JP2009274336A - Manufacturing method of resin composition for encapsulating semiconductor element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a resin composition for encapsulating a semiconductor element having a process of feeding a mixture from a feeding vessel such as a hopper, a ribbon mixer or the like to a melting and kneading machine to melt and knead the same, the method capable of preventing stagnation of a component in the feeding vessel without being affected by a shape or a volume of the feeding vessel thereby to manufacture the resin composition for encapsulating the semiconductor element having a stable physical property. <P>SOLUTION: The manufacturing method of the resin composition for encapsulating the semiconductor element containing components of an epoxy resin (A), a curing agent (B) and an inorganic filler (C) comprises a process of preparing a mixture of the component (A), the component (B) and the component (C), the average particle diameter of each component being adjusted to be 5 to 50 μm, a process of storing the mixture in the vessel for feeding the mixture to the melting and kneading machine, a process of feeding the stored mixture from the vessel to the melting and kneading machine to make the molten kneaded mixture, and a process of cooling and solidifying the molten kneaded mixture, and then pulverizing the solidified mixture. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a resin composition for encapsulating a semiconductor element used for encapsulating a semiconductor element.

Conventionally, semiconductor elements such as transistors, ICs, and LSIs are sealed with a resin composition containing an epoxy resin, a curing agent, an inorganic filler, and the like. In general, in the production of a solid resin composition for encapsulating a semiconductor element, a process of mixing and melting and kneading compounding components, and then pulverizing a product that has been rolled and cooled and solidified (Patent Document 1). ~ 3).
JP 2007-77333 A JP 2006-297701 A JP 2001-64398 A

  In the production process of these resin compositions, in order to increase production efficiency, a large amount of a mixture of compounding ingredients is prepared in advance and continuously melt-kneaded while being supplied to a melt-kneader. For example, it comprises a melt kneader 1 having the heater 3, rotor blades 4 and mixing chamber 5 shown in FIG. 1, and a hopper 2 which is a container (hereinafter referred to as a supply container) for supplying the mixture to the melt kneader 1. When a melt-kneading apparatus is used, a large amount of the mixture is temporarily stored in the hopper 2 and supplied from the hopper 2 to the melt-kneader 1 for continuous melt-kneading.

  However, while the mixture is being supplied from the hopper 2 to the melt kneader 1, a part of the components segregates in the hopper 2, and as a result, the composition of the resin composition obtained in the early and late stages of the melt kneading. There was a problem that the physical properties of the resin composition changed due to a slight change in the ratio. It is estimated that this is because part of the components stays on the wall surface of the hopper 2. For this reason, there is a possibility that it can be improved by changing the shape of the hopper 2. However, since the shape of the hopper 2 that has been conventionally used is wide-ranging, changing the manufacturing conditions for each shape has a problem in terms of manufacturing efficiency. is there.

  The segregation of a part of the components can occur not only when a melt kneader having a hopper is used as a supply container, but also when melt kneaded using a ribbon mixer or the like as a supply container.

  The present invention has been made in view of such circumstances. A resin composition for encapsulating a semiconductor element comprising a step of supplying a mixture from a supply container such as a hopper or a ribbon mixer to a melt kneader and melt-kneading the mixture. In production, the retention of components in the supply container can be prevented without being affected by the shape and capacity of the supply container, and as a result, fluctuations in the composition ratio due to segregation of some of the components are suppressed, and physical properties An object of the present invention is to provide a method for producing a resin composition for encapsulating a semiconductor element that is stable.

In order to solve the above problem, the present invention is a method for producing a resin composition for encapsulating a semiconductor element comprising the following components (A) to (C):
A step of obtaining a mixture of the component (A) and the component (B) adjusted so that the average particle diameter is 5 μm or more and 50 μm or less, and the component (C);
Storing the mixture in a container for feeding to a melt kneader;
Supplying the stored mixture from the container to a melt-kneader to obtain a melt-kneaded product,
A step of cooling and solidifying the melt-kneaded product,
It is characterized by including.
(A) Epoxy resin (B) Curing agent (C) Inorganic filler Furthermore, in the present invention, spherical conversion in the average particle diameter represented by the following formula (1) of the component (A) and the component (B). It is preferable that the weight is 0.4 to 20 times the spherical equivalent weight of the average particle diameter represented by the following formula (1) of the component (C).

