A solder resist dry film with low thermal expansion coefficient and its application

Abstract

This application relates to a low coefficient of thermal expansion solder resist dry film, the raw materials of which include: by weight, 10-20 parts of high elastic polymer, 30-45 parts of epoxy resin, 1-2 parts of defoamer, 0.3-0.8 parts of thermosetting agent, 0.05-0.1 parts of curing accelerator, 40-60 parts of inorganic filler, 13-16 parts of difunctional acrylate monomer, 10-15 parts of flame retardant, 3-5 parts of colorant, and 8-15 parts of solvent; by designing the types, structure and content of polymerizable materials in the solder resist dry film, the solder resist dry film has good flexibility, flame retardancy, corrosion resistance and processing fluidity, and especially has a low coefficient of thermal expansion, which can resist cracking caused by high temperature stress. The prepared solder resist dry film can be used on IC carrier boards.

Description

Technical Field

[0001] This invention relates to the field of electronic packaging technology, specifically a low thermal expansion coefficient solder resist dry film and its application. Background Technology

[0002] As technology places ever-increasing demands on the precision, reliability, and portability of various electronic instruments, military equipment, and computers, the requirements for their manufacturing processes are becoming increasingly stringent. Generally, printed circuit boards used in electronic devices, such as integrated circuits, typically have a solder resist layer formed on the circuit substrate, excluding the interconnect holes, to prevent the conductors from being exposed and corroded by oxidation and humidity. Currently, using solder resist to form the solder resist layer has become the mainstream technology. This technology involves coating a photosensitive resin onto the substrate, forming a pattern through exposure and development, and then using heat and / or light irradiation to completely cure the resin.

[0003] Although dry film solder resist has better reliability, existing dry film solder resist also has some problems in use. For example, existing dry film solder resist may crack when subjected to thermal stress, has poor thermal shock resistance, and is prone to warping, deformation, or even delamination after being subjected to high and low temperature environments. This can easily lead to a decrease in the yield of circuit boards and seriously restrict its practical use in the fields of flexible printed circuits and flexible optoelectronic displays.

[0004] Patent CN202210223873.3 discloses a dry film photoresist for solder resist, its preparation method, and its application. The photoresist film is designed as a three-layer structure, and the solid acid value of the acrylate main resin in the multilayer structure photoresist layer increases sequentially from bottom to top. Although the corrosion resistance of the solder resist dry film is increased by increasing the different acid values, the solder resist dry film is prone to stress cracking due to the difference in mechanical properties between each layer. Patent CN200680003673.6 discloses a positive dry film photoresist and a composition for preparing the photoresist. The composition exhibits good photosensitivity, resolution, and adhesion to the substrate. However, its dry film has insufficient high temperature resistance and flexibility, making it unsuitable as a cover film for circuit boards, let alone a solder resist layer for high-precision circuit boards. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention first provides a solder resist dry film with a low coefficient of thermal expansion. The raw materials for preparing the solder resist dry film include, by weight, 10-20 parts of a high-elasticity polymer, 30-45 parts of epoxy resin, 1-2 parts of defoamer, 0.3-0.8 parts of thermosetting agent, 0.05-0.1 parts of curing accelerator, 40-60 parts of inorganic filler, 13-16 parts of difunctional acrylate monomer, 10-15 parts of flame retardant, 3-5 parts of colorant, and 8-15 parts of solvent.

[0006] Furthermore, the raw materials for preparing the highly elastic polymer include: amino-substituted aromatic compounds, acrylic acid, acrylate monomers, isocyanates, and N-methylpyrrolidone.

[0007] Furthermore, the raw materials for preparing the high-elasticity polymer include, by weight, 10-20 parts of amino-substituted aromatic compounds, 20-25 parts of acrylic acid, 5-15 parts of acrylate monomers, 1-3 parts of isocyanate, and 6-12 parts of N-methylpyrrolidone.

[0008] Furthermore, the amino-substituted aromatic compound is selected from one or more of p-phenylenediamine, o-phenylenediamine, m-phenylenediamine, benzidine, and aminophenylalkanes.

[0009] Furthermore, the amino-substituted aromatic compound is selected from one or more of p-phenylenediamine, m-phenylenediamine, 4,4'-biphenylenediamine, 3,3'-diethyl-4,4'-diaminobiphenyl, 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, and 3,3'-diethyl-4,4'-diaminodiphenylmethane.

