WO2024111717A1 - Composite sheet with excellent thermal and electrical conductivity having reduced thermal resistance due to hardness control of carbon-based coating layer - Google Patents

Abstract

The present invention relates to a thermally and electrically conductive composite sheet having reduced thermal resistance due to hardness control of a carbon-based coating layer, more specifically to a thermally and electrically conductive composite sheet having reduced thermal resistance due to hardness control of a conductive layer comprising a carbon-based compound and a polymer binder.

Description

Composite sheet with excellent thermal and electrical conductivity that reduces thermal resistance by controlling the hardness of the carbon-based coating layer

The present invention relates to a composite sheet with excellent thermal and electrical conductivity that reduces thermal resistance by controlling the hardness of a carbon-based coating layer. More specifically, it relates to a composite sheet that reduces thermal resistance by controlling the hardness of a conductive layer containing a carbon-based compound and a polymer binder. It relates to a composite sheet with excellent thermal and electrical conductivity that reduces .

Semiconductor manufacturing process equipment that uses plasma, such as vacuum deposition and dry etching, suffers from serious thermal problems and various electromagnetic waves due to high plasma density and driving power during process operation. (electro-magnetic) problems arise. Due to these thermal and electromagnetic problems, the process yield of silicon wafers is greatly affected, and in particular, solving thermal problems in the upper and lower electrode parts where high voltage is applied is a major challenge.

Meanwhile, as a means to solve the thermal problem of the electrode part of semiconductor processing equipment and the electromagnetic instability related to plasma, materials with high thermal and electrical conductivity are installed in the electrode part of the process equipment to enable rapid heat transfer and localized heat. We are using a method to solve concentration problems. In particular, since the thermal and electrical conductivity of the heat dissipating material used inside the electrode portion has a significant impact on the process yield, research is being conducted to develop a heat dissipating material with excellent thermal and electrical conductivity.

Conventionally, as a heat dissipation material for semiconductor processing equipment, a composite material coated on both sides with a conductive carbon material on a metal foil such as Al or Cu has been widely used. However, when continuously exposed to an extreme plasma environment, the metal foil and the conductivity become unstable. There is a problem with carbon material delamination. This acts as a factor affecting process yield as the semiconductor process time elapses, and attempts are being made to find a solution to solve this problem.

Therefore, there is a need for research and development on composite sheets that can be applied to plasma processing equipment in terms of heat dissipation and hardness.

The purpose of the present invention is to provide a composite sheet with excellent thermal and electrical conductivity that satisfies sufficient hardness and low thermal resistance by reducing thermal resistance through controlling the hardness of the carbon-based coating layer.

A composite sheet with excellent thermal conductivity and electrical conductivity, which is an embodiment of the present invention, includes a base material; A primer layer formed on at least one side of the substrate; and a conductive layer formed on the primer layer and including a carbon-based compound and a polymer binder, wherein Shore A hardness is in the range of 50 to 95 Shore A.

The polymer binder is characterized in that it contains a base material, a curing agent, and a filler.

The weight ratio of the base material and the curing agent is characterized in that it is 1:0.6 to 1.2.

The main agent is a compound containing a vinyl group, and the curing agent is a compound containing a hydrogen group, and crosslinking occurs when the vinyl group of the main agent reacts with the hydrogen group of the curing agent.

The weight ratio of the carbon-based compound and the polymer binder is characterized in that 1:0.2 to 30.

The carbon-based compound is characterized in that its maximum diameter is 0.01 to 100㎛.

The carbon-based compound is one or more selected from the group consisting of graphite, carbon nanotubes (CNT), graphene, graphene oxide, carbon fiber and fullerene, carbon, nanocarbon, and carbon black. It is characterized by including.

The polymer binder is characterized in that it is at least one selected from the group consisting of thermosetting silicone rubber compounds, one-component thermosetting silicone binders, two-component thermosetting silicone binders, acrylic resins, epoxy resins, urethane resins, and urea-based resins.