  According to the present invention, when an epoxy resin (component A) and a curing agent (component B) adjusted to have an average particle size of 5 μm or more and 50 μm or less are used, an epoxy resin (component A), a curing agent (component B) When the mixture of inorganic filler (component C) is supplied from a supply container such as a hopper or ribbon mixer to a melt kneader, the retention of the components in the supply container affects the shape and capacity of the supply container. Can be prevented without being. As a result, it is possible to obtain a resin composition for encapsulating a semiconductor element that suppresses segregation of components and has stable physical properties.

  Next, embodiments of the present invention will be described in detail.

The manufacturing method of the resin composition for semiconductor element sealing of this invention contains the following (A)-(C) component.
(A) Epoxy resin (B) Curing agent (C) Inorganic filler In the method for producing a resin composition for sealing a semiconductor element of the present invention, an epoxy resin (component A) having an average particle size adjusted to 5 μm or more and 50 μm or less ) And a curing agent (component B). The epoxy resin (component A) and the curing agent (component B) prepared to have a predetermined average particle diameter may be obtained by pulverizing to a predetermined average particle diameter, as described later, You may use the commercial item adjusted so that it might become the average particle diameter of this.

  When the average particle diameter of the epoxy resin (A component) and the curing agent (B component) exceeds 50 μm, a mixture of the epoxy resin (A component), the curing agent (B component) and the inorganic filler (C component) is supplied. Segregation is likely to occur due to a part of the components staying in the supply container when being fed to the melt-kneader, and in particular, the content of the inorganic filler (component C) in the resin composition in the latter stage of kneading. Tend to be higher. In addition, epoxy resins (component A) and curing agents (component B) having an average particle size of less than 5 μm are generally difficult to obtain and are not practical.

  In order to more effectively suppress the segregation of components, it is preferable to use an epoxy resin (component A) and a curing agent (component B) adjusted so that the average particle size is 15 μm or more and 25 μm or less.

  The average particle size of the epoxy resin (component A), curing agent (component B), and inorganic filler (component C) was determined by using a laser diffraction / scattering particle size distribution measuring device for a sample arbitrarily extracted from the population. Measured.

  In the present invention, the weight in terms of sphere in the average particle size represented by the following formula (1) of the epoxy resin (A component) and the curing agent (B component) prepared to a predetermined average particle size is: The inorganic filler (component C) is preferably 0.4 to 20 times the spherical equivalent weight of the average particle diameter represented by the following formula (1). When it exceeds 20 times, a supply container is used when a mixture of an epoxy resin (component A), a curing agent (component B) and an inorganic filler (component C) is continuously supplied from the supply container to the melt kneader. This is because segregation of components due to retention of the mixture is likely to occur, and in particular, there is a tendency that the content of the inorganic filler (C component) in the resin composition in the latter stage of kneading is increased. Moreover, even if less than 0.4 times, the tendency for the segregation of a component to be seen is seen.

In addition, when the epoxy resin (component A) and the curing agent (component B) are pulverized so as to have a predetermined average particle diameter, from the viewpoint of easily obtaining a desired particle diameter, as a pulverizer, For example, a turbo mill or the like can be used. In that case, you may grind | pulverize an epoxy resin (A component) and a hardening | curing agent (B component) separately so that an average particle diameter may be 5 micrometers or more and 50 micrometers or less, or an epoxy resin (A component) and hardening | curing agent ( B component) may be pulverized so as to have an average particle size of 5 μm or more and 50 μm or less after mixing at a predetermined ratio. Furthermore, after mixing the inorganic filler (C component) in a predetermined ratio with the epoxy resin (A component) and the curing agent (B component) in advance, the average particle size may be pulverized to 5 μm or more and 50 μm or less. However, from the viewpoint of easily confirming the average particle diameter and specific gravity of the epoxy resin (component A) and the curing agent (component B), it is preferable to grind before mixing with the inorganic filler (component C).

