A high heat dissipation thick film hybrid circuit package structure

Abstract

This utility model relates to circuit packaging structures, specifically a high-heat-dissipation thick-film hybrid circuit packaging structure. It includes a packaging shell and a heat-dissipating substrate located at the bottom inner side of the packaging shell. The heat-dissipating substrate has multiple matrix-distributed heat-dissipating through-holes, each containing a heat-conducting pillar. The top of the heat-dissipating substrate has multiple electronic component mounting areas, where electronic components are mounted. Both sides of the heat-dissipating substrate have multiple uniformly distributed heat-dissipating fins. Silicone-modified epoxy resin is filled between the inner wall of the packaging shell and the top of the heat-dissipating substrate, the outer wall of the electronic components, and the outer wall of the heat-dissipating fins. A heat-dissipating coating is applied to the outer surface of the packaging shell. By forming a three-dimensional heat dissipation channel through the heat-dissipating substrate and the heat-conducting pillars within the heat-dissipating through-holes, and by applying a heat-dissipating coating to the outer wall of the packaging shell, a comprehensive, multi-layered, high-efficiency heat dissipation system is formed, greatly improving the circuit's heat dissipation capability.

Description

Technical Field

[0001] This utility model relates to circuit packaging structures, specifically to a high heat dissipation thick-film hybrid circuit packaging structure. Background Technology

[0002] With the rapid development of electronic technology, thick-film hybrid circuits play a crucial role in numerous fields. In today's era, the performance requirements for electronic devices continue to rise, and various industries are pursuing higher integration, stronger functionality, and better reliability. Thick-film hybrid circuits have emerged due to their unique advantages. They integrate multiple electronic components into a single unit, possessing high integration characteristics, enabling complex circuit functions to be implemented in a relatively small space, meeting the needs of devices for multi-functional integration; simultaneously, they exhibit excellent electrical performance, ensuring efficient and accurate signal transmission; and they also possess high-temperature resistance, allowing them to adapt to some harsh working environments.

[0003] Focusing on specific fields such as aerospace, automotive electronics, and communication equipment. In the aerospace field, the requirements for equipment reliability and stability are extremely high. Spacecraft operate in extreme space environments, and thick-film hybrid circuits must withstand cosmic rays and drastic temperature changes; their high-temperature resistance and high reliability are key factors in their selection. In automotive electronics, as cars move towards intelligence and electrification, in-vehicle electronic systems are becoming increasingly complex. Thick-film hybrid circuits can integrate numerous functional modules within limited space, contributing to the miniaturization and high performance of automotive electronic systems. In the field of communication equipment, especially with the advent of 5G and even higher-speed communication in the future, signal processing power has increased significantly. The high integration of thick-film hybrid circuits can meet the needs of high-frequency and high-speed signal processing.

[0004] However, existing technical solutions have revealed many shortcomings when facing the further development needs of thick-film hybrid circuits: heat dissipation bottlenecks, large package size, and limited protection capabilities. Although thick-film hybrid circuits have many inherent advantages, the shortcomings of existing technologies seriously restrict their development and wider application, and new technical solutions are urgently needed to overcome these bottlenecks. Utility Model Content

[0005] The purpose of this invention is to solve the technical problem of insufficient heat dissipation capacity of existing hybrid circuit packaging structures, and to provide a high heat dissipation thick-film hybrid circuit packaging structure.

[0006] To solve the above-mentioned technical problems, the technical solution provided by this utility model is as follows:

[0007] A high heat dissipation thick-film hybrid circuit packaging structure includes a packaging shell and a heat dissipation substrate located at the bottom of the inner side of the packaging shell.

[0008] The heat dissipation substrate has multiple heat dissipation through holes arranged in a matrix, and heat conduction pillars are provided in the heat dissipation through holes; the top of the heat dissipation substrate has multiple electronic component mounting areas, and electronic components are mounted in the electronic component mounting areas.

[0009] Both sides of the heat dissipation substrate are provided with multiple evenly distributed heat dissipation fins.

[0010] The inner wall of the encapsulation tube shell forms an encapsulation space with the top of the heat dissipation substrate, the outer wall of the electronic component, and the outer wall of the heat dissipation fins. The encapsulation space is filled with silicone-modified epoxy resin.

