Semiconductor plastic package power module with molded creepage convex structure

Abstract

The utility model relates to the technical field of power module packaging, in particular to a semiconductor plastic package power module with a molded creepage convex structure. Comprising a lead frame including a power terminal and a signal terminal; the lead frame is connected with the upper surface of the copper-clad ceramic substrate; the lead frame is connected with one end of the copper-clad ceramic substrate, the lead frame and the copper-clad ceramic substrate are coated in the plastic package body, and a heat dissipation surface of the copper-clad ceramic substrate is exposed out of the bottom of the plastic package body; and the creepage boss is arranged at the bottom of the plastic package body and is positioned between the heat dissipation surface of the copper-clad ceramic substrate and the power terminal. According to the utility model, the creepage boss is arranged between the copper-clad ceramic substrate and the lead frame, so that the creepage distance between the power supply terminal of the module and the copper-clad ceramic substrate can be effectively increased, the voltage class allowed by module packaging is improved, and the reliable mechanical performance of the module is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of power module packaging, in particular to a semiconductor plastic-sealed power module with a molded creepage convex structure. Background Art

[0002] The power semiconductor module is a power electronic converter, whose main function is to convert the frequency and current of electric power to achieve efficient application of electric power. With the gradual popularization of new energy vehicles, in order to achieve more efficient battery charging and discharging efficiency, the voltage level of the automotive electronic control system will gradually increase, which puts higher requirements on the voltage level of the power module and the corresponding electrical insulation. In the prior art, there are two methods to increase the creepage distance of the plastic package. One is to use packaging materials with a higher relative tracking index (CEI), and the other is to directly increase the creepage distance by optimizing the packaging structure. However, the use of new packaging materials poses a greater risk to the reliability of the module system, and the material development and verification cycle is long. Optimizing the packaging structure to increase the creepage distance can quickly achieve an increase in the voltage level of the module, and the risk of module system reliability is also lower. Utility Model Content

[0003] The purpose of the utility model is to provide a semiconductor plastic-encapsulated power module with a molded creepage convex structure to solve the above technical problems;

[0004] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0005] A semiconductor plastic-encapsulated power module with a molded creepage convex structure, comprising:

[0006] A lead frame including power terminals and signal terminals;

[0007] A copper-clad ceramic substrate, wherein the lead frame is connected to an upper surface of the copper-clad ceramic substrate;

[0008] A plastic package, wherein the lead frame is connected to one end of the copper-clad ceramic substrate and the copper-clad ceramic substrate is covered in the plastic package, and the heat dissipation surface of the copper-clad ceramic substrate is exposed at the bottom of the plastic package;

[0009] The creepage boss is arranged at the bottom of the plastic package body and is located between the heat dissipation surface of the copper-clad ceramic substrate and the power terminal.

[0010] Preferably, the creepage boss comprises a first boss and a second boss respectively arranged on both sides of the heat dissipation surface of the copper-clad ceramic substrate, and the first boss and the second boss are parallel to the side edges of the heat dissipation surface of the copper-clad ceramic substrate.

[0011] Preferably, it further comprises a semiconductor chip, which is located in the plastic package and arranged on the copper-clad ceramic substrate, and the electrodes of the semiconductor chip are connected to the lead frame.

[0012] Preferably, the power terminal comprises an emitter power terminal and a collector power terminal respectively arranged on two sides of the plastic package body.

[0013] Preferably, the signal terminal includes a gate signal terminal and an emitter signal terminal which are arranged on the same side as the emitter power terminal.

[0014] Preferably, the copper-clad ceramic substrate comprises:

[0015] Back copper layer;

[0016] An intermediate ceramic layer is disposed on the back copper layer;

[0017] The front copper layer is arranged on the middle ceramic layer.

[0018] Preferably, the back copper layer is the heat dissipation surface of the copper-clad ceramic substrate, the middle ceramic layer and the front copper layer are coated in the plastic package, and at least a portion of the back copper layer is exposed at the bottom of the plastic package.

[0019] Preferably, the creepage boss and the plastic package body are an integrally formed structure.

