JP2003138100A - Epoxy resin composition for flip chip mounting and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition for bonding and filling in flip-chip mounting for bonding a wiring board and a semiconductor element, and to provide a semiconductor device having good reliability against temperature change and humidity resistance. SOLUTION: An epoxy resin which is liquid at normal temperature, an organic-inorganic material having an average particle diameter of 1 to 6 μm and a thixotropic ratio obtained by heating and kneading with a spherical inorganic filler having a maximum particle diameter of 20 μm or less is less than 1.5. It contains a compound (A), a latent curing catalyst (B), and an adhesion promoter (C) as main components, and the adhesion promoter is in a range of 0.02 to 4 parts by weight based on 100 parts by weight of the epoxy resin. An epoxy resin composition for flip chip mounting, which is contained in the above. The flip chip semiconductor device 5 is formed by bonding the substrate 1 and the semiconductor element 4 with the epoxy resin composition 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for flip-chip mounting, and more particularly, to an epoxy resin composition for flip-chip mounting used when a semiconductor element is pressed against a substrate, and manufactured using the same. The present invention relates to a semiconductor device.

[0002]

2. Description of the Related Art Flip-chip mounting is one of the solutions to the demand for higher density mounting than the conventional chip-on-board which is a mounting method for electronic components. This flip-chip mounting includes a method of forming a metal bond in advance and then sealing with a resin (C4, SBB, etc.), and a collective bonding method with a resin (pressure welding method, etc.).

In particular, in the above method, since the construction method itself is simple, there is an advantage that the cost can be easily reduced. Further, unlike the case of the above-mentioned method, there is no need to reduce the viscosity of the resin, so that the range of resin design is widened. However, until now, there has been no epoxy resin composition that achieves both high reliability and good mountability,
The study as a low cost construction method has hardly progressed so far.

On the other hand, in order to improve the reliability characteristics of epoxy resin compositions used for sealing semiconductor devices, bonding semiconductor elements, etc., against temperature changes evaluated in a temperature cycle test, epoxy resin compositions have been used. Attempts have been made to reduce the linear expansion coefficient. And, in general,
A method of incorporating a spherical inorganic filler or the like into an epoxy resin is used. However, with this method alone, (1) the adhesiveness between the semiconductor element and the substrate is reduced, and problems such as peeling occur at the interface, and (2) at the interface between the epoxy resin and the spherical inorganic filler. Due to the lack of adhesion, the cured product had problems such as reduced mechanical strength and increased water absorption. Methods for solving both the problems (1) and (2) include a method using an additive (silane coupling material) (Japanese Patent Laid-Open No. 2001-187836) and the like. Due to the large amount of additive required, the water absorption rate increased, which often caused problems in the moisture resistance reliability test. On the other hand, as a method for improving the adhesion at the interface between the epoxy resin and the spherical inorganic filler, a method using an organic-inorganic hybrid compound (Japanese Patent Laid-Open No. 10-95901) has been proposed. However, there is a problem in that the adhesion strength to the semiconductor element or the substrate is insufficient only by the above. In addition, since this organic-inorganic hybrid compound is usually produced by a mechanical method called mechanochemical, there is a problem that the compounding amount of the spherical inorganic filler cannot be increased as compared with a general method due to manufacturing restrictions. There was also.

[0005]

SUMMARY OF THE INVENTION The object of the present invention was made in view of the above-mentioned circumstances, and moisture-proof adhesion without impairing the filling property between the semiconductor element and the substrate during flip-chip mounting, that is, the mountability. An object of the present invention is to provide a flip chip mounting epoxy resin composition having improved power and a semiconductor device using the same. Further, another object of the present invention is to
An object of the present invention is to provide an epoxy resin composition for flip chip mounting suitable for the above method.

[0006]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the present inventors have found that an epoxy resin composition for flip chip mounting (hereinafter sometimes simply referred to as a resin composition). In, the thixo ratio is less than 1.5 using an organic-inorganic blend, further found that the above problem can be solved by blending an appropriate amount of an adhesion promoter in the resin composition, to complete the present invention. I arrived.

