JP2022172745A - Method for manufacturing semiconductor device - Google Patents

Abstract

To provide a semiconductor device whose warpage is small and which has excellent reliability.SOLUTION: A method for manufacturing a semiconductor device comprises sealing the top of a substrate having two or more semiconductor elements mounted thereon by molding a thermosetting resin composition. The thermosetting resin composition contains a cyanate ester compound having two or more cyanato groups in one molecule, a curing agent, and an inorganic filler. A molding temperature during the sealing by molding is equal to or lower than the glass transition temperature of a cured product of the thermosetting resin composition. The molding temperature during the sealing by molding is 140°C or higher. A molding method is either transfer molding or compression molding.SELECTED DRAWING: None

Description

The present invention relates to a method of manufacturing a semiconductor device.

2. Description of the Related Art In recent years, mobile information communication terminals such as smartphones and tablets are equipped with semiconductor devices that are thin, small, multifunctional, and capable of high-speed processing so that large amounts of information can be processed at high speed. In such a semiconductor device, semiconductor elements are connected in multiple layers using TSV (through silicon via) technology, flip-chip connected to an 8-inch to 12-inch silicon interposer, and then connected in multiple layers. Each interposer on which a plurality of semiconductor elements are mounted is sealed with a thermosetting resin, unnecessary cured resin on the semiconductor elements is polished, and individualized (Patent Document 1).

In the manufacture of semiconductor devices, even under the present circumstances, a substrate such as a small-diameter wafer can be molded and sealed without any major problems. However, in the molding of 8-inch or more, and in recent years, 20-inch wafers or panels exceeding 20 inches, if the silicon interposer is entirely sealed with thermosetting resin, the difference in thermal expansion coefficient between the silicon wafer and thermosetting resin A large warp occurs in the silicon wafer, and since it cannot be applied to the subsequent polishing process and singulation process, prevention of warpage is a major technical issue.

In order to solve such problems, conventionally, a composition using an epoxy resin and a curing agent such as an acid anhydride or phenolic resin is filled with 85% by mass or more of a filler, and rubber or rubber is used for stress relaxation. A sealing material containing a thermoplastic resin and a low-elasticity resin material have been used (Patent Documents 2 and 3). With such a composition, warpage of the wafer occurs due to the thermal history of the 3D packaging process, and the warpage causes damage to the semiconductor elements or cracking of the wafer itself. On the other hand, conventional low-elasticity resin materials, typified by silicone compounds, are soft and have problems such as resin clogging during polishing and resin cracks during reliability tests.

JP 2014-229771 A JP 2012-209453 A JP 2016-148054 A

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable semiconductor device that is less warped.

As a result of intensive research to solve the above problems, the present inventors found that the above objects can be achieved by setting the molding temperature at the time of molding sealing to the glass transition temperature of the thermosetting resin composition or less. completed the invention.

That is, the present invention provides the following method for manufacturing a semiconductor device.

（式中、Ｒ¹及びＲ²は水素原子または炭素数１～４のアルキル基を示し、Ｒ³は単結合又は下記式

で表される２価の基のいずれかを示す。Ｒ⁴は水素原子またはメチルであり、ｎ＝０～１０の整数である。）
で示されるシアネートエステル化合物である［１］～［６］のいずれか１項に記載の半導体装置の製造方法。

［８］
硬化剤がアミン系硬化剤、フェノール系硬化剤、及び水物系硬化剤から選ばれる１種以上である［１］～［７］のいずれか１項に記載の半導体装置の製造方法。

［９］
無機充填材の含有率が、前記樹脂組成物全体の７０～９５質量％である［１］～［８］のいずれか１項に記載の半導体装置の製造方法。

［１０］
さらに硬化促進剤を含む［１］～［９］のいずれか１項に記載の半導体装置の製造方法。

［１１］
前記基板が、シリコンウエハ、セラミック基板、及び基板のいずれかである［１］～［１０］のいずれか１項に記載の半導体装置の製造方法。
[1]
A method for manufacturing a semiconductor device in which a substrate on which two or more semiconductor elements are mounted is molded and sealed with a thermosetting resin composition,
The thermosetting resin composition contains a cyanate ester compound having two or more cyanato groups in one molecule; a curing agent, and an inorganic filler, and the molding temperature at the time of molding sealing is the thermosetting A semiconductor device having a glass transition temperature of a cured product of a resin composition or lower, a molding temperature of 140° C. or higher during molding and sealing, and a molding method of either transfer molding or compression molding. manufacturing method.

[2]
The average thermal expansion coefficient of the cured product of the thermosetting resin composition in the temperature range below the glass transition temperature is −20% or more and +10% or less of the average thermal expansion coefficient of the substrate in the same temperature range [1] A method of manufacturing the semiconductor device according to 1.

[3]
The method for manufacturing a semiconductor device according to [1] or [2], wherein the thermosetting resin composition has a melt viscosity of 0.1 to 100 Pa·s at 175°C.

[4]
The method for manufacturing a semiconductor device according to any one of [1] to [3], wherein the thermosetting resin composition has a gelling time of 10 seconds to 180 seconds at 175°C.

[5]
The method for manufacturing a semiconductor device according to any one of [1] to [4], wherein the uncured shape of the thermosetting resin composition is tablet-like, granular, or sheet-like.

