Power electronic packaging module

Abstract

The utility model provides a power electronic packaging module. The power electronic packaging module comprises a substrate, a wafer, a plurality of terminals and a packaging shell, the substrate (1) is located in the packaging shell (9), and the heat conductivity coefficient of the substrate (1) is larger than 100 W / (m * K); the front surface of the substrate (1) is provided with an etched circuit pattern layer (8), the wafer (2) is assembled on the front surface of the substrate (1) through a binder, one end of each terminal (3) is welded on the front surface of the substrate (1) in a manner that the side surface is flatly attached, and the other end of each terminal (3) is folded towards the direction far away from the front surface of the substrate (1) and extends to the outside of the packaging shell (9) to form a pin; the pins comprise a plurality of power pins (4) and a plurality of signal pins (5). The number of the terminals and the material of the substrate can be varied and flexibly selected and matched according to different application functions, the packaging module has efficient and safe heat dissipation and insulation resistance, the manufacturing process of the packaging module is simplified, the production efficiency is improved, and the packaging module is suitable for different power application scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of packaging of power electronic power packaging modules, in particular to a power electronic packaging module with efficient heat dissipation. Background Art

[0002] Power integration refers to the use of an integrated method to package the power devices that constitute the power electronic system with the corresponding drive, protection and control circuits, as well as auxiliary power supplies, sensors, passive components, etc. into an independent whole in the form of a combination, making it an integrated device with relatively complete functions and certain versatility. Using integrated devices, power electronic devices and systems with different performance requirements and application purposes can be conveniently and flexibly constructed.

[0003] In order to adapt to the different application requirements of the semiconductor industry, the existing integrated devices are divided into consumer, industrial, military and automotive categories according to the application scenarios and circuit selection. At present, integrated devices are generally suitable for specific occasions. The power electronics system requires that power semiconductor devices must work in a wide power and frequency range and have only a single package type, which makes the application of integrated devices inflexible. Therefore, there is an urgent need for an integrated package module with efficient heat dissipation, wide adaptability, diversity and flexible functional applications. Utility Model Content

[0004] This utility model patent provides the society with a module package that meets the design standards, has excellent heat dissipation performance and flexible and diverse circuit function applications, while integrating heat dissipation and anti-insulation applications. By designing the assembly terminals and substrate, it ensures that the heat generated inside the device can be effectively released from the package body, avoiding the sudden temperature rise of the chip in the package body during continuous operation of the device and the untimely heat dissipation leading to performance degradation or burning, and allows the heat to be dissipated in time and safely around the heating equipment or environment of the whole machine. The functional application is flexible and adapts to the efficient insulation and heat dissipation needs of different environments.

[0005] In order to solve the above-mentioned problems, the preferred solution of the utility model is a power electronic packaging module with efficient heat dissipation, which module includes a substrate, a wafer, a plurality of terminals and a packaging shell; the substrate is located in the packaging shell and has a thermal conductivity greater than 100W / (m*K); the front side of the substrate has an etched circuit layer, the wafer is assembled on the front side of the substrate by an adhesive, one end of each of the terminals is welded to the front side of the substrate with a side surface flatly attached, and the other end is folded away from the front side of the substrate and extends to the outside of the packaging shell to form a pin; the pin includes a plurality of power pins and a plurality of signal pins.

[0006] Furthermore, the plurality of terminals are one or both of surface mount welding terminals and direct plug-in pin terminals.

[0007] Furthermore, the terminal is a mounted welding terminal, and its end exposed outside the packaging shell is a reverse bending portion, and the outer edge of the end of the reverse bending portion is provided with a half-etched groove, the depth of the half-etched groove is half of the thickness of the terminal, and the width is consistent with the width of the terminal.

[0008] Furthermore, the plurality of terminals are formed with a plurality of the power pins and a plurality of the signal pins, and the function pins and the signal pins are respectively arranged in a row on two sides of the packaging shell.

[0009] Furthermore, the terminal is a sheet metal stamping made of a conductive metal material, and the surface of the terminal has an anti-oxidation coating.