  In addition, in the manufacturing method of the resin composition for sealing a semiconductor element of the present invention, in addition to the epoxy resin (component A), the curing agent (component B), and the inorganic filler (component C), a curing accelerator described later, Various additives added as necessary, such as flame retardants, pigments including carbon black, and the like can be used.

  These various additives may be added when the epoxy resin (component A) and the curing agent (component B) are pulverized, or the epoxy resin (component A), the curing agent (component B) and the inorganic filler (C You may add at the time of mixing of a component. Mixing can be performed using, for example, a Redige mixer or a Henschel mixer as a mixer.

  Subsequently, the mixture of the epoxy resin (component A) and the curing agent (component B) adjusted to have a predetermined average particle diameter and the inorganic filler (component C) is put into a supply container and melt-kneaded. Store.

  The supply container used in the method for producing a resin composition for encapsulating a semiconductor element of the present invention is not particularly limited. For example, a container having a storage function and a supply function such as a hopper and a ribbon mixer can be used. It does not depend on its capacity. Further, a plurality of supply containers may be connected and used. For example, a container in which the discharge port of the ribbon mixer is connected to the input port of the hopper can also be used.

  Then, the mixture is supplied from the supply container to the melt-kneader according to the capacity of the melt-kneader, and continuously melt-kneaded at 60 to 160 ° C. FIG. 1 shows a schematic configuration diagram of the melt-kneading apparatus used. That is, in this melt-kneading apparatus, the melt-kneader 1 is provided with a hopper 2 as a supply container, and the melt-kneader 1 is provided with a mixing chamber 5 provided with a heater 3 and rotor blades 4. And the mixture thrown into the hopper 2 is supplied to the one end part of the melt kneader 1 from the hopper 2, and the kneaded material is discharged | emitted from the other end part.

  Finally, the obtained kneaded product is cooled and solidified, and the solidified kneaded product is pulverized to 10 to 2000 μm to obtain a semiconductor element sealing resin composition.

  It does not specifically limit as an epoxy resin component (A component) used in the manufacturing method of the resin composition for semiconductor element sealing of this invention. For example, various epoxy resins such as a dicyclopentadiene type epoxy resin, a cresol novolak type epoxy resin, a phenol novolak type epoxy resin, a bisphenol type epoxy resin, a biphenyl type epoxy resin, and a trishydroxyphenylmethane type epoxy resin can be used. These epoxy resins may be used alone or in combination of two or more. As such an epoxy resin, from the viewpoint of ensuring toughness after curing of the epoxy resin and reactivity of the epoxy resin, an epoxy equivalent of 150 to 250, a softening point or a solid at a normal temperature of 50 to 130 ° C. is preferable. Among them, from the viewpoint of reliability, a cresol novolac type epoxy resin, a biphenyl type epoxy resin, and a low moisture absorption type epoxy resin in which a lower alkyl group is added to the phenyl ring can be suitably used.

  The curing agent (component B) is not particularly limited as long as it causes a curing reaction with the epoxy resin (component A). For example, acid anhydrides, phenol resins, amines, thiols, etc. Among them, it is preferable to use a phenol resin in terms of excellent storage stability, curability, and physical properties of the cured product. As the phenol resin, for example, dicyclopentadiene type phenol resin, phenol novolac resin, cresol novolac resin, phenol aralkyl resin, or the like is used. These phenolic resins may be used alone or in combination of two or more. And as a phenol resin, it is preferable to use a hydroxyl equivalent of 70-250 and a softening point of 50-110 degreeC from a reactive viewpoint with an epoxy resin (A component). From the viewpoint, a phenol novolac resin can be preferably used. From the viewpoint of reliability, low hygroscopic materials such as phenol aralkyl resins and biphenyl aralkyl resins can also be suitably used.

