JPH0473804A - Tray for integrated circuit - Google Patents

Abstract

PURPOSE:To improve colorability and maintain necessary conductivity by using a mixture of a specific ratio of carbon fibers to a current carrying material coating titanium oxide as a conductive filler. CONSTITUTION:A tray for IC consists of a resin molding material having basic blending, in which 100 to 150 pts.wt. of a mixture having wt ratio of 5/5 to 8/2 of carbon fibers and current-carrying coating titanium oxide is added to a resin matrix of 100 pts.wt. of a mixture of diallyl phthalate resin and unsaturated polyester resin while having surface electric resistance of 10<3> to 10<8>OMEGA glass transition temperature not less than 150 deg.C and water absorption not exceeding 0.45%. Thereby, the tray for IC can be uniformly colored into optional colors excepting black by jointly using appropriate pigments while enabling the tray surface to be furnished with desired conductivity to be maintained for a long term.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a tray for integrated circuits (hereinafter abbreviated as IC), and more specifically, it relates to a tray for integrated circuits (hereinafter abbreviated as IC), and more specifically, a tray that has a low water absorption rate, a low surface electrical resistance (and has a long shelf life). The present invention relates to a non-black IC tray that can be used for baking at temperatures of 150° C. or higher, and that can facilitate product variety management in IC production by color classification.

[Conventional technology]

BACKGROUND ART Conventionally, surface mounting has progressed in the field of IC mounting, and IC feeding by trays has become common. That is,
In order to prevent heat cracks (puff cage cracks) caused by solder heat when mounting an IC on a printed circuit board, the IC is For example, a plate-shaped tray is used in which a large number of product accommodating portions each having a concave groove portion are formed.

Recently, as the degree of IC integration has increased, package cracks have frequently occurred during surface mounting, and for this reason, heat curing of ICs at high temperatures of 150° C. or higher has become commonplace. As an IC tray that can be put to practical use under such conditions, the applicant has previously disclosed a tray made of a thermosetting resin-carbon black composition that has excellent heat resistance, impact resistance, and long-term storage stability. (Specification of Japanese Patent Application No. 63-315071).

[Problem to be solved by the invention]

However, due to the diversification of ICs, it has become difficult to manage product types using only conventional carbon black formulations, and by changing the color of trays for each product on the production line side, production management can be done more efficiently. It is hoped that this will be done.

Therefore, the following methods have been investigated using various resins in order to arbitrarily produce products with a wide variety of colors, but each method has had its own technical problems.

(1) A method of increasing colorability by blending titanium oxide and pigments in addition to conventional carbon-based fillers. In this case, it is necessary to mix 15 parts or more of carbon black in order to maintain the necessary conductivity, and therefore 200 parts or more of titanium oxide is required to whiten the tray. As a result, the resin fraction becomes low, making it unsuitable as a molding material.

(2) A method of blending metal powder such as iron and pigment as a non-black filler. After forming the tray, the surface of the mixed metal powder becomes oxidized over time, increasing the surface resistance of the tray and making it unusable.

(3) A method of blending metal-coated mica filler such as nickel and fiber as a non-black conductive filler. Although it has coloring properties, since the filler shape is large, it is necessary to mix 150 parts or more to 100 parts of resin to maintain the necessary conductivity, and as a result, the surface of the molded product tends to become rough and has a poor appearance. becomes. Furthermore, air oxidation of the metal coating increases surface resistance and leads to insulation, making it unsuitable for use.

(4) A method of applying conductive paint to a conventional black conductive tray. In this case, since the paint is required to have heat resistance, the types of colors are often limited, and it is also unsuitable because the paint film peels off during baking and contaminates the surrounding area.

[Means to solve the problem]

The present invention has been completed by discovering that the above-mentioned problem can be solved by using a mixture of carbon fiber and current-carrying material coating titanium oxide in a specific ratio as a conductive filler.

That is, the present invention provides a resin matrix containing 100 parts by weight of a mixture of diallyl phthalate resin and unsaturated polyester resin, and 100 parts by weight of a mixture of carbon fiber and titanium oxide coated with an electrically conductive material in a weight ratio of 515 to 8/2.
The tray for integrated circuits is made of a resin molding material having a basic composition of 150 parts by weight, and has a surface electrical resistance of 103 to 108 Ω, a glass transition temperature of 150°C or more, and a water absorption rate of 0.45% or less.

