CN113727523B

CN113727523B - Semiconductor device fixing structure

Info

Publication number: CN113727523B
Application number: CN202110993116.XA
Authority: CN
Inventors: 吕广贤; 陶鹤英; 徐�明; 孙巨禄
Original assignee: Powerland Technology Inc
Current assignee: Powerland Technology Inc
Priority date: 2021-08-27
Filing date: 2021-08-27
Publication date: 2023-01-24
Anticipated expiration: 2041-08-27
Also published as: CN113727523A

Abstract

The present invention provides a semiconductor device fixing structure, including: a substrate; a heat dissipation plate disposed on the substrate; the mainboard is arranged on the heat dissipation plate, extends towards the outer side of the heat dissipation plate, and is provided with a semiconductor device; the insulating gasket is arranged on the heat dissipation plate and covers the semiconductor device; the first part of the metal elastic sheet is arranged on the insulating gasket and used for extruding the insulating gasket, the second part of the metal elastic sheet is fixed on the heat dissipation plate or the substrate, and the first part and the second part are arranged at an angle. The semiconductor device fixing structure provided by the invention has a simple structure.

Description

Semiconductor device fixing structure

Technical Field

The invention relates to the technical field of electronics, in particular to a semiconductor device fixing structure.

Background

In a power layout of a switching power supply, a semiconductor device is a core power device, which often bears most of circuit loss and is expressed in the form of heat. High junction temperatures have a large impact on the operating efficiency and lifetime of semiconductor devices. Therefore, a heat sink is generally required to dissipate heat from the semiconductor device.

In the case of package-on-package heat dissipation, especially the primary side, the electrical distance between the semiconductor device and the surrounding metal devices or structures needs to be handled to meet safety code requirements. A metal pressing strip is generally used to cover a heat-shrinkable sleeve, and screws are used to fix and press the semiconductor device to realize reliable heat dissipation. Such assembly is difficult, thereby increasing the size of the overall layout space

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a semiconductor device fixing structure, which is convenient to assemble, simple in structure, and small in space size.

To achieve the above and other objects, the present invention provides a semiconductor device mounting structure, comprising:

a substrate;

a heat dissipation plate disposed on the substrate;

the mainboard is arranged on the heat dissipation plate, extends towards the outer side of the heat dissipation plate, and is provided with a semiconductor device;

the insulating gasket is arranged on the heat dissipation plate and covers the semiconductor device;

the first part of the metal elastic sheet is arranged on the insulating gasket and used for extruding the insulating gasket, the second part of the metal elastic sheet is fixed on the heat dissipation plate or the substrate, and the first part and the second part are arranged at an angle.

Furthermore, both ends of the heat dissipation plate are fixed on the substrate through screws.

Further, the main board includes a first area and a second area, and the first area is connected to the second area.

Further, the width of the first region is smaller than the width of the second region.

Further, the heat dissipation plate includes a middle recess portion, the first region is fixed to the middle recess portion by a screw, and the second region is located outside the middle recess portion.

Further, the semiconductor device is fixed on the main board through pins.

Further, the insulating pad includes an upper pad and a lower pad, and the semiconductor device is located between the upper pad and the lower pad.

Further, the upper pad is in contact with the first portion, and the lower pad is in contact with the heat dissipation plate.

Further, the second portion is fixed to a side wall of the heat dissipation plate by screws.

Further, the second portion is fixed on a vertical portion of the substrate by a screw, and the height of the vertical portion is greater than that of the heat dissipation plate.

Further, the main board further comprises a capacitor, and the capacitor is arranged on the second area.

Further, the main board includes a PCB circuit board.

Further, the angle of the first and second portions comprises 90 °.

In summary, the present invention provides a semiconductor device fixing structure, after a capacitor and a semiconductor device are soldered on a motherboard, the capacitor and the semiconductor device are fixed on a heat dissipation plate through an intermediate screw, so as to achieve reliable grounding of the capacitor. Then, the semiconductor device is wrapped up through the insulating gasket, the metal elastic sheet is laterally locked on the heat dissipation plate from the horizontal direction through the countersunk head screw, in the screw locking process, because the metal elastic sheet has a specific bending angle, the horizontal locking force is converted into vertical pressure, and the semiconductor device is tightly pressed on the insulating gasket, so that the heat dissipation purpose is achieved; and finally, the whole assembly is locked on the substrate or the shell through screws with gaskets. The structure occupies small space and is reliable in connection. The structure can be used as a standard universal assembly and is used in various occasions, such as assembly of a shell in the form of a section bar, a die casting and the like. The structure reduces the grounding routing path of the capacitor as much as possible, and has good EMI noise performance. The structure can well meet the isolation requirement of the electric creepage distance.

