Plug-hole resin composition for circuit board and preparation method thereof, and plug-hole circuit board

Abstract

The present invention discloses a plugging resin composition for a circuit board, a preparation method thereof, and a plugging circuit board. The plugging resin composition for a circuit board comprises a resin, a curing agent, a curing accelerator, an inorganic hollow filler, and an inorganic porous filler. The plugging resin composition for a circuit board of the present invention comprises a resin, a curing agent, a curing accelerator, an inorganic hollow filler, and an inorganic porous filler. The inorganic hollow filler has a low dielectric constant, and the inorganic hollow filler and the inorganic porous filler can also improve the heat resistance of the plugging resin composition. Combined with the data of the test example part, the plugging resin composition for a circuit board of the present invention has better heat resistance and a significantly reduced dielectric constant compared with the comparative example.

Description

Technical Field

[0001] The invention relates to the field of circuit board processing, in particular to a plugging resin composition for circuit boards and a preparation method thereof, and a plugging circuit board. Background Art

[0002] As electronic products develop towards lightweight, miniaturization and high speed, higher requirements are placed on printed circuit boards. In recent years, resin plugging technology that uses light- and heat-curable plugging resin compositions to fill circuit board through holes has been widely used in the production of circuit boards.

[0003] The resin plugging process can reduce the design size of the circuit board and improve the wiring capacity of the PCB. The resin plugging process includes drilling, electroplating, baking, and grinding. The specific process is to plate the hole through after drilling on the PCB, then plug the resin into the hole and bake it, then grind the resin and smooth it, and finally plate a layer of copper on the resin. The effect is that the hole can be conductive and the surface is flat, and normal wiring can be carried out.

[0004] With the continuous development of technology, especially the emergence of high-frequency and high-speed circuit boards, the industry's requirements for plugging resin compositions are constantly increasing, especially for the heat resistance and low dielectric properties of the cured plugging resin compositions. Summary of the invention

[0005] Based on this, it is necessary to provide a plugging resin composition for circuit boards that can solve the above problems.

[0006] In addition, it is also necessary to provide a method for preparing the above-mentioned plugging resin composition for a circuit board and a plugging circuit board comprising the above-mentioned plugging resin composition.

[0007] A plugging resin composition for a circuit board comprises a resin, a curing agent, a curing accelerator, an inorganic hollow filler and an inorganic porous filler.

[0008] In one embodiment, the resin comprises 20 to 50 parts by weight, 0.5 to 5 parts by weight of the curing agent, 0.5 to 5 parts by weight of the curing accelerator, 10 to 20 parts by weight of the inorganic hollow filler, and 20 to 50 parts by weight of the inorganic porous filler.

[0009] In one embodiment, the inorganic hollow filler has a true density of 0.3 g / cm 3 ~0.7g / cm 3 Hollow glass microspheres.

[0010] In one embodiment, the inorganic porous filler is a mixture of nano-silicon dioxide and fumed silicon dioxide powder in a mass ratio of 1-2:1-2.

[0011] In one embodiment, the 20 to 50 parts of resin are 15 to 40 parts of epoxy resin and 5 to 10 parts of phenolic resin.

[0012] In one embodiment, the epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester epoxy resin and glycidyl amine epoxy resin;

[0013] The phenolic resin is selected from at least one of aminotriazine phenolic resin, allylated novolac resin, phenol phenolic resin, cresol phenolic resin and trisphenol methane phenolic resin.

[0014] In one embodiment, the curing agent is selected from at least one of aliphatic polyamines, diacetone acrylamide, alicyclic polyamines, triethanolamine, m-phenylenediamine, diaminodiphenyl sulfone, diaminodiphenylmethane, m-phenylenediamine, polyetheramine, amidoamine, polyurethane, boron trifluoride, cyanate esters and polythiol;

[0015] The curing accelerator is selected from at least one of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-ethyl-4-phenylimidazole and 1-cyanoethyl-2-ethyl-4-phenylimidazole.

