JP4176619B2 - Flip chip mounting side fill material and semiconductor device - Google Patents

Description

  The present invention relates to a side-fill material for flip chip mounting which is used when manufacturing a semiconductor device and has no bleed and excellent in thermal shock resistance.

  In recent years, surface mounting, that is, bare chip mounting, has been adopted as a semiconductor mounting method, instead of the conventional pin insertion type, as electric devices have become smaller, lighter, and higher performance. Various methods have been proposed and implemented for this bare chip mounting, and a main example is flip chip (FC) mounting. In FC mounting, several to several thousand electrodes called bumps having a height of about 10 to 100 μm are formed on the wiring pattern surface of a semiconductor chip such as an LSI chip, and the bumps and the bumps are formed on the substrate. In this method, the electrodes are joined using, for example, a high-temperature reflow furnace using a conductive paste, solder, or the like.

  In addition, the sealing method using the sealing material in the FC mounting is for the purpose of sealing a gap of about 20 to 40 μm between the substrate and the semiconductor chip derived from the bump height of the LSI chip. There are two methods, an underfill type in which a sealing material is filled in the gap and a side fill type in which only the periphery of the chip is sealed. Both of them have advantages and disadvantages. For example, if the internal elements of the device are optically configured, or if the wiring structure is dense, the gap is not affected. The side fill type is more suitable than the fill type.

  In the underfill type, since the sealing and filling process of the gap portion requires a relatively long time, the side fill type is more preferable from the viewpoint of process and productivity. (Hereinafter, the sealing material used in the side fill type method is referred to as “side fill material”.)

However, in the case of the side fill type, it is pointed out that there is a problem that it is difficult to control the penetration of the side fill material into the gap, and the liquid component derived from the side fill material bleeds after sealing. The countermeasure was desired. Furthermore, compared with the underfill type, the side fill type has a structure in which the contact area between the side fill material and the substrate is smaller and more susceptible to thermal shock because of the usage pattern or sealing structure of the side fill material. Therefore, the cured product of the side fill material is required to have stress relaxation performance in order to suppress the occurrence of cracks and the like.
In addition, patent document 1-patent document 4 are mentioned as a related prior art document of the said description matter.

JP-A-11-163513 JP 9-260534 A Japanese Patent Laid-Open No. 10-321666 JP 2001-77246 A

  In view of the above circumstances, the present invention can suppress bleeding of the liquid component derived from the side fill material, and control the penetration of the side fill material into the gap between the substrate and the semiconductor chip by controlling it to an appropriate fixed range. An object of the present invention is to provide a flip-chip side-fill material that provides a highly reliable semiconductor product that has high sealing performance and is excellent in crack resistance due to stress relaxation performance of a cured product.

As a result of intensive studies to achieve the above object, the present inventor was able to complete the present invention.
That is, the present invention
(A) Liquid epoxy resin,
(B) a curing agent,
(C) an alkyl methacrylate copolymer,
(D) an inorganic filler having a content of particles having a particle size of 45 μm or more of 1% by mass or less and an average particle size of 0.5 μm or more and less than 5 μm;
(E) An inorganic filler having an average particle diameter of 0.01 to 0.10 μm, which has been surface-treated with a non-reactive organosilicon compound, and (F) a modified silicone resin, and a viscosity at 25 ° C. of 100 Pa. Provided is a side-fill material for flip chip mounting of a semiconductor device including a substrate and a semiconductor chip mounted on the substrate, which includes a liquid epoxy resin composition of s or more and less than 1000 Pa · s, and a semiconductor device. .
(Hereinafter, the “liquid epoxy resin composition” may be referred to as “the liquid epoxy resin composition of the present invention”.)

  The side-fill material for flip chip mounting according to the present invention can suppress generation of bleed of a liquid component and can appropriately enter and fill a gap between the substrate and the semiconductor chip. And it can prevent the occurrence of cracks due to thermal expansion and contraction of the cured product and peeling from the substrate, etc., and is good even under conditions of high temperature and high humidity and severe conditions such as a thermal shock test. Since the sealing characteristics can be exhibited, a highly reliable semiconductor device can be provided.

Hereinafter, the present invention will be described in more detail.
[Liquid epoxy resin composition]
[(A) Liquid epoxy resin]
The liquid epoxy resin of the component (A) used in the liquid epoxy resin composition of the present invention is a component that imparts curability to the side fill material, and has two or more epoxy groups in one molecule. The molecular structure, molecular weight and the like are not particularly limited as long as they satisfy the condition that they themselves are liquid at room temperature, and all known epoxy resins can be used.

