Description

ADHEISIVE RESIN COMPOSITION AND DICING DIE BONDING FILM USING THE SAME

Technical Field

[1] The present invention relates to an adhesive resin composition applied to prepare a semiconductor package, and an adhesive film and its preparation process, a dicing die bonding film and a semiconductor device, using the same. The adhesive resin composition according to the present invention is characterized by comprising a) a multi-functional epoxy resin; b) a phenol resin, of which moisture absorptivity is 2.0 % by weight or less as treated in a condition of a temperature of 121 ⁰ C, a pressure of 2 atms and 100% RH for 48 hours; and c) a thermoplastic resin. Background Art

[2] Currently, according to high integration and high functionalization of semiconductor memories beginning flash memories embedded in cellular phones or mobile terminals, the MCP (Multi Chip Package) method is much used, in which multi semiconductor chips are laminated on a semiconductor substrate. In the MCP method, a film-like adhesive is used to bond the semiconductor chips and the semiconductor substrate, instead of conventional liquid epoxy paste (JP Unexamined Patent Publication Nos. H03-192178 and H04-234472, etc.).

[3] Meanwhile, there are a film part bonding method and a wafer back bonding method as a method of using said film- like adhesive.

[4] The film part bonding method is a method which comprises cutting or punching the film-like adhesive to make into parts adapted to chips, adhering it to a semiconductor substrate, picking up a chip from a wafer and die bonding thereon, and a semiconductor device is obtained through subsequent processes, such as wire bonding and molding processes (JP Unexamined Patent Publication No. H09-17810).

[5] In the wafer back bonding method, a semiconductor device is obtained via adhering the film-like adhesive to a water back, further adhering a dicing tape having a pressure-sensitive adhesive layer to the opposite side which does not bond with the wafer back, dicing said wafer to separate individual chips, picking up chips and die bonding them to a substrate for semiconductor, and then wire bonding and molding processes. However, in said wafer back bonding method, there were problems such as difficulty in transporting thin-shaped wafers, process increase, difficulty in adapting to various chip thicknesses and sizes, difficulty in thinning films and poor reliability for

high functional semiconductor devices.

[6] To solve said problems, a method is proposed, which comprises bonding to the wafer back a film having an adhesive and a pressure-sensitive adhesive as one layer (JP Unexamined Patent Publication Nos. H02-32181, H08-53655 and H10-8001). Said method does not perform twice the lamination process but is capable to do once, and causes no problem on transporting wafers, because wafer rings for supporting wafers are equipped with. Furthermore, an ultraviolet curing type pressure sensitive adhesive and a thermally curing type adhesive are mixed in the integrated dicing die bonding film composed of pressure sensitive adhesive-adhesive comprising compositions of said patent publications, and a base. Therefore, said pressure sensitive adhesive serves to support a wafer in the dicing process, and loses its adhesion strength after ultraviolet curing process, so that chips are easily picked up from the wafer. Meanwhile, said adhesive is cured in the die bonding process and may strongly bond chips to a substrate for semiconductor. However, said integrated dicing die bonding film has a problem that the base and the chips are not well peeled in the process of picking up semiconductor chips after dicing, by reacting the pressure sensitive adhesive layer and the adhesive layer in the film each other from preparation to use.

[7] A separated dicing die bonding film that a pressure sensitive adhesive and an adhesive are separated is proposed, which may be used as a dicing tape in the dicing process and as an adhesive in the die bonding process by solving such problems of integrated films. In said separated dicing die bonding film, the pressure sensitive adhesive and the adhesive are easily separated by curing it with ultraviolet or applying heat thereon after the dicing process, whereby it causes no problem on the semiconductor chip pickup process and provides a convenience that a film thickness may be thinned on the die bonding process. However, in a process of laminating the adhesive on the semiconductor wafer back, a process of applying heat is added unlike the conventional method that the pressure sensitive adhesive is adhered at room temperature, and not a few voids are also caused. In addition, there are problems that on heating, the wafer is bent due to high temperature, subsequent processes are not easily performed, and chips fly in the dicing process due to weak bond strength of the adhesive. Consequently, there is a problem in reliability of semiconductor package. Therefore, it is earnestly required to develop an adhesive resin composition for semiconductor which has excellent bond strength or filling property on semi-curing the adhesive resin composition applied to semiconductor packaging, so that the process fraction defective may be reduced, and which has excellent reliability such as heat

resistance, hygroscopic resistance and reflow crack resistance after manufacturing goods in the cured state. Disclosure of Invention Technical Problem

[8] The present invention is intended to comply with such requirements, and one object of the present invention is to provide an adhesive resin composition for semiconductor which has excellent bond strength or filling property on semi-curing the adhesive resin composition applied to semiconductor packaging, and which has excellent reliability such as heat resistance, hygroscopic resistance and reflow crack resistance on curing it. Technical Solution

[9] Another object of the present invention is to provide an adhesive film comprising said adhesive resin composition as an adhesive layer and a preparation process for the same.

