CN217363378U

CN217363378U - Mounting structure of PCB board and radiator

Info

Publication number: CN217363378U
Application number: CN202120578545.6U
Authority: CN
Inventors: 汤郑; 熊建波; 陈杨; 李承栋
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-03-22
Filing date: 2021-03-22
Publication date: 2022-09-02
Anticipated expiration: 2031-03-22

Abstract

The utility model provides a PCB board and mounting structure of radiator is installing the in-process of PCB board with radiator, chip, has avoided the chip because of the inhomogeneous damage condition such as crackle that appears of atress, and unusual junction temperature can not appear in the chip moreover. The above-mentioned mounting structure includes: PCB board, radiator, chip, the lower surface subsides of chip are located the PCB board, and the upper surface subsides of chip locate the lower surface of radiator, its characterized in that, mounting structure still includes: screw structures, springs; the spring is sleeved on the screw structure, the length of the spring in a natural state is a first value, and the second end of the screw structure is in threaded connection with a threaded hole of the PCB; when the spring is subjected to the target pressure, the spring length of the spring is adjusted from a first value to a second value to push the heat sink to press the chip.

Description

Mounting structure of PCB board and radiator

Technical Field

The utility model relates to a heat dissipation technical field, concretely relates to mounting structure of PCB board and radiator.

Background

During use of the electronic device, a chip disposed on a Printed Circuit Board (PCB) generates a large amount of heat during operation. To solve this problem, a heat sink needs to be added to the chip. Generally, a heat sink may be fixed to a chip using a heat conductive material having an adhesive function.

In the existing mounting structure, a spring screw for fastening the heat sink and the PCB board and a spring for providing a pressure for attaching the chip are pre-mounted on the heat sink, and then integrated with the heat sink. However, in the installation process, the heat sink is firstly placed on the chip, then after the spring screw is compressed by external force, the spring is driven to press the heat sink downwards to the chip, and the threaded end part at the bottom of the spring screw is screwed into the threaded hole, so that the whole process of assembling the heat sink on the single plate is realized. In the process of screwing the threaded end portion of the bottom portion of the spring screw into the threaded hole, since the length of the threaded end portion of the bottom portion of the spring screw is small, it should be possible to screw the threaded end portion into the threaded hole by applying a larger external force. However, when the spring is driven by a larger external force applied to press the heat sink down against the chip, a larger instantaneous stress is easily generated, which causes stress concentration at a certain corner of the chip, not only the problem of corner damage of the chip occurs, but also uneven stress of the TIM1.5 material in the compression and expansion process is caused, so that the temperature of the chip is abnormally increased.

Therefore, how to solve the current situation that the stress of the whole mounting structure is not uniform in the assembling process due to the generation of transient stress in the mounting process and reduce the abnormally increased temperature of the chip become a problem which needs to be solved in the present stage.

Disclosure of Invention

The utility model provides a PCB board and mounting structure of radiator is installing the in-process of PCB board with radiator, chip, has avoided the chip because of the inhomogeneous damage condition such as crackle that appears of atress, and unusual junction temperature can not appear in the chip moreover.

In a first aspect, the utility model provides a mounting structure of PCB board and radiator, mounting structure includes the PCB board radiator, chip, the lower surface subsides of chip are located the PCB board, the upper surface subsides of chip are located the lower surface of radiator, a serial communication port, mounting structure still includes: screw structures, springs; the screw structure penetrates through the radiator, the spring is sleeved on the screw structure, the length of the spring in a natural state is a first value, and a second end of the screw structure is in threaded connection with a threaded hole of the PCB; when the spring is subjected to the target pressure, the spring length of the spring is adjusted from the first value to a second value so as to push the heat sink to press the chip.

Optionally, in some examples, the mounting structure further includes a nut, the screw structure includes a double male screw, the double male screw includes a first threaded end, a second threaded end, and a first threaded polished rod, the first threaded end is in threaded connection with the threaded hole of the PCB board, a distance between the second threaded end and the lower surface of the heat sink is the first value, and the spring is sleeved on the first threaded polished rod; threading the nut into the second threaded end to subject the spring to the target pressure.

Optionally, in some examples, the nut is threaded into the second threaded end a preset number of turns.

Optionally, in some examples, the double male screw further comprises a stop surface for setting a distance between the nut and the heat sink to the second value when the nut is threaded into the second threaded end to the first threaded polish rod.

