounting holes on the connecting frame 40, so that the fasteners passing through the mounting holes 41 can pass through to connect the connecting frame 100 with the circuit board. In another example, if the corner areas of the metal frame all extend beyond the heat dissipation veneer without a reinforcing plate, or the position of the mounting hole on the reinforcing plate is also outside the heat dissipation unit, the heat dissipation veneer There is no need to provide escape holes on the substrate.

In an exemplary embodiment of the present disclosure, the elastic connecting piece includes an elastic piece and a connecting piece. Two ends of the elastic piece abut on the connecting frame and the heat dissipation unit respectively, and the connecting piece passes through the connecting piece. The elastic member connects the connection frame and the heat dissipation unit, so that the heat dissipation unit can float up and down relative to the connection frame within a set range. In an example, a plurality of first connecting holes are provided on the connecting frame, and a second connecting hole corresponding to the position of the first connecting hole is provided on the substrate of each heat dissipating unit. The first connecting hole and the second connecting hole are The hole is used for the connecting piece to pass through to connect the connecting frame and the heat dissipation unit.

Fig. 3 is an enlarged view of part A in Fig. 2, using a spring 72 as an elastic member, and a screw 71 and a pressure riveting stud 73 as a connecting member. As shown in FIG. 3, the screw 71 passes through the base plate 11 of the heat sink unit, the spring 72 and the connecting frame 40 in sequence and is matched with the pressure riveting stud 73. The pressure riveting stud 73 is riveted with the connecting frame 40. The two ends of the spring 72 are respectively riveted. It rests on the connecting frame 40 and the base plate 11. This structure can float and fix three heat-dissipating monomers on the connecting frame, and then the combination of the connecting frame and the heat-dissipating monomers can be arranged on the circuit board together through the lining board.

In a natural state, due to the elastic force of the spring 72, the distance between the connection frame 40 and the heat dissipation unit (which can be represented by the distance between the connection frame 40 and the substrate 11) reaches a maximum value. When the heat sink 100 is mounted on the circuit board, refer to FIG. 5. At this time, the chip is in contact with the bottom of the substrate 11 of the heat sink unit, and the heat sink unit is lifted up, and the spring 72 is compressed so that the distance between the connecting frame 40 and the heat sink unit Compressed to a minimum, and the three heat sinks can float up and down respectively to ensure effective contact between the chip and the heat sink substrate.

The above-mentioned connecting structure is only exemplary. The connecting pieces in FIG. 2 are connected by screws, but other connecting pieces, such as bolt connections, rivet connections, etc., may also be used. In the case of screw connection, the connecting frame can be riveted with pressure riveting studs, can also be made into an integral form with the studs, or in the form of sheet metal punching bridges, and so on. In another example, the structure of the combination of the elastic member and the connecting member can also be replaced by a floating spring screw. In addition, the spring can also be replaced with other elastic parts. The main factors affecting the diameter and length of the spring spiral are the weight and size of the radiator, the size of the space where the spring is placed, and the size of the pressure riveting stud. For the heat sink with spring, the spring force should be less than the allowable force of the chip to avoid crushing the chip.

Those skilled in the art will know that the number and layout of the connecting pieces are not limited to those shown in Figure 2 and need to be set reasonably according to the mechanical properties. For example, when the weight of the heat sink is less than 150g, only two connecting pieces are needed to install it on the connecting frame. Above, when the weight of the heat dissipation unit is greater than 150g, 4 or more connectors can be used, which are generally arranged symmetrically to ensure uniform force.

Figures 4 and 5 show a circuit board heat dissipation structure provided by an exemplary embodiment of the present disclosure. The circuit board is a single board. The structure includes a single board 50 and the heat sink 100 according to the embodiment of the present disclosure. One side of the single board 50 is provided with multiple chips; and the connecting frame 40 of the heat sink 100 is connected to the single board 50 by fasteners, and multiple heat dissipation units are located between the connecting frame 40 and the circuit board 50. The bodies, namely, the first heat dissipation unit 10, the second heat dissipation unit 20, and the third heat dissipation unit 30 in FIG. 2 are respectively lifted up by the corresponding chips to dissipate heat for the chips.

When designing the heat dissipation structure, a certain amount of interference can be left, which will be greater than the sum of the manufacturing tolerance and assembly tolerance of the chip, thus ensuring that when the heat sink is installed on the single board, the corresponding chip will squeeze and dissipate heat The substrate of the monomer makes the heat dissipation monomer float up and down to ensure that the gap between the chip and the heat sink is small, such as less than 0.2mm, so thermally conductive silicone grease or thinner thermally conductive materials can be used to fill the gap to reduce temperature loss , Improve heat dissipation efficiency.

