TWI872825B - Resin composition, prepreg, and printed circuit boardwith modified hollow microspheres - Google Patents

Abstract

A resin composition, prepreg, and printed circuit board with modified hollow microspheres is provided. The resin composition includes 10 to 80 parts by weight of modified hollow microsphere, 5 to 60 parts by weight of polyphenylene ether resin, and 5 to 30 parts by weight of hardener. The modified hollow microsphere is provided by the following steps: (a) mixing hollow spherical silicon dioxide, siloxane coupling agent and ethanol solution evenly and stir for a first predetermined time; (b) adding alkaline solution and continue stirring for a second predetermined time; (c) processing centrifuge and decant the ethanol clarified to remove the powder; and (d) drying the powder under vacuum to obtain the modified hollow microsphere.

Description

Resin composition, prepreg and printed circuit board containing modified hollow microspheres

The present invention relates to a resin composition prepreg sheet and a printed circuit board, and in particular to a resin composition prepreg sheet containing modified hollow microspheres and a printed circuit board.

In order to meet the needs of high-frequency transmission, the dielectric substrate used in electronic components must have characteristics such as low dielectric constant and low dielectric loss. The existing technology adds hollow fillers to the dielectric substrate and uses the characteristics of air with low dielectric constant in the fillers to reduce the dielectric constant and dielectric loss of the dielectric substrate.

Furthermore, hollow borosilicate glass microspheres are widely used in dielectric substrate materials. However, hollow borosilicate glass microspheres contain a variety of metal oxides such as sodium oxide (Na ₂ O), boron oxide (B ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ), which will lead to increased dielectric loss and reduced thermal stability. In addition, the addition of hollow glass can easily cause the dielectric substrate to have brittle mechanical properties.

Therefore, the prior art also uses hollow silica fillers with better heat resistance, mechanical properties, and electrical properties. However, the hollow silica fillers have poor compatibility with the organic phase molecules in the dielectric matrix.

Therefore, how to improve the compatibility of hollow silica fillers through molecular design improvements to overcome the above-mentioned defects has become one of the important issues that the industry wants to solve.

The technical problem to be solved by the present invention is to provide a resin composition containing modified hollow microspheres, a prepreg sheet and a printed circuit board to address the shortcomings of the existing technology, so as to improve the problems of incompatibility and processability after adding the existing hollow microsphere silica directly into the resin composition, and at the same time improve the electrical properties of the dielectric substrate.

In order to solve the above technical problems, one of the technical solutions adopted by the present invention is to provide a resin composition containing modified hollow microspheres, which includes: 10 to 80 parts by weight of modified hollow microspheres; 5 to 60 parts by weight of polyphenylene ether resin; and 5 to 30 parts by weight of hardener, based on the total weight of the resin composition being 100 parts by weight. The modified hollow microspheres are prepared by the following steps: (a) uniformly mixing hollow spherical silica, a siloxane coupling agent and an ethanol solution and stirring for a first predetermined time; (b) adding an alkaline solution and continuously stirring for a second predetermined time; (c) centrifuging and pouring out the ethanol clarified liquid to take out the powder; and (d) drying the powder in a vacuum environment to obtain the modified hollow microspheres.

In one embodiment of the present invention, the resin composition further comprises 0.1 to 5 parts by weight of a catalyst.

In one embodiment of the present invention, the catalyst is a peroxide, an azo compound, a redox initiator or an azide.

In one embodiment of the present invention, the hardener is trimethylallyl isocyanate (TMAIC), triallyl isocyanurate (TAIC), 1,3-isopropenyl-α-methylstyrene/1,4-isopropenyl-α-methylstyrene (1,3-Isopropenyl-alpha-Methylstyrene/1,4-Isopropenyl-alpha-Methylstyrene, IP-AMS), 2,2'-diallyl bisphenol A (Di-ally BPA), divinylbenzene (DVB), 1,2-bis(p-vinylphenyl)ethane (BVPE).

In one embodiment of the present invention, the weight ratio of the hollow silica to the siloxane coupling agent is 1:10 to 1:25.

In one embodiment of the present invention, the alkaline solution is a 25% ammonium chloride solution.

