Power semiconductor module capable of controlling thickness of solder and manufacturing method

Abstract

The invention relates to a power semiconductor module capable of controlling solder thickness and a manufacturing method, the power semiconductor module comprises a metal plate and a power semiconductor module arranged on the metal plate, the power semiconductor module is composed of a semiconductor substrate and a welding layer, the bottom surface of the semiconductor substrate is welded on the top surface of the metal plate through the welding layer, and the welding layer is arranged on the metal plate. And an adjusting mechanism for controlling the thickness of the welding layer is also wrapped in the welding layer. The device has the advantages of being simple and reasonable in structure, practical, convenient to use, capable of guaranteeing working efficiency and manufacturing effect and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of cold source supply, and relates to a power semiconductor module capable of controlling solder thickness and a manufacturing method thereof. Background Art

[0002] Power semiconductor modules work under different working conditions and external environments. There are interactions between mechanical, electrical and thermal inside them, and the internal structure is very important to the reliability of the entire system. To date, welding is still the most commonly used connection technology for power semiconductor modules. Welding is very sensitive to temperature shock and mechanical deformation. There is a risk of delamination between different materials at the welding point, especially when the thickness of the welding layer is uneven, delamination is very likely to occur, seriously affecting the service life of the module. In addition, the metal plate of the power semiconductor module is usually not flat, but intentionally bent. This is to ensure good thermal contact between the module and the heat sink, which causes the melted solder to easily gather in the center during the welding process, resulting in uneven thickness of the solder layer. The larger the module area or the higher the strength of the semiconductor substrate used, the greater the bending of the metal plate, and the more obvious this problem is.

[0003] Therefore, a power semiconductor module and a manufacturing method capable of controlling the solder thickness are designed to overcome the above problems. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a power semiconductor module and a manufacturing method thereof which have a simple and reasonable structure, are practical and convenient, and can control the solder thickness and ensure working efficiency and manufacturing effect.

[0005] The present invention is implemented through the following technical solution: a power semiconductor module capable of controlling solder thickness, comprising a metal plate and a power semiconductor module arranged on the metal plate, wherein the power semiconductor module is composed of a semiconductor substrate and a welding layer, the bottom surface of the semiconductor substrate is welded to the top surface of the metal plate through the welding layer, and an adjustment mechanism for controlling the thickness of the welding layer is also wrapped in the welding layer.

[0006] Preferably, the semiconductor substrate is composed of a first metal layer, a dielectric insulating layer, and a second metal layer arranged in sequence from top to bottom, and the bottom surface of the second metal layer is welded to the top surface of the metal plate through a solder layer.

[0007] Preferably, the adjustment mechanism is a metal wire mesh, which is horizontally placed in the welding layer. The metal wire meshes of different thicknesses are used to assist in adjusting the height of the welding layer and ensure that the thickness of the solder layer is uniform.

[0008] Preferably, the dielectric insulating layer is aluminum oxide, silicon nitride or aluminum nitride ceramic.

[0009] Preferably, the first metal layer and the second metal layer are composed of one or more of copper or copper alloy or aluminum or aluminum alloy.

[0010] Preferably, the welding layer is a sheet solder, and the solder is composed of one or more of Sn, Pb, Ag, Cu, In, Au, Sb, Bi, Al, Si, Ge, and Zn.

[0011] Preferably, the metal mesh is composed of one or more of copper or copper alloy, aluminum or aluminum alloy, silver or silver alloy, gold or gold alloy; and the metal plate is composed of one or more of copper, nickel and aluminum.

[0012] A method for manufacturing a power semiconductor module capable of controlling solder thickness comprises the following steps: 1) On the top surface of the metal plate, a placement area is enclosed by a fixture, a metal wire mesh is placed in the placement area, and then a sheet of solder is arranged above the metal wire mesh; 2) placing a semiconductor substrate on top of the sheet solder and wire mesh; 3) In a reducing gas environment, the sheet solder covers the metal wire mesh to form a solder layer, which is used to join the top surface of the fixed metal plate and the bottom surface of the semiconductor substrate; 4) After welding is completed, remove the clamp to obtain a metal plate welded with a semiconductor substrate.

[0013] Preferably, the thickness of the sheet solder is between 100-400 microns, and the soldering temperature is within the range of 100-350°C.

[0014] Preferably, the thickness of the metal mesh is between 30 and 200 microns.

[0015] The beneficial effects of the present invention are as follows: The present invention can effectively solve the problem that the stratification phenomenon is very likely to occur when the thickness of the solder layer is uneven by arranging the metal wire mesh in the solder layer, thereby improving the service life of the manufactured semiconductor module to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the overall structure of the present invention; Figure 2 This is step 1 of the preparation method of the present invention; Figure 3 This is step 2 of the preparation method of the present invention; Figure 4 This is step three of the preparation method of the present invention; Figure 5 This is step 4 of the preparation method of the present invention. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0018] In the description of the present invention, it is necessary to understand that the orientation or position relationship indicated by the terms such as "up", "down", "left", "right", "inside", "outside", "horizontal" and "vertical" is based on the orientation or position relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or original referred to must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0019] The present invention will be described in detail below with reference to the accompanying drawings: Figure 1 As shown, a power semiconductor module capable of controlling solder thickness comprises a metal plate 1 and a power semiconductor module arranged on the metal plate 1, characterized in that: the power semiconductor module consists of a semiconductor substrate 4 and a welding layer 2, the bottom surface of the semiconductor substrate 4 is welded to the top surface of the metal plate 1 through the welding layer 2, and an adjustment mechanism for controlling the thickness of the welding layer 2 is also wrapped in the welding layer 2.