[0020] Preferably, the side wall of the creepage boss has a set draft angle.

[0021] Preferably, the height of the creepage boss is 1 mm to 2 mm.

[0022] Beneficial effects of the utility model: Due to the adoption of the above technical scheme, the utility model sets a creepage boss between the copper-clad ceramic substrate and the lead frame, which can effectively increase the creepage distance between the module power terminal and the copper-clad ceramic substrate, improve the allowable voltage level of the module package, and ensure that the module has reliable mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of a semiconductor plastic-encapsulated power module in an embodiment of the utility model;

[0024] Figure 2 This is a bottom schematic diagram of a semiconductor plastic-encapsulated power module in an embodiment of the utility model;

[0025] Figure 3 It is a side view of the semiconductor plastic-encapsulated power module in the embodiment of the utility model.

[0026] In the attached figure: 1. Copper-clad ceramic substrate; 2. Lead frame; 21. Collector power terminal; 22. Emitter power terminal; 23. Gate-level signal terminal; 24. Emitter signal terminal; 3. Plastic package; 4. Creepage boss. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0029] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0030] A semiconductor plastic package power module with a molded creepage convex structure, such as Figures 1 to 3 As shown, including,

[0031] Lead frame 2, including power terminals and signal terminals;

[0032] A copper-clad ceramic substrate 1, a lead frame 2 connected to an upper surface of the copper-clad ceramic substrate 1;

[0033] A plastic package body 3, a lead frame 2 connected to one end of the copper-clad ceramic substrate 1 and the copper-clad ceramic substrate 1 is covered in the plastic package body 3, and a heat dissipation surface of the copper-clad ceramic substrate 1 is exposed at the bottom of the plastic package body 3;

[0034] The creepage boss 4 is arranged at the bottom of the plastic package body 3 and is located between the heat dissipation surface of the copper-clad ceramic substrate 1 and the power terminal.

[0035] Specifically, the utility model provides a semiconductor plastic package power module with a molded creepage convex structure, the module body comprises a copper-clad ceramic substrate 1, an internally packaged semiconductor chip, a lead frame 2 for leading out the semiconductor chip electrodes, and a compound plastic package 3 for packaging.

[0036] The utility model provides a boss structure between the copper-clad ceramic substrate 1 and the lead frame 2 at the bottom of the power module. The molded creepage boss 4 can effectively increase the creepage distance between the module power terminal and the pad of the copper-clad ceramic substrate 1, improve the allowable voltage level of the module package, and ensure that the module has reliable mechanical properties.

[0037] In a preferred embodiment, the creepage boss 4 includes a first boss and a second boss respectively disposed on both sides of the heat dissipation surface of the copper-clad ceramic substrate 1 , and the first boss and the second boss are parallel to the side edges of the heat dissipation surface of the copper-clad ceramic substrate 1 .

[0038] Specifically, the creepage boss 4 is located at the bottom of the module, between the power terminal and the pad of the copper-clad ceramic substrate 1, one on each side of the bottom of the power module, and the creepage boss 4 is strip-shaped and arranged along the bottom edge of the power module.

[0039] In a preferred embodiment, it further comprises a semiconductor chip, which is located in the plastic package 3 and arranged on the copper-clad ceramic substrate 1 , and the electrodes of the semiconductor chip are connected to the lead frame 2 .

[0040] In a preferred embodiment, the power terminal includes an emitter power terminal 22 and a collector power terminal 21 respectively disposed on two sides of the plastic package body 3 .

[0041] In a preferred embodiment, the signal terminal includes a gate signal terminal 23 and an emitter signal terminal 24 which are arranged on the same side of the emitter power terminal 22 .

[0042] Specifically, the overall appearance of the module includes a gate-level signal terminal, an emitter signal terminal (also a source signal terminal), an emitter power terminal 22 (also a source power terminal), a plastic package 3, a collector power terminal 21 (also a drain power terminal) and Figure 2 The heat dissipation surface of the copper-clad ceramic substrate 1 at the bottom of the module shown in FIG.

[0043] More specifically, the lead frame 2 of the present invention is a special-shaped structure formed by compression molding.