In the present invention, in order to maintain heat resistance, a diallyl phthalate resin and an unsaturated polyester resin with low water absorption are used as a matrix. Diaryl phthalate resin and unsaturated polyester resin use a radical addition polymerization reaction system, so there is no generation of reaction water, hydrogen sulfide, amine gas, etc. that corrode the metals used in ICs during the reaction process. Therefore, it is suitable. In addition, the glass transition temperature is 15
It is also preferable that the temperature is 0°C or higher.

A mixture of these resins is used because diallyl phthalate resin alone has poor kneading properties and cannot form a molding material, and unsaturated polyester resin alone results in a tray molded product having a water absorption rate of 0.45% or more. This is because by using a mixture of these, kneading is possible and the water absorption rate of the tray molded product can be made 0.45% or less. In addition, one of the reasons why it is preferable is that the shrinkage rate of the molded article can be controlled by adjusting the mixing ratio of these resins. A preferred mixing ratio is a diallylphthalate/unsaturated polyester ratio of 2/8 to 8/2, particularly 4/6 to 6/4.

In addition, considering heat resistance, diallyl phthalate resin is suitable for diallyl phthalate resin, and hydrogenated bisphenol-based unsaturated polyester resin, which has low water absorption and heat resistance of 150°C or higher, is suitable for unsaturated polyester resin. ing.

Graphite grade carbon fiber is suitable for the carbon fiber used in the present invention in terms of water absorption.
Carbon grade carbon fiber has a water absorption rate of nearly 10% (which is undesirable because it promotes an increase in the water absorption rate of the entire tray. Also, if the carbon fiber is less than 1 mm, it is too small, so a large amount of carbon fiber is used to increase conductivity. Since it requires blending, the phenomenon of blackening of the appearance occurs.Therefore, the optimum material is carbon fiber with an average diameter of 1 to 20 mm and an average length of 0.1 to 1.0 mm.

The current-carrying material-coated titanium oxide used in combination with carbon fiber in the present invention is obtained by coating the surface of highly white titanium oxide with a current-carrying material to form a minute white current-carrying filler. Due to its particle structure, this titanium oxide coating as a conductive material works together with carbon fibers to impart desired conductivity, colorability, and moldability to the tray. Although its mechanism of action has not been fully elucidated, in the tray of the present invention, as shown in FIG. While compounding, a structure is formed in which the carbon fibers are connected with the micro conductive filler 3 made of titanium oxide coated with a conductive material, and it is thought that this achieves the desired conductivity, moldability, and colorability. .

As the coating conductive material, nickel, gold, silver, tin iodide, zinc oxide, tin oxide, etc. can be used, but among them, tin oxide is preferred because it has high light transmittance and is less susceptible to deterioration. Coating is done by electroless plating or chemical vapor deposition (CVD).
), physical vapor deposition (PVD), etc. It is also effective to dope a small amount of antimony oxide into the tin oxide coating layer. The thickness of the current-carrying material coating can be adjusted as long as it gives electrical conductivity to the titanium oxide particles.
Also, 10 points to ensure that the light transmittance is not lost! Below the trend is better;
In particular, about 0.2 to 0.41 is desirable. Further, it is desirable that the size of the titanium oxide coated with the current-carrying material is an average particle size of 0.5 nm or less. If it is larger than this, the structure shown in Figure 1 cannot be obtained sufficiently, and variations will occur.
-Poor conductivity.

In order to achieve the structure shown in Figure 1 and obtain the desired characteristics, the mixing ratio of carbon fiber and titanium oxide coated with the electrically conductive material was 515 to 8/2 (carbon fiber/filler).
Must be within the range.

In order to achieve a surface resistance of 108 Ω by simply blending carbon fiber alone, it is necessary to blend 200 parts or more to 100 parts of matrix resin, which reduces the amount of resin matrix and the hiding power of the resin is insufficient. , the surface of the molded tray becomes black.

On the other hand, for tin oxide coated titanium oxide alone, in order to have a surface resistance of 10"Ω or less,
It is necessary to mix 150 parts or more, and in this case, the water absorption rate of the tray molded body becomes 0.45% or more, making it impossible to maintain stable dimensions.

In addition, the blending ratio of these conductive fillers to the matrix is such that the total amount of carbon fiber and the conductive material coating tin oxide is 100 to 100 parts by weight, per 100 parts by weight of the diallyl phthalate resin and the unsaturated polyester resin.
The amount is 150 parts by weight. With this blending ratio, it seems that the structure shown in Figure 1 can be realized, and the surface electrical resistance is 103 to 1.
0”Ω can be achieved. If this mixing ratio is removed, 100Ω can be achieved.
~150 parts, it is not possible to achieve a surface electrical resistance of 10'Ω or less, and even if the amount is increased to 10"Ω or less, the tray appearance becomes black or the water absorption rate exceeds 0.45%. bring.

