JP5458488B2 - Conductive film, sputtering target using the same, and method for producing sputtering target - Google Patents

Description

  The present invention relates to a conductive film, a sputtering target in which a bare target body and a backing plate are bonded by a conductive film, and a method for manufacturing the sputtering target.

  Currently, sputtering is widely used industrially for forming thin films used in semiconductor devices, flat displays, recording media, and the like. The thin film material (bare target body) used in the sputtering method needs to be fixed in the vacuum chamber apparatus in the sputtered thin film forming process, but at this time, it can be used by being joined to a backing plate used as an electrode. It is common. Conventionally, expensive indium solder has been mainly used for joining the bare target body and the backing plate (for example, Patent Document 1). Further, in this joining, all sides of the bare target body need to be joined to the backing plate. However, since this joining process is relatively complicated, a cheaper and simpler joining method has been demanded.

Japanese Patent Laid-Open No. 11-200028

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a conductive film, in particular, a conductive film that can be bonded by heating the bare target body and the backing plate at a relatively low temperature. A sputtering target obtained by bonding a bare target body and a backing plate with the film, and a method for manufacturing the sputtering target are provided.

  As a result of intensive studies, the present inventors have found that a specific polyolefin grafted with an unsaturated carboxylic acid is effective as a medium for firmly adhering to metal and dispersing conductive fine particles, and further containing conductive fine particles It has been found that by forming a specific polyolefin grafted with unsaturated carboxylic acid to be a film, the bare target body and the backing plate can be easily heated and bonded, and the conductivity between the bare target body and the backing plate can be secured. The present invention has been reached. That is, the present invention comprises a conductive film comprising a modified polyolefin grafted with an unsaturated carboxylic acid containing conductive fine particles, a bare target body and a backing plate bonded together using a conductive film. The sputtering target characterized by these, and its manufacturing method.

  Hereinafter, the present invention will be described in detail.

  The conductive film of the present invention comprises a modified polyolefin grafted with an unsaturated carboxylic acid containing conductive fine particles.

  The modified polyolefin grafted with an unsaturated carboxylic acid in the conductive film of the present invention (hereinafter referred to as an unsaturated carboxylic acid grafted polyolefin) refers to one obtained by grafting an unsaturated carboxylic acid onto a polyolefin.

  The unsaturated carboxylic acid grafted polyolefin is used to maintain the uniformity of electrical conductivity of the conductive film in the adhesive surface when the bare target body and the backing plate are bonded to each other. Preferably does not contain gel insoluble in xylene heated to 140 ° C.

  The graft amount of the unsaturated carboxylic acid in the unsaturated carboxylic acid grafted polyolefin is not particularly limited, but preferably 0.1 to 10% by weight in order to have sufficient adhesiveness and maintain the melt viscosity of the polyolefin moderately. More preferably, it is 0.5 to 8% by weight.

  The unsaturated carboxylic acid grafted polyolefin is, for example, an unsaturated carboxylic acid grafted polyethylene, an unsaturated carboxylic acid grafted ethylene / propylene copolymer, an unsaturated carboxylic acid grafted ethylene / butene copolymer according to the type of polyolefin as a raw material as described later. Examples include polymers, unsaturated carboxylic acid grafted ethylene / hexene copolymers, unsaturated carboxylic acid grafted ethylene / vinyl acetate copolymers, and unsaturated carboxylic acid grafted polypropylene.

  Examples of the unsaturated carboxylic acid include unsaturated monocarboxylic acids and derivatives thereof, unsaturated dicarboxylic acids and derivatives thereof, and acid anhydrides and derivatives of unsaturated dicarboxylic acids. Examples of unsaturated monocarboxylic acids include acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, and the like. Derivatives of unsaturated monocarboxylic acids include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl ( Examples include meth) acrylate, isopropyl (meth) acrylate, and butyl acrylate. Examples of unsaturated dicarboxylic acids include maleic acid, fumaric acid, itaconic acid, citraconic acid, and tetrahydrophthalic acid. Desaturated dicarboxylic acids include monomethyl maleate, dimethyl maleate, monoethyl maleate, and maleic acid. Examples include diethyl, monomethyl fumarate, dimethyl fumarate, monoethyl fumarate, and diethyl fumarate. Examples of the acid anhydrides of unsaturated dicarboxylic acid and derivatives thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride and the like. These may be used alone or in combination of two or more. In particular, from the viewpoint of adhesiveness, maleic anhydride alone or a combination of maleic anhydride and (meth) acrylic acid esters is preferable.

