Power module capable of withdrawing needles from front side

Abstract

The invention discloses a power module with pins withdrawn from the front side, and belongs to the technical field of module packaging. Comprising a metalized ceramic substrate; the metal piece comprises a flat welding bottom surface and a flat welding surface, and the welding bottom surface of the metal piece is connected with the emitting electrode of the metalized ceramic substrate through ultrasonic welding; and the PIN is vertically arranged on the welding surface of the metal piece through ultrasonic welding. The technical scheme has the beneficial effects that the welding strength and flatness are ensured, the product layout space is saved, and the yield and the product performance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of module packaging, and in particular to a power module. Background Art

[0002] Traditional leadframe pin-out methods and solder paste soldering copper pillar processes are widely used in semiconductor power modules, but with increasingly stringent customer requirements, these methods can no longer meet the diverse project requirements. Currently, PIN pin welding mainly uses solder paste soldering technology. The traditional leadframe pin-out expansion space occupies a large space. At the same time, the surface flatness of the traditional solder paste soldering copper pillar is poor, and the welding strength is relatively low, which easily leads to low product yield. Summary of the invention

[0003] The purpose of the present invention is to provide a power module with front-side pin outlet to solve the above technical problems;

[0004] A power module with front-side pins, comprising:

[0005] Metallized ceramic substrate;

[0006] A metal piece, the metal piece comprising a flat welding bottom surface and a flat welding surface, the welding bottom surface of the metal piece being connected to the emitter of the metallized ceramic substrate by ultrasonic welding;

[0007] A PIN needle is vertically arranged on the welding surface of the metal part by ultrasonic welding.

[0008] Preferably, the PIN needle is cylindrical and is made of copper material.

[0009] Preferably, the metal piece is cylindrical, made of copper material, and has a width of 2 mm to 6 mm.

[0010] Preferably, a power terminal is also connected to the emitter of the metallized ceramic substrate by ultrasonic welding.

[0011] Preferably, a semiconductor device is further provided on the emitter of the metallized ceramic substrate, and solder is provided between the semiconductor device and the emitter of the metallized ceramic substrate.

[0012] Preferably, the semiconductor device comprises at least one power chip and one diode, the semiconductor device is connected to the emitter of the metallized ceramic substrate via a metal bonding wire, and the semiconductor devices are connected to each other via the metal bonding wire.

[0013] Preferably, it further comprises a heat dissipation substrate, which is arranged on the back side of the metallized ceramic substrate, and the area of ​​the heat dissipation substrate is larger than the area of ​​the power module.

[0014] Preferably, it further comprises a shell, wherein the shell is arranged on the heat dissipation substrate, or the shell is connected to the outer side of the heat dissipation substrate.

[0015] Preferably, the housing is connected to the heat dissipation substrate to form an accommodation space, in which the metallized ceramic substrate, the metal piece and the PIN needle are arranged, and one end of the PIN needle extends vertically upward out of the housing.

[0016] Preferably, the solder is provided between the heat dissipation substrate and the metallized ceramic substrate, and the solder includes at least one of tin-lead, tin-silver, tin-silver-copper, and lead-tin-silver.

[0017] The beneficial effects of the present invention are: ensuring the strength and flatness of welding, saving product layout space, and improving the yield rate and product performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention in one embodiment;

[0019] Figure 2 is a schematic structural diagram of the present invention in another embodiment;

[0020] Figure 3 is a top view of another embodiment of the present invention;

[0021] Figure 4 is a side view of the present invention in another embodiment;

[0022] Figure 5 It is a schematic diagram of the present invention arranged in parallel on a heat dissipation substrate;

[0023] Figure 6 is a schematic diagram of an ultrasonic welding device used in the present invention;

[0024] Figure 7 is a schematic diagram of a welding head used in the present invention; Figure 8 It is a flow chart of the injection molding packaging process of the present invention.

[0025] In the attached figure: 1. Metallized ceramic substrate; 11. Emitter; 2. Metal parts; 3. PIN needle; 4. Power terminal; 5. Semiconductor device; 6. Heat dissipation substrate; 7. Housing; 8. Solder; 9. Ultrasonic welding equipment; 91. Welding head; 92. Vacuum adsorption hole; 10. Metal bonding wire. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0028] 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.