The conductive layer is characterized in that it has a thickness of 5 to 450㎛.

The conductive layer is characterized by an average density of 1.0 to 5.0 g/cc.

The conductive layer is characterized by a porosity of 5% or less.

The thermal resistance of the composite sheet is characterized in that it ranges from 0.8 to 1.3 K/W.

The ratio of (shore A hardness)/(thermal resistance) of the composite sheet is characterized in that it ranges from 50 to 90 (shore A)/(K/W).

According to the thermal and electrically conductive composite sheet of the present invention, the process yield can be reduced by reducing thermal resistance through controlling the hardness of the carbon-based coating layer by varying the ratio of the base material and the curing agent.

The present invention is capable of various modifications and may have various embodiments. The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

A composite sheet with excellent thermal conductivity and electrical conductivity, which is an embodiment of the present invention, includes a base material; A primer layer formed on at least one side of the substrate; and a conductive layer formed on the primer layer and including a carbon-based compound and a polymer binder.

The shore A hardness of the composite sheet of the present invention is preferably 50 to 95 shore A, more preferably 75 to 95 shore A, and most preferably 80 to 95 shore A. Additionally, the thermal resistance of the composite sheet is preferably 0.8 to 1.3 K/W, and more preferably 1.0 to 1.2 K/W. Additionally, the wear resistance of the composite sheet is preferably 2 to 3%, and preferably 2 to 2.7%. If it is less than the above range, the contact interface thermal resistance will be lowered, but workability such as surface staining and scratches will deteriorate during work, and if it is greater than the above range, the contact interface thermal resistance will increase and the thermal resistance will increase, which is not desirable. .

(Shore A hardness)/(thermal resistance) of the composite sheet can be used in the range of 50 to 90 (shore A)/(K/W). More preferably, (Shore A hardness)/(heat resistance) can be 58 to 86 (shore A)/(K/W), and most preferably 78 to 86 (shore A)/(K/W). . In the above range, heat resistance and workability characteristics without increased yield can be obtained.

In the composite sheet of one embodiment, a conductive layer is formed on the primer layer, and the conductive layer includes a carbon-based compound and a polymer binder. The carbon-based compound is a material that has thermal and electrical conductivity, and the polymer binder is a material that helps the bonding force between the carbon-based compounds or between the conductive layer and the primer layer.

The composite sheet has excellent thermal and electrical conductivity as it contains a carbon-based compound having thermal and electrical conductivity, so when the composite sheet is used as a heat dissipation material for various electrical and electronic processing equipment, including semiconductor processing equipment, it is possible to quickly It has the advantage of solving local heat concentration problems by enabling heat transfer and preventing electromagnetic instability such as charging by plasma.

The conductive layer includes a carbon-based compound and a polymer binder, and the weight ratio of the carbon-based compound and the polymer binder is preferably 1:0.2 to 30, more preferably 1:0.5 to 15, and most preferably 1:1 to 2. It can be. If the weight ratio of the carbon-based compound and the polymer binder is less than 1:0.2, the adhesion between the polymer binder and the primer layer may decrease, causing delamination, and the filler may form on the surface due to the binder's inability to hold the carbon-based compound. It may smear, and if it exceeds 1:30, the polymer binder content may be too high and thermal and electrical conductivity may be lowered.

The maximum particle diameter of the carbon-based compound is not particularly limited, but in order to prevent the thickness of the conductive layer from becoming too thick and to make the thickness of the conductive layer uniform, the maximum particle diameter of the carbon-based compound is preferably 0.01 to 0.01. 100㎛ can be used, more preferably 0.1 to 70㎛, and most preferably 0.5 to 50㎛.