Drawings

FIG. 1: the structure of the semiconductor device mounting structure in one embodiment of the present invention.

FIG. 2: the exploded view of fig. 1 in one embodiment of the invention.

FIG. 3: a structure diagram of a semiconductor device fixing structure in an embodiment of the present invention.

FIG. 4 is a schematic view of: the exploded view of fig. 3 in one embodiment of the present invention.

FIG. 5 is a schematic view of: the structure of the semiconductor device mounting structure in one embodiment of the present invention.

FIG. 6: the exploded view of fig. 5 in one embodiment of the present invention.

FIG. 7 is a schematic view of: a structure diagram of a semiconductor device fixing structure in an embodiment of the present invention.

FIG. 8: the exploded view of fig. 7 in one embodiment of the present invention.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

As shown in fig. 1, the present embodiment proposes a semiconductor device mounting structure 100, and the semiconductor device mounting structure 100 may include a substrate 101, a heat dissipation plate 102, a main board 103, a capacitor 104, a semiconductor device 105, an insulating spacer 106, and a metal elastic sheet 107.

As shown in fig. 2, fig. 2 is shown as an exploded view of fig. 1. The heat dissipation plate 102 is disposed on the substrate 101, and the substrate 101 may have a square structure, for example, a rectangular parallelepiped structure. Heat sink plate 102 is fixed to substrate 101 by fastening screws 108, and fastening screws 108 are provided on both sides of heat sink plate 102, for example. As can be seen from fig. 2, screw holes are respectively provided at both sides of the heat radiating plate 102, and also screw holes (not shown in fig. 2) are provided on the substrate 101 directly below the screw holes, so that the heat radiating plate 102 can be fixed on the substrate 101 by placing fastening screws 108 in the screw holes. The fastening screw 108 is, for example, a screw with a washer.

As shown in fig. 2, in the present embodiment, the heat dissipation plate 102 may be a heat dissipation boss, that is, the heat dissipation plate 102 includes a middle concave portion 1021, and convex portions are formed on both sides of the middle concave portion 1021, and the heat dissipation plate 102 can dissipate heat of the semiconductor device 105. In the present embodiment, the main board 103 is disposed on the heat dissipation plate 102, and the heat dissipation plate 103 may include the first region 1031 and the second region 1032. The first region 1031 and the second region 1032 are connected, and the first region 1031 and the second region 1032 are in the same plane. The width of the first zone 1031 is smaller than that of the second zone 1032, and thus the first zone 1031 may be fixed on the intermediate concave portion 1021, whereby the second zone 1032 may be located outside the heat dissipation plate 102. The width of the first area 1031 may be equal to or less than the width of the intermediate recess 1021, and the first area 1031 is fixed to the intermediate recess 1021 by, for example, an intermediate screw 109. The second region 1032 may be in contact with a sidewall of the heat dissipation plate 102, thereby forming a stable structure. And the size of the semiconductor device fixing structure can be reduced due to the presence of the intermediate concave portion 1021. In this embodiment, a capacitor 104 and a semiconductor device 105 are also provided on the second region 1032. The capacitor 104 and the semiconductor device 105 are soldered to the main board 103 by, for example, pins. In this embodiment, the capacitor 104, the semiconductor device 105, and the main board 103 may be collectively referred to as a PCBA. The main board 103 may be a PCB circuit board, the capacitor 104 may be a Y capacitor, and the semiconductor device 105 may be a MOSFET. In the present embodiment, for example, two semiconductor devices 105 are provided on the second region 1032, but it is needless to say that more semiconductor devices 105 may be provided.

As shown in fig. 1-2, in the present embodiment, the semiconductor device 105 is located inside the insulating spacer 106, i.e. the semiconductor device 105 is completely surrounded by the insulating spacer 106. The insulating gasket 106 may include an upper gasket 1061 and a lower gasket 1062. The upper pad 1061 and the lower pad 1062 are coupled. The upper pad 1061 and the lower pad 1062 are formed in an open shape, whereby the semiconductor device 105 can be disposed in the insulating pad 106 through the open shape. The upper pad 1061 may contact the top surface of the semiconductor device 105, and the lower pad 1062 may contact the bottom surface of the semiconductor device 105. The insulating spacer 106 also has a good heat dissipation effect, and thus can quickly transfer heat of the semiconductor device 105.