In one embodiment of the present invention, the siloxane coupling agent is vinyl trimethoxysilane, vinyl triethoxysilane, p-phenylene trimethoxysilane, 3-methacrylate propyl methyl dimethoxy silane, 3-methacrylate propyl trimethoxy silane, 3-methacrylate propyl methyl diethoxy silane, 3-methacrylate propyl triethoxy silane or 3-acrylate propyl trimethoxy silane.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a prepreg sheet, which is formed by impregnating a reinforcing substrate into the aforementioned resin composition containing modified hollow microspheres.

In order to solve the above technical problems, another technical solution adopted by the present invention is to provide a printed circuit board, which includes a dielectric substrate layer and a conductive metal layer formed on the dielectric substrate layer, wherein the dielectric substrate layer is formed by the aforementioned prepreg sheet.

In one embodiment of the present invention, the dielectric constant of the dielectric substrate layer at 10 GHz is less than 2.9, and the dielectric loss of the dielectric substrate layer at 10 GHz is less than 0.003.

One of the beneficial effects of the present invention is that the resin composition, prepreg and printed circuit board containing modified hollow microspheres provided by the present invention can be prepared by "taking the total weight of the resin composition as 100 parts by weight, including 10 to 80 parts by weight of the modified hollow microspheres" and "the modified hollow microspheres are prepared by the following steps: (a) uniformly mixing hollow spherical silica, a siloxane coupling agent and an ethanol solution; (a) stirring for a first predetermined time; (b) adding an alkaline solution and continuing stirring for a second predetermined time; (c) centrifuging and pouring off the ethanol clarified liquid to take out the powder; and (d) drying the powder in a vacuum environment to obtain the "modified hollow microspheres" technical solution to improve the incompatibility and processability problems of hollow spherical silica in the existing resin composition after direct addition, and at the same time improve the electrical properties of the dielectric layer.

To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only used for reference and description and are not used to limit the present invention.

The following is an explanation of the implementation methods of the "resin composition containing modified hollow microspheres, prepreg and printed circuit board" disclosed in the present invention through specific concrete embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only for simple schematic illustrations and are not depicted according to actual dimensions. Please note in advance. The following implementation methods will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various elements or features, these elements or features should not be limited by these terms. These terms are mainly used to distinguish one element from another element, or one feature from another feature. In addition, the term "or" used herein may include any one or more combinations of the related listed items depending on the actual situation.

The manufacturing method of the modified hollow microspheres of the present invention is to first modify the surface of the hollow spherical silica with a silane coupling agent. Compared with the prior art of adding a silane coupling agent to bridge the hollow spherical silica with organic phase molecules, the modified hollow microspheres of the present invention have better compatibility and processability.

Referring to FIGS. 1 to 3 , the present invention provides a method for manufacturing modified hollow microspheres, which comprises at least the following steps: step S1: uniformly mixing hollow spherical silica, a siloxane coupling agent and an ethanol solution and stirring for a first predetermined time; step S2: adding an alkaline solution and continuously stirring for a second predetermined time; step S3: centrifuging and pouring out the ethanol clarified liquid to take out the powder; and step S4: drying the powder in a vacuum environment to obtain the modified hollow microspheres.

Specifically, step S1 to step S3 are performed at room temperature, which refers to 20 to 30 ^° C. The alkaline solution of step S2 can be an ammonium chloride solution, a sodium bicarbonate solution or a sodium hydroxide solution and an alkali gold group (IA) alkaline solution, and its pH value is 10 to 12 (for example, any positive integer between 10 and 12). In one embodiment of the present invention, the first predetermined time is 30 to 60 minutes, preferably 30 to 40 minutes (for example, any positive integer between 30 and 40). The second predetermined time is 24 to 36 hours, preferably 24 to 30 hours (for example, any positive integer between 24 and 30).

As shown in FIG. 2 , the present invention uses a siloxane coupling agent to modify hollow spherical silica. In FIG. 2 , R1, R2, and R3 can be C1-C12 alkyl or its C1-C12 isomers. In one embodiment of the present invention, the siloxane coupling agent may be vinyltrimethoxysilane, vinyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyl methyldimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-methacryloxypropyl methyldiethoxysilane, 3-methacryloxypropyl triethoxysilane or 3-acryloxypropyl trimethoxysilane. However, the above example is only a feasible embodiment and is not intended to limit the present invention.

