Power discrete device module and preparation method thereof

Abstract

The present application relates to a power discrete device module and a preparation method thereof. The power discrete device module includes a substrate, the substrate includes a first metal copper layer, a ceramic layer and a second metal copper layer, the first metal copper layer is arranged on the first side of the ceramic layer, the second metal copper layer is arranged on the second side of the ceramic layer, wherein the first side and the second side are two opposite sides of the ceramic layer; a device unit, the device unit is arranged on the side of the first metal copper layer away from the ceramic layer; and an external soldering piece, the external soldering piece is arranged on the side of the second metal copper layer away from the ceramic layer, and the external soldering piece is used to be welded to the heat sink to achieve heat transfer connection. The built-in ceramic layer has excellent insulation performance, so that when the power discrete device module is welded to the heat sink, no additional insulation treatment is required, thereby greatly shortening the heat dissipation path, achieving lower thermal resistance, and improving the working efficiency of the power discrete device module.

Description

Technical Field

[0001] The present application relates to the technical field of power discrete devices, and in particular to a power discrete device module and a preparation method thereof. Background Art

[0002] ‌Power discrete devices‌ refer to independent electronic devices used to carry high-power signals. They can be used alone or in combination with other discrete devices to complete specific power amplification and switch control circuits. Power discrete devices play a key role in electronic systems and are mainly used for power conversion, power amplification, power switching, line protection and rectification. At present, the terminal applications of most power discrete devices on the market require additional insulation and heat dissipation treatment, which is mainly assembled with the heat sink through external DBC soldering, external ceramic sheet with thermal conductive adhesive welding or insulated thermal conductive adhesive welding.

[0003] However, due to the presence of multi-layer structures in the heat dissipation paths of the above-mentioned methods and the low thermal conductivity of the materials, the heat sink cannot effectively reduce the thermal resistance of the power discrete devices, which greatly affects the working efficiency of the power discrete devices. In addition, since external DBC soldering and external ceramic sheets with thermal conductive adhesive welding require the purchase of materials, it will also lead to increased costs and complex and difficult installation procedures. Summary of the invention

[0004] Based on this, it is necessary to provide a power discrete device module and a preparation method thereof to address the problems that affect the working efficiency of power discrete devices, such as high cost, difficulty in installation and complex procedures.

[0005] In a first aspect of the present application, a power discrete device module is provided, comprising:

[0006] A substrate, the substrate comprising a first metal copper layer, a ceramic layer, and a second metal copper layer, wherein the first metal copper layer is disposed on a first side surface of the ceramic layer, and the second metal copper layer is disposed on a second side surface of the ceramic layer, wherein the first side surface and the second side surface are two opposite sides of the ceramic layer;

[0007] A device unit, wherein the device unit is arranged on a side of the first metal copper layer facing away from the ceramic layer;

[0008] An external welding piece is arranged on the side of the second metal copper layer facing away from the ceramic layer, and the external welding piece is used for welding with the heat sink to achieve heat transfer connection.

[0009] In the power discrete device module of the present solution, the substrate is composed of a ceramic layer and a first metal copper layer and a second metal copper layer respectively connected to opposite sides of the ceramic layer, so that the device unit can be directly mounted on the first metal copper layer, and the external soldering piece is integrated and mounted on the second metal copper layer. In this way, on the one hand, the built-in ceramic layer has excellent insulation performance, so that the power discrete device module does not need additional insulation treatment when it is soldered to the heat sink, thereby greatly shortening the heat dissipation path, achieving lower thermal resistance, and improving the working efficiency of the power discrete device module. On the other hand, it can be directly soldered and fixed to the heat sink with the help of the external soldering piece, which effectively saves the cost of external insulating materials, simplifies the installation process steps, and reduces the difficulty of installation.

[0010] The technical solution of this application is further described below:

[0011] In one embodiment, the external welding piece is connected and fixed to the second metal copper layer by laser welding.

[0012] In one of the embodiments, the external welding piece is provided with a welding hole, and the welding hole is arranged to penetrate the thickness direction of the external welding piece. Laser welding is applied to the welding hole to melt the external welding piece material around the welding hole to form solder, and the solder is connected to the second metal copper layer to form an IMC metal layer, so that the external welding piece and the second metal copper layer are connected as one.

[0013] In one embodiment, the second metal copper layer and the external soldering piece are both rectangular and aligned, and the soldering holes are provided at locations of the external soldering piece near four corners and / or four sides.