  As the conductive fine particles contained in the unsaturated carboxylic acid grafted polyolefin, there is no limitation as long as conductivity is exhibited after adhesion without impairing the smoothness of the film surface. For example, gold, silver, copper, molybdenum, nickel , Carbon, tin, indium, palladium, rhodium, osmium, ruthenium, iridium, aluminum, iron, indium, magnesium, platinum, silicon, tin, zinc, cobalt, chromium, titanium, tantalum, tungsten, carbon black, etc. Are preferably gold, silver, copper, palladium, rhodium, ruthenium, iridium, platinum, cobalt, nickel, and carbon black. One or more kinds of fine particles selected from these particles are exemplified. The fine particles referred to in the present invention are those having an average particle diameter of 0.5 nm to 50 μm.

  The average particle diameter of the conductive fine particles may be appropriately selected depending on the application, and is not particularly limited. However, in order to impart conductivity, it is preferable to use nanoparticles, and an average particle diameter of 1 to 50 nm is suitably used. If necessary, particles having different average particle diameters can be mixed and used. In particular, it is known that metal particles having an average particle size of nano-size cause spontaneous fusion due to a melting point lowering phenomenon, and metal particles having a small average particle size can be selected according to the purpose.

  The content of the conductive fine particles in the unsaturated carboxylic acid grafted polyolefin can be appropriately changed depending on the purpose, but in order to maintain the conductivity and the adhesive strength, the conductive fine particles are used with respect to 100 parts by weight of the unsaturated carboxylic acid grafted polyolefin. Is preferably 30 to 99 parts by weight.

  The unsaturated carboxylic acid grafted polyolefin may contain other resins, elastomers or rubber components, and various additives for the purpose of improving properties such as adhesion. In addition, the conductive film of the present invention may contain other resins, elastomers or rubber components, and various additives for the purpose of improving properties such as adhesion.

  Examples of the other resin include not only the above polyolefin resin not subjected to graft reaction, but also styrene resins such as polystyrene, poly-α-methylstyrene, polystyrene-acrylonitrile copolymer, styrene-acrylonitrile-butadiene resin, and the like. Acrylic resins such as acrylic acid and polymethyl methacrylate-polyvinyl chloride resin, polyvinylidene chloride resin, polyamide, polyester, polycarbonate resin, fluorine resin, silicone resin, polyphenylene oxide resin (PPO), polyphenylene sulfide resin (PPS), polyimide, polysulfone, polyethersulfone, polyether-etherketone, polybutylene terephthalate resin (PBT), polyoxymethylene resin (POM), epoxy resin Polyurethanes, urea resins, phenol resins, melamine resins, cellulose, and petroleum resins. If necessary, it is possible to chemically react a reactive functional group or other resin having a terminal group with the unsaturated carboxylic acid group of the present invention, utilizing the physical interaction between these functional groups. Blending is possible. Furthermore, a coupling agent such as a silane coupling agent or a titanium coupling agent can be added as a third component to improve compatibility with other resins, or to improve adhesiveness.

  Examples of the elastomer or rubber component include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, epichlorohydrin rubber, nitrile rubber, and acrylic rubber. , Urethane rubber, silicone rubber, fluorine rubber and the like. Further, as thermoplastic elastomer (TPE), SBS, SIS and other styrene TPE (SBC), polyolefin TPE (TPO), urethane TPE (TPU), polyester elastomer (TPEE), polyamide elastomer (TPA), Examples include silicone-based TPE and fluorine-based TPE.

  The following are mentioned as various additives. Examples of the antioxidant include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, and composite antioxidants thereof. Other stabilizers include organic phosphite stabilizers, thioether stabilizers, hindered amine light stabilizers, and the like. Moreover, as a filler, a spherical filler, a plate-like filler, a fibrous filler etc. are mentioned, for example. Examples of adhesives include liquid and solid bisphenol A epoxy resins, epoxy cresol novolacs, epoxy phenol novolacs and mixtures of bisphenol A epoxy resins and epoxy cresol novolacs or epoxy phenol novolacs, bisphenol F epoxy resins, aliphatic epoxy resins, and the like. Can be mentioned. Examples of the epoxy crosslinking agent include boron trifluoride complex compounds, dicyandiamide, polyamides, and polyamines. Examples of the flame retardant include brominated flame retardants such as ethylene bistetrabromophthalimide, decabromodiphenyl oxide, SAYTEX 8010, tetradecabromodiphenoxybenzene, antimony trioxide, antimony pentoxide, zinc borate, FIREBRAKE ZB, and the like. Flame retardant aids, chlorinated flame retardants such as DECLORONE PLUS, and the like. As a lubricant, higher fatty acid metal salts such as magnesium salts of higher fatty acids such as stearic acid, oleic acid, lauric acid, alkaline earth metal salts such as calcium salts and barium salts, cadmium salts, zinc salts, lead salts, and Alkali metal salts such as sodium salt, potassium salt and lithium salt can be used. Examples of other additives include colorants, natural oils, synthetic oils, waxes, plasticizers, nucleating agents, processing aids, and waxes.