Further, the weight ratio of hollow silica to siloxane coupling agent is 1:10 to 1:25, so as to obtain modified hollow silica having CH3-CH2, C-CH3, C=C and -OH functional groups at the same time. In a preferred embodiment of the present invention, the weight ratio of hollow silica to siloxane coupling agent is 1:10 to 1:20. For example, the weight ratio of hollow silica to siloxane coupling agent can be 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20. In a more preferred embodiment of the present invention, the weight ratio of hollow silica to siloxane coupling agent is 1:15.

Please refer to Figure 3. Before and after modification, the hollow silica has characteristic peaks at 825 and 1110 cm ^-1 , which are characteristic peaks of the hollow microsphere silane functional group (Si-O-Si). After modification, the hollow silica has characteristic peaks at 1420 and 2972 cm ^-1 , respectively, representing that it is connected to the CH3-CH2 and C-CH3 functional groups. After modification, the hollow silica has a characteristic peak at 1620 cm ^-1 , representing that it is connected to the vinyl double bond (C=C) functional group. After modification, the hollow silica has a characteristic peak at 3503 cm ^-1 , representing that it is connected to the hydrogen functional group (-OH). In other words, the hollow silica after modification of the present invention has CH3-CH2, C-CH3, C=C and -OH functional groups at the same time.

The method for preparing the modified hollow microspheres of the present invention is described in the following Synthesis Examples 1 to 10.

[Synthesis Example 1]

Place 1 g of hollow spherical silica, 15 ml of vinyl trimethoxysilane and 100 ml of ethanol in a 250 ml reaction bottle equipped with a thermometer and a stirrer, and stir at room temperature for 30 minutes. Subsequently, add 10 ml of 25% NH ₄ OH alkaline solution under continuous stirring, and stir at room temperature for 24 hours. Then, centrifuge at 2000 rpm for 3 times, remove the ethanol clarification liquid and take out the powder. Place the powder in a vacuum environment for 12 hours, and then perform a drying step at 100 ^o C for 2 hours to obtain the modified hollow microsphere powder (MS1-HS-SiO ₂ ).

[Synthesis Example 2]

The process conditions were the same as those of Synthesis Example 1, except that the siloxane coupling agent was changed to vinyl triethoxysilane to obtain a modified hollow microsphere powder (MS2-HS-SiO ₂ ).

[Synthesis Example 3]

The process conditions were the same as those in Synthesis Example 1, except that the siloxane coupling agent was changed to p-phenylethylenetrimethoxysilane to obtain a modified hollow microsphere powder (MS3-HS-SiO ₂ ).

[Synthesis Example 4]

The process conditions were the same as those in Synthesis Example 1, except that the siloxane coupling agent was changed to 3-methacrylatepropylmethyldimethoxysilane to obtain a modified hollow microsphere powder (MS4-HS-SiO ₂ ).

[Synthesis Example 5]

The process conditions were the same as those of Synthesis Example 1, except that the siloxane coupling agent was changed to 3-methacrylatepropyltrimethoxysilane to obtain a modified hollow microsphere powder (MS5-HS-SiO ₂ ).

[Synthesis Example 6]

The process conditions were the same as those in Synthesis Example 1, except that the siloxane coupling agent was changed to 3-methacrylatepropylmethyldiethoxysilane to obtain a modified hollow microsphere powder (MS6-HS-SiO ₂ ).

[Synthesis Example 7]

The process conditions were the same as those of Synthesis Example 1, except that the siloxane coupling agent was changed to 3-methacrylatepropyltriethoxysilane to obtain a modified hollow microsphere powder (MS7-HS-SiO ₂ ).

[Synthesis Example 8]

The process conditions were the same as those in Synthesis Example 1, except that the siloxane coupling agent was changed to 3-acrylic propyltrimethoxysilane to obtain a modified hollow microsphere powder (MS8-HS-SiO ₂ ).

[Synthesis Example 9]

Place 1 g of hollow spherical silica, 15 ml of vinyl trimethoxysilane and 100 ml of ethanol in a 250 ml reaction bottle equipped with a thermometer and a stirrer, and stir at room temperature for 30 minutes. Then, add 10 ml of 1% HCL acidic solution under continuous stirring, and stir at room temperature for 24 hours. Then, use a centrifuge to centrifuge 3 times at 2000 rpm, pour off the ethanol clarification liquid and take out the powder. Place the powder in a vacuum environment for 12 hours, and then perform a drying step at 100 ^o C for 2 hours to obtain the modified hollow microsphere powder (MS9-HS-SiO ₂ ).

