JP5278385B2 - Mounting sealing material and semiconductor device sealed using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing agent for a semiconductor device, which is excellent in storage stability and low-temperature/speed curableness, in which a cured material is useful for an underfill material rigid at room temperature and having repair performance and rework performance, and which improves the drop resistance of a compact electronic apparatus. <P>SOLUTION: The sealing material for mounting the semiconductor device contains: (A) 100 pts.mass of a liquid epoxy resin having two or more epoxy groups in one molecular; (B) a liquid phenol resin containing an alkenyl group; (C) 1.5 to 50 pts.mass of a micro-capsulated curing accelerator as an effective component; (D) a reactive diluent composed of an epoxy component having one epoxy group in one molecular; and (E) 0 or more pts.mass of an inorganic filler. The sealing material is composed of an insoluble composition, wherein a mol ratio of all epoxy groups in the composition to a phenol hydroxy group in the (B) component is 1.3 to 3.0. The sealing material is used for mounting the semiconductor device including: a base board, and an element mounted on the base board. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a sealing material for mounting a semiconductor device, and in particular, for mounting useful as an underfill material for sealing between a semiconductor element and a wiring board or between a carrier substrate holding a semiconductor element and a wiring board. It relates to a sealing material. Specifically, it is a packaging that consists of a solvent-free one-component epoxy resin composition that cures sufficiently at a low temperature in a short time, has excellent storage stability, has excellent mechanical strength at low temperatures, and can be easily removed at high temperatures. It is related with the sealing material.

  With the downsizing, weight reduction, and high performance of electrical equipment, surface mounting, that is, bare chip mounting, has been adopted in recent years as a semiconductor mounting method instead of the conventional lead wire type. In general, a solder bump bonding type semiconductor device such as BGA or CSP is inferior in reliability as compared with a lead connection type semiconductor device having a stress relaxation function by a lead because an impact is directly transmitted to solder. Therefore, various reinforcements are performed in order to improve reliability. (See Patent Documents 1 to 3)

  Also, when mounting, the sealing method with the sealing material is to seal the gap between the substrate derived from the bump height of the LSI chip and the element such as the semiconductor chip in the gap. There is an underfill method to fill

  Usually, because the substrate used is expensive, if a mounted device malfunctions, a process for repairing and reworking the device is required, but epoxy resins are thermally and chemically stable. High mechanical strength. These properties are ideal as reinforcing materials, but are difficult to remove once cured. Therefore, when used as an underfill material, repair and rework are difficult. As a result, the substrate has to be discarded and suffers an economic loss. On the other hand, in recent years, in the case of small electronic devices such as mobile phones and mobile personal computers, high drop resistance is required at room temperature, and therefore, materials having higher mechanical strength and better elongation are required. .

  When BGA and CSP and electronic parts such as quartz crystal units and parts with poor heat resistance such as plastic parts are mounted together, curing at low temperature is required, and short time curing is required from the viewpoint of workability. It has been. The present inventors previously provided a semiconductor product having good thermal shock resistance, repairable and reworkable, and a sealing material for mounting that has good gap penetration, as a liquid epoxy resin, a phenolic curing agent, A composition containing propylene glycol monomethyl ether and an inorganic filler was proposed (see Patent Document 4). However, the material does not reach a level that sufficiently satisfies the storage stability. In general, a large amount of a curing agent or a curing accelerator is generally added to develop a low-temperature rapid curability, but this will impair the stability of the viscosity when injected as an underfill material. So it was never preferable.

  On the other hand, the underfill material used in the application needs to have excellent mechanical strength at room temperature, but particularly high toughness is required in recent years when more mechanical reliability is required. In the case of an epoxy resin-based encapsulant mainly composed of an epoxy resin and a phenol resin, the toughness of the cured product can be increased by making the molar ratio of epoxy group / phenolic hydroxyl group larger than the equivalent ratio. It was possible.

  Further, by using a silicone-modified liquid epoxy resin as an epoxy resin, the impact resistance of the cured product is improved, and a microcapsule type imidazole derivative epoxy compound is added in an amount of 0.6 to 100 in 100 parts by mass of the epoxy resin in order to compensate for low reactivity. A semiconductor encapsulant containing part by mass is known (see Patent Document 5). However, when a large amount of the curing catalyst is blended in this way, fast curability can be obtained, but the storage stability of the sealant is deteriorated, and sufficient reworkability cannot be obtained.

