JP2013112730A - Sheet-shaped sealing composition and method for producing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-shaped sealing composition having flexibility stable with time, and capable of sufficiently exhibiting flux function by a carboxylic acid, and to provide a method for producing a semiconductor element by using the composition.SOLUTION: The sheet-shaped sealing composition 2 comprises a thermoplastic resin having ≥100,000 of a weight-average molecular weight, an epoxy resin, a curing accelerator and a carboxy group-containing compound having ≥3.5 of pKa. The method for producing the semiconductor device 20 includes a step of dicing a semiconductor wafer 3, and obtaining a semiconductor element with the sheet-shaped sealing composition.

Description

  The present invention relates to a sheet-shaped sealing composition and a method for manufacturing a semiconductor device.

  In recent years, the demand for high-density packaging due to the miniaturization and thinning of electronic devices has increased rapidly. For this reason, the surface mount type suitable for high-density mounting is the mainstream of the semiconductor package instead of the conventional pin insertion type. In this surface mount type, the lead is directly soldered to a printed circuit board or the like. As a heating method, the entire package is heated and mounted by infrared reflow, vapor phase reflow, solder dipping, or the like.

  After the surface mounting, the space between the semiconductor element and the substrate is filled with a sealing resin in order to protect the surface of the semiconductor element and to ensure the connection reliability between the semiconductor element and the substrate. As such a sealing resin, a liquid sealing resin is widely used.

  In mounting the semiconductor element on the adherend, electrodes such as solder bumps provided on the semiconductor element are melted to electrically connect them. At that time, a flux agent derived from carboxylic acid or the like may be added to the liquid sealing resin for the purpose of removing the oxide film on the electrode surface or improving the wettability of the solder (Patent Document 1).

  As described above, the space between the semiconductor element and the substrate can be filled while adding a fluxing agent to the liquid sealing resin to achieve a good electrical connection. It is difficult to adjust the injection position and the injection amount. Then, the technique of filling the space between a semiconductor element and a board | substrate using the sealing resin on a sheet form or a film is also proposed (patent document 2).

  In general, as a process using a sheet-shaped sealing resin, after a sheet-shaped sealing resin is attached to a semiconductor wafer, the semiconductor element is diced to form a semiconductor element. A procedure of filling a space between an adherend such as a substrate and the semiconductor element with a sheet-like sealing resin integrated with the semiconductor element while being electrically connected to and mounted on the semiconductor element is employed. Recently, a technique of adding a carboxylic acid fluxing agent to a sheet-like sealing resin has been proposed (Patent Document 3).

Japanese Patent No. 3868179 Japanese Patent No. 2833111 US Pat. No. 5,128,746

  In addition to the flexibility required for handling properties as a sheet-like sealing composition, the flux agent has sufficient flux function when mounting semiconductor elements as the required properties of a sheet-like sealing resin added with a carboxylic acid-based flux agent It can be demonstrated. That is, since the carboxylic acid flux agent is highly reactive with the epoxy resin added as a thermosetting resin, both react over time immediately after the sheet-shaped sealing composition is produced, The flexibility of the sealing composition may be reduced. In addition, the flux agent reacts with the epoxy resin before the flux function is manifested by heat at the time of mounting, and the flux function for solder joining may not be sufficiently exhibited.

  In Patent Document 3, the space between the semiconductor element and the substrate can be easily filled, but there is room for improvement in terms of the stability over time of the flexibility. A flux agent may not express a flux function.

  Accordingly, an object of the present invention is to provide a sheet-shaped encapsulating composition that has a flexible property that is stable over time and that can sufficiently exhibit the flux function of a carboxylic acid, and a method for manufacturing a semiconductor element using the same. To do.

  The inventors of the present application have made extensive studies and found that the object can be achieved by employing a specific resin composition and carboxylic acid, and have completed the present invention.

That is, the sheet-like sealing composition of the present invention is
A thermoplastic resin having a weight average molecular weight of 100,000 or more;
Epoxy resin,
A curing accelerator;
and a carboxyl group-containing compound having a pKa of 3.5 or more.

  The sheet-like sealing composition (hereinafter sometimes simply referred to as “sealing composition”) is a flux group containing a carboxyl group-containing compound (hereinafter simply referred to as “carboxyl group-containing”) having a pKa of 3.5 or more. ) May be used to suppress the generation of carboxylate ions, and thereby the reactivity with the epoxy resin can also be suppressed. As a result, the carboxyl group-containing compound does not immediately react with the epoxy resin even by heat at the time of mounting the semiconductor, and can sufficiently exhibit the flux function by heat applied over time thereafter. Moreover, in addition to the adoption of the specific carboxyl group-containing compound, since it contains not only an epoxy resin but also a thermoplastic resin having a weight average molecular weight of 100,000 or more, appropriate flexibility can be expressed over time, Stable flexibility can be exhibited over time.

In the sealing resin composition, the carboxyl group-containing compound is
An aromatic carboxylic acid having at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryloxy group, an aryl group, and an alkylamino group in the molecule, and one or more carboxyl groups in the molecule It is preferably at least one selected from the group consisting of aliphatic carboxylic acids having 8 or more carbon atoms.

  By selecting the carboxyl group-containing compound from the aromatic carboxylic acid and the aliphatic carboxylic acid having a specific substituent as described above, the reaction with the epoxy resin is suppressed, and thereby the flexibility over time is stable. And the expression of the flux function can be efficiently achieved.

  In the sealing composition, the aromatic carboxylic acid has an alkyl group, an alkoxy group, an aryloxy group, an aryl group, or an alkylamino group in which at least one of the 2-position, 4-position, and 6-position is independently hydrogen atom. A benzoic acid derivative substituted with is preferable. The presence of the substituent of the benzoic acid derivative at a specific position can further suppress the reactivity with the epoxy resin, which contributes to the stability over time of the flexibility and the expression of the flux function. it can.

  Furthermore, the benzoic acid derivative is preferably a benzoic acid derivative in which the hydrogen atom at the 2-position or 4-position is substituted with a methoxy group, a phenoxy group, a phenyl group or a dimethylamino group. Such a benzoic acid derivative is easily available, and it is possible to more efficiently achieve suppression of reactivity with the epoxy resin, flexibility over time due to this, and expression of the flux function. it can.

  In the sealing composition, the benzoic acid derivative preferably does not contain a hydroxyl group. By eliminating the hydroxyl group that can be a reaction point with the epoxy resin, the sealing composition can suitably exhibit the flux function while maintaining flexibility.

  In the sealing composition, the aliphatic carboxylic acid is preferably a chain aliphatic dicarboxylic acid having 8 to 12 carbon atoms or an alicyclic dicarboxylic acid. Since such specific aliphatic carboxylic acid has a bulky structure, the reactivity with an epoxy resin can be suppressed by steric hindrance. At the same time, the flux function can be sufficiently exhibited by using dicarboxylic acid.

  It is preferable that the sealing composition further includes a phenol-based curing agent. Thereby, a crosslinked structure with an epoxy resin can be constructed, and the thermal stability of the encapsulating resin composition after curing can be improved.

