Electrostatic chuck film

Abstract

This invention relates to an electrostatic chuck film, and more particularly to an electrostatic chuck film comprising an adhesive layer formed on a conductive layer, and having electrical properties within a specified range and the thickness of each layer.

Description

Technical Field

[0001] The present invention relates to an electrostatic chuck film, and more particularly to an electrostatic chuck film comprising an adhesive layer formed on a conductive layer and having electrical properties within a specified range and thicknesses of each layer, so that one side can be picked up by the electrostatic chuck and the other side can be bonded. Prior Art

[0002] Usually, adhesive protective films are attached during the product production process to protect the surface of the product. Such adhesive protective films are particularly used in display panels such as liquid crystal panels, plasma display panels (PDP), etc., which constitute display devices such as mobile phones, computer monitors, TVs, and various billboards, as well as semiconductor packaging processes.

[0003] In the past, most processes used pressure to pick up films or products, but it is not possible to use pressure to pick up films or products in a vacuum state. Specifically, the semiconductor packaging process is in a vacuum state. In this state, adhesive force is used to pick up films or products, but there is a disadvantage that it is not easy to peel off, so special structures and characteristics such as electrostatic chucks are required.

[0004] Korean Patent No. 2208071 discloses a multilayer structure for electrostatic coupling of substrates, but has the disadvantage of requiring an external power source and its contact portion to charge the metal electrodes.

[0005] Furthermore, in the case of a product, in order to be able to pick up with the electrostatic chuck, additional structural elements need to be provided, but such structural elements may be unnecessary for the product or reduce the function of the product itself. Therefore, the industry is in great need of a pickup body with a new structure and characteristics that can solve this problem.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent document 1: KR 10-2208071 (Fraunhofer Gesellschaft zur Forderung der Angewandten Forschung eV) 2021.01.21. Summary of the invention

[0009] Problems that the invention aims to solve

[0010] The present invention is proposed to solve the above-mentioned problems, and its purpose is to provide an electrostatic suction cup film, which includes an adhesive layer formed on a conductive layer, having electrical properties within a specified range, so that one side can be picked up by an electrostatic suction cup and the other side can be bonded.

[0011] Furthermore, in addition to the above-mentioned explicit purposes, the present invention is also intended to achieve other purposes that can be easily proposed by a person skilled in the art from these purposes and the overall description of this specification.

[0012] Technical means to solve the problem

[0013] For the above-mentioned purpose, the electrostatic chuck film of the present invention is characterized by comprising: a substrate layer; a conductive layer formed on the substrate layer; and an adhesive layer formed on the conductive layer.

[0014] Furthermore, the substrate layer may be selected from the group consisting of polyethylene terephthalate, polyethylene, polyimide, acrylic resin, cycloolefin polymer, mixtures thereof, and copolymers thereof.

[0015] Furthermore, the electrostatic chuck film of the present invention may further include a release film formed on the adhesive layer.

[0016] Also, when a voltage of 1 kV is applied to the electrostatic chuck film, the surface resistance may be 1×10 11 Ω / sq to 1×10 13 Ω / sq.

[0017] Furthermore, when a voltage of 1 kV is applied to the laminate of the base material layer and the conductive layer, the surface resistance may be 1×10 3 Ω / sq to 1×10 7 Ω / sq.

[0018] Moreover, when a voltage of 1 kV is applied to the adhesive layer, the surface resistance can be greater than 1×10 13 Ω / sq.

[0019] Furthermore, under the conditions of 25° C. and 10 GHz, the dielectric loss of the electrostatic chuck film can be 0.02 to 0.1.

[0020] Furthermore, under the conditions of 25° C. and 10 GHz, the dielectric loss of the laminate of the substrate layer and the conductive layer can be 0.1 to 0.23.

[0021] Moreover, under the conditions of 25° C. and 10 GHz, the dielectric loss of the laminate of the substrate layer and the adhesive layer can be 0.007 to 0.009.

[0022] Furthermore, under the conditions of 25° C. and 10 GHz, the dielectric constant of the electrostatic chuck film can be 2.8 to 3.3.

[0023] Furthermore, under the conditions of 25° C. and 10 GHz, the dielectric constant of the laminate of the substrate layer and the conductive layer may be 3.0 to 3.5.

[0024] Moreover, under the conditions of 25° C. and 10 GHz, the dielectric constant of the laminate of the substrate layer and the adhesive layer can be 2.9 to 3.2.