[0010] Furthermore, the acrylate monomers are selected from C3-C10 alkyl-substituted acrylates, hydroxy-substituted acrylates, polyester acrylates, and silicone-containing acrylates.

[0011] Furthermore, the acrylate monomers are silicone-containing acrylates. In the technical solution of this application, acrylate monomers can increase the crosslinking degree of the system during photosensitive development, but in this system, they are mainly used to provide flexible segments to suppress cracking of the dry film under high-temperature stress. The applicant unexpectedly discovered that when silicone-containing acrylates are used, the prepared solder resist dry film has better high-temperature crack resistance and better uniformity. The applicant analyzed the reasons as follows: the -Si-O bonds in silicone-containing acrylates are easy to flip, have good heat resistance, and have good lubrication and fluidity. When the solder resist dry film of this system is subjected to high-temperature mechanical impact, the expansion of the internal molecular chains can effectively reduce the stress generated in the system and suppress the generation of cracks. The prepared solder resist dry film has a small coefficient of thermal expansion.

[0012] Furthermore, the acrylate monomer is selected from at least one of 3-(triethoxysilyl)propyl methacrylate, 3-(diethoxymethylsilyl)propyl methacrylate, trimethylsilyl methyl acrylate, and 3-trimethylsilylpropynyl methacrylate.

[0013] In a preferred embodiment, the acrylate monomer is trimethylsilyl methacrylate.

[0014] Furthermore, the total weight ratio of the acrylic acid and acrylate monomers to the total weight of the amino-substituted aromatic compounds is 1:(0.3-0.6); the flexibility and cross-linking degree of the high-elasticity polymer are adjusted by regulating the relative content of different monomers.

[0015] In its experiments, the applicant discovered that amino-substituted aromatic compounds can enhance the cohesive force of the polymer through cross-linking and entanglement with other molecular chains and their own large steric rotational resistance, thus providing higher hardness and aging resistance to the solder resist dry film. However, when the addition amount exceeds a certain range, the viscosity of the highly elastic polymer will increase significantly, which is detrimental to the processing fluidity. Furthermore, when used as a dry film solder resist layer, thermal stress will cause minor cracks. However, when acrylic acid and acrylate monomers are added in relatively large quantities, the alkali resistance of the solder resist dry film is improved during the development process. But because the film components are too fluid during the coating process, there is a risk of uneven coating of the solder resist dry film, which requires a high level of skill in the coating process.

[0016] In a preferred embodiment, when the total weight ratio of the acrylic acid and acrylate monomers to the total weight of the amino-substituted aromatic compounds is 1:0.5, the prepared solder resist dry film exhibits the least degree of thermal shock cracking and curling, and the lowest coefficient of thermal expansion of the dry film.

[0017] Furthermore, the preparation method of the highly elastic polymer is as follows: accurately weigh the amino-substituted aromatic compound, acrylic acid, acrylate monomer, isocyanate, and N-methylpyrrolidone, mix the above materials, and react at 50-100℃ for 3-6 hours.

[0018] Furthermore, the epoxy resin is selected from at least one of phenolic epoxy resin, bisphenol A epoxy resin, brominated bisphenol A type epoxy resin, and bisphenol S type epoxy resin.

[0019] Furthermore, the present invention does not impose strict limitations on defoamers, but preferably uses polyether-based defoamers.

[0020] Furthermore, the flame retardant is selected from at least one of silicon-based flame retardants, phosphorus-based flame retardants, nitrogen-containing and phosphorus-containing flame retardants, and inorganic flame retardants.

[0021] Furthermore, the flame retardant is a compound of nitrogen- and phosphorus-containing flame retardants and inorganic flame retardants.

[0022] Furthermore, the compound weight ratio of the nitrogen-containing and phosphorus-containing flame retardant to the inorganic flame retardant is (3-6):(4-12). The inorganic flame retardant is in the form of solid particles. If too much is added, it will reduce the compatibility of the system and the adhesion of the dry film to the IC substrate. The compounding of the organic nitrogen-containing and phosphorus-containing flame retardant reduces the content of solid particles in the dry film and improves the flame retardant performance. However, if too much is added, it will affect the uniformity of the dry film during coating.

[0023] Furthermore, the nitrogen- and phosphorus-containing flame retardant is selected from one or a combination of several of DOPO, BPPAPO, PETBP, and ODDP.

[0024] Preferably, the nitrogen- and phosphorus-containing flame retardant is DOPO.

