WO2023191231A1 - Heat dissipation sheet having high thermal conductivity and high tensile strength, and production method for same - Google Patents

Abstract

The present invention relates to a heat dissipation sheet having high thermal conductivity and high tensile strength, and a production method for same, and more specifically relates to a heat dissipation sheet having high thermal conductivity and high tensile strength in which the size and amount of inorganic particles included have been adjusted to a specific range, thus the heat dissipation sheet has high thermal conductivity and excellent tensile strength, and a production method for same.

Description

High thermal conductivity heat dissipation sheet with high tensile strength and manufacturing method thereof

The present invention relates to a high thermal conductivity heat dissipation sheet having high tensile strength and a method of manufacturing the same. More specifically, the heat dissipation sheet has high thermal conductivity and excellent tensile strength by controlling the size and content of inorganic particles to a specific range. It relates to a high thermal conductivity heat dissipation sheet having a and a method of manufacturing the same.

In a semiconductor manufacturing process, in order to perform plasma processing on a semiconductor wafer, a plasma processing device having a loading table for installing the wafer inside a vacuum chamber is used. Recently, the diameter of semiconductor wafers has become larger and the processing precision has been refined, and in order to uniformly perform plasma processing on the wafer, it is necessary to apply a uniform temperature distribution. Therefore, a heater is installed on the outer periphery of the loading table, and a focus ring is installed on it through a heat conductive sheet to heat it.

Recently, in order to efficiently dissipate heat by transferring heat generated from semiconductor modules such as power semiconductors to a heat sink, a technology has been developed to install a thermally conductive sheet that reduces contact thermal resistance between the semiconductor module and the heat sink.

Meanwhile, due to the miniaturization and high power of electrical and electronic products, power consumption has increased significantly, and the heat dissipation problem of the accompanying components has become an issue.

In order to improve this heat dissipation problem, a heat dissipation sheet with excellent heat dissipation properties has been developed in which a resin composition containing polyorganosiloxane and an inorganic filler is cured on the member. However, in order to increase the thermal conductivity of the heat dissipation sheet, the amount of inorganic filler charged is As the concentration increases above 80 vol%, the tensile strength of the heat dissipation sheet decreases, causing problems with workability when using the heat dissipation sheet. Therefore, there is a need for research and development on heat dissipation sheets that have high thermal conductivity properties and high tensile properties.

In order to solve the above problems, the present invention implements a thermal conductivity of 10 W/mK or more and provides workability and adhesion for mechanical processing such as punching, trimming, and routing work for applying heat dissipation sheets to components and modules. The purpose is to provide a high thermal conductivity heat dissipation sheet that allows for ease of attachment/detachment work and rework after use, and has a high tensile strength that improves the tensile strength of the heat dissipation sheet by 0.2 MPa to 1.0 MPa, and a method of manufacturing the same.

The high thermal conductivity heat dissipation sheet having high tensile strength according to an embodiment of the present invention includes AlN particles having a particle size of 40㎛ to 100㎛, Al ₂ O ₃ particles having a particle size of 2㎛ to 10㎛, and 0.1㎛ to 1㎛. It contains Al ₂ O ₃ particles with a particle size of .

800 to 1,100 parts by weight of AlN particles having a particle size of 40 ㎛ to 100 ㎛, 450 to 550 parts by weight of Al ₂ O ₃ particles having a particle size of 2 ㎛ to 10 ㎛, and 0.1 ㎛ to 1 ㎛ It contains 200 to 350 parts by weight of Al ₂ O ₃ particles having a particle size of .

In addition, the component amount of AlN particles having a particle size of _40㎛ to _100㎛ is If the component amount of Al ₂ O ₃ particles having is defined as Z parts by weight, the following relational equation (1) is satisfied.

0.4 ≤ Y/X ≤ 0.7 (Relation 1)

In addition, the component amount of AlN particles having a particle size of _40㎛ to _100㎛ is If the component amount of Al ₂ O ₃ particles having is defined as Z parts by weight, the following relational equation (2) is satisfied.

