CN210807999U

CN210807999U - Aluminum radiator capable of being directly welded

Info

Publication number: CN210807999U
Application number: CN201920718306.9U
Authority: CN
Inventors: 王学华
Original assignee: Beijing Yiwei Xinneng Technology Co ltd
Current assignee: Beijing Yiwei Xinneng Technology Co ltd
Priority date: 2019-05-20
Filing date: 2019-05-20
Publication date: 2020-06-19
Anticipated expiration: 2029-05-20

Abstract

The utility model discloses an aluminum radiator capable of being directly welded, which comprises a radiator main body, a positioning hole and a metal coating; the radiator main body is in a rectangular thick plate shape; the positioning holes are symmetrically arranged on the heat radiation body; the metal coating sets up the central authorities in aluminium radiator main part, the utility model provides a but direct welded aluminium radiator replaces the heat conduction silicone grease material of low thermal conductivity with the weldable metal material of high thermal conductivity, breaks through the bottleneck of power component heat dissipation problem. The thermal conductivity of the contact layer between the power device heat dissipation substrate and the aluminum heat sink is directly improved from the low thermal conductivity of 1-5W/mK to the metal grade ultrahigh thermal conductivity of 250-300W/mK. The heat dissipation capacity of the radiator and the power density of the power assembly are greatly improved.

Description

Aluminum radiator capable of being directly welded

Technical Field

The utility model belongs to the power electronics field, concretely relates to novel heat dissipation technique that is applicable to power components such as converter, dc-to-ac converter, machine controller.

Background

The electric energy conversion components such as a frequency converter, an inverter and a motor controller generally comprise the following two parts:

1. power devices such as IGBT, MOSFET and the like and an electric energy conversion unit formed by a driving circuit thereof; the power conversion and power output device is used for realizing power conversion and power output.

2. And the air cooling or water cooling heat dissipation unit is formed by aluminum profiles or die-cast aluminum. The device is used for rapidly dissipating continuous heat generated by the electric energy conversion unit so as to maintain the temperature of the power device not to exceed the highest allowable operation junction temperature, and thus the power component can continuously operate.

The aluminum radiator is a necessary material for the power component radiator due to low price, high yield and good heat dissipation, and is widely applicable. But the aluminum surface is extremely easy to oxidize and has poor solder wettability, so that the aluminum surface cannot be directly welded with other metal materials.

In the prior art, a power module is directly assembled with a radiator, and a heat dissipation substrate of a power device and the surface of an aluminum radiator are coated with heat-conducting silicone grease. The function of the heat-conducting silicone grease is to exhaust air between the heat-radiating substrate of the power device and the heat sink (because the thermal resistance of the air is very high, the heat-conducting capability is very poor) so as to realize the connection of the micro-gaps of the contact surfaces. However, the thermal conductivity of the heat-conducting silicone grease is 1-5W/mK, and the heat-conducting capability is still poor compared with that of metal (for example, 237W/mK is aluminum). Therefore, the related technology is provided in the industry for coating the heat-conducting silicone grease, and the main purpose is to ensure that air between the heat-conducting silicone grease and a contact surface of a radiator can be effectively discharged when the power transmission piece is assembled; while making the thickness of the heat conductive silicone grease as thin as possible.

The best known company in the field of power electronics, Infineon, germany, developed a precoat thermal grease (TIM) technology and related patents for the application of thermal grease.

The proposed and applied TIM technology does not fundamentally address the heat dissipation problem of power devices. Due to the existence of the heat-conducting silicone grease, the high heat resistance of the contact interface becomes an obstacle that the heat dissipation of the power device cannot exceed all the time.

Disclosure of Invention

The utility model provides a but direct welded aluminium radiator replaces the heat conduction silicone grease material of low thermal conductivity with the weldable metal material of high thermal conductivity, breaks through the bottleneck of power component heat dissipation problem. The thermal conductivity of the contact layer between the power device heat dissipation substrate and the aluminum heat sink is directly improved from the low thermal conductivity of 1-5W/mK to the metal grade ultrahigh thermal conductivity of 250-300W/mK. The heat dissipation capacity of the radiator and the power density of the power assembly are greatly improved.

The utility model provides an aluminum radiator capable of being directly welded, which comprises a radiator main body, a positioning hole and a metal coating; the radiator main body is in a rectangular thick plate shape; the positioning holes are symmetrically arranged on the heat radiation body main body; the metal coating is disposed in the center of the heat sink body.