[0011] The outer surface of the encapsulation casing is provided with a heat dissipation coating.

[0012] Furthermore, the heat dissipation substrate includes a Cu-Mo-Cu alloy layer and an AlN ceramic layer distributed sequentially from bottom to top;

[0013] The thickness of the Cu-Mo-Cu alloy layer is 0.5-1.0 mm, and the Cu-Mo-Cu alloy layer is composed of 30% Cu and 70% Mo;

[0014] The AlN ceramic layer has a thickness of 0.2-0.4 mm and comprises 5%-15% polyvinyl alcohol, 3%-10% polyethylene glycol and 1%-5% triethanolamine, with the balance being AlN.

[0015] Furthermore, the heat-conducting pillar is a silver-copper composite metal, wherein the silver-copper composite metal comprises 30% silver and 70% copper.

[0016] Furthermore, the height of the heat dissipation fins is 2mm, and the spacing between two adjacent heat dissipation fins is 1mm.

[0017] Furthermore, the thickness of the heat dissipation coating is 0.05 mm;

[0018] The heat dissipation coating is graphene, carbon nanotube coating, boron nitride coating, aluminum nitride coating, or silver coating.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] 1. The high heat dissipation thick-film hybrid circuit packaging structure provided by this utility model forms a three-dimensional heat dissipation channel through a heat dissipation substrate and heat-conducting pillars filled in the heat dissipation through-holes on the heat dissipation substrate. Heat dissipation is achieved through the simultaneous heat dissipation of the heat dissipation substrate and the heat-conducting pillars, thereby improving the heat dissipation efficiency of electronic components mounted on the surface of the heat dissipation substrate. Furthermore, a heat dissipation coating is provided on the outer wall of the package shell. The thermal conductivity of the heat dissipation coating can further enhance the heat dissipation performance, working in conjunction with the heat dissipation substrate to form a comprehensive, multi-layered, high-efficiency heat dissipation system, which greatly improves the heat dissipation capacity of the circuit. Compared with the traditional method of relying on the heat dissipation of the substrate plane and the single heat dissipation path, it can promptly dissipate the large amount of heat generated by the operation of the thick-film hybrid circuit, avoiding problems such as performance degradation and failure of chips and components due to high temperature. For example, in high-power signal processing scenarios, it can ensure stable circuit operation and guarantee signal quality.

[0021] 2. The high heat dissipation thick film hybrid circuit packaging structure provided by this utility model has a heat dissipation substrate composed of a Cu-Mo-Cu alloy layer and an AlN ceramic layer. The lower Cu-Mo-Cu alloy layer is used for rapid lateral conduction and heat dissipation, while the upper AlN ceramic layer assists in heat dissipation.

[0022] 3. The high heat dissipation thick-film hybrid circuit packaging structure provided by this utility model combines the excellent properties of epoxy resin and silicone materials with the adhesiveness and mechanical strength of epoxy resin and the excellent temperature resistance, moisture resistance and flexibility of silicone materials. Compared with the limited protection capabilities of traditional packaging, which is susceptible to moisture and dust, resulting in short circuits, corrosion and poor contact, this utility model provides a reliable and durable protective barrier for thick-film hybrid circuits, extends the service life of the circuit, and ensures its long-term stable operation in harsh environments such as outdoor and industrial environments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the heat dissipation substrate in an embodiment of this utility model;

[0025] Figure 3 This is a flowchart of the preparation method according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached drawings: 1-Encapsulation housing, 2-Heat dissipation substrate, 3-Heat dissipation through hole, 4-Electronic component, 5-Heat dissipation fin, 6-Encapsulation space, 7-Heat dissipation coating, 8-Cu-Mo-Cu alloy layer, 9-AlN ceramic layer. Detailed Implementation

[0027] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] like Figure 1 As shown, a high-heat-dissipation thick-film hybrid circuit package structure includes a package housing 1 and a heat-dissipating substrate 2 located at the bottom inner side of the package housing 1; as shown Figure 2 As shown, the heat dissipation substrate 2 has multiple heat dissipation through holes 3 arranged in a matrix, and heat conduction pillars are provided in the heat dissipation through holes 3; the top of the heat dissipation substrate 2 has multiple electronic component 4 mounting areas, and the electronic components 4 are mounted in the electronic component 4 mounting areas.