  Examples of the component (A) include bisphenol type epoxy resins such as bisphenol A type epoxy resins and bisphenol F type epoxy resins; alicyclic epoxy resins; phenol novolac type epoxy resins and novolak type epoxy resins such as cresol novolak type epoxy resins. Resin; Triphenolalkane type epoxy resin such as triphenolmethane type epoxy resin and triphenolpropane type epoxy resin; Phenol aralkyl type epoxy resin, Biphenyl aralkyl type epoxy resin, Stilbene type epoxy resin, Naphthalene type epoxy resin, Biphenyl type epoxy resin And cyclopentadiene type epoxy resin. These liquid epoxy resins can be used singly or in combination of two or more.

  Among these, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin are particularly preferable. Furthermore, an epoxy resin represented by the following structure can also be preferably used.

  Further, the total chlorine content contained in the liquid epoxy resin of the component (A) is preferably 1,500 ppm or less, particularly 1,000 ppm or less. Moreover, it is desirable that the amount of chlorine ions extracted under conditions of 100 ° C. × 20 hours in water containing 50% by mass of a liquid epoxy resin is 10 ppm or less. If the total chlorine content and the amount of extracted chlorine ions are not more than the upper limit, the moisture resistance is good and the reliability of the semiconductor device is not impaired.

[(B) Curing agent]
The component (B) used in the liquid epoxy resin composition of the present invention is a component for curing the liquid epoxy resin as the component (A). As the component (B), two or more functional groups capable of reacting with the epoxy group in the component (A), for example, a monovalent group such as a phenolic hydroxyl group and an amino group, As long as it is a substantially divalent group such as an acid anhydride group, it may be a compound having one or more thereof, and the molecular structure, molecular weight, etc. are not particularly limited, and all known epoxy resin curing agents are used. be able to.

  Examples of the component (B) include phenol resins having at least two phenolic hydroxyl groups in one molecule. More specifically, novolak type phenol resins such as phenol novolak resin and cresol novolak resin; paraxylylene Modified novolak resins, metaxylylene modified novolak resins, orthoxylylene modified novolak resins and other xylylene modified novolak resins; bisphenol A type resins, bisphenol F type resins and other bisphenol type phenol resins; biphenyl type phenol resins, resol type phenol resins, phenol aralkyls Type resins, biphenyl aralkyl type resins and other phenol resins; triphenol methane type resins, triphenol alkane type resins such as triphenol propane type resins, and their polymers Lumpur resin; naphthalene ring-containing phenolic resins, dicyclopentadiene-modified phenol resin; are both available.

  Examples of the case where the component (B) is an amine include, for example, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, bis (4-amino-3-methylzincyclohexyl) methane, diaminozine cyclohexylmethane, Aliphatic amines such as bis (aminomethyl) cyclohexane; metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, 3,3′-diethyl-4,4′-diaminodiphenylmethane, 3,3 ′, 5,5′-tetraethyl- And aromatic amines such as 4,4′-diaminodiphenylmethane.

  Examples of the case where the component (B) is an acid anhydride include, for example, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, pyrometic dianhydride, 3,4-dimethyl -6- (2-Methyl-1-propenyl) -4-cyclohexane-1,2-dicarboxylic anhydride, 1-methyl-4- (1-methylethyl) -bicyclo [2.2.2] oct-5 -Ene-2,3-dicarboxylic anhydride, benzophenone tetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether Preferred are anhydrides, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, etc. Or having one or two aliphatic rings or aromatic rings in the molecule and one or two acid anhydride groups (that is, —CO—O—CO— groups) having 4 to 4 carbon atoms. 25, preferably about 8 to 20 acid anhydrides are suitable.

As the component (B), carboxylic acid hydrazides such as dicyandiamide, adipic acid hydrazide, and isophthalic acid hydrazide can also be used.
The curing agent for component (B) can be used singly or in combination of two or more.