Carbon-based compounds included in the conductive layer include carbon black, graphite, carbon nanotubes (CNT), graphene, graphene oxide, carbon fiber and fullerene, carbon, nanocarbon, and carbon black. It may include one or more selected from the group consisting of. By including such a carbon-based compound, the conductive layer can exhibit high conductivity characteristics not only in the vertical direction but also in the horizontal direction on one side of the conductive layer. Preferably, the carbon-based compound included in the conductive layer may include graphite. These individual particles of graphite may have a flake form, have a maximum diameter of 0.01 to 100 μm, and have a density of 1.5 to 3.0 g/cm3.

It is preferable to use a material with excellent conductivity and shock absorption properties as the polymer binder. Specific examples of materials that can be used as such polymer binders include one or more selected from the group consisting of thermosetting silicone rubber compounds, one-component thermosetting silicone binders, two-component thermosetting silicone binders, acrylic resins, epoxy resins, urethane resins, and urea resins. These materials can be used, but due to their excellent adhesive strength, there is no need to provide a separate adhesive layer, which simplifies work fixation and reduces the production cost of the final product.

The polymer binder is characterized in that it contains a base material, a curing agent, and a filler. Additionally, it may further contain additives such as adhesion agents, coupling agents, and pigments. The weight ratio of the base material and the curing agent of the present invention can be 1:0.6 to 1.2, and more preferably 1:0.9 to 1.2.

In one embodiment of the polymer binder of the present invention, the main agent is a compound containing a vinyl group, and the curing agent may be a compound containing a hydrogen group. Preferably, the compound represented by Formula 1 can be used as the main agent, and the compound represented by Formula 2 can be used as the curing agent.

(where n1 is an integer from 10 to 150)

(where n2 is an integer from 10 to 150)

From the viewpoint of heat resistance, it is preferable that the vinyl group of the above-mentioned subject and the hydrogen group of the curing agent react with heat or light to cause crosslinking and increase hardness. For example, the bonding reaction between the vinyl group of the compound represented by Formula 1 and the hydrogen group of the compound represented by Formula 2 can be represented by Formula 3.

(Here, n1 is an integer from 10 to 150, and n2 is an integer from 10 to 150)

The composite sheet of the present invention can have excellent properties in terms of thermal conductivity and workability by including a compound represented by Formula 3 by reacting the compound represented by Formula 1 with the compound represented by Formula 2.

The conductive layer included in the composite sheet of the above embodiment may have an average density of 1.0 to 5.0 g/cc. If the average density of the conductive layer is less than 1.0 g/cc, thermal and electrical conductivity may be reduced, and if it exceeds 5.0 g/cc, the strength of the coating film may be reduced and the flexibility of the composite sheet may be reduced.

The higher the density of the conductive layer, the lower the content of pores contained in the conductive layer. For example, the porosity of the conductive layer may be 5.0% or less. If the porosity of the conductive layer exceeds 5.0%, the coating film strength, thermal conductivity, and electrical conductivity may decrease.

Meanwhile, the conductive layer thickness may be preferably 5 to 400 μm, more preferably 10 to 300 μm, and most preferably 80 to 150 μm. If the thickness of the conductive layer is less than 5㎛, the bearing capacity of the composite sheet may be reduced due to the conductive layer being too thin. If it exceeds 400㎛, the flexibility of the composite sheet may decrease and thermal and electrical conductivity may decrease due to the inclusion of an excessively thick conductive layer.

(Example)