0.2 ≤ Z/X ≤ 0.4 (Relation 2)

The heat dissipation sheet has high tensile strength, characterized by a thermal conductivity of 10 W/mK or more.

The heat dissipation sheet having a tensile strength of 0.2 MPa or more is used.

Use the heat dissipation sheet with a tear strength of 0.03 kgf/cm or more.

The heat dissipation sheet is used that does not tear during press processing.

A method of manufacturing a high thermal conductivity heat dissipation sheet with high tensile strength, which is an embodiment of the present invention, includes a first step of premixing AlN particles, inorganic particles containing Al ₂ O ₃ particles, a polymer binder, a surface treatment agent, and a catalyst; a second step of mixing with the polymer matrix; It includes a third step of manufacturing a thermally conductive sheet.

The inorganic particles contain AlN particles with a particle size of 40 μm to 100 μm, Al ₂ O ₃ particles with a particle size of 2 μm to 10 μm, and Al ₂ O ₃ particles with a particle size of 0.1 μm to 1 μm. .

The inorganic particles are used in an amount of 1500 to 1800 parts by weight, the polymer binder is used in an amount of 50 to 100 parts by weight, the catalyst is used in an amount of 0.1 to 3 parts by weight, and the surface treatment agent is used in an amount of 1 to 10 parts by weight.

According to the high thermal conductive heat dissipation sheet having high tensile strength and the manufacturing method thereof of the present invention, the use of aluminum nitride compound and aluminum oxide as specific components of the inorganic pillar has the effect of having high thermal conductivity, high tensile strength, and high tear strength. Furthermore, it has the effect of having workability for mechanical processing, ease of work when attaching and detaching to an adherend, and reworkability after use of the heat conductive sheet.

The embodiments described below are merely illustrative, and various modifications are possible from these embodiments. Hereinafter, terms are used solely for the purpose of distinguishing one component from another. Singular expressions include plural expressions unless the context clearly dictates otherwise. Additionally, when a part is said to "include" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

The method for manufacturing a high thermal conductivity heat dissipation sheet with high tensile strength of the present invention is to premix a mixture containing an inorganic filler, a polymer binder, a surface treatment agent, and a catalyst, mix the premixed mixture with a polymer matrix, and then heat conductivity. It includes manufacturing a sheet.

The inorganic filler used in the high thermal conductivity heat dissipation sheet of the present invention preferably contains AlN particles and Al ₂ O ₃ particles and has high tensile strength and high tear strength while maintaining high thermal conductivity.

Tensile strength is a parameter that indicates the degree to which the high thermal conductivity heat dissipation sheet can withstand without breaking when pulled from both sides, and tear strength is the force required to tear the high thermal conductivity heat dissipation sheet. It can be used to measure the performance of the seat.

It is an important factor in determining the mechanical properties such as tensile strength and tear strength of a high thermal conductivity heat dissipation sheet, and is affected by the type and content of the polymer matrix constituting the heat dissipation sheet, the type and content of the inorganic filler, and the surface treatment agent for the inorganic filler. In addition, as another important factor that determines the mechanical properties of the high thermal conductivity heat dissipation sheet, it may also depend on the heat dissipation sheet processing method. For example, a method of coating a surface treatment agent on an inorganic filler such as a wet method, a dry method, or an integral blend method, a method of mixing a surface-treated inorganic filler into a polymer matrix such as a continuous polymerization process or a batch polymerization process, and a thermally conductive sheet composition. The mechanical properties of the high thermal conductivity heat dissipation sheet may vary depending on various process conditions, such as coating and curing methods on the substrate.

