KR101475139B1 - Mask sheet for manufacturing semiconductor device and manufacturing method of semiconductor device using the same - Google Patents

Abstract

As a mask sheet, taping on L / F at a temperature lower than that of a thermoplastic mask sheet does not cause thermal deterioration such as occurrence of adhesive residue upon peeling of the mask sheet even when exposed to a high temperature, There is a demand for a mask sheet which is harder than a mask sheet and has excellent W / B properties, less leakage of molding resin during sealing than a pressure-sensitive adhesive mask sheet, and excellent light fastness even after a plasma cleaning process.
The present invention relates to a mask sheet for manufacturing a semiconductor device in which a thermosetting adhesive layer is laminated on one surface of a substrate layer and is adhered to a metal plate so as to be releasable, wherein the thermosetting adhesive layer contains a siloxane skeleton having a glass transition temperature of 45 to 170 deg. A polyimide resin, an epoxy resin, a curing agent, and a fluorine additive.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mask sheet for manufacturing a semiconductor device and a method of manufacturing a semiconductor device using the same. 2. Description of the Related Art Mask Sheet for Manufacturing Semiconductor Device and Method for Manufacturing Semiconductor Device Using the Same

The present invention relates to a mask sheet for manufacturing a semiconductor device (hereinafter, referred to as a mask sheet) used for masking a lead frame from a molding resin when a semiconductor device is molded (resin encapsulated) by mounting a semiconductor chip on a lead frame, And a manufacturing method of a semiconductor device using a mask sheet which is formed by laminating a metal plate on a metal plate to form a metal plate in a predetermined pattern, mounting the semiconductor chip on the metal plate, molding and removing the metal plate.

Nowadays, portable PCs and mobile phones are becoming popular, there is a demand for more compact, thinner, and multifunctional electronic devices. In order to realize such a demand, miniaturization and high integration of electronic components are also essential, but high-density mounting technology of higher electronic components is required. Density packaged IC package called a CSP (Chip Size Package) instead of a peripheral mounting type such as a conventional QFP (Quad Flat Package) and an SOP (Small Outline Package). Among them, a package called QFN (Quad Flat Non-lead) can be manufactured by a conventional lead frame (hereinafter also referred to as L / F), wire bonding (hereinafter also referred to as W / B) So that it has mainly been used in the manufacture of a small terminal type package of 100 pins or less and has been increasingly applied to a multi-pin package. These QFNs are produced as follows. That is, a mask sheet is adhered to one surface of a lead frame, a semiconductor chip is mounted on the opposite surface, and a lead is connected to a chip by a gold wire. Then, after the molding, the mask sheet is peeled off and finally each piece is fragmented (individualized). Recently, as the use thereof has been expanded, recently, gold wires have become copper wires and become copper wires coated with palladium (Pd) or the like, and various problems have appeared in mask sheets that have been conventionally applied.

Up to now, a highly crosslinked silicone adhesive to a resin layer, or a rubber sheet and an epoxy sheet have been exemplified as a mask sheet (see, for example, Patent Document 1). However, as a pressure-sensitive adhesive, a sufficient hardness can not be obtained even by highly crosslinking, and it is likely to be deformed by heat pressure, and W / B performed at a high temperature is not sufficiently obtained.

Further, in the case of an adhesive composed of rubber and epoxy, since the rubber is relatively soft, it is necessary to increase the content of epoxy in order to obtain rigidity at high temperature. As a result, the adhesiveness with the base layer is lowered, the cured product is hardened and the ductility is lowered, and the adhesive remains on the molding resin or the frame surface when the mask sheet is peeled off. Particularly, since the rubber material undergoes thermal decomposition even at a relatively low temperature, it is decomposed in a high-temperature process such as W / B and is likely to become an outgas to contaminate the frame. As to a mask sheet of a thermosetting adhesive using rubber, a mask sheet using bismaleimide and acrylonitrile butadiene resin is disclosed (for example, see Patent Document 2). Further, although the release properties of bismaleimide and acrylonitrile-butadiene resin are improved by silicone oil, the rubber component is thermally deteriorated when exposed to a high temperature and becomes hard and deteriorates in ductility, so that the resin tends to remain at the time of peeling (See, for example, Patent Document 3).

In view of this, a mask sheet using a polyimide resin instead of rubber has also been proposed. A polyimide resin was used to realize a mask sheet having less mold flash and excellent W / B (see, for example, Patent Document 4). However, the use of a polyimide resin having a glass transition temperature (hereinafter referred to as Tg) of 180 ° C or more and a polyimide resin having an elastic modulus of 150 MPa or more at 150 ° C or more is not preferable because the compression temperature is very high Deformation of the mask sheet due to the formation of the resin layer on only one side, such as a mask sheet made of a conventional thermoplastic resin, is high. Further, although components other than the polyimide resin can be appropriately blended, it is described that the adhesive layer contains polyimide resin in an amount of 60 mass% or more, so that the pressing temperature is high and further, no mention is made of the peeling of the mask sheet after molding none.

[Patent Document 1] Patent No. 4357754

[Patent Document 2] JP-A-2009-158817

[Patent Document 3] JP-A-2005-142401

[Patent Document 4] JP-A-2003-188334

Therefore, even when the mask sheet is subjected to L / F taping at a lower temperature than the thermoplastic mask sheet and exposed to a high temperature, the mask sheet does not generate thermal deterioration such as occurrence of adhesive residue upon peeling of the mask sheet, And is superior in W / B property, less leakage of molding resin during sealing than in the case of a pressure-sensitive mask sheet, and excellent in light-releasability even after a plasma cleaning process, Sheets are required.

As a result of efforts made to solve the above problems, the present inventors have completed the following inventions. That is, the mask sheet for manufacturing a semiconductor device of the present invention is a mask sheet for manufacturing a semiconductor device in which a thermosetting adhesive layer is laminated on one surface of a substrate layer and is adhered to a metal plate in a peelable manner, wherein the thermosetting adhesive layer has a glass transition temperature of 45 An epoxy resin, a curing agent, and a fluorine additive, the siloxane skeleton having a siloxane skeleton of?

In addition, in the melting viscosity curve of the thermosetting adhesive layer, it is preferable that the lowermost limit has a temperature of 70 to 200 占 폚, and the lowest viscosity has a viscosity of 4000 Pa 占 퐏 or more.

In the method of manufacturing a semiconductor device of the present invention, the thermosetting adhesive layer of the mask sheet for manufacturing a semiconductor device is laminated on a metal plate, the metal plate is formed into a predetermined pattern, the semiconductor chip is mounted, And removing the mask sheet for manufacturing the semiconductor device.