  In the sealing composition, the thermoplastic resin is preferably an acrylic resin. Thereby, especially the adhesiveness and intensity | strength after hardening of a sealing composition can be improved, and connection reliability can be improved.

In the present invention, a bonding step of bonding the surface of the semiconductor wafer connecting member formed thereon and the sheet-shaped sealing composition;
A dicing step of dicing the semiconductor wafer to form a semiconductor element with the sheet-shaped sealing composition;
A connection step of electrically connecting the semiconductor element and the adherend through the connection member while filling a space between the adherend and the semiconductor element with the sheet-shaped sealing composition. A method for manufacturing a semiconductor device is also included.

It is a cross-sectional schematic diagram which shows the sheet-like sealing composition which concerns on one Embodiment of this invention. It is a cross-sectional schematic diagram which shows the manufacturing process of the semiconductor device which concerns on one Embodiment of this invention.

<Sheet-like sealing composition>
The sheet-like sealing composition of the present invention contains a thermoplastic resin having a weight average molecular weight of 100,000 or more, an epoxy resin, a curing accelerator, and a carboxyl group-containing compound having a pKa of 3.5 or more. Hereinafter, an embodiment of the present invention will be described with reference to the drawings as necessary.

(Thermoplastic resin with a weight average molecular weight of 100,000 or more)
As thermoplastic resins having a weight average molecular weight of 100,000 or more, natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, Examples include polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon and 6,6-nylon, phenoxy resin, acrylic resin, saturated polyester resin such as PET and PBT, polyamideimide resin, or fluorine resin. It is done. These thermoplastic resins can be used alone or in combination of two or more. Of these thermoplastic resins, an acrylic resin that has few ionic impurities and high heat resistance and can ensure the reliability of the semiconductor element is particularly preferable.

  The acrylic resin is not particularly limited, and includes one or two or more esters of acrylic acid or methacrylic acid having a linear or branched alkyl group having 30 or less carbon atoms, particularly 4 to 18 carbon atoms. Examples include polymers as components. Examples of the alkyl group include a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, amyl group, isoamyl group, hexyl group, heptyl group, cyclohexyl group, 2 -Ethylhexyl group, octyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, lauryl group, tridecyl group, tetradecyl group, stearyl group, octadecyl group, dodecyl group and the like.

  Further, the other monomer forming the polymer is not particularly limited, and for example, acrylonitrile, acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid or croton Carboxyl group-containing monomers such as acids, acid anhydride monomers such as maleic anhydride or itaconic anhydride, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, (meth) acrylic 4-hydroxybutyl acid, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate or (4-hydroxy Methylcyclo Hydroxyl group-containing monomers such as xyl) -methyl acrylate, styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate Alternatively, a sulfonic acid group-containing monomer such as (meth) acryloyloxynaphthalene sulfonic acid or the like, or a phosphoric acid group-containing monomer such as 2-hydroxyethylacryloyl phosphate may be used.

The weight average molecular weight of the thermoplastic resin is not particularly limited as long as it is 100,000 or more, and the weight average according to the characteristics of various resins while considering the flexibility, adhesiveness after curing, strength, etc. of the sealing composition Molecular weight can be imparted. For example, in the case of the acrylic resin, the weight average molecular weight is preferably about 100,000 to 3,000,000, more preferably 500,000 to 1,000,000. In addition, the measuring method of a weight average molecular weight can be measured with the following method. A sample is dissolved in THF at 0.1 wt%, and the weight average molecular weight is measured by polystyrene conversion using GPC (gel permeation chromatography). Detailed measurement conditions are as follows.
<Measurement conditions of weight average molecular weight>
GPC device: Tosoh HLC-8120GPC
Column: manufactured by Tosoh Corporation, (GMHHR-H) + (GMHHR-H) + (G2000HHR)
Flow rate: 0.8ml / min
Concentration: 0.1 wt%
Injection volume: 100 μl
Column temperature: 40 ° C
Eluent: THF

  The content of the thermoplastic resin is not particularly limited, and may be set in consideration of flexibility of the sealing composition, adhesiveness and strength after curing, and the like. As content of a thermoplastic resin, 5-150 weight part is preferable with respect to 100 weight part of below-mentioned epoxy resins, and 10-100 weight part is more preferable.

  The glass transition temperature (Tg) of the thermoplastic resin is preferably −40 to 20 ° C., more preferably −30 to 0 ° C., from the viewpoint of imparting flexibility to the sheet-shaped sealing composition. The glass transition temperature was measured by cutting a film-shaped thermoplastic resin into a strip shape having a thickness of 200 μm, a length of 400 mm (measurement length), and a width of 10 mm with a cutter knife, and a solid viscoelasticity measuring device (RSAIII, The storage elastic modulus and loss elastic modulus at −50 to 300 ° C. are measured using a rheometric scientific product). The measurement conditions are a frequency of 1 Hz and a heating rate of 10 ° C./min. Further, the glass transition temperature can be obtained by calculating the value of tan δ (G ″ (loss elastic modulus) / G ′ (storage elastic modulus)).

(Epoxy resin)
The epoxy resin is not particularly limited as long as it is generally used as an adhesive composition. For example, bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, Bifunctional epoxy resin such as biphenyl type, naphthalene type, fluorene type, phenol novolac type, orthocresol novolak type, trishydroxyphenylmethane type, tetraphenylolethane type, etc., or hydantoin type, trisglycidyl isocyanurate type Alternatively, an epoxy resin such as a glycidylamine type is used. These can be used alone or in combination of two or more. Of these epoxy resins, novolac type epoxy resins, biphenyl type epoxy resins, trishydroxyphenylmethane type resins or tetraphenylolethane type epoxy resins are particularly preferred. This is because these epoxy resins are rich in reactivity with a phenol resin as a curing agent and are excellent in heat resistance and the like.

  The content of the epoxy resin is not particularly limited, and from the viewpoint of ensuring the heat resistance of the sealing composition and the elastic modulus at high temperature, the total weight of all resins in the sealing composition (when a phenolic curing agent is included) Is preferably 10 to 80% by weight, and more preferably 20 to 50% by weight.

  The epoxy resin preferably has an epoxy equivalent of 100 to 300 g / eq, more preferably 150 to 200 g / eq. Heat resistance can be improved more by making the epoxy equivalent of the said epoxy resin into the said range.

(Curing accelerator)
The sealing composition of the present embodiment includes a curing accelerator of an epoxy resin (a phenolic curing agent when included). The curing accelerator is not particularly limited, and can be appropriately selected from known curing accelerators. A hardening accelerator can be used individually or in combination of 2 or more types. As a hardening accelerator, an amine hardening accelerator, a phosphorus hardening accelerator, an imidazole hardening accelerator, a boron hardening accelerator, a phosphorus-boron hardening accelerator etc. can be used, for example.