[0016] A method for preparing the above-mentioned plugging resin composition for circuit boards comprises the following steps:

[0017] Separating the resin, the curing agent and the curing accelerator into a first component and a second component, wherein the mass ratio of the first component to the second component is 1 to 3:10;

[0018] The first component and the inorganic hollow filler are uniformly mixed and then cured to form a cured product, and then the cured product is crushed to obtain a modified inorganic hollow filler;

[0019] The second component, the modified inorganic hollow filler and the inorganic porous filler are mixed evenly and then ground, then mixed evenly again, and vacuum degassed to obtain the desired plugging resin composition for circuit boards.

[0020] In one embodiment, the operation of uniformly mixing the first component and the inorganic hollow filler and then curing to form a cured product is as follows: the inorganic hollow filler is modified with a silane coupling agent and then mixed evenly with the first component, followed by heat treatment at 100°C to 130°C for 0.5h to 2h, and then heat treatment at 160°C to 180°C for 0.5h to 2h to obtain a plate-shaped cured product with a thickness of 0.5mm to 2mm.

[0021] A plugging circuit board comprises the plugging resin composition.

[0022] The plugging resin composition for circuit boards of the present invention comprises resin, curing agent, curing accelerator, inorganic hollow filler and inorganic porous filler. The inorganic hollow filler has a low dielectric constant. The inorganic hollow filler and inorganic porous filler can also improve the heat resistance of the plugging resin composition.

[0023] Combined with the data of the test examples, the plugging resin composition for circuit boards of the present invention has better heat resistance and a significantly lower dielectric constant than the comparative example.

[0024] Preferably, in the present invention, the inorganic porous filler is a mixture of nano-silicon dioxide and fumed silica powder in a mass ratio of 1-2:1-2, and the fumed silica powder can also act as a leveling agent in the plugging resin composition.

[0025] Preferably, in the present invention, the resin is an epoxy resin and a phenolic resin, and the phenolic resin can react with the epoxy resin to reduce the dielectric constant of the plugging resin composition.

[0026] In addition, considering the low density of inorganic hollow fillers, for example, the actual density of hollow glass microspheres (0.1 g / cm 3 ~0.7g / cm 3 ) is significantly lower than the density of epoxy resin (about 1.2 g / mL). As a result, when the plugging resin composition for circuit boards of the present invention is cured, the hollow glass microspheres are easily floated up, thereby aggregating in large quantities on the surface of the circuit board, which is not conducive to the overall structural stability of the plugging holes, affects the heat resistance of the plugging resin composition after curing, and is not conducive to the subsequent processing of the circuit board.

[0027] In the present invention, the inorganic hollow filler is mixed with a small amount of resin, a curing agent and a curing accelerator, and then solidified, and then crushed to obtain a modified inorganic hollow filler, so that the density of the modified inorganic hollow filler is greatly improved, and the above-mentioned problem is well solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] in:

[0030] Figure 1 The present invention is a flow chart of a method for preparing a via plugging resin composition for a circuit board according to one embodiment. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The invention discloses a plugging resin composition for a circuit board according to an embodiment of the present invention, comprising a resin, a curing agent, a curing accelerator, an inorganic hollow filler and an inorganic porous filler.

[0033] The plugging resin composition for circuit boards of the present invention comprises resin, curing agent, curing accelerator, inorganic hollow filler and inorganic porous filler. The inorganic hollow filler has a low dielectric constant. The inorganic hollow filler and inorganic porous filler can also improve the heat resistance of the plugging resin composition.

[0034] Combined with the data of the test examples, the plugging resin composition for circuit boards of the present invention has better heat resistance and a significantly lower dielectric constant than the comparative example.

[0035] Preferably, in parts by mass, the plugging resin composition for circuit boards of this embodiment includes 20 to 50 parts of resin, 0.5 to 5 parts of curing agent, 0.5 to 5 parts of curing accelerator, 10 to 20 parts of inorganic hollow filler and 20 to 50 parts of inorganic porous filler.

[0036] Preferably, in this embodiment, the inorganic hollow filler has a true density of 0.3 g / cm 3 ~0.7g / cm 3 Hollow glass microspheres.

[0037] Specifically, in this embodiment, the particle size of the hollow glass microspheres may be 5 micrometers to 16 micrometers.