[0025] Furthermore, the inorganic flame retardant is selected from one or a combination of several of aluminum hydroxide, magnesium hydroxide, zinc borate, and ammonium polyphosphate.

[0026] Preferably, the inorganic flame retardant is aluminum hydroxide with an average particle diameter of 7-9 μm.

[0027] Furthermore, the inorganic filler comprises materials with a thermal expansion coefficient of (0-10)×10⁻⁶. -6 The inorganic filler of / K is selected from one or more of the following: silicon dioxide, aluminum oxide, boron nitride, titanium dioxide, zinc oxide, silicon nitride, silicon carbide, boron nitride, mullite, spinel, and chalcogenide.

[0028] Preferably, the coefficient of thermal expansion is (0-10)×10⁻¹⁰. -6 The inorganic filler of / K is a compound of alumina and silicon nitride with a weight ratio of (1-3):(3-5). Silicon nitride has a high thermal conductivity, which can effectively transfer the local high temperature of the solder resist dry film and improve the high temperature resistance of the dry film.

[0029] Preferably, the average particle diameter of the alumina is 1-1.5 μm.

[0030] Preferably, the average particle diameter of the silicon nitride is 200-400 nm.

[0031] Furthermore, the inorganic filler also includes at least one of the substances with the general formula AM2O7 or AM2O8, wherein A is selected from Ti, Sn, and Zr, and M is selected from W, V, P, and Mo.

[0032] Furthermore, the substance with the general formula AM2O7 or AM2O8 is selected from one or a combination of zirconium tungstate, zirconium vanadate, and zirconium molybdate.

[0033] In a preferred embodiment, the substance with the general formula AM2O7 or AM2O8 is zirconium tungstate, with an average particle diameter of 500-800 nm.

[0034] Furthermore, the coefficient of thermal expansion is (0-10)×10⁻¹⁰. -6 The weight ratio of the inorganic filler and the substance with the general formula AM2O7 or AM2O8 in / K is (5-8):1. This application found in its research that by using a compound of the two, the coefficient of thermal expansion of the solder resist dry film of this application can be effectively reduced, using only a coefficient of thermal expansion of (0-10)×10.-6 When adding inorganic fillers, increasing their amount can suppress high-temperature cracking of the solder resist dry film to some extent, but this suppression is far from sufficient. Moreover, when the amount added is too high, the system compatibility decreases, the uniformity of the dry film deteriorates, and the adhesion to the IC substrate also decreases. By adding inorganic fillers with negative thermal expansion coefficients, the amount of inorganic fillers added can be effectively reduced, but excessive addition will cause the dry film to twist when heated.

[0035] Furthermore, the thermosetting agent is selected from at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, diglycidyl phthalate, silane-modified epoxy resin, and isocyanate substances.

[0036] Preferably, the thermosetting agent is an isocyanate.

[0037] Preferably, the isocyanate is a diisocyanate.

[0038] Furthermore, the curing accelerator is selected from one of phenylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole.

[0039] Furthermore, the difunctional acrylate monomer is selected from one or more of dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol acrylate, neopentyl glycol diacrylate, and 2-ethoxy-1,6-hexanediol diacrylate.

[0040] Furthermore, the bifunctional acrylate monomer is one of dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, and 1,4-butanediol acrylate.

[0041] Furthermore, the colorant is a conventional colorant used in the industry, and this application does not impose any special limitations on it.

[0042] Furthermore, the solvent is selected from at least one of ethyl acetate, butyl acetate, ethanol, methyl ethyl ketone, acetone, cyclohexanone, xylene, and ethylene glycol monoethyl ether acetate.

[0043] Preferably, the solvent is methyl ethyl ketone and ethylene glycol monoethyl ether acetate in a weight ratio of 1:(1-3).

[0044] Furthermore, the method for preparing the solder resist dry film is as follows:

[0045] S1. Mix the above-mentioned raw materials for solder resist dry film and stir evenly to form a mixture;

[0046] S2. Use a comma coating machine to coat the mixture onto the polyester carrier film, bake it in a drying oven at 60-85℃ for 5-20 minutes, and the dry film thickness is 30-75μm. Then use a laminating machine to apply the release protective film onto the adhesive layer.

[0047] Secondly, the present invention also provides an application of a low thermal expansion coefficient solder resist dry film on an IC substrate.

[0048] Furthermore, the uniformity of the copper plating on the IC substrate is ≥90%.

