Epoxy resin composition and product thereof

Abstract

The invention discloses an epoxy resin composition and a product thereof, the epoxy resin composition comprises the following components: epoxy resin A, epoxy resin B and filler, the epoxy resin A is common epoxy resin; the epoxy resin B is modified liquid crystal epoxy resin, and the clearing point enthalpy of the epoxy resin B is changed into 2J / g-5J / g; the heat conductivity coefficient of the filler is greater than or equal to 12W / m.K. The modified liquid crystal epoxy resin is introduced into the common epoxy resin, the heat conductivity coefficient of the filler is limited, the clearing point enthalpy change of the modified liquid crystal epoxy resin is limited, and the orderliness of the modified liquid crystal epoxy resin is improved, so that the resin composition is applied to subsequent products; the heat conductivity coefficient and the breakdown strength of the product can be simultaneously improved.

Description

Technical Field

[0001] This invention belongs to the field of electronic materials technology, and particularly relates to an epoxy resin composition and its products. Background Technology

[0002] With the application of high-power devices and the miniaturization of equipment and the increase in operating voltage, the requirements for the thermal conductivity of insulating films and the breakdown strength of circuit boards subsequently made from insulating films are also increasing.

[0003] Currently, to improve the thermal conductivity of the insulating layer in insulating films, high thermal conductivity inorganic fillers such as alumina and boron nitride are filled into the epoxy resin matrix. However, the thermal conductivity still fails to meet application requirements. Existing technologies also improve the thermal conductivity of insulating films by adding liquid crystal epoxy resin to ordinary epoxy resin. However, this addition leads to the subsequent circuit board fabrication failing to meet the breakdown strength requirements of high-frequency, high-voltage applications. Therefore, existing insulating film technologies face the challenge of synergistically improving both high thermal conductivity and high breakdown strength. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide an epoxy resin composition and its products, wherein the products subsequently manufactured from the epoxy resin composition can simultaneously meet the performance requirements of high thermal conductivity and high breakdown strength.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An epoxy resin composition comprises the following components: epoxy resin A, epoxy resin B, and filler, wherein epoxy resin A is a common epoxy resin; epoxy resin B is a modified liquid crystal epoxy resin, the clearing point enthalpy change of epoxy resin B is 2J / g-5J / g; and the thermal conductivity of the filler is ≥12W / m·K.

[0007] The common epoxy resins include, but are not limited to, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin and alicyclic epoxy resin, which are epoxy resin matrices commonly used in current circuit boards.

[0008] The modified liquid crystal epoxy resin is a liquid crystal epoxy resin modified with functional groups. The liquid crystal epoxy resin is an epoxy resin containing mesocrystalline units. The mesocrystalline unit is a rigid core with a structure similar to Ph-Ph, Ph-X-Ph and Ph-X-Ph-X-Ph, where X is one of the structures -CH=N-, -N=N-, -N=N(O)- and -COO-, and Ph is a benzene ring structure. The liquid crystal epoxy resin exhibits a three-dimensional ordered solid crystal structure at room temperature and transforms into a partially ordered smectic phase or phase sequence structure when heated to 50~150℃.

[0009] Preferably, the molecular weight difference between epoxy resin B and epoxy resin A is ≥5000 g / mol.

[0010] Preferably, the epoxy resin A satisfies at least one of the following conditions:

[0011] (1) The molecular weight of the epoxy resin A is ≤1200g / mol;

[0012] (2) The epoxy value of the epoxy resin A is in the range of 0.20mol / 100g-0.55mol / 100g.

[0013] Preferably, the crosslinking density of the epoxy resin B is 60 mol / L-80 mol / L.

[0014] Preferably, the liquid crystal epoxy resin in epoxy resin B satisfies at least one of the following conditions:

[0015] (1) The molecular weight of the liquid crystal epoxy resin is 2000 g / mol-4000 g / mol;

[0016] (2) The epoxy value of the liquid crystal epoxy resin is 0.20mol / 100g-0.55mol / 100g.

[0017] Preferably, the epoxy resin B is a liquid crystal epoxy resin modified with a low-polarity compound, and the low-polarity compound satisfies at least one of the following conditions:

[0018] (1) The molecular weight of the low polar compound is 1000 g / mol to 2000 g / mol;

[0019] (2) The surface polarity of the low polarity compound is ≤3.0.