[0038] It should be pointed out that the densities involved in the present invention are all true densities, not bulk densities.

[0039] Hollow glass microspheres are cheap and can significantly reduce the dielectric constant of the plugging resin composition.

[0040] Preferably, in this embodiment, the inorganic porous filler is a mixture of nano-silicon dioxide and fumed silicon dioxide powder in a mass ratio of 1-2:1-2.

[0041] The hollow glass microspheres, nano-silicon dioxide and fumed silica powder can be connected to each other to form a network structure, thereby improving the integrity of the hole plugging resin composition after curing.

[0042] In addition, the fumed silica powder can also act as a leveling agent in the plugging resin composition.

[0043] Specifically, in this embodiment, the particle size of nano-silicon dioxide can be 5 micrometers to 20 micrometers, and the particle size of fumed silicon dioxide powder can be 100 nanometers to 20 micrometers.

[0044] Preferably, in this embodiment, the 20 to 50 parts of resin are 15 to 40 parts of epoxy resin and 5 to 10 parts of phenolic resin.

[0045] The phenolic resin can react with the epoxy resin to reduce the dielectric constant of the plugging resin composition.

[0046] Preferably, in this embodiment, the epoxy resin is selected from at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, aliphatic glycidyl ether epoxy resin, glycidyl ester epoxy resin and glycidyl amine epoxy resin.

[0047] Preferably, in this embodiment, the phenolic resin is selected from at least one of aminotriazine phenolic resin, allylated novolac resin, phenol phenolic resin, cresol phenolic resin and trisphenol methane phenolic resin.

[0048] Preferably, in this embodiment, the curing agent is selected from at least one of aliphatic polyamines, diacetone acrylamide, alicyclic polyamines, triethanolamine, m-phenylenediamine, diaminodiphenyl sulfone, diaminodiphenylmethane, m-phenylenediamine, polyetheramine, amide amine, polyurethane, boron trifluoride, cyanate and polythiol.

[0049] Preferably, in this embodiment, the curing accelerator is selected from at least one of imidazole, 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-ethyl-4-phenylimidazole, and 1-cyanoethyl-2-ethyl-4-phenylimidazole.

[0050] Combination Figure 1 The present invention also discloses a method for preparing the above-mentioned plugging resin composition for circuit boards according to an embodiment of the present invention, comprising the following steps:

[0051] S10, dividing the resin, the curing agent and the curing accelerator into a first component and a second component.

[0052] Preferably, the mass ratio of the first component to the second component is 1 to 3:10.

[0053] S20, uniformly mixing the first component obtained in S10 and the inorganic hollow filler, and then curing to form a cured product, and then crushing the cured product to obtain a modified inorganic hollow filler.

[0054] Considering the low density of inorganic hollow fillers, for example, the actual density of hollow glass microspheres (0.1 g / cm 3 ~0.7g / cm 3 ) is significantly lower than the density of epoxy resin (about 1.2 g / mL). As a result, when the plugging resin composition for circuit boards of the present invention is cured, the hollow glass microspheres are easily floated up, thereby aggregating in large quantities on the surface of the circuit board, which is not conducive to the overall structural stability of the plugging holes, affects the heat resistance of the plugging resin composition after curing, and is not conducive to the subsequent processing of the circuit board.

[0055] In the present invention, the inorganic hollow filler is mixed with a small amount of resin, a curing agent and a curing accelerator, and then solidified, and then crushed to obtain a modified inorganic hollow filler, so that the density of the modified inorganic hollow filler is greatly improved, and the above-mentioned problem is well solved.

[0056] Preferably, in S20, the operation of uniformly mixing the first component and the inorganic hollow filler and then curing to form a cured product is as follows: the inorganic hollow filler is modified with a silane coupling agent and then uniformly mixed with the first component, followed by heat treatment at 100°C to 130°C for 0.5h to 2h, and then heat treatment at 160°C to 180°C for 0.5h to 2h to obtain a plate-shaped cured product with a thickness of 0.5mm to 2mm.

