Substrate for power module, conductive substrate and power module thereof

Abstract

The present invention discloses a substrate for a power module, a conductive substrate and a power module thereof, wherein the substrate comprises an insulating substrate, at least one conductor and at least one mixed solder paste layer. The conductor is arranged on one side of the thickness direction of the insulating substrate, and a plurality of through holes are formed on the conductor, and the plurality of through holes are spaced apart along the length direction of the insulating substrate, and the through holes are suitable for installing the pins of the frame of the power module. The mixed solder paste layer is located between the conductor and the insulating substrate, and the shape of the mixed solder paste layer is adapted to the shape of the conductor, and part of the mixed solder paste layer is opposite to the plurality of through holes in the thickness direction of the insulating substrate. According to the substrate for a power module of the present invention, the pins of the frame of the power module are restricted by the through holes during the welding process, so that relative movement between the frame and the substrate is avoided when welding, the stability of the relative position of the substrate and the pins is ensured, the efficiency of one-time forming when welding the substrate and the pins is improved, the yield rate of the power module is improved, and the risk of scrapping the power module is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power modules, and in particular to a substrate, a conductive base and a power module thereof for a power module. Background Art

[0002] In the field of power semiconductor modules, DBC (Direct Bond Copper, ceramic copper clad laminate) is usually used as a carrier of IGBT chips to increase the heat dissipation and current carrying capabilities of the device. However, the welding area of ​​DBC in the related art is a plane, so during the reflow soldering process, the positioning function of the tooling on the DBC disappears under the action of the molten solder, which easily leads to the offset of the frame pins and the welding area of ​​the DBC after welding, reducing the yield of the power module and increasing the risk of scrapping the power module. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide a substrate for a power module, which ensures the stability of the relative position of the substrate and the pins, improves the efficiency of one-time forming when the substrate and the pins are welded, improves the yield of the power module, and reduces the risk of scrapping the power module.

[0004] Another object of the present invention is to provide a conductive substrate for a power module using the substrate for a power module.

[0005] Another object of the present invention is to provide a power module using the conductive substrate for a power module.

[0006] According to an embodiment of the first aspect of the present invention, a substrate for a power module includes an insulating substrate; at least one conductor, which is arranged on one side of the insulating substrate in the thickness direction, and a plurality of through holes are formed on the conductor, and the plurality of through holes are spaced apart along the length direction of the insulating substrate, and the through holes are suitable for installing pins of a frame of a power module; at least one mixed solder paste layer, which is located between the conductor and the insulating substrate, and the shape of the mixed solder paste layer is adapted to the shape of the conductor, and a portion of the mixed solder paste layer is opposite to the plurality of through holes in the thickness direction of the insulating substrate.

[0007] According to the substrate for the power module according to the embodiment of the present invention, a through hole suitable for installing the pins of the frame of the power module is formed on the conductor. Since the pins of the frame of the power module are restricted by the through hole during the welding process, the pins are prevented from moving significantly, which plays a good positioning role in the installation of the substrate and the frame, and avoids relative movement when the frame and the substrate are welded, thereby ensuring the stability of the relative position of the substrate and the pins, improving the efficiency of one-time forming when welding the substrate and the pins, improving the yield of the power module, and reducing the risk of scrapping the power module.

[0008] According to some embodiments of the present invention, the conductor includes a plurality of sub-conductive parts, the plurality of sub-conductive parts are spaced apart along the length direction of the insulating substrate, and the through hole is formed on each of the sub-conductive parts; the mixed solder paste layer includes a plurality of sub-connecting parts, the plurality of sub-connecting parts are spaced apart along the length direction of the insulating substrate, and the plurality of sub-connecting parts correspond one-to-one to the plurality of sub-conductive parts.

[0009] According to some embodiments of the present invention, during the processing of the substrate, the conductor is firstly cut according to the conductive pattern to obtain a plurality of the sub-conductive parts, and then each of the sub-conductive parts is cut to form the through hole.

[0010] According to some embodiments of the present invention, on a projection plane in the thickness direction of the insulating substrate, an edge of the mixed solder paste layer does not protrude beyond an edge of the conductor.

[0011] According to some embodiments of the present invention, on a projection surface of the insulating substrate in the thickness direction, the mixed solder paste layer covers the bottoms of the plurality of through holes.

