Injection molding packaging structure

Abstract

The utility model relates to an injection molding packaging structure which comprises a bottom plate, a copper-clad ceramic substrate is welded on the top end face of the bottom plate, a power device module is welded on the copper-clad ceramic substrate, the top of the bottom plate is connected with an injection molding shell in a heat sealing mode, and the injection molding shell wraps the power device module. A plurality of signal terminals used for controlling signal transmission, an input terminal unit used for being connected with an input power supply and an output terminal unit used for outputting output signals are arranged between the bottom plate and the injection molding shell. By arranging the injection molding shell, air and water vapor in the power device module can be eliminated, so that the performance of the packaged silicon carbide power device is improved; and meanwhile, the injection molding shell is in direct contact with the surface of the power device module, so that the heat dissipation efficiency of the power device module can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of integrated circuit chip packaging, in particular to an injection molding packaging structure. Background Art

[0002] Silicon carbide (SiC) power devices have excellent electronic properties, including high electron mobility and high current density, which can achieve higher operating frequency and higher power density, and are therefore widely used in electric vehicles.

[0003] In the prior art, the encapsulation of silicon carbide power devices usually achieves the sealing function through the potting process, that is, after the silicon carbide chip is wired, the terminals and the formed shell are installed on the base plate, and then the sealant is poured between the shell and the base plate to protect the chip and the bonding wire. However, during the potting process, the sealant is prone to produce defects such as bubbles and water inclusions, which affect the performance of the encapsulated silicon carbide power device; at the same time, during the packaging bonding, the bonding is directly performed on the aluminum layer of the silicon carbide chip, and the thermal resistance is relatively high, resulting in poor heat dissipation performance of the silicon carbide power device. Utility Model Content

[0004] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides an injection molding packaging structure. By providing an injection molding shell, the air and water vapor inside the power device module can be removed, thereby improving the performance of the encapsulated silicon carbide power device; at the same time, the injection molding shell is in direct contact with the surface of the power device module, which can improve the heat dissipation efficiency of the power device module.

[0005] The technical solution adopted by the utility model is as follows:

[0006] An injection molding packaging structure comprises a bottom plate, a copper-clad ceramic substrate is welded to the top end surface of the bottom plate, a power device module is welded to the copper-clad ceramic substrate, an injection molding shell is heat-sealed to the top of the bottom plate, and the injection molding shell wraps the power device module;

[0007] A plurality of signal terminals for controlling signal transmission, an input terminal unit for connecting to an input power source, and an output terminal unit for outputting output signals are arranged between the bottom plate and the injection-molded housing.

[0008] As a further improvement of the above technical solution:

[0009] The injection molded housing also wraps the copper-clad ceramic substrate.

[0010] The injection molded housing wraps around the top and sides of the base plate.

[0011] The surface roughness of the copper-clad ceramic substrate is 6.3 μm.

[0012] The input terminal unit includes at least two power terminals, and the output terminal unit includes at least one power terminal.

[0013] The structure of a single power terminal is as follows: it includes a welding section for welding with a copper-clad ceramic substrate, and a wiring section for connecting with an external signal line, wherein the wiring section and the welding section are connected via a transition section;

[0014] The welding section is provided with a plurality of notches, thereby increasing the contact area between the welding section and the solder;

[0015] The transition section is provided with at least one through hole and a plurality of V-shaped grooves, and the contact area between the transition section and the injection molded housing is increased by the through hole and the V-shaped grooves;

[0016] A wiring hole is provided on the end surface of the wiring segment, and the wiring hole is used for connecting with an external signal line.

[0017] The notch is a semicircular groove.

[0018] The notch is a round hole.

[0019] The power device module includes several silicon carbide modules, and a single silicon carbide module includes a silicon carbide chip. The collector of the silicon carbide chip is bonded and welded on a copper-clad ceramic substrate, and the emitter of the silicon carbide chip is led out through several copper wires.

[0020] It also includes a plurality of gate resistors, each of which corresponds to a gate of the silicon carbide chip one by one, and a single gate resistor is bonded to the gate of the corresponding silicon carbide chip via an aluminum wire.

[0021] A copper sheet for leading out copper wires is welded on the collector of each silicon carbide chip.

[0022] The injection molded housing also completely wraps the copper-clad ceramic substrate.

[0023] The injection molded housing wraps around the top and sides of the base plate.

[0024] The surface roughness of the copper-clad ceramic substrate is 6.3 μm.

[0025] The input terminal unit and the output terminal unit each include at least two power terminals.