In the present invention, specific parameters of the AlN particles and Al ₂ O ₃ particles of i) to iii) that can satisfy the tensile strength and tear strength in a high thermal conductivity heat dissipation sheet are defined.

i) AlN particle size 40㎛ to 100㎛

ii) Al ₂ O ₃ particle size 2㎛ to 10㎛

iii) Al ₂ O ₃ particle size 0.1㎛ to 1㎛

Here, it is preferable that the AlN particles under condition i) have a size of 40㎛ to 100㎛ and contain 800 to 1100 parts by weight. In addition, it is more preferable that the AlN particles have a size of 40㎛ to 100㎛ and contain 900 to 1100 parts by weight in terms of thermal conductivity and tensile strength.

In addition, condition ii), the content of Al ₂ O ₃ particles with a size of 2 ㎛ to 10 ㎛ is preferably 450 to 550 parts by weight, and the content of Al ₂ O ₃ particles with a size of 2 ㎛ to 10 ㎛ is preferably 450 parts by weight. It is more preferable to contain from 500 parts by weight to 500 parts by weight.

In addition, condition iii), it is preferable that the Al ₂ O ₃ particles with a size of 0.1 ㎛ to 1 ㎛ contain 200 to 350 parts by weight, and the Al ₂ O ₃ particles with a size of 0.1 ㎛ to 1 ㎛ contain 200 parts by weight. Containing from 300 parts by weight to 300 parts by weight is good in terms of thermal conductivity and tensile strength.

On the other hand, the thermally conductive _sheet of the present invention _is composed of Defined as Z parts by weight of Al ₂ O ₃ particles having a particle size of , it is preferable to satisfy the following relational equation (1).

0.4 ≤ Y/X ≤ 0.7 (Relation 1)

In addition, the thermally conductive sheet of the present invention _{is composed} of Defined as Al ₂ O ₃ particles having a particle size of Z parts by weight, it is preferable to satisfy the following relational equation (2).

0.2 ≤ Z/X ≤ 0.4 (Relation 2)

If the above relations 1 and 2 are satisfied, tearing during press processing of the heat dissipation sheet can be prevented.

By using the inorganic filler of the present invention, the thermal conductivity of the heat dissipation sheet can be obtained at least 10 W/mK, more preferably at least 14 W/mK, and most preferably at least 20 W/mK. You can.

In addition, by using this inorganic filler, the tensile strength of the heat dissipation sheet can be obtained at 0.2 MPa or more and 1.0 MPa or less, more preferably 0.3 MPa or more, and most preferably 0.5 MPa or more. If the tensile strength is less than the above range, there is a problem with workability, and if it exceeds the above range, the hardness or thermal resistance of the heat dissipation sheet is reduced.

Particles with a small diameter of the inorganic filler are filled between the large-diameter inorganic filler particles of the present invention, and the filling can be performed in a state close to close packing, thereby achieving high thermal conductivity. Therefore, when the inorganic filler is used, the mixture has high thermal conductivity, excellent electrical insulation, and is suitable for use as a raw material for a thermally conductive composition sheet. The shape of the inorganic filler can be spherical, flat, polyhedral, etc. there is. The inorganic filler of the present invention can be used in an amount of 80 vol% or more, more preferably 85 vol% or more, and most preferably 90 vol% or more, with respect to the thermal conductive composition sheet, to obtain a highly filled, high thermal conductive sheet.

The method for manufacturing a highly thermally conductive heat dissipation sheet of the present invention includes a first step of premixing AlN particles, inorganic particles containing Al ₂ O ₃ particles, a polymer binder, a surface treatment agent, and a catalyst; a second step of mixing with the polymer matrix; A third step of manufacturing a thermally conductive sheet may be included.

The surface treatment agent is preferably a silane compound or a partial hydrolyzate thereof. Examples of silane compounds include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, and octyltrimethoxysilane. Limethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, It may include one type or a mixture of two or more types selected from octadecyltrimethoxysilane and octadecyltriethoxysilane. Treating the surface of an inorganic filler by surface treatment includes physical adsorption in addition to chemical bonding such as covalent bonding.

