JP2002003641A - Calcium carbonate for sealing filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing filler capable of solving the abrasion of a kneading machine generated when kneading is performed with a resin and giving excellent sealing characteristics. SOLUTION: The calcium carbonate for sealing filler is characterized in that BET specific surface area by nitrogen adsorption process is 15m2/g or less, mean diameter is 1 to 70 μm, purity is 95% or higher and water content is 3.0% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to calcium carbonate for a sealing filler, and more particularly to calcium carbonate used as a sealing material for electronic parts and semiconductor elements.

[0002]

2. Description of the Related Art In recent years, with the remarkable development of the field of electronic engineering, conventional electronic components have been reduced in size and performance, and new electronic components and semiconductor devices have been actively developed. When these components and elements are mounted on a device, sealing with a polymer resin material or a ceramic material is performed to maintain the reliability of the components and elements. According to the ceramic material, highly reliable encapsulation is possible.
The production cost as a sealing material was high. Therefore, recently, sealing with a general-purpose and inexpensive polymer resin material has become common.

In the case of a polymer resin sealing material, a sealing filler is added to and mixed with a resin to improve the coefficient of thermal expansion and thermal conductivity of the sealing material. Conventionally, materials used as sealing fillers are alumina and silica. However, since these materials have high hardness, problems such as abrasion of a kneader during kneading with a resin have occurred. Therefore, these materials are given a certain shape (for example, spherical particles).
And other improvements were required.

[0004]

Means for Solving the Problems The present inventors have made intensive studies in view of the above problems and as a result have found that a specific calcium carbonate is used as a sealing filler instead of the conventional alumina or silica. Calcium carbonate has excellent thermal stability, is stable up to about 500 ° C. even in the air, has excellent electrical insulation and dielectric properties, and has a lower hardness than alumina and silica. As a result of repeated investigations based on these facts, the use of calcium carbonate as a filler for sealing can eliminate the problem of abrasion caused when using alumina or silica, and is inexpensive in terms of cost. They have found that they can be used as materials, and have completed the present invention.

That is, the present invention provides a calcium carbonate for a sealing filler as described below.
Item 1. BET specific surface area by nitrogen adsorption method is 15 m ² /
g, an average particle diameter of 1 to 70 μm, a purity of 95% or more, and a water content of 3.0% or less.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The sealing filler in the present invention is:
Mainly refers to the material to be filled into the resin for sealing electronic components.

[0007] BET specific surface area by nitrogen adsorption method of calcium carbonate as a sealing filler is not more than 15 m ² / g, and preferably is 1~12m ² / g, more preferably 2 to 10 m ² / g. When the BET specific surface area by the nitrogen adsorption method exceeds 15 m ² / g, the primary particles of calcium carbonate are undesirably too fine.

The average particle size of the calcium carbonate is 1 to 70.
μm, preferably 2 to 50 μm, more preferably 3 to 30 μm, particularly preferably 5 to 20 μm.
m. If the average particle size exceeds 70 μm, good sealing properties may not be exhibited when used as a sealing filler, which is not preferable. Here, the average particle size refers to a value obtained by a laser diffraction / scattering type particle size distribution measuring device.

The calcium carbonate has a purity of 95% or more, preferably 97 to 100%, and more preferably 98 to 100%. When the purity is less than 95%,
When used as a sealing filler, sufficient sealing characteristics may not be exhibited, which is not preferable. The term “purity” as used herein refers to a value determined based on the calcium carbonate purity test in the official standard of food additives.

The water content of the above calcium carbonate is 3.0% or less, preferably 0 to 1.5%, more preferably 0 to 1.0%. If the water content exceeds 3.0%, the resin may adversely affect the resin when mixed with the resin as a sealing filler, which is not preferable. Here, the water content refers to a value obtained by a moisture test method for chemical products according to JIS K 0068.

The method for producing the calcium carbonate is not particularly limited, but may be a method of pulverizing limestone (heavy calcium carbonate), or a method of calcining limestone and then reacting with water to obtain calcium hydroxide, followed by carbon dioxide gas. (Precipitable calcium carbonate) is preferred. Further, a method of producing calcium carbonate by reacting a sodium carbonate solution with a calcium chloride solution may be used. Also,
These calcium carbonates having different production methods can be used in combination.

The shape of the calcium carbonate particles may be granular, plate-like, columnar, needle-like or cubic, but particles having a granular or cubic shape are preferred from the viewpoint of flowability. Particles having a plate-like, columnar or needle-like shape are preferred from the viewpoint of improving the mechanical strength and the like of a resin composition obtained by mixing with a resin. Therefore, a resin composition having desired characteristics can be obtained by mixing and using particles having different shapes.

As the crystal form of the calcium carbonate, calcite, badderite, aragonite or amorphous is known, but is not particularly limited in the present invention.

[0014] The term "encapsulating resin" as used herein means epoxy resin, polyimide resin, polyurethane resin, phenol resin, furan resin, melamine resin, urea resin, guanamine resin, vinyl ester resin, unsaturated polyester resin, diallyl phthalate. Refers to thermosetting resin such as resin,
Among them, epoxy resins, polyimide resins, polyurethane resins, phenol resins, and furan resins are often used.
These resins are used alone or in combination of two or more.