Optionally, in some examples, the screw structure includes a spring screw including a third threaded end and a second threaded polish rod, the spring sleeve being disposed on the second threaded polish rod, the second threaded polish rod being connected with the second threaded end; when the spring is subjected to the target pressure, the second threaded polish rod with the length meeting a first preset range drives the third threaded end part to be screwed into the threaded hole of the PCB; or when the spring is subjected to the target pressure, the third threaded end part with the length meeting a second preset range is screwed into the threaded hole of the PCB.

Optionally, in some examples, a thermally conductive material is disposed between the heat spreader and the chip.

According to the technical scheme, the utility model has the advantages of it is following:

the utility model discloses in, because the second end of screw structure is prior to be threaded connection with the screw hole of PCB board, can play the effect that provides the strong point of a bottom atress, receive target pressure at the spring so, when adjusting spring length from the first value to the second value, can promote the radiator and sticis the chip, make certain angle of chip can not produce stress concentration, and then with the radiator, the in-process of chip mounting to PCB board, the damaged condition such as crackle has been avoided because of the atress is inhomogeneous to the chip, and unusual junction temperature can not appear in the chip.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application.

Fig. 1 is a front view of a mounting structure of a PCB board and a heat sink according to a conventional solution;

FIG. 2 is a schematic diagram of a chip with corner damage;

fig. 3 is a schematic view illustrating an installation structure of a PCB and a heat sink according to an embodiment of the present disclosure;

FIG. 4a is a schematic view of another mounting structure provided in embodiments of the present application;

FIG. 4b is a schematic view of a dual male screw provided in an embodiment of the present application;

FIG. 4c is a schematic view of another alternative dual male screw provided by an embodiment of the present application;

FIG. 5a shows a schematic view of a dual male screw provided by the present application secured to a PCB board;

fig. 5b shows a schematic view of the heat sink provided by the present application threaded through a double male screw;

FIG. 5c shows a schematic view of the spring sleeve provided herein over a bi-male screw;

FIG. 5d shows a schematic view of the present application providing a nut threaded into a hermaphroditic screw;

FIG. 6 is a schematic view of another mounting structure provided in embodiments of the present application;

fig. 7 is a schematic structural diagram of a spring screw according to an embodiment of the present application.

Detailed Description

The terms "first," "second," "third," "fourth," and the like in the description and in the claims of the present application and in the drawings described above, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Embodiments of the present application will now be described with reference to the accompanying drawings, and it is to be understood that the described embodiments are merely illustrative of some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 1 is a front view showing a mounting structure of a PCB board and a heat sink according to a conventional solution. In the conventional mounting structure, the spring screw 12 for fastening the heat sink 30 and the PCB board 20 and the spring 50 for providing a contact pressure with the chip 40 are pre-mounted on the heat sink 30, and thus are integrated with the heat sink 30; wherein spring screw 12 includes a second threaded polish rod 121 and a third threaded end 120. However, during the mounting process, the heat sink 30 is first placed on the chip 40, and then after the spring screws 12 are compressed by an external force, the springs 50 are driven to press the heat sink 30 down against the chip 40, and the third threaded end 120 is screwed into the threaded hole, so that the whole process of assembling the heat sink 30 on the PCB is achieved. In the process of screwing the third threaded end portion 120 into the threaded hole, since the length of the third threaded end portion 120 is small, it should be necessary to apply a greater external force to screw the third threaded end portion 120 into the threaded hole. However, when the spring 50 is driven by a larger external force to press the heat sink 30 downward against the chip 40, a larger instantaneous stress is easily generated, which causes a stress concentration at a corner of the chip 40, and not only the problem of corner damage of the chip 40 as shown in fig. 2 (a schematic diagram of corner damage of the chip) occurs; but also causes uneven force on the TIM1.5 material 60 during compression and expansion, which tends to cause an abnormal rise in temperature of the die 40.

In order to solve the above problem, the embodiment of the present application provides an installation structure of a PCB 20 and a heat sink 30, during an installation process, a second end of a screw structure 10 can be preferentially contacted with a threaded hole of the PCB 20, so that when a spring 50 placed in the screw structure 10 is compressed downward by a target pressure, the heat sink 30 can be pushed to press against a chip 40, a large instantaneous stress cannot be generated on the chip 40, further, damage conditions such as cracks and the like of the chip 40 due to uneven stress are avoided, and abnormal junction temperature of the chip 40 cannot occur.