[0014] In one of the embodiments, the device unit includes a mounting member and a chip, and the chip is mounted on the first metal copper layer through the mounting member.

[0015] In one embodiment, the mounting member is soldered by solder paste or sintered by silver, and the chip is fixed on the first metal copper layer by soldering by solder paste or sintering by silver.

[0016] In one of the embodiments, the device unit further includes a lead, the lead is provided with a connecting portion, and the lead is welded to the chip through the connecting portion.

[0017] In one embodiment, the device unit further includes a power terminal, the lead wire end is connected to the first metal copper layer, and one end of the power terminal is connected to the first metal copper layer and arranged close to the lead wire end.

[0018] In one embodiment, the other end of the power terminal extends to the outside of the substrate.

[0019] In a second aspect of the present application, there is also provided a method for preparing the power discrete device module as described above, comprising the following steps:

[0020] Providing a substrate, and soldering the chip and the power terminal to the substrate respectively;

[0021] Solder the leads to the chip;

[0022] Plastic encapsulation and rib cutting are performed on the integrated body consisting of substrate, chip, power terminal and lead wire;

[0023] The external welding piece is welded to the substrate to obtain a finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application.

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic diagram of the structure of a power discrete device module described in an embodiment of the present application.

[0027] Figure 2 This is a schematic diagram of the structure of welding and assembling the external welding piece and the second metal copper layer.

[0028] Figure 3 It is a schematic diagram of the structure of the power discrete device module and the columnar heat sink.

[0029] Figure 4 The present invention is a flowchart of a method for preparing a power discrete device module according to an embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 100. Power discrete device module; 10. Substrate; 11. First metal copper layer; 12. Ceramic layer; 13. Second metal copper layer; 20. Device unit; 21. Chip; 22. Solder paste welding or silver sintering; 23. Lead; 231. Connecting part; 24. Power terminal; 30. External solder tab; 31. Solder hole; 32. IMC metal layer; 200. Heat sink. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply 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 application.

[0034] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0038] See also Figure 1 and Figure 2 , is a power discrete device module 100 shown in an embodiment of the present application, which includes a substrate 10, a device unit 20 and an external soldering sheet 30. The substrate 10 is specifically a multi-layer board structure, for example, the substrate 10 in the present application includes a first metal copper layer 11, a ceramic layer 12 and a second metal copper layer 13.

[0039] The first metal copper layer 11, the ceramic layer 12 and the second metal copper layer 13 can be assembled into one body by using one of the processes such as active metal brazing technology and direct bond copper technology to obtain excellent strength and structural stability.

[0040] Specifically, the first metal copper layer 11 is disposed on a first side surface of the ceramic layer 12 , and the second metal copper layer 13 is disposed on a second side surface of the ceramic layer 12 , wherein the first side surface and the second side surface are two opposite sides of the ceramic layer 12 .

[0041] For example, the first side surface and the second side surface are two side surfaces in the thickness direction of the ceramic layer 12 .

[0042] The device unit 20 is arranged on the side of the first metal copper layer 11 away from the ceramic layer 12; the external soldering piece 30 is arranged on the side of the second metal copper layer 13 away from the ceramic layer 12, and the external soldering piece 30 is used for soldering with the heat sink 200 to achieve heat transfer connection.

[0043] The external soldering sheet 30 may be made of any one of tin, copper, antimony, gold, silver, etc., or a combination of at least two or more materials.

[0044] Please continue reading Figures 1 to 3 In summary, the implementation of the technical solution of this embodiment will obtain the following beneficial effects: in the power discrete device module 100 of this solution, the substrate 10 is composed of a ceramic layer 12 and a first metal copper layer 11 and a second metal copper layer 13 respectively connected to opposite sides of the ceramic layer 12, so that the device unit 20 can be directly installed on the first metal copper layer 11, and the external welding piece 30 is integrated and installed on the second metal copper layer 13. In this way, on the one hand, the built-in ceramic layer 12 has excellent insulation performance, so that when the power discrete device module 100 is welded to the heat sink 200, no additional insulation treatment is required, thereby greatly shortening the heat dissipation path, achieving lower thermal resistance, and improving the working efficiency of the power discrete device module 100. On the other hand, with the help of the external welding piece 30, it can be directly welded and fixed to the heat sink 200, effectively saving the cost of external insulating materials, while simplifying the installation process steps and reducing the difficulty of installation.