The sealing material described in Patent Document 4 described above was able to improve repairability and reworkability by including propylene glycol monomethyl ether acetate in the liquid epoxy resin composition. There was a problem that the shell material of the hardening accelerator that was microencapsulated was dissolved, and the storage stability of the sealant was impaired due to the outflow of the hardening accelerator in the microcapsule.

JP 9-260534 A Japanese Patent Laid-Open No. 10-321666 JP 2001-77246 A JP 2008-177521 A JP 2002-293880 A

  Therefore, the present invention has sufficient storage stability and good low-temperature curability and fast curability, the cured product is tough at room temperature, and has repairability and reworkability, particularly useful as an underfill material. It is an object of the present invention to provide a sealant for solventless semiconductor devices.

As a result of intensive studies to achieve the above object, the present inventor has achieved the object as follows:
(A) 100 parts by mass of a liquid epoxy resin having two or more epoxy groups in one molecule,
(B) an alkenyl group-containing liquid phenol resin,
(C) Microencapsulated curing accelerator 1.5-50 parts by mass as an active ingredient,
(D) Reactive diluent consisting of an epoxy compound having one epoxy group in one molecule, and (E) Inorganic filler 0 part by mass or more and less than 100 parts by mass,
The molar ratio of [total epoxy groups in this composition / phenolic hydroxyl groups in component (B)] is 1.3 to 3.0,
Provided is a sealing material for mounting a semiconductor device having a substrate and an element mounted on the substrate, which is made of a solvent-free composition.

  Secondly, the present invention provides a semiconductor device having a semiconductor element and a cured product obtained by curing the sealing material and sealing the semiconductor element.

  In particular, the present invention provides a semiconductor device having a substrate, a semiconductor chip mounted on the substrate, and a cured product in which the sealing material is filled and cured in a gap between the substrate and the semiconductor chip. provide.

  In the sealing material comprising the one-pack type epoxy resin composition of the present invention, the molar ratio of epoxy group / phenolic hydroxyl group is larger than the equivalent ratio, and the catalyst is microencapsulated using an excessive amount of catalyst. Therefore, it is excellent in storage stability at room temperature. In addition, it exhibits good fast curability at a low temperature above a certain temperature, has excellent mechanical strength at room temperature, and has repairability and reworkability. Since this sealing material is a solvent-free type and does not contain an organic solvent, the drawbacks of the conventional sealing materials using an organic solvent could be overcome. In particular, since the elongation at room temperature is good and the toughness is high, the electronic device can be provided with good drop resistance.

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 mounting sealing 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.

  As the liquid epoxy resin of component (A), an epoxy-modified silicone resin can be further used. The epoxy-modified silicone resin is preferred for imparting drop impact resistance to the cured product of the composition of the present invention. The epoxy-modified silicone resin has an effect of relaxing the stress of the obtained cured product and suppressing the occurrence of cracks.

Examples of the epoxy-modified silicone resin include an alkenyl group-containing epoxy resin and the following average 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 0.10, preferably 0.01 to 0.05. , B is a positive number of 1.80 to 2.20, preferably 1.90 to 2.00, and the sum of a + b is 1.81 to 2.30, preferably 1.91 to 2.05. (It is a positive number.)
And the number of silicon atoms in one molecule is 20 to 400, preferably 40 to 200, and preferably 1 to 5 hydrogen atoms (SiH groups) bonded to silicon atoms in one molecule. It is preferable to use an addition reaction product obtained by a hydrosilylation reaction with an organohydrogenpolysiloxane having preferably 2 to 4, particularly preferably 2. The hydrosilylation reaction is a reaction in which the alkenyl group and the SiH group are added and is well known to those skilled in the art. As usual, the reaction can be carried out using a platinum-based catalyst under known reaction conditions. Good.

