Method For Preparing Spherical Or Angular Powder Filler, Spherical Or Angular Powder Filler Obtained Therefrom, And Use Thereof

Abstract

The present invention relates to a method for preparing a spherical or angular powder filler, comprising providing a spherical or angular siloxane comprising T units; performing a heat treatment on the spherical or angular siloxane, the heat treatment temperature between 250° C. and the temperature of oxidative decomposition of organic groups, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain a condensed siloxane; and adding a treatment agent to treat the condensed siloxane to promote the condensation of silicon hydroxyl groups in the condensed siloxane to give a spherical or angular powder filler, the treatment agent comprising a silane coupling agent and/or disilazane, and the quotient of the molecular weight of at least a portion of the silane coupling agent and/or the disilazane divided by its specific gravity at 25° C. being less than or equal to 210. The present invention also provides a spherical or angular powder filler obtained therefrom. The present invention further provides use of above spherical or angular powder filler. The filler provided by the present invention has low permittivity, low permittivity loss, without conductive impurities, without coarse oversize particles, and low radioactivity.

Claims

1. A method for preparing a spherical or angular powder filler, comprising the steps of: S1, providing a spherical or angular siloxane comprising T units, wherein the T unit=R.sub.1SiO.sub.3—, and R.sub.1 is a hydrogen atom or an organic group independently selected from C.sub.1-C.sub.18; S2, performing a heat treatment on the spherical or angular siloxane, the heat treatment temperature between 250° C. and the temperature of oxidative decomposition of organic groups, so that silicon hydroxyl groups in the spherical or angular siloxane are condensed to obtain a condensed siloxane; and S3, adding a treatment agent to treat the condensed siloxane to promote the condensation of silicon hydroxyl groups in the condensed siloxane to give a spherical or angular powder filler, the treatment agent comprising a silane coupling agent and/or disilazane, the weight percentage of the treatment agent being 0.5-50 wt %, and the quotient of the molecular weight of at least a portion of the silane coupling agent and/or the disilazane divided by its specific gravity at 25° C. being less than or equal to 210.

2. The method according to claim 1, wherein the spherical or angular siloxane further comprises Q units, D units, and/or M units, wherein the Q unit=SiO.sub.4—, D unit=R.sub.2R.sub.3SiO.sub.2—, the M unit=R.sub.4R.sub.5R.sub.6SiO.sub.2—, and each of R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 is a hydrogen atom or a hydrocarbyl independently selected from C.sub.1-C.sub.18.

3. The method according to claim 1, wherein the spherical or angular siloxane further comprises silicon dioxide particles.

4. The method according to claim 1, wherein the heat treatment temperature of S2 is 250-320° C.

5. The method according to claim 1, wherein the silane coupling agent is at least one agent selected from silane coupling agent (R.sub.7).sub.a(R.sub.8).sub.bSi(M).sub.4-a-b, wherein R.sub.7, R.sub.8 each is a hydrogen atom, a hydrocarbyl independently selected from C.sub.1-C.sub.18, a hydrocarbyl independently selected from C.sub.1-C.sub.18 replaced by functional groups, wherein the functional group is at least one group selected from the group consisting of following organic functional groups: vinyl, allyl, styryl, epoxy group, aliphatic amino, aromatic amino, methacryloxypropyl, acryloxypropyl, ureidopropyl, chloropropyl, mercapto propyl, polysulfide, isocyanate propyl; and wherein is an alkoxy group of C.sub.1-C.sub.18 or a halogen atom, a=0, 1, 2 or 3, b=0, 1, 2 or 3, and a+b=1, 2 or 3.

6. The method according to claim 1, wherein the disilazane is at least one agent selected from disilazane (R.sub.9R.sub.10R.sub.11)SiNHSi(R.sub.11R.sub.12R.sub.13R.sub.14), and wherein R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13, R.sub.14 each is a hydrogen atom or a hydrocarbyl independently selected from C.sub.1-C.sub.18.

7. The method according to claim 1, wherein the method further comprises removing coarse oversize particles above 1, 3, 5, 10, 20, 45, 55, or 75 μm in the spherical or angular powder filler by dry or wet sieving or inertial classification.