[6]
The method for manufacturing a semiconductor device according to any one of [1] to [5], wherein the thermosetting resin composition is in the form of a sheet with a thickness of 0.1 mm to 10 mm.

[7]
The cyanate ester compound has the following formula (1)

(wherein R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ represents a single bond or

Any one of the divalent groups represented by R ⁴ is a hydrogen atom or methyl and n is an integer of 0-10. )
The method for manufacturing a semiconductor device according to any one of [1] to [6], which is a cyanate ester compound represented by

[8]
The method for manufacturing a semiconductor device according to any one of [1] to [7], wherein the curing agent is one or more selected from amine-based curing agents, phenol-based curing agents, and water-based curing agents.

[9]
The method for manufacturing a semiconductor device according to any one of [1] to [8], wherein the content of the inorganic filler is 70 to 95 mass % of the entire resin composition.

[10]
The method for manufacturing a semiconductor device according to any one of [1] to [9], further comprising a curing accelerator.

[11]
The method of manufacturing a semiconductor device according to any one of [1] to [10], wherein the substrate is any one of a silicon wafer, a ceramic substrate, and a substrate.

According to the method for manufacturing a semiconductor device of the present invention, it is possible to obtain a highly reliable semiconductor device with very little warpage when molded and sealed with a thermosetting resin composition, regardless of the type of substrate.

It is the figure which showed the manufacturing method of a semiconductor device. It is the figure which showed the determination method of glass transition temperature.

The method for manufacturing a semiconductor device according to the present invention will be described in detail below, but the present invention is not limited to these.

[Semiconductor device]
An example of a semiconductor device manufactured by the manufacturing method of the present invention is shown in FIG. This semiconductor device is obtained by sealing a substrate 3 on which two or more semiconductor elements 31 are mounted with a thermosetting resin composition 1 (see FIGS. 1A and 1B). This semiconductor device can also be separated into individual pieces by dicing (see FIGS. 1(C) and 1(D)).
In this specification, the substrate 3 on which a semiconductor element is mounted means a substrate 32 using various wafers such as a silicon wafer, a ceramic substrate, an organic substrate, a glass substrate, a metal substrate, a plastic substrate, or the like, or a substrate on which a semiconductor element is mounted. It includes an array of semiconductor devices arranged in a row or the like. A wafer on which the semiconductor elements are formed is also regarded as a type of substrate on which the semiconductor elements are mounted.

The semiconductor device manufactured by the manufacturing method of the present invention has two or more semiconductor elements, preferably 10 to 1,000 semiconductor element mounting surfaces of a substrate, or two or more semiconductor elements, preferably 50 to 700 semiconductor elements. It is a semiconductor device in which the semiconductor element formation surface of the formed wafer is molded and sealed with a cured product of a thermosetting resin composition having a glass transition temperature equal to or higher than the molding temperature. The method of arranging the semiconductor elements is not particularly limited, and may be appropriately determined according to the size of the semiconductor elements, the required number, productivity, and the like. As a substrate on which semiconductor elements are mounted, for example, a substrate (semiconductor element mounting substrate) in which two or more semiconductor elements 31 in FIG. 3).

[Method for manufacturing a semiconductor device]
A semiconductor device manufactured by the manufacturing method of the present invention can be implemented by molding and sealing a substrate 3 on which two or more semiconductor elements 31 are mounted with a thermosetting resin composition 1 described in detail below (FIG. 1 ( A) and (B)). At that time, the molding temperature at the time of molding and sealing is set to the glass transition temperature of the cured product of the thermosetting resin composition or less.

In the present invention, the glass transition temperature (Tg) refers to the value determined by the TMA method. As a measurement by the TMA method, the cured product obtained by curing the thermosetting resin composition was processed into test pieces of 5 × 5 × 15 mm, and then the test pieces were measured with a thermal dilatometer TMA8140C (manufactured by Rigaku). Then, the heating program is set to a heating rate of 5°C/min and a constant load of 19.6 mN is applied, and then the dimensional change of the test piece is measured between 25°C and 300°C. The relationship between this dimensional change and temperature is plotted on a graph (an example of the graph is shown in FIG. 2). From the graph of dimensional change and temperature obtained in this manner, the glass transition temperature can be determined by the method for determining the glass transition temperature described below.

As shown in FIG. 2, two arbitrary temperature points at which the tangent line of the dimensional change-temperature curve can be obtained below the temperature of the inflection point are T1 and T2, and any arbitrary temperature at which the same tangent line can be obtained above the temperature of the inflection point. The two temperature points are T1' and T2'. Dimensional changes at T1 and T2 are D1 and D2, respectively, a straight line connecting points (T1, D1) and points (T2, D2), and dimensional changes at T1′ and T2′ are D1′ and D2′, respectively. A glass transition temperature (Tg) is defined as an intersection of a straight line connecting points (T1′, D1′) and points (T2′, D2′).

General molding methods for the thermosetting resin composition used in the present invention include transfer molding and compression molding. In the transfer molding method, a transfer molding machine is used at a molding pressure of 5 to 20 N/mm ² , a molding temperature of 140 to 250° C. and a molding time of 30 to 500 seconds, preferably a molding temperature of 175 to 225° C. and a molding time of 30 to 180 seconds. conduct. In the compression molding method, a compression molding machine is used at a molding temperature of 140 to 250° C. for a molding time of 30 to 600 seconds, preferably at a molding temperature of 175 to 225° C. for a molding time of 120 to 300 seconds. Further, in either molding method, post-curing may be carried out at preferably 150-225° C., more preferably 160-200° C., for 0.5-20 hours.