[0029] A power module with pins coming out from the front, such as Figure 1 As shown, including

[0030] Metallized ceramic substrate 1;

[0031] A metal member 2, the metal member 2 comprises a flat welding bottom surface and a flat welding surface, and the welding bottom surface of the metal member 2 is connected to the emitter 11 of the metallized ceramic substrate 1 by ultrasonic welding;

[0032] The PIN needle 3 is vertically arranged on the welding surface of the metal part 2 by ultrasonic welding.

[0033] Specifically, the present invention provides a power module with front-side pins, which connects a metal part 2 and a PIN needle 3 by ultrasonic welding, thereby ensuring the strength and flatness of welding, saving product layout space, and improving the yield rate and product performance.

[0034] Ultrasonic welding is a direct welding between metals. The welding bottom surface of metal part 2 is welded to metallized ceramic substrate 1, and the welding surface of metal part 2 is welded to PIN needle 3. The surface of the metal is flat, which can ensure the strength and flatness of the welding. Compared with the solder paste reflow method, the electrical conductivity and thermal conductivity are significantly improved; the high-frequency vibration wave of the ultrasonic head vibration part is transmitted to the metal part 2 and the metallized ceramic substrate 1, and the PIN needle 3 and the metal part 2.

[0035] Under pressure, the two metal surfaces are rubbed to form a fusion between the molecular layers, which is directly manifested as the metal being squeezed, deformed and welded together. Therefore, the welding bonding force is higher than the connection strength of the solder paste reflow method, and the deformation is controllable and stable, which improves the reliability of the module.

[0036] In a preferred embodiment, the PIN needle 3 is cylindrical and is made of copper.

[0037] Specifically, the PIN needle 3 includes a needle body and a base, and the cross-sectional area of ​​the base is larger than the cross-sectional area of ​​the needle body. The base area provides a wider contact surface, which enhances the connection quality of the welding point. During the ultrasonic welding process, the larger the contact surface, the more significant the friction heat and relative movement generated, thereby promoting the molecular layer fusion between the metals and increasing the reliability of the connection.

[0038] PIN 3 can be integrated or plug-in. The plug-in design makes the module more convenient to install and maintain. Users can easily replace or repair PIN 3 without replacing the entire module, which can greatly reduce maintenance costs and time.

[0039] The integrated PIN needle 3 can provide higher structural strength and reliability.

[0040] Reference Figure 6 , Figure 7 The ultrasonic welding device 9 grabs the PIN pin 3 through the welding head 91 and accurately places the PIN pin 3 on the welding surface of the specified metal part 2. When the welding mode is set to the deformation mode, the welding head 91 is used to weld the PIN pin 3 until the deformation of the welding base of the PIN pin 3 reaches the preset deformation amount and then stops welding.

[0041] In a preferred embodiment, the metal member 2 is cylindrical, made of copper, and has a width of 2 mm to 6 mm.

[0042] Specifically, the metal piece 2 and the PIN needle 3 are made of the same material and can be welded together better. The metal piece 2 can be a copper column. The cylindrical metal piece 2 is easy to process and can be made by stamping technology or cutting technology.

[0043] Through stamping or cutting technology, the required shape can be produced quickly and accurately, reducing production time and cost, making the subsequent assembly process more convenient and effectively improving production efficiency.

[0044] By using stamping or cutting technology to manufacture the metal part 2, the waste of raw materials can be reduced and the production process can be optimized. The simplicity of the cylindrical design also makes the investment in molds and equipment relatively low, further reducing the overall production cost.

[0045] The cylindrical metal part 2 enables it to better dock with other components (such as PIN needle 3) during assembly, provides a larger contact area, and is convenient for welding. At the same time, the positioning of the metal part 2 in the package body is also simpler, which helps to ensure the stability and consistency of the overall structure.

[0046] The width of the copper column is specifically 3mm to 5mm, which enables it to adapt to electronic components of different sizes and power requirements. This adaptability allows manufacturers to quickly adjust production lines according to the needs of different products to meet the changing needs of the market.

[0047] On the other hand, it provides good mechanical strength, making it difficult to bend or deform during use, thereby ensuring the stability and reliability of the metal part 2.

