JP2010143949A - Underfill material and semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hardened material which is suitable for semiconductor sealing, has a very good adhesion to the element surface of a silicon chip and has a high moisture resistance, and particularly a high temperature thermal shock having a reflow temperature of 260 ° C. or higher. The present invention relates to a liquid epoxy resin composition that can be an excellent sealing material, and a semiconductor device sealed with this composition.
SOLUTION: A liquid epoxy resin, (B) an aromatic amine curing agent, and (C) a liquid resin composition for underfill which must contain an inorganic filler, and curing the composition. An underfill material characterized in that a reaction start temperature during the reaction is adjusted to 160 ° C. or lower.
[Selection figure] None

Description

  The present invention is suitable for semiconductor sealing, has very good adhesion to the element surface (especially photosensitive polyimide, nitride film, oxide film) of the silicon chip, and gives a cured product with high moisture resistance. The present invention relates to a liquid epoxy resin composition that can be an excellent sealing material against a high temperature thermal shock at a reflow temperature of 260 ° C. or higher, and a semiconductor device sealed with this composition.

  As electrical devices become smaller, lighter, and more functional, devices such as CPUs and GPUs are becoming popular because of the pin insertion type to flip chip mounting. Flip chip type mounting is one of the most effective mounting methods for minimizing and increasing the speed of a semiconductor package because a solder bump electrode is provided on the surface of a semiconductor chip and directly connected to electrodes called substrate pads. When the flip chip type mounting is adopted, the gap between the semiconductor chip and the substrate formed by the protruding electrode is prevented in order to prevent the protruding electrode from being destroyed due to the stress generated when the thermal expansion coefficients of the semiconductor chip and the substrate or the solder are different from each other. A resin called an underfill agent is injected and sealed.

  In flip chip mounting using solder, in order to obtain a good connection between the solder bump electrode and the substrate, a method is used in which the flux is processed on the substrate and / or the bump electrode and then the solder is melted and connected in a reflow furnace or the like. The flux is used to remove the metal oxide layer, which is a high melting point layer on the solder surface, and to prevent reoxidation. However, in the sealing of the underfill agent performed after the solder connection, the flux is an underfill. In order to inhibit the injection of the agent, it is generally washed and removed using pure water or a solvent. However, due to the recent miniaturization of electronic circuits, the pitch between electrodes and the height of protruding electrodes have been narrowed, so that cleaning cannot be performed in detail and it is difficult to completely remove flux, and residual flux remains. There are many more.

  The underfill agent is injected at a high temperature of 100 ° C. or higher, but the flux also has a low viscosity at such a temperature. The flux whose viscosity has been reduced in the gap generally floats due to its low specific gravity relative to the underfill material, and may form a layer as if the underfill filler had settled. Such a sedimentation layer is often formed around the projection electrode, but it appears that there are voids around the projection electrode in SAT inspection (ultrasonic tomography), which is typically used for flip chip inspection. When it is difficult to judge the quality of the product, or when the residue is re-melted, the flux activity is exhibited, and the oxide layer formed on the solder bump electrode is removed and released as a gas such as water, resulting in a void. I have a problem.

To solve such a problem, a method has been proposed in which the underfill is injected as it is without cleaning by purifying the flux with high purity and low residue. (Patent Document 1)
In addition, a method has been proposed in which a flux cleaning agent or the like is added to the underfill material and the flux is mixed with the underfill material and removed. (Patent Document 2)

However, in the method of Patent Document 1, a small amount of flux remains, but the above problem remains. In addition, the flux often forms a salt with the solder component, but the salt often greatly reduces the adhesiveness of the UF, which may reduce the reliability of the device.
Moreover, since the flux cleaning agent used in Patent Document 2 also inhibits the adhesion of the underfill agent, there is a concern that the reliability of the device may be lowered.

In addition, as a related prior art document of the said description matter, the following patent documents 1-patent document 3 are mentioned.
JP-A-8-288638 JP 2006-160852 A JP 2007-231146 A

  The present invention has been made in view of the above-described matters, and an object of the present invention is to prevent the generation of voids and improve the reliability without causing flux residue to float.

  As a result of intensive studies to achieve the above object, the present inventor has as a result required to contain (A) a liquid epoxy resin, (B) an aromatic amine-based curing agent, and (C) an inorganic filler. It is a resin composition, and it has been found that it is effective to adjust the reaction start temperature when the composition is subjected to a curing reaction to 160 ° C. or less, and has led to the present invention.

