Silicon carbide power module injection mold and silicon carbide power module

Abstract

The present application relates to the technical fields of module injection processing, in particular to a silicon carbide power module injection mold and a silicon carbide power module. The silicon carbide power module comprises a substrate, a lead frame and a signal terminal fixed on the substrate, the signal terminal is arranged vertically to the substrate, the silicon carbide power module injection mold comprises a lower plastic encapsulation module and an upper plastic encapsulation module arranged on the top of the lower plastic encapsulation module, the upper plastic encapsulation module and the lower plastic encapsulation module form a containing cavity for accommodating the silicon carbide power module, the lower plastic encapsulation module and / or the upper plastic encapsulation module is provided with a first through hole in the vertical direction, the first through hole is arranged one by one corresponding to the signal terminal, a sealing assembly is fixed in the first through hole, the sealing assembly is hollow inside, the sealing assembly comprises a sealing ring, and the sealing ring is used for interference fit with the signal terminal during assembly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of module injection molding, in particular to a silicon carbide power module injection mold and a silicon carbide power module. BACKGROUND

[0002] Power semiconductor devices are widely used in computer, network communication, consumer electronics, industrial control, automotive electronics, power systems and other fields. Traditional silicon-based power devices are limited by the inherent physical properties of silicon material and have encountered insurmountable difficulties in high-frequency high-power application fields. Therefore, silicon carbide-based power devices have been popularized. With the characteristics of high breakdown field strength, good thermal stability, high carrier saturation drift speed and high thermal conductivity of silicon carbide material, the energy loss and volume weight of power conversion devices such as inverters and frequency converters can be greatly reduced. It can be predicted that silicon carbide power devices will play an increasingly important role in future energy systems.

[0003] The traditional packaging method of the current silicon carbide power module for vertical exposed signal terminals is mainly to inject the epoxy resin plastic sealing area of the power chip, the substrate and the lead frame to form a specific packaging shape, and then cut the lead frame to form vertical exposed signal terminals for signal connection and communication with other circuit boards. However, since the vertical signal terminals are formed by cutting the lead frame, and the lead frame is located around the substrate, these vertical signal terminals can only be distributed around the periphery of the specific plastic sealing shape, and the position of the vertical exposed signal terminals is relatively fixed and cannot be arbitrarily distributed.

[0004] Therefore, there is an urgent need in the art for a new silicon carbide power module injection mold to solve the above technical problems, so that the signal terminals of the silicon carbide power module can be arbitrarily distributed on the top of the substrate. SUMMARY

[0005] To solve the above technical problems, one technical solution adopted by the present application is: a silicon carbide power module injection mold for injection molding of a silicon carbide power module, the silicon carbide power module comprising a substrate, a lead frame fixedly arranged on the substrate, and a signal terminal, the signal terminal being arranged vertically to the substrate, the silicon carbide power module injection mold comprising a lower plastic sealing module and an upper plastic sealing module arranged on the top of the lower plastic sealing module, the upper plastic sealing module and the lower plastic sealing module surrounding a receiving cavity for accommodating the silicon carbide power module, the lower plastic sealing module and / or the upper plastic sealing module being provided with a first through hole in the vertical direction, the first through hole being arranged one-to-one corresponding to the signal terminal, a sealing assembly being fixedly arranged in the first through hole, the sealing assembly being hollow inside, the sealing assembly comprising a sealing ring, the sealing ring being used for interference fit with the signal terminal during assembly.

[0006] Optionally, the sealing assembly further comprises a female sleeve and a male sleeve, the female sleeve is arranged in the first through hole, the male sleeve and the sealing ring are arranged inside the female sleeve, the sealing ring is arranged at one end of the male sleeve close to the accommodating cavity, the two ends of the sealing ring abut against the female sleeve and the male sleeve respectively, a second through hole is arranged at one end of the female sleeve facing the accommodating cavity, a third through hole is arranged in the sealing ring corresponding to the second through hole, a fourth through hole is arranged in the male sleeve corresponding to the third through hole, the second through hole, the third through hole and the fourth through hole are coaxially arranged, and when assembling, the signal terminal is sequentially inserted into the second through hole, the third through hole and the fourth through hole.