  These other resins, elastomers or rubber components, and various additives can be contained within a range that does not impair the function of the conductive film provided in the present invention. The content is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the unsaturated carboxylic acid grafted polyolefin. Further, the content is preferably 0.13 to 20.9 parts by weight, more preferably 0.13 to 10.45 parts by weight, based on 100 parts by weight of the conductive film of the present invention.

  Examples of the raw material polyolefin include high density polyethylene (HDPE), medium density polyethylene (MDPE), low density polyethylene (LDPE), linear low density polyethylene (L-LDPE), and very low density polyethylene (V-LDPE). Etc. Examples of linear low density polyethylene (L-LDPE) include ethylene-α-olefin copolymers such as ethylene-1-butene copolymer, ethylene-1-hexene copolymer, and ethylene-1-octene copolymer. Can be mentioned. Other ethylene copolymers such as ethylene-4-methylpentene-1 resin, ethylene-vinyl acetate copolymer (EVA) and saponified products thereof, ethylene-vinyl alcohol resin (EVOH), ethylene-propylene copolymer (EPM) , Polypropylene homopolymer, polypropylene block copolymer, polypropylene random copolymer and the like.

  The polymerization method for synthesizing these polyolefins may be a generally known method, including high-pressure radical polymerization, medium-low pressure polymerization, solution polymerization, slurry polymerization, etc., and the catalyst used is a peroxide catalyst, Ziegler-Natta. Examples of the catalyst include metallocene catalysts, and polyolefins polymerized with these catalysts can be used.

  The melt mass flow rate (MFR) that is a measure of the molecular weight of the polyolefin is not particularly limited, but it is preferable in order to make the solubility in a solvent good even when heated and to maintain the material strength of the final graft reaction product. It is 0.01-50000 (g / 10min), More preferably, it is 0.01-100 (g / 10min).

  Although chlorinated polyolefin can be used, its production method is known. For example, a solution obtained by dissolving a halogen-based solvent such as carbon tetrachloride in contact with a chlorine-containing gas under ultraviolet irradiation is used to produce polyolefin. A chlorination method (for example, JP-A-47-8443), a method for chlorinating olefins by blowing chlorine gas into a slurry in which polyolefin particles are suspended in water (for example, Japanese Patent Publication No. 36-4745). Gazette), a method of chlorinating a polyolefin without using a radical generator, ultraviolet irradiation or the like by heating the polyolefin above its melting point without using a solvent and bringing it into contact with chlorine gas in a molten state ( For example, JP-A-3-199206) is disclosed. The chlorinated polyolefin used in the present invention can be produced by any of these methods.

  The unsaturated carboxylic acid grafted polyolefin in the conductive film of the present invention can be produced by grafting an unsaturated carboxylic acid onto the polyolefin using a radical generator in a halogen-based solvent.

  Examples of the halogen solvent include 1,1,2-trichloroethane, chloroform, carbon tetrachloride and the like. When 1,1,2-trichloroethane is used as the halogen-based solvent, commercially available 1,1,2-trichloroethane often contains 0.5 to 2.0% by weight of an alcohol compound and / or an epoxy compound. Is contained as an impurity. Here, the alcohol compound is a compound having a hydroxyl group, and examples thereof include ethyl alcohol and butyl alcohol. The epoxy compound is a compound having an epoxy group, such as 1,2-epoxypropane and 1,2 -Epoxybutane etc. are mentioned. In order to obtain an unsaturated carboxylic acid grafted polyolefin which is colorless and transparent, has good thermal stability and does not contain a gel, when 1,1,2-trichloroethane is used as a solvent, 1 It is preferable to remove in advance the alcohol compound and / or epoxy compound contained as impurities in 1,2-trichloroethane.

  As the radical generator, an azo compound or an organic peroxide is used. Examples of the azo compound include α, α-azobisisobutyronitrile, azobiscyclohexanecarbonitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), and the organic peroxide includes Examples include benzoyl peroxide, acetyl peroxide, t-butyl peroxide, and t-butyl perbenzoate.

  The amount of azo compound or organic peroxide added is not particularly limited, but the product maintains the graft amount of unsaturated carboxylic acid and prevents increase in melt viscosity of the resin to prevent deterioration of moldability. In order to maintain the quality, the amount is preferably 0.05 to 5 parts by weight, more preferably 0.05 to 3 parts by weight with respect to 100 parts by weight of the polyolefin.