Preferably, a plurality of radiating fins are arranged at the bottom of the radiator main body.

Preferably, the number of the positioning holes is more than 2.

Preferably, the shape of the positioning hole can adopt various simple shapes such as a circle, a square, a diamond, a plus sign and the like.

Preferably, a mask plate is arranged above the metal coating, the metal coating and the mask plate are directly stacked on the surface of the radiator, and after the positioning holes are self-aligned, metal powder is accelerated to supersonic speed and then is sputter-coated on the aluminum radiator in a metal power spraying mode.

Preferably, the metal coating is a solderable metal such as copper, silver, etc.

Preferably, the coating thickness of the metal coating is 1-10 um.

Preferably, the mask plate and the aluminum radiator are accurately positioned in the spraying area by positioning holes; the occupied area of the positioning holes is 0.25mm²And 9mm²In the meantime.

Preferably, the surfaces of the aluminum heat radiator and the metal coating are polished to realize a flat and smooth weldable metal layer on the aluminum heat radiator.

Compared with the prior art, the utility model relates to a but following beneficial effect of direct welded aluminium radiator:

1. the utility model provides a can directly welded aluminium radiator, the metallic film can be welded in aluminium radiator surface sputtering coating, has broken through aluminium radiator's non-weldability.

2. The utility model provides a but direct welded aluminium radiator, on the metallic film that can weld of aluminium radiator, can realize with the direct welding of power device module.

3. The utility model provides a but direct welded aluminium radiator has realized power module and radiator direct welding, and welding material is the metal, and the metal has the heat conductivity of superelevation, and contact interface heat conductivity improves 60-300 times.

4. The utility model provides a but direct welded aluminium radiator, whole radiating efficiency improves, abandons the heat conduction silicone grease of lower thermal conductivity and uses, and whole radiating efficiency improves about 50% -100%.

5. The utility model provides an aluminum radiator which can be directly welded, and the adopted welding connection mode has long service life; compared with the heat-conducting silicone grease which is easy to volatilize and dry after being applied for a long time, the heat conductivity is further reduced, and the service life of the system is prolonged.

6. The utility model provides an aluminum radiator capable of being directly welded, which adopts a welding connection mode with high system reliability and changes the connection mode of a power module and the radiator; compared with a mechanical connection mode, the system reliability is improved

7. The utility model provides a but direct welded aluminium radiator compares power density with the product of traditional adoption heat conduction silicone grease and improves, and the power component of the same volume exports electric energy, improves 50% -100%.

8. The utility model provides a but direct welded aluminium radiator compares power density with the product that the tradition adopted heat conduction silicone grease and improves, and the system volume reduces, and the same power output, the volume of required system is littleer.

9. The utility model provides a but direct welded aluminium radiator compares power density with the product of traditional adoption heat conduction silicone grease and improves, and radiator material cost reduces by a wide margin.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a method for manufacturing a solderable aluminum heat spreader;

FIG. 2 is a schematic illustration of a solderable aluminum heat spreader prior to polishing;

FIG. 3 is a schematic illustration of a solderable aluminum heat spreader after polishing;

FIG. 4 is a schematic diagram of a finished solderable aluminum heat spreader;

reference numerals: 1-a radiator main body, 2-a positioning hole, 3-a metal coating, 4-a radiating tooth sheet and 5-a mask plate.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person skilled in the art without any creative effort belong to the protection scope of the present invention.

The first embodiment is as follows:

by adopting a metal power spraying technology, the compressed air accelerates the metal powder to reach the supersonic critical speed, and at the speed, the metal particles directly impact the surface of the aluminum radiator and then are physically deformed. The metal particles are flattened on the surface of the substrate and firmly attached, so that a layer of firmly attached metal film can be formed. Due to the compactness of the metal film, basically no boundary interface of two metals exists, and no interface resistance is generated. The metal powder in the patent adopts copper, silver, gold and the like, has good thermal conductivity and has the characteristic of weldability.

As shown in fig. 1, 2, 3 and 4, a directly weldable aluminum heat sink includes an aluminum heat sink 1, a pilot hole 2 and a metal coating 3; the radiator main body 1 is in a rectangular thick plate shape; the positioning holes 2 are symmetrically arranged on the radiator main body 1; the metal coating 3 is provided in the center of the aluminum heat sink body 1.

The bottom of the radiator main body 1 is provided with a plurality of radiating fins 4.