[0007] Optionally, the hole diameter of one end of the second through hole facing the third through hole is greater than the outer diameter of the signal terminal, and the second through hole gradually increases in size from one end close to the third through hole to the direction of the accommodating cavity.

[0008] Optionally, the hole diameter of the third through hole is smaller than the outer diameter of the signal terminal.

[0009] Optionally, the hole diameter of the fourth through hole is greater than the outer diameter of the signal terminal.

[0010] Optionally, the female sleeve and the male sleeve are made of tungsten steel.

[0011] Optionally, the inner wall of the fourth through hole is further attached with a protective layer, and the protective layer is used to prevent the signal terminal from being damaged.

[0012] Optionally, the silicon carbide power module injection mold further comprises a bottom plate, the bottom plate is arranged on the side of the lower plastic packaging module and / or the upper plastic packaging module facing outward, and the bottom plate is used to cooperate with the lower plastic packaging module to fix the sealing assembly.

[0013] Optionally, the upper plastic packaging module or the lower plastic packaging module is further provided with an injection port, the injection port is in communication with the accommodating cavity, and the injection port is used for injection molding into the accommodating cavity.

[0014] The application also provides a silicon carbide power module, comprising a substrate, a lead frame and a signal terminal fixedly arranged on the substrate, the signal terminal is arranged vertically to the substrate, and the silicon carbide power module further comprises a shell formed by injection molding using the silicon carbide power module injection mold as described above.

[0015] The beneficial effects of the present application are: the silicon carbide power module injection mold of the present application, by setting a first through hole corresponding to the signal terminal in the vertical direction in the lower plastic encapsulation module and / or the upper plastic encapsulation module, and setting a sealing assembly in the first through hole, the signal terminal of the silicon carbide power module to be injected is inserted into the sealing ring of the sealing assembly before injection; because the lower plastic encapsulation module is provided with a sealing assembly for inserting the signal terminal, the signal terminal can be directly arranged on the top of the substrate and directly injection molded, without the need to cut the rib to form the signal terminal after injection molding; solve the technical problem that the signal terminal can only be distributed on the side of the substrate together with the lead frame in the prior art, and the signal terminal is formed by cutting and bending after injection; the silicon carbide power module injection molded by the silicon carbide power module injection mold of the present application, the signal terminal can be distributed at any position on the substrate. The design of the interference fit between the sealing ring and the signal terminal can also prevent the epoxy resin from overflowing during injection, resulting in poor conductivity of the signal terminal. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0017] Figure 1 is a structure schematic diagram of a silicon carbide power module not injection molded according to an embodiment of the present application;

[0018] Figure 2 is a structure schematic diagram of a silicon carbide power module injection mold according to an embodiment of the present application;

[0019] Figure 3 is an assembly schematic diagram of a silicon carbide power module injection mold and a silicon carbide power module according to an embodiment of the present application;

[0020] Figure 4 is a structure schematic diagram of a silicon carbide power module after injection molding according to an embodiment of the present application;

[0021] Figure 5 is a structure schematic diagram of a sealing assembly of a silicon carbide power module injection mold according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present application.

[0023] The terms "first", "second", "third" in the present application are only for descriptive purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly and specifically limited. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0024] In this document, reference to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is expressly understood that the embodiments described herein are merely examples from a whole class of comparable embodiments which those skilled in the art will readily appreciate. It is also expressly understood that the methods, compositions, and articles of manufacture described herein are merely examples of comparable methods, compositions, and articles of manufacture which those skilled in the art will readily appreciate.

[0025] Please refer to Figure 1 , Figure 1 is a structure diagram of a silicon carbide power module 100 without injection molding in the embodiments of the present application. The silicon carbide power module 100 without injection molding includes a substrate 1, a lead frame 2 fixedly arranged on the substrate 1, and a signal terminal 3. The signal terminal 3 is arranged vertically to the substrate 1, and the lead frame 2 is arranged at the edge of the substrate 1. The substrate 1 is a direct bonding copper (DBC) substrate, the substrate 1 is provided with a chip and circuit components, the signal terminal 3 is used for communication with an external device, the signal terminal 3 is not connected with the lead frame 2, and can be distributed at any position of the substrate 1, without occupying the position of the side edge of the substrate 1, thereby reducing the installation area required for subsequent installation of the silicon carbide power module 100, and improving flexibility.