As shown in fig. 2, in the present embodiment, a metal elastic sheet 107 is further disposed on the insulating spacer 106, and the metal elastic sheet 107 may include a first portion 1071 and a second portion 1072. The first portion 1071 and the second portion 1072 are angularly disposed. The first portion 1071 is formed on the upper pad 1061, the second portion 1072 contacts the side wall of the heat sink 102, the second portion 1072 is formed with screw holes, and the side wall of the heat sink 102 is formed with screw holes, so that the second portion 1072 can be fixed to the heat sink 102 when the countersunk screws 110 are received in the screw holes, thereby fixing the metal elastic piece 107 to the heat sink 102. The first portion 1071 and the second portion 1072 may be said to be chamfered and connected, the angle between the first portion 1071 and the second portion 1072 being, for example, 90 °. In this embodiment, the metal elastic sheet 107 is laterally locked to the heat dissipation plate 102 by the countersunk screws 108 from the horizontal direction, and in the process of locking the screws, since the metal elastic sheet 107 has a specific bending angle, the horizontal locking force is converted into a vertical pressure, and the semiconductor device 105 is tightly pressed on the insulating gasket 106, thereby achieving the purpose of heat dissipation.

As shown in fig. 1 and fig. 3-4, the present embodiment also proposes another semiconductor device mounting structure 100, and fig. 4 is shown as an exploded view of fig. 3. In the difference between fig. 1 and 3, the substrate 101 in fig. 3 includes a horizontal portion 1011 and a vertical portion 1012. The horizontal portion 1011 is perpendicular to the vertical portion 1012. The heat dissipation plate 102 is disposed on the horizontal portion 1011 and the side wall of the heat dissipation plate 102 abuts on the vertical portion 1012, the height of the vertical portion 1012 being greater than the height of the heat dissipation plate 102. Meanwhile, the first portion 1071 is in contact with the insulating gasket 106, the second portion 1072 is in contact with the vertical portion 1012, screw holes are formed in the vertical portion 1012 and the second portion 1072, and when the countersunk screws 110 are arranged in the screw holes, the metal elastic sheet 107 can be fixed on the substrate 101, and meanwhile, in the screw locking process, due to the fact that the metal elastic sheet 107 has a specific bending angle, horizontal locking force is converted into vertical pressure, the semiconductor device 105 is tightly pressed on the insulating gasket 106, and therefore the heat dissipation purpose is achieved.

As shown in fig. 5-6, fig. 5 shows another semiconductor device mounting structure 100, and fig. 6 shows an exploded view of fig. 5. The semiconductor device mounting structure 100 may include a heat dissipation plate 102, the heat dissipation plate 102 may include an intermediate concave portion 1021, and the first region of the main board 103 may be disposed on the intermediate concave portion 1021. Two semiconductor devices 105 are disposed on the main board 103, the two semiconductor devices 105 are respectively disposed in two insulating pads 106, and the insulating pads 106 completely cover the semiconductor devices 105. The structure of the insulating spacer 106 can refer to the above description. The insulating spacer 106 is further provided with a metal elastic piece 107, and the metal elastic piece 107 is in contact with the upper spacer of the insulating spacer 106. The metal elastic piece 107 is provided with a screw hole, and when a fastening screw is disposed in the screw hole, the metal elastic piece 107 can be fixed on the insulating spacer 106, and the main board 103 can be fixed on the central recess 1021.

