Heat dissipation assembly of power device

Abstract

The utility model discloses a heat radiation assembly of a power device, comprising a PCB, the surface of the PCB is fixedly provided with an enclosure frame, the interior of the enclosure frame is provided with a patch power device, the metal heat radiation surface of the patch power device is connected with a bonding pad of the PCB in an SMT patch welding mode, and the metal heat radiation surface of the patch power device is connected with the bonding pad of the PCB. The SMD power device forms a space with five closed surfaces in the PCB and the enclosed frame, and the space with five closed surfaces formed in the PCB and the enclosed frame is filled with an insulating heat-conducting colloid. According to the utility model, the five plastic sealing surfaces of the power device, the PCB bonding pads at the periphery of the metal heat dissipation surface and the wiring copper foil are wrapped by the insulating heat-conducting colloid, all space outer surfaces of the power device are fully utilized, and compared with the existing assembly and heat dissipation mode, the novel mode has the advantages of equivalent total heat dissipation capability, simple structure, simple process and low manufacturing cost.

Description

Technical Field

[0001] The utility model relates to the technical field of heat dissipation of power devices, and more specifically to a heat dissipation component for power devices. Background Art

[0002] Power devices are electronic components with relatively large output power. Electronic components in the output stage power amplifier of a large audio system belong to power devices, and the IGBT in an induction cooker is also one. Power devices include: high-power transistors, thyristors, bidirectional thyristors, GTOs, MOSFETs, and IGBTs, etc. IGBT (Insulated Gate Bipolar Transistor), an insulated gate bipolar transistor, is a composite fully controlled voltage-driven power semiconductor device composed of a BJT (bipolar junction transistor) and a MOS (insulated gate field effect transistor), and has the advantages of both the high input impedance of the MOSFET and the low conduction voltage drop of the GTR. The GTR has a low saturation voltage drop and a large carrier density, but a large drive current; the MOSFET has a very small drive power and a fast switching speed, but a large conduction voltage drop and a small carrier density. The IGBT combines the advantages of the above two devices, with a small drive power and a low saturation voltage drop. It is very suitable for application in variable current systems with a DC voltage of 600V or above, such as AC motors, frequency converters, switching power supplies, lighting circuits, traction drives, and other fields.

[0003] During the switching control process of power devices, a certain proportion of energy loss will be generated due to the existence of conduction voltage drop and switching linear voltage division loss. The loss is generated in the form of heat from the internal wafers and connecting wires of the power devices, and is conducted to the external contact medium through two paths: the heat dissipation metal surface and the outer surface of the plastic package in the power device package.

[0004] At present, the existing heat dissipation methods for power devices have a single heat transfer path, and their effective heat dissipation area is only one-third of the outer surface area of the power device, and the structure is complex, the process is complex, and the manufacturing cost is high. Therefore, a new technical solution is needed to solve this problem. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a heat dissipation component and a heat dissipation method for power devices, which solve the problems that the existing heat dissipation method for power devices has a single heat transfer path, the effective heat dissipation area is only one-third of the outer surface area of the power device, and the structure is complex, the process is complex, and the manufacturing cost is high.

[0006] To achieve the above object, the present utility model provides the following technical solutions: A heat dissipation component and a heat dissipation method for a power device, including: a PCB board, on the surface of which an enclosing frame is fixedly installed. The enclosing frame is arranged in a rectangular structure, and a surface-mounted power device is arranged inside the enclosing frame. An insulating and heat-conducting colloid is filled in the PCB board and the enclosing frame, and an external heat sink is arranged outside the whole formed by the PCB board, the surface-mounted power device and the insulating and heat-conducting colloid.

[0007] As a preferred embodiment of the present utility model, the height of the insulating and heat-conducting colloid is greater than or equal to the height of the enclosing frame.

[0008] As a preferred embodiment of the present utility model, the surface-mounted power device forms a five-sided enclosed space within the PCB board and the enclosing frame.

[0009] As a preferred embodiment of the present utility model, the metal heat dissipation surface of the surface-mounted power device is connected to the solder pad of the PCB board by SMT patch welding.

[0010] Step 1: Connect the metal heat dissipation surface of the surface-mounted power device to the solder pad of the PCB board by SMT patch welding to form an integral body.