The number of the positioning holes 2 is more than 2, and the shape can adopt various simple shapes such as circle, square, diamond, plus sign and the like.

The metal coating 3 is directly stacked on the surface of the radiator on the mask plate 5, and after the positioning holes 2 are self-aligned, the metal powder is accelerated to the supersonic speed and then is sputtered and coated on the aluminum radiator in a metal power spraying mode.

The metal coating 3 is a solderable metal such as copper, silver, etc.

The mask plate 4 and the aluminum radiator main body 1 are positioned accurately by the positioning holes 2; the occupied area of the positioning hole 2 is 0.25mm²And 9mm²In the meantime.

The coating thickness of the metal coating 3 is 1-10 um.

The surfaces of the radiator main body 1 and the metal coating 3 are polished to realize a flat and smooth weldable metal layer on the aluminum radiator.

A preparation method of a weldable aluminum radiator.

1. And (3) preparing a metal mask plate, wherein a steel metal plate is selected as a mask plate material. The mask plate is provided with a rectangular hollow area, the size of the area is slightly larger than that of the copper substrate of the applied power module, the length and width allowance is 1-5mm, the mask plate is provided with positioning holes, and the positioning holes can be in various simple shapes such as circles, squares, diamonds and plus signs. The number of the positioning holes is more than or equal to two, and the positioning holes are distributed at each diagonal of the mask plate. The smaller the area occupied by the positioning holes, the more accurate the positioning is, and 0.5mm x 0.5mm-3mm x 3mm is better.

2. An aluminum radiator: the radiator body 1 can be made by directly cutting an aluminum profile, and can also be made by adopting a die-casting aluminum preparation method and the like. The shape of the radiator can be a rectangular thick plate shape, and can also be a radiator with various tooth sheet designs.

Positioning marks such as positioning holes and positioning marks are arranged on the radiator; the positioning holes can be drilled for installing screw holes and the like, or can be drilled for positioning the mask plate. The positioning mark can be a laser mark or an automatic spraying consistency mark.

The radiator positioning mark and the mask plate positioning hole can be accurately aligned.

3. Directly stack the mask plate on the radiator surface, locating hole self-alignment.

4. And directly spraying metal powder such as copper and the like on the hollow area of the mask plate by using metal power spraying equipment to form a compact copper metal coating. The thickness of the coating is 1-10 um. The metal power spraying adopts a physical sputtering mode of low temperature, high pressure and high speed, and a compact copper metal layer of 2-5um can be formed downwards on the surface of the aluminum radiator. (as shown in fig. 2 and 3).

5. And (3) performing surface polishing treatment on the radiator to form a copper metal thin layer on the aluminum radiator, wherein the copper metal thin layer can be directly welded with a copper substrate of a power device.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, however, the present invention is not limited to the details of the above embodiments, and the technical concept of the present invention can be within the scope of the present invention to perform various simple modifications to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. The utility model provides a but directly welded aluminium radiator which characterized in that: the aluminum radiator comprises a radiator main body (1), a positioning hole (2) and a metal coating (3); the radiator main body (1) is rectangular; the positioning holes (2) are symmetrically arranged on the radiator main body (1); the metal coating (3) is arranged in the center of the radiator main body (1).

2. A directly weldable aluminium heat sink in accordance with claim 1, wherein: the bottom of the radiator main body (1) is provided with a radiating tooth sheet (4).

3. A directly weldable aluminium heat sink in accordance with claim 1, wherein: the number of the positioning holes (2) is more than 2.

4. A directly weldable aluminium heat sink in accordance with claim 1, wherein: the positioning hole (2) is simple in shape.

5. A directly weldable aluminium heat sink in accordance with claim 1, wherein: a mask plate (5) is arranged above the metal coating (3), and the mask plate (5) and the metal coating (3) are stacked on the surface of the radiator main body (1) together for self-alignment.

6. A directly weldable aluminium heat sink according to claim 5, wherein: the metal coating (3) is a weldable metal.

7. A directly weldable aluminium heat sink in accordance with claim 6, wherein: the thickness of the metal coating (3) is 1-10 um.

8. A directly weldable aluminium heat sink in accordance with claim 1, wherein: the size of the positioning hole (2) is 0.25mm²～9mm²。

9. A directly weldable aluminium heat sink in accordance with claim 1, wherein: the surfaces of the radiator main body (1) and the metal coating (3) are both polished.