[0026] The structure of a single power terminal is as follows: it includes a welding section for welding with a copper-clad ceramic substrate, and a wiring section for connecting with an external signal line, wherein the wiring section and the welding section are connected via a transition section;

[0027] The welding section is provided with a plurality of notches, thereby increasing the contact area between the welding section and the solder;

[0028] The transition section is provided with at least one through hole and a plurality of V-shaped grooves, and the contact area between the transition section and the injection molded housing is increased by the through hole and the V-shaped grooves;

[0029] A wiring hole is provided on the end surface of the wiring segment, and the wiring hole is used for connecting with an external signal line.

[0030] The notch is a semicircular groove.

[0031] The notch is a round hole.

[0032] The power device module includes a plurality of silicon carbide chips, each of which is bonded to a copper-clad ceramic substrate via a plurality of copper wires;

[0033] It also includes a plurality of gate resistors, each of which corresponds to a gate of the silicon carbide chip one by one, and a single gate resistor is bonded to the gate of the corresponding silicon carbide chip via an aluminum wire.

[0034] A copper sheet is welded on each silicon carbide chip, and the silicon carbide chip is bonded to the copper-clad ceramic substrate through the copper sheet.

[0035] The beneficial effects of the utility model are as follows:

[0036] The utility model has a compact and reasonable structure and is easy to operate. By arranging a base plate and an injection-molded shell that are connected in a heat-sealed manner, air and water vapor in the power device module between the base plate and the injection-molded shell can be removed, and the thermal resistance of the power device module can be reduced, thereby reducing switching losses, improving device efficiency, and effectively improving the performance and quality of the encapsulated silicon carbide power device.

[0037] The utility model also has the following advantages:

[0038] (1) In the present invention, by providing a notch on the power terminal, the contact area between the solder and the power terminal can be increased, the solder creeping ability can be improved, and the bonding strength between the power terminal and the copper-clad ceramic substrate can be improved.

[0039] (2) The slots in the present invention have various forms including round holes and semicircular slots, and the forms are flexible.

[0040] (3) In the present invention, by providing a through hole and a V-shaped groove on the power terminal, the contact area between the injection-molded housing and the power terminal can be increased, thereby improving the bonding force between the injection-molded housing and the power terminal.

[0041] (4) In the present invention, the copper layer on the surface of the copper-clad ceramic substrate is roughened so that its surface roughness reaches 6.3 μm, which can increase the adhesion between the injection-molded shell and the copper-clad ceramic substrate, thereby improving the bonding force between the injection-molded shell and the copper-clad ceramic substrate.

[0042] (5) In the present invention, by providing copper sheets and copper wires and adopting a silver sintering process, the thermal resistance of the silicon carbide chip can be reduced, a higher power density can be achieved, and thus the heat dissipation performance of the silicon carbide power device can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of the utility model.

[0044] Figure 2 It is a schematic diagram of the internal structure of the utility model.

[0045] Figure 3 for Figure 2 Top view of the .

[0046] Figure 4 for Figure 3 A partial enlarged view of point A in the middle.

[0047] Figure 5 The structure of the power terminal in the utility model is shown in FIG. Figure 1 .

[0048] Figure 6 The structure of the power terminal in the utility model is shown in FIG. Figure 2 .

[0049] Figure 7 for Figure 6 Top view of the .

[0050] Among them: 1. Injection molded shell; 2. Bottom plate; 3. Copper-clad ceramic substrate; 4. Signal terminal; 5. Power terminal; 6. Silicon carbide chip; 7. Aluminum wire; 8. Copper wire; 9. Gate resistor; 10. Copper sheet;

[0051] 501, welding section; 502, transition section; 503, wiring section; 504, wiring hole; 505, notch; 5051, semicircular groove; 5052, round hole; 506, V-shaped groove; 507, through hole. DETAILED DESCRIPTION

[0052] The specific implementation of the present utility model is described below in conjunction with the accompanying drawings.

[0053] The structure and functions of the utility model are as follows:

[0054] like Figure 1-Figure 7As shown, an injection molding packaging structure includes a base plate 2, a copper-clad ceramic substrate 3 is welded to the top end surface of the base plate 2, a power device module is welded to the copper-clad ceramic substrate 3, and an injection molding shell 1 is heat-sealed to the top of the base plate 2, and the injection molding shell 1 wraps the power device module; a plurality of signal terminals 4 for controlling signal transmission, an input terminal unit for connecting to an input power supply, and an output terminal unit for outputting output signals are arranged between the base plate 2 and the injection molding shell 1. The injection molding packaging structure of the utility model includes an injection molding shell 1, a base plate 2, a copper-clad ceramic substrate 3, a signal terminal 4, a power terminal 5, and a power device module; wherein,

[0055] like Figure 1 As shown, the injection molded housing 1 and the bottom plate 2 completely surround and cover the copper-clad ceramic substrate 3 and the power device module, thereby protecting the internal circuit of the power device; the ends of the signal terminal 4 and the power terminal 5 are both extended between the injection molded housing 1 and the bottom plate 2, and are electrically connected to the copper-clad ceramic substrate 3;

[0056] The injection molded shell 1 also wraps the copper-clad ceramic substrate 3 ; the injection molded shell 1 wraps the top and sides of the bottom plate 2 , the bottom plate 2 is a square thin plate, and the injection molded shell 1 wraps the top end face and four side end faces of the bottom plate 2 .

