CN108055812B

CN108055812B - Heat radiation system of board-mounted power device

Info

Publication number: CN108055812B
Application number: CN201711438827.0A
Authority: CN
Inventors: 周萌; 王晓波; 胡锦; 姜宇
Original assignee: Shaanxi Aero Electric Co Ltd
Current assignee: Shaanxi Aero Electric Co Ltd
Priority date: 2017-12-27
Filing date: 2017-12-27
Publication date: 2019-12-17
Anticipated expiration: 2037-12-27
Also published as: CN108055812A

Abstract

The invention provides a heat dissipation system of a board-mounted power device, which comprises a radiator, a cold plate, a shell and a fan, wherein the cold plate is arranged on the shell; the bottom of the power device is additionally provided with a heat conduction insulating gasket, the power device is arranged on a PCB (printed Circuit Board) through a cold plate, and the cold plate is connected with the shell during installation to form a heat conduction mode for heat dissipation; the PCB printed board is a single-sided bonding pad, so that the short circuit phenomenon between a cold plate and the bonding pad is prevented; a radiator is additionally arranged on the top of the power device to form heat radiation; the fan provides the forced air supply perpendicular to PCB printed board installation direction, forms the heat dissipation of thermal convection mode. The invention adopts a method of combining conduction, convection and radiation to realize good heat dissipation of the onboard power device, so that the system has the advantages of good heat dissipation, high working efficiency, high reliability, long service life and the like.

Description

heat radiation system of board-mounted power device

Technical Field

The invention belongs to the technical field of component heat dissipation, and relates to a heat dissipation system of an onboard power device.

Background

At present, along with the increase of power devices, the contradiction between power and heat dissipation increasingly becomes an important technical problem for assembling power electronic components. Generally, a significant portion of the electrical energy consumed by a power device during operation is converted to heat. In order to keep the operating temperature of the power device within a reasonable range, the operating environment temperature of the power device must be kept within the reasonable range, and the power device must be subjected to heat dissipation treatment. In a heat dissipation system for a component, heat transfer generally adopts three ways: conduction, convection, radiation. In order to ensure good heat dissipation performance of a power device, the power device is mostly directly mounted on a radiator at present, and the radiator is designed according to the heat productivity of the device during operation. However, in some design situations, the power device itself has a small volume, and if the power device is directly mounted on the heat dissipation plate, the product has a large volume and a heavy weight.

Disclosure of Invention

In order to improve the heat dissipation effect of the power device, no matter which heat dissipation mode is adopted, the problem of how to efficiently and quickly transfer heat from a heat source to a heat dissipation body is solved.

the technical scheme of the invention is as follows:

The heat dissipation system of the board-mounted power device is characterized in that: comprises a radiator, a cold plate, a shell and a fan;

The bottom of the power device is additionally provided with a heat conduction insulating gasket, the power device is arranged on a PCB (printed Circuit Board) through a cold plate, and the cold plate is connected with the shell during installation to form a heat conduction mode for heat dissipation; the PCB printed board is a single-sided bonding pad, so that the short circuit phenomenon between a cold plate and the bonding pad is prevented;

A radiator is additionally arranged on the top of the power device to form heat radiation;

The fan provides the forced air supply perpendicular to PCB printed board installation direction, forms the heat dissipation of thermal convection mode.

when the power device works, heat is continuously emitted, on one hand, the heat is dissipated in a heat radiation mode through a radiator at the top of the power device, on the other hand, the heat is conducted to the shell in a heat conduction mode through a cold plate in close contact with the power device, and finally, the heat is sent away through forced ventilation of a fan. Thus, three heat transfer modes of conduction, convection and radiation are combined, and the whole heat dissipation process comprises 4 links: the first is a power device, i.e. a heat source generator; the second is a radiator and a cold plate, i.e. a heat conductor; third is the fan, namely the medium for increasing heat conduction and directing heat conduction; and fourth is the final flow direction of the air, i.e. heat exchange.

Advantageous effects

The invention has the beneficial effects that: the method of combining conduction, convection and radiation is adopted to realize good heat dissipation of the onboard power device, so that the system has the advantages of good heat dissipation, high working efficiency, high reliability, long service life and the like.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of implementing heat dissipation for an on-board power device. Wherein, 1 is a radiator; 2-power tube; 3-cold plate; 4-printed board; 5-the shell.

Detailed Description

the following detailed description of embodiments of the invention is intended to be illustrative, and not to be construed as limiting the invention.

Fig. 1 depicts a schematic heat dissipation diagram of a board-mounted power device. The system comprises a power tube, a radiator, a cold plate, a shell, a fan and the like.

Firstly, install heat conduction insulating pad additional with the whole bottom of power tube to install on PCB printed board through the cold drawing, here PCB printed board's system during, make the PCB board into the single face pad, prevent that cold drawing and pad from taking place the short circuit phenomenon. The top of the power tube is additionally provided with a radiator to increase the radiating area, and the cold plate is finally connected with the shell of the product when being installed. Finally, the heat is conveyed away by a fan. Thus, three heat transfer modes of heat conduction, heat radiation and convection are combined.

according to the basic formula of heat conduction, Q is K × a × Δ T/, where Q represents heat, K is the heat conduction coefficient of the material, Δ T represents the temperature difference between the two ends, and Δ L is the distance between the two ends. Therefore, from the formula, it can be found that the magnitude of heat transfer is proportional to the heat transfer coefficient and the heat transfer area and inversely proportional to the distance. Therefore, by selecting a material having a high heat transfer coefficient, increasing the heat transfer area, and shortening the transfer distance, the higher the energy of heat transfer, the easier it is to carry away heat.

The formula Q for conduction of heat radiation, where Q represents the capacity for heat radiation to be exchanged, is E × S × F × Δ (Ta-Tb), and E is the coefficient of heat radiation of the object surface. In practice, when the object is metal and the surface is smooth, the emissivity is relatively low, and when the metal surface is anodized and colored black, the surface emissivity is increased. S is the surface area of the object, F is a function of the angle of radiative heat exchange and the surface, and Δ (Ta-Tb) is the temperature difference between surface a and surface b. Therefore, the emissivity, the surface area of the object and the temperature are all in direct proportion.

the invention adopts a method of combining conduction, convection and radiation to realize good heat dissipation of the onboard power device, so that the system has the advantages of good heat dissipation, high working efficiency, high reliability, long service life and the like.

although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made in the above embodiments by those of ordinary skill in the art without departing from the principle and spirit of the present invention.

Claims

1. A heat dissipation system of a board-mounted power device is characterized in that: comprises a radiator, a cold plate, a shell and a fan;

A plurality of power devices are arranged on a single cold plate, and a radiator is additionally arranged at the top of each power device to form heat radiation;