CN111801808A

CN111801808A - Preparation method of spherical or angular powder filler, spherical or angular powder filler obtained by preparation method and application of spherical or angular powder filler

Info

Publication number: CN111801808A
Application number: CN201980016674.1A
Authority: CN
Inventors: 陈树真; 李锐; 唐成; 丁烈平; 陈晨
Original assignee: Zhejiang Sanshi New Material Technology Co Ltd
Current assignee: Zhejiang Sanshi New Material Technology Co Ltd
Priority date: 2019-02-22
Filing date: 2019-12-05
Publication date: 2020-10-20
Anticipated expiration: 2039-12-05
Also published as: CN111801296A; CN111819248A; WO2020168719A1; CN111819247A; WO2020168542A1; CN111819248B; KR20210125546A; CN111801808B; KR20210127198A

Abstract

The invention relates to a preparation method of spherical or angular powder filler, and provides spherical or angular siloxane containing T units, wherein the T units are R₁SiO₃‑，R₁An organic group which is a hydrogen atom or an independently selected carbon atom of 1 to 18; and carrying out heat treatment on the spherical or angular siloxane under the condition of inert gas atmosphere or atmospheric atmosphere, wherein the heat treatment temperature is more than 250 ℃ and less than 650 ℃, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain the spherical or angular powder filler, in the T unit of the spherical or angular powder filler, the content of a unit without hydroxyl groups in the total unit is more than or equal to 95%, and the content of a unit containing one hydroxyl group in the total unit is less than or equal to 5%. The invention also provides the spherical or angular powder filler obtained by the preparation method. The invention also provides a spherical or angular powder according to the aboveApplication of bulk filler. The spherical or angular powder filler provided by the invention has low dielectric rate, low water absorption and low radioactivity.

Description

Preparation method of spherical or angular powder filler, spherical or angular powder filler obtained by preparation method and application of spherical or angular powder filler

Technical Field

The invention relates to semiconductor packaging, in particular to a preparation method of a spherical or angular powder filler, the spherical or angular powder filler obtained by the preparation method and application of the spherical or angular powder filler.

Background

In the packaging process of the semiconductor back-end process, packaging materials such as a plastic packaging material, a surface mount adhesive, a bottom pouring material, a chip carrier and the like are required. In addition, when passive components, semiconductor components, electro-acoustic devices, display devices, optical devices, radio frequency devices, etc. are assembled into devices, circuit boards (high density interconnect (HDI)), high frequency high speed boards, mother boards, etc. are usedThe organic polymer consists of molecules and fillers, wherein the fillers are mainly angular or spherical silica, and the main function of the fillers is to reduce the thermal expansion coefficient of the organic polymer. The existing filler is selected from spherical or angular silica for tight filling grading, and the chemical structure of the silica is Si Q unit, namely SiO₄-。

On the other hand, with the progress of technology, the frequency of signals used in semiconductors is becoming higher, and the filler is required to have a low dielectric constant in order to increase the signal transmission speed and reduce the loss. On the other hand, the dielectric constant of the material is basically determined by the chemical composition and structure of the material, and the silica has its inherent dielectric value, so the conventional filler cannot meet the requirement of lower dielectric constant.

Also, as the technology advances, the semiconductor integration becomes higher and smaller in size, which requires the filler to have high purity without conductive foreign substances and without coarse particles. However, it is difficult to avoid the mixing of coarse particles and conductive foreign substances in the conventional spherical or angular silica. Further, the coarse particles and conductive foreign matter are mixed once and cannot be removed by dry method basically. Therefore, the conventional filler cannot meet the requirements of no conductive foreign matter and no coarse particles.

For semiconductor memories, a filler with low activity is required. However, the purity of the present spherical or angular silica depends to a large extent on the purity of the natural mineral itself. Thus, the existing fillers cannot meet the requirement of low radioactivity.

Disclosure of Invention

The invention aims to provide a preparation method of a spherical or angular powder filler, the spherical or angular powder filler obtained by the preparation method and application thereof, and the filler provided by the preparation method has low dielectric constant, no conductive foreign matters, no coarse particles and low radioactivity.

