High-dielectric-constant high-performance film for semiconductor and preparation method thereof

Abstract

The invention relates to the field of high-dielectric polymer film materials, and particularly discloses a high-dielectric-constant high-performance film for semiconductors and a preparation method of the high-dielectric-constant high-performance film. The high-dielectric constant and high-performance film for the semiconductor is prepared from the following raw materials in parts by weight: 35 to 45 parts of pyromellitic dianhydride, 30 to 40 parts of 4, 4 '-diaminodiphenyl ether, 20 to 30 parts of carbon nanotubes, 50 to 70 parts of a solvent, 5 to 8 parts of a flexibilizer and 0.5 to 1.5 parts of a catalyst, the preparation method comprises the following steps: S1, enabling pyromellitic dianhydride, 4, 4 '-diaminodiphenyl ether, carbon nanotubes, a solvent, a flexibilizer and a catalyst to react to prepare a polyamide solution; s2, coating a base material with the polyamide solution in a curtain coating manner, and heating for imidization reaction; the high-dielectric-constant and high-performance film prepared by the invention is suitable for semiconductor chip packaging, has a relatively high dielectric constant, is not easy to deform when being bent, and is not easy to cause the problem of edge separation after being used for a long time.

Description

Technical Field

[0001] The present application relates to the field of high dielectric constant polymer film materials, and more particularly, to a high dielectric constant and high performance film for semiconductors and a preparation method thereof. Background Art

[0002] Polyimide film has high insulation resistance and good dielectric properties, which can effectively prevent electron migration and corrosion. As a passivation layer and buffer inner coating, it can protect the circuit inside the chip from external factors and improve the overall performance and reliability of the chip. At the same time, polyimide film has good flexibility and mechanical strength, which can adapt to chip substrates of different shapes and sizes, and can withstand certain bending and tensile stresses, making it suitable for flexible semiconductor chip packaging.

[0003] However, when polyimide film is used in thin and lightweight (generally 10-20 μm thick) flexible semiconductor chip packaging, it is prone to irreversible deformation and bending problems, and edge separation problems are prone to long-term operation in high-temperature environments, reducing the applicability of polyimide film. Summary of the Invention

[0004] In order to solve the problem that polyimide film is prone to bending deformation and edge separation when used in lightweight and thin flexible semiconductor chip packaging, the present application provides a high dielectric constant and high performance film for semiconductors and a preparation method thereof.

[0005] In a first aspect, the present application provides a high dielectric constant and high performance film for semiconductors, which adopts the following technical solution: A high dielectric constant and high performance film for semiconductors is prepared from the following raw materials in parts by weight: 35-45 parts of pyromellitic dianhydride 30-40 parts of 4,4'-diaminodiphenyl ether 20-30 parts of carbon nanotubes 50-70 parts solvent 5-8 parts of flexibilizer 0.5-1.5 parts of catalyst.

[0006] By adopting the above technical solution, under the action of a catalyst, pyromellitic dianhydride and 4,4'-diaminodiphenyl ether undergo a polymerization reaction to form a polyimide matrix material, which imparts a high dielectric constant and good heat resistance to the film. Carbon nanotubes can produce a good synergistic effect with the polyimide matrix material, significantly improving the mechanical strength and dielectric properties of the film. The choice of solvent ensures uniform dispersion of the raw materials and fluidity of the solution, facilitating the subsequent cast coating process. The flexibilizer further synergizes with the system to enhance the flexibility of the film, allowing it to adapt to chip substrates of various shapes and sizes, while also being less susceptible to edge separation issues during long-term use. The resulting high-performance film not only possesses a high dielectric constant, but also excellent mechanical properties and reliability, making it particularly suitable for the field of lightweight and flexible semiconductor chip packaging.

[0007] Preferably, the carbon nanotubes are modified carbon nanotubes, which are prepared by the following steps: A1. Add 20-30 parts of carbon nanotubes to 10-20 parts of ethanol aqueous solution, then add 0.2-0.4 parts of bisamino functional silane and 0.3-0.5 parts of trihydroxy polyoxypropylene ether, heat and stir, and filter to obtain pretreated carbon nanotubes; A2. Add 0.4-0.8 parts of long-chain alkyl glycidyl ether to the pretreated carbon nanotubes, knead and disperse, and prepare modified carbon nanotubes.