[0025] Furthermore, the conductive layer can be selected from the group consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), carbon nanotubes (CNT), graphene, indium tin oxide (ITO), silver nanowires and combinations thereof.

[0026] Furthermore, a cross-linking reaction can occur within the conductive layer.

[0027] Furthermore, the conductive layer may be formed by cross-linking a mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane with an aziridine compound.

[0028] Furthermore, the aziridine compound may be selected from the group consisting of trimethylolpropane tris(2-methyl-1-aziridine)propionate, trimethylolpropane tris[3-(aziridin-1-yl)propionate], pentaerythritol tris[3-(1-aziridinyl)propionate], pentaerythritol tris(2-methyl-1-aziridine propionate) and mixtures thereof.

[0029] Moreover, the weight ratio of the polyurethane to the poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) of the conductive layer can be 1:9, 1.5:8.5 or 3:7.

[0030] Moreover, the weight ratio of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane to the aziridine compound of the conductive layer may be 100:8 to 63, 100:10 to 63, or 100:12 to 63.

[0031] Furthermore, the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane of the conductive layer may be a solution dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropanol, and a mixture thereof.

[0032] Furthermore, the solution may further comprise a stabilizer selected from the group consisting of ethylene glycol, sorbitol and a mixture thereof.

[0033] Moreover, the concentration of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and polyurethane dissolved in the solvent selected from the group consisting of water, ethanol, methanol, isopropanol and a mixture thereof can be 0.8 weight percent to 1.2 weight percent or 0.8 weight percent to 0.9 weight percent.

[0034] Furthermore, the thickness of the conductive layer may be 0.03 μm to 3 μm.

[0035] Furthermore, the adhesive layer can be selected from the group consisting of organic silicon, acrylic resin, urethane resin, rubber and a combination thereof.

[0036] Furthermore, a curing reaction may occur within the adhesive layer.

[0037] Furthermore, the adhesive layer can be formed by reacting a compound selected from the group consisting of organopolysiloxane containing vinyl groups at both ends, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and mixtures thereof with silane or a silane derivative.

[0038] Furthermore, the reaction of the compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and a mixture thereof with silane or a silane derivative may use platinum as a catalyst.

[0039] Moreover, the organopolysiloxane is a polydimethylsiloxane containing vinyl groups at both ends, and the content of the vinyl groups can be 0.02 mmol / g to 0.2 mmol / g, 0.1 mmol / g to 0.2 mmol / g, or 0.15 mmol / g to 0.2 mmol / g.

[0040] Furthermore, 1 to 2 hydrogen groups (-H) of the silane derivative may be substituted by an alkyl group having 1 to 2 carbon atoms.

[0041] Furthermore, the Si—H content of the silane or silane derivative may be 4 mmol / g to 16 mmol / g, 4 mmol / g to 10 mmol / g, or 4 mmol / g to 5 mmol / g.

[0042] Furthermore, the molar ratio of Si—H of silane or a silane derivative to vinyl groups contained at both ends of the compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and a mixture thereof may be 1 to 3.

[0043] Furthermore, the thickness of the adhesive layer may be 15 μm to 50 μm, 18 to 35 μm, or 20 to 25 μm.

[0044] Furthermore, the thickness of the substrate layer may be 25 μm to 100 μm, 33 μm to 70 μm, or 38 μm to 50 μm.

[0045] Furthermore, the conductive layer may be gravure coated on the substrate layer.

[0046] Furthermore, the conductive layer may be dried with hot air at 60° C. to 100° C. or 20 Hz to 35 Hz for 30 seconds to 90 seconds.

[0047] Furthermore, the adhesive layer may be slot coated or knife coated on the conductive layer.

[0048] Furthermore, the adhesive layer may be dried with hot air at 60° C. to 150° C. or 30 Hz to 35 Hz for 90 seconds to 180 seconds.

[0049] Comparison with the efficacy of previous technologies

[0050] According to the technical means for solving the problems of the present invention as described above, various effects including the following can be expected. However, the present invention does not necessarily have to exert all the effects described below to be effective.

[0051] The electrostatic chuck film of the present invention is prepared in the order of substrate layer-conductive layer-adhesive layer, and can be picked up by the electrostatic chuck in a vacuum state by appropriately adjusting electrical physical properties such as surface resistance, dielectric loss and dielectric constant and the thickness of each layer.