[0029] like Figure 1 and Figure 2 As shown, in order to dissipate heat quickly from the heat dissipation substrate 2, multiple evenly distributed heat dissipation fins 5 are provided on both sides of the heat dissipation substrate 2; the height of the heat dissipation fins 5 is 2mm, and the distance between two adjacent heat dissipation fins 5 is 1mm.

[0030] The inner wall of the encapsulation shell 1 and the top of the heat dissipation substrate 2, the outer wall of the electronic component 4, and the outer wall of the heat dissipation fins 5 form an encapsulation space 6. In order to meet the mechanical performance requirements of the encapsulation and maximize the protection capability of the hybrid thick film circuit and resist the erosion of external factors such as moisture and dust, the encapsulation space 6 is filled with silicone-modified epoxy resin. The silicone-modified epoxy resin has the adhesiveness and mechanical strength of epoxy resin as well as the excellent temperature resistance, moisture resistance and flexibility of silicone materials.

[0031] To rapidly conduct heat from the encapsulation shell 1 to the external environment and further enhance heat dissipation efficiency, a heat dissipation coating 7 is provided on the outer surface of the encapsulation shell 1. The thickness of the heat dissipation coating 7 is 0.05 mm. The heat dissipation coating 7 can be a graphene coating, a carbon nanotube coating, a boron nitride coating, an aluminum nitride coating, or a silver coating. The thermal conductivity of the heat dissipation coating 7 is utilized to achieve rapid heat conduction from the encapsulation shell 1.

[0032] like Figure 1 and Figure 2 As shown, the heat dissipation substrate 2 includes a Cu-Mo-Cu alloy layer 8 and an AlN ceramic layer 9 distributed sequentially from bottom to top; the thickness of the Cu-Mo-Cu alloy layer 8 is 0.5-1.0 mm, and the Cu-Mo-Cu alloy layer 8 is composed of 30% Cu and 70% Mo.

[0033] The AlN ceramic layer 9 has a thickness of 0.2-0.4 mm and includes 5%-15% polyvinyl alcohol, 3%-10% polyethylene glycol and 1%-5% triethanolamine, with the balance being AlN.

[0034] The heat-conducting pillar is a silver-copper composite metal, which consists of 30% silver and 70% copper.

[0035] like Figure 3 As shown, the specific method for fabricating the above-mentioned high heat dissipation thick-film hybrid circuit package structure is as follows:

[0036] 1) Multiple uniformly distributed heat dissipation fins 5 are cast on both sides of the heat dissipation substrate 2 using a casting process.

[0037] The method for preparing the heat dissipation substrate 2 is as follows:

[0038] The raw materials for preparing the Cu-Mo-Cu alloy layer 8 consist of 30% Cu powder and 70% Mo powder.

[0039] After mixing Cu powder and 70% Mo powder, the mixture is sintered at 1000-1200℃ and 50-100MPa to form a Cu-Mo-Cu alloy layer with a thickness of 0.5-1.0mm.

[0040] The raw materials for preparing the AlN ceramic layer 9 include 5%-15% polyvinyl alcohol, 3%-10% polyethylene glycol and 1%-5% triethanolamine, with the balance being AlN;

[0041] AlN is mixed with polyvinyl alcohol, polyethylene glycol and triethanolamine to prepare a casting slurry, and an AlN ceramic layer 9 preform with a thickness of 0.2-0.4 mm is formed on the surface of Cu-Mo-Cu alloy layer 8 using a casting machine;

[0042] After drying and degreasing, the AlN ceramic layer 9 preform is sintered in a nitrogen atmosphere at 1600-1800℃ to form the AlN ceramic layer 9; thus completing the preparation of the heat dissipation substrate 2.

[0043] 2) Heat dissipation through-holes 3 are fabricated on the upper surface of the heat dissipation substrate 2 using photolithography and etching processes. After the through-holes are formed, heat-conducting pillars are filled in and then sintered. The specific method for filling the heat-conducting pillars and sintering is as follows:

[0044] The raw materials used to configure the heat-conducting pillars include 30% silver and 70% copper;

[0045] Silver and copper are mixed to form a silver-copper composite metal paste, which is then filled into the heat dissipation through hole 3.