[0012] According to an embodiment of the second aspect of the present invention, a conductive substrate for a power module includes a substrate, which is the substrate for a power module according to the embodiment of the first aspect of the present invention; a frame, which is located on one side of the thickness direction of the substrate, and includes a plurality of power pins, the plurality of power pins correspond one-to-one to the plurality of through holes of the substrate, and the connection portion of each of the power pins is fixed in the through hole by solder paste.

[0013] According to some embodiments of the present invention, the solder paste is placed in the through hole by printing or spraying, and at least a portion of the connecting portion is located in the through hole.

[0014] According to some embodiments of the present invention, on a projection plane in a thickness direction of the substrate, a cross-sectional area of ​​the through hole is larger than a cross-sectional area of ​​the connecting portion.

[0015] According to some embodiments of the present invention, in the length direction of the substrate, the minimum distance between the edge of the through hole and the edge of the connecting portion is L1, wherein L1 satisfies: 0.05mm≤L1≤0.1mm; and / or in the width direction of the substrate, the minimum distance between the edge of the through hole and the edge of the connecting portion is L2, wherein L2 satisfies: 0.05mm≤L2≤0.1mm.

[0016] A power module according to an embodiment of a third aspect of the present invention comprises the conductive substrate for a power module according to an embodiment of the second aspect of the present invention.

[0017] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] Figure 1 is a schematic diagram of a substrate according to an embodiment of the present invention;

[0020] Figure 2 is a schematic diagram of an electrical conductor of a substrate according to an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of an insulating substrate and a mixed solder paste layer of a substrate according to an embodiment of the present invention;

[0022] Figure 4 is a schematic diagram of a base plate and a frame of a power module according to an embodiment of the present invention;

[0023] Figure 5 is a partial enlarged view of a substrate and a frame according to an embodiment of the present invention;

[0024] Figure 6 is a side view of a substrate and a frame according to an embodiment of the present invention;

[0025] Figure 7 is a partial enlarged view of a substrate and a frame according to an embodiment of the present invention.

[0026] Reference numerals:

[0027] 100: substrate;

[0028] 1: insulating substrate; 2: conductor; 21: sub-conductive part; 22: through hole; 3: mixed solder paste layer; 31: sub-connecting part;

[0029] 200: conductive substrate;

[0030] 201: frame; 2011: (power) pin; 2012: connection part; 202: solder paste;

[0031] 300: Workwear. DETAILED DESCRIPTION

[0032] Reference below Figure 1-Figure 7 A substrate 100 for a power module according to an embodiment of a first aspect of the present invention is described.

[0033] like Figure 1-Figure 7 As shown, a substrate 100 for a power module according to an embodiment of the first aspect of the present invention includes an insulating substrate 1, at least one conductor 2 and at least one mixed solder paste layer 3.

[0034] Specifically, the conductor 2 is provided in the thickness direction of the insulating substrate 1 (for example, Figure 1 A plurality of through holes 22 are formed on the conductor 2 on one side (in the vertical direction). In the description of the present invention, "a plurality" means two or more. The plurality of through holes 22 are formed along the length direction of the insulating substrate 1 (for example, Figure 4 The through holes 22 are spaced apart from each other in the left and right directions, and are suitable for installing the pins 2011 of the frame 201 of the power module. The mixed solder paste layer 3 is located between the conductor 2 and the insulating substrate 1, and the shape of the mixed solder paste layer 3 is adapted to the shape of the conductor 2. In the thickness direction of the insulating substrate 1, part of the mixed solder paste layer 3 is opposite to the plurality of through holes 22.

[0035] For example, in Figure 1 and Figure 3 In the example, the conductor 2 is pre-fixed on the insulating substrate 1 and then placed in the tooling 300 as a whole, and the conductor 2 and the insulating substrate 1 are connected by the mixed solder paste layer 3. The shape of the mixed solder paste layer 3 is adapted to the shape of the conductor 2, so as to facilitate the conductor 2 to be firmly pre-fixed on the insulating substrate 1, avoid the mixed solder paste of the mixed solder paste layer 3 from leaking out, thereby reducing the waste of the mixed solder paste and ensuring the regularity of the surface of the substrate 100. Among them, the tooling 300 can limit the movement of the insulating substrate 1 and the conductor 2, so that the process of moving the insulating substrate 1 and the conductor 2 to the vacuum brazing furnace can avoid the relative change of the position of the conductor 2 and the insulating substrate 1, thereby improving the yield rate of the substrate 100.