[0052] In particular, if the electrostatic chuck film of the present invention is attached to an electrostatic chuck, the other side can be bonded to a product such as a semiconductor wafer, and the wafer etc. to which the electrostatic chuck film of the present invention is attached can be easily peeled off through the electrostatic chuck as needed under a vacuum state, and the electrostatic chuck film of the present invention can be removed outside the vacuum state, thereby having the advantage of not causing a decrease in the function of the product. Simple diagram description

[0053] Figure 1 is a cross-sectional view showing an embodiment of the present invention; FIG. 2 is a cross-sectional view showing another embodiment of the present invention. Implementation

[0054] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0055] However, the following is only an example and detailed description of a specific embodiment, and the present invention can be modified in various ways and has various forms, so the present invention is not limited to the specific embodiments of the examples. It should be understood that the present invention includes all modifications, equivalents and substitutes included in the concept and technical scope of the present invention.

[0056] Furthermore, in the following description, many specific matters such as specific structural elements are described, which are provided only to facilitate a more comprehensive understanding of the present invention, and it is obvious to a person skilled in the art that the present invention can be implemented even without such specific matters. Furthermore, when describing the present invention, when it is judged that the specific description of the relevant well-known function or structure unnecessarily obscures the main purpose of the present invention, its detailed description will be omitted.

[0057] Moreover, the terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. Unless otherwise defined, the terms used in the present invention, including technical or scientific terms, have the same meanings as those generally understood by those with ordinary knowledge in the technical field to which the present invention belongs. Terms defined in commonly used dictionaries should be interpreted as having meanings consistent with the meanings in the context of the relevant technology, and should not be interpreted as overly formalized meanings unless clearly defined in the present invention.

[0058] In the present invention, an expression in the singular includes an expression in the plural unless otherwise clearly meant in the context.

[0059] In the present invention, unless otherwise specified, % represents weight percentage, and molecular weight not separately specified represents weight average molecular weight.

[0060] In the present invention, the terms "first", "second", etc. can be used to describe a variety of structural elements, but the structural elements should not be limited by the terms. The terms are only used to distinguish one structural element from other structural elements. For example, without departing from the scope of the present invention, the first structural element can be named as the second structural element, and similarly, the second structural element can also be named as the first structural element.

[0061] In the present invention, terms such as "including", "containing" or "having" are intended to indicate the existence of features, structural elements (or components) recorded in the specification, but do not mean that one or more other features or structural elements do not exist or cannot be added.

[0062] When a pick-up adhesive film is attached to a product such as a semiconductor wafer by an electrostatic chuck, it can be easily peeled off even in a vacuum state, and the film can be removed outside the vacuum state, thereby preventing the function of the wafer etc. from being degraded. The object of the present invention is to provide an electrostatic chuck film that can exhibit these advantages.

[0063] In order to achieve the above-mentioned purpose, as shown in FIG1 , the electrostatic chuck film of the present invention is characterized in that it includes: a substrate layer 10; a conductive layer 20 formed on the substrate layer 10; and an adhesive layer 30 formed on the conductive layer 20. The main feature of the present invention is that the layers are arranged in this order.

[0064] Furthermore, the substrate layer 10 may be selected from the group consisting of polyethylene terephthalate, polyethylene, polyimide, acrylic resin, cycloolefin polymer, a mixture thereof, and a copolymer thereof.

[0065] Furthermore, as shown in FIG. 2 , the electrostatic chuck film of the present invention may further include a release film 40 formed on the adhesive layer 30 .

[0066] Furthermore, when a voltage of 1 kV is applied to the electrostatic chuck film, the surface resistance can be 1×10 11 Ω / sq to 1×10 13 Ω / sq. When it is less than this range, the dielectric loss increases and it cannot function as an electrostatic chuck. On the contrary, when it is greater than this range, although the dielectric loss decreases, the mobility of electrons decreases and it cannot function as an electrostatic chuck.

[0067] Furthermore, when a voltage of 1 kV is applied to the laminate of the base layer 10 and the conductive layer 20, the surface resistance may be 1×10 3Ω / sq to 1×10 7Ω / sq. When the surface resistance is less than this range, the dielectric loss increases and the laminate cannot function as an electrostatic chuck. On the contrary, when the surface resistance is greater than this range, the dielectric loss decreases but the mobility of electrons decreases and the laminate cannot function as an electrostatic chuck.