[0057] In order to ensure that the thickness of the plate-like cured product is 0.5 mm to 2 mm, the above-mentioned curing operation can be carried out at 30 kg / cm 2 ~100kg / cm 2 under pressure.

[0058] The plate-like solidified product with a thickness of 0.5 mm to 2 mm is convenient for subsequent crushing.

[0059] The particle size of the modified inorganic hollow filler obtained after crushing can be 6 microns to 20 microns.

[0060] In this embodiment, the silane coupling agent is KH-550.

[0061] The operation of modifying the inorganic hollow filler with a silane coupling agent is as follows: immersing the inorganic hollow filler in a 0.5wt% to 2wt% KH-550 aqueous solution, stirring and dispersing for 2h to 5h, and then drying.

[0062] S30, the second component obtained in S10, the modified inorganic hollow filler and the inorganic porous filler obtained in S20 are mixed evenly and then ground, then mixed evenly again, and vacuum degassing is performed to obtain the desired plugging resin composition for circuit boards.

[0063] Preferably, the second component obtained in S10, the modified inorganic hollow filler and the inorganic porous filler obtained in S20 are mixed and then ground, and then mixed again. The specific operation is: the second component obtained in S10 is stirred at a speed of 300rpm to 600rpm for 15min to 45min, and then continued to stir at a speed of 100rpm to 200rpm for 6h to 24h, and then the modified inorganic hollow filler and the inorganic porous filler obtained in S20 are added and continued to stir at a speed of 300rpm to 600rpm for 15min to 45min, and then the mixture is ground 2 to 10 times using a three-roll grinder, and then the ground mixture is stirred again at a speed of 300rpm to 600rpm for 15min to 45min.

[0064] The present invention also discloses a plugging circuit board including the plugging resin composition according to an embodiment of the present invention.

[0065] The following is a specific embodiment. Among them, the bisphenol A epoxy resin is a low-viscosity standard electronic grade resin NPEL127E purchased from Nan Ya Plastics Industry Co., Ltd., the allylated phenolic varnish resin is MEH8000 purchased from Meiwa Plastics Industry Co., Ltd., and the hollow glass microspheres are purchased from Guangdong Zhaotong Glass Plastic Technology Co., Ltd. (particle size is 10 microns, true density is 0.42 g / cm 3 ), fumed silica powder was purchased from Wuzhen Technology Group Hebei Co., Ltd. (particle size of 10 μm, porosity of 90%), and nano-silicon dioxide was purchased from Wacker Chemie Co., Ltd., Germany (HDK H2000, mesh number of 1250 mesh).

[0066] Example 1

[0067] 30 g of bisphenol A epoxy resin, 8 g of allylated phenolic varnish resin, 1 g of triethanolamine, 0.5 g of 2-ethyl-4-methylimidazole, 15 g of hollow glass microspheres, 20 g of nano-silicon dioxide and 10 g of fumed silica powder were weighed respectively.

[0068] Bisphenol A epoxy resin, allylated novolac resin, triethanolamine and 2-ethyl-4-methylimidazole are divided into a first component and a second component, and the mass ratio of the first component to the second component is 2:10.

[0069] Soak the hollow glass microspheres in a 1wt% KH-550 aqueous solution, stir and disperse for 3h and then dry. Then mix the dried hollow glass microspheres with the first component, stir at 300rpm to 600rpm for 15min to 45min, and finally pour into a mold and maintain a pressure of 45kg / cm 2 The product was heat treated at 120°C for 0.5 h and then at 160°C for 1 h to obtain a plate-shaped cured product with a thickness of 1 mm.

[0070] The plate-like solidified product is crushed and screened to obtain modified hollow glass microspheres with a particle size of 10 microns to 20 microns.

[0071] The second component was stirred at 450 rpm for 30 min, and then continued to be stirred at 120 rpm for 12 h, and then the modified hollow glass microspheres, nano-silicon dioxide and fumed silica powder were added and continued to be stirred at 450 rpm for 20 min, and then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450 rpm for 20 min, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

[0072] Example 2

[0073] 15 g of bisphenol A epoxy resin, 5 g of allylated novolac resin, 0.5 g of triethanolamine, 0.5 g of 2-ethyl-4-methylimidazole, 10 g of hollow glass microspheres, 10 g of nano-silicon dioxide and 10 g of fumed silica powder were weighed respectively.