[0026] Please refer to Figure 2 , Figure 2is a structural schematic view of a silicon carbide power module injection mold 200 of an embodiment of the present application, which is used for injection molding of a silicon carbide power module 100. The silicon carbide power module injection mold 200 comprises a lower plastic sealing module 20 and an upper plastic sealing module 10 arranged on top of the lower plastic sealing module 20. The upper plastic sealing module 10 and the lower plastic sealing module 20 are in a matching structure and can be tightly assembled together. The upper plastic sealing module 10 and the lower plastic sealing module 20 form an accommodating cavity 30 for accommodating the silicon carbide power module 100. The accommodating cavity 30 is the space for injection molding. The lower plastic sealing module 20 is provided with a first through hole (not shown in the figure) in the vertical direction, which is arranged in one-to-one correspondence with the signal terminal 3. In an optional embodiment, the upper plastic sealing module 10 can also be provided with a first through hole in the vertical direction, which is arranged according to the distribution of the signal terminal 3 of the silicon carbide power module 100. A sealing assembly 21 is fixedly arranged in the first through hole. The sealing assembly 21 is hollow inside and comprises a sealing ring 211, which is used for interference fit with the signal terminal 3 during assembly.

[0027] Please refer to Figure 3 , Figure 3 is an assembly schematic view of the silicon carbide power module injection mold 200 and the silicon carbide power module 100 of an embodiment of the present application. The working principle of the silicon carbide power module injection mold 200 of the embodiment of the present application is as follows: the lower plastic sealing module 20 is provided; the silicon carbide power module 100 to be injection molded is inverted with the signal terminal 3 facing downward; the signal terminal 3 is aligned with the sealing assembly 21, the signal terminal 3 is inserted into the sealing ring 211, and the sealing ring 211 is interference fit with the signal terminal 3; the upper plastic sealing module 10 is closed, and the assembly of the silicon carbide power module 100 is completed; epoxy resin is injected into the accommodating cavity 30; after forming, the silicon carbide power module 100 is taken out, and the injection molding process is completed.

[0028] It should be noted that the distribution position and the number of the sealing assembly 21 of the silicon carbide power module injection mold 200 of the embodiment can also be adjusted according to actual conditions, which is not limited herein. For example, the sealing assembly 21 can also be arranged on the upper plastic sealing module 10, which can be arranged according to the number and the distribution position of the signal terminal 3 of the silicon carbide power module 100.

[0029] The silicon carbide power module injection mold 200 of the embodiment of the present application, by arranging a first through hole corresponding to the signal terminal 3 in the vertical direction in the lower plastic sealing module 20 and / or the upper plastic sealing module 10, and arranging a sealing assembly 21 in the first through hole, the signal terminal 3 of the silicon carbide power module 100 to be injected is inserted into the sealing ring 211 of the sealing assembly 21 before injection; because the lower plastic sealing module 20 is provided with the sealing assembly 21 for inserting the signal terminal 3, the signal terminal 3 can be directly arranged on the top of the substrate 1 and directly injection molded, without the need of cutting the rib to form the signal terminal 3 after injection molding; the technical problem that the signal terminal 3 can only be distributed on the side of the substrate 1 together with the lead frame 2 in the prior art, and the signal terminal 3 is formed by cutting and bending after injection molding is solved, the silicon carbide power module 100 injection molded by the silicon carbide power module injection mold 200 of the present application, the signal terminal 3 can be distributed at any position on the substrate 1, especially on the top of the substrate 1. The interference fit design of the sealing ring 211 and the signal terminal 3 can also prevent the signal terminal 3 from being caused by epoxy resin overflow during injection molding.

[0030] Specifically, please refer to Figure 4 , Figure 4 is a structure schematic diagram of the silicon carbide power module 100 after injection molding. After injection molding, the silicon carbide power module 100 further comprises a shell 4, which is formed by the above-mentioned silicon carbide power module injection mold 200 by injection molding. The signal terminal 3 vertically extends out of the top of the shell 4, and the lead frame 2 is located on the side of the shell 4 and extends out of the shell 4.