[0048] The ultrasonic welding equipment 9 grabs the metal part 2 through the welding head 91, places the metal part 2 on the set position of the metallized ceramic substrate 1, and sets the ultrasonic welding equipment 9 to the deformation mode. The welding head 91 of the ultrasonic welding equipment 9 is used to weld the welding bottom surface of the metal part 2 to be welded and the emitter 11, and the welding is stopped when the deformation of the welding bottom surface of the metal part 2 reaches the preset deformation amount.

[0049] The metallized ceramic substrate 1, the metal part 2, and the PIN needle 3 are all made of copper. Copper is an excellent conductive material that can effectively reduce the resistance in electronic components and ensure fast signal transmission. When the surface of the metallized ceramic substrate 1 is coated with a conductive copper layer, the conductivity of the substrate can be further improved, which is suitable for high-frequency and high-power applications.

[0050] Copper has excellent thermal conductivity, which helps to effectively dissipate heat, reduce heat build-up in electronic devices, and extend the service life of components.

[0051] The metallized ceramic substrate 1 can withstand high temperatures and has good thermal stability, and can maintain its performance in a high temperature environment. The metallized ceramic substrate 1 provides good mechanical strength, can maintain shape and performance under high load conditions, and prevent damage.

[0052] Compared with the solder paste reflow method, the electrical conductivity and thermal conductivity are significantly improved. The high-frequency vibration wave of the ultrasonic head vibration part is transmitted to the metal part 2 and the metallized ceramic substrate 1, the PIN needle 3 and the metal part 2. Under pressure, the two metal surfaces are rubbed to form a fusion between the molecular layers. Therefore, the welding bonding force is higher than the solder paste reflow method, and the deformation is controllable and stable, which improves the reliability of the module.

[0053] In a preferred embodiment, referring to Figure 2 , Figure 3 The power terminal 4 is also connected to the emitter 11 of the metallized ceramic substrate 1 by ultrasonic welding.

[0054] Specifically, the ultrasonic welding device 9 welds the bottom of the power terminal 4 to the emitter 11 of the metallized ceramic substrate 1 through the welding head 91. It is responsible for transmitting current, enabling the module to be effectively electrically connected to other electronic components and ensuring the smooth flow of current.

[0055] In a preferred embodiment, the semiconductor device 5 includes at least one power chip and one diode. The semiconductor device 5 is connected to the emitter 11 of the metallized ceramic substrate 1 via a metal bonding wire 10 , and the semiconductor devices 5 are connected to each other via metal bonding wires 10 .

[0056] Specifically, at least one semiconductor device 5 is disposed on the conductive copper layer of the metallized ceramic substrate 1 and is soldered on the conductive copper layer.

[0057] The semiconductor device 5 comprises at least one power chip and one diode. Metal bonding wires are used to realize electrical connection between the bonding surface of the power chip and the bonding surface of the diode, between the power chip and the corresponding metallized ceramic substrate 1, and between the diode and the corresponding metallized ceramic substrate 1.

[0058] Metal bonding wires are made of aluminum or copper. Aluminum is cheaper than copper, so using aluminum can reduce overall costs. Aluminum has a low density, which reduces the overall weight of the device, and a low melting point, which allows for good bonding during the welding process. In addition, aluminum has good oxidation resistance, which can prevent the degradation of the bonding joint to a certain extent.

[0059] Copper has a much higher electrical conductivity than aluminum, which can effectively reduce power consumption and heat generation in applications with high currents. Copper has a high thermal conductivity, which can effectively conduct heat, help dissipate heat, and improve the performance and reliability of semiconductor devices.

[0060] Copper is generally mechanically stronger than aluminum, can better withstand external stresses, and is suitable for high-power applications. Copper is also corrosion-resistant and durable when properly processed.

[0061] In a preferred embodiment, a heat dissipation substrate 6 is further included. The heat dissipation substrate 6 is arranged on the back side of the metallized ceramic substrate 1 , and the area of ​​the heat dissipation substrate 6 is larger than the area of ​​the power module.