Since the mask sheet of the present invention has the above-described structure, it exhibits the following operational effects. L / F taping occurs at a lower temperature than the thermoplastic mask sheet. Even when exposed to a high temperature, thermal deterioration such as occurrence of residual adhesive at the time of delamination of the mask sheet is difficult to occur. It has flatness and small deformation. It is harder than the conventional pressure-sensitive adhesive mask sheet at high temperature and excellent in W / B property. This is a mask sheet having less leakage of molding resin during sealing than a pressure-sensitive adhesive mask sheet, and having excellent light fastness even after a plasma cleaning process, and having less adhesive residue.

Further, by using the mask sheet of the present invention, a semiconductor device can be efficiently manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a melt viscosity curve of an adhesive layer. Fig.
2 is a schematic plan view showing an example of a lead frame suitable for use in manufacturing a QFN using the mask sheet for manufacturing a semiconductor device of the present invention.
3 is a cross-sectional view taken along the line A-A 'in Fig. 2, showing an example of a manufacturing process of a QFN.

In the mask sheet of the present invention, the thermosetting adhesive layer (hereinafter, simply referred to as an adhesive layer) is melted by heating before being cured and can be pressed onto the metal sheet even at a high temperature as in thermoplastic. Further, after being cured by heat, it does not melt even when heated, and a high elastic modulus can be obtained at a higher temperature than the pressure-sensitive adhesive.

The thermosetting adhesive layer is a layer containing a polyimide resin. The polyimide resin has flexibility, rigidity and heat resistance as typified by a polyimide film. In the present invention, the polyimide resin is an essential material because the thermosetting adhesive requires flexibility in a semi-cured state and a cured state, and is required to have adhesiveness to a heat-resistant base layer.

The polyimide resin is a generic name of a polymer having an acid imide bond in the main chain and can be synthesized by condensation during cyclization of a tetracarboxylic anhydride and a diamine. As the polyimide resin, those having solubility or solubility in melt are suitable.

In the present invention, the polyimide resin is a polyimide resin having at least a structural unit represented by the formula (I), and a structural unit represented by the formula (II) and a structural unit represented by the formula (III)

(Wherein W represents a direct bond, an alkylene group having 1 to 4 carbon atoms, -O-, -SO ₂ - or -CO-, Ar ¹ represents a divalent group represented by the following formula (1) Represents an aromatic group

(Wherein X represents a direct bond, an alkylene group having 1 to 4 carbon atoms, -O-, -SO ₂ - or -CO-, Y represents an alkylene group having 1 to 4 carbon atoms, Z ¹ and Z ² Represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, Ar ² represents a divalent aromatic group having 1 or 2 hydroxyl or carboxyl groups, R ¹ and R ⁶ Represents an alkylene group having 1 to 4 carbon atoms or a group represented by the formula (3)

(Wherein Alk represents an alkylene group having 1 to 4 carbon atoms which is bonded to a silicon atom), R ² to R ⁵ represent an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 31.

Generally, the polyimide resin is rigid. In order to achieve flatness and taping at low temperature on the mask sheet before curing, which is the above problem, it is necessary to adjust Tg and hardness, and adjustment is made by introducing a siloxane skeleton. When the Tg is low, it is basically smooth and effective for flatness of the mask sheet, but tends to become insufficient from the standpoint of heat resistance, particularly hardness. However, since it is thermosetting and the heat resistance can be compensated by the curing component, the Tg may be 45 캜 or higher. In addition, a high Tg is effective from the viewpoint of hardness at high temperatures, but is not preferable from the viewpoint of the mask sheet flatness, and the taping temperature also becomes high. However, since the flatness and the taping temperature can be lowered by the curing component, the above problem can be solved if the temperature is 170 占 폚 or lower. That is, a polyimide resin having a Tg of 45 to 170 DEG C is suitable. Further, Tg is obtained by measuring the temperature at which the endothermic reaction occurs through differential thermal analysis, and from the peak, onset, and offset temperature.

In addition to the polysiloxane, the urethane skeleton and the diamine having a methylene chain can also be adjusted to Tg or hardness. Compared with polysiloxane, heat resistance tends to be lowered, thermal decomposition is easy, and molecular chains in an active atmosphere, such as a plasma treatment, tend to occur easily. In the case where a polar group or the like is generated and sealed on the surface after the plasma treatment, there is a possibility that adhesion to the molding resin is increased and the peeling force of the mask sheet is increased. Thus, there is a high possibility that the decomposed gas may contaminate the surroundings.

Siloxane is also effective from the viewpoint of peelability. However, since the siloxane moiety is introduced to adjust the hardness, it is necessary to take W / B into account and it is necessary to have adhesiveness with the substrate layer as the resin. As a result, the content and the degree of polymerization of the siloxane moiety are limited, and polysiloxane has an average degree of polymerization Is 2 to 33 (molecular weight is about 250 to 3000), preferably an average degree of polymerization of 4 to 24 (molecular weight is about 400 to 2000).

The molecular weight of the polyimide resin is preferably about 15,000 to 70,000 in consideration of solubility. The molecular weight can be measured by GPC using tetrahydrofuran (THF) as an eluent, and the average molecular weight in terms of styrene can be obtained. When the number average molecular weight is less than 15,000, the toughness and ductility of the film are impaired and the film is backed off. On the other hand, if it is larger than 70000, the meltability of the solvent is lowered, the workability is lowered, the melting property as an adhesive is lowered, and the taping temperature becomes higher and thus it is difficult to put it into practical use.

A reactive polyimide having a functional group can be obtained by reacting a tetracarboxylic acid dianhydride represented by the following formula (IV), a siloxane compound represented by the following formula (V) Can be obtained by imidizing a polyamic acid obtained by polycondensing a diamine compound represented by the following formula (VI) and a diamine compound having an epoxy reactive group represented by the following formula (VII) in an organic solvent by ring closure .

By having reactivity, W / B properties and the like are improved. In particular, when the W / B is carried out at a high temperature at a high temperature, the pressure-sensitive adhesive may be broken in the pressure-sensitive adhesive, but the adhesive layer in the present invention is not destroyed. Also, the mask sheet peelability is improved. When molding is carried out at a high temperature, the respective components of the adhesive are hardened to each other, and the adhesive property to the molding resin is not improved. As the functional group to be reacted, a carboxyl group, a hydroxyl group and the like are generally used.

The proportion of the polyimide resin in the adhesive is preferably 35 to 75% by mass. When the amount of the polyimide resin is less than 35 mass%, adhesion with the base material is lowered, and the resin remains at the time of peeling off the mask sheet, and more than 35 mass% is required from the viewpoint of flexibility. On the other hand, when the content exceeds 75% by mass, the meltability of the adhesive is lowered, and the temperature at which the adhesive is adhered increases, and problems such as the thermoplastic resin mask sheet are apt to occur.