[0057] In the utility model, the injection-molded housing 1 and the base plate 2 are connected by heat sealing, that is, the molten injection-molded material is directly covered on the base plate 2 by an injection molding machine (at this time, the copper-clad ceramic substrate 3 and the power device module have been installed on the base plate 2, and the signal terminals 4 and the power terminals 5 have been welded on the copper-clad ceramic substrate 3). The molten injection-molded material completely covers the copper-clad ceramic substrate 3 and the power device module on the base plate 2, and covers part of the signal terminals 4 and part of the power terminals 5. After the molten injection-molded material is cooled, the injection-molded housing 1 is formed, which can remove air and water vapor inside the power device module.

[0058] In addition, in order to prevent the power device module from being damaged by excessive temperature, it is necessary to ensure that the temperature of the injection-molded housing 1 and the base plate 2 is maintained at about 160° C. during the heat-sealing process.

[0059] In order to improve the structural stability of the injection molding packaging structure, in the utility model, the copper-clad ceramic substrate 3 is roughened and the surface roughness of the copper layer on the surface of the copper-clad ceramic substrate 3 is increased by using a laser process, so that the surface roughness of the copper-clad ceramic substrate 3 is 6.3 μm, thereby improving the bonding force between the injection molding shell 1 and the copper-clad ceramic substrate 3.

[0060] like Figure 2-Figure 4As shown, the power device module includes several silicon carbide modules, and a single silicon carbide module includes a silicon carbide chip 6. The collector of the silicon carbide chip 6 is bonded and welded on the copper-clad ceramic substrate 3, and the emitter of the silicon carbide chip 6 is led out through several copper wires 8; it also includes several gate resistors 9, and the gate resistors 9 correspond to the gates of the silicon carbide chip 6 one by one. A single gate resistor 9 is bonded to the gate of the corresponding silicon carbide chip 6 through an aluminum wire 7; a copper sheet 10 for leading out the copper wire 8 is welded on the collector of each silicon carbide chip 6.

[0061] In the present invention, in order to reduce the thermal resistance of the silicon carbide chip 6, the silicon carbide chip 6 and the copper-clad ceramic substrate 3, and the silicon carbide chip 6 and the copper sheet 10 are welded by silver sintering process;

[0062] By using copper wire 8 to bond the silicon carbide chip 6 and the copper-clad ceramic substrate 3, the copper wire 8 has better high temperature resistance; by arranging a copper sheet 10 between the copper wire 8 and the silicon carbide chip 6, the thermal resistance of the silicon carbide chip 6 can be further reduced, so that the silicon carbide power device can achieve a higher power density, thereby improving the heat dissipation performance of the silicon carbide power device.

[0063] The signal terminal 4, the input terminal unit and the output terminal unit are all electrically connected to the power device module through the copper-clad ceramic substrate 3; wherein the signal terminal 4 adopts a pin structure, the input terminal unit includes at least two power terminals 5, and the output terminal unit includes at least one power terminal 5;

[0064] like Figure 5-Figure 7 As shown, the structure of a single power terminal 5 is as follows: it includes a welding section 501 for welding with the copper-clad ceramic substrate 3, and a wiring section 503 for connecting with an external signal line, and the wiring section 503 and the welding section 501 are connected through a transition section 502; a plurality of notches 505 are provided on the welding section 501, thereby increasing the contact area between the welding section 501 and the solder; at least one through hole 507 and a plurality of V-shaped grooves 506 are provided on the transition section 502, and the contact area between the transition section 502 and the injection-molded housing 1 is increased by the through hole 507 and the V-shaped groove 506; a wiring hole 504 is provided on the end surface of the wiring section 503, and the wiring hole 504 is used to connect with an external signal line.

[0065] In the utility model, a single power terminal 5 includes a welding section 501, a transition section 502 and a wiring section 503 which are sequentially connected and arranged; wherein the end surface of the welding section 501 is in contact with the top end surface of the copper-clad ceramic substrate 3, and welding is performed by soldering. By providing a notch 505 on the welding section 501, the contact area between the solder and the power terminal 5 can be increased, the solder creeping ability can be increased, and the bonding force between the power terminal 5 and the copper-clad ceramic substrate 3 can be increased;

[0066] The notch 505 can be a semicircular notch 5051, or a circular hole 5052, and the arrangement is flexible;

[0067] The transition section 502 is used to connect the welding section 501 and the wiring section 503. At the same time, after the packaging is completed, the transition section 502 and the welding section 501 are both located between the injection molded housing 1 and the bottom plate 2, and are wrapped by the injection molded housing 1; by providing a through hole 507 and a V-shaped groove 506 on the end surface of the transition section 502, the contact area between the injection molded housing 1 and the power terminal 5 can be increased, thereby improving the bonding force between the injection molded housing 1 and the power terminal 5;

[0068] The wiring segment 503 is used to connect to an external signal line, and realize the input of a driving signal or the output of an output signal through the external signal line; the wiring is realized by opening a wiring hole 504 on the end surface of the wiring segment 503.