  The amount of component (B) used is such that the liquid epoxy resin composition used as the side-fill material for flip chip mounting of the present invention can be sufficiently cured to a desired degree under normal curing conditions. In addition, the cured product becomes brittle due to excessive curing, cracks do not occur during reflow or temperature cycling, and no functional group derived from the curing agent remains after curing, and the glass transition point of the cured product, sealing There is no particular limitation as long as the condition that the properties such as stopping property or adhesiveness are not impaired is satisfied. For example, the amount of a functional group such as phenolic hydroxyl group, amino group, acid anhydride group, etc. contained in the curing agent with respect to 1 mol of the epoxy group in the component (A) (in the case of a polyvalent functional group) Is converted as having a plurality of monovalent groups), but it is usually preferable to use a curing agent in an amount of about 0.8 to 1.2 mol, preferably about 0.9 to 1.1 mol.

  When the post-modified silicone resin has an epoxy group, the amount is based on the total amount of the epoxy group in the component (A) and the epoxy group in the post-modified silicone resin. When the post-modified silicone resin has a phenolic hydroxyl group, the amount is based on the total amount of the functional group in the component (B) and the phenolic hydroxyl group in the post-modified silicone resin.

[Curing accelerator]
In the liquid epoxy resin composition of the present invention, a curing accelerator can be used in combination with the curing agent of the component (B) as necessary. The curing accelerator is not particularly limited as long as it accelerates the curing reaction, and all known ones can be used. Examples thereof include imidazole compounds, tertiary amine compounds, and organic phosphorus compounds. Can do.

  Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2,4-dimethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 1,2-diethylimidazole. 2-phenyl-4-methylimidazole, 2,4,5-triphenylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methyl Imidazole, 1-cyanoethyl-2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-allyl-4,5-diphenylimidazole, 2-phenyl-4- Methyl-5-hy B carboxymethyl and imidazole.

  Among these, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-ethylimidazole, 1 , 2-dimethylimidazole, 1,2-diethylimidazole, 2,4-dimethylimidazole and 2-phenyl-4-methylimidazole are preferred.

  Examples of the tertiary amine compound include amine compounds having an alkyl group or an aralkyl group as a substituent bonded to a nitrogen atom such as triethylamine, benzyldimethylamine, benzyltrimethylamine, and α-methylbenzyldimethylamine; 1,8 -Diazabicyclo [5.4.0] undecene-7 and cycloamidine compounds such as phenol salts, octylates and oleates thereof and salts thereof with organic acids; cycloamidine compounds such as compounds represented by the following structural formula And a salt or complex salt of quaternary boron compound.

Examples of organic phosphorus compounds include tributylphosphine, triphenylphosphine, tri (methylphenyl) phosphine, tri (nonylphenyl) phosphine, tri (methoxyphenyl) phosphine, diphenyltolylphosphine, triphenylphosphine / triphenylborane. And quaternary phosphonium salts such as tetraphenylphosphonium and tetraphenylborate.
These curing accelerators can be used singly or in combination of two or more.

  In addition, when using a hardening accelerator, a hardening acceleration effect is exhibited and from a viewpoint that the storage stability of a liquid epoxy resin composition is not impaired, 100 parts by weight of the liquid epoxy resin of the component (A) On the other hand, the amount is usually 10 parts by mass or less, preferably 0.01 to 10 parts by mass, particularly 0.5 to 5 parts by mass.

[(C) Alkyl methacrylate copolymer]
The flip-chip side fill material comprising the liquid epoxy resin composition of the present invention is heated to a temperature higher than room temperature and lower than the curing temperature, for example, a temperature of 50 to 100 ° C., and once in a B-stage state (ie, Solidified semi-cured state), and then heat-treated to a sufficient temperature and finally cured, so that the liquid component bleed in the curing process and the liquid component bleed from the cured product after sealing It is effective for suppressing the occurrence.

  In order to make the liquid epoxy resin composition of the present invention in the B-stage state as described above, the non-reactive organosilicon compound of the component (E) described below is used as the component (C). It is necessary to mix | blend with the inorganic filler surface-treated in.

Examples of the alkyl methacrylate copolymer as the component (C) include ZEON F340A, F340, F345, and F351 (trade names, manufactured by Nippon Zeon Co., Ltd.).
This component (C) can be used alone or in combination of two or more. The amount used is not particularly limited as long as it is sufficient to form a B-stage state in which each compounding component is uniformly dispersed from the liquid epoxy resin composition of the present invention. It is 1-5 mass% normally with respect to the whole quantity of the liquid epoxy resin composition of invention, Preferably it is 2-3 mass%.

