阅读说明：本技术 功率模块内部连接铜片及其制备方法、功率半导体模块 (Power module internal connection copper sheet, preparation method thereof and power semiconductor module ) 是由 洪旭 梁小广 丁烜明 于 2021-08-23 设计创作，主要内容包括：本发明提供了一种功率模块内部连接铜片及其制备方法、功率半导体模块,包括铜板、第一铜带及第二铜带,所述第一铜带和所述第二铜带间隔设置在所述铜板上；所述第一铜带和所述第二铜带均为弧形；所述第一铜带的两端均连接设置在所述铜板上,所述第二铜带的两端均连接设置在铜板上。本发明减小模块内铜板二次成型难度,使具备批量生产能力。(The invention provides a power module internal connection copper sheet, a preparation method thereof and a power semiconductor module, wherein the power module internal connection copper sheet comprises a copper sheet, a first copper strip and a second copper strip, wherein the first copper strip and the second copper strip are arranged on the copper sheet at intervals; the first copper strip and the second copper strip are both arc-shaped; the two ends of the first copper strip are connected and arranged on the copper plate, and the two ends of the second copper strip are connected and arranged on the copper plate. The invention reduces the secondary forming difficulty of the copper plate in the module and enables the module to have batch production capacity.)

1. The internal connection copper sheet of the power module is characterized by comprising a copper sheet (1), a first copper strip (2) and a second copper strip (3), wherein the first copper strip (2) and the second copper strip (3) are arranged on the copper sheet (1) at intervals;

the first copper strip (2) and the second copper strip (3) are both arc-shaped; the two ends of the first copper strip (2) are connected and arranged on the copper plate (1), and the two ends of the second copper strip (3) are connected and arranged on the copper plate (1).

2. The power module internal connection copper sheet according to claim 1, wherein a through hole (4) is provided on the copper sheet (1) at a position corresponding to a lower portion of the first copper tape (2) and the second copper tape (3).

3. The power module internal connection copper strip according to claim 1, wherein the first copper strip (2) and the second copper strip (3) are provided in one piece.

4. The power module internal connection copper sheet according to claim 1, characterized in that the copper sheet (1) is arranged hollow.

5. The power module internal connection copper strip of claim 1, wherein the width of the first copper strip (2) is 2000um wide and the thickness of the first copper strip (2) is 200 um.

6. The power module internal connection copper strip according to claim 1, wherein the width of the second copper strip (3) is 2000um wide and the thickness of the second copper strip (3) is 200 um.

7. The preparation method of the internal connection copper sheet of the power module based on the claim 1 is characterized by comprising the following steps:

step 1: connecting the arc-shaped first copper strip (2) and the arc-shaped second copper strip (3) to the copper plate (1) through a binding bonding process;

step 2: inserting corresponding metal strips (5) from the side surfaces of the first copper strip (2) and the second copper strip (3) respectively to support the first copper strip (2) and the second copper strip (3);

and step 3: and positioning the copper plate (1) on a forming jig, and performing press forming through the forming jig.

8. The preparation method of the internal connection copper sheet of the power module based on the claim 2 is characterized by comprising the following steps:

step 1: the arc-shaped first copper strip (2) and the arc-shaped second copper strip (3) are placed corresponding to the through holes (4) on the copper plate (1),

step 2: connecting the first copper strip (2) and the second copper strip (3) on the copper plate (1) through a binding bonding process;

and step 3: penetrating and fixing a metal strip (5) which needs to support the first copper strip (2) and the second copper strip (3) from the through hole (4) to support the first copper strip (2) and the second copper strip (3);

and 4, step 4: and positioning the copper plate (1) on a forming jig, and performing press forming through the forming jig.

9. The preparation method of the internal connection copper sheet of the power module based on claim 3 is characterized by comprising the following steps:

step 1: a looper is additionally arranged on the welding head;

step 2: binding a copper strip on the copper plate (1);

and step 3: and (4) carrying out wire drawing arc on the copper strip, and forming into a final platform shape in one step.

10. A power semiconductor module characterized by comprising the power module internal connection copper sheet according to any one of claims 1 to 6.

Technical Field

The invention relates to the technical field of power semiconductor module packaging, in particular to a power module internal connection copper sheet, a preparation method thereof and a power semiconductor module.

Background

In power supply and power electronic converter applications, power semiconductor (IGBT, MOSFET, SiC, GaN and the like) devices are widely adopted, and copper sheet technology is used for packaging internal connection of a module generally used in occasions with high power.