[0008] By adopting the above technical solution, the present applicant further modified the carbon nanotubes, as they are difficult to disperse. The modified carbon nanotubes were pretreated with diamino-functional silane and trihydroxy polyoxypropylene ether, effectively improving the activity and dispersibility of the carbon nanotube surface. Subsequently, long-chain alkyl glycidyl ether was further dispersed and adsorbed on the pretreated carbon nanotubes, forming a stable chemically modified layer on the carbon nanotube surface, significantly enhancing its compatibility and bonding with the polyimide matrix. This improvement not only increased the mechanical strength and flexibility of the high-performance membrane, but also improved the dielectric properties and thermal stability of the membrane material.

[0009] Preferably, the long-chain alkyl glycidyl ether in step A2 is a C12 to C18 alkyl glycidyl ether.

[0010] By employing this technical solution, the use of C12-C18 alkyl glycidyl ether further enhances the surface modification of carbon nanotubes, improving their compatibility and bonding with the polyimide matrix. This significantly improves the material's flexibility and mechanical properties, effectively reducing the irreversible deformation that occurs during bending and stretching. It also improves the film's edge stability, reducing the risk of edge separation during long-term high-temperature operation, further enhancing the film's suitability for flexible semiconductor chip packaging.

[0011] Preferably, the stirring temperature in step A1 is 60-70°C, and the kneading temperature in step A2 is 180-200°C.

[0012] By adopting the above technical solution, controlling the stirring temperature in step A1 to 60-70°C can effectively promote the uniform dispersion and chemical bonding of diamino functional silane and trihydroxy polyoxypropylene ether with carbon nanotubes, thereby improving the surface activity and dispersion stability of the modified carbon nanotubes; at the same time, controlling the kneading temperature in step A2 to 180-200°C is conducive to full contact between long-chain alkyl glycidyl ether and pretreated carbon nanotubes, enhancing the flexibility and interfacial bonding strength of the carbon nanotubes, thereby further improving the mechanical properties and bending resistance of the high-performance membrane.

[0013] Preferably, the carbon nanotubes are double-walled carbon nanotubes with a diameter of 1-2 nm and a length of 0.5-2 μm.

[0014] By adopting the above technical solution and using double-walled carbon nanotubes with better specifications and parameters, while ensuring good conductivity, it provides better flexibility and strength, making the high-performance film less likely to bend and deform.

[0015] Preferably, the flexibilizer is composed of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate in a weight ratio of 1:(2-4).

[0016] By adopting this technical solution, the flexibilizer, composed of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate in a specific weight ratio, effectively improves the flexibility of high-dielectric-constant, high-performance films, reducing stress concentration during bending and stretching, thereby lowering the risk of irreversible deformation. It also enhances dimensional stability in high-temperature environments and prevents edge separation.

[0017] Preferably, the catalyst is any one or a combination of diethylamine, triethylamine, triethylenediamine, N,N'-diethylpiperazine and N,N'-diethyl-2-methylpiperazine.

[0018] By adopting the above technical solution, the catalyst can effectively promote the polymerization reaction of polyimide, improve the reaction efficiency and the uniformity of the product.

[0019] Preferably, the solvent is any one or a combination of N,N'-dimethylformamide, N,N'-dimethylacetamide and N-methylpyrrolidone.

[0020] By adopting the above technical solution, N,N'-dimethylformamide, N,N'-dimethylacetamide and N-methylpyrrolidone have good solubility properties and can effectively disperse raw materials such as pyromellitic dianhydride and 4,4'-diaminodiphenyl ether, ensuring the uniformity of the polyamide solution.

[0021] In a second aspect, the present application provides a method for preparing a high dielectric constant and high performance film for semiconductors, using the following technical solution: A method for preparing a high dielectric constant and high performance film for semiconductors, comprising the following steps: S1, adding pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, carbon nanotubes, a solvent, a flexibilizer and a catalyst into a reaction device, and reacting to obtain a polyamide solution; S2. The polyamide solution is cast on the surface of the substrate and the temperature is increased to carry out imidization reaction to obtain a high dielectric constant and high performance film for semiconductors.