[(D) Inorganic filler]
The inorganic filler of component (D) used in the liquid epoxy resin composition of the present invention is used to reduce the coefficient of thermal expansion of the resulting cured product and to the gap between the substrate and the semiconductor chip of the present invention. It is a component mix | blended in order to control the penetration | invasion of this.
As the component (D), conventionally known various inorganic fillers can be used. For example, fused silica, crystalline silica, alumina, boron nitride, aluminum nitride, silicon nitride, magnesia, magnesium silicate. Etc. These can be used singly or in combination of two or more. Further, as the component (D), a spherical one is preferable from the viewpoint of securing the fluidity of the liquid resin composition of the present invention.

  In the present invention, the average particle size of the component (D) is required to be 0.5 μm or more and less than 5 μm, and preferably 1 to 3 μm. When the average particle size is 5 μm or more, it becomes difficult to control the penetration of the side fill material of the present invention into the gap between the substrate and the semiconductor chip mounted on the substrate within an appropriate fixed range. When the average particle size is less than 0.5 μm, the viscosity of the epoxy resin composition becomes high and the fluidity is lowered. And when the fluidity | liquidity of an epoxy resin composition falls, when mounting and applying a sidefill material using a syringe etc., it will become inferior to dispensing property, and there exists a possibility of causing trouble on operation | work.

Further, the content of particles having a particle diameter of 45 μm or more contained in the component (D) needs to be 1% by mass or less, preferably 0.5% by mass or less. If the content exceeds 1% by mass, the tip nozzle such as a syringe may be clogged during dispensing, which may hinder work.
In addition, the said average particle diameter and particle diameter can be measured by the particle size distribution measurement by a laser beam diffraction method, for example. Moreover, an average particle diameter can be calculated | required as a median diameter.

  The amount of component (D) used is usually 30 to 65% by mass, preferably 35 to 60% by mass, based on the total amount of the liquid epoxy resin composition of the present invention. When the amount used is too small, the thermal expansion coefficient of the resulting cured product increases, and in some cases, peeling from the semiconductor chip, cracks, etc. are induced in the thermal shock test. Conversely, if the amount used is too large, the viscosity becomes too high to make it difficult to obtain a liquid epoxy resin composition, and the side fill material into the gap between the substrate and the semiconductor chip mounted on the substrate It becomes difficult to control the intrusion of the light within a certain range. For example, there is a possibility that the side fill material cannot penetrate into the electrode on the inner side of about 500 μm from the peripheral edge of the semiconductor device, resulting in unfilling.

[(E) Inorganic filler surface-treated with non-reactive organosilicon compound]
The inorganic filler surface-treated with the non-reactive organosilicon compound (E) used in the liquid epoxy resin composition of the present invention is uniformly dispersed in the matrix of the liquid epoxy resin composition, and the above (C As described above, it is a component that is blended to suppress bleed of the liquid component in the curing process and generation of bleed of the liquid component from the cured product after sealing. . The non-reactive organosilicon compound means a compound that does not have a functional group involved in the curing reaction.

Further, the component (E), the inorganic filler has an average particle size of 0.01 to 0.15 [mu] m is required to be one that is surface treated with a non-reactive organic silicon compound. The surface treatment is performed in order to suppress the bleed and improve the dispersibility of the inorganic filler. When the average particle size of the inorganic filler is less than 0.01 μm, the viscosity of the epoxy resin composition increases, and a liquid product may not be obtained or the liquid state may not be maintained. Further, if it exceeds 0.15 μm, the occurrence of bleeding of the liquid component may not be suppressed, and the shape of the sealed product before curing is maintained when the liquid epoxy resin composition of the present invention is applied as a side fill material. There is a problem that becomes difficult.

Examples of the inorganic filler having an average particle size of 0.01 to 0.15 μm include fumed silica such as Aerosil 130, Aerosil 200, Aerosil 300 (trade name, manufactured by Nippon Aerosil Co., Ltd.); Nipsil VN-3- Wet silica such as LP (trade name, manufactured by Nippon Silica Kogyo Co., Ltd.); The average particle diameter is as described for the component (D).

Examples of non-reactive organosilicon compounds include CH ₃ Si (OCH ₃ ) ₃ , (CH ₃ ) ₃ SiOCH ₃ , PhSi (OCH ₃ ) ₃ , PhSiCH ₃ (OCH ₃ ) ₂ , {(CH ₃ ) ₃ Si} ₂ NH, CH ₃ CH ₂ Si (OCH ₃ ) _{3 and the} like (wherein “Ph” means a phenyl group).