[0036] Reference Figure 1 and Figure 2 Four through holes 22 may be formed on the conductor 2. Similarly, the frame 201 has four power pins 2011. The number of through holes 22 may be the same as the number of power pins 2011. One pin 2011 of the frame 201 of the power module is suitable for being installed in each through hole 22, thereby increasing the connection stability between the conductor 2 and the frame 201 of the power module.

[0037] Part of the mixed solder paste layer 3 is opposite to the plurality of through holes 22, which is conducive to firmly fixing the pins 2011 in the through holes 22 by soldering, that is, the pins 2011 are firmly fixed on the substrate 100, thereby improving the connection stability between the substrate 100 and the frame 201. In the process of connecting the substrate 100 and the frame 201, since the pins 2011 of the frame 201 of the power module are restricted by the through holes 22 during the welding process, the pins 2011 are prevented from moving significantly, and play a good positioning role in the installation of the substrate 100 and the frame 201, and relative movement of the pins 2011 and the substrate 100 is prevented when welding, the stability of the relative position of the substrate 100 and the pins 2011 is ensured, and the efficiency of one-time forming when welding the substrate 100 and the pins 2011 is improved, which can improve the yield of the power module and reduce the risk of scrapping the power module.

[0038] Optionally, the insulating substrate 1 may be an Al2O3 ceramic substrate, but is not limited thereto.

[0039] Optionally, the mixed solder paste layer 3 may be a Sn-based solder, but is not limited thereto.

[0040] The conductor 2 may be a copper plate with a thickness of 0.2 mm. The conductor 2 may be used to install a power chip or to dissipate heat of a power module.

[0041] According to the substrate 100 for the power module according to the embodiment of the present invention, a through hole 22 suitable for installing the pin 2011 of the frame 201 of the power module is formed on the conductor 2. Since the pin 2011 of the frame 201 of the power module is restricted by the through hole 22 during the welding process, the pin 2011 is prevented from moving significantly, which plays a good positioning role in the installation of the substrate 100 and the frame 201, and avoids relative movement between the frame 201 and the substrate 100 when welding, thereby ensuring the stability of the relative position of the substrate 100 and the pin 2011, improving the efficiency of one-time forming when welding the substrate 100 and the pin 2011, improving the yield of the power module, and reducing the risk of scrapping the power module.

[0042] According to some embodiments of the present invention, the conductor 2 includes a plurality of sub-conductive parts 21, which are spaced apart along the length direction of the insulating substrate 1, and each sub-conductive part 21 is formed with a through hole 22. The mixed solder paste layer 3 includes a plurality of sub-connecting parts 31, which are spaced apart along the length direction of the insulating substrate 1, and the plurality of sub-connecting parts 31 correspond one to one to the plurality of sub-conductive parts 21. Figure 1The conductor 2 includes four sub-conductive parts 21, which are spaced apart along the length direction of the insulating substrate 1, and a through hole 22 is formed on each sub-conductive part 21. Correspondingly, each sub-conductive part 21 is connected to a pin 2011 of the frame 201 of the power module. At the same time, the mixed solder paste layer 3 also includes four sub-connecting parts 31, and the four sub-connecting parts 31 correspond to the four sub-conductive parts 21 one by one, so that the sub-conductive part 21 and the insulating substrate 1, as well as the pin 2011 and the insulating substrate 1 can be reliably connected through the mixed solder paste layer 3.

[0043] Furthermore, the plurality of through holes 22 are located in the width direction of the insulating substrate 1 (eg, Figure 4 The same side of the vertical direction). Figure 1 , Figure 2 and Figure 4 The four through holes 22 on the four sub-conductive parts 21 are located on the same side of the width direction of the insulating substrate 1, which is conducive to the installation of the pins 2011, such as the power pins 2011, in the corresponding through holes 22, thereby improving the connection stability and accuracy between each sub-conductive part 21 and the pins 2011 of the frame 201 of the power module.