[0011] Step 2: Connect the enclosing frame to the PCB board so that the surface-mounted power device forms a five-sided enclosed space within the PCB board and the enclosing frame.

[0012] Step 3: Fill the insulating and heat-conducting colloid into the space formed by the PCB board and the enclosing frame so that the height of the colloid is greater than or equal to the height of the enclosing frame.

[0013] Step 4: Connect the whole formed by the PCB board, the power device and the insulating and heat-conducting colloid to the external heat sink by an external force to complete the connection process of the whole power device assembly and heat dissipation.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] The heat dissipation component of the present utility model includes an enclosing frame fixedly installed on the PCB board. A surface-mounted power device is arranged inside the enclosing frame. The metal heat dissipation surface of the power device is connected to the solder pads of the PCB board by SMT soldering, so that the power device forms a five-sided enclosed space within the PCB board and the enclosing frame. An insulating and heat-conducting colloid is filled into the space formed by the PCB board and the enclosing frame, and the height of the colloid is greater than or equal to the height of the enclosing frame. The whole formed by the PCB board, the surface-mounted power device and the insulating and heat-conducting colloid is connected to an external heat sink by an external force to complete the connection process of the entire power device assembly and heat dissipation. The five plastic covers of the power device and the PCB solder pads and connecting copper foils around the metal heat dissipation surface are wrapped by the insulating and heat-conducting colloid, making full use of all the outer surfaces of the space of the power device. The heat generated by the wafer inside the surface-mounted power device is conducted to the final heat dissipation purpose through two paths: the bottom heat-conducting metal, the solder pads, the copper foil, the insulating and heat-conducting colloid, and the plastic package shell and the insulating and heat-conducting colloid. Compared with the existing assembly and heat dissipation methods, the total heat dissipation capacity of the new method is equivalent, and it has the advantages of simple structure, simple process and low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the surface structure of the PCB board of the present utility model;

[0017] Figure 2 It is a schematic diagram of the overall structure of the present utility model.

[0018] In the figure: 1, PCB board; 2, enclosing frame; 3, surface-mounted power device; 4, insulating and heat-conducting colloid; 5, external heat sink. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0020] Please refer to Figure 1-2, the present utility model provides a technical solution: a heat dissipation component and a heat dissipation method for a power device, including: a PCB board 1, on the surface of the PCB board 1, an enclosing frame 2 is fixedly installed. The enclosing frame 2 is arranged in a rectangular structure, and a surface-mounted power device 3 is arranged inside the enclosing frame 2. An insulating heat-conducting colloid 4 is filled in the PCB board 1 and the enclosing frame 2. An external heat sink 5 is arranged outside the whole formed by the PCB board 1, the surface-mounted power device 3 and the insulating heat-conducting colloid 4. The heat dissipation component includes the enclosing frame 2 fixedly installed with the PCB board 1, and the surface-mounted power device 3 is arranged inside the enclosing frame 2. The metal heat dissipation surface of the power device is connected to the pad of the PCB board 1 by means of SMT patch welding, so that the power device forms a space enclosed on five sides within the PCB board 1 and the enclosing frame 2. The insulating heat-conducting colloid 4 is filled into the space formed by the PCB board 1 and the enclosing frame 2, so that the height of the colloid is greater than or equal to the height of the enclosing frame 2. The whole formed by the PCB board 1, the surface-mounted power device 3 and the insulating heat-conducting colloid 4 is connected to the external heat sink 5 by an external force, completing the connection process of the whole power device assembly and heat dissipation. The insulating heat-conducting colloid 4 is used to wrap the five plastic covers of the power device and the PCB pads and connecting copper foils around the metal heat dissipation surface, making full use of all the outer surfaces of the space of the power device. The heat generated by the wafer in the surface-mounted power device 3 is conducted to the final heat dissipation purpose through two paths: the bottom heat-conducting metal, the pad, the copper foil and the insulating heat-conducting colloid 4, and the plastic package shell and the insulating heat-conducting colloid 4. Compared with the existing assembly and heat dissipation methods, the total heat dissipation capacity of the new method is equivalent, and the structure is simple, the process is simple and the manufacturing cost is low.

[0021] Further improved, as Figure 1 shown: the height of the insulating heat-conducting colloid 4 is greater than or equal to the height of the enclosing frame 2, and this setting facilitates the connection with the external heat sink.