A primer layer was applied on aluminum with a thickness of 40 ㎛ as a base material, and a conductive coating composition was coated on it to form a conductive layer, thereby producing a composite sheet with a total thickness of 152 ㎛. Shore hardness (Shore A) was measured under the condition of a total specimen thickness of 1 mm, heat resistance measurement conditions were measured at 1,100 kPa with a DynTIMS equipment, and wear resistance measurement conditions were measured at 50 rpm/500 cycles with a Taber wear tester CS-10 wheel. Measured. Filler 1 used natural graphite powder with an average particle size (D50) of 10 ㎛, Filler 2 used spherical aluminum oxide (Al2O3) powder with an average particle size (D50) of 10 ㎛, and Filler 3 had an average particle size (D50) of 10 ㎛. Nickel-coated copper powder with a thickness of 10 ㎛ was used. A compound represented by Formula 1 (n1 is 135) was used as the main agent, and a compound represented by Formula 2 (n2 was 84) was used as a curing agent. The additives were epoxy silane-based adhesion agent, methyl silane-based coupling agent, and carbon black pigment mixed in a weight ratio of 1:1:0.5. In the composite sheets of Examples and Comparative Examples, other conditions were the same and the conductive layer conditions were varied.

[Table 1] is a table showing shore hardness (A), heat resistance (B), wear resistance, and the ratio of shore hardness and heat resistance (A/B) when the ratio of base material and hardener is different.

division	unit	Comparative Example 1	Comparative example 2	Example 1	Example 2	Example 3	Example 4	Example 5	Example 6	Comparative example 3
Filler 1 content	weight part	56.15	56.15	56.15	56.15	56.15	56.15	56.15	56.15	56.15
subject content	weight part	27.53	25.69	24.09	22.67	21.41	20.28	19.27	18.36	16.06
hardener content	weight part	11.01	12.85	14.45	15.87	17.13	18.26	19.27	20.18	22.48
additive content	weight part	5.31	5.31	5.31	5.31	5.31	5.31	5.31	5.31	5.31
Sum	-	100	100	100	100	100	100	100	100	100
subject: hardener	-	1:0.4	1:0.5	1:0.6	1:0.7	1:0.8	1:0.9	1:1	1:1.2	1:1.4
Shore Hardness (A)	Shore A	30	40	50	55	60	80	90	95	99
Thermal resistance (B)	K/W	0.71	0.75	0.86	0.97	1.01	1.03	1.07	1.11	1.52
Wear resistance rate	%	4.88	3.55	2.96	2.88	2.72	2.68	2.44	2.06	2.04
A/B	Shore A /(K/W)	42	53	58	57	59	78	84	86	65

As shown in [Table 1], it can be seen that Examples 1 to 6 exhibit superior properties in terms of shore hardness, heat resistance, and wear resistance compared to Comparative Examples 1 to 3.

[Table 2] is a table showing shore hardness (A), thermal resistance (B), wear resistance, and ratio of shore hardness and thermal resistance (A/B) when the ratio of base material and hardener is varied at various conductive layer densities. am.

division	unit	Comparative Example 4	Example 7	Comparative Example 5	Comparative Example 6	Example 8	Comparative example 7	8 in comparison	Example 9			Comparative Example 9
Filler 1 content	wt%	56.15	56.15	56.15	14.04	14.04	14.04	9.36	9.36			9.36
Filler 2 content	wt%				42.11	42.11	42.11
Filler 3 content	wt%							46.79	46.79			46.79
subject content	wt%	25.69	19.27	16.06	25.69	19.27	16.06	25.69	19.27			16.06
hardener content	wt%	12.85	19.27	22.48	12.85	19.27	22.48	12.85	19.27			22.48
additive content	wt%	5.31	5.31	5.31	5.31	5.31	5.31	5.31	5.31			5.31
Sum	-	100	100	100	100	100	100	100	100			100
subject: hardener	-	1:0.5	1:1	1:1.4	1:0.5	1:1	1:1.4	1:0.5	1:1			1:1.4
density	g/cc	1.0	1.0	1.0	3.0	3.0	3.0	5.0	5.0			5.0
Shore Hardness (A)	Shore A	45	85	99	45	91	99	45	93			99
heat resistance (B)	K/W	1.34	0.96	1.62	1.04	1.08	1.59	1.02	1.10			1.65
Wear resistance rate	%	3.68	2.46	2.04	3.47	2.42	2.01	3.85	1.98			1.88
A/B	Shore A /(K/W)	34	89	61	43	84	62	44	85			60

As shown in [Table 2], it can be seen that Examples 7 to 9 exhibit superior properties in terms of shore hardness, heat resistance, and wear resistance compared to Comparative Examples 4 to 9.