The polyimide resin represented by the formula (I) used in the present invention will be described. The tetracarboxylic acid dianhydride represented by the following formula (IV) is reacted with a siloxane compound represented by the following formula (V), a diamine compound represented by the following formula (VI), or an epoxy reactive group represented by the following formula Can be obtained by imidizing a polyamic acid obtained by polycondensation of a diamine compound in an organic solvent by ring-closing.

(Wherein W, Ar ¹ , Ar ² , R ¹ to R ⁶ , n are as defined above.)

Examples of the tetracarboxylic acid dianhydride represented by the formula (IV) include 2,3,3 ', 4'-biphenyltetracarboxylic acid dianhydride, 3,4,3', 4'-biphenyl Tetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, 2,3,4'- , Bis (3,4-dicarboxyphenyl) sulfone anhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4,3 ', 4'-benzophenonetetracarboxylic dianhydride , 4 ', 4'-biphthalic acid dianhydride, and the like.

Examples of the siloxane compound having an amino group at both terminals represented by the formula (V) include 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, Aminopropyl) polydimethylsiloxane (e.g., tetramer to octamer of dimethylsiloxane at the aminopropyl end), 1,3-bis (3-aminophenoxymethyl) -1,1,3,3- Tetramethyldisiloxane,?,? - bis (3-aminophenoxymethyl) polydimethylsiloxane, 1,3-bis (2- (3-aminophenoxy) ethyl) -1,1,3,3- (3-aminophenoxy) ethyl) polydimethylsiloxane, 1,3-bis (3- (3-aminophenoxy) propyl) -1,1,3,3- Tetramethyldisiloxane, and?,? - bis (3- (3-aminophenoxy) propyl) polydimethylsiloxane. In the case of the polysiloxane, the polysiloxane has an average degree of polymerization of 2 to 33 (about 250 to 3000 in terms of molecular weight), preferably an average degree of polymerization of 4 to 24 (about 400 to 2000 in terms of molecular weight).

Examples of the diamine compound represented by the formula (VI) include 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl 4,4'-diaminodiphenyl ether , 3,3'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 3,3'-dimethyl 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3 , 3'-dimethoxy 4,4'-diaminodiphenylmethane, 2,2'-bis (3-aminophenyl) propane, 4,4'-diaminodiphenylsulfone, Benzene, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 3,3'-diaminobiphenyl, 1,3-bis (3-aminophenoxy) benzene, 2,2- Bis [3-chloro-4- (4-aminophenoxy) phenyl] propane, 2,2- (4-aminophenoxy) phenyl] propane, 2,2-bis [3,5-dimethyl 4- Ethane, 1,1'-bis [3-chloro4- (4-aminophenoxy) phenyl] ethane, bis [4- (4-aminophenoxy) phenyl] methane, 4,4 '- [1,4-phenylenebis (1-methylethylidene)] bisaniline, (1-methylethylidene)] bis (2-methylbenzylidene)] bis [4,4 ' , 6-dimethylbisaniline), and the like. Two or more of these diamine compounds may be used in combination.

Examples of the diamine compound having an epoxy reactive group represented by the formula (VII) include 2,5-dihydroxy p-phenylenediamine, 3,3'-dihydroxy 4,4'-diaminodiphenyl ether , 4,3'-dihydroxy 3,4'-diaminodiphenyl ether, 3,3'-dihydroxy 4,4'-diaminobenzophenone, 3,3'-dihydroxy 4,4 ' -Diaminodiphenylmethane, 3,3'-dihydroxy 4,4'-diaminodiphenylsulfone, 4,4'-dihydroxy 3,3'-diaminodiphenylsulfone, 2,2'- Bis [3-hydroxy-4- (4-aminophenoxy) phenyl] methane, 3,3'-dicarboxy 4,4'- Diaminodiphenyl ether, 4,3'-dicarboxy 3,4'-diaminodiphenyl ether, 3,3'-dicarboxy 4,4'-diaminobenzophenone, 3,3'-dicarboxy 4, Diaminodiphenylmethane, 3,3'-dicarboxy 4,4'-diaminodiphenylsulfone, 4,4'-dicarboxy 3,3'-diaminodiphenylsulfone, 3,3'- Dicarboxybenzidine, 2,2'-bis [3- Le diplopia 4- (4-aminophenoxy) phenyl] propane, bis [3-carboxy-4- (4-aminophenoxy) phenyl] methane. Two or more of these diamine compounds may be used in combination.

In order to obtain the polyimide resin in the present invention, a siloxane compound having an amino group at both terminals and a diamine compound are reacted with the tetracarboxylic acid anhydride at a temperature of 20 to 150 ° C, preferably 0 to 60 ° C Reacting for several minutes to several days to produce a polyamic acid, and then imidizing the polyamic acid. Examples of the solvent include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide and N-methyl 2-pyrrolidone, , A sulfur-containing solvent such as dimethylsulfone, a phenol-based solvent such as phenol, cresol and xylenol, acetone, tetrahydrofuran, pyridine, tetramethylether and the like.

Examples of the imidation method include a method of dehydrating ring closure by heating and a method of chemically ring closure by using a dehydration ring closure catalyst. When dehydrating and ring-closing is carried out by heating, the reaction temperature is from 150 to 400 ° C, preferably from 180 to 350 ° C, and the reaction time is from several tens minutes to several days, preferably from 2 hours to 12 hours. When the compound is chemically closed, the dehydration ring-closing catalyst is preferably an acid anhydride such as acetic acid, propionic acid, butyric acid or benzoic acid, and pyridine which promotes the cyclization reaction. The amount of the catalyst is 200 mol% or more, preferably 300 to 1000 mol% of the total amount of the diamine.

In the polyimide resin used in the present invention, the structural unit represented by the formula (I) and the structural unit represented by the formula (II) and the formula (III) are arranged in a molar ratio of 5/95 to 50/50 desirable. The molar ratio of the structural unit represented by the formula (II) to the structural unit represented by the formula (III) is 0: 100 to 99: 1, preferably 80:20 to 95: 5, : 50 to 95: 5.

As described above, in order to impart flatness, it is necessary to be modified by silicon. However, the polyimide resin alone is flexible when heated, resulting in deterioration of W / B property and the like. In addition, in the case of a relatively rigid polyimide resin in which the amount of modification by silicon is suppressed, flatness can not be obtained and the temperature at the time of compression is too high. In order to solve this problem, the problem of the former can be suppressed from becoming flexible at high temperature by using an epoxy resin in combination, and the latter problem can be suppressed by using an epoxy resin which is softened and melted at a lower temperature than the polyimide resin, The temperature can be lowered, and it can be put to practical use.

The epoxy resin is an epoxy resin having two or more epoxy groups in one molecule and is selected from the group consisting of cresol novolak type epoxy resin, phenol novolak type epoxy resin, epoxy resin containing biphenyl type skeleton, epoxy resin of naphthalene skeleton, Bisphenol A type, F type epoxy resin, dicyclopentadiene type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin and halogenated epoxy resin.