  The amine curing accelerator is not particularly limited, and examples thereof include monoethanolamine trifluoroborate (manufactured by Stella Chemifa Corporation), dicyandiamide (manufactured by Nacalai Tesque Corporation), and the like.

  The phosphorus curing accelerator is not particularly limited, and examples thereof include triorganophosphine such as triphenylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, tri (nonylphenyl) phosphine, diphenyltolylphosphine. , Tetraphenylphosphonium bromide (trade name; TPP-PB), methyltriphenylphosphonium (trade name; TPP-MB), methyltriphenylphosphonium chloride (trade name; TPP-MC), methoxymethyltriphenylphosphonium (trade name; TPP-MOC), benzyltriphenylphosphonium chloride (trade name; TPP-ZC), and the like (all manufactured by Hokuko Chemical Co., Ltd.). The triphenylphosphine compound is preferably substantially insoluble in the epoxy resin. It can suppress that thermosetting progresses too much that it is insoluble with respect to an epoxy resin. Examples of the thermosetting catalyst having a triphenylphosphine structure and substantially insoluble in the epoxy resin include methyltriphenylphosphonium (trade name: TPP-MB). The “insoluble” means that the thermosetting catalyst made of a triphenylphosphine compound is insoluble in a solvent made of an epoxy resin, and more specifically, a temperature range of 10 to 40 ° C. It means that 10% by weight or more does not dissolve.

  Examples of the imidazole curing accelerator include 2-methylimidazole (trade name; 2MZ), 2-undecylimidazole (trade name; C11-Z), 2-heptadecylimidazole (trade name; C17Z), and 1,2- Dimethylimidazole (trade name; 1.2 DMZ), 2-ethyl-4-methylimidazole (trade name; 2E4MZ), 2-phenylimidazole (trade name; 2PZ), 2-phenyl-4-methylimidazole (trade name; 2P4MZ) ), 1-benzyl-2-methylimidazole (trade name; 1B2MZ), 1-benzyl-2-phenylimidazole (trade name; 1B2PZ), 1-cyanoethyl-2-methylimidazole (trade name; 2MZ-CN), 1 -Cyanoethyl-2-undecylimidazole (trade name; C11Z-CN), 1-cyano Tyl-2-phenylimidazolium trimellitate (trade name; 2PZCNS-PW), 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine (trade name; 2MZ -A), 2,4-diamino-6- [2'-undecylimidazolyl- (1 ')]-ethyl-s-triazine (trade name; C11Z-A), 2,4-diamino-6- [2 '-Ethyl-4'-methylimidazolyl- (1')]-ethyl-s-triazine (trade name; 2E4MZ-A), 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] -Ethyl-s-triazine isocyanuric acid adduct (trade name; 2MA-OK), 2-phenyl-4,5-dihydroxymethylimidazole (trade name; 2PHZ-PW), 2-phenyl-4-methyl-5 Hydroxymethylimidazole (trade name; 2P4MHZ-PW), and the like (all manufactured by Shikoku Chemicals Corporation).

  The boron-based curing accelerator is not particularly limited, and examples thereof include trichloroborane.

  The phosphorus-boron curing accelerator is not particularly limited, and examples thereof include tetraphenylphosphonium tetraphenylborate (trade name; TPP-K), tetraphenylphosphonium tetra-p-triborate (trade name; TPP-MK), and benzyl. Examples include triphenylphosphonium tetraphenylborate (trade name; TPP-ZK), triphenylphosphine triphenylborane (trade name; TPP-S), and the like (all manufactured by Hokuko Chemical Co., Ltd.).

  The content of the curing accelerator is preferably 0.01% by weight or more and 10% by weight or less based on the total amount of the thermosetting resin (including the weight of the phenolic curing agent when it is included). By setting the content of the curing accelerator to 0.01% by weight or more, curing can be made sufficient. Moreover, manufacturing cost can be reduced by making content of a hardening accelerator into 10 weight% or less. The content of the curing accelerator is more preferably from 0.1% by weight to 5% by weight, and further preferably from 0.3% by weight to 3% by weight, based on the total amount of the thermosetting resin.

(Carboxyl group-containing compound having a pKa of 3.5 or more)
As the carboxyl group-containing compound contained in the sheet-shaped sealing composition according to this embodiment, a compound having at least one carboxyl group in the molecule, an acid dissociation constant pKa of 3.5 or more, and a flux function If it is, it will not specifically limit. The pKa of the carboxyl group-containing compound may be 3.5 or more, but from the viewpoints of suppressing the reaction with the epoxy resin and exhibiting the stability of the flexibility over time and the flux function, it is 3.5 or more and 7.0. The following is preferable, and 4.0 or more and 6.0 or less are more preferable. In the case where the carboxyl group has two or more is an acid dissociation constant of the first dissociation constant pKa _1, which the first dissociation constant pKa ₁ is in the above range is preferred. Further, pKa is a dilute aqueous solution under conditions carboxyl group-containing compounds, acid dissociation constant ^{_{Ka = [H 3 O +]}} [B -] / [BH] was measured, determined by the pKa = -logKa. Here, BH represents a carboxyl group-containing compound, and B ⁻ represents a conjugate base of the carboxyl group-containing compound. The measuring method of pKa can be calculated from the concentration of the relevant substance and the hydrogen ion concentration by measuring the hydrogen ion concentration using a pH meter.

  Examples of the carboxyl group-containing compound include an aromatic carboxylic acid having at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryloxy group, an aryl group, and an alkylamino group (hereinafter simply referred to as “carboxyl group-containing compound”). As well as an aliphatic carboxylic acid having one or more carboxyl groups in the molecule and having 8 or more carbon atoms (hereinafter, simply referred to as “aliphatic carboxylic acid”). .) Is preferably at least one selected from the group consisting of:

(Aromatic carboxylic acid)
The aromatic carboxylic acid is not particularly limited as long as it has at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryloxy group, an aryl group, and an alkylamino group in the molecule. The parent skeleton excluding the above substituent of the aromatic carboxylic acid is not particularly limited, and examples thereof include benzoic acid and naphthalene carboxylic acid. Aromatic carboxylic acids have the above substituents on the aromatic rings of these parent skeletons. Among these, benzoic acid is preferable as the base skeleton of the aromatic carboxylic acid from the viewpoint of stability in the sheet-like sealing composition and low reactivity with the epoxy resin.

  In the aromatic carboxylic acid, specifically, at least one hydrogen atom in the 2-position, 4-position and 6-position is independently substituted with an alkyl group, an alkoxy group, an aryloxy group, an aryl group or an alkylamino group. It is preferably a benzoic acid derivative (hereinafter sometimes simply referred to as “benzoic acid derivative”). In such a benzoic acid derivative, the predetermined substituent is present alone or in combination at at least one of the 2-position, 4-position and 6-position of benzoic acid. Specific examples of the substitution position of the substituent of the benzoic acid derivative include 2-position, 4-position, 2-position and 4-position, 2-position and 6-position, 2-position, 4-position and 6-position. Among these, in order to suppress the reaction with the epoxy resin and maintain the flexibility stability over time, and to express the flux function particularly efficiently, it has a substituent at the 2-position or 4-position. Is preferred.