That is, the present invention has the following main components:
Flip containing (A) ~ (C) component, the epoxy resin (E) 100 parts by weight, the adhesion promoter (B) is contained in the range of 0.02 to 4 parts by weight. It is an epoxy resin composition for chip mounting. (A) An epoxy resin (E) that is liquid at room temperature and a spherical inorganic filler (B) having an average particle size of 1 to 6 μm and a content of large particles having a particle size of 20 μm or more of 1% or less. An organic-inorganic compound (C) having a thixo ratio of less than 1.5 obtained by mixing (C) a latent curing catalyst (D) an adhesion promoter, wherein the total content of (D) component and (E) component is 80 ~ 98% by weight, and the mixing ratio (weight ratio) of component (E) and component (D) is 20.
It is one of the preferred embodiments that the content of the component (B) is 5 to 30 parts by weight with respect to 100 parts by weight of the component (E), and that the property is a paste. is there.

Further, the present invention is a method for manufacturing a semiconductor device in which a wiring board and a semiconductor element are bonded to each other via an epoxy resin composition, wherein the wiring board is partially coated with the flip-chip epoxy resin composition. Manufacturing a semiconductor device, characterized in that a semiconductor element having bumps is mounted on a portion coated with the resin composition, and the resin composition is cured at the same time as or after the conductor portion on the wiring board and the bumps of the semiconductor element are bonded. Is the way.

Further, the present invention is a flip chip semiconductor device in which a wiring board and a semiconductor element are bonded by the above flip chip mounting epoxy resin composition. Further, the present invention is a flip chip semiconductor device in which at least a part of a gap between a wiring board and a semiconductor element is filled with a cured product of the above flip chip epoxy resin composition.

The present invention will be described in detail below. The flip-chip mounting epoxy resin composition of the present invention is an organic resin obtained by mixing an epoxy resin (E) and a spherical inorganic filler (D).
Inorganic compound (A), latent curing catalyst (B) and adhesion promoter
Contains (C) as a main component. Therefore, the epoxy resin composition of the present invention contains the epoxy resin (E), the spherical inorganic filler (D), the latent curing catalyst (B) and the adhesion promoter (C) as main components. In the present specification,
(A) organic-inorganic blend, (B) latent curing catalyst, (C) adhesion promoter, (D) spherical inorganic filler and (E) epoxy resin, respectively (A) component, (B) component , (C) component, (D) component and (E) component. The resin composition is preferably in the form of paste, and the preferable viscosity range in this case is 80 to 5000 Pa · s (25 ° C.). Also, the thixo ratio is 1.5
It is also preferably less than. For use in the above method, the viscosity range is preferably several tens Pa · s or less.

As the epoxy resin (E), a liquid epoxy resin at room temperature (25 ° C.) is used. Specific examples of such epoxy resin include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, carboxylic acid glycidyl ester type epoxy resin, and phenol novolac type. Examples thereof include epoxy resin and urethane-modified bisphenol A type epoxy resin, and one or more of them can be used. When the epoxy resin is a mixture of two or more epoxy resins, it may be liquid at room temperature in the mixed state. here,
The liquid means a material having fluidity, and includes a material exhibiting poor crystallinity that does not sufficiently solidify (crystallize) at room temperature even if the melting point or the glass transition point is room temperature or higher. Further, the epoxy resin preferably has a hydrolyzable chlorine content of 600 ppm or less.

Examples of the type of the spherical inorganic filler (D) include, but are not limited to, oxides such as silica and alumina, silicates such as glass beads, and nitrides such as aluminum nitride and silicon nitride. Further, these may be used alone or in combination of two or more. The average particle size needs to be in the range of 1 to 6 μm. Further, the content of large particles having a maximum particle size of 20 μm or less or a particle size of 20 μm or more is required to be 1% or less. Preferably, the average particle size is 1 to 5
It is preferable that the particle size is μm and the maximum particle size is 15 μm or less. By satisfying this requirement, the filling property between the semiconductor element and the substrate, that is, the mountability can be improved. If the average particle size is less than 1 μm, it becomes difficult to highly fill the spherical inorganic filler when preparing the organic-inorganic mixture in advance, and if the average particle size exceeds 6 μm, the maximum particle size is 20 μm. The number of particles to be exceeded increases, and classification etc. is required. In addition, the particle size distribution on the coarse particle side is changed by an operation such as classification, which makes it difficult to achieve high packing when preparing an organic-inorganic compound. In addition, the organic-inorganic compound prepared with a spherical inorganic filler containing coarse particles having a maximum particle size of more than 20 μm causes scratches or disconnection of the wiring part of the semiconductor element during flip chip mounting, and causes a gap between the semiconductor element and the substrate. The electrical connection of may not be able to be established. The spherical shape in the spherical inorganic filler refers to, for example, a shape in which the inorganic filler is solidified in a rounded state due to surface tension when melted. In the present invention, among the spherical inorganic fillers, it is preferable to use spherical silica that satisfies the requirements for the average particle diameter and the maximum particle diameter.