Among the epoxy resins, the multifunctional epoxy resin is suitable for improving the Tg of the adhesive layer and the hardness at high temperature. On the other hand, since the multifunctional epoxy resin tends to have a high softening point, a sock-type epoxy resin is more preferable in order to improve the meltability of the adhesive layer. Although the epoxy resin at both ends does not reach the multi-tubular shape in view of the Tg of the adhesive layer and the hardness at a high temperature, it is a preferable material for the deformation of the mask sheet as a result of the relatively low rigidity and is a multi- Is more preferable.

Although the straight-chain epoxy resin does not reach the multifunctional type in view of the Tg of the adhesive layer and the hardness at high temperature, it is a preferable material for the deformation of the mask sheet as a result of the relatively low rigidity, and the multifunctional epoxy resin, It can be further contained in an epoxy resin.

Examples of the multifunctional epoxy resin include triphenylmethane type epoxy resin (trade name: EPPN502H available from Nippon Kayaku Co., Ltd.), Epikote 828, 1001 manufactured by JER Corporation, naphthalene type epoxy resin (Trade name: HP4700, manufactured by DIC Corporation), cresol novolak type epoxy resin (trade name: EOCN1022, manufactured by Nippon Kayaku Co., Ltd.), and multifunctional epoxy resin (trade name: VG3101 manufactured by Printech Co., Ltd.).

Examples of the end-use epoxy resin include bisphenol A type epoxy resin (for example, Epicote 828 manufactured by JER), biphenyl type epoxy resin (for example, trade name: YX-4000 manufactured by JER), naphthalene Epoxy resin having a siloxane skeleton from the viewpoint of imparting more flexibility (for example, Shin-Etsu Chemical Co., Ltd.), epoxy resin KF105 and X-22-163), EXA4816 and EXA4822 available from DIC Corporation, and terminal epoxy of butanediol skeleton.

The epoxy resin of the siloxane skeleton is more preferable for deformation of the mask sheet. With respect to the siloxane skeleton, the siloxane moiety may exist even in the skeleton of the polyimide resin, but there is a stress relaxation effect on the curing shrinkage and the like when a relatively low-molecular-weight epoxy resin thermally cures. Since the multifunctional and the terminal epoxy resin have the opposite characteristics, a more preferable resin composition can be obtained by using the siloxane modified polyimide resin as the elastomer, the multifunctional epoxy resin and the terminal epoxy resin in combination. When the content is small, it is difficult to lower the softening temperature of the adhesive, and when the content is large, the flexibility of the adhesive is lowered, the adhesiveness with the heat resistant substrate is lowered, and the adhesive residue upon peeling off the mask sheet due to retraction tends to be a problem. The optimum amount of the content thereof is changed by the molecular weight and the functional group of the curing agent, and the content of the epoxy resin is preferably 15 to 45% by mass, and more preferably 20 to 40% by mass.

The adhesive layer contains a curing agent which undergoes a crosslinking reaction with an epoxy group. By containing the curing agent which reacts with the epoxy resin in a curing reaction, the hardness and the heat resistance after curing are improved, and the W / B property is also suitable. In addition, by curing, it is not melted at the time of molding sealing, and contact with the molding resin can be prevented, so that the adhesive force of the interface is not remarkably increased, and the peeling force of the mask sheet is improved. Examples of the curing agent include 3,3 ', 5,5'-tetramethyl 4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraethyl 4,4'-diaminodiphenylmethane, 3,3'-dimethyl 5,5'-diethyl 4,4'-diaminodiphenylmethane, 3,3'-dichloro 4,4'-diaminodiphenylmethane, 2,2 ', 3,3' - tetrachloro 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 3,3'-diaminobenzophenone, 3,3'-diaminodiphenylsulfone, 4,4'- Aromatic polyamines such as diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 4,4'-diaminobenzophenone and 3,4,4'-triaminodiphenylsulfone, aromatic polyamines such as boron trifluoride tri Amine compounds of boron trifluoride such as ethylamine complex, dicyandiamide, novolak phenol resins such as pt-butylphenol or bisphenol A skeleton, paraphenylene skeleton and biphenyl skeleton, and bisphenol compounds such as bisphenol A can be used have. A self-crosslinking resol resin of the above skeleton can also be used. Among them, a phenol-based curing agent having excellent heat resistance is preferable. In the control of the meltability and the like, it is appropriate to use them alone or in combination of two or more thereof. Further, imidazoles, diamines, triphenylphosphine accelerators and catalysts can be used for the purpose of controlling the curing rate.

The adhesive layer contains a fluorine additive for imparting releasability. The fluorine additive is a copolymer or a graft body containing at least one of an olefin containing a perfluoro group or a vinyl ether or a vinyl ester as a constituent material. As the fluorine graft polymer, there may be mentioned Chemytri LF-700, a fluorinated acrylic graft polymer which is available from JEON CHEMICAL INDUSTRIES. In addition, the fluorinated acrylic graft polymer is composed of a stem polymer and a plurality of branched polymers that grow from the stem polymer, the stem polymer is made of an acrylic polymer, and the branched polymer is made of a fluorine-containing polymer.

As the fluorine-containing block copolymer, a block copolymer composed of a fluorinated alkyl group-containing polymer segment and an acrylic polymer segment is commercially available under the trade name of MODIFY F series such as MODIFER F200, MODIFER F220, Dipper F2020, Modifer F3035, Modifier F600. As the fluorinated aliphatic polymer ester, those having properties of a nonionic surfactant are preferable, and a trade name: Novec FC-4430 available from 3M Co., Ltd. can be mentioned. As the fluorine additive, for example, a sulfonic acid salt containing a perfluoroalkyl group, an anionic surfactant such as a carboxylate containing a perfluoroalkyl group, a perfluoroalkyl alkylene oxide adduct, a fluorine group A fluorine-containing surfactant such as a lipophilic group-containing oligomer, a fluorine group, a hydrophilic group-containing oligomer, a fluorine group, a hydrophilic group and a lipophilic group-containing oligomer; These fluorine-containing additives may be used alone or in combination of two or more. The fluorine additive to be compounded may be a liquid and may be solid, but it is preferably liquid at 25 DEG C from the viewpoint of increasing the surface fluorine recovery rate of the adhesive layer and further improving the peelability. Examples of suitable fluorine additives include Megafac F-552, F-554, F-558, and F-477 (manufactured by DIC Co., Ltd.) which are oligomers of a fluorinated group and a lipophilic group in liquid at 25 占 폚.