Specifically, please refer to fig. 3, which is a schematic diagram of an installation structure of a PCB and a heat sink according to an embodiment of the present application. As shown in fig. 3, the mounting structure may include a PCB 20, a heat sink 30 and a chip 40, wherein a lower surface of the chip 40 is attached to the PCB 20, and an upper surface of the chip 40 is attached to a lower surface of the heat sink 30. In addition, the mounting structure further comprises a screw structure 10 and a spring 50, wherein the screw structure 10 is arranged through the heat sink 30, the spring 50 is sleeved on the screw structure 10, and a second end of the screw structure 10 is in threaded connection with a threaded hole of the PCB 20; the spring length of the spring 50 in its natural state is a first value;

when the spring 50 is subjected to the target pressure, the spring length of the spring 50 is adjusted from a first value to a second value to push the heat sink 30 against the die 40.

In this example, the screw structure 10 shown in fig. 3 may be a structure shown in a part a (specifically, refer to subsequent fig. 4 b-4 c), or may be a structure shown in a part b (specifically, refer to subsequent 12 in fig. 6), and is not limited herein. In addition, since the second end of the screw structure 10 in the mounting structure is screwed with the threaded hole of the PCB 20 during the mounting process, a bottom stressed supporting point is provided. Moreover, since the spring 50 is sleeved on the screw structure 10, the spring length of the spring 50 in the natural state is equal to the distance between the first end of the screw structure 10 and the upper surface of the heat sink 30. Therefore, if the spring 50 is subjected to a target pressure after the second end of the screw structure 10 has been screwed into the threaded hole of the PCB board 20, the spring 50 is slowly compressed from the first value to the second value at the target pressure, thereby pushing the heat sink 30 to press the chip 40. Since the second end of the screw structure 10 is screwed into the threaded hole of the PCB 20 to provide a bottom-stressed supporting point, the chip 40 is not stressed at an angle when the spring 50 pushes the heat sink 30 to press the chip 40. Thus, in the process of mounting the heat sink 30 and the chip 40 on the PCB 20, the chip 40 is prevented from being damaged by cracks due to uneven stress, and the chip 40 does not have abnormal junction temperature.

It should be noted that, in some examples, a heat conducting material, such as TIM1.5, may also be disposed between the heat spreader 30 and the chip 40, which is not limited herein.

Specifically, fig. 4a is a schematic view of another mounting structure provided in the embodiment of the present application. On the basis of fig. 3, the mounting structure shown in fig. 4a further comprises a nut 60, the screw structure 10 comprises a double male screw 11, the double male screw 11 may comprise a first threaded end 110, a second threaded end 111 and a first threaded polished rod 112 (see in particular fig. 4 b); the first threaded end 110 is in threaded connection with the threaded hole of the PCB 20, the distance between the second threaded end 111 and the lower surface of the heat sink 30 is a first value, and the spring 50 is sleeved on the first threaded polish rod 112;

the nut 60 is screwed into the second threaded end 111 to subject the spring 50 to the target pressure.

In this example, the double male screw 11 may include a first threaded end 110, a second threaded end 111, and a first threaded polished rod 112. The first thread end 110 is first in threaded connection with the threaded hole of the PCB 20, so as to achieve the fastening effect of the thread pair, and also can serve as a stress supporting point. Moreover, the spring 50 is sleeved on the first threaded polish rod 112. Then, when the spring 50 is in a natural state without receiving an external force, the nut 60 at this time just contacts the second thread end 111, and another thread pair is formed. Thus, when the nut 60 is screwed into the second threaded end 111, the spring 50 is subjected to the aforementioned target pressure, so that the spring length of the spring 50 is adjusted from the first value to the second value, i.e., the spring 50 obtains the target compression amount, thereby providing a pressure required for the heat sink 30 to press against the chip 40, and further pushing the heat sink 30 to press against the chip 40.

Optionally, in some examples, on the basis of the mounting structure described in fig. 4a, the nut 60 may be screwed into the second threaded end portion 111 according to a preset number of turns, so that the springs 50 can obtain the same target compression amount when being subjected to the same target pressure, and when pushing the heat sink 30 to press the chip 40, the chip 40 can be subjected to uniform pressure, and cracks and the like are avoided.