In this specification, the average thermal expansion coefficient is calculated from the results of thermomechanical analysis of the cured product of the thermosetting resin composition under the same conditions as the glass transition temperature measurement, and the temperature range from 40 ° C. to 80 ° C. It is the average value of the coefficient of linear expansion.
The average thermal expansion coefficient at 40°C to 80°C of the cured product of the thermosetting resin composition is -20% relative to the average thermal expansion coefficient at 40°C to 80°C of the substrate on which two or more semiconductor elements are arranged. It is preferably from -10% to +10%, more preferably from -15% to +8% or less. When the average coefficient of thermal expansion is within the above range, the difference in coefficient of thermal expansion between the semiconductor element and the insulating substrate becomes small, and it becomes possible to suppress the warpage of the wafer after sealing.

As used herein, the viscosity of the thermosetting resin composition at 175° C. refers to a value measured using a rheometer according to JIS K 7244-10:2005. As the rheometer, for example, HR-2 (manufactured by TA Instruments) is used.
The melt viscosity of the thermosetting resin composition at 175° C. is preferably 0.1 Pa·s to 100 Pa·s, more preferably 0.5 Pa·s to 70 Pa·s, and particularly preferably 1 Pa·s to 50 Pa·s. .

The gelling time of the thermosetting resin composition at 175° C. is preferably 5 to 240 seconds, more preferably 5 to 120 seconds. If it is 20 seconds or longer, the filling property does not deteriorate, and there is no fear of generating internal voids or surface voids.

[Thermosetting resin composition]
The thermosetting resin composition used in the present invention is a resin composition in which the glass transition temperature of the cured product of the thermosetting resin composition is higher than the molding temperature when molded and sealed. The glass transition temperature of the cured product of the thermosetting resin composition is preferably +5 to +120°C, more preferably +10 to +100°C, and +15 to +80°C relative to the molding temperature. is more preferred. When the glass transition temperature is within the above range, warpage between the cured product and the substrate after molding and sealing can be reduced.

As the thermosetting resin used in the thermosetting resin composition, generally known ones can be used, and examples thereof include epoxy resins, maleimide resins, cyanate ester compounds, and the like. These resins can be used individually by 1 type or in combination of 2 or more types.

Epoxy resin The type of epoxy resin is not particularly limited, and generally known ones can be used. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, and bisphenol F novolak type epoxy resin. , stilbene type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, trisphenolalkane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenylaralkyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type Epoxy resins, alicyclic epoxy resins, silicone-modified epoxy resins, butadiene-modified epoxy resins, diglycidyl ether compounds of polyfunctional phenols and polycyclic aromatics such as anthracene, and phosphorus-containing epoxy resins obtained by introducing phosphorus compounds into these, etc. is mentioned. These can be used individually by 1 type or in combination of 2 or more types.

A curing agent may also be used for the purpose of curing the epoxy resin. The type of curing agent is not particularly limited, and generally known ones can be used. Curing agents for epoxy resins include amine-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, and thiol-based curing agents. From the viewpoint of moldability and heat resistance, the curing agent is preferably an amine curing agent, a phenolic curing agent, or an acid anhydride curing agent.

Amine curing agents include 3,3′-diethyl-4,4′-diaminophenylmethane, 3,3′,5,5′-tetramethyl-4,4′-diaminophenylmethane, 3,3′, aromatic diaminodiphenylmethane compounds such as 5,5'-tetraethyl-4,4'-diaminophenylmethane; 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene; It can be used individually by 1 type or in combination of 2 or more types.

When an amine-based curing agent is used as the curing agent, the molar ratio of active hydrogen contained in the curing agent to 1 mol of epoxy groups contained in the epoxy resin is preferably 0.5 to 1.5, more preferably 0.8 to 1. .2 is more preferred. If the molar ratio is less than 0.5, unreacted epoxy resin may remain, resulting in lower glass transition temperature or lower adhesion. On the other hand, if the molar ratio exceeds 1.5, the moisture absorption of the cured product may increase.

Examples of phenol curing agents include phenol novolac resin; naphthalene ring-containing phenol resin; aralkyl-type phenol resin; trisphenolmethane-type phenol resin; biphenyl skeleton-containing aralkyl-type phenol resin; cyclic phenol resin; naphthalene ring-containing phenol resin; resorcinol-type phenol resin; allyl group-containing phenol resin; More than one species can be used in combination.

When a phenolic resin is used as the curing agent, the molar ratio of phenolic hydroxyl groups contained in the curing agent to 1 mol of epoxy groups contained in the epoxy resin is preferably 0.5 to 1.5, more preferably 0.8 to 1.5. 2 is more preferred. If the molar ratio is less than 0.5, unreacted epoxy resin may remain, resulting in lower glass transition temperature or lower adhesion. On the other hand, if the molar ratio exceeds 1.5, the moisture absorption of the cured product may increase.