The presence of the fluorine additive makes it possible to suppress the adhesion between the molding resin and the metal plate, and in particular, the problem of residual resin is improved. On the other hand, the fluorine-containing additive is effective in terms of imparting releasability, but it may also deteriorate the adhesiveness to the substrate. If the amount is too large, the adhesiveness is deteriorated too much and adhesiveness with a metal plate such as a frame is lowered. So that it is not practical. As a result of the examination, 0.5 to 5 phr (with respect to 100 g of the adhesive, excluding the fluorine-based material) is preferable.

The effect of fluoride additives on peelability is considered to be as follows. First, in the QFN process, a mask sheet is bonded on one side of a lead frame, and a semiconductor chip is mounted on the opposite side of the lead frame with a diatomic adhesive. However, when the adhesive is cured, out gas is generated from the diaphragm, Since gas is generated, plasma cleaning is carried out in order to improve the reliability of bonding by wire bonding in which leads and chips are connected with gold wires.

The molecular chains of the adhesive surface are cut by the plasma cleaning to produce a polar group and the surface is finely roughened so that the adhesion with the molding resin in the molding bag after wire bonding is improved and the peeling force And the problem that the adhesive remains on the molding resin part is likely to occur. However, by containing the fluorine-containing additive as in the present invention, the fluorine and fluorine-containing molecules are oriented or exposed to the surface layer on the adhesive surface of the mask sheet by the thermal history during wire bonding after being plasmaized, The problem is solved. Considering the orientation to the surface of fluorine, etc., the Tg of the adhesive layer in the mask sheet is preferably 90 to 200 占 폚. When the Tg after curing is lower than 90 DEG C, there is a problem in wire bonding property. When the Tg after curing exceeds 200 DEG C, since the fluorine additive is hardly exposed to the surface at the temperature history of wire bonding after plasma, Resulting in problems such as residual resin and the like.

The Tg in the present invention is determined by the peak temperature or displacement point of the loss coefficient determined by the temperature dependency of the dynamic viscoelasticity of the adhesive layer.

The sample size was 1 cm or more in length, 1 to 4 mm in width, and 5 to 40 탆 in thickness. Using a dynamic viscoelasticity automatic measuring device DDV-01 FP manufactured by Orientec Co., g in air. The adhesive layer is separated from the substrate layer, and the curing treatment is carried out at 175 캜 for 1 hour with the adhesive layer alone, and the above measurement is carried out. In the case where only the adhesive layer can not be obtained, measurement can be made with the constitution of the base layer and the adhesive layer. In the case of measurement with the constitution of the base layer and the adhesive layer, there is a case where the peak is not detected in the temperature characteristic of the loss coefficient. In this case, the loss behavior of the adhesive layer is determined from the characteristics of the base layer to determine Tg.

In order to change the melting property of the B stage (semi-cured state) and the hardness of the cured product, the filler may be contained in the adhesive layer for the purpose of adjusting the coefficient of thermal expansion, thermal conductivity, surface wrinkles, adhesiveness and the like. As the filler, an insulating filler is more preferable. It is generally appropriate to add inorganic or organic fillers.

Examples of the inorganic filler include pulverized silica, soluble silica, alumina, titanium oxide, beryllium oxide, magnesium oxide, calcium carbonate, titanium nitride, silicon nitride, boron nitride, titanium boride, tungsten boride, silicon carbide, titanium carbide Zirconium, molybdenum carbide, mica, zinc oxide, carbon black, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, antimony trioxide and the like, or trimethylsiloxane groups introduced into the surface of these materials. Examples of the organic filler include fillers composed of polyimide, polyamideimide, polyetheretherketone, polyetherimide, polyesterimide, nylon, silicone, and the like. In the case of the mask sheet, since the adhesive layer is as thin as about 5 占 퐉, the size of the filler that can be used is limited, and the average particle diameter is preferably 1 占 퐉 or less at D (50). Further, it is appropriate that 0.2 μm or less.

The meltability of the adhesive layer is important from the following point of view. After the mask sheet is attached, heat treatment is performed for curing of the diazotizing agent when mounting the chip. Generally, heat treatment is performed at about 175 ° C for about 1 hour at room temperature and for about 1 hour at about 175 ° C. In addition, there is also a case where the diamond touch agent is cured by passing a heating furnace or the like at 200 캜 for several minutes. The thermosetting adhesive layer tends to have a low viscosity at one time, and can be foamed by evaporation of moisture-absorbing moisture, curling of the foam when the mask sheet is attached, and the like. Further, when the curing speed is slow, the curing of the adhesive of the mask sheet becomes insufficient at the time of curing of the diazotizing agent. From such a point of view, the melt viscosity of the B stage is preferably such that the temperature at which the lowest limit of viscosity appears is in the range of 70 to 200 占 폚, preferably 90 to 180 占 폚, the viscosity of the lowest limit value is 4000 Pa 占 퐏 or more, Preferably 80000 Pa · s or more. That is, as shown in Fig. 1, it is preferable that the lowest limit value A has a temperature of 70 to 200 占 폚 and a viscosity of 4000 Pa 占 퐏 or more in the melt viscosity curve of the adhesive layer. To obtain such a melt viscosity, a composition of the above-mentioned polyimide resin, epoxy resin and curing agent is appropriately used, and the reaction state is controlled by adjusting the curing rate by an accelerator and a catalyst, or by heat treatment (aging) , It is possible to obtain an appropriate melt viscosity. The melt viscosity can be measured using a Young's Modulus Rheometer RS at a frequency of 1 Hz and a temperature rise rate of 10 ° C / min.

The thickness of the adhesive layer is 1 to 30 占 퐉, preferably 3 to 7 占 퐉. If the thickness of the adhesive layer is less than 1 占 퐉, molding resin will be lost when foreign matter or the like is mixed therein. If the thickness of the adhesive layer is greater than 30 占 퐉, wire bonding property may be deteriorated, have. Further, the thickness of the adhesive layer is preferably about 3 to 7 mu m because it affects the thermal expansion of the mask sheet.

Examples of the base layer include a polyester film, a polyethylene naphthalate film, a polyether sulfone, a polyetherimide film, a polyphenylene sulfide film, a PAR film, an aramid film, a polyimide film, and a liquid crystal polymer film. In addition, the film is not limited to a metal foil such as paper or copper foil. Non-woven fabrics such as polyparaphenylene benzobisoxazole (PBO), and aramid can also be applied.

The thickness of the base layer may be 10 to 125 탆, but it is generally 15 to 25 탆. In addition, when there is a difference in thermal expansion between the metal plate and the metal plate, a problem such as deformation occurs when the metal plate is attached to the metal plate. Therefore, the thermal expansion of the base layer is preferably about 13 to 25 ppm.

In the mask sheet of the present invention, if foreign matters are present on the surface or inside of the adhesive layer, a problem such as missing molding resin occurs. Therefore, a protective film is attached as necessary.