  Examples of the alkyl group in the aromatic carboxylic acid include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n Examples thereof include alkyl groups having 1 to 10 carbon atoms such as -pentyl group, n-hexyl group, n-heptyl group and n-octyl group. Among these, a methyl group or an ethyl group is preferable from the viewpoint of pKa adjustment and flux function expression.

  Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an n-butoxy group, an n-hexanoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, and a t-butoxy group. Although a C1-C10 alkoxy group is mentioned, From the same point as the above, a C1-C4 alkoxy group is preferable, a methoxy group and an ethoxy group are more preferable, and a methoxy group is especially preferable.

  As said aryloxy group, a phenoxy group, p-tolyloxy group, etc. are mentioned, for example, A phenoxy group is preferable from a viewpoint similar to the above.

  Examples of the aryl group include aryl groups having 6 to 20 carbon atoms such as a phenyl group, toluyl group, benzyl group, methylbenzyl group, xylyl group, mesityl group, naphthyl group, and anthryl group. A phenyl group is preferred.

  As said alkylamino group, the amino group which has a C1-C10 alkyl group as a substituent can be used suitably. Specific examples of the alkylamino group include a methylamino group, an ethylamino group, a propylamino group, a dimethylamino group, a diethylamino group, a dipropylamino group, and the like. From the same viewpoint as described above, a dimethylamino group is preferable.

  In the alkyl group, alkoxy group, aryloxy group, aryl group or alkylamino group, one or more hydrogen atoms may be independently substituted. Examples of such an additional substituent include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, a 2-methylpropoxy group, a 1-methylpropoxy group, and a t-butoxy group. C1-C4 alkoxy group, cyano group, cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 4-cyanobutyl group and other cyanoalkyl groups having 2-5 carbon atoms, methoxycarbonyl group, ethoxycarbonyl group , Alkoxycarbonyl groups having 2 to 5 carbon atoms such as t-butoxycarbonyl group, alkoxycarbonylalkoxy groups having 3 to 6 carbon atoms such as methoxycarbonylmethoxy group, ethoxycarbonylmethoxy group, and t-butoxycarbonylmethoxy group, fluorine, chlorine Halogen atoms such as, fluoromethyl group, trifluoromethyl group, pentafur Fluoroalkyl groups such as Roechiru group.

  As a benzoic acid derivative having a specific combination of substitution position and substituent, 2-aryloxybenzoic acid, 2-arylbenzoic acid, 4-alkoxybenzoic acid, and 4-alkylaminobenzoic acid are preferable.

  The benzoic acid derivative preferably does not contain a hydroxyl group. By excluding the hydroxyl group that can be a reaction point with the epoxy resin, the sealing composition can maintain the flexibility with time and suitably exhibit the flux function.

(Aliphatic carboxylic acid)
The aliphatic carboxylic acid is not particularly limited, and may be any of a chain aliphatic (mono) carboxylic acid, an alicyclic (mono) carboxylic acid, a chain aliphatic polyvalent carboxylic acid, or an alicyclic polyvalent carboxylic acid. It may be. Moreover, you may use combining each aspect.

  Examples of chain aliphatic (mono) carboxylic acids include octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, and the like, oleic acid, elaidic acid, erucic acid, Examples thereof include unsaturated fatty acids such as nervonic acid, linolenic acid, stearidonic acid, eicosapentaenoic acid, linoleic acid and linolenic acid.

  Examples of alicyclic (mono) carboxylic acids include monocyclic carboxylic acids such as cycloheptanecarboxylic acid and cyclooctanecarboxylic acid, norbornanecarboxylic acid, tricyclodecanecarboxylic acid, tetracyclododecanecarboxylic acid, adamantanecarboxylic acid, and methyladamantane. Examples thereof include polycyclic or bridged alicyclic carboxylic acids having 8 to 20 carbon atoms such as carboxylic acid, ethyladamantanecarboxylic acid, and butyladamantanecarboxylic acid.

  Examples of the chain aliphatic polyvalent carboxylic acid include carboxylic acids in which one or more carboxyl groups are further added to the chain aliphatic (mono) carboxylic acid. Among these, the chain aliphatic dicarboxylic acid is an epoxy resin. Is preferable in that the flux function is suitably exhibited. Examples of the chain aliphatic dicarboxylic acid include octanedioic acid, nonanedioic acid, decanedioic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, etc. Is a chain aliphatic dicarboxylic acid having a molecular weight of 8 to 12.

  Examples of the alicyclic polyvalent carboxylic acid include carboxylic acids in which one or more carboxyl groups are further added to the alicyclic (mono) carboxylic acid. Among these, alicyclic dicarboxylic acids are less reactive to epoxy resins. In view of the properties and the flux function expression. Examples of the alicyclic dicarboxylic acids include polycyclic or bridged alicyclic dicarboxylic acids such as monocyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, cycloheptane dicarboxylic acid, and cyclooctane dicarboxylic acid, norbornane dicarboxylic acid, and adamantane dicarboxylic acid. Etc.

  In the above aliphatic carboxylic acids having 8 or more carbon atoms, one or more hydrogen atoms may be substituted with the additional substituent.

  The addition amount of the carboxyl group-containing compound as a fluxing agent may be such that the flux function is exerted, and is preferably 0.1 to 20% by weight relative to the total weight of the sealing composition, 0.5 to 10 Weight percent is more preferred.

(Phenolic curing agent)
It is preferable that the sealing composition which concerns on this embodiment contains a phenol type hardening | curing agent. The phenolic curing agent acts as a curing agent for the epoxy resin, and includes, for example, a novolac type phenol resin such as a phenol novolak resin, a phenol aralkyl resin, a cresol novolak resin, a tert-butylphenol novolak resin, a nonylphenol novolak resin, and a resole. Examples thereof include polyphenol styrene such as type phenol resin and polyparaoxy styrene. These can be used alone or in combination of two or more. Of these phenolic curing agents, phenol novolac resins and phenol aralkyl resins are particularly preferred. This is because the connection reliability of the semiconductor device can be improved.

  The mixing ratio of the epoxy resin and the phenolic curing agent may be such that, for example, the hydroxyl group in the phenolic curing agent is 0.5 to 2.0 equivalents per 1 equivalent of the epoxy group in the epoxy resin component. Is preferred. More preferred is 0.8 to 1.2 equivalents. That is, if the blending ratio of both is out of the above range, sufficient curing reaction does not proceed and the properties of the cured epoxy resin are likely to deteriorate.

  In the present embodiment, a sealing composition using an epoxy resin, a phenolic curing agent and an acrylic resin is particularly preferable. Since these resins have few ionic impurities and high heat resistance, the reliability of the semiconductor element can be ensured. In this case, the mixing ratio of the epoxy resin and the phenolic curing agent is 50 to 1000 parts by weight with respect to 100 parts by weight of the acrylic resin component.