In the present invention, (E) an epoxy resin and (D) a spherical inorganic filler are premixed, and an organic-inorganic consisting of an epoxy resin and a spherical inorganic filler having a thixo ratio of less than 1.5, preferably 0.9 to 1.1. A blend is prepared, and the component (B) and the component (C) are blended with this to obtain a resin composition.

The (A) organic-inorganic blend comprises a spherical inorganic filler and an epoxy resin which is liquid at room temperature, preferably a partial reaction product of the spherical inorganic filler and an epoxy resin which is liquid at room temperature. It contains. The organic-inorganic blend is preferably obtained by heating and stirring the spherical inorganic filler and an epoxy resin which is liquid at room temperature at 100 to 160 ° C. In the present invention, the thixotropic ratio, using a cone plate type rheometer, in a cone of 3 ° × 24 mm φ, 0.5 (x) rpm, 25 ° C., viscosity after 2 minutes, and 5.0 (y).
The viscosity was measured at 25 ° C for 2 minutes at rpm, and the former value is divided by the latter value. The thixo ratio is SVI (Str
uctural Viscosity Index) value is sometimes called. However, if you cannot measure at the above 5.0 rpm, x /
Any rotation speed may be selected as long as the ratio is y = 1/10.
By increasing the thixo value caused by the presence of fine particles contained in the spherical inorganic filler and setting the thixo ratio to be less than 1.5, the spherical inorganic filler can be highly filled.

The (B) latent curing catalyst used in the present invention is
It is effective in maintaining the stability of the epoxy resin composition and improving the mountability without impairing the workability in the sealing step. The latent curing catalyst according to the present invention has the property of rapidly functioning as an epoxy resin curing catalyst at a specific temperature or higher. Examples of the latent curing catalyst that can be used include a microcapsule type and an amine adduct type. In the present invention, a microcapsule type latent curing catalyst is preferably used from the viewpoint of mountability and stability. In addition, several types of latent curing catalysts may be used in combination as long as both reliability and curability are compatible with each other. The latent curing catalyst may be masterbatched in order to improve workability, etc., but the latent curing catalyst in the present invention refers to one that functions as an active ingredient therein.

The adhesion promoter (C) used in the present invention is
It is possible to improve the moisture-resistant adhesion between the resin composition and the semiconductor element or the wiring board, which is effective in improving the moisture-resistant reliability.
As the adhesion-imparting agent, specifically, a silane coupling agent having an amino group, an epoxy group, an imidazole group, or the like is used. Note that the adhesion-imparting agent may be mixed with other components in consideration of dispersibility and the like, but the adhesion-imparting agent in the present invention refers to one that functions as an active ingredient therein.

The epoxy resin composition of the present invention has the above-mentioned (A)
The main components are the component, the component (B) and the component (C). In other words, the components (B) to (E) are the main components. Where (E) component and (D)
The blending ratio (weight ratio) of the components is (E) / (D) = 20 / 80-50
/ 50, preferably 25/75 to 40/60. The component (D) is 30 wt% or more, preferably 35 to 70 w.
The content of the component (E) and the component (D) is preferably 80 to 98% by weight. The amount of the latent curing catalyst used as the component (B) varies depending on the mounting process, but if the amount is small, the curability deteriorates and problems such as long time required for flip-chip mounting occur. It is selected in the range of 5 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin in the composition. Component (C) is
0.02 to 4 relative to 100 parts by weight of the epoxy resin which is the component (E)
It is necessary to use in the range of parts by weight, and it is particularly preferable to use in the range of 0.1 to 2 parts by weight. If the amount of the component (C) used is less than 0.02 parts by weight, the moisture-resistant adhesive strength is not sufficiently expressed, and if it exceeds 4 parts by weight, the moisture resistance reliability decreases.
In addition, the storage stability of the epoxy resin composition rapidly deteriorates.