As the protective film, a peeled paper, a synthetic resin film such as polyethylene, polypropylene, or polyethylene terephthalate is used. When the base layer is a releasable film or a paper whose surface has been subjected to releasing treatment, the base layer may be peeled off and only the adhesive layer may be used as a mask sheet.

Next, an example of a method of manufacturing a semiconductor device using the mask sheet of the present invention will be briefly described with reference to FIGS. 2 and 3. FIG. Hereinafter, a case of manufacturing a QFN with a semiconductor device will be described as an example. 3 (a) to (f) are process drawings showing a method of manufacturing a QFN package using the lead frame shown in Fig. 2, and Fig. 3 2 is an enlarged schematic cross-sectional view of the frame taken along the line A-A 'in Fig.

First, a lead frame 20 having a schematic configuration shown in Fig. 2 is prepared. The lead frame 20 includes a plurality of semiconductor element mounting portions (die pad portions) 21 on which semiconductor elements such as IC chips are mounted in a matrix form, and a plurality of leads 22). 3 (a), the mask sheet 10 of the present invention is laminated on one side of the lead frame 20 in the mask sheet adhering step so that the adhesive layer (not shown) ). Further, as a method of attaching the mask sheet 10 to the lead frame 20, a lamination method and the like are suitable. Next, as shown in Fig. 3 (b), a die-touched material (not shown) is provided on the side where the mask sheet 10 is not adhered in the semiconductor element mounting portion 21 of the lead frame 20 A semiconductor element 30 such as an IC chip is mounted.

3 (c), the semiconductor element 30 and the lead 22 of the lead frame 20 are electrically connected to each other through a bonding wire 31 such as a gold wire in a wire bonding process do. Next, as shown in Fig. 3D, the semiconductor device in the manufacturing process shown in Fig. 3 (c) is placed in the mold in the resin sealing step, and a transfer molding (molding process) is performed using a molding resin , The semiconductor element 30 is sealed with the molding resin 40. Next, as shown in Fig. 3 (e), the mask sheet 10 is peeled from the molding resin 40 and the lead frame 20 in the mask sheet peeling step to form QFNs 50 in which a plurality of QFNs 50 are arranged The unit 60 can be formed. Finally, as shown in Fig. 3 (f), a plurality of QFNs 50 can be manufactured by dicing the QFN unit 60 along the periphery of each QFN 50 in the dicing step.

The mask sheet of the present invention can also be applied as a mask sheet of a semiconductor device by the following steps.

The adhesive layer side of the mask sheet of the present invention is laminated on a metal plate. The metal plate may be a thin metal foil such as copper. Thereafter, the adhesive layer is cured by heat. Then, the thin metal foil is formed into a predetermined pattern shape by etching or the like. After the thin metal foil is formed into a pattern shape, the semiconductor device is manufactured by subjecting the mask sheet to a diamond touch, a wire bonding, and a molding process as described above.

In the case of a mask sheet using an adhesive containing a conventional rubber and an epoxy resin, swelling or the like is caused on the acid or alkali by an etching solution used in a process such as etching or the like, The impurities contained in the adhesive are brought into contact with the molding resin and there is a problem such as migration to the molding resin portion or the chemical solution permeates the interface between the adhesive and the metal foil at the pattern end by the chemical liquid, Problems such as mold flash occur. Further, the mask sheet using the pressure-sensitive adhesive is not resistant to the etching solution.

In view of this, the mask sheet of the present invention hardly adsorbs impurity ions, has no penetration of the chemical solution at the interface between the adhesive and the metal foil at the end of the metal foil pattern, and hardly causes mold flash. In addition, the semiconductor device by such a process is applied to thin film formation or the like, and the metal foil can be made thinner.

[Example]

Hereinafter, examples and comparative examples of the present invention will be described.

Specifically, the polyimide resin was prepared as follows.

(Synthesis Example 1) (No epoxy reactivity)

In a flask equipped with a stirrer, 10.3 g (52 mmol) of 3,4'-diaminodiphenyl ether and 18.2 g (52 mmol) of 1,3-bis (3-aminophenoxymethyl) -1,1,3,3-tetramethyldisiloxane (100 mmol) of N-methyl-2-pyrrolidone (NMP) were added to the solution under ice-cooling, And stirring was continued for 1 hour. Then, the resulting solution was reacted at room temperature under nitrogen atmosphere for 3 hours to synthesize polyamic acid. To the resulting polyamic acid solution was added 50 ml of toluene and 1.0 g of p-toluenesulfonic acid, and the mixture was heated at 160 占 폚. The imidization reaction was carried out for 3 hours while separating water in the azeotropic state with toluene. The toluene was removed, and the obtained polyimide varnish was poured into methanol, and the resulting precipitate was separated, pulverized, washed, and dried to obtain 54.3 g (yield: 95%) of a polyimide resin. For this polyimide resin, infrared absorption spectra were measured and typical absorption of the imide was observed at 1718 and 1783 cm. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 2) (having epoxy reactivity)

(43 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2.3 g (9 mmol) of 3,3'-dicarboxy 4,4'-diaminodiphenylmethane, , 18.3 g (48 mmol) of 3-bis (3-aminophenoxymethyl) -1,1,3,3-tetramethyldisiloxane, 3,4,3 ', 4'-benzophenonetetracarboxylic acid dianhydride 32.22 62.5 g (yield: 93%) of a reactive polyimide resin was obtained in the same manner as in Synthesis Example 1, except that 300 ml of N-methyl-2-pyrrolidone (NMP) The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 3) (No epoxy reactivity)

33.7 g (82 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 13.8 g (18 mmol) of aminopropyl terminal dimethylsiloxane monomer, 2,3,3 ' 67.4 g (yield: 92%) of a polyimide resin was obtained in the same manner as in Synthesis Example 1, using 29.4 g (100 mmol) of phenyl tetracarboxylic acid dianhydride and 300 ml of N-methyl 2-pyrrolidone. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 4) (having epoxy reactivity)

(74 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2.35 g (8 mmol) of 3,3'-dicarboxy 4,4'- diaminodiphenylmethane, Propyl-terminated dimethylsiloxane hexamer, 29.4 g (100 mmol) of 2,3,3 ', 4'-biphenyltetracarboxylic acid dianhydride and 300 ml of N-methyl 2-pyrrolidone , 67.8 g (yield: 94%) of a polyimide resin was obtained in the same manner as in Synthesis Example 1. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 5) (No epoxy reactivity)

32.0 g (78 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 17.0 g (22 mmol) of aminopropyl terminal dimethylsiloxane monomer, 78.8 g (yield 97%) of a polyimide resin was obtained in the same manner as in Synthesis Example 1, except that 35.8 g (100 mmol) of dianhydride and 300 ml of N-methyl 2-pyrrolidone were used. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 6) (epoxy reactive)