(Other ingredients)
The sealing composition may contain an inorganic filler, other thermosetting resin, a crosslinking agent, and the like in addition to the above components.

(Inorganic filler)
The blending of the inorganic filler makes it possible to improve the thermal conductivity and adjust the storage elastic modulus. Examples of the inorganic filler include silica, clay, gypsum, calcium carbonate, barium sulfate, alumina, beryllium oxide, silicon carbide, silicon nitride, and other ceramics, aluminum, copper, silver, gold, nickel, chromium, lead. And various inorganic powders made of metals such as tin, zinc, palladium, solder, or alloys, and other carbons. These can be used alone or in combination of two or more. Among these, silica, particularly fused silica is preferably used.

  Although the average particle diameter of the inorganic filler is not particularly limited, it is preferably in the range of 0.005 to 10 μm, more preferably in the range of 0.01 to 5 μm, and still more preferably 0.1 to 2. 0.0 μm. When the average particle size of the inorganic filler is less than 0.005 μm, the flexibility of the underfill material is reduced. On the other hand, when the average particle size exceeds 10 μm, the particle size is large with respect to the gap sealed by the underfill material, which causes a decrease in sealing performance. In the present invention, inorganic fillers having different average particle sizes may be used in combination. The average particle size is a value determined by a photometric particle size distribution meter (manufactured by HORIBA, apparatus name: LA-910).

  The blending amount of the inorganic filler is preferably 10 to 400 parts by weight, more preferably 50 to 250 parts by weight with respect to 100 parts by weight of the organic resin component. If the blending amount of the inorganic filler is less than 10 parts by weight, the storage elastic modulus may be lowered and the stress reliability of the package may be greatly impaired. On the other hand, if it exceeds 400 parts by weight, the fluidity of the underfill material 2 may be reduced, and may not be sufficiently embedded in the irregularities of the substrate or semiconductor element, causing voids or cracks.

(Other thermosetting resins)
Examples of other thermosetting resins include amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. These resins can be used alone or in combination of two or more.

(Crosslinking agent)
When the sealing composition of the present embodiment is previously crosslinked to some extent, a polyfunctional compound that reacts with a functional group at the molecular chain end of the polymer is added as a crosslinking agent during production. Good. Thereby, the adhesive property under high temperature can be improved and heat resistance can be improved.

  As the crosslinking agent, polyisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, an adduct of polyhydric alcohol and diisocyanate are more preferable. The addition amount of the crosslinking agent is usually preferably 0.05 to 7 parts by weight with respect to 100 parts by weight of the polymer. When the amount of the cross-linking agent is more than 7 parts by weight, the adhesive force is lowered, which is not preferable. On the other hand, if it is less than 0.05 parts by weight, the cohesive force is insufficient, which is not preferable. Moreover, you may make it include other polyfunctional compounds, such as an epoxy resin, together with such a polyisocyanate compound as needed.

  In addition, another additive can be further mix | blended with a sealing composition suitably as needed. Examples of other additives include flame retardants, silane coupling agents, ion trapping agents, and the like. Examples of the flame retardant include antimony trioxide, antimony pentoxide, brominated epoxy resin, and the like. These can be used alone or in combination of two or more. Examples of the silane coupling agent include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and the like. These compounds can be used alone or in combination of two or more. Examples of the ion trapping agent include hydrotalcites and bismuth hydroxide. These can be used alone or in combination of two or more.

  In the present embodiment, the sealing composition may be colored as necessary. In the sealing composition, the color exhibited by coloring is not particularly limited, but for example, black, blue, red, green and the like are preferable. In coloring, it can be appropriately selected from known colorants such as pigments and dyes.

  In this embodiment, the minimum melt viscosity at 100 to 200 ° C. of the underfill material 2 before thermosetting is preferably 100 Pa · s or more and 20000 Pa · s or less, and is 1000 Pa · s or more and 10,000 Pa · s or less. Is more preferable. By setting the minimum melt viscosity within the above range, the connection member 4 (see FIG. 1A) can easily enter the sealing composition when the sheet-shaped sealing composition and the semiconductor element are bonded to each other. can do. Further, it is possible to prevent generation of voids during electrical connection of the semiconductor element 5 and protrusion of the sealing composition from the space between the semiconductor element 5 and the adherend 6 (FIG. 1D). reference).

  Further, the viscosity at 23 ° C. of the underfill material 2 before thermosetting is preferably 0.01 MPa · s or more and 100 MPa · s or less, and more preferably 0.1 MPa · s or more and 10 MPa · s or less. . When the sealing composition before thermosetting has a viscosity within the above range, the holding property of the semiconductor wafer 3 (see FIG. 1B) during dicing and the handling property during work can be improved.

  Further, the water absorption rate of the underfill material 2 before thermosetting under the conditions of a temperature of 23 ° C. and a humidity of 70% is preferably 1% by weight or less, and more preferably 0.5% by weight or less. When the sealing composition has the water absorption rate as described above, moisture absorption into the sealing composition is suppressed, and generation of voids when the semiconductor element 5 is mounted can be more efficiently suppressed. The lower limit of the water absorption rate is preferably as small as possible, substantially 0% by weight is preferable, and 0% by weight is more preferable.

  Although the thickness (total thickness in the case of a multilayer) of the sheet-shaped sealing composition is not particularly limited, considering the strength of the sealing composition and the filling property of the space between the semiconductor element 5 and the adherend 6. It may be about 10 μm or more and 100 μm or less. Note that the thickness of the underfill material 2 may be appropriately set in consideration of the gap between the semiconductor element 5 and the adherend 6 and the height of the connection member.

  The sheet-like sealing composition is preferably formed on the separator 1 as shown in FIG. The separator 1 has a function as a strength base material of the sealing composition 2. As the separator 2, the base material of the separator may be used as it is, or the surface of the base material may be used after being treated with a release agent.

  As a material for forming the separator substrate, for example, low density polyethylene, linear polyethylene, medium density polyethylene, high density polyethylene, ultra low density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, Polyolefin such as polymethylpentene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester (random, alternating) copolymer, ethylene-butene copolymer Polymer, ethylene-hexene copolymer, polyester such as polyurethane, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyimide, polyetheretherketone, polyimide, polyetherimide, polyamide, all Examples include aromatic polyamide, polyphenyl sulfide, aramid (paper), glass, glass cloth, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulosic resin, silicone resin, metal (foil), glassine paper, etc. .

  Examples of the material for the base material include polymers such as cross-linked resins of the resins listed above. The plastic film may be used unstretched or may be uniaxially or biaxially stretched as necessary. According to the sealing sheet to which heat shrinkability is imparted by stretching treatment or the like, the adhesive area between the base material 1 and the sealing composition is reduced by thermally shrinking the base material 1 after dicing, and the semiconductor chip is recovered. Can be facilitated.

  As the release agent, release agents such as fluorine-based release agents and long-chain alkyl acrylate release agents can be used.

(Method for producing sheet-shaped sealing composition)
The method for producing a sheet-shaped sealing composition according to this embodiment includes a step of forming the sealing composition 2 on the separator 1.