[0074] Bisphenol A epoxy resin, allylated novolac resin, triethanolamine and 2-ethyl-4-methylimidazole are divided into a first component and a second component, and the mass ratio of the first component to the second component is 2:10.

[0075] Soak the hollow glass microspheres in a 1wt% KH-550 aqueous solution, stir and disperse for 3h and then dry. Then mix the dried hollow glass microspheres with the first component, stir at 300rpm to 600rpm for 15min to 45min, and finally pour into a mold and maintain a pressure of 45kg / cm 2 The product was heat treated at 120°C for 1 h and then at 160°C for 1 h to obtain a plate-shaped cured product with a thickness of 1 mm.

[0076] The plate-like solidified product is crushed and screened to obtain modified hollow glass microspheres with a particle size of 10 microns to 20 microns.

[0077] The second component was stirred at 450 rpm for 30 min, and then continued to be stirred at 120 rpm for 12 h, and then the modified hollow glass microspheres, nano-silicon dioxide and fumed silica powder were added and continued to be stirred at 450 rpm for 20 min, and then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450 rpm for 20 min, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

[0078] Example 3

[0079] 40 g of bisphenol A epoxy resin, 10 g of allylated phenolic varnish resin, 5 g of triethanolamine, 1 g of 2-ethyl-4-methylimidazole, 20 g of hollow glass microspheres, 20 g of nano-silicon dioxide and 30 g of fumed silica powder were weighed respectively.

[0080] Bisphenol A epoxy resin, allylated novolac resin, triethanolamine and 2-ethyl-4-methylimidazole are divided into a first component and a second component, and the mass ratio of the first component to the second component is 2:10.

[0081] Soak the hollow glass microspheres in a 1wt% KH-550 aqueous solution, stir and disperse for 3h and then dry. Then mix the dried hollow glass microspheres with the first component, stir at 300rpm to 600rpm for 15min to 45min, and finally pour into a mold and maintain a pressure of 45kg / cm 2 The product was heat treated at 120°C for 0.5 h and then at 160°C for 1.5 h to obtain a plate-shaped cured product with a thickness of 1 mm.

[0082] The plate-like solidified product is crushed and screened to obtain modified hollow glass microspheres with a particle size of 10 microns to 20 microns.

[0083] The second component was stirred at 450 rpm for 30 min, and then continued to be stirred at 120 rpm for 12 h, and then the modified hollow glass microspheres, nano-silicon dioxide and fumed silica powder were added and continued to be stirred at 450 rpm for 20 min, and then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450 rpm for 20 min, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

[0084] Comparative Example 1

[0085] 30 g of bisphenol A epoxy resin, 8 g of allylated novolac resin, 1 g of triethanolamine, 0.5 g of 2-ethyl-4-methylimidazole, 20 g of nano-silicon dioxide and 10 g of fumed silicon dioxide powder were weighed respectively.

[0086] Bisphenol A epoxy resin, allylated phenolic varnish resin, triethanolamine and 2-ethyl-4-methylimidazole were stirred at 450 rpm for 30 minutes, and then continued to stir at 120 rpm for 12 hours, and then nano-silicon dioxide and fumed silica powder were added and continued to stir at 450 rpm for 20 minutes, and then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450 rpm for 20 minutes, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

[0087] Comparative Example 2

[0088] 30 g of bisphenol A epoxy resin, 8 g of allylated phenolic varnish resin, 1 g of triethanolamine, 0.5 g of 2-ethyl-4-methylimidazole, 15 g of hollow glass microspheres, 20 g of nano-silicon dioxide and 10 g of fumed silica powder were weighed respectively.