  By using the underfill material of the present invention, it is possible to provide a semiconductor device in which there is no flux residue floating layer and no flux-induced voids are generated.

  Hereinafter, the liquid resin composition (underfill material) and the semiconductor device of the present invention will be described in detail. In the liquid resin composition of the present invention, (A) a liquid epoxy resin, (B) an aromatic amine-based curing agent, and (C) an inorganic filler are essential.

(A) Liquid epoxy resin As the epoxy resin in the present invention, any epoxy resin containing an epoxy group having two or more functional groups in one molecule can be used, and specifically, bisphenol A type. Examples include epoxy resins, bisphenol-type epoxy resins such as bisphenol F-type epoxy resins, naphthalene-type epoxy resins, novolac-type epoxy resins, and phenylglycidyl ether. Among these, use liquid epoxy resins at room temperature (25 ° C) Is preferred. In addition, the liquid epoxy resin of the present invention can be used alone or in combination of two or more of the above epoxy resins, but the viscosity at 25 ° C. is 800 Pa · s or less, particularly 500 Pa · s or less. It is preferable that it is liquid. In the present invention, the viscosity is a value measured at 25 ° C. by a rotational viscometer.

  In addition, the epoxy resin of the present invention contains the epoxy resin represented by the following structural formulas (1) and (2) alone or in combination with the above epoxy resin within a range not affecting the penetration property. Also good.

Here, R ⁵ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 3 carbon atoms, and examples of the monovalent hydrocarbon group include a methyl group and an ethyl group. And alkyl groups such as propyl group, alkenyl groups such as vinyl group and allyl group. X is an integer of 1 to 4, particularly 1 or 2.

  The epoxy resins represented by the structural formulas (1) and (2) are more preferably used alone or in combination with the above-described epoxy resin when it is desired to increase the Tg of the underfill material.

  Moreover, in order to reduce internal stress as an epoxy resin, preferably, the number of alkenyl groups of the alkenyl group-containing epoxy resin or phenol resin and silicon atoms in one molecule represented by the following average composition formula (3) is 20 to 400, It is preferable to blend a copolymer obtained by addition reaction with SiH groups of organopolysiloxane having 1 to 5 hydrogen atoms (SiH groups) bonded to silicon atoms.

H _a R ⁵ _b SiO _{(4-ab) / 2} (3)
(In the formula, R ⁵ is an unsubstituted or substituted monovalent hydrocarbon group, a is 0.01 to 0.1, b is 1.8 to 2.2, and 1.81 ≦ a + b ≦ 2.3. .)

The monovalent hydrocarbon group for R ⁵ is preferably a group having 1 to 10 carbon atoms, particularly 1 to 8 carbon atoms, and is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, or a tert-butyl group. , Alkyl groups such as hexyl group, octyl group and decyl group, alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group and hexenyl group, aryl groups such as phenyl group, xylyl group and tolyl group, benzyl group and phenyl group Fluoromethyl group, bromoethyl group, trifluoropropyl group, etc. in which some or all of the hydrogen atoms of these hydrocarbon groups are substituted with halogen atoms such as chlorine, fluorine, bromine, etc. And halogen-substituted monovalent hydrocarbon groups.

  As the above-mentioned copolymer, the following structural formula (4) is preferable.

In the above formula, R ⁵ is the same as above, and R ⁶ is —CH ₂ CH ₂ CH ₂ —, —OCH ₂ —CH (OH) —CH ₂ —O—CH ₂ CH ₂ CH ₂ — or —O—. CH ₂ CH ₂ CH ₂ —, and R ⁷ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 4 to 199, preferably 19 to 99, p is an integer of 1 to 10, and q is an integer of 1 to 10.

  By blending the above copolymer so that the diorganopolysiloxane unit is contained in an amount of 0 to 20% by mass, particularly 2 to 15% by mass, based on the whole (A) liquid epoxy resin, the stress can be further reduced. it can.

  The total chlorine content in the liquid epoxy resin is preferably 1,500 ppm or less, more preferably 1,000 ppm or less. Moreover, it is preferable that the extraction water chlorine in 20 hours in the 50% epoxy resin density | concentration at 100 degreeC is 10 ppm or less. If the total chlorine content exceeds 1,500 ppm or the extracted water chlorine exceeds 10 ppm, the reliability of the semiconductor element, particularly the moisture resistance, may be adversely affected.