  As R which is an unsubstituted or substituted monovalent hydrocarbon group other than the aliphatic unsaturated group in the average composition formula (1), those having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms are preferable. Alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, cyclohexyl, octyl and decyl; aryl such as phenyl, xylyl and tolyl Groups: Aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and halogen-substituted monovalent carbons in which some or all of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as chlorine, fluorine, and bromine Examples thereof include a hydrogen group such as a chloromethyl group, a bromoethyl group, and a trifluoropropyl group.

  The epoxy-modified silicone resin is particularly preferably a resin represented by the following general formula (2) or a resin represented by the following general formula (3).

(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 0 or more, preferably 18 to 398, more preferably an integer of 48 to 148, p 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 with respect to the above average composition formula (1). Further, the above-mentioned ^{R 5,} 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 Non-substituted or substituted divalent hydrocarbon such as an oxygen atom represented by CH ₂ — (wherein the oxygen atom at the end of the structure is bonded to a Si atom) or an alkylene group which may contain a hydroxyl group The group is preferably exemplified.

  Epoxy-modified silicone resins can be used singly or in combination of two or more.

  The amount of the epoxy-modified silicone resin 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 (that is, the component (A) above) , (B) component, (C) component, and curing accelerator) is usually 1 to 50% by mass, preferably about 5 to 40% by mass. If the amount of the modified silicone resin component is too small, the impact resistance against dropping may deteriorate, and if it is too large, the viscosity may increase and workability may deteriorate. Moreover, it is preferable that this epoxy-modified silicone resin is 5-40 mass% in (A) component, and it is more preferable that it is 15-30 mass%.

  The total chlorine content contained in the component (A) liquid epoxy resin is preferably 1500 ppm or less, particularly 1000 ppm or less as chlorine atoms. The amount of chlorine ions extracted under conditions of 100 ° C. × 20 hours in water containing 50% by mass of the liquid epoxy resin as the component (A) is preferably 10 ppm or less. If the total chlorine content and the amount of extracted chlorine ions are within such ranges, the resulting cured product has good moisture resistance and does not impair the reliability of the semiconductor device.

[(B) Liquid phenol resin containing alkenyl group]
The alkenyl group-containing liquid phenol resin as the component (B) used in the liquid epoxy resin composition of the present invention acts as a curing agent for the liquid epoxy resin as the component (A).

As a specific example of the liquid phenol resin, a phenol resin represented by the following formula (4) is particularly preferable.

(Wherein R ₁ is an alkylene group, preferably a linear alkylene group having 1 to 15 carbon atoms or a branched alkylene group, R ₂ is an alkenyl group having 2 to 6 carbon atoms, and n is 0. It is an integer of ˜5, preferably an integer of 1 to 3.)

The amount of component (B) is such that the molar ratio of [total epoxy groups in the composition / phenolic hydroxyl group in component (B)] is 1.3 to 3.0, preferably 1.5. ~ 2.5. If the molar ratio is lower than 1.3, a cured product having insufficient physical properties such as mechanical properties after curing can be obtained. If the molar ratio exceeds 3.0, the curing accelerator functions as a curing agent and gradually cures. Decrease in mechanical strength of objects.

Although this composition may contain other epoxy compounds other than (A) component and (D) component, the quantity of these other epoxy compounds is 10 mol% or less in conversion of an epoxy group in all the epoxy compounds. It is desirable. When the epoxy compound contained in this composition is only the (A) component and the (D) component, only those contained in the (A) component and the (D) component are considered as the epoxy group.

Conventionally, in an epoxy resin composition, intentionally shifting the molar ratio of epoxy group / phenolic hydroxyl group from the equivalent ratio has not been performed because the strength of the resulting cured product becomes brittle. In the present invention, the curing accelerator is microencapsulated and used in a large amount, and by setting the molar ratio higher than the equivalent ratio, it is possible to improve the strength of the cured product and the glass transition temperature. It was.

  5-80 mass parts is preferable with respect to 100 mass parts of liquid epoxy resins of the said (A) component, and, as for the phenol resin of this (B) component, 40-70 mass parts is more preferable.