[0062] Specifically, refer to Figure 4 , Figure 5 Three half-bridge modules (power modules) are arranged on the heat dissipation substrate 6. The area of ​​the heat dissipation substrate 6 is larger than that of the power module, which can more effectively absorb and dissipate the heat generated by the power module, thereby reducing the operating temperature of the module and extending its service life. The large area of ​​the heat dissipation substrate 6 helps to evenly distribute the heat, prevent local overheating, and improve the thermal stability of the entire system.

[0063] In a preferred embodiment, it further comprises a housing 7, which is disposed on the heat dissipation substrate 6, or the housing 7 is connected to the outer side of the heat dissipation substrate 6;

[0064] The housing 7 is connected to the heat dissipation substrate 6 to form an accommodation space. The accommodation space is provided with a metallized ceramic substrate 1 , a metal piece 2 and a PIN needle 3 . One end of the PIN needle 3 extends vertically upward out of the housing 7 .

[0065] Specifically, the housing 7 is formed by injection molding, referring to Figure 4 The housing 7 is disposed on the heat dissipation substrate 6, and the housing 7 is connected to the heat dissipation substrate 6 to form an accommodating space, and the accommodating space is provided with:

[0066] Metallized ceramic substrate 1, metal part 2 and PIN pin 3, one end of PIN pin 3 vertically extends upward out of housing 7 to form an external connection part.

[0067] The emitter 11 of the metallized ceramic substrate 1 is also welded with a power terminal 4, which is responsible for transmitting current so that the module can be effectively electrically connected to other electronic components to ensure smooth flow of current.

[0068] Reference Figure 1 The outer shell 7 is connected to the outer side of the heat dissipation substrate 6, and the heat dissipation substrate 6, the metallized ceramic substrate 1, the metal part 2 and the PIN pin 3 are encapsulated inside the outer shell 7, and one end of the PIN pin 3 vertically extends upward from the outer shell 7 to form an external connection part. This can overcome the problem that the terminal pins of the traditional plastic-encapsulated power module are encapsulated on the side of the outer shell 7 and the PIN pin 3 cannot be led out from the top of the module.

[0069] Different connection methods can encapsulate the metallized ceramic substrate 1, the metal part 2, the PIN needle 3, and the semiconductor device 5 inside the housing 7 to ensure the safety and sealing of the power module.

[0070] One end of the PIN needle 3 extends vertically upward out of the housing 7, realizing a packaging structure in which the plastic-encapsulated power module leads to external electrical connection components from the top of the module.

[0071] The metal part 2 and the PIN needle 3 are both welded by ultrasonic welding, which eliminates the participation of the reflow process, reduces the failure factors in the reflow process, improves the welding bonding strength of the PIN needle 3, optimizes the process, and improves the reliability of the module.

[0072] In a preferred embodiment, a semiconductor device 5 is further provided on the emitter 11 of the metallized ceramic substrate 1, and a solder 8 is provided between the semiconductor device 5 and the emitter 11 of the metallized ceramic substrate 1;

[0073] A solder 8 is provided between the heat dissipation substrate 6 and the metallized ceramic substrate 1 , and the solder 8 includes at least one of tin-lead, tin-silver, tin-silver-copper, and lead-tin-silver.

[0074] Specifically, the solder 8 is welded and connected using one of Sn-containing soldering materials of SnPb, SnAg, SnAgCu, and PbSnAg, and the maximum welding temperature is controlled within the range of 350° C. to 400° C.

[0075] The tin in the solder 8 has good electrical conductivity and can form a low-impedance electrical connection. In particular, in a molten state, metals such as tin and silver can flow quickly to fill tiny gaps and reduce contact resistance.

[0076] The thermal conductivity of metals such as tin and silver is relatively high, and the interface formed by the solder 8 after connection can effectively conduct heat, thereby reducing the operating temperature of the device and avoiding performance degradation due to overheating.

[0077] The metal connection formed by the solder 8 after cooling and solidification has certain toughness and strength, especially the tin-lead alloy, which has good ductility at high temperature and can effectively withstand the stress caused by thermal expansion.

[0078] The maximum welding temperature is controlled within the range of 350℃~400℃, which can effectively reduce the thermal stress generated during welding. It can make the material smoother during welding and cooling, reduce stress concentration and prevent mechanical failure.