The circuit board heat dissipation structure shown in FIGS. 4 and 5 also includes a backing plate 60, which is located on the side of the single board 50 away from the heat sink 100, and the fasteners pass through the mounting holes on the connecting frame 40 and the single board. After the installation hole, it is fixedly connected with the liner 60. In one example, the screw 74 passes through the metal frame 40, the riveting stud 75 riveted to the connecting frame, and the veneer 50 and then is screwed to the riveting nut 76 on the liner 60, thereby mounting the heat sink 100 on the veneer 50 up.

The above-mentioned heat dissipation unit is not limited to a uniform temperature plate radiator, and may also be a common profile radiator, a heat pipe radiator, etc. In addition, when the uniform temperature plate radiator is used, it is not limited to the radiator shown in FIG. 2, and may also be a Z-shaped or C-shaped uniform temperature plate radiator.

In the description of the present disclosure, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. ; It can be directly connected or indirectly connected through an intermediary. For those of ordinary skill in the art, the specific meaning of the above-mentioned terms in the present disclosure can be understood according to specific circumstances. In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that specific features, structures, materials, or characteristics described in conjunction with the embodiment or examples are included in the present disclosure In at least one embodiment or example. In this specification, the schematic representation of the above-mentioned terms does not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner. Although the implementation manners disclosed in the present disclosure are as above, the content described is only the implementation manners used for facilitating the understanding of the present disclosure, and is not intended to limit the present disclosure. Anyone skilled in the art to which this disclosure belongs can make any modifications and changes in the implementation form and details without departing from the spirit and scope disclosed in this disclosure. However, the scope of patent protection of this disclosure still requires The scope defined by the appended claims shall prevail.

Claims

A heat sink includes a connecting frame and a heat dissipating unit. The heat dissipating unit has a plurality of units with gaps between the plurality of heat dissipating units. The connecting rack and the plurality of heat dissipating units pass through elastic connecting pieces. Are connected separately, a plurality of the heat dissipation monomers can respectively float up and down relative to the connecting frame, the connecting frame is also provided with mounting holes, and the mounting holes are used to allow fasteners to pass through to connect the connecting frame with The circuit board connection where the heating element is located.
5. The heat sink of claim 1, wherein the connecting frame is an integral connecting frame, and there are 2 or more than 3 heat dissipation units.
The heat sink according to claim 2, wherein the connecting frame is a rectangular metal frame, and the mounting holes are provided in the corner area of the metal frame; or, the connecting frame is a rectangular metal frame, so A reinforcing plate perpendicular to the long side is arranged between the two long sides of the metal frame, and the mounting holes are arranged on the corner area of the metal frame and the reinforcing plate.
The heat sink according to any one of claims 1 to 3, wherein the heat dissipation unit comprises a substrate and a heat dissipation structure provided on one side of the substrate, and the connecting frame is located on the heat dissipation unit. The side of the structure.
The heat sink according to claim 4, wherein the substrate of the heat dissipation unit is provided with one or more avoiding holes, and the avoiding holes correspond to the positions of at least part of the mounting holes on the connecting frame for providing The fastener passing through the mounting hole passes through to connect the connecting frame with the circuit board.
The heat sink according to claim 4, wherein the elastic connecting piece comprises an elastic piece and a connecting piece, and two ends of the elastic piece abut on the connecting frame and the heat dissipation unit respectively, and the connecting A piece passes through the elastic piece to connect the connection frame and the heat dissipation unit, and the heat dissipation unit can float up and down relative to the connection frame within a set range.
The heat sink according to claim 6, wherein the connecting frame is provided with a plurality of first connecting holes, and the substrate of each heat dissipating unit is provided with a second connecting hole corresponding to the position of the first connecting hole The first connecting hole and the second connecting hole are used for the connecting member to pass through to connect the connecting frame and the heat dissipation unit.
A circuit board heat dissipation structure, including:

A circuit board, a plurality of chips are arranged on one side of the circuit board; and

The radiator according to any one of claims 1 to 7, wherein the connecting frame of the radiator is connected to the circuit board by a fastener, and a plurality of the heat dissipation units are located on the connecting frame and the circuit board In between, a plurality of the heat dissipation monomers are respectively lifted up by the corresponding chips for dissipating heat for the chips.
8. The circuit board heat dissipation structure according to claim 8, wherein the gap between the heat dissipation unit and the chip is less than 0.2 mm, and the gap is filled with a thermally conductive material.
The circuit board heat dissipation structure according to claim 8 or 9, wherein the circuit board heat dissipation structure further comprises a backing plate, the backing plate is located on a side of the circuit board away from the heat sink, and the fastener After passing through the mounting hole on the connecting frame and the mounting hole on the circuit board, it is fixedly connected with the liner board.