  In addition, as a surface treatment method for the inorganic filler, the inorganic filler may be previously treated with the non-reactive organosilicon compound, and at the time of preparing the liquid epoxy resin composition of the present invention. The surface treatment may be performed by an integral blend method in which the non-reactive organosilicon compound is added and blended, but the former method is preferred from the viewpoint of suppressing the amount of the non-reactive organosilicon compound used.

  The amount of component (E) used is usually 1 to 5% by mass, preferably 2 to 3% by mass, based on the total amount of the liquid epoxy resin composition of the present invention. If the amount used is too small, it will be difficult to suppress the occurrence of bleeding of the liquid component, and conversely if too large, the thixotropy will be high, so that the fluidity of the epoxy resin composition will be substantially reduced, While it becomes difficult to obtain a liquid epoxy resin composition, there exists a possibility that the sealing performance by the side fill material of this invention may deteriorate.

[(F) Modified silicone resin]
The modified silicone resin of component (F) used in the liquid epoxy resin composition of the present invention is a component that is blended in order to relieve the stress of the resulting cured product and suppress the occurrence of cracks.

Examples of the component (F) include alkenyl group-containing resins selected from alkenyl group-containing epoxy resins and alkenyl group-containing phenol resins, and the following general composition formula (1):
H _a R _b SiO _{(4-ab) / 2} (1)
Wherein R is an unsubstituted or substituted monovalent hydrocarbon group other than an aliphatic unsaturated group, and a is a positive number of 0.005 to 0.1, preferably 0.01 to 0.05. , B is a positive number of 1.8 to 2.2, preferably 1.9 to 2.0, and the sum of a + b is 1.81 to 2.3, preferably 1.91 to 2.05. (It is a positive number.)
The number of silicon atoms in one molecule is 20 to 400, preferably 40 to 200, and 1 to 5 hydrogen atoms (SiH) bonded to silicon atoms in one molecule, preferably 2 to It is preferable to use an addition reaction product obtained by a hydrosilylation reaction with four, particularly preferably two, organohydrogenpolysiloxanes. The hydrosilylation reaction is a reaction in which the alkenyl group and the SiH are added and is well known to those skilled in the art. As usual, the hydrosilylation reaction may be performed using a platinum-based catalyst under known reaction conditions.

  As R which is a monovalent hydrocarbon group in the general composition formula (1), those having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms are preferable, for example, methyl group, ethyl group, propyl group, isopropyl group, Alkyl group such as butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group, decyl group; aryl group such as phenyl group, xylyl group, tolyl group; benzyl group, phenylethyl group, phenylpropyl group Aralkyl groups such as, and the like; and halogen substituted monovalent groups such as chloromethyl, bromoethyl, and trifluoropropyl groups in which some or all of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as chlorine, fluorine, and bromine A hydrocarbon group; and the like.

  As the modified silicone resin of component (F), a resin selected from a resin represented by the following general formula (2) and a resin represented by the following general formula (3) is particularly preferable.

(In the above formulas, R ¹ is a hydrogen atom, preferably an unsubstituted or substituted monovalent hydrocarbon group, alkoxy group or alkoxyalkyl group having 1 to 6 carbon atoms, and R ² is an aliphatic unsaturated group. R ³ is a hydrogen atom or a glycidyl group, R ⁴ is a hydrogen atom, a methyl group or a trifluoromethyl group, and R ⁵ is at the end of the formula Represents an unsubstituted or substituted divalent hydrocarbon group which may have an oxygen atom bonded to the Si atom, n is an integer of 0 or more, preferably 1 to 50, more preferably 1 to 10; Is an integer of 0 or more, preferably an integer of 1 to 50, more preferably an integer of 1 to 10, and q is an integer of 0 or more, preferably 1 to 200, more preferably 9 to 100.)

R ¹ in the above formula (2) is, for example, a hydrogen atom; an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group; an alkenyl group such as a vinyl group, an allyl group, or an isopropenyl group; a phenyl group; Preferred examples thereof include an alkoxy group such as a methoxy group and an ethoxyethyl group, and an alkoxyalkyl group.