Optionally, in other examples, the above-described double male screw 11 depicted in fig. 4b further includes a stop surface 113 (specifically, refer to fig. 4c, which is a schematic view of another double male screw 11 provided in the present application). The stop surface 113 is used to set the distance between the nut 60 and the heat sink 30 to the second value when the nut 60 is screwed into the second threaded end 111 to the first threaded polish rod 112. As can be seen from fig. 4c, the second threaded end portion 111 is connected to the first threaded polish rod 112, when the nut 60 is screwed into the second threaded end portion 111 and contacts the first threaded polish rod 112, the distance between the nut 60 and the heat sink 30 can be the second value, that is, when the spring 50 can receive a fixed target pressure, a fixed target compression amount is obtained, so that when the heat sink 30 is pushed to press the chip 40, the chip 40 can receive a uniform pressure, and cracks and the like are avoided.

To facilitate understanding of the mounting structure depicted in fig. 4a, a description will be given below of a specifically used mounting process.

First, fig. 5a shows a schematic view of the dual male screws provided in the present application fastened to a PCB board. As can be seen from fig. 5a, the first threaded end 110 of the double male screw 11 is screwed into the threaded hole of the PCB board 20. The first threaded end 110 may be screwed into a threaded hole of the PCB 20 using an electric screwdriver or the like to form a screw pair for fastening.

Next, fig. 5b shows a schematic view of the heat sink provided by the present application being threaded through the double male screws. As can be seen from fig. 5b, after the first threaded end 110 is screwed into the threaded hole of the PCB 20, the heat sink 30 is further inserted into the first threaded polish rod 112, so that the heat sink 30 contacts the chip 40 attached to the PCB 20. Thus, the heat sink 30 can be assembled to the PCB board 20.

Furthermore, fig. 5c shows a schematic diagram of the spring sleeve provided by the present application being disposed on the dual male screw. As shown in fig. 5c, after the heat sink 30 is inserted into the first threaded rod 112, the spring 50 can be sleeved on the first threaded rod 112. Specifically, the spring 50 is sleeved on the outer surface of the first threaded polish rod 112.

Finally, fig. 5d shows a schematic view of the screwing of a nut into a double male screw as provided by the present application. As can be seen from fig. 5d, after the spring 50 is sleeved on the outer surface of the first threaded polish rod 112, the nut 60 is further screwed into the second threaded end portion 111. Thus, when the nut 60 is continuously screwed into the second screw end portion 111, an external force can be applied to the spring 50. Then, when the spring 50 is subjected to the target pressure, the spring 50 can obtain the target compression amount, i.e., the spring length of the spring 50 is adjusted from the first value to the second value, so as to push the heat sink 30 to press the chip 40.

It should be noted that, while fig. 5 a-5 d only describe the mounting process from the perspective of one dual male screw 11, in practical applications, if a plurality of threaded holes are provided on the PCB 20, the mounting process of the heat sink 30 and the chip 40 on the PCB 20 by each dual male screw 11 can be understood according to the process of fig. 5 a-5 d. It should also be noted that each nut 60 should be threaded into the second threaded end 111 in turn on a diagonal basis with the same preset number of turns so that the spring 50 is uniformly stressed. For example, as for the nuts 601 to 604 in fig. 5d, the

nuts

601, 602, 603, and 604 can be screwed into the second threaded ends 111 in the order of the

nuts

601, 602, 603, and 604, and the specific screwing order is only required to follow the diagonal principle, and is not limited herein.

Alternatively, in other examples, fig. 6 may also be referred to, which is a schematic diagram of another mounting structure provided in the embodiment of the present application. On the basis of fig. 3, the screw structure 10 shown in fig. 6 comprises a spring screw 12, the spring screw 12 comprising a third threaded end 120 and a second threaded polish rod 121. Wherein, the spring 50 is sleeved on the second threaded polish rod 121, and the second threaded polish rod 121 is connected with the third threaded end 120;

when the spring 50 is subjected to the target pressure, the second threaded polish rod 121 with the length meeting the first preset range drives the third threaded end 120 to be screwed into the threaded hole of the PCB 20; alternatively, the first and second electrodes may be,

when the spring 50 is subjected to the target pressure, the third threaded end 120 having a length satisfying the second preset range is screwed into the threaded hole of the PCB board 20.