[0068] Furthermore, when a voltage of 1 kV is applied to the adhesive layer 30, the surface resistance can be greater than 1×10 13 Ω / sq. When it is less than 1×10 13 Ω / sq, the dielectric loss increases and the adhesive layer 30 cannot function as an electrostatic chuck.

[0069] Furthermore, the dielectric loss of the electrostatic chuck film can be 0.02 to 0.1 under the conditions of 25°C and 10 GHz. When it is less than this range, the mobility of electrons is reduced, so that an environment capable of generating positive charges and electrostatic force cannot be formed in the electrostatic chuck, and thus the electrostatic chuck cannot function. On the contrary, when it is greater than this range, the mobility of electrons increases, and the loss of negative charges increases before generating electrostatic force with the electrostatic chuck, and thus the electrostatic chuck cannot function.

[0070] Furthermore, the dielectric loss of the laminate of the substrate layer and the conductive layer may be 0.1 to 0.23 under the conditions of 25°C and 10 GHz. When the dielectric loss is less than this range, the problem that the electrostatic chuck is not separated from the electrostatic chuck due to the residual positive or negative charge of the electrostatic chuck may occur when the applied voltage of the electrostatic chuck is turned off due to the small dielectric loss. On the contrary, when the dielectric loss is greater than this range, the electrostatic attraction force is reduced or disappears due to the small number of electrons that can be combined with the electrostatic chuck.

[0071] Furthermore, the dielectric loss of the laminate of the substrate layer and the adhesive layer may be 0.007 to 0.009 at 25°C and 10 GHz. When the dielectric loss is less than this range, the problem that the positive charge or negative charge of the electrostatic chuck may remain and not separate from the electrostatic chuck when the applied voltage of the electrostatic chuck is turned off may occur due to the small dielectric loss. On the contrary, when the dielectric loss is greater than this range, the electrostatic attraction force is reduced or disappears due to the small number of electrons that can be combined with the electrostatic chuck.

[0072] Furthermore, under the conditions of 25°C and 10 GHz, the dielectric constant of the electrostatic chuck film may be 2.8 to 3.3. When it is less than this range, the electrostatic force cannot be generated with the electrostatic chuck due to the low dielectric constant. On the contrary, when it is greater than this range, the mobility of electrons cannot be ensured due to the high dielectric constant, and thus, the electrostatic force may not be generated with the electrostatic chuck.

[0073] Furthermore, the dielectric constant of the laminate of the substrate layer and the conductive layer may be 3.0 to 3.5 under the conditions of 25°C and 10 GHz. When it is less than this range, the electrostatic attraction force may be low or disappear due to the small amount of charge that can be stored. On the contrary, when it is greater than this range, the amount of stored charge is large, so there may be a problem that the electrostatic chuck is not separated or attracted by the electrostatic chuck even in the state where the applied voltage is turned off.

[0074] Furthermore, the dielectric constant of the laminate of the substrate layer and the adhesive layer may be 2.9 to 3.2 under the conditions of 25°C and 10 GHz. When it is less than this range, the electrostatic attraction may be low or disappear due to the small amount of charge that can be stored. On the contrary, when it is greater than this range, the amount of stored charge is large, so there may be a problem that the electrostatic chuck is not separated or attracted by the electrostatic chuck even when the applied voltage is turned off.

[0075] The main feature of the present invention is that the electrical physical properties such as surface resistance, dielectric loss or dielectric constant of each layer and the electrostatic chuck film combined therewith are precisely controlled so that it can be picked up as an electrostatic chuck.

[0076] Furthermore, the conductive layer 20 can be selected from the group consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS), carbon nanotubes (CNT), graphene, indium tin oxide (ITO), silver nanowires, and combinations thereof. The conductive layer 20 of the present invention is characterized in that, in addition to the electrical and physical properties, it must also have transparency.

[0077] Furthermore, in the electrostatic chuck film of the present invention, when the adhesive layer 30 is formed on the conductive layer 20, part of the conductive layer 20 may be removed due to a solvent that dissolves the substance constituting the adhesive layer 30. This occurs when the adhesive layer 30 is formed to a predetermined thickness by slit coating or blade coating, and in order to prevent this, the solvent resistance of the conductive layer 20 needs to be improved.

[0078] In order to improve the solvent resistance, a reaction between functional groups in the constituent materials of the conductive layer 20 may be induced, or a cross-linking reaction may be induced by introducing an additional cross-linking agent.