  The reaction temperature is not particularly limited, but is preferably 40 to 130 ° C., more preferably 60 to 130 ° C. in order to increase the efficiency of the graft reaction and prevent coloring and crosslinking of the unsaturated carboxylic acid grafted polyolefin. The reaction pressure is not particularly limited, but is preferably 0 to 1 MPa, more preferably 0 to 0.7 MPa, in order to graft a sufficient amount of unsaturated carboxylic acid and to suppress the generation of gel to prevent deterioration in quality. is there. In this reaction, depending on the reaction temperature and the type of polyolefin to be reacted, the grafting reaction proceeds from a uniform solution state to a suspended state, but the grafting reaction proceeds in the uniform solution state as much as possible. It is preferable to select the temperature appropriately.

  After completion of the grafting reaction, a stabilizer is added as necessary. Stabilizers are preferably added to eliminate radicals generated during the grafting reaction and stop the grafting reaction. It is preferable to use an antioxidant that is usually added to the polyolefin. For example, a phenolic antioxidant or a phosphorus antioxidant. , Sulfur-based antioxidants, and composite antioxidants thereof are preferably used.

  As the reaction vessel used for the grafting reaction, a vessel used for a batch-type reaction can be used. Any material can be used as long as it can withstand the above reaction temperature and reaction pressure, and the material is usually made of stainless steel. If necessary, it is possible to use a glass lining and fluorine coating treated on the inner surface.

  For separation of the unsaturated carboxylic acid grafted polyolefin produced by the grafting reaction from the solvent, a commonly used method such as a drum dryer, steam distillation, vented extruder or the like can be used, but it is economical to use a drum dryer. Particularly preferred from the use. On the other hand, when the solvent used for the production of the conductive film of the present invention and the solvent for the graft reaction are the same, it is not necessary to isolate the unsaturated carboxylic acid grafted polyolefin from the reaction solution, and a reaction solvent is added. Alternatively, the concentration of the unsaturated carboxylic acid grafted polyolefin can be adjusted by a method such as concentrating the reaction solution, and the conductive fine particles can be added to the solution as it is, and a conductive film can be produced by a known method such as a solution casting method. .

  When the unsaturated carboxylic acid grafted polyolefin is separated from the solvent in the reaction step, after the reaction step is completed, the reaction solution is continuously fed from the reactor to, for example, a heated drum dryer, and the product is supplied. It can be isolated from the polymer solution. The temperature of the drum dryer at this time is preferably in the range of 120 to 200 ° C., more preferably 150 to 165 ° C. in order to suppress the coloring, thermal deterioration and crosslinking of the polymer while promoting drying. The polymer is a thin film that is peeled off from the drum and isolated.

  Further, 1,1,2-trichloroethane volatilized by the drum dryer can be recovered by using a recovery line installed at the upper part of the drum dryer and used again for the reaction.

  The time required for removing the solvent from the polymer solution by the drum dryer varies depending on the type of the solvent to be used and the temperature of the drum dryer, and can be appropriately selected, but is usually 10 seconds to 5 minutes.

  The isolated polymer can be processed into strings, sheets, strands or chips as required, and these primary shaped polymers can be further uniaxially or biaxially extruded as required. It is also possible to feed to a machine, melt and extrude the polymer, and pelletize by strand cutting or underwater cutting. The extrusion temperature in this case is not particularly limited, but is preferably 100 to 300 ° C., more preferably 150 to 300 ° C. in order to sufficiently melt the used polyolefin and smoothly extrude it, and to further suppress the decomposition and coloring of the polyolefin. 250 ° C.

  Various methods can be used for the production of the unsaturated carboxylic acid grafted polyolefin containing the conductive fine particles used in the conductive film of the present invention. That is, in addition to a known method, for example, a method of melt-kneading an unsaturated carboxylic acid grafted polyolefin and conductive fine particles using a twin screw extruder, the polyolefin is dissolved in the above-described solvent, and the resulting solution is electrically conductive. A method of adding fine particles and stirring and dispersing the solution in a temperature range from room temperature to preferably the boiling point of the solvent or less can be used. Unsaturated carboxylic acid-grafted polyolefin containing conductive fine particles can be produced by removing the solvent from the obtained solution using the method described above.

