A packaging structure

Abstract

The utility model provides a kind of packaging structure, including substrate, chip, heat sink, copper clamp, isolation structure, pre-sintering soldering sheet and package, chip is arranged on substrate, heat sink is arranged on the side of substrate away from chip;Copper clamp includes first connecting part and second connecting part, first connecting part is used to be connected with chip electricity, and second connecting part is used to be connected with substrate electricity;Isolation structure is arranged between first connecting part and chip;Pre-sintering soldering sheet first connecting part and isolation structure, isolation structure and chip, and second connecting part and substrate between, all are connected by pre-sintering soldering sheet using ultrasonic welding;Package is used to cover substrate, chip, heat sink, copper clamp and isolation structure, heat sink is partially exposed to package.The utility model is favorable to guarantee the reliability of packaging structure in high vibration, high temperature gradient environment.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to a packaging structure. Background Technology

[0002] In the field of semiconductor packaging technology, especially in the packaging processes of automotive-grade and industrial-grade power modules, the electrical connectivity and heat dissipation performance of the chip are core factors determining the reliability and efficiency of the module. In traditional packaging processes, the electrical connection between the chip and external circuits is mostly achieved through wire bonding, that is, by connecting the electrodes on the chip surface to the substrate or lead frame through thin metal wires (such as aluminum wires, gold wires, etc.) to achieve current transmission. At the same time, to meet heat dissipation requirements, a ceramic substrate is usually used to fix the chip to a heat sink using solder (such as tin-lead alloy, lead-free solder, etc.), forming a heat dissipation path from the chip to the heat sink.

[0003] However, as industrial equipment, automotive electronics, aerospace, and other fields increasingly demand higher power density, current transmission capacity, and thermal management from power modules, traditional processes are gradually revealing certain technical shortcomings. Because the metal wires used in wire bonding have a small cross-sectional area, they are prone to significant resistance losses under high-current conditions, and parasitic inductance exists between the wires, limiting the module's high-frequency performance. Furthermore, traditional soldering has a low thermal conductivity, and the soldering process is prone to uneven melting and residual bubbles, leading to voids that increase thermal resistance between the chip and substrate, and between the substrate and heat sink, ultimately resulting in limited current transmission capacity and insufficient heat dissipation efficiency. At the same time, traditional soldering processes are complex (such as solder paste printing and reflow soldering), requiring stringent environmental cleanliness and temperature control precision. Human error or parameter fluctuations can easily lead to decreased product consistency and poor adaptability to automated production.

[0004] Therefore, a new solution is needed to address the aforementioned technical problems. Utility Model Content

[0005] This invention provides a packaging structure to solve the technical problems of limited current transmission capability and insufficient heat dissipation efficiency in related technologies.

[0006] This utility model provides a packaging structure, which includes: a substrate, a chip, a heat sink, a copper clip, an isolation structure, a pre-sintered solder pad, and a package body. The chip is disposed on the substrate, and the heat sink is disposed on the side of the substrate opposite to the chip. The copper clip includes a first connecting portion and a second connecting portion, the first connecting portion being used for electrical connection with the chip, and the second connecting portion being used for electrical connection with the substrate. The isolation structure is disposed between the first connecting portion and the chip. The pre-sintered solder pad is ultrasonically welded to the first connecting portion and the isolation structure, the isolation structure and the chip, and the second connecting portion and the substrate. The package body covers the substrate, the chip, the heat sink, the copper clip, and the isolation structure, with the heat sink partially exposed outside the package body.

[0007] In one embodiment of the present invention, the copper clip further includes a copper clip body, the first connecting portion and the second connecting portion are disposed at both ends of the copper clip body and are bent relative to the copper clip body, and the first connecting portion and the second connecting portion are disposed opposite to each other.

[0008] In one embodiment of the present invention, a stress relief hole is provided on the side of the first connecting portion near the copper clip body.

[0009] In one embodiment of this utility model, the copper clip is configured as a thin copper sheet.

[0010] In one embodiment of this utility model, the isolation structure is configured as a pure copper block conductive interconnect post, and the thickness of the pure copper block conductive interconnect post is less than 3mm.

[0011] In one embodiment of the present invention, the pre-sintered solder sheet is configured as a silver-copper alloy pre-sintered solder sheet, the first side of the pre-sintered solder sheet is configured as a silver layer, the second side of the pre-sintered solder sheet is configured as a copper layer, and the first side and the second side are arranged opposite to each other.