[10] Another object of the present invention is to provide a dicing die bonding film comprising said adhesive film and a dicing tape.

[11] Another object of the present invention is to provide a semiconductor wafer using the dicing die bonding film.

[12] The other object of the present invention is to provide a semiconductor device using said adhesive film. Brief Description of the Drawings

[13] Hg. 1 is a cross-section view of an adhesive film according to one example of the present invention.

[14] Hg. 2 is a cross-section view of a dicing die bonding film according to one example of the present invention.

[15] Hg. 3 is a cross-section view of a semiconductor device according to one example of the present invention. Best Mode for Carrying Out the Invention

[16] The adhesive resin composition, adhesive film, dicing die bonding film, semiconductor wafer and semiconductor device according to the present invention are particularly explained in turn.

[17]

[18] Adhesive Resin Composition

[19] An adhesive resin composition according to the present invention comprises;

[20] a) a multi-functional epoxy resin;

[21] b) a phenol resin, of which a moisture absorptivity is 2.0 % by weight or less as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours; and

[22] c) a thermoplastic resin.

[23]

[24] Each component of the present resin composition is explained in detail below.

[25] The a) multi-functional epoxy resin used in the present invention is not particularly restricted, as long as it is cured to represent adhesion property. Examples of the a) multi-functional epoxy resin used in the present invention may include an epoxy resin having 3 or more functional groups, preferably, an epoxy resin having an average epoxy equivalent of 180 to 1,000, more preferably, a cresol novolac epoxy resin, a bisphenol A type novolac epoxy resin, a phenol novolac epoxy resin, a 4-functional epoxy resin, a biphenyl type epoxy resin, a triphenol methane type epoxy resin, an alkyl modified triphenol methane type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin or a dicyclopentadiene modified phenol type epoxy resin alone or in a mixture of two or more resins above. If an average epoxy equivalent of said multi-functional epoxy resin a) herein is less than 180, it is apprehended that its cross-linking density after curing is highly increased to represent hardening property. Also, if said average epoxy equivalent is in excess of 1,000, it is apprehended that its glass transition temperature (Tg) is lowered.

[26]

[27] In terms of moisture resistance at high temperature, the present invention uses b) a phenol resin, of which a moisture absorptivity is 2.0 % by weight or less as treated by Pressure Cooker Test (PCT), particularly in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours. In addition, when a film is prepared by using said b) phenol resin, it is preferred that the moisture absorptivity of film is 1.5 by weight or less.

[28] When said b) phenol resin herein is also measured by thermogravimetric analysis

(TGA), it is preferred that its weight decrement is less than 10 % by weight as heated from 5O ⁰ C to 26O ⁰ C at a rate of 10°C/min under nitrogen atmosphere. If the phenol resin has a weight decrement of the above range, the amount of volatile components is slight in the process and thus reliability such as heat resistance or moisture resistance may be improved.

[29]

[30] In terms of flowability, the viscosity of said b) phenol resin herein is preferably 200 cps or less as measured at 15O ⁰ C. If the phenol resin having the viscosity of the above range is used, it may be favorably maintain the flowability during the process to have

improved filling property. In addition, since it has excellent moisture resistance at high temperature, the reliability of semiconductor package may be improved. The lower limit of said viscosity is not particularly restricted, but preferably 80 cps.

[31] [32] In terms of heat resistance, a multi-functional phenol resin having 3 or more functional phenolic hydroxyl groups, preferably a phenol resin having an average hydroxyl equivalent of 100 to 500 herein is used as said b) phenol resin. If said average hydroxyl equivalent is less than 100, it is apprehended that the hardener has low hardness and the bond strength is lowered. If said equivalent is in excess of 500, it is apprehended that the glass transition temperature (Tg) is lowered and the heat resistance is deteriorated.

[33] [34] More preferred examples of phenol resin used in the present invention may include a resin represented by Ibrmula 1 below.

[35] [Ibrmula 1]

[37] (wherein, n is an integer of 0 to 50). [38] [39] Preferred examples of phenol resins represented by Ibrmula 1 above may include di- cyclopentadiene phenol novolacs ("DPP," below), and among these, preferably one or more selected from the group consisting of DPP-6085, DPP-6095 and DPP-6115

[40] [41] It is preferred that the amount of said phenol resin in the adhesive resin composition of the present invention is 0.5 to 1.2 equivalents or so, based on an equivalent ratio, relative to epoxy resin. Based on a weight ratio, it is preferred for the phenol resin to be included in a range of 60 to 150 parts by weight relative to 100 parts by weight of said epoxy resin. If the amount of said phenol resin is less than 60 parts by weight, unreacted epoxy groups are remained and the glass transition temperature (Tg) is lowered. Then, since the remained epoxy groups are volatilized on testing high temperature reliability, it is apprehended that the reliability of semiconductor package

is lowered. In aάϊtion, if the amount of said phenol resin is in excess of 130 parts by weight, it is apprehended that although the cross-link density is increased, the moisture absorptivity is increased or the storage stability is deteriorated, due to unreacted hydroxy (OH) groups.