  Examples of the method for forming the substrate of the separator 1 include a calendar film forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a co-extrusion method, and a dry lamination method. it can. The material shown above may be used as the base material. As needed, you may perform the process by the above-mentioned peeling agent to the surface at the side of the sheet-like sealing composition in the said base material.

  As a process of forming the sheet-shaped sealing composition 2, for example, a process of forming a coating layer by applying a resin composition solution that is a constituent material of the sheet-shaped sealing composition on the separator 1 is performed. The method of performing the process of drying the said application layer is mentioned. The resin composition solution can be prepared by dissolving and dispersing the components of the sealing composition described above in an appropriate solvent (for example, methyl ethyl ketone).

  The coating method of the resin composition solution is not particularly limited, and examples thereof include a coating method using a comma coating method, a fountain method, a gravure method, and the like. What is necessary is just to set suitably as coating thickness so that the thickness of the sealing composition finally obtained by drying an application layer may become in the range shown above. Furthermore, it does not specifically limit as a viscosity of a resin composition solution, 400-2500 mPa * s is preferable in 25 degreeC, and 800-2000 mPa * s is more preferable.

  What is necessary is just to perform drying of the said coating layer by throwing into a common heating furnace etc. In that case, you may spray a drying wind on a coating layer.

  The drying time is appropriately set according to the coating thickness of the resin composition solution, and is usually in the range of 1 to 5 minutes, preferably 2 to 4 minutes. When the drying time is less than 1 min, the curing reaction does not proceed sufficiently, and there are a large amount of unreacted curing components and remaining solvent, which may cause problems of outgas and voids in the subsequent process. On the other hand, if it exceeds 5 minutes, the curing reaction proceeds too much, and the fluidity and embedding property of the bumps of the semiconductor wafer may be reduced.

  A drying temperature is not specifically limited, Usually, it sets within the range of 70-160 degreeC. However, in the present invention, it is preferable that the drying temperature is increased stepwise as the drying time elapses. Specifically, for example, it is set within a range of 70 ° C. to 100 ° C. in the initial stage of drying (1 min or less immediately after drying), and is set within a range of 100 to 160 ° C. in the late stage of drying (over 1 min and 5 min or less). . Thereby, generation | occurrence | production of the pinhole on the surface of an application layer which arises when a drying temperature is raised rapidly immediately after coating can be prevented.

  Furthermore, the separator may be bonded to the other surface of the sheet-shaped sealing composition, and this may be used as a protective film for the sealing sheet, and peeled off when bonded to a semiconductor wafer or the like. Thereby, the sheet-like sealing composition which concerns on this embodiment can be manufactured.

<Method for Manufacturing Semiconductor Device>
The method for manufacturing a semiconductor device of the present invention includes a bonding step of bonding a surface of a semiconductor wafer on which a connection member is formed and the sheet-shaped sealing composition, and dicing the semiconductor wafer to form the sheet-shaped sealing composition. A dicing step of forming a semiconductor element with an object, and the semiconductor element and the adherend through the connecting member while filling a space between the adherend and the semiconductor element with the sheet-shaped sealing composition And a connecting step of electrically connecting the two. Hereinafter, position embodiments of the manufacturing method will be described.

[Lamination process]
In the bonding step, the surface of the semiconductor wafer 3 on which the connection member 4 is formed and the sheet-shaped sealing composition 2 are bonded together (see FIG. 2A).

(Semiconductor wafer)
As the semiconductor wafer 3, a plurality of connection members 4 may be formed on one surface 3a (see FIG. 2A), and connection members may be formed on both surfaces 3a and 3b of the semiconductor wafer 3. (Not shown). The material of the connection member such as a bump or a conductive material is not particularly limited. For example, a tin-lead metal material, a tin-silver metal material, a tin-silver-copper metal material, a tin-zinc metal material, Examples thereof include solders (alloys) such as a tin-zinc-bismuth metal material, a gold metal material, and a copper metal material. The height of the connecting member is also determined according to the application, and is generally about 10 to 60 μm. Of course, the height of each connection member in the semiconductor wafer 3 may be the same or different.

  When connection members are formed on both surfaces of the semiconductor wafer, the connection members may or may not be electrically connected to each other. Examples of the electrical connection between the connection members include a connection through a via called a TSV format.

In this embodiment, it is preferable that the height X (μm) of the connection member of the semiconductor wafer and the thickness Y (μm) of the sealing composition satisfy the following relationship.
0.5 ≦ Y / X ≦ 2

  When the height X (μm) of the connecting member and the thickness Y (μm) of the sealing composition satisfy the above relationship, the space between the semiconductor element and the adherend can be sufficiently filled. it can. In addition, excessive protrusion of the sealing composition from the space can be prevented, whereby contamination of the semiconductor element by the sealing composition can be prevented. In addition, when the height of each connection member differs, the height of the highest connection member is used as a reference.

(Lamination)
As shown in FIG. 2 (a), first, a separator arbitrarily provided on the sheet-shaped sealing composition 2 is appropriately peeled off to form a surface on which the connection member 4 of the semiconductor wafer 3 is formed (connection member formation). Surface) 3a and the sealing composition are opposed to each other, and the sealing composition 2 and the semiconductor wafer 3 are bonded together (mounting step).

  The method of bonding is not particularly limited, but a method by pressure bonding is preferable. The crimping is usually performed by a known pressing means such as a crimping roll while applying a pressure of 0.1 to 1 MPa, more preferably 0.3 to 0.7 MPa. Under the present circumstances, you may make it press-fit, heating at about 40-100 degreeC. Moreover, in order to improve adhesiveness, it is also preferable to press-fit under reduced pressure (1-1000 Pa).

[Dicing process]
In the dicing step, the semiconductor wafer 5 with the sealing composition 2 is formed by dicing the semiconductor wafer 3 as shown in FIG. By passing through a dicing process, the semiconductor wafer 3 is cut into a predetermined size and divided into pieces (small pieces), and a semiconductor chip (semiconductor element) 5 is manufactured. The semiconductor chip 5 obtained here is integrated with the sealing composition 2 cut into the same shape. Dicing is performed according to a conventional method from the surface 3b opposite to the surface 3a to which the sealing composition of the semiconductor wafer 3 is bonded. The alignment of the cut portion can be performed by image recognition using direct light, indirect light, or infrared (IR).

  In this step, for example, a cutting method called full cut for cutting up to the sealing composition can be employed. It does not specifically limit as a dicing apparatus used at this process, A conventionally well-known thing can be used. Moreover, since the semiconductor wafer is bonded and fixed with excellent adhesion by the sealing composition, chip chipping and chip jump can be suppressed, and damage to the semiconductor wafer can also be suppressed. Since the sealing composition is formed of a resin composition containing an epoxy resin, even if the sealing composition is cut by dicing, it suppresses or prevents the adhesive composition from protruding on the cut surface. can do. As a result, it is possible to suppress or prevent the cut surfaces from reattaching (blocking), and the pickup described later can be performed more satisfactorily.