[0020] Preferably, the low-polarity compound is selected from one or more combinations of polyol compounds, polyamine compounds, siloxane compounds, and fluororesins.

[0021] Preferably, the low-polarity compound is a diol compound.

[0022] Preferably, the diol compound is selected from one or more combinations of aliphatic straight-chain diols, alicyclic diols, polyether diols, and polyolefin diols.

[0023] Preferably, based on 100 parts by weight of epoxy resin A, the amount of epoxy resin B is 100-235 parts by weight, and the amount of filler is 1000-2670 parts by weight.

[0024] An article using the epoxy resin composition described above, the article comprising an insulating film, a circuit board, and a printed circuit board.

[0025] The present invention, by adopting the above technical solution, has the following beneficial effects:

[0026] In this invention, a modified liquid crystal epoxy resin is introduced into a common epoxy resin, and the thermal conductivity of the filler is limited to give the resin composition a high thermal conductivity base. The orderliness of the modified liquid crystal epoxy resin is improved by limiting the enthalpy change at the clearing point. As a result, when this resin composition is used in subsequent products, it can simultaneously improve the thermal conductivity and breakdown strength of the products. Detailed Implementation

[0027] The embodiments of this application are described in detail below. The described embodiments are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] In this invention, except for the components specifically described for synthesis, all other components and reagents involved are conventional commercially available products or can be obtained through conventional technical means in the art. Unless otherwise stated, the materials, methods, and embodiments of this invention are exemplary only and not limiting.

[0029] This application provides an epoxy resin composition comprising the following components: epoxy resin A, epoxy resin B, and filler, wherein epoxy resin A is a common epoxy resin; epoxy resin B is a modified liquid crystal epoxy resin, the clearing point enthalpy change of epoxy resin B is 2J / g-5J / g; and the thermal conductivity of the filler is ≥12W / m·K.

[0030] The enthalpy change at the clearing point reflects the degree of order in the formation of the liquid crystal resin. In this invention, a larger enthalpy change at the clearing point indicates a higher degree of order in the liquid crystal epoxy resin, making electron transport easier and leading to a decrease in breakdown strength. In this invention, by limiting the thermal conductivity of the filler to ≥12W / m·K, a higher basic thermal conductivity is imparted to the subsequent product. By limiting the enthalpy change at the clearing point of the modified liquid crystal epoxy resin to 2J / g-5J / g, the thermal conductivity of the subsequent product is improved while preventing a decrease in breakdown strength.

[0031] The epoxy resin A includes, but is not limited to, one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, and alicyclic epoxy resin. It can also be other common epoxy resins or a combination of multiple common epoxy resins. For example, epoxy resin A includes, but is not limited to, 2,2-bis(4-epoxypropoxyphenyl)propane, bis(4-epoxypropoxyphenyl)methane, polyglycidyl ethers of phenol-formaldehyde linear oligomers, and bis(4-epoxypropyl)cyclohexyl-4-ene-1,2-dicarboxylic acid ester, etc.

[0032] The molecular weight difference between epoxy resin B and epoxy resin A is preferably ≥5000 g / mol. A large molecular weight difference allows epoxy resin A molecules to enter the spaces between epoxy resin B molecules, inserting into the mesocrystalline interlayer spacing of epoxy resin B, separating adjacent rigid rod-shaped molecules, effectively increasing the free volume of the molecules, and improving the thermal conductivity.

[0033] The molecular weight of epoxy resin A is preferably ≤1200 g / mol. A lower molecular weight allows epoxy resin A to combine with epoxy resin B, increasing the orderliness of epoxy resin B and thus further improving the thermal conductivity of the subsequently manufactured product without affecting its breakdown strength. The lower limit of the molecular weight of epoxy resin A is not specified here.

[0034] The epoxy value of the epoxy resin A is preferably in the range of 0.20 mol / 100g to 0.55 mol / 100g, so that the resin composition has suitable reactivity, moderate resin activity, and moderate degree of crosslinking, thereby improving the thermal conductivity and breakdown strength of the subsequently manufactured product.