The invention provides a preparation method of spherical or angular powder filler, which comprises the following steps: s1 providing a spherical or angular siloxane comprising T units, wherein T units R₁SiO₃-，R₁An organic group which is a hydrogen atom or an independently selected carbon atom of 1 to 18; and S2 in an inert gas atmosphereOr under the atmospheric atmosphere, the spherical or angular siloxane is subjected to heat treatment, the heat treatment temperature is more than 250 ℃ and less than 650 ℃, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain the spherical or angular powder filler, in the T unit of the spherical or angular powder filler, the content of a unit without hydroxyl groups in the total unit is more than or equal to 95%, and the content of a unit containing one hydroxyl group in the total unit is less than or equal to 5%.

Unlike the existing silica fillers containing only Q units, the silica of the spherical or angular powder filler of the invention comprises T units, by introducing an organic radical R₁Greatly reducing the dielectric rate. By performing the heat treatment under an inert gas atmosphere or an atmospheric atmosphere. In order to avoid oxidation of the organic group, the heating temperature under the atmospheric condition is preferably lower than 300 degrees, and the heating time is preferably longer than 20 hours. The heating temperature under the inert gas atmosphere such as nitrogen can be as high as 650 ℃, and the heating time can be shorter when the temperature is high. The present invention specifically limits the heat treatment temperature to 250 ℃ or higher to promote the condensation reaction of the silicon hydroxyl group. Although the condensation is more rapid and sufficient as the temperature is higher, the present invention specifically limits the heat treatment temperature to 650 degrees or less to avoid thermal decomposition of carbosilane itself. The powder filler obtained after heat treatment is prepared by²⁹Characterization by Si NMR: the peak in the range of-30 to-80 ppm corresponds to T units, the area in this range being the total area S; the peak in the range of-42 to-52 ppm (excluding-52 ppm) corresponds to the T unit containing two hydroxyl groups, i.e., T₁The area within the range is S₁(ii) a The peak in the range of-52 to-62 ppm (excluding-62 ppm) corresponds to the T unit containing one hydroxyl group, i.e., T₂The area within the range is S₂(ii) a The peak in the range of-62 to-75 ppm corresponds to the T unit containing no hydroxyl group, i.e., T₃The area within the range is S₃. S of the spherical or angular powder filler of the invention₃/S≥95％，S₂/S≤5％，S₁Substantially equal to 0.

Preferably, the spherical or angular siloxane provided in step S1 further contains Q units, D units, and/or M units, wherein Q units ═ SiO units₄-, D unit ═ R₂R₃SiO₂-, M units ═ R₄R₅R₆SiO₂-，R₂，R₃，R₄，R₅，R₆Each hydrogen atom or an independently selected hydrocarbyl group of carbon atoms 1 to 18. It is understood that the introduction of Q units can reduce the thermal expansion coefficient, but the introduction amount is adjusted as necessary because the dielectric constant and dielectric loss are increased. The introduction of D or M units can reduce the dielectric constant and dielectric loss, but the introduction amount is adjusted as necessary because the coefficient of thermal expansion increases. Preferably, the sum of the Q units, D units, and/or M units in the spherical or angular siloxane is 20 weight percent or less.

Preferably, the spherical or angular siloxane provided in step S1 further contains silica particles. It is understood that the introduction of silica particles (also referred to as fine silica powder) can reduce the thermal expansion coefficient, but the amount of introduction is adjusted as necessary because the dielectric constant and dielectric loss are increased. Preferably, the total content of silica particles in the spherical or angular siloxane is 70% by weight or less.

Preferably, in the step S2, the heat treatment is performed by electrothermal heating or microwave heating, which causes Si — OH in spherical or angular siloxane to be condensed to produce a SiOSi structure, and the equation of the condensation reaction is as follows:

wherein R ', R ", R'" are hydrogen atoms or independently selected organic radicals R of carbon atoms 1 to 18₁(also known as hydrocarbyl).

Preferably, the heat treatment temperature in step S2 is 250-650 degrees. It will be appreciated that the higher the temperature the shorter the time required, and the lower the temperature the longer the time required. In a preferred embodiment, the time of the heat treatment is between 1 and 72 hours.

Preferably, the preparation method further comprises adding a treating agent to carry out surface treatment on the polysiloxane so as to improve the affinity of the filler and the resin.