[0044] According to some embodiments of the present invention, during the processing of the substrate 100, the conductor 2 is first cut according to the conductive pattern to obtain a plurality of sub-conductive parts 21, and then each sub-conductive part 21 is cut to form a through hole 22. In other words, the redundant part of the conductor 2 is removed by laser cutting according to the conductive pattern to process the conductor 2 into a plurality of sub-conductive parts 21. Then, a through hole 22 is cut at a position corresponding to the pin 2011 on each sub-conductive part 21 to ensure the efficiency of one-time forming when the substrate 100 and the pin 2011 are welded, thereby reducing the risk of scrapping the power module.

[0045] In addition, on the projection surface in the thickness direction of the insulating substrate 1, the edge of the mixed solder paste layer 3 does not protrude from the edge of the conductor 2. That is, on the projection surface in the thickness direction of the insulating substrate 1, the edge of the mixed solder paste layer 3 can be flush with the edge of the conductor 2; or, on the projection surface in the thickness direction of the insulating substrate 1, the edge of the mixed solder paste layer 3 is located on the inner side of the edge of the conductor 2.

[0046] Since the mixed solder paste will be melted by high temperature in the vacuum soldering furnace, the area of ​​the mixed solder paste layer 3 is set smaller. While the conductor 2 is firmly soldered to the insulating substrate 1, the liquid mixed solder paste of the mixed solder paste layer 3 is prevented from flowing to the outside of the conductor 2 during the soldering process, thereby reducing the waste of the mixed solder paste and ensuring the regularity of the surface of the substrate 100.

[0047] According to some specific embodiments of the present invention, on the projection surface in the thickness direction of the insulating substrate 1, the mixed solder paste layer 3 covers the bottom of the plurality of through holes 22. That is, a portion of the mixed solder paste layer 3 on the insulating substrate 1 is located on the conductor 2 and the insulating substrate 1, and this portion of the mixed solder paste layer 3 is used to solder the conductor 2 to the insulating substrate 1; the other portion of the mixed solder paste layer 3 covers the entire bottom of the through hole 22, which can increase the contact area between the pin 2011 and the mixed solder paste layer 3, and is used to securely solder the pin 2011 to the insulating substrate 1, so as to achieve a reliable connection between the substrate 100 and the pin 2011.

[0048] In some optional embodiments, the substrate 100 can be a ceramic copper-clad plate. For example, a pad (i.e., a conductor 2) is provided on one side of the insulating substrate 1 in the thickness direction, and a power chip can be arranged on the pad; or, the pad (i.e., the conductor 2) and the heat dissipation layer are respectively provided on both sides of the insulating substrate 1 in the thickness direction, and a power chip can be arranged on the pad, and the surface of the heat dissipation layer away from the pad can be flush with the bottom surface of the plastic package and exposed outside the plastic package. When the power chip generates heat during operation, the heat can be transferred to the heat dissipation layer through the pad and the insulating substrate 1, and the heat dissipation layer exchanges heat with the outside to achieve heat dissipation of the intelligent power module. For example, the materials of the pad, the insulating substrate 1 and the heat dissipation layer can be set to a copper layer, a ceramic layer, and a copper layer, respectively, to facilitate the normal use of the substrate 100.

[0049] The mixed solder paste layer 3 includes CuSnTi solder paste and cuprous oxide, and the mass proportion of cuprous oxide is ɑ, wherein ɑ satisfies: 1%≤ɑ≤2%. When ɑ is less than 1%, the content of cuprous oxide is less, and cuprous oxide cannot be evenly distributed in the CuSnTi solder paste, so that the mixing uniformity of the mixed solder paste layer 3 is poor, which will cause the height of the mixed solder paste layer 3 to be inconsistent (i.e., the height of the weld is inconsistent) during brazing, seriously affecting the flatness of the substrate 100; when ɑ is greater than 2%, the content of cuprous oxide is more, resulting in less content of CuSnTi solder paste, which will reduce the weldability of the mixed solder paste layer 3, thereby reducing the connection reliability of the conductor 2 and the insulating substrate 1. Therefore, by making ɑ satisfy 1%≤ɑ≤2%, while ensuring the flatness of the substrate 100, the connection reliability of the conductor 2 and the insulating substrate 1 can be improved, and the conductor 2 can be prevented from separating from the insulating substrate 1.