[0079] For example, when the conductive layer 20 of the present invention is a mixture of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) and water-dispersible polyurethane, a cross-linking reaction can be carried out by introducing an aziridine compound as a cross-linking agent.

[0080] Furthermore, the aziridine compound may be selected from the group consisting of trimethylolpropane tris(2-methyl-1-aziridine)propionate, trimethylolpropane tris[3-(aziridin-1-yl)propionate], pentaerythritol tris[3-(1-aziridinyl)propionate], pentaerythritol tris(2-methyl-1-aziridine propionate) and mixtures thereof.

[0081] Moreover, the weight ratio of polyurethane to poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT-PSS) of the conductive layer 20 may be 1:9, 1.5:8.5 or 3:7. When the content of PEDOT-PSS is less than this range, the surface resistance, dielectric loss and dielectric constant conditions that can function as an electrostatic chuck may not be met. On the contrary, when it is greater than this range, although the physical properties can be met, due to the small amount of polyurethane, it may not be fully cross-linked with the aziridine cross-linking agent, so not only can the solvent resistance not be ensured, but it is also not ideal from an economic perspective.

[0082] Furthermore, the weight ratio of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane to the aziridine compound of the conductive layer 20 may be 100:8 to 63, 100:10 to 63, or 100:12 to 63. When the weight ratio of the aziridine compound is less than the above range, the solvent resistance cannot be ensured because the carboxyl group of the water-dispersible polyurethane is not fully cross-linked. On the contrary, when the weight ratio is greater than the above range, the unreacted aziridine compound may migrate to the surface with time and temperature, which is not ideal from an economical perspective.

[0083] Furthermore, the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) and water-dispersible polyurethane of the conductive layer 20 may be a solution dissolved in a solvent selected from the group consisting of water, ethanol, methanol, isopropyl alcohol, and a mixture thereof.

[0084] Furthermore, the solution may further comprise a stabilizer selected from the group consisting of ethylene glycol, sorbitol and a mixture thereof.

[0085] Furthermore, the concentration of the mixture of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) and polyurethane dissolved in the solvent selected from the group consisting of water, ethanol, methanol, isopropanol and mixtures thereof may be 0.8 to 1.2 weight percent or 0.8 to 0.9 weight percent. When the concentration of the solution is less than this range, coating stripes may appear on the coating surface because the particles of PEDOT-PSS may be exposed to the surface. On the contrary, when it is greater than this range, the solid content is reduced, so when the wet thickness is increased, the surface may be uneven due to the fluidity of the coating solution on the coating surface.

[0086] Furthermore, the thickness of the conductive layer 20 may be 0.03 μm to 3 μm. When the thickness of the conductive layer is less than this range, the surface resistance is high and the dielectric loss is reduced, which may result in the inability to function as an electrostatic chuck. On the contrary, when the thickness of the conductive layer is greater than this range, the surface resistance is reduced and the dielectric loss is increased, which may result in the inability to function as an electrostatic chuck.

[0087] Furthermore, the adhesive layer 30 can be selected from the group consisting of organic silicon, acrylic resin, urethane resin, rubber and a combination thereof.

[0088] Furthermore, the adhesive layer 30 can be formed by reacting a compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and a mixture thereof, which has vinyl groups at both ends, with silane or a silane derivative, and in this case, platinum is preferably used as a catalyst. The present invention is characterized in that an addition reaction (curing) step is particularly applied to increase the degree of curing and reduce the dielectric constant.

[0089] Moreover, the organopolysiloxane is a polydimethylsiloxane containing vinyl groups at both ends, and its molecular weight is 600,000 to 700,000 in terms of weight average molecular weight, and 300,000 to 400,000 in terms of number average molecular weight, and the content of the vinyl group can be 0.02 mmol / g to 0.2 mmol / g, 0.1 mmol / g to 0.2 mmol / g, or 0.15 mmol / g to 0.2 mmol / g. When the content of the vinyl group is less than this range, it may not function as an electrostatic chuck as the dielectric loss value increases because it may not be fully cross-linked with Si-H. On the contrary, when it is greater than this range, it may not function as an electrostatic chuck as the dielectric loss value increases because the cross-linking density with Si-H increases.

[0090] Furthermore, 1 to 2 hydrogen groups (-H) of the silane derivative may be substituted by an alkyl group having 1 to 2 carbon atoms.