Preferably, the treating agent comprises a silane coupling agent which is (R)₇)_a(R₈)_bSi(M)_4-a- _b，R₇，R₈Is an independently selectable hydrocarbon group of carbon atoms 1 to 18, a hydrogen atom, or a hydrocarbon group of carbon atoms 1 to 18 substituted with a functional group selected from at least one of the following organofunctional groups: vinyl, allyl, styryl, epoxy, aliphatic amino, aromatic amino, methacryloxypropyl, acryloxypropyl, ureidopropyl, chloropropyl, mercaptopropyl, polysulfide, isocyanatopropyl; m is a hydrocarbyloxy group having 1 to 18 carbon atoms or a halogen atom, a is 0, 1, 2 or 3, b is 0, 1, 2 or 3, and a + b is 1, 2 or 3.

Preferably, the silane coupling agent is selected from silane coupling agents having radical polymerization reaction, such as vinyl silane coupling agents and the like; silane coupling agents such as epoxy silane coupling agents, aminosilane coupling agents, etc. which react with the epoxy resin; hydrocarbyl silane coupling agents having high affinity with hydrophobic resins, such as dimethyldimethoxysilane, diphenyldimethoxysilane, phenylsilane coupling agents, long-chain alkylsilane coupling agents, and the like. More preferably, the silane coupling agent is selected from at least one of the following coupling agents: dimethyldimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane.

Preferably, the treating agent comprises a disilazane which is (R)₉R₁₀R₁₁)SiNHSi(R₁₂R₁₃R₁₄)，R₉，R₁₀，R₁₁，R₁₂，R₁₃，R₁₄Is an independently selected hydrocarbon group of carbon atoms 1 to 18 or a hydrogen atom. More preferably, the disilazane is hexamethyldisilazane.

Preferably, the preparation method comprises removing coarse large particles of 75 microns or more from spherical or angular powder fillers using dry or wet sieving or inertial classification. Preferably, coarse and large particles of 55 μm or more in the spherical or angular powder filler are removed. Preferably, coarse large particles of 45 μm or more in the spherical or angular powder filler are removed. Preferably, coarse and large particles of 20 μm or more in the spherical or angular powder filler are removed. Preferably, coarse large particles of 10 microns or more in spherical or angular fillers are removed. Preferably, coarse large particles of 5 microns or more in the spherical or angular powder filler are removed. Preferably, coarse large particles of 3 μm or more in the spherical or angular powder filler are removed. Preferably, coarse particles of 1 micron or more in the spherical or angular powder filler are removed.

The invention also provides the spherical or angular powder filler obtained by the preparation method, and the particle size of the spherical or angular powder filler is 0.1-50 microns. Preferably, the particle size is 0.5 to 30 microns. In addition, the 200-degree volatile moisture content of the spherical or angular powder filler is less than or equal to 0.1 percent. Specifically, the moisture content of the powder of the present invention can be characterized by the loss of moisture after heating at 200 degrees for 2 hours. It is known that the water absorption of the filler is related to the dielectric loss, and the greater the water absorption, the greater the dielectric loss. The spherical or angular powder filler of the invention contains few hydroxyl polar groups, has low water absorption, has the water weight loss of less than or equal to 0.1 percent after being heated for 2 hours at 200 ℃, and is suitable for semiconductor packaging or circuit boards and other applications with low dielectric loss requirements.

The measurement results show that the dielectric constant of the spherical or angular powder filler of the present invention at 500MHz is only 2.5 to 2.9 and less than 3, while the dielectric constant of the conventional silica filler of Q unit is about 3.8 to 4.5. Therefore, the spherical or angular powder filler has greatly reduced dielectric constant and can meet the material requirement of high-frequency signals in the 5G era.

The invention also provides an application of the spherical or angular powder filler, wherein the spherical or angular powder fillers with different grain diameters are tightly filled and graded in resin to form a composite material. Preferably, the composite material is suitable for semiconductor packaging materials, circuit boards and intermediate semi-finished products thereof. Preferably, the packaging material is a molding compound, a chip adhesive, an underfill material, or a chip carrier. The plastic package material is a plastic package material in a DIP packaging form, a plastic package material in an SMT packaging form, a plastic package material in a MUF, FO-WLP or FCBGA form. Preferably, the circuit board is an HDI, high frequency high speed board, or motherboard.

It is known that the dielectric constant of the composite material can be approximately calculated by the following formula 1:

formula 1: log ═ V₁×log₁+V₂×log₂

: the dielectric rate of the composite material; v₁: volume fraction of resin;₁: the dielectric constant of the resin; v₂: the volume fraction of filler;₂: the dielectric constant of the filler.

