阅读说明：本技术 一种改性无机填料的制备方法、改性无机填料及导热凝胶 (Preparation method of modified inorganic filler, modified inorganic filler and heat-conducting gel ) 是由 曾小亮 马强强 李俊鸿 梁挺 庞云嵩 孙蓉 许建斌 于 2021-07-29 设计创作，主要内容包括：本申请提供的改性无机填料的制备方法,将导热粉体及所述硅烷水解液混合搅拌至混合溶液从浑浊变为澄清,将上述澄清液升温至40～60℃,恒温搅拌1-3小时,得到第一溶液,将所述第一溶液升温至115～125℃,并于真空环境中,恒温搅拌1-3小时,得到第二溶液,将所述第二溶液冷却至室温,得到所述改性无机填料,本申请提供的改性无机填料的制备方法,经过特殊硅烷的改性,在导热粉体表面接枝上兼容性良好的长链官能团,具有更优秀的亲油疏水性能,与树脂基体结合更紧密,改善了材料的柔韧性。另外,本申请还提供了改性无机填料及导热凝胶。(According to the preparation method of the modified inorganic filler, the heat-conducting powder and the silane hydrolysate are mixed and stirred until the mixed solution is changed from turbid to clear, the clear solution is heated to 40-60 ℃, the constant-temperature stirring is carried out for 1-3 hours, a first solution is obtained, the first solution is heated to 115-125 ℃, the constant-temperature stirring is carried out for 1-3 hours in a vacuum environment, a second solution is obtained, the second solution is cooled to room temperature, and the modified inorganic filler is obtained. In addition, the application also provides a modified inorganic filler and a heat-conducting gel.)

1. A preparation method of a modified inorganic filler is characterized by comprising the following steps:

preparing silane hydrolysate;

mixing and stirring heat-conducting powder and the silane hydrolysate until the mixed solution is clear from turbid;

heating the clarified solution to 40-60 ℃, and stirring for 1-3 hours at constant temperature to obtain a first solution;

heating the first solution to 115-125 ℃, and stirring for 1-3 hours at constant temperature in a vacuum environment to obtain a second solution;

and cooling the second solution to room temperature to obtain the modified inorganic filler.

2. The method for preparing a modified inorganic filler according to claim 1, wherein the step of preparing the silane hydrolysate comprises the steps of:

the silane coupling agent, deionized pure water and an alcohol solvent are mixed according to the mass fraction (0.3-0.5%): (0.3-0.5%): (0.5-4.0%) to obtain silane hydrolysate.

3. The method of claim 2, wherein the silane coupling agent is at least one selected from the group consisting of octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane.

4. The method for producing a modified inorganic filler according to claim 2, wherein the alcohol solvent is an anhydrous methanol or ethanol solvent.

5. The method according to claim 1, wherein the heat conductive powder is 160 times the mass of the silane hydrolysate in the step of mixing and stirring the heat conductive powder and the silane hydrolysate until the mixed solution changes from turbid to clear.

6. The method of claim 1, wherein the thermally conductive powder is at least one selected from the group consisting of highly pure spherical aluminum powder, highly pure spherical aluminum oxide, highly pure spheroidal aluminum nitride, and highly pure nano zinc oxide.

7. The method of claim 6, wherein the high purity spherical aluminum powder, the high purity spherical alumina, and the high purity spheroidal aluminum nitride have a D50 particle size of 0.5-15 μm.

8. A modified inorganic filler obtained by the method for producing a modified inorganic filler according to any one of claims 1 to 7.

9. A thermally conductive gel comprising the modified inorganic filler of claim 8.

Technical Field

The invention relates to the technical field of thermal interface materials, in particular to a preparation method of a modified inorganic filler, the modified inorganic filler and a heat-conducting gel.

Background

Thermal management of electronic devices is one of the key research directions in the field of electronic device manufacturing today. At present, electronic devices with highly integrated chip packaging technology are the development trend in the field, but due to the feature of high density, the chips and electronic equipment generate a large amount of heat during operation. The technical problem seriously influences the calculation speed of the chip, reduces the service efficiency of the electronic equipment and shortens the service life of the electronic equipment.