8. The method according to claim 1, wherein the spherical or angular powder filler has a particle size of 0.1-50 μm, and wherein the volatile moisture content of the spherical or angular powder filler at 200° C. is less than or equal to 3000 ppm.

9. The method according to claim 8, wherein the spherical or angular powder filler is tightly packed in the resin to form a composite material.

10. The method according to claim 9, wherein the composite material is suitable for semiconductor packaging material, circuit board and intermediate semi-finished product.

11. (canceled)

Description

DESCRIPTION OF THE ENABLING EMBODIMENT

[0035] The preferred embodiments of the present invention are given below and described in detail.

[0036] The detection methods involved in the following embodiments include:

[0037] The average particle size is measured by a laser particle size distribution instrument HORIBA LA-700, and the solvent is isopropanol;

[0038] The specific surface area is measured by SHIMADZU FlowSorbIII2305;

[0039] The true specific gravity is measured by MicrotracBEL BELPycno;

[0040] The thermal expansion coefficient of the filler is calculated from the known thermal expansion coefficient and true specific gravity of epoxy resin, the true specific gravity of the filler, and the measured thermal expansion coefficient of a resin sample containing a certain amount of filler.

[0041] Uranium or thorium content is measured by Agilent 7700X ICP-MS. The sample is prepared by total dissolution in hydrofluoric acid after burning at 800° C.;

[0042] The volatile moisture content at 200° C. is measured by Mitsubishi Chemical CA-310 Karl Fischer automatic analyzer with heated vaporizer.

[0043] The content of Q, T, D, or M units is measured by solid .sup.28Si-NMR nuclear magnetic resonance spectrum of JEOL ECS-400 Nuclear magnetic resonance instrument, wherein the Q unit content is calculated from the peak integrated area between −80 ppm and −120 ppm; the T unit content is calculated from the peak integrated area between −30 ppm and −80 ppm; the D unit content is calculated from the peak integrated area between −10 ppm and −30 ppm; and the M unit content is calculated from the peak integrated area between +20 ppm and −10 ppm; referring to Separation and Purification Technology Volume 25, Issues 1-3, Oct. 1, 2001, Pages 391-397, .sup.29Si NMR and Si2p XPS correlation in polysiloxane membranes prepared by plasma enhanced chemical vapor deposition.

[0044] The permittivity or the permittivity loss is measured by KEYCOM permittivity and permittivity loss measuring device Model No. DPS18 in perturbation method and sample hole block-shaped cavity resonance method.

[0045] In this text, temperature degree refers to “degrees Celsius”, that is, ° C.

[0046] Referring to “Spherical Silicone Resin Micropowder”, Huang Wenrun, Organic Silicone Materials, 2007, 21 (5) 294-299, the spherical siloxane of different compositions in Examples and Comparative Examples is prepared for subsequent heat treatment.

[0047] Methyltrichlorosilane or methyltrimethoxysilane was added into water to provide a white precipitate. After being washed with deionized water, the precipitate was ground by a sand mill to a fine powder of 2 μm in Examples and Comparative Examples for subsequent heat treatment.

[0048] In addition, methyltrichlorosilane or methyltrimethoxysilane was mixed with silicon dioxide, and the mixture was added into water to provide a white precipitate. After being washed with deionized water, the precipitate was ground by a sand mill to a fine powder of 2 μm in Examples and Comparative Examples for subsequent heat treatment.

Example 1

[0049] The spherical siloxane of 100% T units (R.sub.1 is methyl) with a particle size of 2 μm was heat treated in an air atmosphere at different temperatures. The treated powder was mixed with 10% methyltrimethoxysilane (the molecular weight of the silane coupling agent is 136.22, its specific gravity at 25° C. is 0.955, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 142.6, which is less than 210), the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain samples of Examples and Comparative Examples. The analysis results of the samples are listed in Table 1.