(B) Aromatic amine curing agent The aromatic amine curing agent used as the curing agent in the present invention may be the following. Aromatic diaminodiphenylmethane compounds such as 3,3′-diethyl-4,4′-diaminophenylmethane, 3,3 ′, 5,5′-tetramethyl-4,4′-diaminophenylmethane, 3,3 ′ , 5,5′-tetraethyl-4,4′-diaminophenylmethane, 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene and the like. These may be used alone or in combination of two or more.

  In the above aromatic amine-based curing agent, if it is solid at room temperature, if it is blended as it is, the viscosity of the resin will increase and workability will be remarkably deteriorated. It is preferable. When melt-mixing with an epoxy resin, it is desirable to melt-mix for 1 to 2 hours in a temperature range of 70 to 150 ° C, preferably 70 to 120 ° C. If the mixing temperature is less than 70 ° C, the aromatic amine curing agent may not be sufficiently compatible, and if the temperature exceeds 150 ° C, it may react with the epoxy resin and increase the viscosity. Also, if the mixing time is less than 1 hour, the aromatic amine curing agent is not sufficiently compatible and may increase the viscosity, and if it exceeds 2 hours, it may react with the epoxy resin and increase the viscosity. .

  The total blending amount of the aromatic amine curing agent used in the present invention is the equivalent ratio of (A) liquid epoxy resin and (B) aromatic amine curing agent [(A) epoxy equivalent of liquid epoxy resin / (B) Amine equivalent of aromatic amine curing agent] is preferably 0.7 or more and 1.2 or less, particularly preferably 0.7 or more and 1.1 or less. If the equivalence ratio is less than 0.7, unreacted amino groups remain, and the glass transition temperature may be lowered or the adhesion may be lowered. On the other hand, if it exceeds 1.2, the cured product becomes hard and brittle, and cracks may occur during reflow.

(C) Inorganic filler In the present invention, various inorganic fillers are added to the inorganic filler for the purpose of reducing the expansion coefficient. Specific examples of the inorganic filler include fused silica, crystalline silica, alumina, boron nitride, ticker aluminum, ticker silicon, magnesia, magnesium silicate, aluminum and the like. Among them, spherical fused silica is desirable for reducing the viscosity.

  In order to increase the bond strength between the resin and the filler, the inorganic filler is preferably blended in advance with a surface treatment with a coupling agent such as a silane coupling agent or a titanate coupling agent. As such a coupling agent, epoxy silane such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, N Silane cups such as aminosilanes such as -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and mercaptosilanes such as γ-mercaptosilane It is preferable to use a ring agent. Here, the blending amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

  The average particle diameter of the inorganic filler (C) is the height of the protruding electrode after being connected, that is, the value obtained by subtracting the diameter of the protruding electrode from the gap height or pitch between the protruding electrodes, that is, the smaller value of the gap width. On the other hand, it is desirable that the average particle size is 1/10 or less and the maximum particle size is also 1/2 or less because the filling property can be particularly improved. If this dimension is exceeded, voids may be generated due to reduced fluidity, or a layer with less filler is formed near the semiconductor chip interface due to filler sedimentation, and the thermal expansion coefficient of that part is reduced. This is because of the problem.

  The average particle diameter of the inorganic filler (particularly spherical silica) is 0.3 to 20 μm, preferably 0.5 to 10 μm. If it is less than 0.3 μm, the surface area of the filler increases, so the fluidity decreases. On the other hand, when the thickness is 20 μm or more, the filler is clogged when settling or filling the gap, and there is a risk of voids.

  The inorganic filler (C) is blended in order to reduce the thermal expansion coefficient after curing, but in the case of 30% by mass or less with respect to the total amount of the components (A) to (C), the thermal expansion coefficient. Is large and has a low ability to protect during the solder cooling cycle as a protruding electrode, desirably 50 mass% or more, more desirably 60 mass% or more, but addition of 83 mass% or more is difficult due to the workability of resin injection. It is. Accordingly, the inorganic filler (C) is 30 to 83 mass%, preferably 50 to 75 mass%, based on the total amount of the components (A) to (C).