  And the compounding ratio of an epoxy resin (A component) and a phenol resin (B component) is a phenol resin (B component) with respect to 1 equivalent of epoxy groups in an epoxy resin (A component) from a viewpoint of hardening reactivity. It is preferable to mix | blend so that the sum total of the hydroxyl group may be 0.5-2.0 equivalent, More preferably, it is 0.7-1.5 equivalent.

  The inorganic filler (component C) is not particularly limited, and various conventionally known fillers can be used. Examples thereof include powders of quartz glass, talc, silica (such as fused silica and crystalline silica), alumina, aluminum nitride, and silicon nitride. These may be used alone or in combination of two or more. Among them, it is preferable to use silica powder from the viewpoint that the thermal expansion coefficient of the obtained cured body can be reduced and internal stress can be reduced, so that warpage between the substrate and the element after resin sealing can be suppressed. It is more preferable to use fused silica powder from the viewpoints of high filling properties and high fluidity.

  The inorganic filler (component C) is preferably one having an average particle size in the range of 0.5 to 45 μm, more preferably in the range of 5 to 35 μm from the viewpoint of more effectively preventing segregation of the components. More preferably, it is used.

  The content of the inorganic filler (component C) is preferably set in the range of 50 to 90% by weight of the entire semiconductor element sealing resin composition. Particularly preferred is 60 to 90% by weight. That is, if it is less than 50% by weight, the linear expansion coefficient of the cured product is increased, the stress on the semiconductor element to be sealed is increased, and the function is liable to be deteriorated or cracked due to temperature change. Moreover, it is because the viscosity of an epoxy resin composition will become high and the tendency for a moldability to fall will be seen when it exceeds 90 weight%.

  In addition, in the manufacturing method of the resin composition for semiconductor element sealing of this invention, as mentioned above other than an epoxy resin (A component), a hardening | curing agent (B component), and an inorganic filler (C component), it is required. Accordingly, other additives such as a curing accelerator, a flame retardant, a release agent, and a pigment such as carbon black can be appropriately blended.

  The curing accelerator is not particularly limited as long as it accelerates the curing reaction between the epoxy resin (component A) and the curing agent (component B), and various conventionally known curing accelerators can be used. . For example, a phosphorus hardening accelerator, an amine hardening accelerator, a diazabicycloalkene hardening accelerator, etc. are mention | raise | lifted.

  Examples of the flame retardant include organic phosphorus compounds, antimony oxide, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, and the like. These may be used alone or in combination of two or more.

  The method for sealing a semiconductor element using the resin composition for sealing a semiconductor element obtained by the method for manufacturing a resin composition for sealing a semiconductor element of the present invention is not particularly limited. It can be performed by a known molding method. Moreover, the resin composition for encapsulating a semiconductor element may be used in a powder form as it is, or may be used after being molded into a tablet.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

First, each component shown below was prepared.
[Epoxy resin a]
Biphenyl type epoxy resin (epoxy equivalent 190, melting point 105 ° C)
[Epoxy resin b]
Cresol novolac type epoxy resin (epoxy equivalent 195, melting point 75 ° C.)
[Curing agent]
Phenol novolac resin (hydroxyl equivalent 110, softening point 100 ° C)
[Inorganic filler a]
Crushed fused silica powder with an average particle size of 8 μm [inorganic filler b]
Crushed fused silica powder with an average particle size of 10 μm [inorganic filler c]
Spherical fused silica powder with an average particle size of 15 μm [inorganic filler d]
Spherical fused silica powder with an average particle size of 30 μm [inorganic filler e]
Crushed fused silica powder with an average particle size of 15 μm [curing accelerator]
Triphenylphosphine (release agent)
Carnauba wax (silane coupling agent)
γ-Glycidoxypropyltrimethoxysilane (pigment)
Carbon black (flame retardant)
Antimony trioxide [Examples 1-5, Comparative Examples 1-5]
In Table 1, the composition of the resin composition I and II for semiconductor element sealing produced in Examples 1-5 and Comparative Examples 1-5 was shown. After mixing an epoxy resin (component A) and a curing agent (component B) in the composition shown in Table 1, Examples 1-5 are turbo mills and Comparative Examples 1-5 are appropriately used as a pulverizer using a hammer mill. By changing and pulverizing, an adjusted product of an epoxy resin (component A) and a curing agent (component B) having the average particle sizes shown in Tables 2 and 3 was obtained.