The epoxy resin composition of the present invention comprises, in addition to the components (B) and (C), a small amount of a surfactant, a colorant, a modifier, a curing accelerator, within a range that does not impair the effects of the present invention. Other additives such as fillers and resins can be blended, but it is preferable to keep it to 15% by weight or less. Also,
The component (A), in addition to the components (D) and (E), a small amount of a surfactant, a colorant, a modifier within a range that does not impair the effects of the present invention,
Other additives such as fillers and resins can be blended, but it is preferable to keep it to 15% by weight or less.
Furthermore, all of the spherical inorganic filler and the epoxy resin may not be the component (D) and the component (E) constituting the component (A), and some of them may be blended as an additive such as other fillers and resins. Good.

The semiconductor device of the present invention is manufactured using the above-mentioned epoxy resin composition for flip chips. As a preferable method for manufacturing a semiconductor device, a flip chip epoxy resin composition is applied to a part of a wiring board, a semiconductor element having bumps is mounted on the applied part, and a conductor portion on the wiring board and a bump of the semiconductor element are mounted. It is a manufacturing method in which the resin composition is cured at the same time as or after joining and. The above resin composition or a cured product thereof exists between the obtained semiconductor element and the wiring board, and both are bonded and at least a part of the gap between them is filled. It should be noted that the resin composition or its cured product does not exist between the electrically connected portions.

A preferred example of manufacturing a semiconductor device using the resin composition of the present invention will be described with reference to FIG. 1 showing an example of the manufacturing process. First, the epoxy resin composition 2 is applied to a part of the wiring board 1 by applying it with a dispenser 3 or the like (a), and the semiconductor element 4 having bumps is provided from the upper part of the resin composition application part (placement part). Mounting is performed by applying a pressure sufficient to bond the conductor portion on the wiring board and the bump of the semiconductor element (b) (c). Then, simultaneously with or after the bonding, the epoxy resin composition is cured to obtain the semiconductor device 5 in which the semiconductor element and the substrate are fixed via the resin.
(d). Generally, the semiconductor element side is heated so that the resin is heated during pressurization and curing.

[0021]

EXAMPLES The present invention will be described below with reference to examples. The raw materials used in Examples and Comparative Examples are shown below. Silica A: average particle size 1 μm, maximum particle size 7 μm Silica B: average particle size 5 μm, maximum particle size 10 μm Silica C: average particle size 3 μm, maximum particle size 12 μm Silica D: average particle size 6 μm, maximum particle size 30 μm Curing catalyst A: Amicure PN-23 (Ajinomoto Fine Techno) Curing catalyst B: Novacure HX-3921HP (Asahi Kasei Epoxy) active catalyst component 35% Adhesion enhancer: Imidazolesilane IA-100F (Japan Energy) active component 70%

The judgment criteria for each evaluation item are shown below. [Mountability] Curable, void-free, visually evaluate fillet shape ◎: Good for all items ○: Good for two items △: Good for one item ×: Poor for all items

[TCT] Temperature cycle test (-55 ° C to 1
Timing of connection failure at 25 ° C ○: More than 1000 cycles △: 500 to 1000 cycles ×: Less than 500 cycles [PCT] Moisture resistance test (121 ° C ・
Connection failure occurrence time at 2 atm) ○: More than 100 hours △: 50 to 100 hours ×: Less than 50 hours

Example 1 50 parts by weight of a bisphenol A type epoxy resin (liquid) having an epoxy equivalent of 170 g / eq (liquid) and 50 parts by weight of a bisphenol F type epoxy resin (liquid) having an epoxy equivalent of 160 g / eq were added to a spherical inorganic filler ( Average particle size 5μm, maximum particle size 10μm) 200
Parts by weight were added, and the mixture was stirred under heating at 150 ° C. until the thixo ratio became less than 1.5 to obtain an organic-inorganic blend. To this organic-inorganic mixture, imidazole silane IA-100F (adhesiveness imparting agent) was added to the epoxy resin in an amount of 0.5 parts by weight, and then the above curing catalyst A (latent curing catalyst). Was mixed and mixed to prepare an epoxy resin composition. Using the epoxy resin composition obtained, mountability, a temperature cycle test (T
CT) and humidity resistance test (PCT) were evaluated.