To solve the above problems, a heat sink is commonly used in the industry to connect with a chip to efficiently conduct heat generated during operation to an external region of a semiconductor package in real time, thereby ensuring efficient operation of an electronic device. However, the heat sink and the chip are hard-connected, which causes a large amount of gaps at the interface to influence heat transfer, so that the problem can be solved by filling the thermal interface material at the connection.

Thermal interface materials are currently mainly divided into three major classes: heat-conducting silicone grease, a heat-conducting gasket and heat-conducting gel. Although the heat-conducting silicone grease is used in a large area at present, the problems that the heat-conducting silicone grease is not suitable for large-area coating, is inconvenient to operate, is easy to age after being used at a high temperature for a long time, has volatility and the like exist; the heat-conducting gasket has the disadvantages that the manufacturing process of the over-thin gasket is complex, the cost is relatively high, and meanwhile, the large-scale automatic foot-padding operation cannot be carried out. Thermally conductive gels can circumvent the above problems compared to the first two, but there are still cases where the flexibility is lower.

Disclosure of Invention

In view of the above, it is necessary to provide a method for preparing a modified inorganic filler for modifying an inorganic filler inside a thermally conductive gel to improve gel performance.

In order to solve the above problems, the following technical solutions are adopted in the present application:

the application provides a preparation method of a modified inorganic filler, which comprises the following steps:

preparing silane hydrolysate;

mixing and stirring heat-conducting powder and the silane hydrolysate until the mixed solution is clear from turbid;

heating the clarified solution to 40-60 ℃, and stirring for 1-3 hours at constant temperature to obtain a first solution;

heating the first solution to 115-125 ℃, and stirring for 1-3 hours at constant temperature in a vacuum environment to obtain a second solution; and

and cooling the second solution to room temperature to obtain the modified inorganic filler.

In some embodiments, the step of preparing the silane hydrolysate specifically comprises the following steps:

the silane coupling agent, deionized pure water and an alcohol solvent are mixed according to the mass fraction (0.3-0.5%): (0.3-0.5%): (0.5-4.0%) to obtain silane hydrolysate.

In some of these embodiments, the silane coupling agent is selected from at least one of octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane.

In some of these embodiments, the alcoholic solvent is an anhydrous methanol or ethanol solvent.

In some embodiments, in the step of mixing and stirring the heat conductive powder and the silane hydrolysate until the mixed solution changes from turbid to clear, the heat conductive powder is 150-160 times of the quality of the silane hydrolysate.

In some embodiments, the thermally conductive powder is selected from at least one of high-purity spherical aluminum powder, high-purity spherical alumina, high-purity spheroidal aluminum nitride, and high-purity nano zinc oxide.

In some of the embodiments, the D50 particle size of the high-purity spherical aluminum powder, the high-purity spherical aluminum oxide and the high-purity spheroidal aluminum nitride is 0.5-15 μm.

In addition, the application also provides a modified inorganic filler prepared by the preparation method of the modified inorganic filler.

In addition, the application also provides a heat-conducting gel which comprises the modified inorganic filler.

By adopting the technical scheme, the invention has the following technical effects:

according to the preparation method of the modified inorganic filler, the heat-conducting powder and the silane hydrolysate are mixed and stirred until the mixed solution is changed from turbid to clear, the clear solution is heated to 40-60 ℃, the constant-temperature stirring is carried out for 1-3 hours, a first solution is obtained, the first solution is heated to 115-125 ℃, the constant-temperature stirring is carried out for 1-3 hours in a vacuum environment, a second solution is obtained, the second solution is cooled to room temperature, and the modified inorganic filler is obtained.

In addition, the modified inorganic filler prepared by the method can be used for preparing the heat-conducting gel, the prepared heat-conducting gel has high heat-conducting property, high elongation, low modulus, low bonding layer thickness and low thermal resistance, and excellent wetting property, can meet the severe requirements of chip packaging process flows and technologies, has high application reliability, can provide a proper, stable and healthy working temperature environment for chips, and improves the service life and efficiency of the chips.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention or in the description of the prior art will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a flow chart illustrating the steps of a method for preparing a modified inorganic filler according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "horizontal", "inside", "outside", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

Referring to fig. 1, a flow chart of steps of a method for preparing a modified inorganic filler according to an embodiment of the present invention includes the following steps:

step S110: preparing silane hydrolysate.