Therefore, by adjusting the volume fractions of the resin and the spherical or angular powder filler, the dielectric constant required by the composite material can be designed as required to form the packaging material, the circuit board and the intermediate semi-finished product thereof.

In summary, the process for the preparation of spherical or angular powder fillers according to the invention results in fillers having a low dielectric constant. Furthermore, since the raw materials for the production process are all organic materials, the conventionally used angular crushed quartz is not involved, and the filler can be purified by an industrial method such as distillation, and the spherical or angular powder filler thus formed does not contain radioactive elements such as uranium and thorium, and thus satisfies the requirements of no conductive foreign matter, no coarse particles, and low radioactivity. In addition, the preparation method of the invention can properly adjust the synthesis parameters to prepare the spherical or angular powder filler with the particle size of 0.1 to 50 microns.

Detailed Description

The following provides a detailed description of the preferred embodiments of the present invention.

The detection methods referred to in the following examples include:

the average particle diameter was measured by means of a laser particle size distribution apparatus LA-700 from HORIBA. The solvent is isopropanol;

the uranium, content was determined by Agilent's model 7700X ICP-MS. The sample preparation method comprises the steps of burning at 800 ℃, and then fully dissolving the sample with hydrofluoric acid;

the weight loss was weighed with an analytical balance after heating at 200 ℃ for 2 hours, and the heated sample was weighed after cooling in a dry air container. The heated sample, when left in the atmosphere, absorbed water and gained weight, indicating that the heating weight loss is the water absorbed by the polysiloxane. The sample before testing is placed in the atmosphere for more than 1 hour, so that the sample adsorbs moisture in the atmosphere and reaches a saturated state. The atmospheric atmosphere referred to herein means a natural atmospheric atmosphere in subtropical regions.

The content of Q, T, D, M units being derived from solids²⁸The peak integral area (Q unit) in the range of-80 to-120 ppm, the peak integral area (T unit) in the range of-30 to-80 ppm, the peak integral area (D unit) in the range of 10 to-30 ppm, and the peak integral area (M unit) in the range of +20 to-10 ppm on the Si-NMR spectrum. ECS-400 by JEOL using NMR; reference to the literature: separation and Purification Technology Volume 25, Issues 1-3, 1October 2001, Pages 391-. T is₁，T₂，T₃The percentage content of (A) is as follows: the area in the range of-42 to-52 ppm (excluding-52 ppm) is assigned to T₁The area in the range of-52 to-62 ppm (excluding-62 ppm) is assigned to T₂And the area in the range of-62 to-75 ppm is assigned to T₃And the integrated area of the peak in the range of-30 to-80 ppm is calculated as the denominator.

The dielectric constant was measured by using a KEYCOM perturbation system sample hole-locked cavity resonance method dielectric constant measuring apparatus Model No. DPS 18.

Herein, "degree" refers to "degrees celsius", i.e. celsius.

Reference is made to the methods of spherical Silicone micropowder, Weak WeChat, Silicone materials, 2007, 21(5)294 & lt 299 & gt and PCT/CN2018/124685 to prepare spherical siloxanes of different compositions for use in the examples and comparative examples for subsequent heat treatment.

Adding methyl trichlorosilane or methyltrimethoxysilane into water to obtain white precipitate. After washing with deionized water, the precipitate was ground to 2 μm fine powder with a sand mill for examples and comparative examples to conduct the subsequent heat treatment.

In addition, methyl trichlorosilane or methyl trimethoxy silane and silicon dioxide are mixed and then added into water to obtain white precipitate. After washing with deionized water, the precipitate was ground to 2 μm fine powder with a sand mill for examples and comparative examples to conduct the subsequent heat treatment.

Example 1

Will T unit (R)₁Methyl group) 100%, and spherical siloxane having an average particle diameter of 2 μm was heat-treated at different temperatures in an air or nitrogen atmosphere. The treated powder was mixed with 1% vinyltrimethoxysilane and then heated at 130 ℃ for 3 hours, and then large particles of 10 μm or more were removed by cyclone separation to obtain examples and comparative examples. The results of the analysis of the samples are shown in Table 1.