[0020] The semiconductor substrate 4 is composed of a first metal layer 41 , a dielectric insulating layer 42 and a second metal layer 43 arranged in sequence from top to bottom, and the bottom surface of the second metal layer 43 is soldered to the top surface of the metal plate 1 through the solder layer 3 .

[0021] The adjustment mechanism is a metal mesh 3, which is horizontally placed in the welding layer 2. The metal mesh 3 of different thicknesses is used to assist in adjusting the height of the welding layer 2 and ensure the uniform thickness of the solder layer 3. The dielectric insulating layer 42 is aluminum oxide, silicon nitride or aluminum nitride ceramics. The first metal layer 41 and the second metal layer 43 are composed of one or more groups of copper or copper alloy or aluminum or aluminum alloy, and can also be adjusted according to actual conditions without any limitation.

[0022] The welding layer 2 is a sheet solder, and the solder is composed of one or more of Sn, Pb, Ag, Cu, In, Au, Sb, Bi, Al, Si, Ge, and Zn, including PbSnAg, SnAg, SnPb alloys, etc. The metal wire mesh 3 is composed of one or more of copper or copper alloy, aluminum or aluminum alloy, silver or silver alloy, or gold or gold alloy; the metal plate 1 is composed of one or more of copper or nickel and aluminum materials.

[0023] like Figure 2-5 As shown, a method for manufacturing a power semiconductor module capable of controlling solder thickness comprises the following steps: 1) On the top surface of the metal plate 1, a clamp 5 is used to enclose a placement area, a metal wire mesh 3 is placed in the placement area, and then a sheet of solder is arranged above the metal wire mesh 3; 2) placing the semiconductor substrate 4 on the top surface of the sheet solder and the wire mesh 3; 3) In a reducing gas environment, the sheet solder covers the metal mesh to form a solder layer 2, which is used to join the top surface of the fixed metal plate 1 and the bottom surface of the semiconductor substrate 4; 4) After welding is completed, the fixture 5 is removed to obtain the metal plate 1 welded with the semiconductor substrate 4.

[0024] The sheet solder is a sheet alloy solder without any flux added and having a liquidus temperature of 150-450° C., a thickness of 100-400 μm, and a welding temperature of 100-350° C. The thickness of the metal mesh 3 is between 30-200 μm.

[0025] The specific embodiments described herein are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A power semiconductor module capable of controlling solder thickness, comprising a metal plate (1) and a power semiconductor module arranged on the metal plate (1), characterized in that: The power semiconductor module is composed of a semiconductor substrate (4) and a welding layer (2); the bottom surface of the semiconductor substrate (4) is welded to the top surface of the metal plate (1) via the welding layer (2); and an adjustment mechanism for controlling the thickness of the welding layer (2) is also enclosed in the welding layer (2).

2. The power semiconductor module with controllable solder thickness according to claim 1, characterized in that: The semiconductor substrate (4) is composed of a first metal layer (41), a dielectric insulating layer (42) and a second metal layer (43) which are arranged in sequence from top to bottom, and the bottom surface of the second metal layer (43) is welded to the top surface of the metal plate (1) via a solder layer (3).

3. The power semiconductor module with controllable solder thickness according to claim 1, characterized in that: The adjustment mechanism is a metal wire mesh (3), which is horizontally placed in the welding layer (2). The metal wire mesh (3) of different thicknesses is used to assist in adjusting the height of the welding layer (2) and ensure that the thickness of the solder layer (3) is uniform.

4. The power semiconductor module with controllable solder thickness according to claim 2, characterized in that: The dielectric insulating layer (42) is aluminum oxide, silicon nitride or aluminum nitride ceramic.

5. The power semiconductor module with controllable solder thickness according to claim 2, characterized in that: The first metal layer (41) and the second metal layer (43) are composed of one or more of copper or copper alloy or aluminum or aluminum alloy.

6. The power semiconductor module with controllable solder thickness according to claim 3, characterized in that: The welding layer (2) is a sheet-shaped solder, and the solder is composed of one or more of Sn, Pb, Ag, Cu, In, Au, Sb, Bi, Al, Si, Ge, and Zn.

7. The power semiconductor module with controllable solder thickness according to claim 3, characterized in that: The metal wire mesh (3) is composed of one or more of copper or copper alloy, aluminum or aluminum alloy, silver or silver alloy, or gold or gold alloy; and the metal plate (1) is composed of one or more of copper or nickel and aluminum.

8. A method for manufacturing a power semiconductor module with controllable solder thickness as claimed in any one of claims 1 to 7, characterized in that: The following steps are included: 1) On the top surface of the metal plate (1), a clamp (5) is used to enclose a placement area, a metal wire mesh (3) is placed in the placement area, and then a sheet of solder is arranged above the metal wire mesh (3); 2) placing a semiconductor substrate (4) on the top surface of the sheet solder and the wire mesh (3); 3) in a reducing gas environment, the sheet solder covers the metal wire mesh to form a solder layer (2), the solder layer (2) being used to join the top surface of the fixed metal plate (1) and the bottom surface of the semiconductor substrate (4); 4) After welding is completed, the clamp (5) is removed to obtain a metal plate (1) welded with a semiconductor substrate (4).

9. The method according to claim 8, characterized in that: The thickness of the sheet solder is between 100-400 microns, and the soldering temperature is within the range of 100-350°C.

10. The manufacturing method according to claim 8, characterized in that: The thickness of the metal wire mesh (3) is between 30 and 200 micrometers.

Images