Examples of acid anhydride curing agents include 3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic anhydride, 1-isopropyl-4-methyl- Bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhimic anhydride, pyromellitic acid Dianhydride, maleated alloocimene, benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetrabisbenzophenonetetracarboxylic dianhydride, (3,4-dicarboxyphenyl) ether dianhydride , bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride and the like, and these may be used alone or in combination of two or more. It can be used in combination.

When an acid anhydride curing agent is used as the curing agent, the molar ratio of acid anhydride contained in the curing agent to 1 mol of epoxy groups contained in the epoxy resin is preferably 0.5 to 1.5, and 0.5 to 1.5. 8 to 1.2 are more preferred. If the molar ratio is less than 0.5, unreacted epoxy resin may remain, resulting in lower glass transition temperature or lower adhesion. On the other hand, if the molar ratio exceeds 1.5, the moisture absorption of the cured product may increase.

Maleimide Resin The maleimide resin is not particularly limited as long as it has one or more maleimide groups in one molecule, and generally known ones can be used. Examples of maleimide resins include 4,4-diphenylmethanebismaleimide, phenylmethanemaleimide, m-phenylenebismaleimide, 2,2-bis(4-(4-maleimidophenoxy)-phenyl)propane, 3,3-dimethyl- 5,5-diethyl-4,4-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4-diphenyletherbismaleimide Maleimide, 4,4-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, novolac-type maleimide compound, biphenylaralkyl-type maleimide, diamine dimer acid type maleimide, a prepolymer of the maleimide resin, or a prepolymer of a maleimide resin and an amine compound. These maleimide compounds can be used singly or in combination of two or more. Among these, novolac-type maleimide compounds and biphenylaralkyl-type bismaleimide compounds are preferred. The use of such a maleimide compound tends to further improve the heat resistance.

A curing agent may also be used for the purpose of curing the maleimide resin. The type of curing agent is not particularly limited, and generally known ones can be used. Curing agents for maleimide resins include amine-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, thiol-based curing agents, radical polymerization initiators, and the like. From the viewpoint of moldability and heat resistance, the curing agent is preferably a phenol-based curing agent or a radical polymerization initiator.

Examples of phenol curing agents include phenol novolac resins; naphthalene ring-containing phenol resins; aralkyl-type phenol resins; trisphenolalkane-type phenol resins; biphenyl skeleton-containing aralkyl-type phenol resins; cyclic phenol resin; naphthalene ring-containing phenol resin; resorcinol-type phenol resin; allyl group-containing phenol resin; More than one species can be used in combination. Moreover, it is preferable to have one or more allyl groups or propenyl groups in the skeleton of the phenol curing agent.

When a phenolic curing agent is used as the curing agent, the molar ratio of hydroxyl groups contained in the curing agent to 1 mol of maleimide groups contained in the maleimide resin is preferably 0.5 to 1.5, more preferably 0.8 to 1.2. is more preferred. If the molar ratio is less than 0.5, the resulting cured product may become brittle. On the other hand, if the molar ratio exceeds 1.5, the glass transition temperature of the cured product may decrease.

Examples of radical polymerization initiators include dicumyl peroxide, t-hexyl hydroperoxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, α,α'-bis(t- butylperoxy) diisopropylbenzene, t-butylcumyl peroxide, di-t-butylperoxide and the like, and these can be used alone or in combination of two or more.
The amount of the radical polymerization initiator used is preferably 0.2 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the maleimide resin.

Cyanate ester compound The cyanate ester compound is not particularly limited as long as it has two or more cyanato groups in one molecule, and generally known compounds can be used. Examples of cyanate ester compounds include 1,1-bis(4-cyanatophenyl)ethane, bis(3-methyl-4-cyanatophenyl)methane, bis(3-ethyl-4-cyanatophenyl)methane, bis (3,5-dimethyl-4-cyanatophenyl)methane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanatophenyl)-1,1,1,3, Bisphenol-type cyanate esters such as 3,3-hexafluoropropane, diallylbisphenol A-type cyanate ester, diallylbisphenol F-type cyanate ester; 2,2'-dicyanatobiphenyl, 4,4'-dicyanatobiphenyl, 3,3' ,5,5′-tetramethyl-4,4′-dicyanatobiphenyl and other biphenyl-type cyanate esters; 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 2-tert-butyl-1,4- Dicyanatobenzene, 2,4-dimethyl-1,3-dicyanatobenzene, 2,5-di-tert-butyl-1,4-dicyanatobenzene, tetramethyl-1,4-dicyanatobenzene, 1,3 ,5-tricyanatobenzene; 1,3-dicyanatonaphthalene, 1,4-dicyanatonaphthalene, 1,5-dicyanatonaphthalene, 1,6-dicyanatonaphthalene, 1,8-dicyanato cyanatonaphthalene such as naphthalene, 2,6-dicyanatonaphthalene, 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene; bis(4-cyanatophenyl) ether, 4,4′-(1 ,3-phenylenediisopropylidene)diphenylcyanate, bis(4-cyanatophenyl)thioether, bis(4-cyanatophenyl)sulfone. Among these, 1,1-bis(4-cyanatophenyl)ethane, diallylbisphenol A-type cyanate ester and diallylbisphenol F-type cyanate ester are preferable, and 1,1-bis(4-cyanatophenyl)ethane and diallyl Bisphenol F-type cyanate ester is more preferred. These cyanate ester compounds can be used singly or in combination of two or more.