Examples of R ² in the above formulas (2) and (3) include the same groups as those exemplified for R described in relation to the general composition formula (1). As the above-mentioned R ⁵ is, for _{example, -CH 2 CH 2 CH 2 -} , - O-CH 2 -CH (OH) -CH 2 -O-CH 2 CH 2 CH 2 -, - O-CH 2 CH ₂ CH ₂ — (wherein the oxygen atom at the end of the structure is bonded to a Si atom) or the like, an unsubstituted or substituted divalent carbonization such as an alkylene group which may contain a hydroxyl group or a hydroxyl group A hydrogen group is preferably exemplified. The modified silicone resin of component (F) can be used alone or in combination of two or more.

  The amount of the component (F) used may be an amount effective for stress relaxation of the cured product. For example, the organic component in the liquid epoxy resin composition of the present invention including the component (F) (that is, the above ( A), (B) component, (C) component, (F) component, and other organic components such as a curing accelerator) are generally 1 to 30% by mass, preferably 3 to 7% by mass. It is good to be about mass%.

[Other ingredients]
In addition to each said component, the liquid epoxy resin composition of this invention can mix | blend another component as needed. However, the obtained epoxy resin composition needs to be in a liquid state, and must not impair the effects of the present invention.

For example, silicone rubber, silicone oil, liquid polybutadiene rubber or the like may be blended in order to relieve the stress of the obtained cured product.
Further, a surface treatment agent, a silane coupling agent for improving adhesion, a pigment such as carbon black, a dye, an antioxidant, and other additives can be blended. Examples of the surface treatment agent include hexamethyldisilazane, tetraethoxysilane, and the like, and the surface of the inorganic filler component is hydrophobized to exert an effect on improving wettability with the resin component. Moreover, as said silane coupling agent, a well-known thing can be used, For example, KBM403 (brand name, the Shin-Etsu Chemical Co., Ltd. make) etc. are mentioned.

[Preparation of liquid epoxy resin composition]
The liquid epoxy resin composition of the present invention is agitated, dissolved, mixed, dispersed, etc. while the above components are simultaneously or sequentially introduced into the apparatus and a cooling treatment in the range of 15 to 25 ° C. is performed as necessary. It can prepare by performing operation of. The apparatus used for operations such as stirring, dissolution, mixing, and dispersion is not particularly limited. For example, a laika machine equipped with a stirring and heating device, a three-roll mill, a ball mill, a planetary mixer, or the like can be used. Further, a plurality of the devices may be combined as appropriate. However, when an acid anhydride is used as a curing agent, the adhesive property of the obtained side fill material tends to be reduced when the temperature is high, so the liquid of the present invention is used at a temperature of 10 to 25 ° C. It is preferable to prepare an epoxy resin composition.

  The liquid epoxy resin composition obtained in this manner is used from the viewpoint of workability and sealing properties when applied as a side fill material, and also from the side to the gap between the substrate and the semiconductor chip mounted on the substrate. In order to make it possible to control the intrusion of the fill material within an appropriate constant range, it is necessary that the viscosity at 25 ° C. is 100 Pa · s or more and less than 1000 Pa · s, particularly 150 to 600 Pa · s. Is preferred.

[Side fill material for flip chip mounting]
The liquid epoxy resin composition of the present invention is used as a side fill material for sealing a gap between a substrate and a semiconductor chip flip-chip mounted on the substrate at the periphery of the semiconductor chip. For the application method, sealing method, curing conditions, etc. of the side fill material of the present invention, known methods, conditions, etc. can be employed.

  For example, the sealing step includes storing the side fill material in a dispenser such as a syringe, and supplying a required amount of the side fill material from the dispenser to the sealing portion, and then performing a heat curing process. The conditions for the heat curing treatment are usually 150 to 200 ° C., particularly 170 to 190 ° C., usually 10 to 60 minutes.

[Semiconductor device]
As described above, the semiconductor device obtained by sealing with the flip-chip mounting side fill material of the present invention basically has the periphery of the semiconductor chip sealed, and in the gap between the substrate and the semiconductor chip. As a result of the required amount of the sealing material entering within an appropriate fixed range, the inside of the gap near the peripheral portion is filled with the side fill material. In the case of the semiconductor device according to the present invention, the contact area between the side fill material and the substrate is relatively large, which has the effect of suppressing the occurrence of cracks and the like. The degree of penetration mainly depends on material properties such as viscosity and fluidity of the side fill material.

  In the case of a semiconductor device sealed using the flip-chip mounting side fill material of the present invention, the width (L) of the gap between the substrate and the semiconductor chip mounted on the substrate, The ratio (M / L) with respect to the distance (M) from the end portion to the intruding tip portion of the cured product of the sidefill material that has entered the gap is more than 5 and not more than 25, preferably 6 to 24 The semiconductor device can be in the range of.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In Tables 1 to 3, “%” means mass%.