[0050] According to some embodiments of the present invention, the particle size of cuprous oxide is d, and d satisfies: 45μm≤d≤65μm. When d<45μm, the particle size of cuprous oxide is small, and the liquid mixed solder paste of the mixed solder paste layer 3 overflows more during brazing, that is, the liquid mixed solder paste overflows more from the conductor 2, and the capillary filling force of the mixed solder paste is large, and the welding void is relatively small, which affects the weldability of the mixed solder paste layer 3; when d>65μm, the particle size of cuprous oxide is large, although the liquid mixed solder paste of the mixed solder paste layer 3 overflows less during brazing, but the capillary filling force of the mixed solder paste is small, and the welding void is relatively large, which also affects the weldability of the mixed solder paste layer 3. Therefore, by making the particle size d of cuprous oxide satisfy 45μm≤d≤65μm, the liquid mixed solder paste of the mixed solder paste layer 3 can be effectively avoided from overflowing during brazing, and the weldability of the mixed solder paste layer 3 is guaranteed, thereby ensuring the connection reliability between the conductor 2 and the insulating substrate 1.

[0051] The conductive substrate 200 for a power module according to the second embodiment of the present invention includes a base plate 100 and a frame 201. Figure 4-Figure 7 , the substrate 100 is a substrate 100 for a power module according to the first embodiment of the present invention. The frame 201 is located on one side of the thickness direction of the substrate 100, and the frame 201 includes a plurality of power pins 2011, and the plurality of power pins 2011 correspond to the plurality of through holes 22 of the substrate 100 one by one, and the connection portion 2012 of each power pin 2011 is fixed in the through hole 22 through solder paste 202. The power pins 2011 in the thickness direction of the insulating substrate 1 correspond to the through holes 22 on the substrate 100, so that the connection between the substrate 100 and the power pins 2011 is achieved by fixed connection through the connection portion 2012 of the power pins 2011 and the solder paste 202 in the through hole 22. Among them, the power pins 2011 are electrically connected to the conductor 2 through the solder paste 202 and the mixed solder paste layer 3.

[0052] According to the conductive substrate 200 for a power module according to an embodiment of the present invention, by adopting the above-mentioned substrate 100, a plurality of through holes 22 on the substrate 100 correspond one-to-one to a plurality of power pins 2011, and solder paste 202 is used to fix the connecting portion 2012 of the power pin 2011 in the through hole 22, thereby improving the structural stability of the conductive substrate 200 and extending the service life of the conductive substrate 200.

[0053] Furthermore, the solder paste 202 is placed in the through hole 22 by printing or spraying, which increases the diversity of placing the solder paste 202 in the through hole 22 and improves the production efficiency of the power module. At least part of the connecting portion 2012 is located in the through hole 22. For example, when pre-fixing the power pin 2011, a part of the connecting portion 2012 can be placed in the through hole 22; or, when pre-fixing the power pin 2011, the connecting portion 2012 can be placed in the through hole 22. In this way, the through hole 22 can effectively limit the movement of the connecting portion 2012 and ensure the stability of the position of the power pin 2011.

[0054] Furthermore, on the projection plane in the thickness direction of the substrate 100, the cross-sectional area of ​​the through hole 22 is larger than the cross-sectional area of ​​the connecting portion 2012. This arrangement facilitates the placement of the connecting portion 2012 in the through hole 22, while allowing a gap between the connecting portion 2012 and the through hole 22, which facilitates the melting of the solder paste 202 to be filled between the through hole 22 and the connecting portion 2012 during reflow soldering, and prevents the liquid solder paste 202 from flowing out of the connecting portion 2012.

[0055] According to some embodiments of the present invention, referring to Figure 5 , in the length direction of the substrate 100, the minimum distance between the edge of the through hole 22 and the edge of the connecting portion 2012 is L1, where L1 satisfies: 0.05mm≤L1≤0.1mm. When L1<0.05mm, the minimum distance between the edge of the through hole 22 and the edge of the connecting portion 2012 is small. When the processing error of the through hole 22 and the connecting portion 2012 increases, the connecting portion 2012 cannot be placed in the through hole 22, which easily causes the power pin 2011 and the substrate 100 to move relative to each other; when L1>0.1mm, the minimum distance between the edge of the through hole 22 and the edge of the connecting portion 2012 is large, the size of the through hole 22 is large, and the melted solder paste 202 may not fill the through hole 22 during reflow soldering, resulting in a depression on the surface of the substrate 100. Therefore, by making L1 satisfy 0.05mm≤L1≤0.1mm, while ensuring the relative position stability of the power pin 2011 and the substrate 100, the flatness of the surface of the substrate 100 can be improved.