[Synthesis Example 10]

The process conditions were the same as those of Synthesis Example 9, except that the siloxane coupling agent was changed to 3-acrylic propyltrimethoxysilane to obtain a modified hollow microsphere powder (MS10-HS-SiO ₂ ).

Furthermore, the present invention also provides a resin composition containing modified hollow microspheres, which includes 10 to 80 parts by weight of modified hollow microspheres, 5 to 60 parts by weight of polyphenylene ether resin, and 5 to 30 parts by weight of a hardener, based on the total weight of the resin composition being 100 parts by weight. If the content of the modified hollow microspheres is less than 10 parts by weight, the dielectric constant and dielectric loss cannot be effectively reduced. If the content of the modified hollow microspheres is higher than 80 parts by weight, the coating properties of the resin composition will be affected. If the content of the polyphenylene ether resin is lower than 5 parts by weight, the physical and mechanical properties, heat resistance and electrical insulation of the resin composition will be poor. If the content of the polyphenylene ether resin is higher than 60 parts by weight, the melt viscosity of the resin composition will be high and difficult to process. If the content of the hardener is less than 5 parts by weight, the resin will not be able to harden smoothly after coating. If the content of the hardener is higher than 30 parts by weight, the texture of the resin composition after curing will be too hard and brittle.

In a preferred embodiment of the present invention, the resin composition of the modified hollow microspheres includes 30 to 70 parts by weight of the modified hollow microspheres, 10 to 50 parts by weight of the polyphenylene ether resin, and 5 to 20 parts by weight of the hardener. In a more preferred embodiment of the present invention, the resin composition of the modified hollow microspheres includes 50 to 70 parts by weight of the modified hollow microspheres, 20 to 30 parts by weight of the polyphenylene ether resin, and 10 to 20 parts by weight of the hardener. In a still more preferred embodiment of the present invention, the weight ratio of the modified hollow microspheres, the polyphenylene ether resin, and the hardener is 65:24:11.

In detail, the hardener may be trimethylallyl isocyanate (TMAIC), triallyl isocyanurate (TAIC), 1,3-isopropenyl-alpha-methylstyrene/1,4-isopropenyl-alpha-methylstyrene (1,3-Isopropenyl-alpha-Methylstyrene/1,4-Isopropenyl-alpha-Methylstyrene, IP-AMS), 2,2'-diallyl bisphenol A (Di-ally BPA), divinylbenzene (DVB), 1,2-bis(p-vinylphenyl)ethane (BVPE). However, the above examples are only one possible embodiment and are not intended to limit the present invention.

The modified hollow microsphere powder prepared by the method of the present invention is mixed with a resin, a hardener, a catalyst, a reinforcing material, etc. to form a resin composition, that is, mixed with a homogenizer and dissolved or dispersed in a solvent to form a varnish for subsequent processing. For example, the catalyst can be a peroxide, an azo compound (such as α,α′-azobis(isobutyronitrile)), a redox initiator (such as a combination of peroxides, such as a combination of hydrogen peroxide and a ferrous salt) or a nitride (such as ethylene nitride). In one embodiment of the present invention, the catalyst may be a peroxide-based hardening accelerator, such as cyclohexanone peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, diisopropylbenzene peroxide, tert-butyl cumyl peroxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide, cumyl hydroperoxide, tert-butyl hydroperoxide. Preferably, the peroxide-based hardening accelerator is diisopropylbenzene peroxide (DCP) commercially available from Arkema.

The solvent can be any inert solvent that can dissolve or disperse the components of the resin composition but does not react with the components. The aforementioned solvents include but are not limited to: toluene, γ-butyrolactone, methyl ethyl ketone, cyclohexanone, butanone, acetone, xylene, methyl isobutyl ketone, N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methyl-pyrrolidone (NMP). Each solvent can be used alone or in combination. There is no special restriction on the amount of solvent used. In principle, as long as the components of the resin composition can be uniformly dissolved or dispersed therein, it can be used. In the following examples, a mixture of toluene, methyl ethyl ketone, and γ-butyrolactone is used as the solvent.