In some embodiments, the step of preparing the silane hydrolysate specifically comprises the following steps:

the silane coupling agent, deionized pure water and an alcohol solvent are mixed according to the mass fraction (0.3-0.5%): (0.3-0.5%): (0.5-4.0%) to obtain silane hydrolysate.

In some of these embodiments, the silane coupling agent is selected from at least one of octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, hexadecyltrimethoxysilane, octadecyltrimethoxysilane.

In some of these embodiments, the alcoholic solvent is an anhydrous methanol or ethanol solvent.

Step S120: and mixing and stirring the heat-conducting powder and the silane hydrolysate until the mixed solution is changed from turbid to clear.

In some embodiments, in the step of mixing and stirring the heat conductive powder and the silane hydrolysate until the mixed solution changes from turbid to clear, the heat conductive powder is 150-160 times of the quality of the silane hydrolysate.

In some embodiments, the thermally conductive powder is selected from at least one of high-purity spherical aluminum powder, high-purity spherical alumina, high-purity spheroidal aluminum nitride, and high-purity nano zinc oxide.

In some of the embodiments, the D50 particle size of the high-purity spherical aluminum powder, the high-purity spherical aluminum oxide and the high-purity spheroidal aluminum nitride is 0.5-15 μm.

Step S130: and heating the clarified solution to 40-60 ℃, and stirring at a constant temperature for 1-3 hours to fully hydrolyze the silane coupling agent to obtain a first solution.

Step S140: and heating the first solution to 115-125 ℃, stirring for 1-3 hours at a constant temperature in a vacuum environment, and removing redundant deionized water and alcohol solvents to obtain a second solution.

Step S150: and cooling the second solution to room temperature to obtain the modified inorganic filler.

According to the preparation method of the modified inorganic filler, through modification of special silane, a long-chain functional group with good compatibility is grafted on the surface of the heat-conducting powder, so that the modified inorganic filler has more excellent oleophylic and hydrophobic properties, is more tightly combined with a resin matrix, and improves the flexibility of the material.

In addition, the modified inorganic filler prepared by the method can be used for preparing the heat-conducting gel, the prepared heat-conducting gel has high heat-conducting property, high elongation, low modulus, low bonding layer thickness and low thermal resistance, and excellent wetting property, can meet the severe requirements of chip packaging process flows and technologies, has high application reliability, can provide a proper, stable and healthy working temperature environment for chips, and improves the service life and efficiency of the chips.

The above technical solution of the present invention will be described in detail with reference to the following examples.

Example 1

(1) Preparing silane coupling agent hydrolysate required by powder modification:

the octyl trimethoxy silane coupling agent, deionized water and anhydrous methanol are uniformly mixed and stirred at the mass ratio of 1:1:3 at the normal temperature at the speed of 200 r/min for about 90 minutes, and the mixed solution can be used after being changed from turbid to clear.

(2) Preparing modified filler powder:

adding a certain amount of high-purity spherical aluminum powder into a planetary machine for stirring, and dropwise adding the prepared coupling agent hydrolysate within 5 minutes, wherein the dosage of the coupling agent hydrolysate is about 0.5 percent of the mass of the coupling agent. Heating to 50 ℃ in a planet machine, and continuously stirring for 1 hour after the temperature is stable; then heating to 120 ℃, opening the vacuum after the temperature is stable, and continuously stirring for 1 hour; finally, cooling to room temperature, taking out of the pot, sealing and packaging to obtain the modified powder.

Example 2

(1) Preparing silane coupling agent hydrolysate required by powder modification:

the decyl trimethoxy silane, the deionized water and the anhydrous methanol are uniformly mixed and stirred at the normal temperature at the speed of 200 revolutions per minute for about 60 minutes according to the mass ratio of 1:1:3, and the mixed solution is used after being changed from turbid to clear.