In the first step, premixing may be performed by further including a solvent. Here, the solvent is water, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylenephosphonium triamide, acetonitrile, benzonitrile, etc. Polar solvents represented by; Phenols represented by cresol, phenol, xylenol, etc.; Alcohols represented by methanol, ethanol, propanol, butanol, etc.; Ketones represented by acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.; Acetic acid Esters represented by ethyl, propyl acetate, butyl acetate, etc.; Hydrocarbons represented by hexane, heptane, benzene, toluene, xylene, etc.; Carboxylic acids represented by formic acid, acetic acid, etc.; Carbonates represented by ethylene carbonate, propylene carbonate, etc. Compounds; Ether compounds represented by dioxane, diethyl ether, etc.; Chain ethers represented by ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, etc.; 3-methyl Heterocyclic compounds represented by -2-oxazolidinone, etc.; Nitrile compounds represented by acetonitrile, glutarodinitrile, methoxyacetonitrile, propionitrile, benzonitrile, etc. can be suitably exemplified. In view of the surface treatment agent being easily coated on the surface of the inorganic filler, the type of solvent can be appropriately mixed and used. If a solvent with a low boiling point is used, the process temperature can be lowered during compounding in the post-process, and the process time can be reduced. can be shortened to increase productivity.

The catalyst is intended to promote curing during high temperature and vacuum compounding. Examples of catalysts include platinum black, chloroplatinic acid, chloroplatinic acid, a reaction product of chloroplatinic acid and a monohydric alcohol, and a complex of chloroplatinic acid and olefins or vinylsiloxane. , platinum-based catalysts such as platinum biacetoacetate, palladium-based catalysts, and rhodium-based catalysts can be used. The content of the catalyst may be any amount necessary for curing, and can be adjusted appropriately depending on the desired curing speed, etc.

In the premixed mixture, the surface of the inorganic filler can be treated using a dry method, an integral blend method, or a semi-wet method, and after surface treatment of the inorganic filler, mixing with the polymer matrix is a continuous polymerization process (continuous compounding). It can be carried out by a polymerization process, and it can be carried out by a batch polymerization process, which is batch compounding.

The polymer matrix may contain silicone polymer. As an example of a silicone polymer, organopolysiloxane containing a silicon atom bonded to an alkenyl group can be used. Additionally, an organopolysiloxane having 2 to 8 carbon atoms, such as a vinyl group or an allyl group, may be used in combination with the silicone polymer. The molecular structure of the silicone polymer may be linear, cyclic, branched, or three-dimensional network, and the viscosity of the polymer matrix mixture can be adjusted by appropriately selecting the substituents or molecular structure. Here, the polymer matrix can be used as a mixture of an inorganic filler and an adhesive polymer to strengthen the bond between the polymer matrix, if necessary.

Describing the process of manufacturing the thermally conductive sheet of the present invention, it can be obtained by coating a mixture from which the remaining solvent has been removed on a support, curing it through drying and heat treatment, and then peeling the cured material on the support. The support can be a polyethylene terephthalate (PET) film, polyphenylene sulfide film, polyimide film, etc., and if necessary, the surface of the support is subjected to surface treatment with silicone, silane coupling agent, aluminum chelating agent, etc. The adhesion and peelability of the thermally conductive sheet and the support can be improved. In addition, methods of applying the mixture from which the residual solvent has been removed on the support include rotational application using a spinner, spray application, roll coating, screen printing, blade coater, die coater, calendar coater, meniscus coater, bar coater, and roll coater. , comma roll coater, gravure coater, screen coater, slit die coater, etc. can be appropriately selected considering application thickness and productivity. For drying and curing after application, ovens, hot plates, infrared rays, etc. can be used.

(Example)

As shown in Table 1 below, in Examples 1 to 4, vinyl polydimethylsiloxane (PDMS) (A) and hydrogen polydimethylsiloxane (B) were used as the polymer binder, a platinum catalyst was used as the catalyst, and as a surface treatment agent. Methyltrimethoxysilane (MTMS) was used. Then, the inorganic filler was mixed with AlN granule 80㎛, AlN granule 50㎛, Al ₂ O ₃ granule 5㎛, Al ₂ O ₃ granule 3㎛, and Al ₂ O ₃ granule 0.5㎛ in the ratio shown in Table 1 to make a thermally conductive sheet. Manufactured. Thermal conductivity and tensile strength were measured, and workability was judged. Here, the component ratio represents parts by weight (g).