(4 mmol) of 3,3'-dicarboxy 4,4'-diaminodiphenyl methane, 30.4 g (74 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] Propyl-terminated dimethylsiloxane hexamer was obtained by using 16.9 g (22 mmol) of bis (3,4-dicarboxyphenyl) sulfone anhydride and 300.8 ml of N-methyl 2-pyrrolidone, 75.0 g (yield: 93%) of a polyimide resin was obtained. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 7) (No epoxy reactivity)

(11 mmol) of bis (3-aminophenoxy) benzene, 26.1 g (89 mmol) of aminopropyl-terminated dimethylsiloxane monomer and 20.0 g (100 mmol) of bis (3,4-dicarboxyphenyl) Mmol) and N-methyl 2-pyrrolidone (300 ml) were used in the same manner as in Synthesis Example 1 to obtain 47.1 g (yield 93%) of a polyimide resin. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 8) (epoxy reactive)

23.6 g (81 mmol) of 1,3-bis (3-aminophenoxy) benzene, 2.1 g (9 mmol) of 3,3'-dihydroxy 4,4'- diaminodiphenylmethane, (100 mmol) of bis (3,4-dicarboxyphenyl) ether dianhydride and 300 ml of N-methyl 2-pyrrolidone were added 8.1 g (10 mmol) of octamer, (Yield: 91%) was obtained. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 9) (No epoxy reactivity)

28.7 g (70 mmol) of 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 23.1 g (30 mmol) of aminopropyl terminal dimethylsiloxane oligomer, 78.8 g (yield 97%) of a polyimide resin was obtained in the same manner as in Synthesis Example 1, except that 35.8 g (100 mmol) of dianhydride and 300 ml of N-methyl 2-pyrrolidone were used. The number average molecular weight and the glass transition temperature of the polyimide resin were measured. The results are shown in Table 1.

(Synthesis Example 10) (No epoxy reactivity, no siloxane skeleton)

(40 mmol) of 4,4'-methylene bis (2,6-diethylaniline 3.2 g (10 mmol), 1,3-bis (3-aminophenoxy) benzene, 78.7 g (yield 97%) of a polyimide resin was obtained in the same manner as in Synthesis Example 1, using 15.5 g (50 mmol) of an anhydride and 300 ml of N-methyl 2-pyrrolidone. Average molecular weight, and glass transition temperature were measured.

[Examples 1 to 16 and Comparative Examples 1 to 4]

Next, the polyimide resin, the epoxy resin, the curing agent, the fluorine additive and the accelerator were mixed in methyl ethyl ketone to prepare the adhesives of Examples 1 to 16 and Comparative Examples 1 to 4 according to the blend of the following Tables 2 and 3 . They were laminated on a base layer made of a polyimide resin film (trade name: Capton 100 EN, thickness 25 占 퐉, glass transition temperature 300 占 폚 or higher, thermal expansion coefficient 16 ppm / 占 폚 manufactured by Tooret Dupont) so that the thickness after drying was 5 占 퐉 And dried at 100 DEG C for 5 minutes to prepare a mask sheet having the adhesive layer of the present invention and a mask sheet for comparison.

In addition, the numerical values in Tables 2 and 3 show the mixing ratios of the masses of the polyimide resin, the epoxy resin, the curing agent, the fluorine additive and the accelerator.

[Comparative Examples 5 to 8]

In Comparative Examples 5, 6, 7, and 8, a comparative mask sheet was prepared in the same manner as in Example 1, except that an adhesive or a pressure-sensitive adhesive was produced as follows.

[Comparative Example 5]

The following compounds were stirred until they were mixed and dissolved to prepare an adhesive.

Acrylonitrile butadiene rubber 100 parts by mass

(Trade name: Nipol 1072, manufactured by Zeon)

Orthocresol novolak epoxy resin 50 parts by mass

(Trade name: EOCN 1020, manufactured by Nippon Kayaku Co., Ltd.)

Novolak phenol resin 50 parts by mass

(Trade name: CKM 2432, manufactured by Digestion Polymer Co., Ltd.)

· 2-ethyl 4-methylimidazole 0.5 parts by mass

Methyl ethyl ketone 800 parts by mass

[Comparative Example 6]

A solution (TSR-1512, solid concentration 60% by mass, manufactured by GE Dongjin Silicone) and a polyalkyl hydrogen siloxane (CR-51, average molecular weight 1300, manufactured by GE Dongji Silicone) containing polyalkenylsiloxane having an average molecular weight of 500,000 and a platinum catalyst Manufactured by Silicone Co.) were mixed at a mass ratio of 100: 1 to prepare an addition reaction type silicone pressure-sensitive adhesive.

[Comparative Example 7]

Only the polyimide resin of Synthesis Example 1 was dissolved in a tetrahydrofuran solution so that the solid content was 25 mass%, thereby producing an adhesive.

[Comparative Example 8]

The following compounds were mixed and stirred until melted to prepare an adhesive.

· 50 parts by mass of silicone main chain epoxy resin

(Trade name: X-22-163, molecular weight: about 400)

Novolak phenol resin 25 parts by mass

(Trade name: CKM 2432, manufactured by Digestion Polymer Co., Ltd.)

Fluorine Leveling Second Mass Part

(Trade name: Megacup F-482, manufactured by DIC)

· 2-ethyl 4-methylimidazole 0.1 parts by mass

Methyl ethyl ketone 800 parts by mass

<Properties>

The glass transition temperature (Tg), the melting viscosity and the lower limit of viscosity of the adhesive layer of the mask sheets of Examples 1 to 16 and Comparative Examples 1 to 8 were measured, and the results are shown in Tables 4 and 5.

&Lt; Evaluation result &gt;

Further, the following characteristics were measured for the mask sheets of Examples 1 to 16 and Comparative Examples 1 to 8, and the results are shown in Tables 4 and 5.

In addition, "-" in the evaluation results of Table 5 indicates that the measurement was interrupted because some evaluation results of the following flatness deformation, adhesion or bubble test were bad.

1. Planar transformation

The substrate was cut in a width direction of 5 cm and a length of 20 cm in a state without a protective film and allowed to stand in an environment of 20 to 25 ° C / 45 to 55% RH on a flat surface for 20 hours or more with the adhesive layer as a surface, The deformation of the direction was measured at both ends and the average was taken as the deformation amount. The deformation without practical problems is 2 mm or less.

2. Adhesiveness

A mask sheet having a width of 10 mm was laminated on a copper plate (125 占 퐉 thick 7025 type) with a metal roll at 150 占 폚 at a rate of 0.5 m / min and peeled at a tensile rate of 50 mm / min to measure the adhesive force. Practically, adhesion of 5 g / cm or more is problematic.