一般式（１）中、Ｒ¹及びＲ²は、それぞれ独立に水素原子または炭素数１～４のアルキル基である。一般式（１）中、Ｒ¹及びＲ²としては、水素原子、メチル基、エチル基が好ましく、水素原子、メチル基が特に好ましい。Ｒ³は単結合又は下記の各式で表される基から選択されるいずれか１つの２価の基である。ｎは０～１０の整数であり、好ましくはｎは０～５、より好ましくはｎは１～４である。

上記式中Ｒ⁴は水素原子またはメチルである。
Moreover, as the cyanate ester compound, one or more cyanate ester compounds selected from compounds represented by the following general formula (1) may be used.

In general formula (1), R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In general formula (1), R ¹ and R ² are preferably a hydrogen atom, a methyl group or an ethyl group, particularly preferably a hydrogen atom or a methyl group. R ³ is a single bond or any one divalent group selected from groups represented by the following formulas. n is an integer of 0-10, preferably n is 0-5, more preferably n is 1-4.

In the above formula, ^R4 is a hydrogen atom or methyl.

Specific examples of the compound represented by the general formula (1) include BisE type cyanate ester compounds, novolac type cyanate ester compounds, and the like.

A curing agent may also be used for the purpose of curing the cyanate ester compound. The type of curing agent is not particularly limited, and generally known ones can be used. Curing agents for cyanate ester compounds include amine-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, and thiol-based curing agents. From the viewpoint of moldability and heat resistance, the curing agent is preferably an amine curing agent, a phenolic curing agent, or an acid anhydride curing agent.

Amine curing agents include 3,3′-diethyl-4,4′-diaminophenylmethane, 3,3′,5,5′-tetramethyl-4,4′-diaminophenylmethane, 3,3′, aromatic diaminodiphenylmethane compounds such as 5,5'-tetraethyl-4,4'-diaminophenylmethane; 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene; It can be used individually by 1 type or in combination of 2 or more types.

When an amine-based curing agent is used as the curing agent, the amount of the amine-based curing agent used is preferably 0.2 to 30 parts by mass, preferably 0.5 to 20 parts by mass, per 100 parts by mass of the cyanate ester compound. parts is more preferred, and 1.0 to 10 parts by mass is even more preferred. If the amount of the amine-based curing agent used is less than 0.2 parts by mass, unreacted cyanate ester compounds may remain, resulting in a decrease in glass transition temperature or a decrease in adhesion. On the other hand, if the amount of the amine-based curing agent used exceeds 30 parts by mass, the moisture absorption of the cured product may increase.

Examples of phenol curing agents include phenol novolac resin; naphthalene ring-containing phenol resin; aralkyl-type phenol resin; trisphenolmethane-type phenol resin; biphenyl skeleton-containing aralkyl-type phenol resin; cyclic phenol resin; naphthalene ring-containing phenol resin; resorcinol-type phenol resin; allyl group-containing phenol resin; More than one species can be used in combination.

When using a phenol curing agent as a curing agent, the amount of the phenol curing agent used is preferably 0.2 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, per 100 parts by mass of the cyanate ester compound. Preferably, 1.0 to 10 parts by mass is more preferable. If the amount of the phenol curing agent used is less than 0.2 parts by mass, unreacted cyanate ester compounds may remain, resulting in a decrease in glass transition temperature or a decrease in adhesion. On the other hand, if the amount of the phenol curing agent used exceeds 30 parts by mass, the storage stability may be poor and the glass transition temperature of the cured product may be lowered.

Examples of acid anhydride curing agents include 3,4-dimethyl-6-(2-methyl-1-propenyl)-1,2,3,6-tetrahydrophthalic anhydride, 1-isopropyl-4-methyl- Bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, hexahydrophthalic anhydride, methylhimic anhydride, pyromellitic acid Dianhydride, maleated alloocimene, benzophenonetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetrabisbenzophenonetetracarboxylic dianhydride, (3,4-dicarboxyphenyl) ether dianhydride , bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride and the like, and these may be used alone or in combination of two or more. It can be used in combination.

When an acid anhydride-based curing agent is used as the curing agent, the amount of the acid anhydride-based curing agent used is preferably 0.2 to 30 parts by mass based on 100 parts by mass of the cyanate ester compound. 0.5 to 20 parts by mass is more preferable, and 1.0 to 10 parts by mass is even more preferable. If the amount of the acid anhydride-based curing agent used is less than 0.2 parts by mass, unreacted cyanate ester compounds may remain, resulting in a decrease in glass transition temperature or a decrease in adhesion. On the other hand, if the amount of the acid anhydride-based curing agent used exceeds 30 parts by mass, the storage stability may be poor and the glass transition temperature of the cured product may be lowered.

From the viewpoint of moldability and reliability as a sealing material, the thermosetting resin composition preferably contains a thermosetting resin selected from epoxy resins, maleimide resins, and cyanate ester compounds, more preferably cyanate. containing an ester compound. In particular, it is preferable to use a cyanate ester compound together with a curing agent. In addition, these thermosetting resins may be used individually by 1 type, or 2 or more types may be used together.