[42]

[43] In the thermoplastic resin used herein, it is preferred that the glass transition temperature (Tg) is -60 to 3O ⁰ C and the weight average molecular weight is 100,000 to 1,000,000, in terms of bond strength and heat resistance. By induing such a thermoplastic resin, the flowability may be controlled on molding a film, and the elasticity modulus may be decreased to secure the flexibility of the finished film. If said glass transition temperature (Tg) is less than -6O ⁰ C, it is apprehended that since the bond strength is highly increased, handling ability and workability are rather lowered. If it is in excess of 3O ⁰ C, it is apprehended that the bond strength at low temperature is lowered. If the weight average molecular weight of the thermoplastic resin used herein is less than 100,000, it is apprehended that since the flexibility or strength of the adhesive film is lowered, the handling ability is deteriorated, and that since streams are increased on filling circuit of a substrate for semiconductor, the flowability cannot be controlled. In aάϊtion, if said weight average molecular weight is in excess of 1,000,000, it is apprehended that since the effect of controlling the flowability on die bonding is increased and thus, when unevenness is present on the surface of substrate, the filling property is lowered, the reliability and the circuit filling property of the adhesive film are reduced.

[44]

[45] The thermoplastic resin used herein may be appropriately selected by any technician skilled in the field to which this invention is pertained. Without being specifically limited, it is preferably one or more selected from polyimide, polyetherimide, polyesterimide, polyamide, polyethersulfone, polyetherketone, polyolefin, polyvinyl chloride, phenoxy, reactable butadiene acrylonitrile copolymer rubber and an acrylic resin, and more preferably, an acrylic resin.

[46]

[47] It is preferred that said acrylic resin is an acrylic copolymer comprising an acrylic acid and its derivative. Examples of said acrylic acid and its derivative may include acrylic acid; methacrylic acid; alkyl acrylate ester having 1 to 12 carbon atoms such as methyl acrylate or ethyl acrylate; alkyl methacrylate ester having 1 to 12 carbon atoms such as methyl methacrylate or ethyl methacrylate; a monomer such as acrylonitrile or

acrylamide and other copolymerizable monomers. In aάϊtion, it is preferred that said acrylic copolymer comprises one or more functional groups selected from the group consisting of a glycidyl group, a hydroxy group, a carboxyl group and a nitrile group. Preferred examples of a monomer having such a functional group may include glycidyl (meth)acrylate as a case having a glycidyl group; hydroxy (meth)acrylate or hydroxy ethyl (meth)acrylate as a case having a hydroxy group; or carboxyl (meth)acrylate as a case having a carboxyl group, and the like.

[48]

[49] The amount of the functional group in said acrylic copolymer is not particularly limited, but preferably in a range of 0.5 to 10 parts by weight relative to 100 parts by weight of the acrylic resin. If said amount of functional group is less than 0.5 parts by weight, it is hard to secure the bond strength. Also, if it is in excess of 10 parts by weight, the bond strength is so strong that the workability is lowered, and thus, there is a drawback that gelation cannot be prevented.

[50]

[51] The thermoplastic resin included in the adhesive resin composition according to the present invention, is preferably included in a range of 100 to 400 parts by weight, relative to 100 parts by weight of the epoxy resin. If the amount of said thermoplastic resin is less than 100 parts by weight, the elasticity modulus is so high that the resin composition is not easily molded in a shape of film in the preparing processes, and streams tend to increase on molding. If it is in excess of 400 parts by weight, the effect of inhibiting streams is so high that the filling property is lowered, and the handling ability at high temperature tends to deteriorate.

[52]

[53] A preparation process for said thermoplastic resin may be appropriately selected by technicians skilled in this field of invention. Without being particularly limited, a process such as solution polymerization, emulsion polymerization or suspension polymerization, for example, may be used.

[54] In the adhesive resin composition according to the present invention, a coupling agent may be further comprised. Said coupling agent may be included in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 10 parts by weight, relative to 100 parts by weight of all resin components. Close adhesion of a semiconductor wafer or silica filler with an interface herein may be improved by induing said coupling agent. In aάϊtion, the adhesive property and the close adhesion may be improved by reacting organic functional groups in the coupling agent with the resin components on the

curing reaction, without impairing heat resistance of hardener, and thus, the moisture- heat resistance is also improved. If said coupling agent is included in an amount of less than 0.01 parts by weight, the close adhesion effect of adhesive film is insufficient. If it is included in an amount of more than 10 parts by weight, it is apprehended that voids are caused or the heat resistance is lowered due to the unreacted coupling agent.

[55]

[56] The usable coupling agent herein is not particularly limited, as long as it exhibits the above mentioned effects, but preferably a silane coupling agent, a titanate coupling agent, an aluminate coupling agent or combinations of two or more coupling agents above, and more preferably a silane coupling agent, in that the effect to cost is high. Preferred examples of said silane coupling agent are one or more selected from amino silane, epoxy silane, mercapto silane, ureido silane, methacryloxy silane, vinyl silane, glycidoxy silane and sulfido silane.