[0045] On the basis of the above embodiment, the external soldering piece 30 is connected and fixed to the second metal copper layer 13 by laser welding, so as to ensure that the connection strength between the external soldering piece 30 and the substrate 10 is high, the firmness is good, and the overall structural performance is excellent.

[0046] Of course, in other optional embodiments, the external welding piece 30 can also be fixed on the second metal copper layer 13 by means of clamping, screwing, etc., which can be flexibly selected according to actual needs.

[0047] Please continue reading Figure 2 Specifically, the external soldering piece 30 is provided with a soldering hole 31, which is set to penetrate the thickness direction of the external soldering piece 30. Laser welding is applied to the soldering hole 31 to melt the material of the external soldering piece 30 around the soldering hole 31 to form solder, and the solder is connected with the second metal copper layer 13 to form an IMC metal layer 32, so that the external soldering piece 30 and the second metal copper layer 13 are connected as one. This laser welding processing method is highly operable, and the formed IMC metal layer 32 provides sufficient bonding area and connection force between the external soldering piece 30 and the second metal copper layer 13, ensuring that the external soldering piece 30 is firmly and reliably installed.

[0048] ‌IMC metal layer 32 (Intermetallic Compound Layer), also known as intermetallic compound layer, refers to an ordered crystal structure compound formed by metal-to-metal, metal-to-metalloid bonded by metallic bonds or covalent bonds. This compound is usually formed during the welding process, especially between solder and the base metal to be welded. When the heat is sufficient, the tin atoms and the atoms of the welded metal (such as copper and nickel) combine, penetrate, migrate and diffuse with each other, and finally form a layer of compound similar to "tin alloy" between the two.

[0049] Preferably, the second metal copper layer 13 and the external soldering tab 30 are both rectangular and aligned, and the external soldering tab 30 is provided with soldering holes 31 near the four vertices and / or four sides. By increasing the number of soldering holes 31, it is equivalent to increasing the number of IMC metal layers 32 formed by welding, thereby further improving the bonding strength between the external soldering tab 30 and the second metal layer, ensuring that the external soldering tab 30 is firmly installed.

[0050] It should be noted that the shapes of the second metal layer and the external soldering pad 30 can also be selected as triangle, circle, etc. The number and position of the soldering holes 31 can also be flexibly changed according to actual needs, which should be within the protection scope of this application.

[0051] In addition, based on any of the above embodiments, the device unit 20 includes a mounting member and a chip 21, and the chip 21 is mounted on the first metal copper layer 11 through the mounting member. In this way, the chip 21 can be mounted and integrated on the first metal copper layer 11 through the mounting member.

[0052] In practical applications, there may be many possible implementation methods of the mounting parts. For example, in an optional embodiment, the mounting parts are solder paste soldering or silver sintering 22, and the chip 21 is fixed on the first metal copper layer 11 by solder paste soldering or silver sintering 22. The connection force provided by the solder paste soldering or silver sintering 22 enables the chip 21 to be fixed on the surface of the first metal copper layer 11, and this adhesive mounting method does not require drilling or other processing on the chip 21, thereby avoiding physical damage to the chip 21 and ensuring the structural integrity, strength and mechanical properties of the chip 21.

[0053] Alternatively, a positioning hole is opened in the corner area of ​​the chip 21, and a positioning column is provided on the surface of the first metal copper layer 11. The positioning column is inserted into the positioning hole to limit the chip 21 to the first metal copper layer 11; alternatively, the chip 21 can also be fixed to the first metal copper layer 11 by screw connection, snap connection, magnetic connection, etc., which can be flexibly selected according to actual needs and will not be repeated here.

[0054] Please continue reading Figure 1In another optional embodiment, the device unit 20 further includes a lead 23, the lead 23 is provided with a connection portion 231, and the lead 23 is welded to the chip 21 through the connection portion 231. The lead 23 is welded to the chip 21 through the connection portion 231, and can be electrically connected to the chip 21. Preferably, a plurality of chips 21 are provided, and the plurality of chips 21 are arranged in an array structure at a preset interval on the surface of the first metal copper layer 11, and the lead 23 is provided with a plurality of connection portions 231, and the lead 23 connects the plurality of chips 21 in series through the connection portion 231, or a plurality of lead 23 are provided, and the plurality of lead 23 connects different plurality of chips 21 in series.