[0049] Beneficial effects

[0050] 1. This application designs the types, structure and content of polymerizable materials in the solder resist dry film to make the solder resist dry film have good flexibility, flame retardancy and processing fluidity, and can resist cracking caused by high temperature stress. The prepared solder resist dry film can be used on IC carrier boards.

[0051] 2. This application designs the types and contents of monomers of highly elastic polymers, so that the prepared solder resist dry film has good molecular chain extensibility, which not only improves the film-forming performance of the dry film, but also effectively reduces the warping and cracking of the dry film.

[0052] 3. This application reduces the content of solid particulate matter in the dry film by compounding inorganic fillers with different coefficients of thermal expansion, improves the adhesion between the dry film and the carrier plate, and effectively reduces the coefficient of thermal expansion of the solder resist dry film.

[0053] 4. By compounding different flame retardants and limiting the particle size of the flame retardants, this application improves the density and corrosion resistance of the dry film, giving the solder resist dry film of this application good flame retardant properties and salt spray resistance. Detailed Implementation

[0054] Example

[0055] Example 1:

[0056] A low thermal expansion coefficient solder resist dry film is prepared from the following raw materials: by weight, 15 parts of high elastic polymer, 38 parts of epoxy resin, 1.5 parts of defoamer, 0.5 parts of thermosetting agent, 0.08 parts of curing accelerator, 50 parts of inorganic filler, 15 parts of difunctional acrylate monomer, 12 parts of flame retardant, 4 parts of colorant, and 12 parts of solvent.

[0057] The epoxy resin is phenolic epoxy resin (NPPN-638, brand: Nanya, viscosity at 23℃: 23000mPas), the defoamer is a polyether defoamer (DF-1851, brand: Defeng), the thermosetting agent is diisocyanate, the curing accelerator is 2-methylimidazole, and the inorganic filler consists of 14 parts alumina (average particle diameter: 1.2μm), 29 parts silicon nitride (average particle diameter: 3000nm), and 7 parts zirconium tungstate (average particle diameter: 650nm); the double... The functional acrylate monomer is 1,6-hexanediol diacrylate; the flame retardant is a compound of nitrogen-containing and phosphorus-containing flame retardant and inorganic flame retardant in a weight ratio of 5:8, the nitrogen-containing and phosphorus-containing flame retardant is DOPO (CAS: 35948-25-5), the inorganic flame retardant is aluminum hydroxide (Jinan Jinyingtai Chemical Co., Ltd., YT1305), and the average particle diameter is 7-9μm; the colorant is Pigment Yellow G180, and the solvent is a combination of ethylene glycol monoethyl ether acetate and methyl ethyl ketone in a mass ratio of 1:2.

[0058] The preparation method of the high elastic polymer is as follows: accurately weigh 17 parts of 4,4'-biphenyldiamine, 22 parts of acrylic acid, 12 parts of trimethylsilyl methacrylate, 1.5 parts of isocyanate, and 10 parts of N-methylpyrrolidone by weight, mix the above materials and react at 75°C for 5 hours.

[0059] The method for preparing the solder resist dry film is as follows:

[0060] S1. Mix the above-mentioned raw materials for solder resist dry film and stir evenly to form a mixture;

[0061] S2. Use a comma coating machine to coat the mixture onto the polyester carrier film, bake it in an 80°C drying oven for 10 minutes until the dry film thickness is 50μm, and then use a laminating machine to apply the PE release protective film onto the adhesive layer.

[0062] Example 2

[0063] A low thermal expansion coefficient solder resist dry film is prepared from the following raw materials: by weight, 10 parts of high elastic polymer, 30 parts of epoxy resin, 1 part of defoamer, 0.3 parts of thermosetting agent, 0.05 parts of curing accelerator, 60 parts of inorganic filler, 16 parts of difunctional acrylate monomer, 15 parts of flame retardant, 3 parts of colorant, and 8 parts of solvent.

[0064] The epoxy resin is phenolic epoxy resin (NPPN-638, brand: Nan Ya, viscosity at 23℃: 23000 mPas), the defoamer is a polyether defoamer (DF-1851, brand: De Feng), the thermosetting agent is diisocyanate, the curing accelerator is 2-methylimidazole, and the inorganic filler is 25 parts alumina (average particle diameter: 1 μm), 25 parts silicon nitride (average particle diameter: 200 nm), and 10 parts zirconium tungstate (average particle diameter: 800 nm). The bifunctional acrylate monomer is 1,6-hexanediol diacrylate; the flame retardant is a compound of nitrogen-containing and phosphorus-containing flame retardant and inorganic flame retardant in a weight ratio of 6:4, the nitrogen-containing and phosphorus-containing flame retardant is DOPO (CAS: 35948-25-5), the inorganic flame retardant is aluminum hydroxide (Jinan Jinyingtai Chemical Co., Ltd., YT1305), and the average particle diameter is 7μm; the colorant is Pigment Yellow G180, and the solvent is a combination of ethylene glycol monoethyl ether acetate and methyl ethyl ketone in a mass ratio of 1:1.