  The conductive film of the present invention is formed into a film by cast pressing, blow molding, etc., in which pellets of unsaturated carboxylic acid grafted polyolefin containing conductive fine particles are formed into a film in a molten state by a melt extrusion method, and also by a hot press or the like. In addition, after the pellets are dissolved in the organic solvent described above, a film can be formed by a solution casting method. At this time, the solution preparation can be performed using a reactor equipped with a stirrer or the like, but can also be performed using a machine such as a homogenizer. At this time, the dissolution temperature is not particularly limited, but usually it is preferably carried out from room temperature to the boiling point of the solvent used. Conductive fine particles are added to the obtained polyolefin solution, and the conductive fine particles are dispersed using an ultrasonic cleaner, a homogenizer, or the like. The temperature at this time is not particularly limited as long as it is a temperature at which the solvent does not volatilize, and is from room temperature to the boiling point of the solvent. Further, the conductive fine particles can be dispersed at a temperature equal to or higher than the boiling point of the solvent using a pressure vessel.

  The sputtering target of the present invention is obtained by bonding a bare target body and a backing plate using the conductive film of the present invention.

  The sputtering target of the present invention can be produced by bonding a bare target body and a backing plate using the conductive film of the present invention. The bonding method between the bare target body and the backing plate is not limited as long as the electrical conductivity of the both can be ensured. However, as an example of the bonding method, the backing plate, the conductive film of the present invention, and the bare target body are attached to this. After laminating in order, the method of melt-bonding by putting in a heating chamber under pressure as needed may be mentioned. The temperature at this time is not particularly limited as long as the backing plate and the bare target body can be bonded together, but is usually 90 ° C. to 300 ° C., more preferably 120 ° C. to 250 ° C. The bonding temperature is appropriately changed depending on the melting point of the conductive film to be used, but may be higher than the melting temperature of the film, or lower than the thermal decomposition temperature of the film. In order to ensure sufficient adhesive strength, for example, it is preferable that the bonding temperature is not higher than a temperature obtained by adding 100 ° C. to the melting point of the film. The bonding time is not particularly limited as long as the backing plate and the bare target body have a uniform and practically sufficient bonding strength, but is usually 1 to 60 minutes, preferably 1 to 30 minutes, and more preferably 1 to 10 minutes. . In bonding, the backing plate and the bare target body can be heated to the bonding temperature in advance, and in this case, the bonding time can be shortened. The pressure at the time of adhesion is not particularly limited as long as the backing plate and the bare target body have uniform and practically sufficient adhesion strength, but is usually 0.2 to 10 MPa, preferably 0.2 to 5 MPa, more preferably 0.2 to 3 MPa. In order to obtain sufficient sputtering performance, it is preferable that the conductive film of the present invention is bonded under the above pressure conditions so that it does not flow out of the bonding surface when melted.

  According to the present invention, a conductive film, in particular, a bare target body and a backing plate can be easily thermally bonded, and a conductive film capable of imparting electrical conductivity between them, a sputtering target excellent in economic efficiency with a backing plate bonded thereto, and A manufacturing method thereof can be provided.

  The present invention will be described in more detail with reference to the following examples. However, these are examples for helping understanding of the present invention, and the present invention is not limited to these examples.

<Raw material>
(1) Polyolefin EVA (ethylene / vinyl acetate copolymer): Ultrasen (registered trademark) 751 manufactured by Tosoh Corporation
Saponified EVA-1 (saponified product of ethylene / vinyl acetate copolymer): H-6410M manufactured by Tosoh Corporation
Saponified EVA-2 (saponified ethylene / vinyl acetate copolymer): H-6051K manufactured by Tosoh Corporation
(2) Reactive chemicals Benzoyl peroxide (BPO): NIPPER B manufactured by NOF Corporation
2,6-di-tert-butyl-p-cresol (BHT): API Corporation Yoshinox BHT
Maleic anhydride, acrylic acid, 1,1,2-trichloroethane, xylene: first grade reagent manufactured by Kanto Chemical Co., Ltd. (3) Conductive fine particles Copper fine particles: CUE08PB, manufactured by Kojundo Chemical Laboratory Co., Ltd. Average particle size 1 μm
Carbon black: Ketchen Black EC manufactured by Mitsubishi Chemical Corporation
<Measurement of gel fraction>
After 50 mg of polymer was added to 50 ml of xylene and dissolved at 140 ° C. for 12 hours, this solution was filtered through a 200 mesh stainless steel mesh (75 μm), and the unmelted portion on the wire mesh was dried at 105 ° C. for 5 hours. Calculated.

<Kneading of conductive fine particles>
Using a Laboplast Mill R30 manufactured by Toyo Seiki Co., Ltd., conductive fine particles were added to the modified polyolefin under the condition of a rotational speed of 60 rpm, and kneaded in a molten state to obtain a modified polyolefin containing conductive fine particles.

<Film forming>
By using a reciprocating compression molding machine WFA-50 manufactured by Shindo Metal Industry Co., Ltd. as a press molding machine, under the press conditions of heating temperature 150 ° C., pressure 10 MPa, 10 minutes, cooling temperature 30 ° C., pressure 10 MPa, 5 minutes. A press film having a thickness of 100 μm was obtained.