An inorganic filler may be added to the thermosetting resin composition. The inorganic filler is used for the purpose of lowering the coefficient of linear expansion of the thermosetting resin composition. The type of inorganic filler is not particularly limited, and generally known ones can be used. Examples of inorganic fillers include silicas such as spherical silica, fused silica and crystalline silica; inorganic nitrides such as silicon nitride, aluminum nitride and boron nitride; alumina, glass fibers and glass particles; Silicas are preferable from the viewpoints of excellent reinforcement effect of the obtained cured product and suppression of warpage of the obtained cured product. These can be used individually by 1 type or in combination of 2 or more types.

The average particle size and shape of the inorganic filler are not particularly limited, but the average particle size is preferably 0.1 to 40 μm, more preferably 0.5 to 40 μm. In this specification, the average particle size is a value obtained as a mass average value D ₅₀ (or median diameter) in particle size distribution measurement by a laser beam diffraction method.

In addition, from the viewpoint of high fluidity of the thermosetting resin composition used in the present invention, an inorganic filler having a plurality of particle size ranges may be used in combination as the inorganic filler. It is preferable to use spherical silica having a fine region of 3 μm, a medium particle size region of 3 to 7 μm, and a coarse region of 10 to 40 μm. It is more preferably in the range of ~40 μm. In order to further increase the fluidity, it is preferable to use spherical silica having a larger average particle size.

The amount of the inorganic filler in the thermosetting resin composition is 100 parts by mass of the thermosetting resin, or 300 to 1,900 parts by mass with respect to the total 100 parts by mass of the thermosetting resin when a curing agent is added. It is preferably 400 to 1,800 parts by mass, particularly preferably 500 to 1,600 parts by mass.
Further, the content of the inorganic filler is preferably 70 to 95% by mass of the total thermosetting resin composition, more preferably 80 to 94.5% by mass, and 85 to 94% by mass. is more preferred.

In addition, for the purpose of improving the adhesion between thermosetting resins and their curing agents and inorganic fillers, and for improving the adhesion between inorganic fillers and substrates, silane coupling agents, titanate coupling agents, etc. A coupling agent may be added to the thermosetting resin composition, or an inorganic filler previously treated with a coupling agent may be added to the thermosetting resin composition. The surface treatment method of the inorganic filler with a coupling agent is not particularly limited and may be carried out according to a conventional method.

Coupling agents include, for example, epoxy-functional alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. , N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, amino-functional alkoxysilanes, γ-mercaptopropyltrimethoxysilane, etc. Mercapto-functional alkoxysilanes such as methoxysilane, amine-functional alkoxysilanes such as γ-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, and the like.

The amount of the coupling agent in the thermosetting resin composition is 0.1 to 25 parts with respect to 100 parts by mass of the thermosetting resin, or the total 100 parts by mass of the thermosetting resin when a curing agent is added. It is preferably 0.5 to 20 parts by mass. When the amount is 0.1 parts by mass or more, a sufficient adhesive effect to the substrate can be obtained, and when the amount is 25 parts by mass or less, the viscosity is extremely lowered and there is no possibility of causing voids.

Moreover, the thermosetting resin composition may contain a curing accelerator. The type of curing accelerator is not particularly limited, and generally known ones can be used. Examples of the curing accelerator include phosphorus such as triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine/triphenylborane, tetraphenylphosphine/tetraphenylborate, and the like. tertiary amine compounds such as triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo[5.4.0]undecene-7; 2-methylimidazole, 2-phenylimidazole, 2 - imidazole compounds such as phenyl-4-methylimidazole; peroxides, urea compounds, salicylic acid and the like can be used.

The amount of the curing accelerator in the thermosetting resin composition is preferably 0.2 parts by mass to 10 parts by mass, and 0.5 parts by mass to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. is more preferable.

The thermosetting resin composition can be blended with a flame retardant in order to enhance flame retardancy.

The type of flame retardant is not particularly limited, and generally known ones can be used. Examples of flame retardants include phosphazene compounds, silicone compounds (such as silicone rubber powder), zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, and antimony trioxide. These flame retardants may be used singly or in combination of two or more. The amount of the flame retardant compounded in the thermosetting resin composition is preferably 2 to 100 parts by mass, more preferably 3 to 50 parts by mass, per 100 parts by mass of the thermosetting resin composition.

The thermosetting resin composition may contain an ion trap material to prevent deterioration of reliability due to ion impurities.

The type of ion trap material is not particularly limited, and generally known materials can be used. As the ion trap material, for example, hydrotalcites, bismuth hydroxide compounds, rare earth oxides and the like can be used. These may be used singly or in combination of two or more. The content of the ion trap material in the thermosetting resin composition is preferably 0.5 to 25 parts by mass, more preferably 1.5 to 15 parts by mass, per 100 parts by mass of the thermosetting resin.

The thermosetting resin composition may contain a release agent. The type of release agent is not particularly limited, and generally known agents can be used. The mold release agent is added to improve mold releasability during molding. Examples of release agents include natural waxes such as carnauba wax and rice wax; and synthetic waxes such as acid waxes, polyethylene waxes and fatty acid esters. Carnauba wax is preferred from the viewpoint of releasability.

The content of the release agent in the thermosetting resin composition is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the thermosetting resin. If the blending amount is 0.05 parts by mass or more, there is no possibility that sufficient releasability will be obtained, or overload will occur during melt-kneading during production. There is no risk of poor seepage, poor adhesion, or the like.