[0010] Furthermore, the substrate is a copper-clad ceramic substrate, with copper foil on both the front and back sides. The copper foil on the front side forms the etched circuit layer, and the copper foil on the back side is a planar heat-dissipating copper foil. A plurality of stress release holes are provided around the planar heat-dissipating copper foil. The copper-clad ceramic substrate has a ceramic layer in the middle, and the area of ​​the ceramic layer is greater than the area of ​​the copper foil on both sides.

[0011] Furthermore, the outer layer of the planar heat dissipating copper foil on the back side of the substrate is also plated with an anti-oxidation metal film.

[0012] Furthermore, the substrate is an insulating substrate, which includes a metal substrate and an insulating layer located between the metal substrate and the etching circuit layer, the thickness of the etching circuit layer is half of the insulating layer, the metal substrate is an aluminum plate or a copper plate, the area of ​​the insulating layer and the metal substrate is consistent, and the insulating substrate is embedded in the packaging shell to form a fully encapsulated module.

[0013] Furthermore, the power pin and the signal pin have the same thickness, and the power pin has a width greater than that of the signal pin.

[0014] Furthermore, the packaging shell is in the shape of a cuboid made of epoxy resin, with a parting line on the cuboid, and the four sides of the cuboid have 5-10° draft angles, which extend from the parting line to the top or bottom of the packaging shell.

[0015] Compared with the prior art, the beneficial effects and advantages of the power electronic packaging module provided by the utility model are: the substrate and the terminal are connected together through a reasonable design, the substrate is used as a bearing base, and has an efficient accommodating and building space, the wafer is connected to the substrate through binding wires, and the internal circuit function is then led out by the terminal, the number of terminals and the substrate material can be diversified and flexibly selected according to different application functions, and it has efficient and safe heat dissipation and anti-insulation performance, and the manufacturing process of the packaging module is streamlined to improve production efficiency. In addition, the internal integrated power system constructed is not only suitable for automotive electronics and switching power supplies, but is also more suitable for different application scenarios than a single device structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0017] Figure 1 It is a structural diagram of a power electronic packaging module of the first embodiment;

[0018] Figure 2 for Figure 1 An internal structural diagram of a power electronic package module of the illustrated embodiment;

[0019] Figure 3 for Figure 2 A structural diagram of the base plate in the internal structure shown;

[0020] Figure 4 To contain Figure 3 The structural diagram of the power electronic packaging module of the substrate shown is a semi-encapsulated type;

[0021] Figure 5 for Figure 1 A structural diagram of another substrate of the power electronic packaging module of the illustrated embodiment;

[0022] Figure 6 To contain Figure 5 The structure diagram of the power electronic packaging module of the substrate shown is a fully encapsulated type;

[0023] Figure 7 is a structural diagram of a power electronic packaging module according to a second embodiment;

[0024] Figure 8 for Figure 7 A structural diagram of the internal substrate of the illustrated embodiment;

[0025] Fig. 9 is a structural diagram of a power electronic packaging module according to a third embodiment;

[0026] Fig.10 is a structural diagram of a power electronic packaging module according to a fourth embodiment;

[0027] Fig.11 is a structural diagram of a power electronic packaging module according to a fifth embodiment;

[0028] Fig.12 for Fig.11 Another view of the power electronics package module shown. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments 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 present invention, rather than all of them. Based on the embodiments in 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.

[0030] like Figures 1 to 6 The schematic diagram of the structure of a power electronic packaging module with 8 pins of the first embodiment is disclosed. The module includes a substrate 1, a wafer 2, a terminal 3 and a packaging shell 9; the terminals 3 are distributed in 8 numbers, and the terminals 3 are divided into power pins 4 and signal pins 5 according to the functional type, and can be assembled into either a surface mount welding terminal 6 or a direct plug-in pin terminal 7 according to the application type. Figures 1 to 6 In the embodiment shown, the soldering terminal 6 is mounted. The substrate 1 is embedded in the package shell 9, one end of the terminal 3 is soldered on the substrate 1, and the other end extends out of the package shell 9 to form a pin, such as a power pin 4 or a signal pin 5. The front of the substrate 1 is an etched circuit layer 8, and the wafer 2 is assembled on the front of the substrate 1 by solder paste adhesive.