The strong conductivity of copper can reduce the on-resistance and parasitic inductance, and the contact area of the copper frame and the chip is large, and the thermal expansion coefficient is 16.9x10-6/K and is far lower than that of the traditional aluminum binding wire, so that the power cycle life can be prolonged. However, the copper sheets for welding require hollow design in production and processing to reduce the total weight, so that chips are prevented from being crushed during welding or under thermal stress, secondary forming is required under the requirement of flatness control among the copper bumps, but due to the process deviation of radian and the design requirement of multidirectional binding line positions, great complexity is brought to secondary forming processing, and finally, the UPH yield is low, the labor cost is increased, and the yield is poor, so that the copper sheets do not have batch productivity.

Patent document No. CN107742790A discloses a quick connection copper sheet for electronic connector and a connection terminal thereof, which comprises a connection copper sheet and a connection terminal, wherein the connection copper sheet is of a symmetrical structure and comprises a clamping part, a guiding part and a wiring part, the clamping part comprises a first clamping plate and a second clamping plate, the guiding part comprises 2 parallel guiding plates, the cross section of the wiring part is a hollow isosceles trapezoid, and the connection terminal is in a circular truncated cone shape. However, this patent document still has the disadvantages of low yield, high labor cost, and poor yield, and thus has no mass productivity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an internal connection copper sheet of a power module, a preparation method thereof and the power semiconductor module.

The internal connection copper sheet of the power module comprises a copper sheet, a first copper strip and a second copper strip, wherein the first copper strip and the second copper strip are arranged on the copper sheet at intervals;

the first copper strip and the second copper strip are both arc-shaped; the two ends of the first copper strip are connected and arranged on the copper plate, and the two ends of the second copper strip are connected and arranged on the copper plate.

Preferably, a through hole is formed in the copper plate at a position corresponding to the lower part of the copper strip.

Preferably, the first copper strip and the second copper strip are integrally formed.

Preferably, the width of the first copper strip is 2000um wide, and the thickness of the first copper strip is 200 um.

Preferably, the width of the second copper strip is 2000um wide.

Preferably, the second copper strip has a thickness of 200 um.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: connecting the arc-shaped first copper strip and the arc-shaped second copper strip to the copper plate through a binding bonding process;

step 2: inserting corresponding metal strips from the side surfaces of the first copper strip and the second copper strip to support the first copper strip and the second copper strip respectively;

and step 3: and positioning the copper plate on a forming jig, and performing press molding through the forming jig.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: the arc-shaped first copper strip and the arc-shaped second copper strip are placed corresponding to the through holes on the copper plate,

step 2: connecting the first copper strip and the second copper strip on the copper plate through a binding bonding process;

and step 3: penetrating and fixing a metal strip needing to support the first copper strip and the second copper strip from the perforation, and supporting the first copper strip and the second copper strip;

and 4, step 4: and positioning the copper plate on a forming jig, and performing press molding through the forming jig.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: a looper is additionally arranged on the welding head;

step 2: binding a copper strip on the copper plate;

and step 3: and (4) carrying out wire drawing arc on the copper strip, and forming into a final platform shape in one step.

The invention also provides a power semiconductor module which comprises the power module internal connection copper sheet.

Compared with the prior art, the invention has the following beneficial effects:

1. the invention reduces the weight of the copper plate for internal electrical connection, thereby reducing the mechanical pressure fracture to the chip when the copper plate is welded with the chip;

2. the invention reduces the complexity of the machining process during secondary forming of the binding copper plate. The yield is improved by about 10 times, and the forming yield is improved by about 10 percent;

3. the invention reduces the secondary forming difficulty of the copper plate in the module and enables the module to have batch production capacity.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic structural diagram of a copper sheet connected to the inside of a power module according to a first embodiment of the present invention;

fig. 2 is a schematic view illustrating a process of connecting copper sheets inside the power module according to the first embodiment of the invention;

fig. 3 is a schematic view illustrating an installation of a copper sheet connected to the inside of the power module according to the first embodiment of the present invention;

fig. 4 is a schematic structural diagram of a copper sheet connected to the inside of the power module according to the second embodiment of the present invention;

fig. 5 is a schematic view illustrating a process of connecting copper sheets inside the power module according to the second embodiment of the invention;

fig. 6 is a schematic view illustrating an installation of a copper sheet connected to the inside of the power module according to the second embodiment of the present invention;

fig. 7 is a schematic processing diagram of a copper sheet connected to the inside of a power module according to a third embodiment of the present invention.