[0035] The crosslinking density of the epoxy resin B is preferably 60 mol / L-80 mol / L. By limiting the crosslinking density of the modified liquid crystal epoxy resin to 60 mol / L-80 mol / L, the length of the grafted chain segments on the liquid crystal epoxy resin is moderate, and the modified liquid crystal epoxy resin is less likely to generate electric field concentration in the product, resulting in high breakdown strength of the subsequent product.

[0036] In the epoxy resin B, the molecular weight of the liquid crystal epoxy resin is preferably 2000 g / mol-4000 g / mol. This results in high orientation of the main chain of the liquid crystal epoxy resin and makes it easier to perform subsequent modification operations, thereby simultaneously improving the thermal conductivity and breakdown strength of the subsequent products.

[0037] In the epoxy resin B, the epoxy value of the liquid crystal epoxy resin is preferably 0.20 mol / 100g-0.55 mol / 100g, resulting in a high Tg range for the resin composition. This gives the resin composition suitable reactivity, moderate resin activity, and a moderate degree of crosslinking, thereby simultaneously improving the thermal conductivity and breakdown strength of the subsequent product.

[0038] In this invention, the liquid crystal epoxy resin includes, but is not limited to, one of side-chain biphenyl liquid crystal epoxy resin, side-chain biphenyl liquid crystal epoxy resin, and aromatic ester liquid crystal epoxy resin, or other liquid crystal epoxy resins that meet the specified requirements, or a combination of multiple liquid crystal epoxy resins. For example, the liquid crystal epoxy resin includes, but is not limited to, diacetylene-biphenyl copolymer liquid crystal epoxy resin, 3,3′,5,5′-tetramethylbiphenyl diglycidyl ether, and LCER, etc.

[0039] In some embodiments, the amount of epoxy resin B is 100-235 parts by weight, for example, 100 parts by weight, 130 parts by weight, 160 parts by weight, 190 parts by weight, 220 parts by weight, or 235 parts by weight, based on 100 parts by weight of epoxy resin A.

[0040] In this invention, the epoxy resin B is preferably a liquid crystal epoxy resin modified with a low-polarity compound. On one hand, this introduces low-polarity segments into the liquid crystal epoxy resin, reducing its overall polarity, improving its insulation, and increasing the breakdown strength of subsequent products. On the other hand, it makes the liquid crystal epoxy resin more structurally symmetrical, increasing its orderliness, resulting in a more regular mesocrystalline structure, improved phonon transport efficiency, and increased thermal conductivity of subsequent products.

[0041] The molecular weight of the low-polarity compound is preferably 1000 g / mol to 2000 g / mol. This ensures that the length of the low-polarity chain segments on the modified liquid crystal epoxy resin is moderate, thereby simultaneously improving the thermal conductivity and breakdown strength of the subsequent products.

[0042] The surface polarity of the low-polarity compound is preferably ≤3.0, so that the modified liquid crystal epoxy resin has moderate overall polarity and high insulation, thereby improving the breakdown strength of subsequent products.

[0043] The low-polarity compound is preferably selected from one or more combinations of polyol compounds, polyamine compounds, siloxane compounds, and fluoropolymers. More specifically, the low-polarity compound is a diol compound. Specifically, the diol is preferably selected from one or more combinations of aliphatic straight-chain diols, alicyclic diols, polyether diols, and polyolefin diols. For example, the diol includes, but is not limited to, poly(1,4-butanediol) and poly(4-methyl-2,4-pentanediol).

[0044] The filler is used to fill the circuit board and improve the thermal conductivity. Furthermore, due to the characteristic of epoxy resin B to form a mesocrystalline structure, it induces the filler to disperse and oriented along the mesocrystalline direction. At the same time, during the molding stage, the resin composition has a longer low viscosity stage, which is conducive to the uniform suspension of high-density filler, reduces sedimentation and agglomeration, and allows the thermal conductivity of the filler to be fully exerted, thereby improving the thermal conductivity of the subsequent product.

[0045] In this invention, the filler is selected from one or more combinations of alumina, aluminum nitride, boron nitride, silicon nitride, silicon dioxide, zinc oxide, magnesium oxide and diamond powder. The required filler only needs to meet the requirement that the thermal conductivity is ≥12W / m·K. The particle size range and distribution index of the filler are not limited here.