[0031] The terminal 3 is flat, and the side surface of one end thereof is flatly attached to the front surface of the substrate 1 near the edge of the substrate 1 and welded and fixed, and the part behind the flatly attached welded part is folded upwards to the substrate 1, so that the other end of the terminal 3 extends away from the front surface of the substrate 1 until it is exposed to the outside of the packaging shell 9 to form a pin for assembly.

[0032] The pins formed by the eight terminals in this embodiment include three power pins 4 and five signal pins 5, and the power pins 4 are located on one side of the package shell and are evenly spaced, and the signal pins 5 are located on the other side of the package shell. Figure 1 , 2 In the embodiment shown, one power pin 4 is distributed in the middle of four signal pins 5. In this embodiment, the thickness of the power pin 4 and the signal pin 5 are both 0.5 mm. When the terminal 3 is a surface mounted welding terminal 6, the width of the power pin 4 is greater than the width of the signal pin 5, and the width of the power pin 4 is 2 mm, and the width of the signal pin 5 is 1 mm.

[0033] like Figure 1-6As shown, when the terminal 3 is a mounted welding terminal 6, the power pin 4 and the signal pin 5 exposed outside the packaging shell 9 are both reverse bending parts, and the ends of the power pin 4 and the signal pin 5 have a half-etched groove 10. The depth of the half-etched groove 10 is half of the thickness of the terminal 3 0.5 mm, and the overall width is consistent with the width of the terminal 3.

[0034] Terminal 3 is a sheet metal stamping part formed by stamping, and is made of copper material with excellent thermal and electrical conductivity. In order to prevent the copper material from coming into contact with the external environment and causing oxidation, the surface is nickel-plated in advance during stamping, or the terminal 3 is tin-plated during the surface electroplating process of the finished packaging module, thereby forming an anti-oxidation coating.

[0035] The substrate 1 is preferably made of a material with high thermal conductivity, for example, the thermal conductivity should be greater than 100 W / (m*K). Figures 2 to 4 As shown, the material of the substrate 1 is a copper-clad ceramic substrate 11, and the ceramic substrate used as the substrate is an aluminum nitride substrate, and its thermal conductivity is 200W / (m*K). The substrate 1 is located at the top upper position inside the packaging shell 9, and its front and back sides are both etched copper foils, and the front and back areas are consistent in size. The power pins 4 and the signal pins 5 are connected to the etched circuit layer 8 of the front copper foil, and the copper foil on the back is a planar heat dissipation copper foil 13, surrounded by 56 stress release holes 14. The planar heat dissipation copper foil 13 is exposed on the top of the packaging shell 9, so that the copper-clad ceramic substrate 11 is packaged to form a semi-encapsulated module, with a ceramic layer 15 in the middle, and the area of ​​the ceramic layer must be larger than the area of ​​the copper foil on both sides. After packaging, Figure 4 shown.

[0036] To prevent oxidation contamination, nickel can be plated on the planar heat dissipation copper foil 13 in advance to form an anti-oxidation metal film. If nickel plating is not performed, copper protective agent can be added during the electroplating process on the surface of the terminal 3 of the packaging module to prevent oxidation contamination.

[0037] If the substrate 1 is made of an insulating substrate 12 of other materials, such as a copper substrate with better thermal conductivity in this embodiment, the thermal conductivity coefficient can reach 400W / (m*K), then the structure is as follows Figure 5 and Figure 6 As shown, the top layer of the etched circuit layer 8 is covered with a solder resist layer, the middle layer is an insulating layer 16, the thickness of the etched circuit layer 8 is half of the insulating layer 16, the bottom layer is a copper plate 17 with excellent heat dissipation performance, and the thickness of the bottom layer is 15-20 times the thickness of the insulating layer 16. The area of ​​the etched circuit layer 8 is slightly smaller than the overall area of ​​the insulating layer 16, and the overall area of ​​the insulating layer 16 and the bottom layer are consistent. The copper substrate is embedded in the packaging shell 9 without being exposed to form a fully encapsulated module.