The figures show that:

copper plate 1 is perforated 4

First copper strip 2 and metal strip 5

Second copper strip 3

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Example 1:

as shown in fig. 1 to 3, the internal connection copper sheet of the power module provided by the invention comprises a copper sheet 1, a first copper strip 2 and a second copper strip 3, wherein the first copper strip 2 and the second copper strip 3 are arranged on the copper sheet 1 at intervals, and the first copper strip 2 and the second copper strip 3 are both arc-shaped; the both ends of first copper strips 2 all connect the setting on copper 1, and the both ends of second copper strips 3 all connect the setting on copper 1. The copper plate 1 is arranged hollow. The width of the first copper strip 2 is 2000um wide, and the thickness of the first copper strip 2 is 200 um. The width of the second copper strip 3 is 2000um wide, and the thickness of the second copper strip 3 is 200 um.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: connecting the arc-shaped first copper strip 2 and the arc-shaped second copper strip 3 to the copper plate 1 through a binding bonding process;

step 2: inserting corresponding metal strips 5 from the side surfaces of the first copper strip 2 and the second copper strip 3 to support the first copper strip 2 and the second copper strip 3 respectively;

and step 3: and (4) positioning the copper plate 1 on a forming jig, and performing press molding through the forming jig.

The embodiment reduces the secondary forming difficulty of the copper plate in the module, and the mass production capacity is achieved.

In a preferred embodiment, a copper strip with a thickness of 2000um or 200um is connected to a solid copper plate through a binding bonding process, the copper strip is arc-shaped, corresponding metal strips are respectively inserted from the side surfaces of the wire arc to support the wire arc, and finally, the copper strip is formed through pressing by a forming jig with a specific height, as shown in fig. 1 and 2. The formed copper plate is connected to the chip surface by soldering, as shown in fig. 3.

Example 2:

as shown in fig. 4 to 6, the difference from the embodiment 1 is that the copper plate 1 is provided with through holes 4 at positions corresponding to the lower portions of the first copper strips 2 and the second copper strips 3.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: the arc-shaped first copper strips 2 and the arc-shaped second copper strips 3 are arranged corresponding to the through holes 4 on the copper plate 1,

step 2: connecting the first copper strip 2 and the second copper strip 3 on the copper plate 1 through a binding bonding process;

and step 3: a metal strip 5 which needs to support the first copper strip 2 and the second copper strip 3 penetrates through the through hole 4 and is fixed, and the first copper strip 2 and the second copper strip 3 are supported;

and 4, step 4: and (4) positioning the copper plate 1 on a forming jig, and performing press molding through the forming jig.

This embodiment is through carrying out fretwork to the raw and other materials copper plate under binding the ribbon and handling, considers the punching press to design the requirement of copper trompil and thickness, and secondary operation inserts the processing from many times side orientation simultaneously and inserts the shaping processing on disposable tool base.

In a preferred embodiment, the solid copper plate corresponding to the lower part of the wire arc is subjected to hole opening design and processing, then a copper strip with the width of 2000um and the thickness of 200um is connected to the copper plate through a binding bonding process, the copper strip is arc-shaped, a metal strip needing to support the wire arc is extended out from the lower part of a jig and fixed at one time, then the hole opening copper plate welded with the binding wire is positioned on a forming jig, and thus continuous pressing molding operation can be performed, as shown in fig. 4 and 5. The formed copper plate is bonded to the chip surface by soldering, as shown in fig. 6.

Example 3:

as shown in fig. 3 and 7, the difference from embodiment 1 is that the first copper tape 2 and the second copper tape 3 are integrally formed.

The invention also provides a preparation method of the internal connection copper sheet based on the power module, which comprises the following steps:

step 1: a looper is additionally arranged on the welding head;

step 2: binding a copper strip on the copper plate 1;

and step 3: and (4) carrying out wire drawing arc on the copper strip, and forming into a final platform shape in one step.

In the process of welding the binding wire or ribbon to the copper plate, the embodiment is additionally provided with loop forming for one-time forming through wire welding equipment, and secondary forming processing is not needed.

In a preferred embodiment, in the process of welding the binding wire or ribbon to the copper plate, a loop former is additionally arranged on the welding head of the wire welding equipment, and the wire arc is bound and formed into a final platform shape at one time, as shown in fig. 7. And attached to the chip surface by soldering, as shown in fig. 3.

The invention also provides a power semiconductor module which comprises the power module internal connection copper sheet.

The invention reduces the weight of the copper plate for internal electrical connection, thereby reducing the mechanical fracturing to the chip when the copper plate is welded with the chip, reducing the complexity of the machining process when the copper plate is bound for secondary forming, improving the yield by about 10 times and improving the forming yield by about 10 percent.

In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.