  In addition, when expanding the separator 1 following a dicing process, this expansion can be performed using a conventionally well-known expanding apparatus. The expanding device has a donut-shaped outer ring that can push the separator 1 downward through a dicing ring, and an inner ring that supports the separator 1 with a smaller diameter than the outer ring. By this expanding process, it is possible to prevent adjacent semiconductor chips from coming into contact with each other and being damaged in a pickup process described later.

[Pickup process]
In order to collect the semiconductor chip 5 with the sheet-like sealing composition 2, as shown in FIG. 2C, the semiconductor chip 5 with the sealing composition 2 is picked up and sealed with the semiconductor chip 5. The laminate A with the composition 3 is peeled off from the separator 1.

  The pickup method is not particularly limited, and various conventionally known methods can be employed. For example, the method of pushing up each semiconductor chip from the base material side of a laminated film with a needle, and picking up the pushed-up semiconductor chip with a pickup device, etc. are mentioned. The picked-up semiconductor chip 5 constitutes the laminate A together with the sealing composition bonded to the surface 3a.

[Connection process]
In the connecting step, the semiconductor element and the adherend are electrically connected via the connecting member while filling the space between the adherend and the semiconductor element with the sealing composition (a so-called mounting step, FIG. 2 (d). )reference). Specifically, the semiconductor chip 5 of the stacked body A is fixed to the adherend 6 according to a conventional method with the connection member forming surface 3a of the semiconductor chip 5 facing the adherend 6. For example, bumps (connection members) 4 formed on the semiconductor chip 5 are brought into contact with a bonding conductive material 7 (solder or the like) attached to the connection pads of the adherend 6 while pressing the conductive material. By melting, the electrical connection between the semiconductor chip 5 and the adherend 6 can be secured, and the semiconductor chip 5 can be fixed to the adherend 6. At this time, the sheet-shaped sealing composition 2 contains a predetermined carboxyl group-containing compound, and since the reaction with the epoxy resin is suppressed by heat during mounting, the flux function can be sufficiently exhibited. . Thus, since the sealing composition 2 is affixed to the connection member formation surface 3a of the semiconductor chip 5, the semiconductor chip 5 and the adherend are simultaneously connected to the semiconductor chip 5 and the adherend 6 at the same time. The space between the body 6 can be efficiently filled. By passing through this connection step, the sealing composition is cured.

  As the adherend 6, other semiconductor elements can be used in addition to various substrates such as a lead frame and a circuit substrate (such as a wiring circuit substrate). The material of such a substrate is not particularly limited, and examples thereof include a ceramic substrate and a plastic substrate. Examples of the plastic substrate include an epoxy substrate, a bismaleimide triazine substrate, a polyimide substrate, and a glass epoxy substrate.

  In the connection step, one or both of the connection member and the conductive material are melted to connect the bumps 4 on the connection member forming surface 3a of the semiconductor chip 5 and the conductive material 7 on the surface of the adherend 6. However, the temperature at the time of melting of the bump 4 and the conductive material 7 is usually about 220 ° C. (for example, 160 ° C. to 300 ° C.). Since the sealing composition according to this embodiment is formed of an epoxy resin or the like, it has heat resistance that can withstand high temperatures in this mounting process.

[Sealing process]
Next, a sealing step may be performed in order to protect the entire semiconductor device 20 including the mounted semiconductor chip 5. The sealing step is performed using a sealing resin. Although it does not specifically limit as sealing conditions at this time, Usually, the thermosetting of the sealing resin is performed by heating at 175 ° C. for 60 seconds to 90 seconds, but the present invention is not limited thereto, For example, it can be cured at 165 ° C. to 185 ° C. for several minutes.

  The sealing resin is not particularly limited as long as it is an insulating resin (insulating resin), and can be appropriately selected from sealing materials such as known sealing resins. Is more preferable. As sealing resin, the resin composition containing an epoxy resin etc. are mentioned, for example. Examples of the epoxy resin include the epoxy resins exemplified above. Moreover, as a sealing resin by the resin composition containing an epoxy resin, in addition to an epoxy resin, a thermosetting resin other than an epoxy resin (such as a phenol resin) or a thermoplastic resin may be included as a resin component. Good. In addition, as a phenol resin, it can utilize also as a hardening | curing agent of an epoxy resin, As such a phenol resin, the phenol resin illustrated above etc. are mentioned.

[Semiconductor device]
Next, a semiconductor device obtained using the sheet-shaped sealing composition will be described with reference to the drawings (see FIG. 2D). In the semiconductor device 20 according to the present embodiment, the semiconductor element 5 and the adherend 6 are connected via the bump (connection member) 4 formed on the semiconductor element 5 and the conductive material 7 provided on the adherend 6. Are electrically connected. Further, the sealing composition 2 is disposed between the semiconductor element 5 and the adherend 6 so as to fill the space. Since the semiconductor device 20 is obtained by the above manufacturing method using the sealing composition 2, the bonding between the bumps 4 of the semiconductor element 5 and the adherend 6 is favorably performed. Therefore, the surface protection of the semiconductor element 5 and the filling of the space between the semiconductor element 5 and the adherend 6 are at a sufficient level, and the semiconductor device 20 can exhibit high reliability.

  Hereinafter, preferred embodiments of the present invention will be described in detail by way of example. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the present invention only to those unless otherwise specified. The term “parts” means parts by weight.

[Example 1]
4.74 parts of naphthalene type epoxy resin having an epoxy equivalent of 142 g / eq (manufactured by DIC, product name: HP4032D), phenol novolac type epoxy resin having an epoxy equivalent of 169 g / eq (product name: EPPN501HY) 1.19 parts, phenol equivalent of 175 g / eq phenol novolak resin (Maywa Kasei Co., Ltd., product name: MEH-7800S) 7.05 parts, weight average molecular weight 900,000 butyl acrylate-ethyl acrylate- Acrylonitrile copolymer (manufactured by Nagase ChemteX Corporation, product name: Teisan Resin SG-28GM) 1.8 parts, p-anisic acid (pKa = 4.5), triphenylphosphine as a curing accelerator ( 0.18 parts of Shikoku Kasei Kogyo Co., Ltd.) is dissolved in methyl ethyl ketone, and an inorganic filler (Adma Co., Ltd.) is dissolved. Tex Inc., product name: SE2050MC, with the addition of average particle size 0.5 [mu] m) 10.47 parts, to prepare a solution of the resin composition solid concentration of 40 wt%.

  The resin composition solution was applied on a release treatment film (separator) made of a polyethylene terephthalate film having a thickness of 50 μm after the silicone release treatment, and then dried at 130 ° C. for 2 minutes, whereby a thickness of 55 μm was obtained. A sheet-shaped sealing composition was produced.

[Example 2]
A sheet-shaped sealing composition was prepared in the same manner as in Example 1 except that p-dimethylaminobenzoic acid (pKa = 4.9) was used instead of p-anisic acid.