As parameters for expressing _{the physical} properties of the thermally conductive sheet of the present invention, It was defined as the Z weight part of Al ₂ O ₃ particles having a particle size of 0.1㎛ to 1㎛.

	ingredient	Example 1	Example 2	Example 3	Example 4	Comparative Example 1	Comparative example 2	Comparative Example 3			Comparative Example 4
polymer bookbinder	silicone polymer (A)	50	50	50	50	50	50	50			50
	silicon polymer (B)	50	50	50	50	50	50	50			50
catalyst	Platinum catalyst (g)	0.5	0.5	0.5	0.5	0.5	0.5	0.5			0.5
surface treatment agent	Silane (g)	5	5	5	5	5	5	5			5
weapon filler	AIN filler 80㎛	980	500	980	600	750	1230	620			600
	AIN filler 50㎛		480		380			610			600
	Al 2 O 3 filler 5㎛	450	450			600	400	400			350
	Al 2 O 3 filler 3㎛			550	440
	Al 2 O 3 filler 0.5㎛	300	300	200	310	380	100	100			180
	Y/X	0.46	0.46	0.56	0.45	0.80	0.33	0.33			0.29
	Z/X	0.31	0.31	0.20	0.32	0.51	0.08	0.08			0.15
thermal conductivity	W/mK	14.1	12.5	13.2	12.4	9.5	9.2	8.5			8.3
Seal robbery	MPa	0.35	0.32	0.3	0.31	0.12	0.09	0.11			0.10
tear robbery	kgf/cm	0.11	0.09	0.12	0.12	0.02	0.02	0.02			0.01
Workability	During press processing tearing (PASS/NG)	PASS	PASS	PASS	PASS	NG	NG	NG			NG

As shown in Table 1, in Examples 1 to 4, AlN and Al ₂ O ₃ had excellent thermal conductivity, tensile strength, and tear strength within the above range, and did not have tearing properties during press processing. In particular, it was confirmed that Example 1 showed the best effect. However, in Comparative Examples 1 to 4, it was confirmed that the thermal conductivity was low and the tensile strength and tear strength were also low, resulting in tearing properties during press processing.

Additionally, in order to confirm the effect of the surface treatment agent, as shown in Table 2 below, a surface treatment agent was used in Examples 1 and 2, and no surface treatment agent was used in Comparative Examples 5 and 6. Here, the component ratio represents parts by weight (g).

	ingredient	Example 1	Example 2	Comparative Example 1		Comparative example 2
polymer bookbinder	Silicone polymer (A)	50	50	52.5		52.5
	silicon Polymer (B)	50	50	52.5		52.5
catalyst	Platinum catalyst (g)	0.5	0.5	0.5		0.5
surface treatment agent	Silane (g)	5	5	0		0
weapon filler	AIN filler 80㎛	980	500	980		500
	AIN filler 50㎛		480			480
	Al 2 O 3 filler 5㎛	450	450	450		450
	Al 2 O 3 filler 3㎛
	Al 2 O 3 filler 0.5㎛	300	300	300		300
thermal conductivity	W/mK	14.1	12.5	7.2		6.5
tensile strength	MPa	0.35	0.32	0.05		0.03
Tear strength	kgf/cm	0.11	0.09	0.01		0.01
Workability	Press When processing tearing (PASS/NG)	PASS	PASS	NG		NG

As shown in Table 2, Examples 1 and 2 had excellent thermal conductivity, tensile strength, and tear strength, and did not tear during press processing. However, in Comparative Examples 5 and 6, it was confirmed that the thermal conductivity was low and the tensile strength and tear strength were also low, resulting in tearing properties during press processing.