(2) Preparing modified filler powder:

adding a certain amount of high-purity spherical alumina into a planetary machine for stirring, and dropwise adding the prepared coupling agent hydrolysate within 5 minutes, wherein the dosage of the coupling agent hydrolysate is about 0.5 percent of the mass of the coupling agent. Heating to 50 ℃ in a planet machine, and continuously stirring for 1 hour after the temperature is stable; then heating to 120 ℃, opening the vacuum after the temperature is stable, and continuously stirring for 1 hour; finally, cooling to room temperature, taking out of the pot, sealing and packaging to obtain the modified powder.

Example 3

(1) Preparing silane coupling agent hydrolysate required by powder modification:

the dodecyl trimethoxy silane, the deionized water and the anhydrous methanol are uniformly mixed and stirred at the normal temperature at the speed of 200 revolutions per minute for about 30 minutes according to the mass ratio of 1:1:3, and the mixed solution is used after being changed from turbid to clear.

(2) Preparing modified filler powder:

adding a certain amount of high-purity spheroidal aluminum nitride into a planetary machine for stirring, and dropwise adding the prepared coupling agent hydrolysate within 5 minutes, wherein the dosage of the coupling agent hydrolysate is about 0.5 percent of the mass of the coupling agent. Heating to 50 ℃ in a planet machine, and continuously stirring for 1 hour after the temperature is stable; then heating to 120 ℃, opening the vacuum after the temperature is stable, and continuously stirring for 1 hour; finally, cooling to room temperature, taking out of the pot, sealing and packaging to obtain the modified powder.

Example 4

(1) Preparing silane coupling agent hydrolysate required by powder modification:

the hexadecyl trimethoxy silane, deionized water and absolute ethyl alcohol are uniformly mixed and stirred at the normal temperature at the speed of 200 revolutions per minute for about 180 minutes according to the mass ratio of 1:1:3, and the mixed solution is used after being changed from turbid to clear.

(2) Preparing modified filler powder:

adding a certain amount of high-purity nano zinc oxide into a planetary machine for stirring, and dropwise adding the prepared coupling agent hydrolysate within 5 minutes, wherein the dosage of the coupling agent hydrolysate is about 0.5 percent of the mass of the coupling agent per se. Heating to 50 ℃ in a planet machine, and continuously stirring for 1 hour after the temperature is stable; then heating to 120 ℃, opening the vacuum after the temperature is stable, and continuously stirring for 1 hour; finally, cooling to room temperature, taking out of the pot, sealing and packaging to obtain the modified powder.

The modified filler powder and the unmodified filler powder obtained in the above examples 1 to 4 are uniformly mixed with different types of silicone oil matrixes required for preparing the thermal interface material, so as to obtain the thermal interface material in different examples, wherein the mass of each component is as shown in the following table:

components	Mass, g
		Powder filler	900
Vinyl terminated polysiloxanes	8.392
		Terminal hydrogen-containing polysiloxane	1.232
Pendant hydrogenpolysiloxanes	0.360
		Inhibitors	0.003

The rheological property, the basic mechanical property, the basic thermal property and the reliability of the obtained thermal interface material are tested, and the test results are as follows:

from the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: the formula proportion of the invention is precisely matched and verified, the powder is selected from high-purity spherical heat-conducting powder with low particle size, long-chain functional groups with good compatibility are grafted on the surface of the powder by modification of special silane, the invention has more excellent oleophylic and hydrophobic properties, is more tightly combined with a resin matrix, improves the flexibility of materials, has high heat-conducting property, high elongation, low modulus, low bonding layer thickness and low thermal resistance, has excellent wetting property, can meet the severe requirements of chip packaging process flow and technology, has high application reliability, can provide a proper, stable and healthy working temperature environment for a chip, and improves the service life and efficiency of the chip.

The foregoing is considered as illustrative only of the preferred embodiments of the invention, and is presented merely for purposes of illustration and description of the principles of the invention and is not intended to limit the scope of the invention in any way. Any modifications, equivalents and improvements made within the spirit and principles of the invention and other embodiments of the invention without the creative effort of those skilled in the art are included in the protection scope of the invention based on the explanation here.