(D) Curing accelerator Although it is not an essential component, (D) a curing accelerator can be added to the liquid resin composition of the present invention. When the reaction start temperature of the epoxy resin and aromatic amine curing agent is higher than 160 ° C., it is necessary to add it. If it exceeds 160 ° C, there is a concern that the flux residue cannot be lifted. Moreover, when it floats, the metal oxide layer on the side surface of the solder may be reduced to generate water and generate voids. The flux residue mentioned here reacts with the epoxy resin to form a solid when the underfill material is injected or cured.

  As the (D) curing accelerator, carboxylic acids can be preferably used. For example, benzoic acid, 4′-ethylbiphenyl-4-carboxylic acid, 4′-propylbiphenyl-4-carboxylic acid, 4′-butyl is used. Biphenyl-4-carboxylic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, Pentadecanedioic acid, hexadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, eicosanedioic acid, methylmalonic acid, ethylmalonic acid, n-propylmalonic acid, n-butylmalonic acid, methylsuccinic acid, ethylsuccinic acid, 1,1, 3,5-tetramethyloctyl succinic acid, maleic acid, fumaric acid, citraconic acid, γ-methyl citracco Acid, mesaconic acid, γ-methyl mesaconic acid, itaconic acid, glutaconic acid, hexahydrophthalic acid, hexahydroisophthalic acid, hexahydroterephthalic acid, methylhexahydrophthalic acid, methylhexahydroisophthalic acid, methylhexahydroterephthalic acid, cyclohexene -1,2-dicarboxylic acid, cyclohexene-1,6-dicarboxylic acid, cyclohexene-3,4-dicarboxylic acid, cyclohexene-4,5-dicarboxylic acid, cyclohexene-1,3-dicarboxylic acid, cyclohexene-1,5- Dicarboxylic acid and cyclohexene-3,5-dicarboxylic acid, cyclohexene-1,4-dicarboxylic acid, cyclohexene-3,6-dicarboxylic acid, 1,3-cyclohexadiene-1,2-dicarboxylic acid, 1,3-cyclohexadiene -1,6-dical Acid, 1,3-cyclohexadiene-2,3-dicarboxylic acid, 1,3-cyclohexadiene-5,6-dicarboxylic acid, 1,4-cyclohexadiene-1,2-dicarboxylic acid, 1,4-cyclo Hexadiene-1,6-dicarboxylic acid, 1,3-cyclohexadiene-1,3-dicarboxylic acid, 1,3-cyclohexadiene-3,5-dicarboxylic acid, 1,3-cyclohexadiene-1,4-dicarboxylic acid 1,3-cyclohexadiene-2,5-dicarboxylic acid, 1,4-cyclohexadiene-1,4-dicarboxylic acid, 1,4-cyclohexadiene-3,6-dicarboxylic acid, methyltetrahydrophthalic acid, methylhexa Hydrophthalic acid, hexahydrophthalic acid, methyl hymic acid, pyromellitic acid, benzophenone tetracarboxylic acid, 3,3'-4 4'-biphenyltetracarboxylic bis benzophenonetetracarboxylic acid, bis (3,4-carboxyphenyl) methane, 2,2-bis (3,4-carboxyphenyl) propane and the like can be used. Phenolic acids such as benzoic acid, salicylic acid, and phthalic acid are preferred, and those obtained by microencapsulating these phenolic acids with acrylic or the like are more preferred because they can prevent shortening of the usable time of the resin.

  The (D) curing accelerator is required to be used when the curing start temperature of the underfill material composed of the components (A) to (C) is 160 ° C. or higher, and the curing start temperature is 160 ° C. When it becomes the above, it is preferable to add as an auxiliary material for lowering the curing start temperature. Therefore, the addition amount at that time is 0 to 5% by mass, preferably 0 to 2% by mass, based on the underfill material composed of the components (A) to (C) according to the curing start temperature.

(E) Other additives In the liquid resin composition of the present invention, if necessary, pigments such as carbon-functional silane for improving adhesion, carbon black and other pigments, dyes, antioxidants, diluents and other additives are added to the present invention. It can mix | blend in the range which does not impair the objective. However, in the present invention, it is preferable not to add an alkoxy-based silane coupling agent as a carbon-functional silane for improving adhesion other than the use as a surface treatment agent. In particular, when used as an underfill material, if an alkoxy-based silane coupling agent is blended even in a small amount, it may cause voids.