3. Bubble test between the mask sheet and the attached frame in the cure process (D / A) of the diaphragm

The above-mentioned copper plate was laminated with a 1-cm-wide mask sheet at a rate of 0.5 m / min with a metal roll at 150 캜. After the treatment was carried out for up to 175 DEG C for 30 minutes, it was confirmed whether or not foaming was further performed at 175 DEG C for 1 hour.

4. Wire Bonding (W / B)

Each package was mounted on a QFN lead frame (Au-Pd-Ni plated Cu lead frame, matrix array of 4 × 16 (64 in total), package size 10 mm × 10 mm, 84 pins) with external dimensions of 200 mm × 60 mm The mask sheets obtained in Examples and Comparative Examples were adhered by a heat lamination method. Then, a dummy chip (6 mm x 6 mm, thickness 0.4 mm) on which aluminum was deposited was mounted on the semiconductor element mounting portion of the lead frame using an epoxy-based diazo touch agent. Thereafter, the plasma cleaning was not performed, and the heating temperature was 210 DEG C, US power was 30, the load was 0.59 N, and the processing time was 10 msec / pin using a wire bonder (UTC-470 BI) The dummy chips and leads were electrically connected with gold wires. Sixty-four semiconductor devices thus obtained were inspected, and the number of semiconductor devices in which lead-side connection defects occurred was taken as the number of defective wire bonding defects.

5. Adhesive residue, mold flash

A mask sheet (not shown) was attached to a QFN lead frame (Au-Pd-Ni plated Cu lead frame, matrix array of 4 x 16 (64 in total), package size 10 mm x 10 mm, 84 pins) Was laminated at a rate of 0.3 m / min on a rubber roll at 140 占 폚 and subjected to a heat treatment at 175 占 폚 for 1 hour and an Ar plasma treatment at 450 占 폚 for 60 seconds in a chip mounting simulated condition and was molded and encapsulated. Thereafter, the mask sheet was peeled off at 90 degrees and 50 mm / min, and the presence or absence of residual adhesive (residual adhesive of the mask sheet on the molding resin) and the presence of mold flash (molding resin leakage) were confirmed.

With respect to the residual adhesive, the residue of the adhesive on the molding resin adhered to the adhesive portion of the mask sheet on the frame was observed with a four-fold stereoscopic microscope to determine whether or not the adhesive remained.

The presence or absence of molding resin unevenness (flash) on the frame was also observed with a four-fold stereoscopic microscope for the mold flash.

As a result of the evaluation described in Table 4, the mask sheets of the present invention of Examples 1 to 12 had planarity with flat strain of 2 mm or less. Further, the adhesive property is not less than 5 g / cm, and taping occurs at L / F at a low temperature. Further, even in the bubble test, foaming does not occur, and even when exposed to a high temperature, thermal heat is hard to occur. In addition, it was confirmed that it is excellent also in the wire bonding property, the adhesive residue, and the mold flash test. The results of Examples 13 to 16 are inferior to those of Examples 1 to 12.

On the other hand, in the mask sheet of the comparative example in Table 5, the mask sheet of Comparative Example 1 and Comparative Example 7 exceeded 2 mm in planar deformation, and had a problem in practical use. In addition, the mask sheets of Comparative Example 1, Comparative Example 3, Comparative Example 4, and Comparative Example 7 had an adhesive property smaller than 5 g / cm and had practical problems. In addition, the mask sheet of Comparative Example 8 foamed in the foam test, and the mask sheets of Comparative Example 2 and Comparative Examples 3 to 6 were practically problematic in the test of wire bonding property, adhesive residue, and mold flash.

[Example 17]

The mask sheet obtained in Example 1 was hot-pressed at 140 占 폚 in a copper foil (trade name: FQ VLP 18 占 퐉) made by Semiconductor Co., Ltd., and then heat-treated at 175 占 폚 for 1 hour to cure the adhesive layer. Then, the copper foil layer was etched to have a lead frame pattern for QFN as shown in Fig. 1 by using an etchant of 40 Bowes using ferric oxide. Thereafter, the lead frame pattern for copper foil made of copper foil to which the mask sheet was adhered was evaluated for wire bonding (W / B), adhesive remnants and mold flash in the same manner as in Example 1 above.

As a result, it was confirmed that there was no defect in the wire bonding, no residual adhesive, and no mold flash. Thus, the mask sheet of the present invention can be laminated on a thin metal foil such as copper, and then the adhesive is cured by heat. Then, the thin metal foil is formed into a predetermined pattern shape through etching, It has been confirmed that the method is suitable for a process of manufacturing a semiconductor device through a molding process.

[Comparative Example 9]

The mask sheet obtained in Comparative Example 5 was hot-pressed at 140 占 폚 in a copper foil (trade name: FQ VLP 18 占 퐉) made by Semiconductor Co., Ltd., and then heat-treated at 175 占 폚 for 1 hour to cure the adhesive layer. Then, the copper foil layer was etched to have a lead frame pattern for QFN as shown in Fig. 1 by using an etchant of 40 Bowes using ferric oxide. Thereafter, the lead frame pattern for copper foil made of copper foil to which the mask sheet was adhered was evaluated for wire bonding (W / B), adhesive remnants and mold flash in the same manner as in Example 1 above. As a result, defective wire bonding occurred 15, adhesive remnant and mold flash also occurred. This is thought to be due to the fact that the adhesive caused swelling or the like by the etching solution.

10: Mask sheet for semiconductor device manufacturing
20: Lead frame
30: Semiconductor device
31: Bonding wire
40: molding resin

Claims (3)

In which a thermosetting adhesive layer is laminated on one surface of a substrate layer and is adhered to a metal plate in a releasable manner,
Wherein the thermosetting adhesive layer comprises a polyimide resin containing a siloxane skeleton having a glass transition temperature of 45 to 170 占 폚; Epoxy resin; Curing agent; And a fluorine additive,
The fluorine-containing additive may be at least one selected from the group consisting of a fluorine-containing additive containing perfluoro group, an oligomer containing fluorine group and lipophilic group, an oligomer containing fluorine group and hydrophilic group, and an oligomer containing fluorine group, Two or more species,
Wherein the polyimide resin accounts for 35 to 75 mass% of the thermosetting adhesive layer, and the fluorine additive accounts for 0.5 to 5.0 mass%.
The mask sheet for manufacturing a semiconductor device according to claim 1, wherein the minimum value of the temperature-sensitive adhesive curve of the thermosetting adhesive layer has a temperature of 70 to 200 ° C and the viscosity of the lowest limit value is 4000 Pa · s or more.
A method of manufacturing a semiconductor device, comprising: laminating a thermosetting adhesive layer of a mask sheet for manufacturing a semiconductor device of claim 1 on a metal plate; forming the metal plate in a predetermined pattern; mounting the semiconductor chip thereon; molding the mask sheet; Wherein the semiconductor device is a semiconductor device.

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