[(C) Microencapsulated curing accelerator]
In the liquid epoxy resin composition of the present invention, a curing accelerator is used together with the curing agent of the component (B). This curing accelerator enables low temperature rapid curing and is added in a large amount. In addition, in order to maintain storage stability, it is used by microencapsulation. In addition, as a curing accelerator (catalyst) used as an active ingredient for the core material of the microcapsule, a reaction temperature (that is, catalytic action) is exhibited so as to exhibit storage stability and rapid curability at a low temperature above a certain temperature. Is preferably 60 ° C. or higher, more preferably in the range of 70 to 150 ° C., and still more preferably in the range of 80 to 120 ° C. Examples of the curing accelerator include imidazole compounds, tertiary amine compounds, and organic phosphorus compounds.

  Examples of the imidazole compound include 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2,4-dimethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 1,2-diethyl. Imidazole, 2-phenyl-4-methylimidazole, 2,4,5-triphenylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2- Methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-allyl-4,5-diphenylimidazole, 2-phenyl-4 -Methyl-5 Hydroxymethyl 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 its phenol salts, cycloamidine compounds such as octylates and oleates, and salts thereof with organic acids; cycloamidine compounds such as compounds represented by the following structural formula; Examples thereof include salts or complex salts with quaternary boron compounds.

  Examples of the organophosphorus compounds include tributylphosphine, triphenylphosphine, tri (methylphenyl) phosphine, tri (nonylphenyl) phosphine, tri (methoxyphenyl) phosphine, diphenyltolylphosphine, triphenylphosphine / triphenyl. Examples include triorganophosphine compounds such as borane; quaternary phosphonium salts such as tetraphenylphosphonium and tetraphenylborate.

  These curing accelerators can be used singly or in combination of two or more.

  The shell material for microencapsulating the curing accelerator needs to have a melting point of 60 to 90 ° C., preferably 65 to 85 ° C., more preferably 70 to 85, from the viewpoint of maintaining storage stability and ensuring fast curability. ° C. The material of the shell material is not particularly limited as long as it has such a melting point, and all known materials can be used, for example, (meth) acrylic monomers such as acrylic acid esters and itaconic acid esters. An alkyl ester having 1 to 8 carbon atoms such as crotonic acid ester; an alkyl group of this alkyl ester having a substituent such as an allyl group; styrene, α-methylstyrene, acrylonitrile, methacrylonitrile, vinyl acetate, etc. Monofunctional monomer; and selected from polyfunctional monomers such as ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, divinylbenzene, bisphenol A di (meth) acrylate, and methylenebis (meth) acrylamide By (co) polymerizing one or more monomers The polymer can be mentioned. Among these polymers, a polymer of (meth) acrylate monomers is preferable.

  The (C) component microencapsulated curing accelerator is obtained by confining a curing accelerator in such a shell material.

  The amount of the microencapsulated curing accelerator used as the component (C) is 1.5 to 50 parts by mass, preferably 10 to 45 parts by mass, as an active ingredient, per 100 parts by mass of the component (A). Preferably it is 15-40 mass parts. If the amount is too small, low temperature rapid curability cannot be expected.

  When preparing the composition of the present invention by blending the microencapsulated curing accelerator of component (C) with other components, the microencapsulated curing accelerator of component (C) is preliminarily liquid as component (A). It is preferable to disperse it in at least a part of the epoxy resin. Such preliminary dispersion not only improves the workability of the blending because the component (C) can be handled as a liquid material, but also contributes to the improvement of the low-temperature fast curability and storage stability of the resulting composition. Preliminary dispersion is presumed to be due to the epoxy resin-rich state of the component (A) around the catalyst that is the core material of the microcapsules in the resulting composition. In this preliminary dispersion, the microencapsulated curing accelerator of the component (C) may be dispersed in the total amount of the liquid epoxy resin of the component (A) to be used, or may be dispersed in a part of the component (A). Also good. The ratio of the (A) component and the (C) component when predispersed is 60 to 95 for the liquid epoxy resin of the (A) component with respect to 5 to 40 parts by mass of the microencapsulated curing accelerator of the (C) component. Part by mass is preferred.

[(D) Epoxy compound-based reactive diluent]
(D) The reactive diluent of a component consists of an epoxy compound which has one epoxy group in 1 molecule. By introducing a monofunctional epoxy compound into the resin skeleton, a sparse part is generated in the chemical structure at a temperature equal to or higher than the glass transition temperature, which has an effect of being easily removed during rework. The reactive diluent is not particularly limited as long as it has one epoxy group in one molecule. For example, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, para-tertiary butyl phenyl glycidyl. Examples include ether and dibromophenyl glycidyl ether. These compounds may be used alone or in combination of two or more. Among these, a compound having a phenyl group is preferable as a component imparting strength.