TABLE-US-00001 TABLE 1 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 1 100 0 2.0 250 20 2900 2.9 0.002 12 Example 2 100 0 2.0 280 20 2000 2.7 0.001 10 Example 3 100 0 2.0 320 20 900 2.6 <0.001 8 Comparative 100 0 2.0 200 20 15000 3.9 0.01 17 Example 1 Comparative 100 0 2.0 450 20 2500 4.9 0.01 6 Example 2 Comparative 100 0 2.0 650 20 1000 5.1 0.01 6 Example 3

[0050] Obviously, the permittivity of each of the samples obtained according to Example 1-Example 3 is less than 3, and the permittivity loss each is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era. The heat treatment temperature of Comparative Example 1 is too low and the heat treatment temperature of Comparative Examples 2-3 is too high, wherein the permittivity each is above 3, and the permittivity loss each is above 0.005, failing to meet the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 2

[0051] The spherical siloxane of 97% T units (R.sub.1 is methyl) and 3% Q units with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 8% methyltrimethoxysilane and then mixed with 2% 3-methacryloxypropyltrimethoxysilane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain samples of Examples and Comparative Examples. The analysis results of the samples are listed in Table 2. The Comparative Example 4 differs from Example 4 without methyltrimethoxysilane, and the Comparative Example 5 differs from Example 4 only with 3-methacryloxypropyltrimethoxysilane (the molecular weight of the silane coupling agent is 248.35, its specific gravity at 25° C. is 1.045, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 237.7, which is above 210).

TABLE-US-00002 TABLE 2 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 4 97 3 2.0 280 20 1200 2.7 <0.001 9 Comparative 97 3 2.0 280 20 3500 3.3 0.009 9 Example 4 Comparative 97 3 2.0 280 20 3600 3.4 0.009 9 Example 5

[0052] Obviously, the permittivity of the sample obtained according to Example 4 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era. The Comparative Example 4 without silane coupling agent for condensing silicon hydroxyl groups and the Comparative Example 5 with silane coupling agent, the quotient of whose molecular weight divided by its specific gravity at 25° C. is above 210, for condensing silicon hydroxyl groups provide the samples with permittivity above 3 and permittivity loss above 0.005, failing to meet the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 3

[0053] The spherical siloxane of 97% T units (R.sub.1 is methyl) and 3% D units (R.sub.2, R.sub.3 each is methyl) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 10% hexamethyldisilazane (the molecular weight of the disilazane is 161.39, its specific gravity at 25° C. is 0.774, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 208.5, which is less than 210), the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example. The analysis results of the sample are listed in Table 3.

TABLE-US-00003 TABLE 3 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit D unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 5 97 3 2.0 280 20 800 2.7 <0.001 10

[0054] Obviously, the permittivity of the sample obtained according to Example 5 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 4

[0055] Methyltrimethoxysilane and silicon dioxide were mixed and then added into water to provide a white precipitate. After being washed with deionized water, the precipitate was ground by a sand mill to a fine powder of 2 μm.

[0056] The angular siloxane of 70% T units (R.sub.1 is methyl) and 30% silicon dioxide fine powder (gas phase white carbon black) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 10% dimethyldimethoxysilane (the molecular weight of the disilazane is 120.22, its specific gravity at 25° C. is 0.88, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 136.6, which is less than 210), the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example. The analysis results of the sample are listed in Table 4.

TABLE-US-00004 TABLE 4 Composition of Angular Siloxane Evaporated Thermal silicon Average Heat Water Permittivity Expansion T unit dioxide Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 6 70 30 2.0 280 20 900 2.9 <0.001 3

[0057] Obviously, the permittivity of the sample obtained according to Example 6 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 5

[0058] The spherical siloxane of 100% T units (R.sub.1 is methyl) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 8% vinyltrimethoxysilane (the molecular weight of the disilazane is 148.23, its specific gravity at 25° C. is 0.971, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 152.7, which is less than 210) and then mixed with 4% hexamethyldisilazane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example 7. The analysis results of the sample are listed in Table 5.