<T-type peel test>
The adhesive strength was evaluated by a T-type peel test under the condition of a tensile speed (peeling speed) of 300 mm / min using an orientec Tensilon universal testing machine RTE-1210.

Production Example 1
17,500 parts by weight of 1,1,2-trichloroethane and 2500 parts by weight of 26% sulfuric acid aqueous solution were placed in a 10-liter flask with a lower mouth and stirred vigorously. After standing, the lower organic layer was extracted. Next, 5 kg of the extracted organic layer and distilled water was placed in a 10-liter flask with a lower mouth and stirred vigorously, and after standing, the operation of extracting the lower organic layer was repeated three times to remove impurities 1-butanol and 1,2 -Excluding epoxy butane. Further, 150 parts by weight of molecular sieves 4A was added to the extracted organic layer, and dehydrated by stirring with a stirrer to obtain purified 1,1,2-trichloroethane (hereinafter referred to as purified TCE).

  A 4-liter glass reaction vessel was charged with 1750 parts by weight of purified TCE, 100 parts by weight of EVA, and 5 parts by weight of maleic anhydride. The temperature of the reactor was raised to 80 ° C., and then maintained at 80 ° C. for 4 hours to uniformly dissolve EVA. During this time, nitrogen gas was introduced into the reactor at a flow rate of 5 liters / minute to eliminate air mixed in the reactor. As a catalyst for the graft reaction, 0.16 parts by weight of BPO was dissolved in 100 parts by weight of purified TCE. While continuously adding this solution to the reactor, the graft reaction was carried out for 3 hours while maintaining the pressure of the reactor at 1 MPa. After completion of the reaction, the reactor pressure was returned to normal pressure, the reactor temperature was lowered to 70 ° C., 0.1 part by weight of BHT was added as a stabilizer, and the solution was heated to 160 ° C. Feeding to a dryer, the EVA grafted with maleic anhydride was separated from the solvent. The amount of gel in the product was 0% by weight as a result of analysis.

Production Example 2
A 4-liter glass reaction vessel was charged with 1750 parts by weight of purified TCE, 100 parts by weight of saponified EVA-1, and 7 parts by weight of maleic anhydride. The temperature of the reactor was raised to 80 ° C., and then maintained at 80 ° C. for 4 hours to uniformly dissolve saponified EVA-1. During this time, nitrogen gas was introduced into the reactor at a flow rate of 5 liters / minute to eliminate air mixed in the reactor. As a catalyst for the graft reaction, 0.2 part by weight of BPO was dissolved in 100 parts by weight of purified TCE. While continuously adding this solution to the reactor, the graft reaction was carried out for 3 hours while maintaining the pressure of the reactor at 1 MPa. After completion of the reaction, the reactor pressure was returned to normal pressure, the reactor temperature was lowered to 70 ° C., 0.1 part by weight of BHT was added as a stabilizer, and the solution was heated to 160 ° C. Feeding to a dryer, the saponified EVA-1 grafted with maleic anhydride was separated from the solvent. The amount of gel in the product was 0% by weight as a result of analysis.

Production Example 3
Saponified EVA-2 grafted with maleic anhydride was obtained in the same manner as in Production Example 2, except that saponified EVA-1 was replaced with saponified EVA-2. The amount of gel in the product was 0% by weight as a result of analysis.

Production Example 4
EVA grafted with acrylic acid was obtained in the same manner as in Production Example 1 except that maleic anhydride was replaced with acrylic acid. The amount of gel in the product was 0% by weight as a result of analysis.

Example 1
30 g of EVA grafted with maleic anhydride obtained in Production Example 1 (hereinafter referred to as modified EVA) and 9 g of carbon black were melt-kneaded at 150 ° C. for 10 minutes using a lab plast mill, and then cooled to cool the carbon black. Modified EVA was dispersed. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 100 microns. Using the obtained film, a copper plate of 60 mm × 13 mm × 5 mm was bonded as shown in FIG. At this time, the bonded area was 10 mm × 13 mm, and the bonded portion was sandwiched between two binder clips and bonded under the conditions shown in Table 1. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, when the tensile strength was measured with the autograph, all the samples showed the strength of 500 N or more and showed excellent adhesiveness.