[0055] In addition, based on any of the above embodiments, the device unit 20 further includes a power terminal 24, the end of the lead 23 is connected to the first metal copper layer 11, and one end of the power terminal 24 is connected to the first metal copper layer 11 and arranged close to the end of the lead 23. Therefore, the power terminal 24 can be connected to an external device to achieve electrical connection between the power discrete device module and the external device.

[0056] Optionally, the power terminal 24 and the external device may be connected and fixed by plugging, welding, or the like, which can be flexibly selected according to actual needs.

[0057] In order to facilitate the connection between the power terminal 24 and an external device, the other end of the power terminal 24 extends to the outside of the substrate 10 .

[0058] Please continue reading Figure 4 In addition to the above, the present application also provides a method for preparing the power discrete device module 100 as above, comprising the following steps:

[0059] S10 : providing a substrate 10 , and soldering the chip 21 and the power terminal 24 to the substrate 10 respectively.

[0060] S20 : ​​welding the lead 23 to the chip 21 .

[0061] S30: performing plastic encapsulation and rib cutting processing on the integrated body composed of the substrate 10, the chip 21, the power terminal 24 and the lead 23.

[0062] S40: Weld the external welding piece 30 to the substrate 10 to obtain a finished product.

[0063] It should be noted that when the user obtains the finished product of the above-mentioned power discrete device module 100, the reflow soldering process can be used to directly solder and install the power discrete device module 100 on the heat sink 200 without additional insulation treatment, which greatly shortens the heat dissipation path, achieves lower thermal resistance, and improves the working efficiency of the power discrete device module 100; and, with the external solder piece 30, it can be directly soldered and fixed to the heat sink 200, which effectively saves the cost of external insulating materials, while simplifying the installation process steps and reducing the difficulty of installation.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A power discrete device module, characterized in that: include: A substrate, the substrate comprising a first metal copper layer, a ceramic layer, and a second metal copper layer, wherein the first metal copper layer is disposed on a first side surface of the ceramic layer, and the second metal copper layer is disposed on a second side surface of the ceramic layer, wherein the first side surface and the second side surface are two opposite sides of the ceramic layer; A device unit, wherein the device unit is arranged on a side of the first metal copper layer facing away from the ceramic layer; An external welding piece, the external welding piece is arranged on the side of the second metal copper layer facing away from the ceramic layer, and the external welding piece is used to be welded to the heat sink to achieve heat transfer connection; The external welding piece is provided with a welding hole, and the welding hole is arranged to penetrate the thickness direction of the external welding piece. Laser welding is applied to the welding hole to melt the external welding piece material around the welding hole to form solder. The solder is connected to the second metal copper layer to form an IMC metal layer, so that the external welding piece and the second metal copper layer are connected as one.

2. The power discrete device module according to claim 1, characterized in that: The external welding piece is connected and fixed to the second metal copper layer by laser welding.

3. The power discrete device module according to claim 2, characterized in that: The second metal copper layer and the external soldering piece are both rectangular and aligned, and the soldering holes are provided at locations of the external soldering piece close to four vertices and / or four sides.

4. The power discrete device module according to claim 1, characterized in that: The device unit includes a mounting member and a chip, and the chip is mounted on the first metal copper layer through the mounting member.

5. The power discrete device module according to claim 4, characterized in that: The mounting piece is soldered with solder paste or sintered with silver, and the chip is fixed on the first metal copper layer by soldering with solder paste or sintering with silver.

6. The power discrete device module according to claim 4, characterized in that: The device unit further includes a lead, wherein the lead is provided with a connecting portion, and the lead is welded to the chip through the connecting portion.

7. The power discrete device module according to claim 6, characterized in that: The device unit further includes a power terminal, a lead end of the lead wire is connected to the first metal copper layer, and one end of the power terminal is connected to the first metal copper layer and is arranged close to the lead end of the lead wire.

8. The power discrete device module according to claim 7, characterized in that: The other end of the power terminal extends to the outside of the substrate.

9. A method for preparing a power discrete device module as claimed in any one of claims 1 to 8, characterized in that: The steps include: Providing a substrate, and soldering the chip and the power terminal to the substrate respectively; Solder the leads to the chip; Plastic encapsulation and rib cutting are performed on the integrated body consisting of substrate, chip, power terminal and lead wire; The external welding piece is welded to the substrate to obtain a finished product.

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