The present invention also provides a prepreg, which is prepared by impregnating or coating a substrate with a resin composition of modified hollow microspheres, and drying the impregnated or coated substrate. The impregnated or coated substrate can be dried at a temperature of 80°C to 180°C for 1 to 10 minutes (e.g., any positive integer between 1 and 10) to obtain a semi-cured prepreg. In one embodiment of the present invention, 2116 reinforced glass fiber cloth is used as a substrate (reinforcement material), and is heated and dried at 175°C for 2 to 15 minutes (e.g., any positive integer between 2 and 15) to obtain a semi-cured prepreg.

Furthermore, the above-mentioned prepregs and metal foils can be laminated to produce metal foil laminates and printed circuit boards. In one embodiment of the present invention, four prepregs impregnated or coated with the above-mentioned resin composition can be laminated, and a 0.5 ounce copper foil is laminated on the outermost layers of both sides, and then placed in a hot press for high-temperature hot pressing and curing to produce a printed circuit board. Specifically, the hot pressing conditions are: heating the temperature to 200°C to 220°C (e.g., any positive integer between 200 and 220) at a heating rate of 3.0°C/min, and hot pressing at the temperature for 180 minutes at a full pressure of 15 kg/cm2 (initial pressure of 8 kg/cm2).

Next, the dielectric substrate layer was subjected to glass transition temperature (Tg), coefficient of thermal expansion (CTE), dielectric constant (Dk), dielectric loss (Df) and compatibility property tests, and the components of the resin composition and the test results are listed in Table 1. In Table 1, EX1-EX8 represent Examples 1 to 8, and C1-C12 represent Comparative Examples 1 to 12.

[CTE test]

According to IPC-TM-650 2.4.24.5, a thermal mechanical analyzer (TMA) is used to measure the coefficient of thermal expansion (CTE) change rate in the Z-axis direction (total z-CTE) of the sample at a temperature below Tg.

[Compatibility test]

Place the powder filler in a varnish solution and leave it at room temperature for 2 hours before observing whether the powder is suspended. If it is suspended on the surface, mark it with (X); otherwise, mark it with (O).

[Dielectric constant, dielectric loss test]

The laminated substrate was removed from the hot press and the copper foil was removed by etching to form a test specimen; the dielectric constant and dissipation factor were tested at 10 GHz using the clamped stripline test method described in IPC-TM-650 2.5.5.5.1.

The composition and physical property measurement results of the embodiment of the present case are shown in Table 1, and the composition and physical property measurement results of the comparative example are shown in Table 2. The contents in Table 1 and Table 2 are expressed in parts by weight. The composition of the embodiment of the present case is based on the total volume of all components as 100%, of which 50% by volume is hollow microspheres, 25% by volume is reinforcing material, and 25% by volume is resin, catalyst and flame retardant.

Table 1 Embodiment 1 2 3 4 5 6 7 8 Modified hollow microspheres MS1-HS- _SiO2 65 MS2-HS-SiO2 65 MS3-HS- _SiO2 65 MS4-HS- _SiO2 65 MS5-HS- _SiO2 65 MS6-HS- _SiO2 65 MS7-HS- _SiO2 65 MS8-HS- _SiO2 65 MS9-HS- _SiO2 MS10-HS- _SiO2 HS-SiO ₂ Glass hollow microspheres Spherical Silica Powder silane 1 silane 4 Resin Polyphenylene ether resin PPO twenty four twenty four twenty four twenty four twenty four twenty four twenty four twenty four Hardener TMAIC 11 11 11 11 11 11 11 11 Polybutadiene 5 5 5 5 5 5 5 5 Flame retardant 5 5 5 5 5 5 5 5 Catalyst Peroxide 0.75 0.75 0.75 0.75 0.75 0.75 0.75 0.75 Reinforcement material EG-Glass Cloth 15 15 15 15 15 15 15 15 Measuring physical properties Tg(TMA)℃ 225 220 218 223 215 210 222 204 CTE(ppm/℃) 0.64 0.62 0.66 0.71 0.6 0.65 0.7 0.64 Dielectric constant (10GHz) 2.84 2.81 2.8 2.79 2.85 2.81 2.8 2.87 Dielectric loss (10GHz) 0.003 0.0028 0.0027 0.0028 0.0026 0.0028 0.0025 0.0028 Compatibility O O O O O O O O