In the semiconductor device of the example, an epoxy resin composition was applied onto a wiring board by using a dispenser manufactured by Iwashita Engineering Co., Ltd., and then FCB-IIM manufactured by Matsushita Electric Industrial Co., Ltd.
The semiconductor element is pressed to the resin composition on the substrate using, and the wiring portion on the substrate and the bump of the semiconductor element are joined,
The resin composition was cured at the same time as the bonding to produce a flip-chip connected semiconductor device. The curing was advanced by heating (280 ° C.) from the semiconductor element side.

Examples 2 to 4 and Comparative Examples 1 to 3 Example 1 was repeated except that the composition of the epoxy resin composition was changed as shown in Table 1.

Table 1 shows the compounding composition of the epoxy resin composition and the evaluation result of the semiconductor device using the same.
In addition, in the composition, the numerical values are parts by weight.

[0028]

[Table 1]

[0029]

Since the epoxy resin composition of the present invention uses the organic-inorganic compound having a specific thixo ratio, it is possible to increase the filling amount of the spherical inorganic filler, which results in moisture resistance and It is effective in developing heat resistance or low thermal expansion. Further, it has excellent mountability and is used for manufacturing a semiconductor device in flip-chip mounting in which a wiring board and a semiconductor element are bonded to each other. In particular, it is suitable for a pressure welding method in which bonding is performed at once through a resin. A semiconductor device manufactured using this has excellent moisture-resistant adhesive strength of the resin and good reliability against temperature changes and moisture resistance, and its industrial value is extremely high.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a semiconductor device.

[Explanation of symbols]

1 substrate 2 Epoxy resin composition 3 dispensers 4 Semiconductor element 5 Semiconductor device

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Claims (5)

[Claims] 1. An adhesiveness-imparting agent containing the following components (A) to (C) as main components and 100 parts by weight of an epoxy resin (E).
An epoxy resin composition for flip-chip mounting, comprising (C) in an amount of 0.02 to 4 parts by weight. (A) An epoxy resin (E) which is liquid at room temperature, and a spherical inorganic filler (D) having an average particle size of 1 to 6 μm and a content of large particles having a particle size of 20 μm or more of 1% or less. Organic-inorganic compound with mixed thixo ratio less than 1.5 (B) Latent curing catalyst (C) Adhesion enhancer 2. The total content of the epoxy resin (E) and the spherical inorganic filler (D) is 80 to 98% by weight, and the epoxy resin (E)
The compounding ratio (weight ratio) of the component and the spherical inorganic filler (D) is 20 to 5
The flip according to claim 1, which is 0:80 to 50, the compounding amount of the latent curing catalyst (B) is 5 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin (E), and the property is a paste. Epoxy resin composition for chip mounting. 3. A flip chip semiconductor device in which a wiring board and a semiconductor element are bonded by the epoxy resin composition for flip chip mounting according to claim 1. 4. A method for manufacturing a semiconductor device, which comprises bonding a wiring board and a semiconductor element via an epoxy resin composition, wherein the epoxy resin composition for flip-chip mounting according to claim 1 or 2 is provided on a part of the wiring board. A semiconductor device characterized in that the resin composition is applied and a semiconductor element having bumps is mounted on the resin composition application portion, and the resin composition is cured at the same time as or after the conductor portion on the wiring board and the bump of the semiconductor element are bonded. Manufacturing method. 5. A flip-chip semiconductor device, wherein at least a part of a gap between a wiring board and a semiconductor element is filled with a cured product of the epoxy resin composition for flip-chip mounting according to claim 1. .