[57]

[58] Preferred examples of said amino silane may include, but are not limited to, N- β(aminoethyl)-γaminopropyl trimethoxysilane, N-β(aminoethyl)-γ aminopropylmethyl dimethoxysilane, γaminopropyl triethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl-tris(2-methoxy-ethoxy-ethoxy)silane, N-methyl-3-aminopropyl trimethoxysilane, triaminopropyl-trimethoxysilane, or N- phenyl-γ aminopropyl trimethoxysilane; preferred examples of said epoxy silane may include, but are not limited to, β(3,4-epoxycyclohexyl)ethyltrimethoxysilane; preferred examples of said mercapto silane may include, but are not limited to, γmercaptopropyl trimethoxysilane, 3-mercaptopropyl-methyldimethoxysilane, or γmercaptopropyl triethoxysilane; preferred examples of said ureido silane may include, but are not limited to, 3-ureidopropyl triethoxysilane, or 3-ureidopropyl trimethoxysilane; preferred examples of said methacryloxy silane may include, but are not limited to, γmethacrylo xypropyl trimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, or γmethacryloxypropylmethyl dimethoxysilane; preferred examples of said vinyl silane may include, but are not limited to, vinylmethyldimethoxysilane, vinyltrichlorosilane, vinyltris( βmethoxyethoxy)silane, vinyltriethoxysilane, or vinyltrimethoxysilane, and the like; preferred examples of said glycidoxy silane may include, but are not limited to, γglycidoxypropyl trimethoxysilane, γglycidoxypropylmethyl dimethoxysilane, or γglycidoxypropylmethyl diethoxysilane.

[59]

[60] The adhesive resin composition according to the present invention may further comprise 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, of a hardening accelerator relative to 100 parts by weight of the epoxy resin, and the hardening reaction of the resin composition may be accelerated by comprising said hardening accelerator. If the amount of said hardening accelerator is less than 0.1 parts by weight, the cross-linking of the epoxy resin is so insufficient that the heat resistance tends to reduce. If it is in excess of 10 parts by weight, it is apprehended that the hardening reaction is promptly performed, and thus the storage stability is lowered.

[61]

[62] The usable hardening accelerator herein is not particularly limited, as long as it is usually used in the technical field of the present invention, but one or more selected from an imidazole compound, triphenylphosphine (TTP) and a tertiary amine may be used. Preferably, an imidazole compound is used. Preferred examples of said imidazole compound may include, but are not limited to, one or more selected from the group consisting of 2-methyl imidazole (2MZ), 2-ethyl-4-methyl imidazole (2E4MZ), 2-phenyl imidazole (2PZ), l-cyanoethyl-2-phenyl imidazole (2PZ-CN), 2-undecyl imidazole (CI lZ), 2-heptadecyl imidazole (C 17Z) and l-cyanoethyl-2-phenyl imidazole trimellitate (2PZ-CNS).

[63]

[64] In terms of improved handling ability and heat resistance and control of melt viscosity, the present resin composition may further comprise 5 to 100 parts by weight of filler, relative to 100 parts by weight of the solid resin. If the amount of said filler is less than 5 parts by weight, it is apprehended that the effect of improving heat resistance and handling ability by aάϊng the filler is insufficient. If it is in excess of 100 parts by weight, it is apprehended that the effect of improving handling ability and close adhesion is lowered.

[65]

[66] Kinds of said filler may include organic fillers or inorganic fillers, and preferably, in the characteristic side, inorganic fillers. Said inorganic filler may include one or more selected from silica, talc, aluminum hydroxide, calcium carbonate, magnesium hydroxide, alumina, and aluminum nitride. Spherical silica is more preferred, in that it has good dispersibility in the resin composition and uniform bond strength in the film.

[67]

[68] The average particle diameter of said filler is not particularly limited, but preferably,

10 to 1,000 nm. If said particle diameter is less than 10 nm, it is apprehended that the filler is easily cohered in the adhesive film and appearance defects are caused. If it is in excess of 1,000 nm, it is apprehended that the filler in the adhesive film protrudes onto the surface of the film, and on hot pressing the film on the wafer, chips are damaged or the effect of improving adhesive property is lowered.

[69]

[70] Adhesive Him

[71] The present invention also relates to an adhesive film comprising

[72] a base film; and

[73] an adhesive layer, which is formed on said base film and comprises an adhesive resin composition according to the present invention. The present adhesive film comprises an adhesive resin composition according to the present invention, wherein said composition comprises b) a phenol resin, so that it has excellent bond strength and filling property in a semi-hardening state, and it uses c) a thermoplastic resin and a filler, so that it has excellent heat resistance, hygroscopic resistance and reflow crack resistance, and the like.

[74]

[75] The adhesive film according to the present invention is explained below, with reference to Hg. 1.