実施例２
製造例１で得られた変性ＥＶＡ３０ｇ、銅微粒子１８ｇをラボプラストミルを用いて、１５０℃で１０分間、溶融混練後、冷却することにより銅微粒子が分散した変性ＥＶＡを得た。得られた樹脂を１８０℃でプレスすることにより厚みが１００ミクロンのフィルムを得た。カーボンブラックを含有するフィルムの代わりに、上記の方法により得られた銅微粒子を含有するフィルムを使用したこと以外は実施例１と同様にして試験を行なった。熱処理条件を表１に示す。接着後、銅板間の抵抗をテスターで測定したところすべてのサンプルで０Ωであり良好な導電性を示した。また、オートグラフで引張り強度を測定したところ、すべてのサンプルが５００Ｎ以上の強度を示し、優れた接着性を示した。

Example 2
30 g of modified EVA obtained in Production Example 1 and 18 g of copper fine particles were melt-kneaded for 10 minutes at 150 ° C. using a lab plast mill, and then cooled to obtain modified EVA in which the copper fine particles were dispersed. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 100 microns. The test was conducted in the same manner as in Example 1 except that instead of the film containing carbon black, a film containing copper fine particles obtained by the above method was used. Table 1 shows the heat treatment conditions. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, when the tensile strength was measured with the autograph, all the samples showed the strength of 500 N or more and showed excellent adhesiveness.

Example 3
An adhesion test using a carbon black-containing film was conducted in the same manner as in Example 1. However, in this example, an ITO plate (In ₂ O ₃ containing 10% by weight of SnO ₂ ) and a ZAO plate (ZnO containing 2% by weight of Al ₂ O ₃ ) were used as one copper plate at 200 ° C. for 1 hour. The heat treatment conditions were as follows. After bonding, when the resistance between the plates was measured with a tester, the ITO plate / copper plate adhesion sample was 5Ω, and the ZAO plate / copper plate adhesion sample was 1Ω, indicating good conductivity. Further, when the tensile strength was measured by an autograph, both samples were confirmed to have good adhesion without being peeled off even at a test force of 500 N.

Example 4
30 g of modified EVA obtained in Production Example 1 and 18 g of copper fine particles were melt-kneaded for 10 minutes at 150 ° C. using a lab plast mill, and then cooled to obtain modified EVA in which the copper fine particles were dispersed. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 100 microns. The test was conducted in the same manner as in Example 1 except that instead of the film containing carbon black, a film containing copper fine particles obtained by the above method was used. Table 1 shows the heat treatment conditions. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, when the tensile strength was measured with the autograph, all the samples showed the strength of 500 N or more and showed excellent adhesiveness.

Example 5
In the same manner as in Example 2, an adhesion test using a Cu powder-containing film was performed. However, in this example, an ITO plate (In ₂ O ₃ containing 10% by weight of SnO ₂ ) and a ZAO plate (ZnO containing 2% by weight of Al ₂ O ₃ ) were used as one copper plate at 200 ° C. for 1 hour. The heat treatment conditions were as follows. After bonding, when the resistance between the plates was measured with a tester, the ITO plate / copper plate adhesion sample was 0Ω, and the ZAO plate / copper plate adhesion sample was 1Ω, indicating good conductivity. Further, when the tensile strength was measured by an autograph, both samples were confirmed to have good adhesion without being peeled off even at a test force of 500 N.

Example 6
Saponified EVA-1 grafted with maleic anhydride obtained in Production Example 2 (hereinafter referred to as modified EVA-1), 30 g, and 15 g of copper fine particles were melt-kneaded at 150 ° C. for 10 minutes using a lab plast mill. Then, modified EVA-1 in which copper fine particles were dispersed was obtained by cooling. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 110 microns. Using the obtained film containing copper fine particles, a copper piece having a thickness of 1 mm, a width of 15 mm, and a length of 100 mm was adhered at 180 ° C. and a pressure of 0.2 MPa for 1 minute. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, the T-type peel strength measured by the autograph was 35 N / 15 mm, indicating excellent adhesiveness.

Example 7
Smelted EVA-2 grafted with maleic anhydride obtained in Production Example 3 (hereinafter referred to as modified EVA-2), 30 g, and carbon black 20 g were melt-kneaded at 150 ° C. for 10 minutes using a lab plast mill. Then, modified EVA-2 in which carbon black was dispersed was obtained by cooling. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 120 microns. Using the obtained film containing carbon black, a copper piece having a thickness of 1 mm, a width of 15 mm, and a length of 100 mm was bonded at 180 ° C. and a pressure of 0.2 MPa for 1 minute. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, the T-type peel strength measured by the autograph was 30 N / 15 mm, indicating excellent adhesiveness.