The thermosetting resin composition may contain a coloring agent. Examples of the coloring agent include known coloring agents such as carbon black, organic dyes, organic pigments, titanium oxide and red iron oxide. When the thermosetting resin composition contains a cyanate ester compound, carbon black is preferable from the viewpoint of dispersibility.

The amount of the colorant compounded in the thermosetting resin composition is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the thermosetting resin. It is more preferable to have

The shape of the thermosetting resin composition may be any shape, and may be powder, granule, sheet or pellet. If the shape is sheet-like or pellet-like, voids are less likely to occur when the thermosetting resin is melted. In addition, if it is in the form of a sheet or a pellet, heat is easily conducted uniformly to the thermosetting resin during heating and melting.

[Method for producing thermosetting resin composition]
As a method for producing the thermosetting resin composition used in the present invention, conventionally known methods can be appropriately used. Examples of manufacturing methods include planetary mixers, hot rolls, kneaders, extruders, and the like. When the obtained thermosetting resin composition is solid, it may be pulverized into powder, or may be powdered and then tableted into tablets or granules. may be used to form a sheet. Pellets or sheets are preferable from the viewpoint of reducing voids during molding.

The thermosetting resin composition thus obtained preferably has a thickness of 0.1 to 10 mm, more preferably 0.2 to 5 mm, if it is in the form of a sheet. In the case of pellets, the diameter is preferably 10 to 100 mm, more preferably 20 to 80 mm, and the length is preferably 0.5 to 50 mm, preferably 1 to 40 mm. more preferred.

EXAMPLES The present invention will now be described more specifically with reference to examples and comparative examples. The invention is not limited to the following examples.

Examples 1-18 and Comparative Examples 1-6
[Production of thermosetting resin composition]
Thermosetting resin compositions 1 to 10 were obtained by mixing at the blending amounts (parts by mass) shown in Table 1. Details of each component are as follows.

シアネートエステル化合物２：ノボラック型シアネートエステル化合物（下記式（３）ＰＴ－３０：ロンザジャパン）

Cyanate ester compound Cyanate ester compound 1: BisE type cyanate ester compound (following formula (2) LECY: Lonza Japan)

Cyanate ester compound 2: novolak-type cyanate ester compound (the following formula (3) PT-30: Lonza Japan)

Epoxy resin Epoxy resin 1: Trisphenolmethane type epoxy resin (EPPN-501H: manufactured by Nippon Kayaku Co., Ltd.)
Epoxy resin 2: cresol novolac type epoxy resin (N-655-EXP-S: manufactured by DIC Corporation)

Curing agent Curing agent 1: Trisphenolmethane type phenolic resin (MEH-7500: manufactured by Meiwa Kasei Co., Ltd.)
Curing agent 2: phenol novolac resin (TD-2131: manufactured by DIC)

Curing accelerator Curing accelerator 1: imidazole compound (2PHZ-PW: manufactured by Shikoku Kasei Co., Ltd.)
Curing accelerator 2: Phosphorus compound (TPP: manufactured by Hokko Chemical Co., Ltd.)

Coupling agent γ-glycidoxypropyltrimethoxysilane (KBM403: manufactured by Shin-Etsu Chemical Co., Ltd.)
Flame retardant rubber particles: silicone rubber powder (KMP-600: manufactured by Shin-Etsu Chemical Co., Ltd.)
Inorganic filler Fused silica: Fused spherical silica with an average particle size of 14 μm (manufactured by Tatsumori Co., Ltd.)
Colorant Carbon black (manufactured by Mitsubishi Chemical Corporation)

Determination of glass transition temperature The cured product obtained by molding the thermosetting resin composition under the conditions described in Examples and Comparative Examples was processed into a test piece of 5 × 5 × 15 mm, and then subjected to the test. The piece was set in a thermal dilatometer TMA8140C (manufactured by Rigaku Corporation). The heating program was set to a heating rate of 5°C/min and a constant load of 19.6 mN was applied. The relationship between this dimensional change and temperature was plotted on a graph (an example of the graph is shown in FIG. 2). From the thus obtained graph of dimensional change and temperature, the glass transition temperature in Examples and Comparative Examples was determined by the method for determining the glass transition temperature described below.
As shown in FIG. 2, two arbitrary temperature points at which the tangent line of the dimensional change-temperature curve can be obtained below the temperature of the inflection point are T1 and T2, and any arbitrary temperature at which the same tangent line can be obtained above the temperature of the inflection point. The two temperature points were T1' and T2'. Dimensional changes at T1 and T2 are D1 and D2, respectively, a straight line connecting points (T1, D1) and points (T2, D2), and dimensional changes at T1′ and T2′ are D1′ and D2′, respectively. The intersection of a straight line connecting (T1', D1') and the point (T2', D2') was taken as the glass transition temperature (Tg).

Determination of average thermal expansion coefficient (CTE1) Thermomechanical analysis of the cured product of the thermosetting resin composition was performed under the same conditions as the above glass transition temperature measurement, and from the measurement results in the temperature range from 40 ° C to 80 ° C, the average heat An expansion coefficient (an average value of linear expansion coefficients) was calculated and defined as CTE1 of the thermosetting resin composition.
Similarly, the average coefficient of thermal expansion of the semiconductor element mounting board was calculated and set as CTE1 of the semiconductor element mounting board.