The amount of the sealing filler (calcium carbonate) charged into the resin is preferably 100 to 900 parts by weight of the sealing filler with respect to 100 parts by weight of the resin. If the amount of the sealing filler is less than 100 parts by weight, it is difficult to improve the properties of the resin. On the other hand, if it exceeds 900 parts by weight, it becomes difficult for the resin to cover the sealing filler uniformly, and it is difficult to obtain a good sealing resin composition.

In producing the sealing resin composition, the surface treatment of the calcium carbonate particles using a surface treating agent can improve the compatibility with the resin. Examples of effective surface treatment agents include fatty acids, rosins, Teflon (registered trademark), silicones, modified silicones, and silane coupling agents. For example, fatty acids include, specifically, stearic acid, oleic acid, palmitic acid, etc., and silane coupling agents include vinyl silane, amino silane, epoxy silane, chloroalkyl silane, mercapto silane, methyl triethoxy silane, etc. Is mentioned. The coating amount of these surface treatment agents varies depending on the type of resin used, but preferably ranges from 0.01 to
The content is 10% by weight, more preferably 0.05 to 7% by weight, particularly preferably 0.5 to 5% by weight. If the ratio is out of this range, the surface treatment effect may not be exhibited, or the compatibility with the resin may be deteriorated, and it may be difficult to obtain desired viscosity characteristics and the like in the obtained resin composition, which is not preferable.

The surface treatment method is not particularly limited as long as the surface of the calcium carbonate particles can be coated with the surface treatment agent, and a known method can be used. For example, coating can be performed by preparing a slurry of calcium carbonate in advance, mixing a surface treatment agent with the slurry, and mixing and kneading. Alternatively, the calcium carbonate powder can be coated by directly spraying a liquefied surface treatment agent.

[0018]

By using the calcium carbonate of the present invention as a filler for a sealing resin, the problem of abrasion of a kneader, which has conventionally been a problem when producing a resin composition containing alumina or silica, can be solved. . In addition, the sealing resin composition containing the calcium carbonate of the present invention has a thermal conductivity, electrical insulation, dielectric properties, and a pressure cooker test that are equal to or better than the sealing resin composition containing alumina or silica. The above sealing characteristics are shown. Furthermore, the calcium carbonate of the present invention is a material that is less expensive than alumina and silica and is harmless to the environment and humans, and therefore the present invention is very useful in the field of electronic materials.

[0019]

The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention.

Example 1 A BET specific surface area measured by a nitrogen adsorption method was 5 m ² / g, and an average particle size measured by a laser diffraction scattering type particle size distribution analyzer was 15%.
The purity determined in accordance with the calcium carbonate purity test of the official standard of food additives was 98.0% in JIS K 006 μm.
The surface of a heavy calcium carbonate powder having a moisture content of 0.6% according to the moisture test method of Chemical Product No. 8 was treated with a silane coupling agent (epoxysilane) (coating amount: 1.0% by weight).

The surface-treated calcium carbonate (400 parts by weight) and epoxy resin (trade name “KMC” manufactured by Shin-Etsu Chemical Co., Ltd.)
-130 ") was sufficiently mixed with a kneader to obtain a resin composition. At that time, no abrasion of the kneader was observed. When the obtained resin composition was used as a sealing resin composition for a semiconductor element component, good sealing properties were exhibited.

Example 2 BE in a calcium hydroxide slurry was prepared by a nitrogen adsorption method.
Calcium carbonate powder having a T specific surface area of 10 m ² / g and an average particle size of 2 μm was added, and carbon dioxide was blown into the slurry to precipitate calcium carbonate. The obtained calcium carbonate is further added to a calcium hydroxide slurry,
Calcium carbonate was precipitated by the same operation. By repeating this operation, the BET specific surface area by the nitrogen adsorption method is 4 m ² / g, the average particle size by the laser diffraction scattering type particle size distribution measuring device is 10 μm, and it conforms to the official calcium carbonate purity test of food additives. Purity determined by the above.
At 0%, a calcium carbonate powder having a moisture content of 0.5% according to the moisture test method for chemical products according to JIS K 0068 was obtained. This powder was surface-treated using a silane coupling agent (methyltriethoxysilane) solution (coating amount: 1.5% by weight).

The obtained surface-treated calcium carbonate powder is
It was mixed with an epoxy resin in the same manner as in Example 1, and a reliability test was performed. As a result, good sealing characteristics were exhibited as the sealing resin composition, and no abrasion of the kneader during mixing was observed.

Comparative Example 1 The BET specific surface area was 1 m ² / g by the nitrogen adsorption method, and the average particle size was 15 by the laser diffraction scattering type particle size distribution analyzer.
0 μm, the purity determined according to the calcium carbonate purity test of the official standard of food additives is 98.0%, and JIS K00
The moisture content of the 68 chemical products according to the moisture test method is 0.5%
Was used in the same manner as in Example 1 to obtain a sealing resin composition, and its reliability test was performed. As a result, good sealing properties were not exhibited as a sealing material.

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Claims (1)

[Claims] 1. A BET specific surface area of 15 by a nitrogen adsorption method.
m ² / g or less, the average particle size is 1 to 70 μm, and the purity is 9
A calcium carbonate for a sealing filler, having a content of 5% or more and a water content of 3.0% or less.