  In the epoxy resin composition of the present invention, for example, the epoxy resin and the curing agent are stirred, dissolved, mixed, and dispersed simultaneously or separately with heat treatment as necessary. There are no particular limitations on the apparatus for mixing, stirring, dispersing, etc., in these mixtures, but a raikai machine, three rolls, ball mill, planetary mixer, etc. equipped with stirring and heating devices can be used. You may combine these apparatuses suitably.

  In the present invention, the viscosity of the liquid epoxy resin composition used as the sealing material is preferably 1,000 Pa · s or less, particularly 500 Pa · s or less at 25 ° C. The molding conditions can be conventional methods, but preferably 100 to 120 ° C. for 0.2 hours or longer, particularly 0.4 to 0.6 hours, and then 130 to 170 ° C. for 1 hour or longer, particularly. Perform a heat oven cure under conditions of 2-3 hours. When heating at 100 to 120 ° C. is less than 0.2 hours, voids may occur after curing. Further, if the heating at 130 to 170 ° C. is less than 1 hour, sufficient cured product characteristics may not be obtained.

Method for Measuring Reaction Start Temperature The reaction start temperature in the present invention is measured as an onset temperature of an exothermic curve in differential scanning calorimetry (commonly called DSC).
Here, the onset (reaction start temperature) temperature is defined as follows. About 10 mg of the liquid resin composition (underfill agent) used in the test is collected in an aluminum pan and heated at 10 ° C./min with a differential scanning calorimeter (DSC821 manufactured by METLER) to obtain a DSC curve. As shown in FIG. 1, the DSC exothermic curve was defined as the onset temperature at the intersection of the tangent line and the baseline defined by a straight line at the point where the peak of the first-order derivative was obtained.

  The flux residue has a viscosity lower than the viscosity of the underfill material at a high temperature of 100 ° C. or higher, that is, the temperature at which the underfill material is injected or cured, and forms a solid layer by reacting with the epoxy. . It is difficult for the filler to enter the layer, resulting in a layer with almost no filler. When the reaction start temperature of the epoxy resin composition is low, that is, when the reaction is fast, the reaction between the epoxy and the flux starts early, and the floating layer can be prevented. Further, since the reaction product of the flux and the epoxy does not have the flux activity, the reduction of the oxide layer on the solder surface is suppressed, so that the released water can be reduced, and as a result, the void can be reduced.

  The curing start temperature is preferably 160 ° C. or lower, but more preferably 155 ° C. or lower. In addition, the underfill material is cured as described above to seal the element, but it is also possible to add a curing accelerator for the purpose of simply reducing the cost of the process. Carboxylic acids can be suitably used as usable curing accelerators, but those that are microencapsulated with acrylic or the like are more preferable because they can prevent shortening the pot life of the resin.

  The liquid epoxy resin composition of the present invention is stirred, for example, by adding a liquid epoxy resin, an aromatic amine curing agent, a curing accelerator, a filler and other additives at the same time or separately, if necessary with heat treatment. , Dissolved, mixed, and dispersed. The apparatus for mixing, stirring, dispersing and the like is not particularly limited, and a lykai machine, a three roll, a ball mill, a planetary mixer and the like equipped with a stirring and heating device can be used. Moreover, you may use combining these apparatuses suitably.

  In the present invention, the viscosity of the liquid epoxy resin composition used as the sealing material is preferably 100 Pa · s or less, particularly 5 to 80 Pa · s at 25 ° C.

  A known method can be used as a method of sealing a flip chip type semiconductor element using the liquid sealing resin composition of the present invention and manufacturing a semiconductor device.

  Examples of the present invention and comparative examples will be described below in detail, but the present invention is not limited to the following examples.

  Evaluation is a flip chip evaluation kit manufactured by Hitachi Ultra LSI Co., Ltd. JTEG Phase 2E175 Bump height 50 μm, Pitch 175 μm, 15 mm × 15 mm × 0.6 mmt Solder composition (Sn-3.0Ag-0.5Cu) as a substrate JKIT TYPE VI The number of electrodes is 5,184, and TSF-6502 (manufactured by Kester) or Gelflux 2000BT (manufactured by Cobar) is applied to the substrate and the protruding electrode part of the element as a flux and positioned with a flip chip bonder. Further, solder connection was performed using an IR reflow furnace. Also, as a reference, when positioning with a flip chip bonder without using a flux, evaluation was also performed on a package that was heated to 260 ° C. and connected.