[0038] In the fully encapsulated module, the packaging shell 9 is in the shape of a rectangular parallelepiped with a parting line on the rectangular parallelepiped. The plastic sealing body at the upper end of the parting line is larger than the plastic sealing body at the lower end of the parting line. The four sides of the rectangular parallelepiped have 5-10° draft angles, which extend from the parting line to the top and bottom of the packaging shell 9. Four circular ejector pin prints 18 and one rectangular ejector pin print 19 are distributed at the bottom of the packaging shell 9 for easy demolding. The entire packaging shell 9 is formed by wrapping with epoxy resin.

[0039] The wafer 1 and the terminal 3 are assembled and welded on the substrate 1 by means of an adhesive, the adhesive being a solder paste solder infrared reflow sintering assembly, the assembly position being an etching circuit layer 8 on the top layer of the substrate 1, the electrodes of the wafer 1 are connected to the substrate 1 by aluminum binding wires, and the internal circuit functions are then led out by welding the substrate 1 and the terminal 3.

[0040] According to the layout of the etching circuit 8 on the top layer of the substrate 1, the wafer 2 can be constructed as a half-bridge module circuit or a full-bridge module circuit application. According to the thermal conductivity and circuit application of the substrate 1 type, the type of wafer 2 can be selected from three types of silicon-based wafers, silicon carbide wafers and gallium nitride wafers for circuit assembly applications.

[0041] Figure 7 The second embodiment shown is a packaging structure diagram of a power electronic module with a direct plug-in pin terminal. Figures 1 to 6 The features are the same as above, the only difference is that Figure 7 The 8 terminals in the module are straight-in pin terminals. Figures 1 to 6 The embodiment shown is a surface mounted solder terminal. Figure 8 The internal structure of this embodiment can clearly show the structure of the straight-plug pin terminal, in which the extension direction of the pin is perpendicular to the surface of the substrate.

[0042] Fig. 9 The third embodiment shown is a power electronic module with 7 pins, all of which are mounted solder terminals. As shown in the figure, one side has 3 power pins 4 arranged at equal intervals, and the other side has 4 signal pins 5.

[0043] Fig.10 The fourth embodiment shown is a 9-pin power electronic module. It can be seen that the width of the power pin 4 can be several times greater than the width of the signal pin 5 .

[0044] Fig.11 , 12 The fifth embodiment shown is a schematic diagram of a power electronic module composed of 10-pin mounting solder terminals, and the power pins and signal pins can be mixedly arranged on the same side.

[0045] Based on this, module structures with more or fewer pins can be derived, which will not be elaborated here.

[0046] The specific steps of the manufacturing method of the power electronic packaging module are described below:

[0047] A1. Place the five substrates 1 at equal intervals in the cavity of a special jig and fix them. Then, place the special jig with the five substrates 1 in a printing machine with a pre-opened steel mesh window for solder coating, so that the solder coating is evenly distributed at various positions on the substrate 1 that need to be assembled;

[0048] A2. Place the solder-coated substrate 1 into a wafer loading machine, pick up the wafer 2 for die bonding, and pick up and place the wafer 2 according to the etching circuit layer 8 on the top layer of the substrate 1 to complete the wafer loading operation;

[0049] A3. Place the lead frame consisting of 8 terminals 3 into the lead frame carrier, and use the pins under the carrier and the pin holes on the special fixture to position and assemble, so that the terminals 3 are in contact with the solder applied on the substrate 1, and the terminals 3 and the substrate 1 are fixedly connected after infrared reflow;

[0050] A4. After assembly, the terminal 3 - substrate 1 is ultrasonically cleaned and plasma cleaned to remove the residue on the substrate surface. The appearance dimensions and reliability tests are performed using inspection and measurement instruments. Qualified products enter the next step of wire bonding operation.

[0051] A5. Electrically bond the substrate 1 and the wafer 2 with aluminum wires in sequence, bond the surface electrodes of the wafer 2 and the surface of the substrate 1, and then use the connection between the substrate 1 and the terminal 3 to lead out the circuit function;

[0052] A6. After completing the electrical binding, the semi-finished module will flow to the molding encapsulation, electroplating surface treatment and rib cutting and forming processes in sequence. Finally, the packaged product will pass the test and print mark, and the qualified products will be packaged and shipped out.