[0046] In some embodiments, the amount of filler is 1000-2670 parts by weight, based on 100 parts by weight of epoxy resin A, for example, 1000 parts by weight, 1300 parts by weight, 1600 parts by weight, 1900 parts by weight, 2200 parts by weight, 2500 parts by weight, or 2670 parts by weight.

[0047] The resin composition further includes additives, which include at least one of a coupling agent and a curing agent. The coupling agent improves the interfacial bonding of the resin composition, and the type of coupling agent is not limited here. In some embodiments, based on 100 parts by weight of epoxy resin A, the amount of coupling agent is 10 to 35 parts by weight, for example, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, etc.

[0048] In this invention, the type of curing agent is not limited. In some embodiments, based on 100 parts by weight of epoxy resin A, the amount of curing agent is 10-35 parts by weight, for example, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, etc.

[0049] In this invention, the resin composition further includes a solvent.

[0050] This application also provides an article made using the resin composition described above, the article comprising an insulating film, a circuit board, and a printed circuit board.

[0051] This application does not limit the specific preparation method of the insulating film prepared by the resin composition. The structure of the insulating film is a support film and an insulating film in sequence. The resin composition is distributed on the support film by coating or impregnation by means of coating, casting, extrusion or other methods. After drying, the insulating film is formed. The commonly used support film is PET film.

[0052] This application also provides a circuit board made using the aforementioned insulating film. The circuit board can be a copper-clad laminate or other metal substrates. Specifically, the circuit board includes an insulating layer and a conductive layer disposed on at least one surface of the insulating layer. The insulating layer is formed by pressing one or more laminated insulating films as described above after removing the support film. The conductive layer can be copper foil, aluminum foil, nickel foil, silver foil, or their alloy foil, etc. This application does not limit the type of material, but copper foil is preferred.

[0053] Specifically, the printed circuit board is made using the circuit board as described above.

[0054] Specifically, the printed circuit board is mainly made of the circuit substrate through processes such as drilling, hole filling, micro-etching, pre-dip, activation, acceleration, chemical copper plating, and copper thickening.

[0055] The effects of the technical solution of this application will be further illustrated below through several specific application examples.

[0056] Example 1:

[0057] An epoxy resin composition comprising, by weight, the following components:

[0058] Epoxy resin A (specifically, bisphenol A type epoxy resin E-51, molecular weight: 844 g / mol, epoxy value: 0.4 mol / 100 g): 100 parts by weight;

[0059] Epoxy resin B (specifically, a biphenyl main chain liquid crystal epoxy resin modified with polyether glycol, clearing point enthalpy change: 4J / g, crosslinking density: 71mol / L): 150 parts by weight;

[0060] Filler (specifically alumina, 35 W / m·K, AM-21): 1300 parts by weight;

[0061] Coupling agent (specifically silane coupling agent KH560): 10 parts by weight;

[0062] Curing agent (specifically 4,4'-diaminodiphenyl sulfone): 5 parts by weight.

[0063] In the polyether glycol-modified biphenyl-based liquid crystal epoxy resin, the biphenyl-based liquid crystal epoxy resin (NC-3000H) has a molecular weight of 2984 g / mol and an epoxy value of 0.35 mol / 100g, while the polyether glycol (PPG-1000) has a molecular weight of 1500 g / mol and a surface polarity of 1. The molecular weight difference between epoxy resin B and epoxy resin A is 6471 g / mol.

[0064] The preparation method of the above epoxy resin composition is as follows:

[0065] 100 parts by weight of bisphenol A epoxy resin and 150 parts by weight of epoxy resin B were mixed in proportion and dissolved completely with an appropriate amount of butanone solvent. The mixture was stirred at 500 r / min for 1 h. 5 parts by weight of curing agent and 10 parts by weight of coupling agent were added to the epoxy resin mixture and stirred at 500 r / min for 30 min. During the stirring process, 1300 parts by weight of filler were added and the speed was adjusted to 2000 r / min. The mixture was then dispersed at high speed for 40 min to obtain the epoxy resin composition.

[0066] The above epoxy resin composition was degassed and adjusted to a viscosity (4# Zein cup) of 30s-35s. It was then applied to the surface of a PET film using a flatbed coating machine and baked at 110°C for 3 minutes to form an insulating film.