The thermal conductivity of the present invention was measured using Siemens Mentor Graphics DynTIM S (ASTM D5470), the tensile strength was measured using Instron 3367 (ASTM D412), and the tear strength was measured using Instron 3367 (ASTM D1004).

The present invention is not limited to the above-mentioned embodiments, but can be manufactured in various different forms, and those skilled in the art will be able to form other specific forms without changing the technical idea or essential features of the present invention. You will be able to understand that this can be implemented. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

Claims (11)

1. High tensile strength containing AlN particles with a particle size of 40 μm to 100 μm, Al ₂ O ₃ particles with a particle size of 2 μm to 10 μm, and Al ₂ O ₃ particles with a particle size of 0.1 μm to 1 μm. A heat dissipation sheet with high thermal conductivity.
2. In claim 1,

   800 to 1,100 parts by weight of AlN particles having a particle size of 40 ㎛ to 100 ㎛, 450 to 550 parts by weight of Al ₂ O ₃ particles having a particle size of 2 ㎛ to 10 ㎛, and 0.1 ㎛ to 1 ㎛ A high thermal conductivity heat dissipation sheet with high tensile strength, characterized in that it contains 200 to 350 parts by weight of Al ₂ O ₃ particles having a particle size of .
3. In claim 1,

   The component amount of AlN particles having a particle size of 40㎛ to 100㎛ is X parts by weight, the component amount of _Al2O3 particles _having a particle size of 2㎛ to 10㎛ is Y parts by weight, If the component amount of Al ₂ O ₃ particles is defined as Z parts by weight, a high thermal conductive heat dissipation sheet with high tensile strength, characterized in that it satisfies the following relational equation (1).

   0.4 ≤ Y/X ≤ 0.7 (Relation 1)
4. In claim 1,

   The component amount of AlN particles having a particle size of 40㎛ to 100㎛ is X parts by weight, the component amount of _Al2O3 particles _having a particle size of 2㎛ to 10㎛ is Y parts by weight, If the component amount of Al ₂ O ₃ particles is defined as Z parts by weight, a high thermal conductive heat dissipation sheet with high tensile strength, characterized in that it satisfies the following relational equation (2).

   0.2 ≤ Z/X ≤ 0.4 (Relation 2)
5. The method of any one of claims 1 to 4,

   A high thermal conductivity heat dissipation sheet with high tensile strength, characterized in that the heat dissipation sheet has a thermal conductivity of 10 W/mK or more.
6. The method of any one of claims 1 to 4,

   A high thermal conductivity heat dissipation sheet with high tensile strength, characterized in that the tensile strength of the heat dissipation sheet is 0.2 MPa or more.
7. The method of any one of claims 1 to 4,

   A high thermal conductivity heat dissipation sheet with high tensile strength, characterized in that the tear strength of the heat dissipation sheet is 0.03 kgf/cm or more.
8. The method of any one of claims 1 to 4,

   A high thermal conductivity heat dissipation sheet with high tensile strength, characterized in that the heat dissipation sheet does not tear during press processing.
9. A first step of premixing AlN particles, inorganic particles containing Al ₂ O ₃ particles, a polymer binder, a surface treatment agent, and a catalyst;

   a second step of mixing with the polymer matrix;

   A method of manufacturing a highly thermally conductive heat dissipation sheet comprising a third step of manufacturing a thermally conductive sheet.
10. In claim 9,

    The inorganic particles contain AlN particles having a particle size of 40 μm to 100 μm, Al ₂ O ₃ particles having a particle size of 2 μm to 10 μm, and Al ₂ O ₃ particles having a particle size of 0.1 μm to 1 μm. A method of manufacturing a high thermal conductivity heat dissipation sheet, characterized in that.
11. In claim 10,

    A method of manufacturing a highly thermally conductive heat dissipation sheet, characterized in that 1500 to 1800 parts by weight of the inorganic particles, 50 to 100 parts by weight of the polymer binder, 0.1 to 3 parts by weight of the catalyst, and 1 to 10 parts by weight of the surface treatment agent are used.