As shown in fig. 7-8, the present embodiment further proposes another semiconductor device mounting structure 100, and fig. 8 is an exploded view of fig. 7. The semiconductor device fixing structure 100 may include a substrate 101, and the structure of the substrate 101 may refer to that of the substrate 101 in fig. 4. A heat sink 102 is disposed on the horizontal portion of the substrate 101, and the heat sink 102 may have a square structure. An upper pad 1062, a semiconductor device 104, and an upper pad 1061 are provided on the heat sink 102. The semiconductor device 104 is positioned between the upper pad 1061 and the lower pad 1062, that is, the top surface and the bottom surface of the semiconductor device 104 are in contact with the upper pad 1061 and the lower pad 1062, respectively. The upper gasket 1061 is provided with a metal elastic piece 107, the metal elastic piece 107 is provided with a fixing block 111, and the fixing block 111 is provided with a screw hole penetrating through the fixing block 111. A fastening screw 108 may be disposed in the fixing block 111, and the fastening screw 108 may pass through a screw hole to be in contact with the metal elastic sheet 107, and when the fastening screw 108 is rotated downward, so that the metal elastic sheet 107 may be pressed, the metal elastic sheet 107 presses the upper pad 1061, so that the semiconductor device 104 may be fixed between the upper pad 1061 and the lower pad 1062. On the sidewall of the fixing block 111, a vertical portion of the substrate 101 is also provided with a screw hole, and when a countersunk screw 110 is passed through the screw hole on the vertical portion, the screw hole on the sidewall of the fixing block 111, the fixing block 111 can be fixed on the substrate 101.

In summary, the present invention provides a semiconductor device fixing structure, after a capacitor and a semiconductor device are soldered on a motherboard, the capacitor and the semiconductor device are fixed on a heat dissipation plate through an intermediate screw, so as to achieve reliable grounding of the capacitor. Then, the semiconductor device is wrapped up through the insulating gasket, the metal elastic sheet is laterally locked on the heat dissipation plate from the horizontal direction through the countersunk head screw, in the screw locking process, because the metal elastic sheet has a specific bending angle, the horizontal locking force is converted into vertical pressure, and the semiconductor device is tightly pressed on the insulating gasket, so that the heat dissipation purpose is achieved; and finally, the whole assembly is locked on the substrate or the shell through the screws with the gaskets. The structure occupies small space and is reliable in connection. The structure can be used as a standard universal assembly, and is used in various occasions, such as the assembly of shells in the forms of section bars, die castings and the like. The structure reduces the grounding routing path of the capacitor as much as possible, and has good EMI noise performance. The structure can well meet the isolation requirement of the electric creepage distance.

The above description is only a preferred embodiment of the present application and a description of the applied technical principle, and it should be understood by those skilled in the art that the scope of the present invention related to the present application is not limited to the technical solution of the specific combination of the above technical features, and also covers other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept, for example, the technical solutions formed by mutually replacing the above features with (but not limited to) technical features having similar functions disclosed in the present application.

Other technical features than those described in the specification are known to those skilled in the art, and are not described herein in detail in order to highlight the innovative features of the present invention.

Claims

1. A semiconductor device mounting structure, comprising:

a substrate;

a heat dissipation plate disposed on the substrate, the heat dissipation plate including a middle recess;

a main board disposed on the heat dissipation plate, the main board including a first region and a second region, the first region being connected to the second region, a width of the first region being smaller than a width of the second region, the first region being fixed to the intermediate recessed portion, the second region being located outside the intermediate recessed portion, the main board being provided with a semiconductor device;

2. The semiconductor device fixing structure according to claim 1, wherein both ends of the heat radiating plate are fixed to the substrate by screws.

3. The semiconductor device fixing structure according to claim 1, wherein the first region is fixed to the intermediate recessed portion by a screw.

4. The semiconductor device fixing structure according to claim 1, wherein the semiconductor device is fixed to the main board by a pin.

5. The semiconductor device mounting structure according to claim 1, wherein the insulating spacer includes an upper spacer and a lower spacer, and the semiconductor device is located between the upper spacer and the lower spacer.

6. The semiconductor device fixing structure according to claim 5, wherein the upper pad is in contact with the first portion, and the lower pad is in contact with the heat dissipation plate.

7. The semiconductor device fixing structure according to claim 1, wherein the second portion is fixed to a side wall of the heat dissipation plate by a screw.

8. The semiconductor device fixing structure according to claim 1, wherein the second portion is fixed to a vertical portion of the substrate by a screw, the vertical portion having a height larger than that of the heat dissipation plate.

9. The semiconductor device mounting structure according to claim 1, further comprising a capacitor on the main board, the capacitor being provided on the second region.

10. The semiconductor device fixing structure according to claim 1, wherein the main board comprises a PCB circuit board.

11. The semiconductor device mounting structure of claim 1 wherein the angle of the first and second portions comprises 90 °.