TABLE 1

Obviously, the dielectric constant of the example samples obtained according to examples 1 to 3 is less than 3, and the 200-degree evaporated water content is less than 0.1%, so that the requirement of low dielectric constant (small signal delay) of the filler in the 5G period is met. The T2 content of comparative example 1 and comparative example 2 was too high, and the water absorption and the dielectric constant were too high; the T units of comparative example 3 were all oxidized to Q units (i.e., to silica) with too high an inductivity, which is outside the scope of the present invention.

Example 2

Will T unit (R)₁Methyl) 97%, Q units 3% of spherical siloxane with an average particle size of 2 μm was heat treated under nitrogen atmosphere. The treated powder was subjected to surface treatment without using a treating agent, and large particles of 10 μm or more were removed by cyclone separation to obtain samples of examples and comparative examples. The results of the analysis of the samples are shown in Table 2.

TABLE 2

It is apparent that the example sample obtained in example 4 has an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, and thus satisfies the requirement of low electric induction rate (small signal delay) of the filler in the age of 5G.

Example 3

Will T unit (R)₁Methyl) 97%, D units (R)₂，R₃All methyl) 3% of spherical siloxane with an average particle size of 2 μm was heat treated in air or nitrogen atmosphere. The treated powder was mixed with 2% hexamethyldisilazane and then heated at 130 ℃ for 3 hours, and then the powder was separated by cyclone to remove large particles of 10 μm or more. The results of the analysis of the samples are shown in Table 3.

TABLE 3

It is apparent that the example sample obtained in example 5 has an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, and thus satisfies the requirement of low electric induction rate (small signal delay) of the filler in the age of 5G.

Example 4

Mixing methyltrimethoxysilane and silicon dioxide, and adding into water to obtain white precipitate. Washing with deionized water, and grinding the precipitate to 2 μm fine powder with a sand mill.

Will T unit (R)₁Methyl) 70%, 30% of fine silica powder (fumed silica) and angular siloxane having an average particle diameter of 2 μm were heat-treated in air or nitrogen atmosphere. The treated powder was mixed with 5% dimethyldimethoxysilane and heated at 130 ℃ for 3 hours, and then large particles of 10 μm or more were removed by cyclone separation to obtain an example. The results of the analysis of the samples are shown in Table 4.

TABLE 4

It is apparent that the example sample obtained in example 6 has an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, and thus satisfies the requirement of low electric induction rate (small signal delay) of the filler in the age of 5G.

Example 5

Will T unit (R)₁Methyl) 100% of spherical siloxane having an average particle diameter of 2 μm was heat-treated under a nitrogen atmosphere. The treated powder was treated with 2% vinyltrimethoxysilane, mixed with 1% hexamethyldisilazane, and heated at 130 ℃ for 3 hours, and then the powder was separated by cyclone to remove large particles having a size of 10 μm or more, to obtain example 7, and the analysis results are shown in Table 5. Will T unit (R)₁Methyl) 100% of spherical siloxane having an average particle diameter of 2 μm was heat-treated under a nitrogen atmosphere. The treated powder was treated with a mixture of 2% methyltrimethoxysilane and 1% hexamethyldisilazane, and then heated at 130 ℃ for 3 hours, and the powder was subjected to cyclone separation to remove large particles having a size of 10 μm or more, to obtain example 8, and the analysis results are shown in Table 5.

TABLE 5

It is apparent that the examples obtained according to examples 7 to 8 have an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, thereby satisfying the requirement of low electric induction rate (small signal delay) of the filler at the time of 5G.

Example 6

Will T unit (R)₁Methyl group) 100%, and spherical siloxanes having different average particle diameters were heat-treated under a nitrogen atmosphere for different periods of time to give example samples. The results of the analysis of the samples are shown in Table 7.

TABLE 6

It is apparent that the examples obtained according to examples 9 to 13 have an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, thereby satisfying the requirement of low electric induction rate (small signal delay) of the filler at the time of 5G. In addition, the powders of examples 9-13 were graded to give low viscosity, tightly packed powders.

Example 7

Adding methyl trichlorosilane into water to obtain white precipitate. Washing with deionized water, and grinding the precipitate to 2 μm fine powder with a sand mill. Filtering, drying and then carrying out heat treatment in a nitrogen atmosphere. The treated powder was mixed with 4% hexamethyldisilazane and then heated at 130 ℃ for 3 hours, and then large particles of 10 μm or more were removed from the powder by cyclone separation to obtain an example sample. The results of the analysis of the samples are shown in Table 8.