[0012] In one embodiment of the present invention, the substrate is a ceramic substrate, which includes a first copper layer, a ceramic carrier plate and a second copper layer arranged sequentially from top to bottom. The chip is disposed on the first copper layer and the heat sink is connected to the second copper layer.

[0013] In one embodiment of the present invention, the side of the heat sink away from the substrate is exposed in the package, and mounting holes are provided at both ends of the heat sink along its length, the mounting holes being exposed in the package.

[0014] In one embodiment of this utility model, the heat sink is configured as a copper substrate.

[0015] In one embodiment of the present invention, a plurality of chips are disposed on each substrate, each chip is configured with the isolation structure and the copper clip, and a plurality of substrates are disposed on the heat sink.

[0016] The beneficial effects of this utility model are as follows: The packaging structure proposed in this utility model achieves electrical connection between the chip and the substrate by connecting the first connecting part of the copper clip to the chip and the second connecting part of the copper clip to the substrate. The use of copper clips instead of wire bonding increases the conductive cross-sectional area, which is beneficial for meeting the high-frequency operation of the packaging structure. In addition, an isolation structure is provided between the first connecting part and the chip, which increases the heat dissipation path and is beneficial for improving heat conduction efficiency. Furthermore, the first connecting part and the isolation structure, the isolation structure and the chip, and the second connecting part and the substrate are all connected by ultrasonic welding through pre-sintered solder pads, which is beneficial for improving the mechanical strength of the connection between structural components and ensuring the reliability of the packaging structure under high vibration and high temperature gradient environments. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram:

[0019] Figure 1 The packaging structure provided in one embodiment of this utility model;

[0020] Figure 2 for Figure 1 A magnified view of part A in the middle.

[0021] The attached figures are labeled as follows:

[0022] 1-Heat sink; 11-Mounting holes;

[0023] 2-Substrate;

[0024] 3-Chip;

[0025] 4-Isolation structure;

[0026] 5-Copper clip; 51-First connecting part; 52-Second connecting part; 53-Copper clip body; 54-Stress relief hole. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0030] Please see Figure 1 This utility model provides a packaging structure including a heat sink 1, a substrate 2, a chip 3, an isolation structure 4, a copper clip 5, a pre-sintered solder pad, and a package body. The package body covers the heat sink 1, the substrate 2, the chip 3, the isolation structure 4, and the copper clip 5. Partially, the heat sink 1 is exposed outside the package body to improve its heat dissipation efficiency.

[0031] Substrate 2 is mounted on heat sink 1, and chip 3 is mounted on substrate 2. Copper clip 5 includes a first connecting portion 51 and a second connecting portion 52. The first connecting portion 51 is used for electrical connection with chip 3, and the second connecting portion 52 is used for electrical connection with substrate 2, thus realizing the electrical connection between chip 3 and substrate 2. Furthermore, using copper clip 5 instead of wire bonding increases the conductive cross-sectional area, which is beneficial for meeting the high-frequency operation requirements of the package structure. It should be noted that the isolation structure 4 is located between chip 3 and the first connecting portion 51, which helps to improve current transmission density and the instantaneous heat dissipation capability of chip 3.

[0032] Furthermore, the first connecting part 51 and the isolation structure 4, the isolation structure 4 and the chip 3, and the second connecting part 52 and the substrate 2 are all connected by ultrasonic welding using pre-sintered solder pads. This avoids the problems of high void ratio and high thermal resistance caused by using traditional solder in the above structures, which is conducive to improving the mechanical strength of the connection between structural components, and thus helps to ensure the reliability of the packaging structure in high vibration and high temperature gradient environments.

[0033] For example, the side of the heat sink 1 facing away from the substrate 2 is exposed to the package body, so that the heat sink 1 can quickly dissipate heat through the side exposed to the package body, thereby improving the heat dissipation efficiency of the heat sink 1. Mounting holes 11 are provided at both ends of the heat sink 1 along its length, and these mounting holes 11 are exposed to the package body, so that the package structure can be mounted on other structural components through the mounting holes 11.

[0034] In one example, multiple chips 3 are disposed on each substrate 2, thereby improving the space utilization of the substrate 2, which is beneficial for reducing costs and enhancing functional flexibility. Exemplarily, the multiple chips 3 can be arranged in one column or multiple columns, with each column containing multiple chips 3. In this embodiment, two columns of chips 3 are disposed on one substrate 2, with four chips 3 in each column, and the two columns of chips 3 are staggered. It should be noted that each chip 3 is equipped with an isolation structure 4 and a copper clip 5, thereby achieving electrical connection between each chip 3 and the substrate 2.