That is, it is understood that the length of the third threaded end 120 is small due to the prior structure shown in fig. 1. Accordingly, in the present application, the length of the second threaded polish rod 121 can be extended as appropriate, and can be understood with reference to parts a and b of fig. 7, wherein a represents the length of the existing second threaded polish rod 121 and b represents the length of the second threaded polish rod 121 of the present application. It is appreciated that the extended length of the second threaded polish rod 121 satisfies a first predetermined range, which is not specifically limited herein.

Alternatively, in the present application, the length of the third threaded end 120 can also be extended as appropriate, and can be understood by referring to the portions a and c in fig. 7, where a shows the length of the existing third threaded end 120, and c shows the length of the third threaded end 120 in the present application. It is appreciated that the extended length of the third threaded end 120 satisfies a second predetermined range. Illustratively, the second predetermined range satisfies 0 to 10 mm, and is not limited herein.

Moreover, since the spring 50 is sleeved on the second threaded polish rod 121, when the head of the screw of the spring 50 is continuously pressed, the second threaded polish rod 121 is continuously stressed to move, so that the spring 50 is subjected to the target pressure. At this time, since the second threaded polish rod 121 is connected to the third threaded end portion 120, when the spring 50 is subjected to the target pressure, the second threaded polish rod 121 with the length satisfying the first preset range will drive the third threaded end portion 120 to be preferentially screwed into the threaded hole of the PCB 20; alternatively, the third threaded end 120 with a length satisfying the second predetermined range is also preferably screwed into the threaded hole of the PCB 20, so as to provide a fastening force for the subsequent process of pressing the heat sink 30 against the chip 40.

Thus, if the spring 50 is subjected to a target pressure, at which the spring 50 is slowly compressed from the first value to the second value, after the third threaded end 120 of the screw of the spring 50 has been preferentially threaded with the threaded hole of the PCB board 20, the corresponding spring length is pushed against the chip 40. Furthermore, since the threaded connection of the third threaded end 120 with the threaded hole of the PCB 20 can serve as a bottom-stressed support point, the chip 40 is not stressed at an angle when the spring 50 pushes the heat sink 30 to press the chip 40. Thus, in the process of mounting the heat sink 30 and the chip 40 on the PCB 20, the chip 40 is prevented from being damaged by cracks due to uneven stress, and the chip 40 does not have abnormal junction temperature.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. The utility model provides a mounting structure of PCB board and radiator, mounting structure includes the PCB board radiator, chip, the lower surface subsides of chip are located the PCB board, the upper surface subsides of chip are located the lower surface of radiator, its characterized in that, mounting structure still includes: screw structures, springs;

the screw structure penetrates through the radiator, the spring is sleeved on the screw structure, the length of the spring in a natural state is a first value, and a second end of the screw structure is in threaded connection with a threaded hole of the PCB;

when the spring is subjected to the target pressure, the spring length of the spring is adjusted from the first value to a second value so as to push the heat sink to press the chip.

2. The mounting structure of claim 1, wherein the mounting structure further comprises a nut, the screw structure comprises a double male screw, the double male screw comprises a first threaded end, a second threaded end and a first threaded polished rod, the first threaded end is in threaded connection with the threaded hole of the PCB board, the distance between the second threaded end and the lower surface of the heat sink is the first value, and the spring is sleeved on the first threaded polished rod;

threading the nut into the second threaded end to subject the spring to the target pressure.

3. The mounting structure of claim 2, wherein the nut is threaded into the second threaded end a predetermined number of turns.

4. The mounting structure of claim 2 or 3, wherein the double male screw further comprises a stop surface for setting a distance between the nut and the heat sink to the second value when the nut is threaded into the second threaded end to the first threaded polish rod.

5. The mounting structure of claim 1, wherein the screw structure comprises a spring screw including a third threaded end and a second threaded rod, the spring sleeve being disposed on the second threaded rod, the second threaded rod being connected to the second threaded end;

when the spring is subjected to the target pressure, the second threaded polish rod with the length meeting a first preset range drives the third threaded end part to be screwed into the threaded hole of the PCB; or the like, or, alternatively,

and when the spring is subjected to the target pressure, the third threaded end part with the length meeting a second preset range is screwed into the threaded hole of the PCB.

6. The mounting structure according to any one of claims 1 to 3, wherein a thermally conductive material is provided between the heat sink and the chip.

7. The mounting structure according to claim 4, wherein a thermally conductive material is provided between the heat sink and the chip.

8. The mounting structure according to claim 5, wherein a thermally conductive material is provided between the heat sink and the chip.