[0031] In an optional embodiment, please refer to Figure 5 , Figure 5is a structural schematic view of a sealing assembly 21 of a silicon carbide power module injection mold 200 according to an embodiment of the present application. The sealing assembly 21 further comprises a sub-sleeve 213 and a female sleeve 212, the female sleeve 212 is arranged in the first through hole, the sub-sleeve 213 and the sealing ring 211 are arranged inside the female sleeve 212, the sealing ring 211 is arranged at one end of the sub-sleeve 213 close to the accommodating cavity 30, and the two ends of the sealing ring 211 abut against the female sleeve 212 and the sub-sleeve 213 respectively. A second through hole 2121 is formed at one end of the female sleeve 212 facing the accommodating cavity 30, a third through hole 2111 is formed in the sealing ring 211 corresponding to the second through hole 2121, and a fourth through hole 2131 is formed in the sub-sleeve 213 corresponding to the third through hole 2111. The second through hole 2121, the third through hole 2111 and the fourth through hole 2131 are coaxially arranged, and the signal terminal 3 is sequentially inserted into the second through hole 2121, the third through hole 2111 and the fourth through hole 2131 during assembly. Specifically, the female sleeve 212 and the sub-sleeve 213 are made of tungsten steel, and the sealing ring 211 is made of silica gel.

[0032] Further, the hole diameter of one end of the second through hole 2121 facing the third through hole 2111 is greater than the outer diameter of the signal terminal 3, and the second through hole 2121 gradually increases in size from the end close to the third through hole 2111 to the accommodating cavity 30. Specifically, the hole diameter of one end of the second through hole 2121 facing the third through hole 2111 is slightly larger than the outer diameter of the signal terminal 3, and the second through hole 2121 is in the shape of a "V" on the side facing the accommodating cavity 30. Such a structure is mainly used to guide the signal terminal 3 and facilitate assembly of the silicon carbide power module 100.

[0033] Further, the hole diameter of the third through hole 2111 is smaller than the outer diameter of the signal terminal 3. Through the above arrangement, the sealing ring 211 can be in interference fit with the signal terminal 3, effectively preventing epoxy resin from flowing out of the signal terminal 3.

[0034] Further, the hole diameter of the fourth through hole 2131 is greater than the outer diameter of the signal terminal 3. Through the above arrangement, the signal terminal 3 can be prevented from being scratched during the injection molding process. In order to further improve the protection of the signal terminal 3, a protective layer (not shown in the figure) is further attached to the inner wall of the fourth through hole 2131, which is used to prevent the signal terminal 3 from being damaged. The protective layer is made of silica gel.

[0035] Further, the silicon carbide power module injection mold 200 further comprises a bottom plate 40, which is arranged on the outward side of the lower plastic package module 20. When the upper plastic package module 10 is also provided with a sealing assembly 21, the outward side of the upper plastic package module 10 is also provided with the bottom plate 40. The bottom plate 40 is used to cooperate with the lower plastic package module 20 and / or the upper plastic package module 10 to fix the sealing assembly 21.

[0036] Further, the upper plastic package module 10 or the lower plastic package module 20 is further provided with an injection port (not shown in the figure), which is in communication with the accommodating cavity 30, and is used to inject into the accommodating cavity 30.

[0037] Please refer to Figure 3 The embodiment of the present application further provides a silicon carbide power module 100 formed by the above-mentioned silicon carbide power module injection mold 200, which comprises a substrate 1, a lead frame 2 and a signal terminal 3 fixedly arranged on the substrate 1, the signal terminal 3 is arranged vertically to the substrate 1, and the silicon carbide power module 100 further comprises a shell 4, which is formed by the above-mentioned silicon carbide power module injection mold 200 through injection processing.