[0069] The working process of the utility model is as follows:

[0070] In one embodiment of the utility model, the power device module is used to convert direct current into alternating current;

[0071] The power device module adopts a half-bridge inverter circuit topology, in which multiple silicon carbide modules are connected in parallel in a single bridge arm to ensure the stability and reliability of the entire circuit;

[0072] like Figure 1 As shown, in one embodiment of the utility model, three power terminals 5 are arranged in the input terminal unit (two of which are used to connect the positive pole of the driving power supply, and the other is used to connect the negative pole of the driving power supply), and one power terminal 5 is arranged in the output terminal unit;

[0073] Select a power terminal 5 for connecting the positive electrode of the driving power supply to connect to the positive electrode of the driving power supply, and select a power terminal 5 for connecting the negative electrode of the driving power supply to connect to the negative electrode of the driving power supply;

[0074] The control system realizes signal transmission with the power device module through the signal terminal 4;

[0075] The driving power supply inputs direct current to the power device module through the input terminal unit, and the control system controls the corresponding silicon carbide chip 6 to conduct through the signal terminal 4, so that the power device module converts direct current into alternating current and outputs it through the output terminal unit.

[0076] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the protection scope of the utility model.

Claims

1. An injection molding packaging structure, characterized in that: It comprises a base plate (2), a copper-clad ceramic substrate (3) is welded to the top end surface of the base plate (2), a power device module is welded to the copper-clad ceramic substrate (3), an injection-molded shell (1) is heat-sealed to the top of the base plate (2), and the injection-molded shell (1) wraps the power device module; A plurality of signal terminals (4) for controlling signal transmission, an input terminal unit for connecting to an input power source, and an output terminal unit for outputting an output signal are arranged between the base plate (2) and the injection molded housing (1).

2. The injection molding packaging structure according to claim 1, characterized in that: The injection-molded housing (1) also wraps the copper-clad ceramic substrate (3).

3. The injection molding packaging structure according to claim 1, characterized in that: The injection molded housing (1) wraps around the top and sides of the base plate (2).

4. The injection molding packaging structure according to claim 1, characterized in that: The surface roughness of the copper-clad ceramic substrate (3) is 6.3 μm.

5. The injection molding packaging structure according to claim 1, characterized in that: The input terminal unit includes at least two power terminals (5), and the output terminal unit includes at least one power terminal (5).

6. The injection molding packaging structure according to claim 5, characterized in that: The structure of a single power terminal (5) is as follows: it comprises a welding section (501) for welding with a copper-clad ceramic substrate (3), and a wiring section (503) for connecting with an external signal line, wherein the wiring section (503) and the welding section (501) are connected via a transition section (502); The welding section (501) is provided with a plurality of notches (505), thereby increasing the contact area between the welding section (501) and the solder; The transition section (502) is provided with at least one through hole (507) and a plurality of V-shaped grooves (506), and the contact area between the transition section (502) and the injection molded housing (1) is increased by the through hole (507) and the V-shaped grooves (506); A wiring hole (504) is provided on the end surface of the wiring segment (503), and the wiring hole (504) is used for connecting to an external signal line.

7. The injection molding packaging structure according to claim 6, characterized in that: The notch (505) is a semicircular groove (5051).

8. The injection molding packaging structure according to claim 6, characterized in that: The notch (505) is a circular hole (5052).

9. The injection molding packaging structure according to claim 1, characterized in that: The power device module comprises a plurality of silicon carbide modules, wherein a single silicon carbide module comprises a silicon carbide chip (6), the collector of the silicon carbide chip (6) is bonded and welded to a copper-clad ceramic substrate (3), and the emitter of the silicon carbide chip (6) is led out through a plurality of copper wires (8); It also includes a plurality of gate resistors (9), wherein the gate resistors (9) correspond one-to-one to the gates of the silicon carbide chips (6), and a single gate resistor (9) is bonded to the gate of the corresponding silicon carbide chip (6) via an aluminum wire (7).

10. The injection molding packaging structure according to claim 9, characterized in that: A copper sheet (10) for leading out a copper wire (8) is welded on the collector of each silicon carbide chip (6).

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