[0067] The epoxy resin B can be a commercially available epoxy resin B that meets the requirements, or it can be prepared by the following methods:

[0068] 150 parts by weight of the above biphenyl main-chain liquid crystal epoxy resin were dissolved in methyl ethyl ketone, and 20 parts by weight of the above polyether diol were added. The mixture was stirred and refluxed at 300 r / min for 1 h while maintaining a water bath temperature of 90 °C. After removing the water bath, stirring was continued to obtain the above epoxy resin B solution. The enthalpy change at the clearing point and the crosslinking density of the epoxy resin B solution could be detected by DSC (differential scanning calorimetry) and equilibrium swelling method.

[0069] It should be noted that the preparation methods of different types of epoxy resin B in the following other embodiments are similar to those of epoxy resin B in Example 1. They can be achieved by simply adjusting the type, proportion and polymerization temperature of the raw materials. The enthalpy change at the clearing point and the crosslinking density of the epoxy resin B solution can be determined by DSC (differential scanning calorimetry) and equilibrium swelling method test results. The details will not be repeated here.

[0070] Example 2:

[0071] The difference between this embodiment and Embodiment 1 is that:

[0072] In this embodiment, the filler in the epoxy resin composition is magnesium oxide (ZH-V3) with a thermal conductivity of 12 W / m·K. Epoxy resin B is a biphenyl-based liquid crystal epoxy resin modified with polyether glycol. The polyether glycol is the same as in Example 1. The molecular weight of the biphenyl-based liquid crystal epoxy resin (DPDA-ER) is 3129 g / mol, and the epoxy value is 0.35 mol / 100 g. The final epoxy resin B has a clearing enthalpy of 2 J / g and a crosslinking density of 62 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6026 g / mol.

[0073] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0074] Example 3:

[0075] The difference between this embodiment and Embodiment 1 is that:

[0076] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a polyether glycol-modified aromatic ester-type liquid crystal epoxy resin. The polyether glycol is the same as in Example 1. The aromatic ester-type liquid crystal epoxy (DGE-TMBPBHB) has a molecular weight of 2580 g / mol and an epoxy value of 0.35 mol / 100 g. The final epoxy resin B has a clearing enthalpy of 5 J / g and a crosslinking density of 80 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6805 g / mol.

[0077] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0078] Example 4:

[0079] The difference between this embodiment and Embodiment 1 is that:

[0080] In this embodiment, epoxy resin A is a phenolic epoxy resin (NPPN-631) with a molecular weight of 1929 g / mol and an epoxy value of 0.2 mol / 100 g. The molecular weight difference between epoxy resin B and epoxy resin A is 5386 g / mol.

[0081] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0082] Example 5:

[0083] The difference between this embodiment and Embodiment 1 is that:

[0084] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a polyether glycol-modified side-chain biphenyl liquid crystal epoxy resin. The polyether glycol is the same as in Example 1. The side-chain biphenyl liquid crystal epoxy resin (YX-4000H) has a molecular weight of 5033 g / mol and an epoxy value of 0.20 mol / 100 g. The final epoxy resin B has a clearing enthalpy of 4 J / g and a crosslinking density of 65 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 8754 g / mol.

[0085] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0086] Example 6:

[0087] The difference between this embodiment and Embodiment 1 is that:

[0088] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a biphenyl-based liquid crystal epoxy resin modified with an organosilicon diamine. The organosilicon diamine (Tech-2420) has a molecular weight of 1824 g / mol and a surface polarity of 2.5. The biphenyl-based liquid crystal epoxy resin is the same as in Example 1. The final epoxy resin B has a clearing enthalpy of 4 J / g and a crosslinking density of 72 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6618 g / mol.

[0089] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0090] Example 7:

[0091] The difference between this embodiment and Embodiment 1 is that:

[0092] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a biphenyl-based liquid crystal epoxy resin modified with polyether glycol. The polyether glycol (P2010) has a molecular weight of 1634 g / mol and a surface polarity of 4. The biphenyl-based liquid crystal epoxy resin is the same as in Example 1. The final epoxy resin B has a clearing enthalpy of 5 J / g and a crosslinking density of 73 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6503 g / mol.