[0053] The beneficial effects of a power electronic packaging module with efficient heat dissipation provided by an embodiment of the utility model are: the substrate is selected according to the different adaptation application scenarios and circuit power dissipation, the internal circuit function is built, and the number of terminals should be brought out according to design requirements. The pins can be increased and adjusted according to needs, and the substrate production layout can match different wafer types, such as IGBT, MOS, FRD, etc., thereby satisfying the semiconductor industry's flexible and diversified selection of power device packaging modules, and is suitable for realizing that the packaging module has excellent heat dissipation and insulation performance in the application of complete systems such as automotive electronics and switching power supplies.

[0054] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0055] Obviously, the above embodiments of the present invention are merely examples used to clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description, and it is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A power electronic packaging module, characterized in that: The module comprises a substrate (1), a wafer (2), a plurality of terminals (3) and a packaging shell (9); the substrate (1) is located in the packaging shell (9) and has a thermal conductivity greater than 100 W / (m*K); the front side of the substrate (1) has an etched circuit layer (8); the wafer (2) is assembled on the front side of the substrate (1) by means of an adhesive; one end of each terminal (3) is welded flatly on the front side of the substrate (1) with a side surface, and the other end is folded away from the front side of the substrate (1) and extends to the outside of the packaging shell (9) to form a pin; the pin comprises a plurality of power pins (4) and a plurality of signal pins (5).

2. The power electronic packaging module according to claim 1, characterized in that: The plurality of terminals (3) are one or both of surface mounted welding terminals (6) and direct plug-in pin terminals (7).

3. The power electronic packaging module according to claim 2, characterized in that: The terminal (3) is a mounted welding terminal (6), and one end portion thereof exposed outside the packaging shell (9) is a reverse bending portion, and a semi-etched groove (10) is provided at the outer edge of the end of the reverse bending portion. The depth of the semi-etched groove (10) is half the thickness of the terminal (3), and the width is consistent with the width of the terminal (3).

4. The power electronic packaging module according to claim 1, characterized in that: The plurality of terminals (3) are formed with a plurality of power pins (4) and a plurality of signal pins (5), and the power pins (4) and the signal pins (5) are respectively located in a row on two sides of the packaging shell (9).

5. The power electronic packaging module according to claim 1, characterized in that: The terminal (3) is a sheet metal stamping part made of a conductive metal material, and the surface of the terminal has an anti-oxidation coating.

6. The power electronic packaging module according to claim 1, characterized in that: The substrate (1) is a copper-clad ceramic substrate (11), the front and back sides of which are both copper foils, the copper foil on the front side forms the etched circuit layer (8), the copper foil on the back side is a planar heat dissipation copper foil (13), a plurality of stress release holes (14) are provided around the planar heat dissipation copper foil (13), a ceramic layer (15) is provided in the middle of the copper-clad ceramic substrate (11), and the area of ​​the ceramic layer (15) is larger than the area of ​​the copper foils on both sides.

7. The power electronic packaging module according to claim 6, characterized in that: The outer layer of the planar heat dissipation copper foil (13) on the back side of the substrate (1) is also plated with an anti-oxidation metal film.

8. The power electronic packaging module according to claim 1, characterized in that: The substrate (1) is an insulating substrate (12), the insulating substrate (12) comprising a metal substrate and an insulating layer (16) located between the metal substrate and the etching circuit layer (8), the thickness of the etching circuit layer (8) is half of the insulating layer (16), the metal substrate is an aluminum plate or a copper plate (17), the insulating layer (16) and the metal substrate have the same area, and the insulating substrate (12) is embedded in the packaging shell (9) to form a fully encapsulated module.

9. The power electronic packaging module according to claim 1, characterized in that: The power pin (4) and the signal pin (5) have the same thickness, and the power pin (4) has a width greater than that of the signal pin (5).

10. The power electronic packaging module according to claim 1, characterized in that: The packaging shell (9) is in the shape of a cuboid made of epoxy resin, with a parting line on the cuboid, and the four sides of the cuboid have a draft angle of 5 to 10 degrees, and the draft angles extend from the parting line to the top or bottom of the packaging shell (9).

Images