[0035] Multiple substrates 2 are provided on the heat sink 1, which helps to improve heat dissipation efficiency and enhance thermal management capabilities.

[0036] For example, the heat sink 1 is set as a copper substrate, which is beneficial for the heat sink 1 to dissipate heat through heat conduction.

[0037] In one example, substrate 2 is a ceramic substrate, which includes a first copper layer, a ceramic carrier, and a second copper layer arranged sequentially from top to bottom. Chip 3 is disposed on the first copper layer, and heat sink 1 is connected to the second copper layer.

[0038] In some embodiments, the isolation structure 4 is configured as a pure copper block conductive interconnect post, which optimizes signal integrity while also enhancing heat dissipation. To match current requirements, the thickness of the pure copper block conductive interconnect post is less than 3mm, which helps reduce overall weight and cost while also ensuring signal integrity.

[0039] In some embodiments, the copper clip 5 further includes a copper clip body 53, with a first connecting portion 51 and a second connecting portion 52 disposed at both ends of the copper clip body 53 and bent relative to the copper clip body 53, and the first connecting portion 51 and the second connecting portion 52 disposed opposite to each other. This arrangement is beneficial for the welding operation between the copper clip 5 and the chip 3, and between the copper clip 5 and the substrate 2.

[0040] In one example, a stress relief hole 54 is provided on the side of the first connecting part 51 near the copper clip body 53. The provision of the stress relief hole 54 helps to reduce stress, thereby helping to improve the service life of the copper clip 5.

[0041] For example, copper clip 5 is configured as a thin copper sheet.

[0042] In some embodiments, the pre-sintered solder sheet is configured as a silver-copper alloy pre-sintered solder sheet, which is beneficial for optimizing thermal conductivity and enhancing heat dissipation efficiency. Specifically, the first side of the pre-sintered solder sheet is configured with a silver layer, and the second side is configured with a copper layer, with the first and second sides positioned opposite each other.

[0043] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A packaging structure, characterized in that, include: substrate; The chip is disposed on the substrate; A heat sink is disposed on the side of the substrate opposite to the chip; The copper clip includes a first connecting portion and a second connecting portion, wherein the first connecting portion is used for electrical connection with the chip, and the second connecting portion is used for electrical connection with the substrate; An isolation structure is disposed between the first connection portion and the chip; The pre-sintered solder pad is used to connect the first connecting portion and the isolation structure, the isolation structure and the chip, and the second connecting portion and the substrate, all by ultrasonic welding. A package for encapsulating the substrate, the chip, the heat sink, the copper clip, and the isolation structure, wherein the heat sink is partially exposed outside the package.

2. The packaging structure according to claim 1, characterized in that: The copper clip also includes a copper clip body, with the first connecting portion and the second connecting portion disposed at both ends of the copper clip body and bent relative to the copper clip body, and the first connecting portion and the second connecting portion being disposed opposite to each other.

3. The packaging structure according to claim 2, characterized in that: A stress relief hole is provided on the side of the first connecting part near the copper clip body.

4. The packaging structure according to claim 1, characterized in that: The copper clip is made of a thin copper sheet.

5. The packaging structure according to claim 1, characterized in that: The isolation structure is configured as a pure copper block conductive interconnect pillar, and the thickness of the pure copper block conductive interconnect pillar is less than 3mm.

6. The packaging structure according to claim 1, characterized in that: The pre-sintered solder sheet is configured as a silver-copper alloy pre-sintered solder sheet, with a silver layer on the first side and a copper layer on the second side, and the first and second sides are arranged opposite to each other.

7. The packaging structure according to claim 1, characterized in that: The substrate is a ceramic substrate, which includes a first copper layer, a ceramic carrier plate and a second copper layer arranged sequentially from top to bottom. The chip is disposed on the first copper layer and the heat sink is connected to the second copper layer.

8. The packaging structure according to claim 1, characterized in that: The heat sink is exposed on the side away from the substrate in the package, and mounting holes are provided at both ends of the heat sink along its length, which are exposed in the package.

9. The packaging structure according to claim 8, characterized in that: The heat sink is made of copper substrate.

10. The packaging structure according to any one of claims 1-9, characterized in that: Each of the substrates is provided with a plurality of the chips, each of the chips is provided with the isolation structure and the copper clip, and the heat sink is provided with a plurality of the substrates.

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