[76] As the base film (10) of the adhesive film according to the present invention, a plastic film such as a polyethyleneterephthalate film, a polytetrafluoroethylene film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a vinylchloride copolymer film or a polyimide film may be used. In aάϊtion, it is preferred to treat release coating on a surface of said base film. The release agent used in release coating of surfaces may include alkyd-, silicone-, fluoride-, unsaturated ester-, polyolefin- or wax-based release agents, and most preferably, alkyd-, silicone- or fluoride -based release agents, in that they have heat resistance.

[77]

[78] The thickness of the base film is preferably 10 to 500 μm, and more preferably 20 to

200 μm. If said thickness is less than 10 μm, much elongation is caused on coating the film on a substrate and curing it. If it is in excess of 500 μm, it is not economical.

[79]

[80] The adhesive layer (20) of said adhesive film comprises an adhesive resin composition according to the present invention, and thus can minimize for voids to be generated when said adhesive film is adhered to a semiconductor wafer at low

temperature, and maintain high bond strength with the wafer to prevent scattering chips in the dicing process. [81] [82] The thickness of said adhesive layer is not particularly limited, but the thickness of the hot cured adhesive layer is preferably 5 to 200 μm, and more preferably 10 to 100 μm. If the thickness is less than 5 μm, the effect of relaxing stress at high temperature is impaired. If it is in excess of 200 μm, it is not economical. [83] [84] In aάϊtion, said adhesive layer (20) may be formed on one side of the base film (10) to form two layered structure of a base film/an adhesive layer or three layered structure of an adhesive layer/a base film/an adhesive layer or a base film/an adhesive layer/a base film. [85] [86] The present invention also relates to a preparation process for an adhesive film of the present invention.

[87] Said preparation process for the adhesive film is characterized by comprising

[88] a first step of preparing a resin varnish by dissolving or dispersing an adhesive resin composition in a solvent;

[89] a second step of applying said resin varnish on a base film; and

[90] a third step of removing the solvent by heating the base film applied with said resin varnish. [91] [92] The first step of said process according to the present invention is a step which prepares a resin varnish by using an adhesive resin composition according to the present invention. [93] [94] As said solvent for varnish, methylethyl ketone (MEK), acetone, toluene, dimethyl- formamide (DMF), methylcellosolve (MCS), tetrahydrofuran (THF), N- methylpyrrolidone (NMP) or combinations of two or more solvents above, and the like, may be usually used. Considering heat resistance of the base film, it is preferred to use a solvent having low boiling point. But, in order to improve film performance, a solvent having high boiling point may be also used. [95] [96] In aάϊtion, in order to shorten process time or obtain good dispersibility in the adhesive film, filler may be also used in said first step. When the filler is used, said

first step may comprise;

[97] (a) a step of mixing a solvent, a filler and a coupling agent;

[98] (b) a step of aάϊng an epoxy resin and a phenol resin to the mixture of said step (a) and mixing them; and

[99] (c) a step of mixing a thermoplastic resin and a hardening accelerator with the mixture of said step (b).

[100]

[101] Examples of said filler may include Ball Mill, Bead Mill, three rolls or high speed disperser alone or combinations of two or more of the forgoing. Balls or beads are made from glass, alumina or zirconium, and the like. In the dispersibility side of particles, the balls or beads made from zirconium are preferred.

[102]

[103] The second step in the preparation process for an adhesive film according to the present invention is a step which applies said resin varnish on the base film.

[104]

[105] A method of applying the resin varnish on said base film is not particularly limited. Usual methods in the technical field of the present invention may be used. Ibr example, knife coat method, roll coat method, spray coat method, gravure coat method, curtain coat method, comma coat method or lip coat method, and the like may be used.

[106]

[107] The third step in the preparation process for an adhesive film according to the present invention is a step which removes the solvent by heating the base film applied with said resin varnish. At this time, heating is preferably performed at 70 to 25O ⁰ C for about 5 to 20 minutes. The thickness of heat cured adhesive layer after applying the varnish is preferably 5 to 200 μm and more preferably 10 to 100 μm.

[108]

[109] Dicing Die Bonding Him

[110] The present invention also relates to a dicing die bonding film comprising

[111] a dicing tape; and

[112] said adhesive film according to the present invention which is laminated on said dicing tape.

[113]

[114] The dicing die bonding film according to the present invention is explained below, with reference to Hg. 2.

[115] Preferably, said dicing tape comprises

[116] a base film (40); and

[117] a pressure-sensitive adhesive layer (30) which is formed on said base film.

[118]

[119] As the base film (40) of the dicing tape, a polyethylene film, a polypropylene film, a polytetrafluoroethylene film, a polyethyleneterephthalate film, a polyurethane film, an ethylene vinyl acetone film, an ethylene-propylene copolymer film, an ethylene- acrylic acid ethyl copolymer film or an ethylene- acrylic acid methyl copolymer film, and the like may be used. If necessary, surface treatment such as primer application, corona treatment, etching treatment or UV treatment is preferably performed. When the pressure-sensitive adhesive is cured with UV irradiation, it may be also selected from one having good optical transparency.

[120]

[121] The thickness of said base film of dicing tape is not particularly limited. But, considering handling ability or packaging process, it is preferably 60 to 160 μm, and more preferably 80 to 120 μm.