[0046] After filling, the heat dissipation substrate 2 is placed in an electric heating furnace and subjected to stepped sintering under a hydrogen protective atmosphere.

[0047] First stage: Heat the electric heating furnace to 300℃ and heat the silver-copper composite metal slurry at 300℃ for 30 minutes;

[0048] Second stage: Heat the electric heating furnace to 600℃ and heat the silver-copper composite metal slurry at 600℃ for 45 minutes;

[0049] The third stage: Heat the electric heating furnace to 850℃ and heat the silver-copper composite metal slurry at 850℃ for 15 minutes;

[0050] After heating is complete, the heat-conducting column is filled and sintered.

[0051] 3) Perform chemical mechanical polishing on the upper surface of the heat dissipation substrate 2 obtained in step 2) to make the surface roughness Ra = 0.3 μm, and then use plasma cleaning to clean the upper surface of the heat dissipation substrate 2 for 5 min.

[0052] The specific method for cleaning the upper surface of the heat dissipation substrate 2 using plasma is as follows:

[0053] The heat dissipation substrate 2 is placed in a plasma cleaner. The plasma cleaner uses a power of 300W to generate plasma from a mixture of argon and oxygen, and bombards the surface of the heat dissipation substrate 2 with the plasma to achieve plasma cleaning of the upper surface of the heat dissipation substrate 2.

[0054] The mixing ratio of argon and oxygen is 4:1.

[0055] 4) Place the electronic component 4 on the electronic component 4 mounting area on the heat sink substrate 2 using a high-precision pick and place machine, and mount the electronic component 4 in the electronic component 4 mounting area;

[0056] 5) Fix the heat dissipation substrate 2 with the electronic components 4 mounted inside the encapsulation shell 1, and use a vacuum potting device to inject silicone-modified epoxy resin with a viscosity of 5000cps into the encapsulation space 6.

[0057] The filling vacuum degree is ≤10Pa, the filling speed is 10ml / min, and the filling temperature is 25℃;

[0058] After potting, the encapsulated tube shell 1 is placed in an oven and pre-cured at 80°C for 1 hour; after pre-curing, it is mainly cured at 150°C for 2 hours; after main curing, it is post-cured at 180°C for 1 hour to complete the curing of the silicone-modified epoxy resin inside the encapsulated tube shell 1.

[0059] 6) Place the encapsulated shell 1 in the reaction chamber of the CVD reactor, introduce the mixed gas of methane and hydrogen into the reaction chamber, heat the temperature of the CVD reactor to 1000℃, and the mixed gas of methane and hydrogen reacts chemically with the outer surface of the encapsulated shell 1 for 30 minutes.

[0060] After the reaction is complete, a heat dissipation coating 7 is formed on the outer surface of the package 1, thus completing the preparation of the high heat dissipation thick film hybrid circuit package structure.

[0061] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A high heat dissipating thick film hybrid circuit package structure, characterized by: It includes a package housing (1) and a heat dissipation substrate (2) located at the bottom inside the package housing (1); The heat dissipation substrate (2) has multiple heat dissipation through holes (3) arranged in a matrix, and heat conduction pillars are provided in the heat dissipation through holes (3); the top of the heat dissipation substrate (2) has multiple electronic component (4) mounting areas, and the electronic components (4) are mounted in the electronic component (4) mounting areas. The heat dissipation substrate (2) has multiple evenly distributed heat dissipation fins (5) on both sides. The inner wall of the encapsulation shell (1) forms an encapsulation space (6) between the top of the heat dissipation substrate (2), the outer wall of the electronic component (4), and the outer wall of the heat dissipation fin (5), and the encapsulation space (6) is filled with silicone-modified epoxy resin. The outer surface of the encapsulation shell (1) is provided with a heat dissipation coating (7).

2. The high heat dissipating thick film hybrid circuit package structure of claim 1, wherein: The height of the heat dissipation fins (5) is 2mm, and the distance between two adjacent heat dissipation fins (5) is 1mm.

3. The high heat dissipating thick film hybrid circuit package structure of claim 1, wherein: The thickness of the heat dissipation coating (7) is 0.05 mm; The heat dissipation coating (7) is graphene, carbon nanotube coating, boron nitride coating, aluminum nitride coating or silver coating.

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