The materials used in the following examples and comparative examples are as follows.
(A) Liquid epoxy resin Bisphenol A type epoxy resin: RE310 (trade name, manufactured by Nippon Kayaku Co., Ltd.)
(B) Curing agent Acid anhydride: MH700 (trade name, manufactured by Shin Nippon Rika Co., Ltd.)
Curing accelerator Microencapsulated imidazole: HX-3741 (trade name, manufactured by Asahi Kasei Kogyo Co., Ltd.)
(C) Alkyl methacrylate copolymer F-351 (trade name, manufactured by Nippon Zeon Co., Ltd.)
(D) Inorganic filler As described below (in addition, the average particle diameter of the spherical silica used in each Example or Comparative Example and the content ratio of particles having a particle diameter of 45 μm or more are as described in the following table)
Examples 1-4; spherical silica (trade name: SE6200, manufactured by Admatechs)
Comparative Example 1: Spherical silica (prepared separately for the comparative example)
Comparative Example 2; spherical silica (trade name: SE2200, manufactured by Admatechs)
Comparative Example 3; spherical silica (trade name: SE-15, manufactured by Tokuyama Corporation)
Comparative Example 4 and Comparative Examples 6 to 9; spherical silica (trade name: SE6200, manufactured by Admatechs)
(E) Surface-treated inorganic filler Hexamethylsilazane: Fumed silica surface-treated with SE31 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.): Aerosil 130 (trade name, manufactured by Nippon Aerosil Co., Ltd., average particle size: 0.15 μm)
(F) Modified silicone resin

シランカップリング剤：ＫＢＭ４０３（商品名、信越化学工業社製）

Silane coupling agent: KBM403 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)

[Examples 1 to 4, Comparative Examples 1 to 9]
The said component was mix | blended with the composition and compounding quantity which are shown in following Table 1-3, and the epoxy resin composition was obtained by knead | mixing uniformly.

<Various performance evaluation>
-Viscosity The viscosity (Pa * s) in 25 degreeC of each obtained epoxy resin composition was measured using the Brookfield E-type viscosity meter. The measurement results are shown in Tables 1 to 3.
-Nozzle clogging Each epoxy resin composition obtained was stored in a syringe equipped with a nozzle with an inner diameter of 0.3 mm, extruded through the nozzle using a piston, and visually observed whether it could be extruded. did. If it was possible to extrude continuously, the nozzle was not clogged. When extrusion became difficult, the nozzle was clogged. The results are shown in Tables 1 to 3.

-Thermal expansion coefficient of hardened | cured material The prism sample was produced by hardening | curing each obtained epoxy resin composition on the conditions of 180 degreeC x 30 minutes in the type | mold of a shape of 5 mm x 5 mm x 15 mm.
Each sample is heated from 25 ° C. to 250 ° C. at a rate of temperature increase of 5 ° C./min using a TMA (thermomechanical analyzer), and the thermal expansion coefficient in the temperature range of 50 to 80 ° C. below Tg. It was measured. The measurement results are shown in Tables 1 to 3.

Thermal shock test A 10 mm square silicon chip was placed on a 30 mm × 30 mm square FRP substrate through a spacer made of microbeads having a particle size of 40 μm to produce a simulated semiconductor device. Each epoxy resin composition was dispensed on the periphery of the chip using a syringe. Subsequently, it hardened | cured on the conditions of 180 degreeC x 30 minutes, and the sealing body was obtained. After performing a thermal shock test in which a cooling cycle was applied to the sealed body at −40 to 150 ° C. and 100 cycles, whether or not a crack occurred in the sealed body was visually observed. Tables 1 to 3 show the presence or absence of occurrence of cracks.

Degree of penetration As shown in FIG. 1A, a spacer 2 made of microbeads having a particle diameter of 40 μm is placed on a glass plate 1 of 30 mm × 30 mm square, and a 10 mm square silicon chip 3 is placed thereon. It was mounted and a simulated semiconductor device was produced. Each of the epoxy resin compositions 7 was linearly dispensed from the nozzle 6 along the edge 4 on the side of the chip 3 using a syringe 5. Next, each epoxy resin composition was cured under conditions of 180 ° C. × 30 minutes.