[0089] The hollow glass microspheres were immersed in a 1wt% KH-550 aqueous solution, stirred and dispersed for 3 hours and then dried. Bisphenol A epoxy resin, allylated phenolic varnish resin, triethanolamine and 2-ethyl-4-methylimidazole were stirred at 450rpm for 30 minutes, then continued to stir at 120rpm for 12 hours, then the dried hollow glass microspheres, nano-silicon dioxide and fumed silica powder were added and continued to stir at 450rpm for 20 minutes, then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450rpm for 20 minutes, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

[0090] Test Case

[0091] 1. Heat resistance test

[0092] The plugging resin compositions for circuit boards prepared by the conventional wire mesh plugging method in Examples 1 to 3 and Comparative Examples 1 to 2 were respectively used to plug holes (hole diameter of 0.5 mm) on a printed circuit board with a thickness of 1.2 mm and then cured to prepare a plugged circuit board. The curing conditions were heat treatment at 120°C for 0.5 h, followed by heat treatment at 160°C for 1.5 h.

[0093] The prepared plugged hole circuit board was placed in an oven at 288°C for 6 hours, then taken out and the state of the plugged hole was observed. The test results are shown in Table 1 below.

[0094] Table 1

[0095]

[0096] It can be seen from Table 1 that in Test Example 2, due to the direct addition of hollow glass microspheres, the hole plugging resin composition after curing exhibits cracking and delamination at high temperatures.

[0097] 2. Dielectric constant test

[0098] The plugging resin compositions for circuit boards prepared in Examples 1 to 3 and Comparative Examples 1 to 2 were respectively added into a mold and cured to prepare samples, which were round pieces with a diameter of 50 mm and a thickness of 2 mm.

[0099] The node constant test was carried out in a wide frequency range of 8 GHz to 16 GHz, the test standard was GB / T5597-1999, the test frequency was 7 GHz to 19 GHz, and the cavity resonance method was used for testing. The test results are shown in Table 2 below.

[0100] Table 2

[0101] 8GHz 10GHz 12GHz 14GHz 16GHz 18GHz Example 1 2.88 2.84 2.78 2.82 2.81 2.86 Example 2 2.95 2.87 2.98 2.92 2.91 2.93 Example 3 2.92 2.85 2.82 2.89 2.81 2.84 Test Example 1 3.45 3.52 3.48 3.5 3.61 3.42 Test Example 2 2.62 2.54 2.58 2.67 2.51 2.6

[0102] It can be seen from Table 2 that the dielectric constants of the samples of the plugging resin compositions for circuit boards prepared in Examples 1 to 3 and Test Example 2 after curing are all less than 3, which is significantly lower than that of Test Example 1.

[0103] This shows that the dielectric constant can be greatly reduced after adding hollow glass microspheres.

[0104] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a plugging resin composition for a circuit board, characterized in that: The steps include: Weigh 30 g of bisphenol A epoxy resin, 8 g of allylated novolac resin, 1 g of triethanolamine, 0.5 g of 2-ethyl-4-methylimidazole, 15 g of hollow glass microspheres, 20 g of nano-silicon dioxide, and 10 g of fumed silica powder respectively; Divide bisphenol A epoxy resin, allylated novolac resin, triethanolamine and 2-ethyl-4-methylimidazole into a first component and a second component, wherein the mass ratio of the first component to the second component is 2:10; Soak the hollow glass microspheres in a 1wt% KH-550 aqueous solution, stir and disperse for 3h and then dry. Then mix the dried hollow glass microspheres with the first component, stir at 300rpm to 600rpm for 15min to 45min, and finally pour into a mold and maintain a pressure of 45kg / cm 2 The product was heat treated at 120°C for 0.5 h and then at 160°C for 1 h to obtain a plate-like solidified product with a thickness of 1 mm. The plate-like solidified product is crushed and screened to obtain modified hollow glass microspheres with a particle size of 10 microns to 20 microns; The second component was stirred at 450 rpm for 30 min, and then continued to be stirred at 120 rpm for 12 h, and then the modified hollow glass microspheres, nano-silicon dioxide and fumed silica powder were added and continued to be stirred at 450 rpm for 20 min, and then the mixture was ground 5 times using a three-roll grinder, and then the ground mixture was stirred again at 450 rpm for 20 min, and the desired plugging resin composition for circuit boards was obtained after vacuum degassing.

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