Table 2 C1 C2 C3 C4 C5 C6 MS1-HS- _SiO2 MS2-HS- _SiO2 MS3-HS- _SiO2 MS4-HS- _SiO2 MS5-HS- _SiO2 MS6-HS- _SiO2 MS7-HS- _SiO2 MS8-HS- _SiO2 MS9-HS- _SiO2 65 MS10-HS- _SiO2 65 HS-SiO ₂ 65 65 65 Glass hollow microspheres 65 Spherical Silica Powder silane 1 5 silane 4 5 Resin Polyphenylene ether resin PPO twenty four twenty four twenty four twenty four twenty four twenty four Hardener TMAIC 11 11 11 11 11 11 Polybutadiene 5 5 5 5 5 5 Flame retardant 5 5 5 5 5 5 Catalyst Peroxide 0.75 0.75 0.75 0.75 0.75 0.75 Reinforcement EG-Glass Cloth 15 15 15 15 15 15 Measuring physical properties Tg(TMA)℃ 224 205 216 220 209 217 CTE(ppm/℃) 0.63 0.65 0.63 0.64 0.71 0.59 Dielectric constant (10GHz) 3 3.1 2.88 2.86 2.86 2.85 Dielectric loss (10GHz) 0.09 0.01 0.003 0.0033 0.0032 0.003 Compatibility O O X X X X

Table 2 (continued) C7 C8 C9 C10 C11 C12 MS1-HS- _SiO2 MS2-HS- _SiO2 MS3-HS- _SiO2 MS4-HS- _SiO2 MS5-HS- _SiO2 MS6-HS- _SiO2 MS7-HS- _SiO2 MS8-HS- _SiO2 MS9-HS- _SiO2 MS10-HS- _SiO2 HS-SiO ₂ Glass hollow microspheres 30 30 30 Spherical Silica Powder 65 30 30 silane 1 silane 4 Resin Polyphenylene ether resin PPO twenty four twenty four twenty four twenty four twenty four twenty four Hardener TMAIC 11 11 11 11 11 11 Polybutadiene 5 5 5 5 5 5 Flame retardant 5 5 5 5 5 5 Catalyst Peroxide 0.75 0.75 0.75 0.75 0.75 0.75 Reinforcement material EG-Glass Cloth (25% volume percentage) 15 15 15 15 15 15 Measuring physical properties Tg(TMA)℃ 228 216 210 213 217 200 CTE(ppm/℃) 0.6 0.64 0.64 0.62 0.6 0.61 Dielectric constant (10GHz) 3.3 2.9 3.15 2.8 3.12 2.8 Dielectric loss (10GHz) 0.004 0.003 0.0035 0.003 0.0034 0.003 Compatibility O X X X X X

In Table 1 and Table 2, silane 1 is vinyltrimethoxysilane; silane 4 is 3-methacryloxypropyl methyldimethoxysilane. The peroxide is diisopropyl peroxide (DCP) commercially available from Arkema.

As shown in Table 1, the modified hollow microspheres of the present invention have excellent compatibility with other materials of the dielectric substrate, and the use of the modified hollow microspheres of the present invention can make the dielectric constant of the dielectric substrate at 10 GHz less than 2.9, and the dielectric loss of the dielectric substrate layer at 10 GHz less than 0.003.

The modified hollow microspheres of the present invention are manufactured in an alkaline environment to obtain a lower dielectric constant and dielectric loss. For example, in Comparative Examples C1 and C2, although the siloxane coupling agent used is the same as that of the embodiment of the present invention, the modified hollow microspheres of Comparative Examples C1 and C2 are modified in an acidic environment (pH 3-5.5), resulting in poor electrical properties of the modified hollow microspheres.

In addition, although the unmodified hollow microspheres used in Comparative Examples C3 to C5 also have lower dielectric constants and dielectric losses, their compatibility is poor. Comparative Examples C6 and C7 use glass hollow microspheres and spherical silica, which have poor compatibility and poor electrical properties, respectively.

In addition, Comparative Examples C8 to C12 show that even if glass hollow microspheres or spherical silica are mixed with the modified hollow microspheres of the present invention, there are still disadvantages such as poor compatibility and poor electrical properties. Therefore, the modified hollow microspheres of the present invention need to be used in a specific amount to achieve the effect of taking into account both compatibility and electrical properties.