  (D) It is preferable that 5-40 mass parts is mix | blended with respect to 100 mass parts of (A) component, More preferably, it is 10-35 mass parts, More preferably, it is 10-30 mass parts.

[(E) inorganic filler]
(E) The inorganic filler of component is in the range of 0 to less than 100 parts by weight, preferably 0 to 65 parts by weight, more preferably 0 to 35 parts by weight per 100 parts by weight of component (A). Can be blended. An inorganic filler is not essential, but it can improve mechanical strength such as fracture toughness, dimensional stability at high temperature, and moisture resistance by addition. However, when there are too many compounding quantities, the elongation and toughness of hardened | cured material will fall, and the drop resistance of an electronic device will fall.

Examples of inorganic fillers include silicates such as talc, calcined clay, unfired clay, mica, and glass, titanium oxide, alumina, fused silica (fused spherical silica, fused crushed silica), synthetic silica, and crystalline silica. Oxides such as silica powder, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, sulfates such as barium sulfate, calcium sulfate and calcium sulfite Alternatively, borates such as sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, and sodium borate, and nitrides such as aluminum nitride, boron nitride, and silicon nitride can be used. These inorganic fillers may be used alone or in combination. Among these, fused silica, crystalline silica, and synthetic silica powder are preferable because the heat resistance, moisture resistance, strength, and the like of the resin composition can be improved. The shape of the inorganic filler is not particularly limited, but the shape is preferably spherical from the viewpoint of viscosity and flow characteristics.
Moreover, when using the said inorganic filler for a semiconductor device, the average particle diameter is although it does not specifically limit, 0.1-30 micrometers is preferable and 0.2-8 micrometers is especially preferable. When the average particle diameter exceeds the lower limit value, the viscosity of the resin composition is moderately lowered and the effect of improving the fluidity is increased. When the average particle diameter is less than the upper limit value, the resin composition flows into the semiconductor device. The effect of suppressing partial unfilling or filling failure due to filler clogging is enhanced.

[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.

・ Other optional ingredients:
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. These also contribute to the improvement of the impact resistance of the cured product against dropping. Further, a surface treating agent, a silane coupling agent for improving adhesiveness, 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. The surface treatment agent hydrophobizes the surface of the inorganic filler component and exhibits an effect of 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. When using the reactive diluent for viscosity reduction other than (D) component, it is preferable that the compounding quantity is 10 mass% or less of the total of the quantity of (D) component.

[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.

  When the liquid epoxy resin composition thus obtained is applied as an underfill material, the viscosity at 25 ° C. must be 1 Pa · s or more and less than 20 Pa · s so as to have good gap penetration. In particular, when it is necessary to enter at room temperature, it is preferably 1 to 4 Pa · s. In the present specification, the viscosity is a value measured with an E-type viscometer manufactured by Brookfield.

[Underfill material for mounting]
The liquid epoxy resin composition of the present invention is suitable as an underfill material for sealing a gap between a substrate and a semiconductor chip mounted on the substrate over the entire surface under the semiconductor chip. Known methods, conditions, and the like can be employed for the underfill material application method, sealing method, curing conditions, and the like.

  For example, as a sealing process, a device dried in advance is placed on a hot plate heated to 25 to 50 ° C., and a coating device such as a dispenser is used, and 2 adjacent to each other at right angles among the four sides of the chip. The composition of the amount of 30-50 mg / time is dripped 2-4 times to the edge | side, and it apply | coats. The conditions for the heat curing treatment of the composition applied to the device are usually 100 to 150 ° C. and 5 to 40 minutes.

  As described above, the semiconductor device obtained by sealing with the mounting underfill material of the present invention basically has the entire surface under the semiconductor chip sealed. Since the underfill material for mounting according to the present invention has a good gap penetration property, it can be sealed without voids.