[Example 3]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that octanedioic acid (pKa ₁ = 4.5) was used instead of p-anisic acid.

[Example 4]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that dodecanedioic acid (pKa ₁ = 5.0) was used instead of p-anisic acid.

[Example 5]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that oleic acid (pKa = 5.0) was used instead of p-anisic acid.

[Example 6]
A sheet-shaped sealing composition was prepared in the same manner as in Example 1 except that 1,2-cyclohexanedicarboxylic acid (pKa ₁ = 4.4) was used instead of p-anisic acid.

[Example 7]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that 2-phenoxybenzoic acid (pKa = 3.5) was used instead of p-anisic acid.

[Example 8]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that 2-phenylbenzoic acid (pKa = 3.5) was used instead of p-anisic acid.

[Comparative Example 1]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that 2,6-dihydroxybenzoic acid (pKa = 1.2) was used instead of p-anisic acid.

[Comparative Example 2]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that 2-nitrobenzoic acid (pKa = 2.5) was used instead of p-anisic acid.

[Comparative Example 3]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that phenol (pKa = 9.9) was used instead of p-anisic acid.

[Comparative Example 4]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that p-anisic acid was not added.

[Comparative Example 5]
A sheet-shaped sealing composition was produced in the same manner as in Example 1 except that the butyl acrylate-ethyl acrylate-acrylonitrile copolymer was not added.

(Evaluation of bump bonding)
A semiconductor chip with a single-sided bump having a bump formed on one side is prepared, and the sheet-shaped sealing composition produced in the examples and comparative examples is formed on the surface of the semiconductor chip with the single-sided bump on which the bump is formed. Pasted together. The following was used as a semiconductor chip with a single-sided bump. The bonding conditions are as follows. The ratio (Y / X) of the thickness Y (= 65 μm) of the sheet-shaped sealing composition to the bump height X (= 65 μm) was 1.0.

(Evaluation of flexibility of sheet-shaped sealing composition)
The sheet-like sealing composition obtained as described above was allowed to stand for 1 week under conditions of a temperature of 25 ° C. and a humidity of 70%, and then folded at 90 degrees to indicate that no crack was generated. The thing which generate | occur | produced was evaluated as "x".

<Semiconductor chip with single-sided bump>
Size: 10mm square Thickness: 0.5mm (500μm)
Bump height: 65μm
Number of bumps: 1960
Bump material: Sn-Ag-Cu solder

<Bonding conditions>
Pasting device: Product name “DSA840-WS” manufactured by Nitto Seiki Co., Ltd. Pasting speed: 10 mm / min
Pasting pressure: 0.5 MPa
Stage temperature when pasting: 75 ° C
Degree of vacuum at the time of pasting: 1000 Pa

  Next, following the thermocompression condition 1 below, a connection process is performed under thermocompression condition 2, and the semiconductor chip is thermocompression bonded to the copper plate with the bump forming surface of the semiconductor chip and the copper plate having a thickness of 200 μm facing each other. Both were joined.

<Thermocompression condition 1>
Flip chip bonder: Product name “FCB-3” manufactured by Panasonic Heating temperature: 185 ° C.
Load: 6kg (58.8N)
Holding time: 20 seconds

<Thermocompression condition 2>
Flip chip bonder: Product name “FCB-3” manufactured by Panasonic Heating temperature: 3000 ° C.
Load: 1kg (9.8N)
Holding time: 10 seconds

  Evaluation of bump bondability was performed according to the following procedure. The semiconductor chip with bumps is peeled off from the copper plate, and the area bonded to the bumps on the copper plate is observed to recognize how much the solder that forms the bumps has migrated to the bonding area on the copper plate. It confirmed using the apparatus (Hamamatsu Photonics company make, brand name "C9597-11"). The case where solder remains on almost the entire surface of the joining region (when the copper plate is viewed in plan, the solder remains in 80% or more of the area within the maximum outer edge (circular shape) of the joining region in the joined state) The case where “◯” was less than 80% was evaluated as “×”. The results are shown in Table 1.

  As can be seen from Table 1, in the sheet-shaped sealing composition according to the example, solder remained on almost the entire surface of the bonding region, and good bump bonding property was confirmed. On the other hand, in Comparative Examples 1 to 4, the solder hardly remained in the bonding region, or even if it remained, only a part thereof was present, and the bump bonding property was insufficient and the connection reliability was low. In Comparative Example 5, the bump bondability was good, but stable flexibility was not shown.

DESCRIPTION OF SYMBOLS 1 Separator 2 Sheet-like sealing composition 3 Semiconductor wafer 3a The surface in which the connection member of the semiconductor wafer was formed 3b The surface on the opposite side to the surface in which the connection member of the semiconductor wafer was formed 4 Bump (connection member)
5 Semiconductor chip (semiconductor element)
6 Substrate 7 Conducting material 20 Semiconductor device

Claims (9)

A thermoplastic resin having a weight average molecular weight of 100,000 or more;
Epoxy resin,
A curing accelerator;
A sheet-shaped sealing composition comprising: a carboxyl group-containing compound having a pKa of 3.5 or more. The carboxyl group-containing compound is
An aromatic carboxylic acid having at least one substituent selected from the group consisting of an alkyl group, an alkoxy group, an aryloxy group, an aryl group, and an alkylamino group in the molecule, and one or more carboxyl groups in the molecule The sheet-shaped sealing composition according to claim 1, which is at least one selected from the group consisting of aliphatic carboxylic acids having 8 or more carbon atoms.   The aromatic carboxylic acid is a benzoic acid derivative in which at least one hydrogen atom in the 2-position, 4-position and 6-position is independently substituted with an alkyl group, alkoxy group, aryloxy group, aryl group or alkylamino group The sheet-like sealing composition according to claim 2.   The sheet-shaped sealing composition according to claim 3, wherein the benzoic acid derivative is a benzoic acid derivative in which a hydrogen atom at the 2-position or the 4-position is substituted with a methoxy group, a phenoxy group, a phenyl group, or a dimethylamino group.   The sealing resin sheet according to claim 3 or 4, wherein the benzoic acid derivative does not contain a hydroxyl group.   The encapsulating resin sheet according to claim 2, wherein the aliphatic carboxylic acid is a chain aliphatic dicarboxylic acid having 8 to 12 carbon atoms or an alicyclic dicarboxylic acid.   The sheet-like sealing composition according to any one of claims 1 to 6, further comprising a phenolic curing agent.   The sheet-shaped sealing composition according to any one of claims 1 to 7, wherein the thermoplastic resin is an acrylic resin. A laminating step of laminating the surface on which the connecting member of the semiconductor wafer is formed and the sheet-shaped sealing composition according to any one of claims 1 to 8,
A dicing step of dicing the semiconductor wafer to form a semiconductor element with the sheet-shaped sealing composition;
A connection step of electrically connecting the semiconductor element and the adherend through the connection member while filling a space between the adherend and the semiconductor element with the sheet-shaped sealing composition. A method for manufacturing a semiconductor device.

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