[0091] Furthermore, the Si-H content of the silane or silane derivative may be 4 mmol / g to 16 mmol / g, 4 mmol / g to 10 mmol / g, or 4 mmol / g to 5 mmol / g. When the Si-H content is less than the range, the dielectric loss may increase due to insufficient crosslinking with the vinyl group, whereas when the content is greater than the range, the unreacted Si-H groups may migrate to the surface of the adhesive layer.

[0092] Preferably, in the silane or silane derivative, 1 to 2 hydrogen groups (-H) of the hydrogen siloxane copolymer may be substituted by an alkyl group having 1 to 2 carbon atoms. More preferably, the silane or silane derivative may be an alkyl hydrogen siloxane-dialkyl siloxane copolymer, and more preferably, may be a methyl hydrogen siloxane-dimethyl siloxane copolymer.

[0093] Furthermore, the molar ratio (Si-H / vinyl) of Si-H of silane or silane derivative to vinyl groups contained at both ends of the compound selected from the group consisting of organopolysiloxane, chlorosilane, alkylalkoxysilane, sulfursilane, aminosilane, epoxysilane and mixtures thereof may be 1 to 3. When the molar ratio of Si-H / vinyl is larger than this range, although the crosslinking density increases, out-gassing occurs due to hydrogen generated when the amount of Si-H that does not react with the vinyl group increases. On the contrary, when it is smaller than this range, the crosslinking density and dielectric constant decrease due to the decrease in crosslinking points with the vinyl group, and the dielectric loss increases, so that the electrostatic chuck cannot function as it does.

[0094] Moreover, the thickness of the adhesive layer 30 may be 15 μm to 50 μm, 18 to 35 μm, or 20 to 25 μm. When the thickness of the adhesive layer 30 is less than the range, the dielectric loss may increase and may not function as an electrostatic chuck. On the contrary, when the thickness of the adhesive layer 30 is greater than the range, the dielectric loss may decrease and may not function as an electrostatic chuck.

[0095] Furthermore, the thickness of the substrate layer 10 may be 25 μm to 100 μm, 33 μm to 70 μm, or 38 μm to 50 μm. When the thickness of the substrate layer 10 is less than this range, wrinkles may appear due to shrinkage during the thermal process of coating, which may lead to poor appearance. On the contrary, when the thickness is greater than this range, the dielectric loss is reduced and it may not function as an electrostatic chuck.

[0096] The main feature of the present invention is that the thickness of each layer constituting the present invention is precisely controlled so that the present invention can function as an electrostatic chuck.

[0097] Furthermore, the conductive layer 20 may be gravure coated on the substrate layer 10 .

[0098] Furthermore, the conductive layer 20 may be dried for 30 seconds to 90 seconds using hot air at 60° C. to 100° C. or 20 Hz to 35 Hz. When the drying time or drying temperature is less than this range, insufficient drying may result in incomplete curing or solvent volatilization, which may affect electrical physical properties such as dielectric constant.

[0099] Furthermore, the adhesive layer 30 may be applied on the conductive layer 20 by slit coating or blade coating.

[0100] Furthermore, the adhesive layer 30 may be dried for 90 seconds to 180 seconds using hot air at 60° C. to 150° C. or 30 Hz to 35 Hz. When the drying time or drying temperature is less than this range, insufficient drying may result in incomplete curing or solvent volatilization, which may affect electrical physical properties such as dielectric constant.

[0101] Hereinafter, embodiments of the present invention will be described.

[0102] Example

[0103] Preparation Example: Conductive Layer

[0104] At room temperature and pressure, a 0.8 wt % aqueous solution of a mixture of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonic acid) (PEDOT-PSS) and a water-dispersible polyurethane (PEDOT-PSS: polyurethane = 1:9 wt %) was cross-linked with different concentrations (0 wt %, 0.05 wt %, 0.09 wt %, 0.1 wt %, 0.3 wt %, 0.5 wt % and 0.6 wt %) of pentaerythritol tris[3-(1-aziridinyl)propionate] for 45 minutes and then gravure coated on a polyethylene terephthalate substrate layer having a thickness of 50 μm, and dried with 35 Hz hot air at 60°C for 20 seconds, 80°C for 20 seconds and 100°C for 20 seconds to form a conductive layer having a thickness of 0.03 μm.