[122]

[123] As the pressure-sensitive adhesive layer (30) of the dicing tape, usual ultraviolet curing pressure-sensitive adhesive or thermally curing pressure-sensitive adhesive may be used. In case of the ultraviolet curing pressure-sensitive adhesive, the adhesion strength is lowered by irradiating it from the side of the base film with ultraviolet to increase its cohesive attraction. In case of the thermally curing pressure-sensitive adhesive, the adhesion strength is lowered by heating.

[124]

[125] A preparation process for a dicing die bonding film according to the present invention may include a method of hot roll laminating a dicing tape and an adhesive film and a method of laminate pressing them, and the like. The hot roll laminating method is preferred in view of capability of continuous processes and efficiency. In aάϊtion, it is preferred that the hot roll lamination is performed in a condition under a

2 pressure of 0.1 to 10 Kgf/cm at the temperature of 10 to 100 ⁰ C.

[126]

[127] When the dicing die bonding film according to the present invention is adhered to a semiconductor wafer to dice it, it has excellent bond strength to prevent scattering chips, and the adhesive film is easily peeled on pick-up, and thus it has excellent filling property on bonding chips to a semiconductor substrate. Therefore, the semi-

conductor package can be provided with excellent package reliability.

[128]

[129] Semiconductor Wafer

[130] The present invention also relates to a semiconductor wafer, wherein the adhesive film of the dicing die bonding film according to the present invention is adhered to one side of the wafer, and the dicing tape of said dicing die bonding film is fixed on a wafer ring frame.

[131]

[132] Such a semiconductor wafer may be prepared, by bonding the adhesive film of the dicing die bonding film to the back side of the semiconductor wafer in a condition such as a laminate temperature of 0 to 18O ⁰ C and fixing the dicing tape of said dicing die bonding film on the wafer ring frame.

[133]

[134] Semiconductor Device

[135] In acϋtion, the present invention relates to a semiconductor device comprising

[136] a wiring substrate (50);

[137] an adhesive layer (20), including an adhesive composition according to the present invention, which is adhered to the chip loading side of said wiring substrate; and

[138] a semiconductor chip (1) mounted on said adhesive layer.

[139]

[140] A preparation process for said semiconductor device is explained as follows.

[141] The semiconductor wafer to which the previously described dicing die bonding film is adhered is completely cut using a dicing apparatus to divide into individual chips.

[142] Then, when the dicing tape is a ultraviolet curing pressure-sensitive adhesive, it is cured by irradiating it from the side of the base film with ultraviolet. When it is a thermally curing pressure-sensitive adhesive, it is cured by rising temperature. In the cured pressure-sensitive adhesive with ultraviolet or heat as above, close adhesion strength of the adhesive is lowered, and thus pick-up of chips is easily performed in subsequent processes. At this time, if necessary, the dicing die bonding film may be expanded. If such an expanding process is practiced, the interval between chips is expanded, so that pick-up is easily performed, and the creep between the adhesive layer and the pressure-sensitive adhesive layer is generated to improve the pick up property.

[143] Continuously, chip pick up is practiced. Then, the semiconductor wafer and the pressures-sensitive adhesive layer of dicing die bonding film may be peeled from the

adhesive layer of dicing die bonding film to obtain chips that the adhesive layer only is adhered thereto. The obtained chip, to which said adhesive layer is adhered, is adhered to a substrate for semiconductor. The adhering temperature of the chip is usually 100 to 18O ⁰ C, the adhering time is 0.5 to 3 seconds, and the adhering pressure is 0.5 to 2 Kgf/cm ² .

[144] Ibllowing proceeding said process, the semiconductor device is obtained through wire bonding and molding processes.

[145] The preparation process for the semiconductor device is not limited to the above procedure, but may also comprises any step and change the order of procedure. R>r example, it may also proceed by ultraviolet curing dicing - expanding processes, or dicing expanding - ultraviolet curing processes. Ibllowing the chip adhering process, a heating or cooling process may be further comprised.

[146]

Mode for the Invention

[147] Hereinafter, the present invention is explained in more detail through examples according to the present invention and comparative examples not according to the present invention. However, the scope of the present invention is not restricted to the represented examples below.

[148]

[149] Example 1

[150] Preparation of Acrylic Resin

[151] To a 4-neck 3L reactor provided with a stirrer, a nitrogen replacement apparatus and a thermometer, 150 g of butyl acrylate, 200 g of ethyl aery late, 140 g of acrylonitrile, 16 g of glycidyl methacrylate and 1,500 g of deionized distilled water were added. 4 g of 4% polyvinyl alcohol diluted in water (trade name: NH- 17, manufactured by Nippon Ghosei) as a suspending agent and 0.3 g of dcdecyl mercaptan as a molecular weight regulator were added hereto to prepare a mixture. Nitrogen replacement was performed in the mixture for about 1 hour, and the temperature was increased to 55 ⁰ C. On reaching the set temperature, 4 g of diethylhexyl peroxy dicarbonate (trade name: Trigonox EHP, manufactured by Akzo Nobel) diluted into 2% by ethyl acetate as an initiator was added to initiate the polymerization reaction. The reaction was ended 4 hours after initiating it. The reactant was washed several times with deionized distilled water, and then dried using a centrifuge and a vacuum oven to obtain polymer beads. The yield was 90%, the molecular weight(M ) as measured by gel permeation chromatography was 700,000, molecular weight distribution was 3.0

and the glass transition temperature (Tg) as measured by DSC (Differential Scanning Calorimeter) was 5 ⁰ C. The obtained polymer beads were dissolved in methyl ethyl ketone and used in coating.