[0038] The above-mentioned is only part of the embodiments of the present application, and does not limit the protection scope of the present application, and any equivalent device or equivalent process transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A silicon carbide power module injection mold for injection molding a silicon carbide power module, characterized by, The silicon carbide power module comprises a substrate, a lead frame fixed to the substrate, and a signal terminal vertically arranged on the substrate, and a silicon carbide power module injection mold comprises a lower plastic encapsulation module and an upper plastic encapsulation module arranged on the top of the lower plastic encapsulation module, the upper plastic encapsulation module and the lower plastic encapsulation module form a containing cavity for accommodating the silicon carbide power module, the lower plastic encapsulation module and / or the upper plastic encapsulation module is provided with a first through hole in the vertical direction, the first through hole is arranged one by one with the signal terminal, a sealing assembly is fixedly arranged in the first through hole, the sealing assembly is hollow inside, the sealing assembly comprises a sealing ring, the sealing ring is used for assembly and interference fit with the signal terminal, the sealing assembly further comprises a female sleeve and a male sleeve, the female sleeve is arranged in the first through hole, the male sleeve and the sealing ring are arranged in the female sleeve, the sealing ring is arranged at one end of the male sleeve close to the containing cavity, the two ends of the sealing ring are respectively abutted with the female sleeve and the male sleeve, the female sleeve is provided with a second through hole at one end close to the containing cavity, the sealing ring is provided with a third through hole corresponding to the second through hole, the male sleeve is provided with a fourth through hole corresponding to the third through hole, the second through hole, the third through hole and the fourth through hole are coaxially arranged, and the signal terminal is sequentially inserted into the second through hole, the third through hole and the fourth through hole during assembly.

2. The silicon carbide power module injection mold of claim 1, wherein, The hole diameter of one end of the second through hole close to the third through hole is larger than the outer diameter of the signal terminal, and the second through hole gradually increases from one end close to the third through hole to the containing cavity.

3. The silicon carbide power module injection mold of claim 1, wherein, The hole diameter of the third through hole is smaller than the outer diameter of the signal terminal.

4. The silicon carbide power module injection mold of claim 1, wherein, The hole diameter of the fourth through hole is larger than the outer diameter of the signal terminal.

5. The silicon carbide power module injection mold of claim 1, wherein, The female sleeve and the male sleeve are made of tungsten steel.

6. The silicon carbide power module injection mold of claim 1, wherein, The inner wall of the fourth through hole is further provided with a protective layer for preventing the signal terminal from being damaged.

7. The silicon carbide power module injection mold of claim 1, wherein, The silicon carbide power module injection mold further comprises a bottom plate arranged on the side of the lower plastic encapsulation module and / or the upper plastic encapsulation module, and the bottom plate is used for cooperating with the lower plastic encapsulation module and / or the upper plastic encapsulation module to fix the sealing assembly.

8. The silicon carbide power module injection mold of claim 1, wherein, The upper plastic encapsulation module or the lower plastic encapsulation module is further provided with an injection port, the injection port is communicated with the containing cavity, and the injection port is used for injection molding into the containing cavity.

9. A silicon carbide power module, characterized by, The silicon carbide power module comprises a substrate, a lead frame fixed to the substrate, and a signal terminal vertically arranged on the substrate, and a silicon carbide power module injection mold comprises a lower plastic encapsulation module and an upper plastic encapsulation module arranged on the top of the lower plastic encapsulation module, the upper plastic encapsulation module and the lower plastic encapsulation module form a containing cavity for accommodating the silicon carbide power module, the lower plastic encapsulation module and / or the upper plastic encapsulation module is provided with a first through hole in the vertical direction, the first through hole is arranged one by one with the signal terminal, a sealing assembly is fixedly arranged in the first through hole, the sealing assembly is hollow inside, the sealing assembly comprises a sealing ring, the sealing ring is used for assembly and interference fit with the signal terminal, the sealing assembly further comprises a female sleeve and a male sleeve, the female sleeve is arranged in the first through hole, the male sleeve and the sealing ring are arranged in the female sleeve, the sealing ring is arranged at one end of the male sleeve close to the containing cavity, the two ends of the sealing ring are respectively abutted with the female sleeve and the male sleeve, the female sleeve is provided with a second through hole at one end close to the containing cavity, the sealing ring is provided with a third through hole corresponding to the second through hole, the male sleeve is provided with a fourth through hole corresponding to the third through hole, the second through hole, the third through hole and the fourth through hole are coaxially arranged, and the signal terminal is sequentially inserted into the second through hole, the third through hole and the fourth through hole during assembly.

Images