[0093] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0094] Example 8:

[0095] The difference between this embodiment and Embodiment 1 is that:

[0096] In the epoxy resin composition of this embodiment, the epoxy resin A is 100 parts by weight, the epoxy resin B is 100 parts by weight, and the curing agent is 3 parts by weight.

[0097] The other components in the epoxy resin composition and the other components in the weight proportions are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0098] Example 9:

[0099] The difference between this embodiment and Embodiment 1 is that:

[0100] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a biphenyl-based liquid crystal epoxy resin modified with polyether glycol. The polyether glycol and biphenyl-based liquid crystal epoxy resin are the same as in Example 1. However, epoxy resin B is prepared using 10 parts by weight of polyether glycol and 150 parts by weight of biphenyl-based liquid crystal epoxy resin. The final epoxy resin B has a clearing enthalpy of 5 J / g and a crosslinking density of 65 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 4215 g / mol.

[0101] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0102] Example 10:

[0103] The difference between this embodiment and Embodiment 1 is that:

[0104] In this embodiment, the epoxy resin composition contains epoxy resin B, which is a polyether glycol-modified aromatic ester-type liquid crystal epoxy resin. The polyether glycol is the same as in Example 1. The aromatic ester-type liquid crystal epoxy resin (KBF-3000) has a molecular weight of 3087 g / mol and an epoxy value of 0.36 mol / 100 g. The final epoxy resin B has a clearing enthalpy change of 4 J / g and a crosslinking density of 85 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6489 g / mol.

[0105] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0106] Comparative Example 1:

[0107] The difference between this comparative example and Example 1 is as follows:

[0108] In this comparative example, epoxy resin composition does not contain epoxy resin B, and epoxy resin A is present in 250 parts by weight.

[0109] The other components in the epoxy resin composition and the other components in the weight proportions are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0110] Comparative Example 2:

[0111] The difference between this comparative example and Example 1 is as follows:

[0112] In this comparative example, the epoxy resin composition, epoxy resin B is a biphenyl-based liquid crystal epoxy resin modified with polyether glycol. The polyether glycol is the same as in Example 1. The biphenyl-based liquid crystal epoxy resin (KD-BP-300) has a molecular weight of 3122 g / mol and an epoxy value of 0.32 mol / 100 g. The final epoxy resin B has a clearing enthalpy of 8 J / g and a crosslinking density of 70 mol / L. The molecular weight difference between epoxy resin B and epoxy resin A is 6525 g / mol.

[0113] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0114] Comparative Example 3:

[0115] The difference between this comparative example and Example 1 is as follows:

[0116] In the epoxy resin composition of this comparative example, epoxy resin B is an unmodified biphenyl main chain liquid crystal epoxy resin, wherein the biphenyl main chain liquid crystal epoxy resin is the same as that in Example 1.

[0117] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0118] Comparative Example 4:

[0119] The difference between this comparative example and Example 1 is as follows:

[0120] In the epoxy resin composition of this comparative example, the filler is silica (10W / m·K, EP-IN-SiO2-083).

[0121] The other components in the epoxy resin composition and the weight parts of each component are the same as in Example 1, and the preparation method of the insulating film is the same as in Example 1.

[0122] The performance of the insulating film samples prepared in Examples 1-10 and Comparative Examples 1-4 was tested using the following methods:

[0123] Thermal conductivity: After removing the PET film on the surface of the insulating film, multiple layers are stacked and vacuum-pressed to obtain the insulating sheet. The thermal conductivity of the insulating layer is tested according to ASTM D5470-17 standard.

[0124] Breakdown strength: After removing the PET film from an insulating film, it is sequentially covered with copper foil on the surface of an aluminum plate and pressed at 190°C for 2 hours to obtain a metal substrate. The metal substrate is etched and cut into a 10*10cm square piece, with a 5cm diameter circular copper area in the middle. The breakdown strength is tested according to the IPC-TM-6502.5.6.2 standard.