[0056] Reference Figure 6 and Figure 7 In the width direction of the substrate 100, the minimum distance between the edge of the through hole 22 and the edge of the connecting portion 2012 is L2, where L2 satisfies: 0.05mm≤L2≤0.1mm. This arrangement can also improve the flatness of the surface of the substrate 100 while ensuring the relative position stability of the power pin 2011 and the substrate 100.

[0057] Optionally, in the thickness direction of the substrate 100 , the minimum distance between the connection portion 2012 and the bottom wall of the through hole 22 may be between 0.1 mm and 0.2 mm.

[0058] A power module according to an embodiment of the third aspect of the present invention comprises a conductive substrate 200 for a power module according to an embodiment of the second aspect of the present invention.

[0059] The power module according to the embodiment of the present invention adopts the conductive substrate 200 , which is beneficial to prolonging the service life of the power module and improving the market competitiveness of the power module.

[0060] Other structures and operations of the power module according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0061] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0063] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0064] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A substrate for a power module, characterized in that: include: Insulating substrate; at least one conductor, the conductor being arranged on one side of the insulating substrate in the thickness direction, the conductor being formed with a plurality of through holes, the plurality of through holes being spaced apart along the length direction of the insulating substrate, the through holes being suitable for mounting pins of a frame of a power module; at least one mixed solder paste layer, the mixed solder paste layer being located between the conductor and the insulating substrate, the shape of the mixed solder paste layer being adapted to the shape of the conductor, and a portion of the mixed solder paste layer being opposite to the plurality of through holes in the thickness direction of the insulating substrate; Wherein, on the projection surface in the thickness direction of the insulating substrate, the edge of the mixed solder paste layer does not protrude from the edge of the conductor; On the projection surface of the insulating substrate in the thickness direction, the mixed solder paste layer covers the bottoms of the plurality of through holes, and the mixed solder paste layer in each through hole is suitable for being connected to the pin via solder paste.

2. The substrate for a power module according to claim 1, characterized in that: The conductor comprises a plurality of sub-conductive parts, the plurality of sub-conductive parts are spaced apart along the length direction of the insulating substrate, and each of the sub-conductive parts is formed with the through hole; The mixed solder paste layer includes a plurality of sub-connection parts, the plurality of sub-connection parts are spaced apart along the length direction of the insulating substrate, and the plurality of sub-connection parts correspond one-to-one to the plurality of sub-conductive parts.

3. The substrate for a power module according to claim 2, characterized in that: During the processing of the substrate, the conductor is firstly cut according to the conductive pattern to obtain a plurality of sub-conductive parts, and then each sub-conductive part is cut to form the through hole.

4. A conductive substrate for a power module, characterized in that: include: A substrate, wherein the substrate is the substrate for a power module according to any one of claims 1 to 3; A frame is located on one side of the substrate in the thickness direction, the frame includes a plurality of power pins, the plurality of power pins correspond one-to-one to the plurality of through holes of the substrate, and a connection portion of each power pin is fixed in the through hole by solder paste.

5. The conductive substrate for a power module according to claim 4, characterized in that: Said The solder paste is placed in the through hole by printing or spraying, and at least part of the connecting portion is located in the through hole.

6. The conductive substrate for a power module according to claim 5, characterized in that: On a projection plane in a thickness direction of the substrate, a cross-sectional area of ​​the through hole is larger than a cross-sectional area of ​​the connecting portion.

7. The conductive substrate for a power module according to claim 5, characterized in that: In the length direction of the substrate, the minimum distance between the edge of the through hole and the edge of the connecting portion is L1, wherein L1 satisfies: 0.05mm≤L1≤0.1mm; and / or In the width direction of the substrate, the minimum distance between the edge of the through hole and the edge of the connecting portion is L2, wherein L2 satisfies: 0.05 mm ≤ L2 ≤ 0.1 mm.

8. A power module, characterized in that: The invention comprises a conductive substrate for a power module according to any one of claims 4 to 7.

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