[0044] In a preferred embodiment, the copper-clad ceramic substrate 1 comprises:

[0045] Back copper layer;

[0046] An intermediate ceramic layer is provided on the back copper layer;

[0047] The front copper layer is arranged on the middle ceramic layer.

[0048] In a preferred embodiment, the back copper layer is the heat dissipation surface of the copper-clad ceramic substrate 1 , the middle ceramic layer and the front copper layer are encapsulated in the plastic package 3 , and at least a portion of the back copper layer is exposed at the bottom of the plastic package 3 .

[0049] In a preferred embodiment, the creepage boss 4 and the plastic package body 3 are an integrally formed structure.

[0050] Specifically, the utility model provides a creepage boss 4, and without changing the power semiconductor packaging material and peripheral dimensions, by changing the outer film structure of the plastic package, the creepage distance between the module power terminal and the heat dissipation welding surface is increased, which is beneficial to the high voltage application of the module.

[0051] The structure of the creepage boss 4 meets the international standard IEC 60664-1 issued by the International Electrotechnical Commission.

[0052] In a preferred embodiment, the side wall of the creepage boss 4 has a set draft angle.

[0053] Specifically, the side wall of the creepage boss 4 is at a certain angle to facilitate demoulding of the power module after injection molding. In this embodiment, the demoulding angle is 15°.

[0054] In a preferred embodiment, the height of the creepage boss 4 is 1 mm to 2 mm; specifically, the height of the creepage boss 4 in this embodiment is 1.2 mm.

[0055] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A semiconductor plastic-encapsulated power module with a molded creepage convex structure, characterized in that: include, A lead frame (2), including power terminals and signal terminals; A copper-clad ceramic substrate (1), wherein the lead frame (2) is connected to the upper surface of the copper-clad ceramic substrate (1); A plastic package (3), wherein the lead frame (2) is connected to one end of the copper-clad ceramic substrate (1) and the copper-clad ceramic substrate (1) is encapsulated in the plastic package (3), and the heat dissipation surface of the copper-clad ceramic substrate (1) is exposed at the bottom of the plastic package (3); A creepage boss (4) is provided at the bottom of the plastic package body (3) and is located between the heat dissipation surface of the copper-clad ceramic substrate (1) and the power terminal.

2. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: The creepage boss (4) comprises a first boss and a second boss respectively arranged on both sides of the heat dissipation surface of the copper-clad ceramic substrate (1), and the first boss and the second boss are parallel to the side edges of the heat dissipation surface of the copper-clad ceramic substrate (1).

3. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: It also comprises a semiconductor chip, which is located in the plastic package (3) and arranged on the copper-clad ceramic substrate (1), and the electrodes of the semiconductor chip are connected to the lead frame (2).

4. The semiconductor plastic-encapsulated power module with a molded creepage convex structure according to claim 1, characterized in that: The power terminal comprises an emitter power terminal (22) and a collector power terminal (21) respectively arranged on two sides of the plastic package (3).

5. The semiconductor plastic package power module with molded creepage convex structure according to claim 4, characterized in that: The signal terminal comprises a gate signal terminal (23) and an emitter signal terminal (24) which are arranged on the same side as the emitter power terminal (22).

6. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: The copper-clad ceramic substrate (1) comprises: Back copper layer; An intermediate ceramic layer is disposed on the back copper layer; The front copper layer is arranged on the middle ceramic layer.

7. The semiconductor plastic package power module with a molded creepage convex structure according to claim 6, characterized in that: The back copper layer is the heat dissipation surface of the copper-clad ceramic substrate (1), the middle ceramic layer and the front copper layer are coated in the plastic packaging body (3), and at least a part of the back copper layer is exposed at the bottom of the plastic packaging body (3).

8. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: The creepage boss (4) and the plastic package body (3) are an integrally formed structure.

9. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: The side wall of the creepage boss (4) has a set draft angle.

10. The semiconductor plastic package power module with a molded creepage convex structure according to claim 1, characterized in that: The height of the creepage boss (4) is 1 mm to 2 mm.

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