[152]

[153] Preparation of Adhesive Resin Composition. Adhesive Elm and Dicing Die Bonding Him

[154] 100 parts by weight of cresol novolac epoxy resin (EOCN- 1020-55, manufactured by Nippon Kayaku Co., Ltd.; epoxy equivalent: 199, softening point: 55 ⁰ C) as an epoxy resin, 90 parts by weight of DPP-6115 (manufactured by Kolong Industries, Inc.; hydroxy equivalent: 180, softening point: 115 ⁰ C, moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours: 1.0 % by weight) as a phenol resin, 150 parts by weight of the thermoplastic resin prepared by the above method, 0.5 parts by weight of 2-phenyl-4-methyl-5-dihydroxymethyl imidazole (2P4MHZ, manufactured by Shikoku Chemicals Corporation) as a hardening accelerator, 2 parts by weight of -glycidoxy propyl trimethoxy silane (KBM-403, manufactured by Shin-Etsu Chemical) as a coupling agent and 30 parts by weight of UFP-80 (DENKA, Spherical Silica, Average Particle Diameter: 75 nm) as a filler were added to methyl ethyl ketone, stirred and mixed to prepare a varnish.

[155]

[156] Said varnish was applied on a base film having a thickness of 38 μm (Release

Polyester Elm, RS-21G, manufactured by SKC), and dried at 16O ⁰ C for 3 minutes to prepare an adhesive film having a film thickness of 20 μm. Then, using a laminator (manufactured by Fujishoko), said adhesive film was laminated to a dicing tape (SLIONTEC 6360-50) under 5 Kgf/cm ² at 3O ⁰ C to obtain a dicing die bonding film.

[157]

[158] Example 2

[159] A film was prepared in the same manner as Example 1 except that 100 parts by weight of dicyclopentadiene modified epoxy resin (XD-IOOOL, manufactured by Nippon Kayaku Co., Ltd.; epoxy equivalent: 253, softening point: 74 ⁰ C) as an epoxy resin and 70 parts by weight of DPP-6115 as a phenol resin were used.

[160]

[161] Example 3

[162] A film was prepared in the same manner as Example 1 except that 100 parts by weight of naphthol novolac epoxy resin (NC-7300L, manufactured by Nippon Kayaku Co., Ltd.; epoxy equivalent: 215, softening point: 62 ⁰ C) as an epoxy resin and 85 parts

by weight of DPP-6115 as a phenol resin were used.

[163]

[164] Example 4

[165] A film was prepared in the same manner as Example 1 except that 85 parts by weight of DPP-6085 (manufactured by Kolong Industries, Inc.; hydroxy equivalent: 168, softening point: 87 ⁰ C, moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours: 1.5 % by weight) as a phenol resin was used.

[166]

[167] Comparative Example 1

[168] A film was prepared in the same manner as Example 1 except that 100 parts by weight of bisphenol A epoxy resin (YD- 128, manufactured by Kukfo Chemical Co., Ltd.; epoxy equivalent: 187) as an epoxy resin and 100 parts by weight of DPP-6115 as a phenol resin were used.

[169]

[170] Comparative Example 2

[171] A film was prepared in the same manner as Example 1 except that 50 parts by weight of phenol novolac resin (KPH-F2001, manufactured by Kolong Industries, Inc.; hydroxy equivalent: 106, softening point: 84 ⁰ C, moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours: 4.5 % by weight) as a phenol resin was used.

[172]

[173] Comparative Example 3

[174] A film was prepared in the same manner as Example 1 except that 60 parts by weight of bisphenol A novolac resin (Phenolite VH-4170, manufactured by Kangnam Chemical Co., Ltd.; hydroxy equivalent: 118, softening point: 105 ⁰ C, moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours: 52 % by weight) as a phenol resin was used.

[175]

[176] Comparative Example 4

[177] A film was prepared in the same manner as Example 1 except that 90 parts by weight of Xylok resin (KPH-F3075, manufactured by Kolong Industries, Inc.; hydroxy equivalent: 175, softening point: 75 ⁰ C, moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours: 3.2 % by weight) as a phenol resin was used.