[0105] Test Example 1: Solvent resistance of conductive layer

[0106] When the applied voltage was 1 kV, the surface resistance of the conductive layer of the preparation example was measured using a surface resistance meter (Wolfgang, Germany), and a microfiber cloth soaked with methyl ethyl ketone (MEK) or ethanol was wound around an 800 g steel rod and brought into contact with the surface of the conductive layer, and then a 300 g weight was placed on the steel rod and rubbed 15 cm in one direction, and this was repeated 3, 5, 7, 10, 15, and 20 times, respectively, and then when the applied voltage was 1 kV, the surface resistance of the conductive layer was measured using a surface resistance meter (Wolfgang, Germany). The results are shown in Table 1.

[0107] Table 1 Surface resistance (Ω / sq) Aziridine concentration (wt%) Solvents frequency 0 0.05 0.09 0.1 0.3 0.5 0.6 - - 3.44×10 5 2.31×10 5 3.11×10 5 4.16×10 5 3.41×10 5 3.12×10 5 NG MEK 3 6.82×10 7 5.33×10 5 4.18×10 5 6.12×10 5 5.41×10 5 4.16×10 5 Ethanol 3 8.43×10 6 5.72×10 5 3.84×10 5 6.55×10 5 5.62×10 5 3.54×10 5 5 5.23×10 7 8.81×10 5 4.21×10 5 5.26×10 5 4.98×10 5 3.89×10 5 7 3.34×10 9 1.24×10 7 4.82×10 6 8.21×10 5 5.82×10 5 6.52×10 5 10 5.39×10 10 6.39×10 5 5.69×10 6 7.42×10 5 6.11×10 5 6.51×10 5 15 5.51×10 11 3.21×10 11 5.66×10 7 9.24×10 5 6.89×10 5 6.89×10 5 20 9.91×10 12 8.81×10 12 8.23×10 9 4.29×10 6 4.83×10 6 1.32×10 6

[0108] In Table 1, when the concentration of pentaerythritol tris[3-(1-aziridinyl)propionate] was 0.6 wt%, the surface gelled and had a poor appearance. The test results showed that when the concentration of pentaerythritol tris[3-(1-aziridinyl)propionate] was 0.1 wt% to 0.5 wt%, the surface resistance was kept low even after repeated rubbing with a solvent, and thus it was judged to be solvent-resistant.

[0109] Examples 1 to 8, Comparative Examples 1 and 2: Conductive Layer + Adhesive Layer

[0110] At room temperature and pressure, 27 g of polydimethylsiloxane (weight average molecular weight of 650,000) containing 0.2 mmol / g vinyl groups at both ends and 3 g of methylhydrogensiloxane-dimethylsiloxane copolymer (weight average molecular weight of about 2500) having a Si-H content of 4 mmol / g were reacted for 200 minutes using 0.5 g / kg aqueous platinum solution in 9.5 g / kg toluene as a catalyst, and the product was slit coated onto the conductive layer of the preparation example, and dried with 35 Hz hot air at 60°C for 50 seconds, at 110°C for 50 seconds, and at 150°C for 50 seconds to form an adhesive layer with a thickness of 20 μm (Example 1). The thickness of the conductive layer is changed to 0.02μm (Comparative Example 1), 0.09μm (Example 2), 0.15μm (Example 3), 0.3μm (Example 4), 0.9μm (Example 5), 1.5μm (Example 6), 2μm (Example 7), 3μm (Example 8) or 3.4μm (Comparative Example 2) to form an adhesive layer.

[0111] Test Example 2: Changes in surface resistance according to the thickness of the conductive layer

[0112] When the molar ratio of Si-H / vinyl group was 2 and the applied voltage was 1 kV, the surface resistance of Examples 1 to 8 and Comparative Examples 1 and 2 was measured using a surface resistance meter (Mitsubishi Chemical, Japan). The results are shown in Table 2.

[0113] Table 2 Conductive layer thickness (μm) Surface resistance (Ω / sq) Comparative Example 1 0.02 1.32×10 13 Example 1 0.03 7.54×10 12 Example 2 0.09 4.13×10 12 Example 3 0.15 1.39×10 12 Example 4 0.3 9.81×10 11 Example 5 0.9 8.84×10 11 Example 6 1.5 5.93×10 11 Example 7 2 4.39×10 11 Example 8 3 3.82×10 11 Comparative Example 2 3.4 2.83×10 10

[0114] The test results confirmed that when the thickness of the conductive layer was 0.03 μm to 0.3 μm, the surface resistance value was within the target range of 1×10 11 Ω / sq to 1×10 13 Ω / sq.