[0079] Ultrasonic welding is a welding technology used for direct connection between metals. In this process, the welding bottom surface of the metal part 2 is welded to the metallized ceramic substrate 1, and the welding surface of the metal part 2 is welded to the PIN needle 3. Since the metal surface to be welded is flat, the strength and flatness of the welding are ensured.

[0080] Compared with the traditional solder paste reflow soldering method, this soldering technology effectively transfers energy to the metal part 2, the metallized ceramic substrate 1, and the PIN needle 3 through the high-frequency vibration waves generated by the ultrasonic head. Under pressure, friction is generated between the two metal surfaces, thereby forming fusion between the molecular layers. This is directly manifested as extrusion deformation of the metal, making the soldering more solid.

[0081] Since ultrasonic welding can achieve controllable deformation and the welding process is stable, its connection strength is significantly higher than that of solder paste reflow soldering, thereby effectively improving the reliability of the module.

[0082] Reference Figure 8 The implementation process of the injection molding packaging process of the present invention is as follows:

[0083] Step S1, grab the power terminal 4 by the welding head 91 of the ultrasonic welding device 9, place the power terminal 4 on the emitter 11 of the metallized ceramic substrate 1, and perform ultrasonic welding;

[0084] Step S2, the metal part 2 is loaded through the vibrating plate;

[0085] Step S3, the welding head 91 absorbs and grasps the metal part 2 through the vacuum absorption hole 92 and places it on the emitter 11 of the metallized ceramic substrate 1 to perform ultrasonic welding;

[0086] Step S4, injecting the shell material into a preset mold to form a half-bridge structure;

[0087] Step S5, the PIN needle 3 is loaded through the vibration plate;

[0088] In step S6, the welding head 91 absorbs and grabs the PIN needle 3 through the vacuum absorption hole 92 and places it on the emitter 11 of the metallized ceramic substrate 1 to perform ultrasonic welding.

[0089] 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 power module with front-side pins, characterized in that: include, Metallized ceramic substrate; A metal piece, the metal piece comprising a flat welding bottom surface and a flat welding surface, the welding bottom surface of the metal piece being connected to the emitter of the metallized ceramic substrate by ultrasonic welding; A PIN needle is vertically arranged on the welding surface of the metal part by ultrasonic welding.

2. The power module with front-side pin outlet according to claim 1, characterized in that: The PIN needle is cylindrical and is made of copper material.

3. The power module with front-side pin outlet according to claim 1, characterized in that: The metal piece is cylindrical and made of copper. The width of the metal piece is 2 mm to 6 mm.

4. The power module with front-side pin outlet according to claim 1, characterized in that: The emitter of the metallized ceramic substrate is also connected to a power terminal by ultrasonic welding.

5. The power module with front-side pin outlet according to claim 1, characterized in that: A semiconductor device is also arranged on the emitter of the metallized ceramic substrate, and solder is arranged between the semiconductor device and the emitter of the metallized ceramic substrate.

6. The power module with front-side pin outlet according to claim 5, characterized in that: The semiconductor device at least includes a power chip and a diode. The semiconductor device is connected to the emitter of the metallized ceramic substrate via a metal bonding wire, and the semiconductor devices are connected to each other via the metal bonding wire.

7. The power module with front-side pin outlet according to claim 5, characterized in that: It also includes a heat dissipation substrate, which is arranged on the back side of the metallized ceramic substrate, and the area of ​​the heat dissipation substrate is larger than the area of ​​the power module.

8. The power module with front-side pin outlet according to claim 7, characterized in that: It also includes a shell, which is arranged on the heat dissipation substrate, or the shell is connected to the outer side of the heat dissipation substrate.

9. The power module with front-side pin outlet according to claim 8, characterized in that: The housing is connected to the heat dissipation substrate to form an accommodation space, in which the metallized ceramic substrate, the metal piece and the PIN needle are arranged, and one end of the PIN needle vertically extends upward out of the housing.

10. The power module with front-side pin outlet according to claim 7, characterized in that: The solder is disposed between the heat dissipation substrate and the metallized ceramic substrate, and the solder includes at least one of tin-lead, tin-silver, tin-silver-copper, and lead-tin-silver.

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