[0125] The performance test results are shown in the table below:

[0126] Table 1: Performance test results of insulating film samples prepared in Examples 1-10 and Comparative Examples 1-4

[0127] Group Thermal conductivity (W / (m·K)) Breakdown strength (KV / mm) Example 1 2.5 65 Example 2 2.3 65 Example 3 2.6 58 Example 4 2.3 60 Example 5 2.2 58 Example 6 2.5 55 Example 7 2.5 52 Example 8 2.7 52 Example 9 2.2 60 Example 10 2.5 53 Comparative Example 1 1.8 48 Comparative Example 2 2.8 36 Comparative Example 3 2.1 44 Comparative Example 4 1.6 52

[0128] As shown in Table 1 above, the insulating films prepared in the various embodiments of this application possess both high thermal conductivity and high breakdown strength. As can be seen from Example 1 and Comparative Examples 1-4, by introducing a modified liquid crystal epoxy resin into ordinary epoxy resin and limiting the thermal conductivity of the filler to ≥12 W / m·K, the insulating film prepared from this resin composition can have a high basic thermal conductivity. Furthermore, by limiting the clearing point enthalpy of the modified liquid crystal epoxy resin to 2 J / g-5 J / g, the insulating film prepared from this resin composition can possess both high thermal conductivity and high breakdown strength. As can be seen from Examples 1-10, when the molecular weight or epoxy value of epoxy resin A (i.e., ordinary epoxy resin), or the crosslinking density of epoxy resin B (i.e., modified liquid crystal epoxy resin), or the molecular weight or epoxy value of the liquid crystal epoxy resin in epoxy resin B, or the molecular weight or surface polarity or type of the low polar compound used as a modifier in epoxy resin B, or the difference in molecular weight between epoxy resin B and epoxy resin A, is not within the preferred range of this scheme, although there are differences in the thermal conductivity and breakdown strength of the insulating film, it can still have high thermal conductivity and high breakdown strength.

[0129] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions, alterations, deletions of some features, additions of features, or recombinations of features to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the innovative principles of the present invention shall still fall within the scope of the technical solutions of the present invention.

Claims

1. An epoxy resin composition, characterized by comprising: The composition comprises epoxy resin A, epoxy resin B and filler, wherein the epoxy resin A is a common epoxy resin; the epoxy resin B is a modified liquid crystal epoxy resin, the epoxy resin B has an enthalpy change of 2J / g-5J / g at clear point; the thermal conductivity of the filler is greater than or equal to 12W / m·K.

2. The epoxy resin composition according to claim 1, characterized in that The difference between the molecular weight of the epoxy resin B and the epoxy resin A is greater than or equal to 5000g / mol.

3. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin A at least meets one of the following conditions: (1) the molecular weight of the epoxy resin A is less than or equal to 1200g / mol; (2) the epoxy value of the epoxy resin A ranges from 0.20mol / 100g to 0.55mol / 100g.

4. The epoxy resin composition according to claim 1, characterized by The crosslinking density of the epoxy resin B is 60mol / L-80mol / L.

5. The epoxy resin composition according to claim 1, wherein The liquid crystal epoxy resin in the epoxy resin B at least meets one of the following conditions: (1) the molecular weight of the liquid crystal epoxy resin is 2000g / mol-4000g / mol; (2) the epoxy value of the liquid crystal epoxy resin is 0.20mol / 100g-0.55mol / 100g.

6. The epoxy resin composition according to claim 1, characterized in that, The epoxy resin B is a liquid crystal epoxy resin modified by a low-polarity compound, and the low-polarity compound at least meets one of the following conditions: (1) the molecular weight of the low-polarity compound is 1000g / mol-2000g / mol; (2) the surface polarity of the low-polarity compound is less than or equal to 3.

0.

7. The epoxy resin composition according to claim 6, characterized in that The low-polarity compound is selected from one or more combinations of polyol compound, polyamine compound, siloxane compound and fluororesin.

8. The epoxy resin composition according to claim 6, characterized in that The low-polarity compound is a dihydric alcohol compound.

9. The epoxy resin composition according to claim 1, wherein The amount of the epoxy resin B is 100-235 parts by weight based on 100 parts by weight of the epoxy resin A, and the amount of the filler is 1000-2670 parts by weight based on 100 parts by weight of the epoxy resin A.

10. An article of manufacture using the epoxy resin composition according to any one of claims 1 to 9, characterized by, The product includes insulating adhesive film, circuit substrate and printed circuit board.