[Table 3] is a table showing shore hardness (A), heat resistance (B), wear resistance, and the ratio of shore hardness and heat resistance (A/B) when the ratio of base material and hardener is varied at various porosity.

division	unit	Comparative Example 10	Example 10	Comparative Example 11	Comparative Example 12	Example 11	Comparative Example 13	Comparative Example 14	Example 12	15 in comparison
porosity	%	One	One	One	3	3	3	5	5	5
Shore Hardness	Shore A	45	88	99	45	90	99	45	92	99
heat resistance	K/W	0.92	1.05	1.54	1.04	1.08	1.59	1.20	1.24	1.82
Wear resistance rate	%	3.84	1.94	1.88	3.92	2.23	2.14	3.85	2.68	2.34
A/B	Shore A /(K/W)	49	84	64	43	83	62	38	74	54

As shown in [Table 3], it can be seen that Examples 10 to 12 exhibit superior properties in terms of shore hardness, heat resistance, and wear resistance compared to Comparative Examples 10 to 15.

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 (12)

1. write;

   A primer layer formed on at least one side of the substrate; and

   A composite sheet having excellent thermal and electrical conductivity, including a conductive layer formed on the primer layer and containing a carbon-based compound and a polymer binder,

   A composite sheet with excellent thermal and electrical conductivity, characterized in that Shore A hardness is in the range of 50 to 95 Shore A.
2. In claim 1,

   A composite sheet with excellent thermal and electrical conductivity, wherein the polymer binder includes a base material, a curing agent, and a filler.
3. In claim 2,

   A composite sheet with excellent thermal and electrical conductivity, characterized in that the weight ratio of the base material and the curing agent is 1:0.6 to 1.2.
4. In claim 2,

   The main agent is a compound containing a vinyl group, the curing agent is a compound containing a hydrogen group, and crosslinking occurs when the vinyl group of the main agent reacts with the hydrogen group of the curing agent. A composite sheet with excellent thermal and electrical conductivity.
5. In claim 1,

   A composite sheet with excellent thermal and electrical conductivity, characterized in that the weight ratio of the carbon-based compound and the polymer binder is 1:0.2 to 30.
6. In claim 1,

   The carbon-based compound is one or more selected from the group consisting of graphite, carbon nanotubes (CNT), graphene, graphene oxide, carbon fiber and fullerene, carbon, nanocarbon, and carbon black. A composite sheet with excellent thermal and electrical conductivity, comprising:
7. In claim 1,

   The polymer binder has thermal and electrical conductivity, characterized in that it is at least one selected from the group consisting of a thermosetting silicone rubber compound, a one-component thermosetting silicone binder, a two-component thermosetting silicone binder, an acrylic resin, an epoxy resin, a urethane resin, and a urea resin. Excellent composite sheet.
8. In claim 1,

   A composite sheet with excellent thermal and electrical conductivity, wherein the conductive layer has a thickness of 5 to 450 ㎛.
9. In claim 1,

   A composite sheet with excellent thermal and electrical conductivity, wherein the conductive layer has an average density of 1.0 to 5.0 g/cc.
10. In claim 1,

    A composite sheet with excellent thermal and electrical conductivity, wherein the conductive layer has a porosity of 5% or less.
11. In claim 1,

    A composite sheet with excellent thermal and electrical conductivity, characterized in that the thermal resistance of the composite sheet is in the range of 0.8 to 1.3 K/W.
12. In claim 1,

    A composite sheet with excellent thermal and electrical conductivity, characterized in that the ratio of (shore A hardness) / (thermal resistance) of the composite sheet is in the range of 50 to 90 (shore A) / (K / W).