  Since the mounting sealing material (underfill material) of the present invention has repairability and reworkability, when removing a device with poor reliability, the device is heated to 200 to 260 ° C., which is the solder melting point, with a spot heater. Thus, after the removal, the solder residue and the sealing material residue are removed by the solder absorption line, and the semiconductor device can be repaired and reworked easily by a process of cleaning with a solvent such as isopropyl alcohol.

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 addition, the "part" in Tables 1-3 means a mass part.

The materials used in the following examples and comparative examples are as follows. The viscosity is a viscosity measured using a Brookfield E-type viscometer at room temperature (25 ° C.) unless otherwise specified.
(A) Liquid epoxy resin / bisphenol A type epoxy resin: RE-310S (trade name, manufactured by Nippon Kayaku Co., Ltd.) Epoxy equivalent: 184
-Bisphenol F type epoxy resin: YDF8170 (trade name, manufactured by Tohto Kasei Co., Ltd.) Epoxy equivalent: 160
Trifunctional epoxy resin (having three epoxy groups in one molecule): EP-630LSD (trade name, manufactured by Japan Epoxy Resin Co., Ltd.) Epoxy equivalent: 101
・ The following epoxy-modified silicone resin

Epoxy equivalent: 220
Si content: 14% by mass

(B) Alkenyl group-containing phenol resin (curing agent)
Allyl group-containing phenol resin: MEH-8000H (trade name, manufactured by Meiwa Kasei Co., Ltd.)
Viscosity: 1500-3500 mPa · s, hydroxyl group equivalent: 141 g / eq

(C) Microencapsulated curing accelerator / microencapsulated imidazole catalyst:
HX-3088 (trade name, manufactured by Asahi Kasei Co., Ltd.) Epoxy equivalent: 276, average particle diameter of 2 μm of curing accelerator as core material, dispersed in epoxy resin corresponding to component (A). Epoxy resin / curing accelerator (mass ratio) = 60-70 / 30-40

(D) Reactive diluent, para-tertiary butylphenol glycidyl ether (trade name: EX-146, manufactured by Nagase ChemteX Corporation) Epoxy equivalent: 226

(E) Other components / solvent Propylene glycol monomethyl ether acetate (hereinafter abbreviated as PGMEA), PMA (trade name, manufactured by Kyowa Hakko Chemical Co., Ltd.)
・ Silane coupling agent KBM403 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
・ Pigment Adeka Black (trade name, Adeka)
・ Inorganic filler Spherical silica (average particle size 2μm)
・ Liquid polyamine resin Kayahard A-A (PT) (trade name, manufactured by Nippon Kayaku)
Curing accelerator: TTP (triphenylphosphine)

[Example 1; Comparative Examples 1 and 2]
The said component was mix | blended with the composition and compounding quantity which are shown in following Table 1, and the epoxy resin composition was obtained by knead | mixing uniformly. Various performance evaluations shown below were performed for these compositions. The evaluation results are shown in Table 1.

<Various performance evaluation>
-Adhesive strength The epoxy resin composition was applied to an organic substrate (solder resist), a 2 mm x 2 mm Si chip was placed, and heated and dried in an oven heated to 150 ° C for 2 hours to be sufficiently cured. The cured film surface of the composition of the substrate after the curing treatment was allowed to stand on a hot plate at 260 ° C. for 40 seconds, allowed to cool to room temperature, and then the adhesive strength was measured.

Storage stability An appropriate amount of an epoxy resin composition is packed in a syringe, and an initial viscosity at 25 ° C. and a viscosity after being allowed to stand at 25 ° C. for 24 hours are determined using a Brookfield E-type viscometer. Asked.

(Evaluation) By adding a solvent from Table 1, the adhesive strength at 260 ° C. was reduced and the reworkability was improved, but the storage stability was inferior. By adding a reactive diluent, reworkability was improved over the solvent even when the same amount was added, and a resin having excellent storage stability could be prepared.

[Example 2]
The said component was mix | blended with the composition and compounding quantity which are shown in following Table 2, and the epoxy resin composition was obtained by knead | mixing uniformly. Each of these compositions was subjected to various performance evaluations shown below. The evaluation results are shown in Table 2.