Example 8
30 g of EVA grafted with acrylic acid obtained in Production Example 4 (hereinafter referred to as modified EVA), 16 g of copper fine particles were melt-kneaded at 150 ° C. for 10 minutes using a lab plast mill, and then cooled to cool the copper fine particles. Modified EVA was dispersed. The obtained resin was pressed at 180 ° C. to obtain a film having a thickness of 105 μm. Using the obtained film containing copper fine particles, a copper piece having a thickness of 1 mm, a width of 15 mm, and a length of 100 mm was adhered at 180 ° C. and a pressure of 0.2 MPa for 1 minute. After bonding, when the resistance between the copper plates was measured with a tester, all the samples showed 0Ω, indicating good conductivity. Moreover, the T-type peel strength measured by the autograph was 30 N / 15 mm, indicating excellent adhesiveness.

  From Examples 1-8, it was confirmed that the conductive film of the present invention is excellent not only in metal-to-metal bonding but also in adhesion between metal and conductive oxide.

Example 9
Adhesion between a circular pure Al bare target body having a diameter of 76.2 mm and a thickness of 5 mm and a copper backing plate using an adhesive polymer sheet (carbon black content: 30% by weight) kneaded with carbon black ( Bonding) was performed.

  A carbon black-containing film having a diameter of about 70 mm was sandwiched between a pure Al bare target body and a copper backing plate and fixed with a vise, and then a heat treatment was performed at 200 ° C. for 1 hour for bonding. After bonding, it was set in a sputtering apparatus, Ar was used as a sputtering gas, and sputtering discharge characteristics (current-voltage characteristics) measurement, film formation rate measurement, and resistivity of a thin film formed by sputtering were measured at a pressure of 0.5 Pa. .

  As a comparison, the same measurement was performed for a pure Al target bonded using ordinary indium solder.

  FIG. 2 shows the measurement results of the discharge characteristics, and Table 2 shows the measurement results of the film formation rate and the thin film resistivity.

図２及び表２から本発明の導電性フィルムを使用してボンディングしたスパッタリングターゲットは、通常のインジウム半田を使用してボンディングを行なったターゲットと同様な特性を有することが分かり、ボンディング材料として使用可能であることが確認された。

2 and Table 2 show that the sputtering target bonded using the conductive film of the present invention has the same characteristics as the target bonded using ordinary indium solder, and can be used as a bonding material. It was confirmed that.

Example 10
Adhesion (bonding) between a pure Al sputtering target having a diameter of 76.2 mm and a thickness of 5 mm and a copper backing plate body using an adhesive polymer sheet (copper fine particle content: 60% by weight) kneaded with copper fine particles Was done.

  A copper fine particle-containing adhesive polymer sheet having a diameter of about 70 mm was sandwiched between a pure Al sputtering target and a copper backing plate and fixed with a vise, and then a heat treatment was performed at 200 ° C. for 1 hour for bonding. After bonding, it was set in a sputtering apparatus, Ar was used as a sputtering gas, and sputtering discharge characteristics (current-voltage characteristics) measurement, film formation rate measurement, and resistivity of a thin film formed by sputtering were measured at a pressure of 0.5 Pa. .

  As a comparison, the same measurement was performed for a pure Al target bonded using ordinary indium solder.

  FIG. 3 shows the measurement results of the discharge characteristics, and Table 3 shows the measurement results of the film formation rate and the thin film resistivity.

図３及び表３から本発明の導電性フィルムを使用してボンディングしたスパッタリングターゲットは、通常のインジウム半田を使用してボンディングを行なったターゲットと同様な特性を有することが分かり、ボンディング材料として使用可能であることが確認された。

It can be seen from FIG. 3 and Table 3 that the sputtering target bonded using the conductive film of the present invention has the same characteristics as the target bonded using ordinary indium solder, and can be used as a bonding material. It was confirmed that.

It is a figure which shows the sample structure of the adhesion test using the electroconductive film of this invention. It is a figure which shows the relationship between the electric current in the case of the sputter discharge in Example 9, and a voltage. It is a figure which shows the relationship between the electric current in the case of the sputter discharge in Example 10, and a voltage.

Claims (3)

Containing conductive fine particles, Ri modified polyolefin Tona the unsaturated carboxylic acid grafted with halogenated solvents, modified polyolefin grafted with an unsaturated carboxylic acid in the halogenated solvent is insoluble in xylene was heated to 140 ° C. A conductive film characterized by not containing any gel . Conductive fine particles are gold, silver, copper, molybdenum, nickel, carbon, tin, indium, palladium, rhodium, osmium, ruthenium, iridium, aluminum, iron, indium, magnesium, platinum, silicon, tin, zinc, cobalt, chromium The conductive film according to claim 1, wherein the conductive film is one or more fine particles selected from titanium, tantalum, tungsten, and carbon black. Conductive film according to claim 1 or claim 2, wherein with respect to the modified polyolefin 100 parts by weight of grafted unsaturated carboxylic acid, in that it contains 30 to 99 parts by weight conductive particles.

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