Comparison between the average thermal expansion coefficient of the semiconductor device mounting substrate and the average thermal expansion coefficient of the thermosetting resin From the average thermal expansion coefficient of the semiconductor device mounting substrate and the average thermal expansion coefficient of the thermosetting resin The difference between the average thermal expansion coefficient of the thermosetting resin and the average thermal expansion coefficient of the semiconductor element mounting board was calculated from the following formula and shown in Table 2.

Measurement of Viscosity The viscosity of the thermosetting resin composition prepared with the compounding amount (parts by mass) shown in Table 1 was measured with a rheometer (plate diameter 25 mm, measurement frequency 1 Hz) set at 175 ° C., and the measured values are shown. 2.

Measurement of gelation time The gelation time of the thermosetting resin composition prepared with the blending amount (parts by mass) shown in Table 1 was measured on a hot plate set at 175 ° C., and the measured values are shown in Table 2. Described.

Manufacture of semiconductor element mounting substrate A commercially available adhesive is applied to the four corners of a 20 mm square 200 μm thick semiconductor element, and 120 pieces are pasted on various substrates with a diameter of 300 mm and a thickness of 775 μm shown in Table 2, on which dummy bumps are formed. A semiconductor device mounting substrate was manufactured. The dummy bump diameter was 30 μm, the bump pitch was 60 μm, and a gap of 30 μm was formed between the element and the substrate.

Manufacture of Semiconductor Device The semiconductor element mounting substrate prepared above was sealed with the thermosetting resin composition shown in Table 1 using a compression molding machine (manufactured by Apic Yamada Co., Ltd.). Molding temperature and molding time were carried out under the conditions shown in Table 2. After sealing, it was cured at 180° C. for 1 hour to manufacture a semiconductor device.

Amount of warpage Place the manufactured semiconductor device on a laser three-dimensional measuring machine so that the thermosetting resin surface faces upward, measure the height displacement in the diagonal direction of each semiconductor device, and measure the maximum value and the measurement. The difference from the minimum value was taken as the amount of warpage. A positive value is used when the direction of warp is downward, and a negative value is used when the direction of warp is upward.

Appearance In the manufactured semiconductor device, ○ indicates that neither flow marks nor pinholes occurred, △ indicates that either pinholes or flow marks occurred on the surface, and those that both flow marks and pinholes occurred was described in Table 2 as x.

Temperature cycle test (TCT)
The manufactured semiconductor device was singulated using a dicing machine to have a size of 22 mm × 22 mm. A temperature cycle test was conducted with one cycle of °C/15 minutes. First, at cycle 0, an ultrasonic flaw detector (QUANTUM 350 manufactured by Sonics) was used to non-destructively confirm the delamination state inside the semiconductor element using a 75 MHz probe. Next, a similar inspection was performed after 1,000 cycles.
If the total peeled area is less than about 5% of the area of the semiconductor element, it is evaluated as "no peeling" as micro peeling, and if the peeled area is 5% or more, it is evaluated as "with peeling". counted the number. Table 2 shows the results.

1. Thermosetting resin composition3. Semiconductor device mounting board 31 . semiconductor device 32 . substrate

Claims (11)

A method for manufacturing a semiconductor device in which a substrate on which two or more semiconductor elements are mounted is molded and sealed with a thermosetting resin composition,
The thermosetting resin composition contains a cyanate ester compound having two or more cyanato groups in one molecule; a curing agent, and an inorganic filler, and the molding temperature at the time of molding sealing is the thermosetting A semiconductor device having a glass transition temperature of a cured product of a resin composition or lower, a molding temperature of 140° C. or higher during molding and sealing, and a molding method of either transfer molding or compression molding. manufacturing method. The average thermal expansion coefficient of the cured product of the thermosetting resin composition in a temperature range below the glass transition temperature is -20% or more and +10% or less of the average thermal expansion coefficient of the substrate in the same temperature range. A method of manufacturing the semiconductor device according to 1. 3. The method of manufacturing a semiconductor device according to claim 1, wherein the thermosetting resin composition has a melt viscosity at 175° C. of 0.1 to 100 Pa·s. 4. The method of manufacturing a semiconductor device according to claim 1, wherein the thermosetting resin composition has a gelling time of 10 to 180 seconds at 175.degree. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the uncured shape of the thermosetting resin composition is tablet-like, granular-like, or sheet-like. 6. The method of manufacturing a semiconductor device according to claim 1, wherein the thermosetting resin composition is in the form of a sheet with a thickness of 0.1 mm to 10 mm. The cyanate ester compound has the following formula (1)

(wherein R ¹ and R ² represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ³ represents a single bond or

Any one of the divalent groups represented by R ⁴ is a hydrogen atom or methyl and n is an integer of 0-10. )
The method for manufacturing a semiconductor device according to any one of claims 1 to 6, wherein the cyanate ester compound represented by 8. The method for manufacturing a semiconductor device according to claim 1, wherein the curing agent is one or more selected from amine curing agents, phenol curing agents, and aqueous curing agents. 9. The method of manufacturing a semiconductor device according to claim 1, wherein the content of the inorganic filler is 70 to 95 mass % of the entire resin composition. 10. The method of manufacturing a semiconductor device according to claim 1, further comprising a curing accelerator. 11. The method of manufacturing a semiconductor device according to claim 1, wherein the substrate is one of a silicon wafer, a ceramic substrate, and a substrate.

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