[0022] Further improved, as Figure 1 shown: the surface-mounted power device 3 forms a space enclosed on five sides within the PCB board 1 and the enclosing frame 2, and the formed enclosed space facilitates the filling of the insulating heat-dissipating colloid so that it will not overflow.

[0023] Further improved, as Figure 1 shown: the metal heat dissipation surface of the surface-mounted power device 3 is connected to the pad of the PCB board 1 by means of SMT patch welding, and this setting ensures the stability of the installation.

[0024] Further improved, the heat dissipation method of the power device includes the following steps:

[0025] Step 1: Connect the metal heat dissipation surface of the surface-mounted power device 3 to the pad of the PCB board 1 by means of SMT patch welding to become an integral body;

[0026] Step 2: Connect the enclosure frame 2 and the PCB board 1 together so that the surface-mounted power device 3 forms a space enclosed on five sides within the PCB board 1 and the enclosure frame 2;

[0027] Step 3: Fill the space formed by the PCB board 1 and the enclosure frame 2 with the insulating and thermally conductive colloid 4 so that the height of the colloid is greater than or equal to the height of the enclosure frame 2;

[0028] Step 4: Connect the whole formed by the PCB board 1, the power device and the insulating and thermally conductive colloid 4 to an external heat sink 5 by an external force to complete the connection process of the whole power device assembly and heat dissipation.

[0029] Working principle: The heat dissipation assembly includes an enclosure frame 2 fixedly installed on the PCB board 1. Inside the enclosure frame 2, there is a surface-mounted power device 3. The metal heat dissipation surface of the power device is connected to the solder pads of the PCB board 1 by SMT soldering, so that the power device forms a space enclosed on five sides within the PCB board 1 and the enclosure frame 2. Fill the space formed by the PCB board 1 and the enclosure frame 2 with the insulating and thermally conductive colloid 4 so that the height of the colloid is greater than or equal to the height of the enclosure frame 2. Connect the whole formed by the PCB board 1, the surface-mounted power device 3 and the insulating and thermally conductive colloid 4 to an external heat sink 5 by an external force to complete the connection process of the whole power device assembly and heat dissipation. Use the insulating and thermally conductive colloid 4 to wrap the five plastic covers of the power device and the PCB solder pads and connecting copper foils around the metal heat dissipation surface, making full use of all the outer surfaces of the space of the power device. The heat generated by the wafer inside the surface-mounted power device 3 is conducted to the final heat dissipation purpose through two paths: the bottom heat-conducting metal, the solder pads, the copper foil and the insulating and thermally conductive colloid 4, and the plastic package shell and the insulating and thermally conductive colloid 4. Compared with the existing assembly and heat dissipation methods, the total heat dissipation capacity of the new method is equivalent, with a simple structure, a simple technological process and a low manufacturing cost.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be encompassed within the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0031] The following points should be noted: First, in the description of this application, it should be noted that unless otherwise specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense, which can be a mechanical connection or an electrical connection, or the communication inside two components, and can be directly connected. The terms "upper", "lower", "left", "right", etc. are only used to represent the relative position relationship. When the absolute position of the object being described changes, the relative position relationship may change.

[0032] Finally, it should be noted that the above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A heat dissipation component of a power device, characterized in that: Including: A PCB board (1), on the surface of which an enclosing frame (2) is fixedly installed. The enclosing frame (2) is arranged in a rectangular structure, and a surface-mounted power device (3) is arranged inside the enclosing frame (2). An insulating and heat-conducting colloid (4) is filled in the PCB board (1) and the enclosing frame (2). An external heat sink (5) is arranged outside the whole formed by the PCB board (1), the surface-mounted power device (3) and the insulating and heat-conducting colloid (4).

2. The heat dissipation component of a power device according to claim 1, wherein: The height of the insulating and heat-conducting colloid (4) is greater than or equal to the height of the enclosing frame (2).

3. The heat dissipation component of a power device according to claim 1, characterized in that: The surface-mounted power device (3) forms a space with five closed surfaces inside the PCB board (1) and the enclosing frame (2).

4. The heat dissipation component of a power device according to claim 1, characterized in that: The metal heat dissipation surface of the surface-mounted power device (3) is connected to the pad of the PCB board (1) by means of SMT patch welding.

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