[178]

[179] Compositions of said examples and comparative examples and moisture ab- sorptivities and weight decrements of phenol resins used in the above each are represented in Tables 1 and 2 below. [180] Table 1

[Table 1]

[Table ]

[181] (Ex.: Example; C. Ex.: Comparative Example) [182] Table 2

[Table 2] [Table ]

[183] * Moisture absorptivity as treated in a condition of 121 ⁰ C, 2 atms and 100% RH for 48 hours [184] ** Weight decrement as heated from 5O ⁰ C to 26O ⁰ C at a rate of 10°C/min under nitrogen atmosphere

[185] [186] Regarding the Examples 1 to 4 and the Comparative Examples 1 to 4, their physical properties were measured by the following methods and their results were represented in Table 3.

[187] [188] [Evaluation Method of Him] [189] (1) Bond Strength [190] An 8 -inch silicon wafer was laminated with a die bonding film in a tape mounter (Hugle Electronics Inc.) set at 6O ⁰ C for 10 seconds. Using TA.XT Plus Texture Analyzer (Stable Micro Systems Ltd.), the bond strength for the above die bonding film was measured in a condition such as a peeling speed of 5 mm/s and a peeling angle of 180 .

[191] [192] (2) Riling Property [193] A PCB having a height difference of 10 μm was used as a substrate. A die bonding film (20 μm) was cut by 25 mm 25 mm, and laminated with a chip in a tape mounter (Hugle Electronics Inc.), at 6O ⁰ C. The chip, to which the PCB and the die bonding were adhered, was pressed under a pressure of 1.5 Kg at 13O ⁰ C for 1 second. By calculating the amount that the film flowed and poured into pattern gaps of PCB, the filling ratio was calculated. Evaluation manner of the filling property was represented below.

[194]

[195] ®: Riling Ratio: more than 60%

[196] O: Riling Ratio: 30 ~ 60%

[197] X : Riling Ratio: less than 30%

[198]

[199] (3) Moisture Absorptivity of RIm

[200] The weight (A) of the film cured in an oven at 19O ⁰ C for 2 hours was measured, and after treating said film in a condition of 121°C/100% RH/2 atms for 48 hours, using a PCT Equipment (Hirayama Manufacturing Corporation), and removing moisture on its surface, its weight (B) was measured. The above measured values were substituted for the following equation (1) to calculate the moisture absorptivity.

[201]

[202] Equation (1) -- Moisture Absorptivity (% by weight) = ([B-A] X 100)/A

[203]

[204] (4) Moisture Resistance

[205] After treating the film adhered with a wafer in a condition of 121 ⁰ C, 100% RH and 2 atms for 72 hours, using a PCT Equipment, it was observed whether or not peeling was caused. Evaluation manner was represented below.

[206] O: peeling was not caused

[207] X : peeling was caused

[208]

[209] (5) IR Reflow Test

[210] A chip and a PCB were adhered to a die bonding film, and they were cured at 18O ⁰ C for 2 hours to prepare a semiconductor package sample. The sample was left at -65 ⁰ C for 15 minutes and then at an atmosphere of 15O ⁰ C for 15 minutes, using a thermal shock tester (DIMOS TECH Co., Ltd.), and this step was repeated 5 times. Then, it was left in a temperature and humidity chamber of 85 ⁰ C and 85% for 72 hours, passed through an IR Reflow Apparatus that the highest temperature of sample surface was set to be maintained at 26O ⁰ C for 30 seconds, left at room temperature and cooled, and this treatment was repeated 3 times. Then, cracks of the above sample were observed by an ultrasonic microscope (SAT). Evaluation manner was represented below.

[211] O: Peeling or crack, and the like was not caused

[212] X : Peeling or crack, and the like was caused

[213] Table 3

[Table 3] [Table ]

[214] [215] As shown in Table 2 above, it could be confirmed that the adhesive films of Examples 1 to 4 prepared in accordance with the present invention had excellent physical properties in the semi-curing state and the cured state, compared with those of Comparative Examples 1 to 4.

[216] [217] In aάϊtion, in the films using the phenol resins included in Ibrmula 1 of the present invention, the bond strength and the filling property had a slight difference, depending on kinds of epoxy resins, but it showed such a level that any problem was not caused in performing the processes. Thus, excellent results could be confirmed in moisture resistance and reflow resistance, due to low moisture absorptivity. On the other hand, in case of Comparative Example 1 using a two-functional epoxy resin rather than a multi-functional epoxy resin, the bond strength and the filling property was secured to a certain extent, but it could be confirmed that there was a problem in the reliability side, due to low heat resistance. It could be also confirmed that there was a problem in Comparative Examples 2 and 3 using phenol resins having high moisture absorptivity. In case of Comparative Example 4 using the phenol resin having low weight decrement but high moisture absorptivity, it had good reflow resistance, but

there was a problem in the moisture resistance side. Industrial Applicability The adhesive film for semiconductor according to the present invention has excellent bond strength with a wafer and filling property in a semi-curing state, so that the process fraction defective may be reduced. After producing semiconductor package in the cured state, it has excellent heat resistance, hygroscopic resistance or reflow crack resistance, and the like, so that semiconductor devices having excellent reliability may be prepared.