<Various performance evaluation>
-Reactivity The epoxy resin composition was weighed in a 10 mg aluminum pan and left in an oven heated to 100 ° C for 40 minutes or in an oven heated to 115 ° C for 10 minutes. Then, the reaction heat was calculated | required using DSC821e Module (made by METLER TOLEDO), the ratio with the reaction rate before a heating was calculated, and the hardening reaction rate was calculated | required.

Storage stability An appropriate amount of an epoxy resin composition is packed in a syringe, and an initial viscosity at 25 ° C. and a viscosity after being allowed to stand at 25 ° C. for 24 hours are determined using a Brookfield E-type viscometer. Asked.

[Examples 3 and 4; Comparative Example 3]
The said component was mix | blended with the composition and compounding quantity which are shown in following Table 3, and the epoxy resin composition was obtained by knead | mixing uniformly. Each of these compositions was subjected to various performance evaluations shown below. The evaluation results are shown in Table 3.

<Various performance evaluation>
-Glass transition temperature The epoxy resin composition was weighed on a 10 mg aluminum pan, heated in an oven heated to 150 ° C for 2 hours, dried, and sufficiently cured. The glass transition temperature of the obtained cured product was measured using DSC821e Module (manufactured by METLER TOLEDO), and the glass transition temperature was determined from the tangential contact of the endothermic curve.

-Mechanical strength The epoxy resin composition was put in a mold and heated and dried in an oven heated to 150 ° C. for 2 hours to be sufficiently cured. The mechanical strength after curing was measured using AGS-5kNG (manufactured by Shimadzu Test Service Co., Ltd.).

(Evaluation) From the results in Table 3, it can be seen that by increasing the molar ratio of epoxy group / phenolic hydroxyl group, the glass transition temperature is increased and the mechanical strength, in particular, the displacement at break representing the elongation is improved.

  The sealing material for mounting a semiconductor device of the present invention is useful for manufacturing a semiconductor device.

Claims (9)

(A) 100 parts by mass of a liquid epoxy resin having two or more epoxy groups in one molecule,
(B) an alkenyl group-containing liquid phenol resin,
(C) Microencapsulated curing accelerator 1.5-50 parts by mass as an active ingredient,
(D) off E alkenyl glycidyl ether is selected from para-tertiary butyl phenyl glycidyl ether and dibromophenyl glycidyl ether, one or composed of two or more reactive diluents epoxy compound having one epoxy group per molecule ( A) It contains 19 to 43 parts by mass with respect to 100 parts by mass of the component, and (E) an inorganic filler of 0 part by mass or more and less than 100 parts by mass,
The molar ratio of [total epoxy groups in the composition / phenolic hydroxyl groups in the component (B)] is 1.3 to 3.0.
A sealing material for mounting a semiconductor device, comprising a substrate and an element mounted on the substrate, comprising a solvent-free composition. The sealing material for mounting a semiconductor device according to claim 1, wherein the component (A) includes a liquid epoxy-modified silicone resin having two or more epoxy groups in one molecule. The packaging material for mounting a semiconductor device according to claim 1 or 2, wherein the alkenyl group-containing phenol resin of component (B) is represented by the general formula (4).
(Wherein R ₁ is an alkylene group, R ₂ is an alkenyl group having 2 to 6 carbon atoms, and n is an integer of 0 to 5) The mounting according to any one of claims 1 to 3, wherein the component (C) includes a core material made of a catalyst having a reaction temperature of 60 ° C or higher and a shell material having a melting point of 60 to 90 ° C. Sealing material. The mounting sealing material according to any one of claims 1 to 4, wherein the component (C) is contained in an amount of 15 to 40 parts by mass as an active ingredient per 100 parts by mass of the component (A). The (C) component microencapsulated curing accelerator is preliminarily dispersed in at least a part of the epoxy resin of the (A) component and then blended with other components according to any one of claims 1 to 5. Such a sealing material for mounting. Mounting sealing material according to any one of claims 1 to 6 used as an underfill material that seals a gap between the substrate and the base semiconductor chip mounted on board. A semiconductor element obtained by curing the mounting sealing material according to any one of claims 1 to 7, a semiconductor device having a cured product that seals the semiconductor element. Curing in which the mounting sealing material according to any one of claims 1 to 7 is filled and cured in a substrate, a semiconductor chip mounted on the substrate, and a gap between the substrate and the semiconductor chip Semiconductor device.