[0022] Using the above technical solution, the preparation method first mixes pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, modified carbon nanotubes, a solvent, a flexibilizer, and a catalyst to form a polyamide solution. This process leverages the synergistic effects of the raw materials to ensure a uniform and stable solution, providing a foundation for subsequent film formation. Subsequently, the polyamide solution is cast onto a substrate surface and subjected to an imidization reaction, resulting in a high-dielectric-constant, high-performance film with excellent mechanical and heat resistance.

[0023] Preferably, the reaction temperature in step S1 is 160-180°C, and the temperature in step S2 is 280-300°C.

[0024] By adopting the above technical solution and controlling the reaction temperature within the range of 160-180°C, the polymerization reaction between pyromellitic dianhydride and 4,4'-diaminodiphenyl ether can be effectively promoted, improving the reaction efficiency of the polyamide solution, thereby ensuring the structural stability and mechanical strength of the high-performance membrane. Simultaneously, controlling the imidization reaction temperature within the range of 280-300°C can further optimize the film-forming properties of the polyimide, reduce the occurrence of side reactions, and enhance the heat resistance and dielectric properties of the high-performance membrane. The resulting high-dielectric-constant, high-performance membrane exhibits enhanced flexibility and long-term stability.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The high dielectric constant and high performance film for semiconductors of the present application is prepared by introducing carbon nanotubes and a specific proportion of pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, a solvent, a flexibilizer and a catalyst to prepare a high performance film, which significantly enhances the mechanical strength and flexibility of the high performance film, so that it can effectively avoid irreversible deformation and bending problems in thin and light flexible semiconductor chip packaging. It has a high dielectric constant and is suitable for thin and light flexible semiconductor chip packaging.

[0026] 2. The synergistic effect of modified carbon nanotubes and the flexibilizer improves the interfacial bonding performance of the film. The resulting film has good flexibility and dielectric properties, and is not easy to separate when used for a long time in a high-temperature environment. The flexibilizer is composed of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis(p-aminobenzoate), which can maintain the high strength of the film while giving it good bending stress resistance.

[0027] 3. The preparation process of the present application is to first mix and react pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, modified carbon nanotubes, a solvent, a flexibilizer and a catalyst to form a polyamide solution, and then cast the polyamide solution on the surface of the substrate and carry out an imidization reaction. The obtained high dielectric constant and high performance film has good flexibility, flatness and long-term stability. DETAILED DESCRIPTION

[0028] The present application is further described in detail below with reference to the embodiments.

[0029] The following are the sources and specifications of some raw materials of this application. The raw materials used in the preparation examples and examples of this application can be obtained from commercial sources, including but not limited to the following models and manufacturers. Raw materials with equivalent performance can be used: 1. Bisamino functional silane: Momentive A-1120 coupling agent; 2. Trihydroxy polyoxypropylene ether: Sea stone flower, CAS No. 25791-96-2, content 99%; 3. Polymethyl vinyl ether / maleic anhydride copolymer: Shuer, CAS No. 9011-16-9, content 99%; 4. Polytetramethylene ether glycol bis-p-aminobenzoate: Xingyan, CAS No. 54667-43-5, content 99%; 5. Carbon nanotubes: Double-walled carbon nanotubes, diameter 1-2nm, length 0.5-2μm.

[0030] Preparation example of modified carbon nanotubes Preparation Example 1 Preparation Example 1 discloses a modified carbon nanotube, which is prepared by the following steps: A1. Add 2 kg of carbon nanotubes to 1 kg of 50 wt% ethanol aqueous solution, then add 0.02 kg of bisamino-functional silane and 0.05 kg of trihydroxy polyoxypropylene ether, heat to 60° C., stir for 45 minutes, and filter to obtain pretreated carbon nanotubes; A2. Add 0.04 kg of dodecyl glycidyl ether as a long-chain alkyl glycidyl ether to the pretreated carbon nanotubes, knead and disperse at a temperature of 180° C. for 60 minutes to obtain modified carbon nanotubes.