[Beneficial Effects of Embodiments]

One of the beneficial effects of the present invention is that the resin composition, prepreg and printed circuit board containing modified hollow microspheres provided by the present invention can be prepared by "taking the total weight of the resin composition as 100 parts by weight, including 10 to 80 parts by weight of the modified hollow microspheres" and "the modified hollow microspheres are prepared by the following steps: (a) uniformly mixing hollow spherical silica, a siloxane coupling agent and an ethanol solution; (a) stirring for a first predetermined time; (b) adding an alkaline solution and continuing stirring for a second predetermined time; (c) centrifuging and pouring off the ethanol clarified liquid to take out the powder; and (d) drying the powder in a vacuum environment to obtain the "modified hollow microspheres" technical solution to improve the incompatibility and processability problems of hollow spherical silica in the existing resin composition after direct addition, and at the same time improve the electrical properties of the dielectric layer.

Furthermore, the resin composition containing modified hollow microspheres provided by the method of the present invention has low dielectric properties and excellent mechanical properties. Therefore, it has a wide range of applications in the fields of electronics, aerospace, etc., and is particularly suitable for the manufacture of prepregs and printed circuit boards.

The contents disclosed above are only preferred feasible embodiments of the present invention and are not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made using the contents of the specification and drawings of the present invention are included in the scope of the patent application of the present invention.

S1~S4: steps.

FIG1 is a flow chart of the method for manufacturing modified hollow microspheres of the present invention.

FIG. 2 is a schematic diagram of the manufacturing method of the modified hollow microspheres of the present invention.

Figure 3 compares the Fourier transform infrared spectra of hollow microspheres before and after modification.

S1~S4: Steps

Claims (10)

A resin composition containing modified hollow microspheres, with the total weight of the resin composition being 100 parts by weight, comprises: 10 to 80 parts by weight of modified hollow microspheres, wherein the modified hollow microspheres contain a functional group selected from the group consisting of CH3-CH2, C-CH3, C=C, -OH and combinations thereof; 5 to 60 parts by weight of polyphenylene ether resin; and 5 to 30 parts by weight of a hardener; wherein the modified hollow microspheres are prepared by the following steps: (a) uniformly mixing hollow spherical silica, a siloxane coupling agent and an ethanol solution and stirring for a first predetermined time; (b) adding an alkaline solution and continuing stirring for a second predetermined time; (c) centrifuging and pouring off the ethanol clarified liquid to take out the powder; and (d) drying the powder in a vacuum environment to obtain the modified hollow microspheres. The resin composition containing modified hollow microspheres as described in claim 1, wherein the resin composition further comprises 0.1 to 5 parts by weight of a catalyst. A resin composition containing modified hollow microspheres as described in claim 2, wherein the catalyst is a peroxide, an azo compound, a redox initiator or an azide. The resin composition containing modified hollow microspheres as described in claim 1, wherein the hardener is trimethylallyl isocyanate (TMAIC), triallyl isocyanurate (TAIC), 1,3-isopropenyl-α-methylstyrene/1,4-isopropenyl-α-methylstyrene (1,3-Isopropenyl-alpha-Methylstyrene/1,4-Isopropenyl-alpha-Methylstyrene, IP-AMS), 2,2'-diallylbisphenol A (Di-ally BPA), divinylbenzene (DVB), 1,2-bis(p-vinylphenyl)ethane (BVPE). The resin composition containing modified hollow microspheres as described in claim 1, wherein the weight ratio of the hollow silica to the siloxane coupling agent is 1:10 to 1:25. The resin composition containing modified hollow microspheres as described in claim 1, wherein the alkaline solution is a 25% ammonium chloride solution. The resin composition containing modified hollow microspheres as described in claim 1, wherein the siloxane coupling agent is vinyl trimethoxysilane, vinyl triethoxysilane, p-phenylene trimethoxysilane, 3-methacrylate propyl methyl dimethoxy silane, 3-methacrylate propyl trimethoxy silane, 3-methacrylate propyl methyl diethoxy silane, 3-methacrylate propyl triethoxy silane or 3-acrylate propyl trimethoxy silane. A prepreg sheet is formed by impregnating a reinforcing base material into a resin composition containing modified hollow microspheres as described in any one of claims 1 to 7. A printed circuit board comprises a dielectric substrate layer and a conductive metal layer formed on the dielectric substrate layer, wherein the dielectric substrate layer is formed by the prepreg sheet as described in claim 8. A printed circuit board as described in claim 9, wherein the dielectric constant of the dielectric substrate layer at 10 GHz is less than 2.9, and the dielectric loss of the dielectric substrate layer at 10 GHz is less than 0.003.

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