[0065] The preparation method of the high elastic polymer is as follows: accurately weigh 20 parts of 4,4'-biphenyldiamine, 20 parts of acrylic acid, 15 parts of trimethylsilyl methacrylate, 3 parts of isocyanate, and 12 parts of N-methylpyrrolidone by weight, mix the above materials and react at 100°C for 4 hours.

[0066] The method for preparing the solder resist dry film is as follows:

[0067] S1. Mix the above-mentioned raw materials for solder resist dry film and stir evenly to form a mixture;

[0068] S2. Use a comma coating machine to coat the mixture onto the polyester carrier film, bake it in a drying oven at 65°C for 15 minutes until the dry film thickness is 75μm, and then use a laminating machine to apply the PE release protective film onto the adhesive layer.

[0069] Example 3

[0070] A low thermal expansion coefficient solder resist dry film is prepared from the following raw materials: by weight, 20 parts of high elastic polymer, 45 parts of epoxy resin, 2 parts of defoamer, 0.8 parts of thermosetting agent, 0.1 parts of curing accelerator, 40 parts of inorganic filler, 13 parts of difunctional acrylate monomer, 10 parts of flame retardant, 5 parts of colorant, and 15 parts of solvent.

[0071] The epoxy resin is phenolic epoxy resin (NPPN-638, brand: Nanya, viscosity at 23℃: 23000mPas), the defoamer is a polyether defoamer (DF-1851, brand: Defeng), the thermosetting agent is diisocyanate, the curing accelerator is 2-methylimidazole, and the inorganic filler is 6 parts alumina (average particle diameter: 1.5μm), 30 parts silicon nitride (average particle diameter: 400nm), and 4 parts zirconium tungstate (average particle diameter: 500nm). The bifunctional acrylate monomer is 1,6-hexanediol diacrylate; the flame retardant is a compound of nitrogen-containing and phosphorus-containing flame retardant and inorganic flame retardant in a weight ratio of 1:4, the nitrogen-containing and phosphorus-containing flame retardant is DOPO (CAS: 35948-25-5), the inorganic flame retardant is aluminum hydroxide (Jinan Jinyingtai Chemical Co., Ltd., YT1305), and the average particle diameter is 9μm; the colorant is Pigment Yellow G180, and the solvent is a combination of ethylene glycol monoethyl ether acetate and methyl ethyl ketone in a mass ratio of 1:3.

[0072] The preparation method of the high elastic polymer is as follows: accurately weigh 10 parts of 4,4'-biphenyldiamine, 25 parts of acrylic acid, 8 parts of trimethylsilyl methacrylate, 1 part of isocyanate, and 6 parts of N-methylpyrrolidone by weight, mix the above materials and react at 60°C for 6 hours.

[0073] The method for preparing the solder resist dry film is as follows:

[0074] S1. Mix the above-mentioned raw materials for solder resist dry film and stir evenly to form a mixture;

[0075] S2. Use a comma coating machine to coat the mixture onto the polyester carrier film, bake it in a drying oven at 70°C for 8 minutes, and the dry film thickness is 30μm. Then use a laminating machine to apply the PE release protective film onto the adhesive layer.

[0076] Comparative Example 1

[0077] Same as Example 1, except that: the preparation method of the high elastic polymer is as follows: accurately weigh 30 parts of 4,4'-biphenyldiamine, 22 parts of acrylic acid, 12 parts of trimethylsilyl methacrylate, 1.5 parts of isocyanate, and 10 parts of N-methylpyrrolidone by weight, mix the above materials and react at 75°C for 5 hours.

[0078] Comparative Example 2

[0079] Same as Example 1, except that the acrylate monomer is 3-hydroxypropyl acrylate, purchased from Hubei Xinhongli Chemical Co., Ltd.