[0031] Preparation Example 2-3 The difference between Preparation Example 2-3 and Preparation Example 1 is that the amount of raw materials used and the preparation conditions are different. Please refer to Table 1 below for details.

[0032] Table 1 Parameters of Preparation Examples 1-3 Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that an equal amount of long-chain alkyl glycidyl ether is replaced by butyl glycidyl ether, and the rest is the same as Preparation Example 1.

[0033] Preparation Example 5 The difference between Preparation Example 6 and Preparation Example 1 is that the bisamino-functional silane is replaced by vinyltrimethoxysilane in equal amounts, and the other steps are the same as Preparation Example 1.

[0034] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 1 is that an equal amount of trihydroxy polyoxypropylene ether is replaced by bisamino functional silane, and the other steps are the same as Preparation Example 1. Example

[0035] Example 1 Example 1 discloses a high dielectric constant and high performance film for semiconductors, which is prepared by the following steps: S1, adding 3.5 kg of pyromellitic dianhydride, 3 kg of 4,4'-diaminodiphenyl ether, 2 kg of commercially available carbon nanotubes, 5 kg of solvent, 0.5 kg of a flexibilizer (composed of a polymethyl vinyl ether / maleic anhydride copolymer and octaaminophenyl silsesquioxane in a weight ratio of 1:1) and 0.05 kg of triethylamine as a catalyst into a reactor, and reacting at a temperature of 160° C. for 3 h to obtain a polyamide solution; S2. The polyamide solution is cast on the surface of the substrate and subjected to imidization reaction at a temperature of 300° C. for 20 minutes to obtain a high dielectric constant and high performance film for semiconductors. The thickness of the film obtained in this embodiment is 12.5 μm.

[0036] Example 2-3 The difference between Example 2-3 and Example 1 is that the amount of raw materials used and the preparation conditions are different, see Table 2 below for details.

[0037] Table 2 Parameters of Examples 1-3 Examples 4-9 The difference between Examples 4-9 and Example 1 is that the sources of carbon nanotubes are different, see Table 3 below for details.

[0038] Table 3 Sources of carbon nanotubes Example Sources of carbon nanotubes Example 4 Preparation Example 1 Example 5 Preparation Example 2 Example 6 Preparation Example 3 Example 7 Preparation Example 4 Example 8 Preparation Example 5 Example 9 Preparation Example 6 Example 10 The difference between Example 10 and Example 4 is that the flexibilizer is composed of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate in a weight ratio of 1:2. The other components are the same as those in Example 4.

[0039] Example 11 The difference between Example 11 and Example 4 is that the flexibilizer is composed of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate in a weight ratio of 1:4, and the rest is the same as Example 4.

[0040] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the flexibilizer is replaced by 4,4'-diaminodiphenyl ether in equal amount, and the other components are the same as those in Example 1.

[0041] Performance testing The following performance tests were conducted on the high dielectric constant and high performance films for semiconductors prepared in Examples 1-11 and Comparative Example 1: 1. Dielectric constant test Refer to the test method in ASTM D150 and use a dielectric constant tester to test the dielectric constant of the film. Test conditions: 1KHz; 2. Elongation at break test According to the test method in ASTM D3039, the elongation at break of the film was tested (unit: %); 3. Fit stability performance test The film was attached to a 4-inch flexible semiconductor chip and placed in a constant temperature box at a temperature of 85°C and a humidity of 85% for 7 days. After removal, the edge area was observed for separation, and the test results were recorded.

[0042] The following are the performance test data of the high dielectric constant and high performance films for semiconductors of Examples 1-11 and Comparative Example 1. For details, see Table 4 below.

[0043] Table 4 Data of high dielectric constant and high performance films for semiconductors of Examples 1-11 and Comparative Example 1 In combination with Examples 1-3 and 4-9 and in combination with Table 4, it can be concluded that the modified carbon nanotubes of the present application are compounded with the system, and the obtained film has a higher dielectric constant while also having good flexibility and fitting stability. Compared with Example 1, Example 4-6 replaces the commercially available carbon nanotubes with the modified carbon nanotubes obtained in this application. The dielectric constant is improved while the elongation at break is improved. This may be because the dispersion and compatibility of the modified carbon nanotubes in the system are improved, which improves the flexibility of the obtained film. Compared with Example 4, Examples 7-9 change the compounding types of the diamino-type functional silane, trihydroxy polyoxypropylene ether and long-chain alkyl glycidyl ether in the modified carbon nanotubes. The dielectric constant and elongation at break of the obtained film are reduced, and the problem of film separation occurs after the wet heat test.