Next, the penetration state of the cured product 8 was visually observed through the back surface of the glass plate 1, and the penetration degree was measured as follows.
Let L be the width of the gap 9 between the glass plate 1 formed by the spacer 2 and the chip 3. Let M be the longest distance from the end 4 of the chip 3 sealed with a cured product to the intrusion tip 10 of the cured product 8 that has entered the gap. M / L is defined as the penetration degree, and the measurement results are shown in Tables 1 to 3.

-Presence / absence of bleed In measuring the degree of penetration of the sealing material, whether the liquid component bleeds from the cured product through the rear surface of the glass plate 1 was visually observed. The results are shown in Tables 1 to 3.

（注）＊：液状ではない

(Note) *: Not liquid

（注）＊：液状ではない

(Note) *: Not liquid

(A) It is a figure which shows the outline of the apparatus used for the measuring method of the penetration degree of the side-fill material for flip-chip mounting, and the presence or absence of a bleed. (B) It is a figure which shows the outline of the state sealed by the said side fill material seen from the back surface of the glass plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass plate 2 Spacer 3 Silicon | silicone chip | tip 4 End part 5 Syringe 6 Nozzle 7 Epoxy resin composition 8 Hardened | cured material 9 Gap | interval 10 Hardened | cured material penetration | invasion front-end | tip L Gap width M Distance from the end |

Claims (4)

(A) Liquid epoxy resin,
(B) Curing agent : The amount of the functional group contained in the component (B) with respect to 1 mol of the epoxy group in the component (A) (however, in the case of a polyvalent functional group, there are plural monovalent groups Converted to 0.8) to 1.2 mol ,
(C) alkyl methacrylate copolymer : 1 to 5% by mass relative to the total amount of the liquid epoxy resin composition ,
(D) Inorganic filler having a content of particles having a particle size of 45 μm or more of 1% by mass or less and an average particle size of 0.5 μm or more and less than 5 μm : 30 to 60 based on the total amount of the liquid epoxy resin composition Mass% ,
(E) An inorganic filler having an average particle diameter of 0.01 to 0.15 μm, which has been surface-treated with a non-reactive organosilicon compound : 1 to 5% by mass based on the total amount of the liquid epoxy resin composition , and (F) Modified silicone resin : 1 to 30% by mass relative to the total mass of organic components in the present liquid epoxy resin composition
A flip-chip mounting side fill for a semiconductor device comprising a substrate and a semiconductor chip mounted on the substrate, the composition comprising a liquid epoxy resin composition having a viscosity of 100 Pa · s to less than 1000 Pa · s at 25 ° C. Wood. The component (F) is an alkenyl group-containing resin selected from an alkenyl group-containing epoxy resin and an alkenyl group-containing phenol resin, and the following general composition formula (1):
H _a R _b SiO _{(4-ab) / 2} (1)
Wherein R is an unsubstituted or substituted monovalent hydrocarbon group other than an aliphatic unsaturated group, a is a positive number from 0.005 to 0.1, and b is from 1.8 to 2.2. And the sum of a + b is a positive number from 1.81 to 2.3.)
2. For flip chip mounting according to claim 1, which is an addition reaction product obtained by a hydrosilylation reaction with an organohydrogenpolysiloxane having 20 to 400 silicon atoms in one molecule. Sidefill material. The flip chip mounting side according to claim 1 or 2, wherein the component (F) is a resin selected from a resin represented by the following general formula (2) and a resin represented by the following general formula (3). Fill material.

(In the above formulas, R ¹ is a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group, an alkoxy group or an alkoxyalkyl group, and R ² is an unsubstituted or substituted monovalent carbon other than an aliphatic unsaturated group. A hydrogen group, R ³ is a hydrogen atom or a glycidyl group, R ⁴ is a hydrogen atom, a methyl group or a trifluoromethyl group, and R ⁵ has an oxygen atom bonded to the Si atom in the formula at the terminal. And represents an unsubstituted or substituted divalent hydrocarbon group, and n, p and q are each an integer of 0 or more.)   A semiconductor device sealed with a flip-chip mounting side-fill material according to any one of claims 1 to 3, wherein a width of a gap (L between a substrate and a semiconductor chip mounted on the substrate) ) And the distance (M) from the end of the semiconductor chip to the intrusion tip of the cured product of the side fill material that has entered and entered the gap exceeds 5 (M / L) The semiconductor device within a range of 25 or less.

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