  And the Henschel mixer (capacity: 200L) as a mixer so that the total amount of the adjusted components, the inorganic filler (component C) and the other additives shown in Table 1 are 100 kg in the proportions shown in Table 1. Was mixed by dispersion for 2 minutes to obtain a mixture.

  In addition, the average particle diameter of a preparation and an inorganic filler (C component) is by measuring the particle size distribution of each component with a wet method using the laser diffraction / scattering type particle size distribution measuring apparatus LA-910 made by HORIBA. Calculated.

  Subsequently, the mixture was put into a hopper (capacity: 400 L) which is a supply container provided in the melt-kneading apparatus. This process was repeated twice so that the mixture in the hopper totaled 200 kg.

The mixture in the hopper was melt-kneaded (temperature: 80 ° C.) while being continuously supplied from the hopper to the screw-type melt kneader at a flow rate of 200 kg / hour. The kneaded material discharged from the screw melt kneader was sampled 6 times at intervals of 3 minutes from the start of discharge, then once after 20 minutes, and further 7 times at intervals of 3 minutes. Each kneaded material collected at each time is rolled with a calender roll to be air-cooled and solidified, and each air-cooled and solidified kneaded material is pulverized using a hammer type pulverizer, and each of Examples 1 to 5 and Comparative Examples 1 to 5 is crushed. A resin composition was obtained.
[Resin Composition Evaluation Method 1]
Transfer molding (heating condition: 175) was performed by press-molding a tablet having a diameter of 30 mm with 30 g of each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 to 5 obtained by the above method and preheating to 80 ° C. After heat curing at [° C. × 2 minutes], a test piece for specific gravity measurement was obtained by post-curing at 175 ° C. × 5 hours, and the specific gravity was measured. And the fluctuation range of specific gravity was computed. The specific gravity measurement method conformed to JIS-K6911.
[Resin Composition Evaluation Method 2]
Further, using each resin composition obtained by the above method, a spiral flow measurement at 175 ° C. was performed according to ASTM D3123-98 (2004). Then, the fluctuation range of the spiral flow length was calculated.

As a result, as shown in Table 2 and Table 3, the example product in which the average particle diameter of the adjusted product is 5 μm or more and 50 μm or less is compared with the comparative product in which the average particle size of the adjusted product exceeds 50 μm. Variations in the specific gravity and spiral flow length of the resin composition were suppressed. That is, in the method for producing a resin composition for encapsulating a semiconductor element of the present invention, when the mixture is continuously melt-kneaded, the change in physical properties of the resin composition is small and stable in the initial and later stages of melt-kneading. be able to.

It is a block diagram of the melt-kneading apparatus used suitably for the manufacturing method of the resin composition for semiconductor element sealing of this invention.

Explanation of symbols

1 Melting and kneading machine 2 Hopper 3 Heater 4 Rotor blade 5 Mixing chamber

Claims (2)

It is a manufacturing method of the resin composition for semiconductor element sealing containing the following (A)-(C) component,
A step of obtaining a mixture of the component (A) and the component (B) adjusted so that the average particle diameter is 5 μm or more and 50 μm or less, and the component (C);
Storing the mixture in a container for feeding to a melt kneader;
Supplying the stored mixture from the container to a melt-kneader to obtain a melt-kneaded product,
A step of cooling and solidifying the melt-kneaded product,
The manufacturing method of the resin composition for semiconductor element sealing characterized by including this.
(A) Epoxy resin (B) Curing agent (C) Inorganic filler The weight in terms of sphere in the average particle size represented by the following formula (1) of the component (A) and the component (B) is the average particle size represented by the following formula (1) of the component (C). It is 0.4-20 times with respect to the weight of spherical conversion, The manufacturing method of the resin composition for semiconductor element sealing of Claim 1 characterized by the above-mentioned.