[Examples 1-3, Comparative Examples 1-3]

  Six types of resin compositions were obtained by uniformly kneading the components shown in Table 1 above with three rolls. Here, the reaction start temperature was measured using a differential scanning calorimeter (DSC821 manufactured by METTLER) at a temperature rising rate of 10 ° C./min. The measured DSC chart is shown in FIG.

The test shown below was done using these resin compositions.
The materials used here are as follows.
(A) Liquid epoxy resin epoxy resin A: bisphenol F type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., RE303S-L)
Epoxy resin B: Trifunctional epoxy resin represented by the following formula (3) (Japan Epoxy Resin Co., Ltd., Epicoat 630H)

Copolymer: addition reaction product of a compound of the following formula (5) and a compound of the following formula (6)

(B) Curing agent Curing agent A: Diethyldiaminodiphenylmethane (Kayahard AA manufactured by Nippon Kayaku Co., Ltd.)
Curing agent B: diethyltoluenediamine (molecular weight; 178)

(C) Inorganic filler spherical silica: true spherical fused silica having an average particle size of 2.0 μm and a maximum particle size of 15 μm (manufactured by Admatechs)
(D) Curing accelerator Curing accelerator: Polymer of methyl methacrylate containing 20% by mass of salicylic acid (E) Other additive Silane coupling agent: γ-glycidoxypropyltrimethoxysilane (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) )
Carbon black: Denka Black (manufactured by Denki Kagaku Kogyo)
Diluent: ethylene glycol monobutyl ether acetate

  The above-mentioned semiconductor package is heated on a hot plate at 110 ° C., and kneaded on one side of the semiconductor element, and the resin composition shown in Table 1 above is dispensed and filled, and the resin is cured in an oven at 160 ° C. for 120 minutes. As a result, a semiconductor device was obtained.

The semiconductor device obtained above was evaluated by the following method.
[Void observation]
The occurrence of voids was observed using an ultrasonic cross-sectional observation apparatus (Quantum 350 manufactured by SONIX).
[Section observation]
The obtained semiconductor device was subjected to cross-sectional polishing, and the floating of the flux layer was observed.
The results are shown in Table 2.
The package used here is connected using the following flux.
Package A: TSF6502 (manufactured by KESTER)
Package B: Gelflux 2000BT (COBER)
For reference, package C: a package that is heated and connected to 260 ° C when positioning with a flip chip bonder without using flux

ここにおける断面観察においてフラックスの浮遊層無しの状態の模式図を図１に、浮き有りの模式図を図２にしめすが、参考に行ったパッケージCの断面はフラックスを用いていないためフラックス層自体が見られない。

In the cross-sectional observation here, the schematic diagram of the state without the floating layer of the flux is shown in FIG. 1, and the schematic diagram of the floating state is shown in FIG. Is not seen.

As is apparent from the results shown in the table, in Examples 1 to 3, there is no floating of the flux layer and the voidability is improved. On the other hand, in the comparative example, there are many voids and the flux layer is lifted. Moreover, the package which did not use the flux performed as a reference resulted in no generation of voids. From this result, it is considered that the void in the semiconductor device is caused by the residue of the flux, but the present invention has the effect of preventing it.

It is drawing which shows the measuring method of reaction start temperature. 2 is a DSC chart of the composition shown in Example 1. It is sectional drawing which shows an example of the state without the flux floating layer of this invention. It is sectional drawing which shows an example of a state with a flux floating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Flux layer 3 Solder resist 4 Protrusion electrode (solder)
5 Substrate 6 Substrate electrode

Claims (4)

  (A) A liquid epoxy resin, (B) an aromatic amine-based curing agent, and (C) a liquid resin composition for underfill which must contain an inorganic filler, and curing the composition. An underfill material characterized in that the reaction start temperature is adjusted to 160 ° C. or lower.   Equivalent ratio of (A) liquid epoxy resin and (B) aromatic amine curing agent [(A) epoxy equivalent of liquid epoxy resin / (B) amine equivalent of aromatic amine curing agent] is 0.7 or more and 1 The liquid resin composition for underfill according to claim 1, which is .2 or less.   The liquid resin composition for underfill according to claim 1 or 2, wherein (C) the inorganic filler is 30% by mass or more in the total amount of the resin composition.   A flip chip type semiconductor device in which the liquid epoxy resin composition according to any one of claims 1 to 3 is injected into a gap between die substrates of a flip chip type semiconductor device, cured and sealed.

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