TABLE 7

It is apparent that the example sample obtained in example 14 has an electric induction rate of less than 3 and 200-degree evaporated water of less than 0.1%, and thus satisfies the requirement of low electric induction rate (small signal delay) of the filler in the age of 5G.

It should be understood that the example samples obtained in examples 1-14 above may be subjected to a vertex cutting step to remove coarse particles. Specifically, coarse particles of 75, 55, 45, 20, 10, 5, 3, or 1 μm or more in the spherical powder filler are removed as necessary according to the size of the semiconductor chip by a method such as dry or wet sieving or inertial classification. Further, it was found by ICP-MS detection of the samples of examples obtained in examples 1 to 14, which were dissolved in hydrofluoric acid, that the contents of uranium and thorium were 0.5ppb or less, respectively.

The above embodiments are merely preferred embodiments of the present invention, which are not intended to limit the scope of the present invention, and various changes may be made in the above embodiments of the present invention. All simple and equivalent changes and modifications made according to the claims and the content of the specification of the present application fall within the scope of the claims of the present patent application. The invention has not been described in detail in order to avoid obscuring the invention.

Claims

A preparation method of spherical or angular powder filler is characterized by comprising the following steps:

s1 providing a spherical or angular siloxane comprising T units, wherein T units R₁SiO₃-，R₁An organic group which is a hydrogen atom or an independently selected carbon atom of 1 to 18; and

s2, heat treating the spherical or angular siloxane under the condition of inert gas atmosphere or atmospheric atmosphere, wherein the heat treatment temperature is more than 250 ℃ and less than 650 ℃, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain the spherical or angular powder filler, in the T unit of the spherical or angular powder filler, the content of a unit without hydroxyl groups in the total unit is more than or equal to 95%, and the content of a unit containing one hydroxyl group in the total unit is less than or equal to 5%.
The process according to claim 1, wherein the spherical or angular siloxane further comprises Q units, D units, and/or M units, wherein Q units are SiO units₄-, D unit ═ R₂R₃SiO₂-, M units ═ R₄R₅R₆SiO₂-，R₂，R₃，R₄，R₅，R₆Each hydrogen atom or an independently selected hydrocarbyl group of carbon atoms 1 to 18.
The method according to claim 1, wherein the spherical or angular silicone further contains silica particles.
The method of claim 1, further comprising adding a treating agent to surface the powder fillerA treatment comprising a silane coupling agent and/or a disilazane; the silane coupling agent is (R)₇)_a(R₈)_bSi(M)_4-a-b，R₇，R₈Is an independently selectable hydrocarbon group of carbon atoms 1 to 18, a hydrogen atom, or a hydrocarbon group of carbon atoms 1 to 18 substituted with a functional group selected from at least one of the following organofunctional groups: vinyl, allyl, styryl, epoxy, aliphatic amino, aromatic amino, methacryloxypropyl, acryloxypropyl, ureidopropyl, chloropropyl, mercaptopropyl, polysulfide, isocyanatopropyl; m is a hydrocarbyloxy group of carbon atoms 1 to 18 or a halogen atom, a is 0, 1, 2 or 3, b is 0, 1, 2 or 3, a + b is 1, 2 or 3; the disilazane is (R)₉R₁₀R₁₁)SiNHSi(R₁₂R₁₃R₁₄)，R₉，R₁₀，R₁₁，R₁₂，R₁₃，R₁₄Is an independently selected hydrocarbon group of carbon atoms 1 to 18 or a hydrogen atom.
The method of claim 1, wherein the method comprises removing coarse particles of 1, 3, 5, 10, 20, 45, 55, or 75 microns or more from the spherical or angular powder filler using dry or wet sieving or inertial classification.
Spherical or angular powder filler obtained by the preparation method according to any of claims 1 to 5, characterized in that the particle size of the spherical or angular powder filler is 0.1 to 50 μm.
The use of spherical or angular powder filler according to claim 6, wherein spherical or angular powder fillers of different particle size are tightly packed in a graded manner in a resin to form a composite material.
The use according to claim 7, wherein the composite material is suitable for semiconductor packaging materials, circuit boards and intermediate semi-finished products thereof, prepregs or copper-clad plates of high-frequency and high-speed circuit boards.