[0059] The spherical siloxane of 100% T units (R.sub.1 is methyl) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with the mixture of 8% phenyltrimethoxysilane (the molecular weight of the disilazane is 198.29, its specific gravity at 25° C. is 1.062, and the quotient of the molecular weight divided by its specific gravity at 25° C. is 186.7, which is less than 210) and 4% hexamethyldisilazane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example 8. The analysis results of the sample are listed in Table 5.

TABLE-US-00005 TABLE 5 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 7 100 0 2.0 280 20 1900 2.6 <0.001 9 Example 8 100 0 2.0 280 20 1800 2.8 <0.001 9

[0060] Obviously, the permittivity of each of samples obtained according to Example 7-Example 8 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 6

[0061] The spherical siloxane of 100% T units (R.sub.1 is vinyl) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 8% hexamethyldisilazane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example 9. The analysis results of the sample are listed in Table 6.

[0062] The spherical siloxane of 100% T units (R.sub.1 is methyl) with a particle size of 2 μm was heat treated in an air atmosphere. The treated powder was mixed with 4% phenyltrimethoxysilane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example 10. The analysis results of the sample are listed in Table 6.

TABLE-US-00006 TABLE 6 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 9 100 0 2.0 250 20 2500 2.6 <0.001 9 Example 10 100 0 2.0 300 20 1000 2.9 <0.001 9

[0063] Obviously, the permittivity of each of samples obtained according to Example 9-Example 10 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 7

[0064] The spherical siloxane of 100% T units (R.sub.1 is methyl) with different particle sizes was heat treated in an air atmosphere in different time. The treated powder was mixed with 8% methyltrimethoxysilane, the mixture was heated at 180° C. for 6 h to obtain samples of Examples. The analysis results of the sample are listed in Table 7.

TABLE-US-00007 TABLE 7 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 11 100 0 0.5 290 1 800 2.60 <0.001 10 Example 12 100 0 2.0 290 3 800 2.61 <0.001 10 Example 13 100 0 10 290 7 800 2.60 <0.001 9 Example 14 100 0 30 290 15 800 2.60 <0.001 9 Example 15 100 0 50 290 20 800 2.59 <0.001 8

[0065] Obviously, the permittivity of each of samples obtained according to Example 11-Example 15 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

Example 8

[0066] Methyltrichlorosilane was added into water to provide a white precipitate. After being washed with deionized water, the precipitate was ground by a sand mill to a fine powder of 2 μm, filtrated, dried and heat treated in a nitrogen atmosphere. The treated powder was mixed with 15% methyltrimethoxysilane, the mixture was heated at 180° C. for 6 h, and the powder was separated by cyclone to remove coarse oversize particles above 10 μm to obtain the sample of Example. The analysis results of the sample are listed in Table 8.

TABLE-US-00008 TABLE 8 Composition of Spherical Evaporated Thermal Siloxane Average Heat Water Permittivity Expansion T unit Q unit Particle Heat Treatment Treatment Volume at Permittivity Loss Coefficient wt % wt % Size μm Temperature ° C. Time h 200° C. ppm 500 MHz 500 MHz ppm Example 16 100 0 2.0 280 20 900 2.9 0.005 11

[0067] Obviously, the permittivity of the sample obtained according to Example 16 is less than 3, and the permittivity loss is less than 0.005, meeting the requirement of low permittivity (less signal delay) and low permittivity loss (less signal loss) of the filler in the 5G era.

[0068] It should be understood that samples of above Example 1-Example 16 can be vertex cut to remove coarse oversize particles. Specifically, coarse oversize particles above 1, 3, 5, 10, 20, 45, 55, or 75 μm in the spherical or angular powder filler can be removed by dry or wet sieving or inertial classification according to the size of the semiconductor chip. Further, Uranium or thorium content of samples of above Example 1-Example 16 is less than 0.5 ppb, wherein the samples were dissolved in hydrofluoric acid and measured by ICP-MS.

[0069] The foregoing description refers to preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Various changes can be made to the foregoing embodiments of the present invention. That is to say, all simple and equivalent changes and modifications made in accordance with the claims of the present invention and the content of the description fall into the protection scope of the patent of the present invention. What is not described in detail in the present invention is conventional technical content.