[0115] Experimental Example 3: Changes in electrical and physical properties according to the molar ratio of Si-H / vinyl

[0116] When the molar ratio of Si-H of the methylsilane of Example 1 to the vinyl groups contained at both ends of the polydimethylsiloxane was changed to 0.5 (Comparative Example 3), 1 (Example 9), 3 (Example 10) or 4 (Comparative Example 4), the surface resistance was measured using a surface resistance meter (Mitsubishi Chemical, Japan), and the dielectric loss and dielectric constant changes at 10 GHz were measured using a dielectric meter (Keysight Technologies, USA) to confirm whether it functions as an electrostatic chuck, and then the results are shown in Table 3.

[0117] Table 3 Comparative Example 3 Example 9 Example 10 Comparative Example 4 Si-H / Vinyl Molar Ratio 0.5 1 3 4 Surface resistance (Ω / sq) 1.13×10 12 4.43×10 11 5.21×10 12 7.23×10 12 Dielectric loss 0.052 0.043 0.032 0.018 Dielectric constant 3.5 3.2 2.89 2.75 Electrostatic chuck Can't Can Can Can't

[0118] The test results confirmed that when the molar ratio of Si-H / vinyl was 1 to 3, the dielectric loss value and dielectric constant value were within the target ranges of 0.02 to 0.1 and 2.8 to 3.3, respectively.

[0119] Experimental Example 4: Changes in electrical and physical properties according to layer sequence changes

[0120] The same process as in Example 1 was performed, except that the adhesive layer was formed under the base layer instead of on the conductive layer (Comparative Example 5), or after the preparation according to Example 1, a conductive layer was further formed under the base layer (Comparative Example 6), and then the dielectric loss and dielectric constant changes at 10 GHz were measured using a dielectric measuring instrument (Keysight Technologies, USA) to confirm whether it functions as an electrostatic chuck, and then the results are shown in Table 4. In this case, the molar ratio of Si-H / vinyl was 2, and the thickness of the conductive layer was 0.3 μm.

[0121] Table 4 Comparative Example 5 Comparative Example 6 Embodiment 11 Layer Order Conductive / substrate / bonding Conductive / substrate / conductive / adhesive Substrate / conductive / bonding Dielectric loss 0.127 0.133 0.084 Dielectric constant 3.31 3.33 3.15 Electrostatic chuck Can't Can't Can

[0122] The test results confirmed that only when the substrate layer-conductive layer-adhesive layer was prepared in the order of substrate layer-conductive layer-adhesive layer, the dielectric loss value and dielectric constant value were within the target ranges of 0.02 to 0.1 and 2.8 to 3.3, respectively.

[0123] The above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by equivalents without departing from the spirit and scope of the present invention, they should be included in the protection scope of the patent application of the present invention.

[0124] 10: Base material layer 20: Conductive layer 30: Adhesive layer 40: Release film

Claims

1. An electrostatic chuck film, wherein one side of the electrostatic chuck film can be picked up by an electrostatic chuck, and the other side can be adhered, wherein... include: Substrate layer; A conductive layer is formed on the substrate layer; An adhesive layer is formed on the conductive layer.

2. The electrostatic chuck film as described in claim 1, wherein, It also includes the release film formed on the adhesive layer.

3. The electrostatic chuck film as described in claim 1, wherein, When a voltage of 1 kV is applied to the electrostatic chuck film, the surface resistance is 1 × 10¹¹ Ω / sq to 1 × 10¹³ Ω / sq.

4. The electrostatic chuck film as described in claim 1, wherein, When a voltage of 1 kV is applied to the electrostatic chuck film, the dielectric loss is 0.02 to 0.1 kV.

5. The electrostatic chuck film as described in claim 1, wherein, When a voltage of 1 kV is applied to the electrostatic chuck film, the dielectric constant is 2.8 to 3.

3.

6. The electrostatic chuck film as described in claim 1, wherein, The conductive layer is selected from the group consisting of poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-polystyrenesulfonate (PEDOT-PSS), carbon nanotubes (CNTs), graphene, indium tin oxide (ITO), silver nanowires, and combinations thereof.

7. The electrostatic chuck film as described in claim 1, wherein, The adhesive layer is selected from the group consisting of organosilicon, acrylic resin, urethane resin, rubber, and combinations thereof.

8. The electrostatic chuck film as described in claim 1, wherein, The thickness of the substrate layer is 25 μm to 100 μm, 33 μm to 70 μm, or 38 μm to 50 μm.

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