[0080] Comparative Example 3

[0081] Same as Example 1, except that: the inorganic filler is 20 parts alumina with an average particle diameter of 1.2 μm, 30 parts silicon nitride with an average particle diameter of 3000 nm, and 5 parts zirconium tungstate with an average particle diameter of 650 nm.

[0082] Performance testing methods:

[0083] The prepared dry film was laminated onto a copper-clad laminate (copper foil thickness 12 μm, copper plating uniformity approximately 93%) with surface-treated polyimide as the substrate using a laminator, and then exposed to 400 mJ / cm² using a 7 kW exposure machine. 2 After exposure, the sample was developed by immersing it in an alkaline solution of 1 wt% Na2CO3 at 30°C for 60 seconds, and then cured at 150°C for 1 hour. Salt spray resistance, warpage, and coefficient of thermal expansion were then tested on the sample.

[0084] 1. Salt spray resistance test: The test plate obtained in the above example was placed in a NaCl aqueous solution (5wt%) at 35℃, and the dry film was observed to see if it peeled off after 96h.

[0085] 2. Warpage: A sample made from the solder resist dry film of the embodiment was cut into 50×50mm pieces, and the average warpage of the four corners was measured. The evaluation criteria were as follows:

[0086] A: Warpage is 0-3mm;

[0087] B: Warpage is greater than 3mm but less than 5mm;

[0088] C: Warpage is 5mm or more.

[0089] 3. Coefficient of thermal expansion: The coefficient of thermal expansion of the solder resist dry film in the example was measured at 25-150℃.

[0090] The test results of the examples are shown in Table 1.

[0091] Performance test results:

[0092] Table 1

[0093]

Claims

1. A solder resist dry film with a low coefficient of thermal expansion, characterized in that the raw materials for preparing the solder resist dry film include: By weight, the composition includes 10-20 parts of high-elasticity polymer, 30-45 parts of epoxy resin, 1-2 parts of defoamer, 0.3-0.8 parts of thermosetting agent, 0.05-0.1 parts of curing accelerator, 40-60 parts of inorganic filler, 13-16 parts of difunctional acrylate monomer, 10-15 parts of flame retardant, 3-5 parts of colorant, and 8-15 parts of solvent. The raw materials for preparing the high elastic polymer include, by weight, 10-20 parts of amino-substituted aromatic compounds, 20-25 parts of acrylic acid, 5-15 parts of acrylate monomers, 1-3 parts of isocyanate, and 6-12 parts of N-methylpyrrolidone. The flame retardant is a compound of nitrogen-containing and phosphorus-containing flame retardants and inorganic flame retardants. The inorganic flame retardant is selected from one or more of aluminum hydroxide, magnesium hydroxide, zinc borate, and ammonium polyphosphate. The inorganic filler comprises materials with a thermal expansion coefficient of (0-10)×10. -6 / K inorganic filler; the coefficient of thermal expansion is (0-10)×10 -6 The inorganic filler of / K is a mixture of alumina and silicon nitride; The inorganic filler also includes at least one of the substances with the general formula AM2O7 or AM2O8; The alumina has an average particle diameter of 1-1.5 μm; the silicon nitride has an average particle diameter of 200-400 nm. In the general formula AM2O7 or AM2O8, A is selected from Ti, Sn, and Zr, and M is selected from W, V, P, and Mo.

2. The solder resist dry film with a low coefficient of thermal expansion according to claim 1, characterized in that the total weight ratio of the acrylic acid and acrylate monomers to the total weight of the amino-substituted aromatic compounds is 1:(0.3-0.8).

3. The solder resist dry film with a low coefficient of thermal expansion according to claim 2, characterized in that the acrylate monomer is selected from C3-C10 alkyl-substituted acrylates, hydroxy-substituted acrylates, polyester acrylates, and silicone-containing acrylates.

4. The solder resist dry film with a low coefficient of thermal expansion according to claim 3, characterized in that the acrylate monomer is a silicone-containing acrylate.

5. The solder resist dry film with low thermal expansion coefficient according to claim 1, characterized in that, when the substance with the general formula AM2O7 or AM2O8 is zirconium tungstate, the average particle diameter is 500-800 nm.

6. The solder resist dry film with a low coefficient of thermal expansion according to claim 5, characterized in that the coefficient of thermal expansion is (0-10)×10⁻⁶. -6 The weight ratio of the inorganic filler of / K to the substance with the general formula AM2O7 or AM2O8 is (5-8):

1.

7. The application of a low thermal expansion coefficient solder resist dry film according to any one of claims 1-6 on an IC substrate.

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