[0044] Combining Example 4 and Examples 10-11, Comparative Example 1 and Table 4, it can be concluded that the use of the preferred weight of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate of the present application as a flexibilizer can improve the flexibility of the film while also slightly increasing the dielectric constant of the film. In Comparative Example 1, the flexibilizer is replaced with 4,4'-diaminodiphenyl ether, and the elongation at break of the obtained film is reduced, and the dielectric constant is also slightly reduced.

[0045] From the above analysis, it can be concluded that the dielectric constant of the film used in this application can reach up to 4.32, the elongation at break can reach 255%, and it has good bonding stability after the wet heat test, and is suitable for lightweight and flexible semiconductor chip packaging.

[0046] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high dielectric constant and high performance film for semiconductors, characterized in that: It is prepared from the following raw materials in parts by weight: 35-45 parts of pyromellitic dianhydride 30-40 parts of 4,4'-diaminodiphenyl ether 20-30 parts of carbon nanotubes 50-70 parts solvent 5-8 parts of flexibilizer 0.5-1.5 parts of catalyst.

2. The high dielectric constant and high performance film for semiconductors according to claim 1, characterized in that: The carbon nanotubes are modified carbon nanotubes, which are prepared by the following steps: A1. Add 20-30 parts of carbon nanotubes to 10-20 parts of ethanol aqueous solution, then add 0.2-0.4 parts of bisamino functional silane and 0.3-0.5 parts of trihydroxy polyoxypropylene ether, heat and stir, and filter to obtain pretreated carbon nanotubes; A2. Add 0.4-0.8 parts of long-chain alkyl glycidyl ether to the pretreated carbon nanotubes, knead and disperse, and prepare modified carbon nanotubes.

3. The high dielectric constant and high performance film for semiconductors according to claim 2, characterized in that: The long-chain alkyl glycidyl ether in step A2 is a carbon 12- to carbon 18-alkyl glycidyl ether.

4. The high dielectric constant and high performance film for semiconductors according to claim 2, characterized in that: The stirring temperature in the step A1 is 60-70°C, and the kneading temperature in the step A2 is 180-200°C.

5. The high dielectric constant and high performance film for semiconductors according to claim 1, characterized in that: The carbon nanotubes are double-walled carbon nanotubes with a diameter of 1-2 nm and a length of 0.5-2 μm.

6. The high dielectric constant and high performance film for semiconductors according to claim 1, characterized in that: The flexibilizer consists of polymethyl vinyl ether / maleic anhydride copolymer and polytetramethylene ether glycol bis-p-aminobenzoate in a weight ratio of 1:(2-4).

7. The high dielectric constant and high performance film for semiconductors according to claim 1, characterized in that: The catalyst is any one or a combination of diethylamine, triethylamine, triethylenediamine, N,N'-diethylpiperazine and N,N'-diethyl-2-methylpiperazine.

8. The high dielectric constant and high performance film for semiconductors according to claim 1, characterized in that: The solvent is any one or a combination of N,N'-dimethylformamide, N,N'-dimethylacetamide and N-methylpyrrolidone.

9. A method for preparing a high dielectric constant and high performance film for semiconductors according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1, adding pyromellitic dianhydride, 4,4'-diaminodiphenyl ether, carbon nanotubes, a solvent, a flexibilizer and a catalyst into a reaction device, and reacting to obtain a polyamide solution; S2. The polyamide solution is cast on the surface of the substrate and the temperature is increased to carry out imidization reaction to obtain a high dielectric constant and high performance film for semiconductors.

10. The method for preparing a high dielectric constant and high performance film for semiconductors according to claim 9, characterized in that: The reaction temperature in step S1 is 160-180°C, and the temperature in step S2 is 280-300°C.

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