In addition to the above basic formulation, fibrous materials such as glass fibers and whiskers, and low water absorption fillers such as aluminum hydroxide mica powder and calcium carbonate powder can be added as fillers, if necessary.

Furthermore, coloring pigments, curing catalysts, mold release agents, etc. may be added as appropriate.

The blending of the resin molding material and the molding of the tray can be carried out by conventional methods.

[For production]

As explained above, the tray for non-black integrated circuits according to the present invention can be uniformly colored in any color by using a combination of titanium oxide coated with a current-carrying material and a suitable pigment other than black. Problems such as contamination of the surrounding area due to peeling off of the conductive paint applied to the tray have been resolved, and the IC
Increase variety control in production to improve stability and efficiency (
It can be carried out.

In addition, the combination of carbon fiber and titanium oxide coating as a conductive material maintains the desired electrical conductivity over a long period of time, and also provides excellent heat resistance.

〔Example〕

The present invention will be explained below based on Examples.

The physical properties of the phenolic resin molding material and the properties of the heat-resistant IC)ray molded product were measured according to the following methods.

(1) Charpy impact strength, specific gravity, water absorption JIS K-
Conforms to 6911.

(2) Glass transition temperature (Tg) Elongation rate (%) using a thermal analyzer (manufactured by Shimadzu Corporation)
A correlation diagram of temperature ("C) was created, and the glass transition temperature ("C) was determined from the graph.

(Measurement conditions) Test piece: 5φ x 10m round bar Heating rate: 5°C/in Measurement temperature: Room temperature to 200°C (3) Amount of warpage, dimensions, surface resistance (immediately after tray production, 150°C x 6 hours later) After being left at room temperature for 1 hour, after being left at 25°C x 60% relative humidity for 6 months) mold temperature 160°C 1 molding pressure 2oo) cgr/c+4, curing time 2 minutes, the tray shown in Figure 2 was formed by pressure molding. After molding, strain was removed using a jig at 180℃ for 2 hours, cooled, heated at 150℃ for 6 hours, left at room temperature for 1 hour, and then kept at 25℃, relative humidity 60% for 6 months. After leaving it for a while, check the warpage with a hide gauge (manufactured by Mitutoyo) and measure the dimensions with a digital caliper (manufactured by Mitutoyo).
Measured at

Warpage was determined by placing the tray on a surface plate, measuring the nine points shown in FIG. 3, and subtracting the minimum value from the maximum height to determine the amount of warpage. The dimensions are based on the dimensions immediately after the tray was manufactured, and the amount of change after that is compared to the dimensions immediately after the tray was manufactured.
It was determined as a dimensional change rate. Further, the surface resistance value was measured using a tester (manufactured by B1 Denki) by selecting a specific location and setting the distance between the electrodes as 10 m.

(4) Fillability Under the conditions shown in (3), visually observe the shape of the tip of the protrusion of the small tray lip after molding using a 10x magnifying glass, and check for incomplete filling, deformation, chipping, bending, or cracking in that part. The presence or absence of was confirmed.

(5) Colorability Under the conditions shown in (3), the color tone on the entire surface of the tray after molding was visually observed to check for color unevenness and the presence or absence of precipitation of inorganic filler on the surface.

Pitch-based graphite grade carbon fiber (manufactured by Kureha Chemical) 60〃 Tin oxide coated titanium oxide (manufactured by Mitsubishi Metals) 60〃 Carbon fiber (manufactured by Nihon Denki Kagaku) 50 □ Heavy calcium carbonate (manufactured by charged calcium) 50〃 Inorganic pigment 15 〃In addition to the above formulation, 5 parts of benzoyl peroxide as a curing catalyst and 6 parts of stearic acid as a mold release agent were added, and the mixture was uniformly dispersed and mixed with a solvent in a Henschel mixer.
60°C) for 5 to 7 minutes, and then taken out in a sheet form. This sheet material was pulverized to an appropriate size to obtain a molding material. The disc flow of the obtained molding material was 110
m/m. Using this molding material, the mold temperature was 16
0°C1 molding pressure 200kgf/ciJ curing time 2~3
A test piece was prepared by performing combination tongue molding under the following conditions, and its physical properties such as Charpy impact strength, specific gravity, and water absorption were measured. In addition, the molding material was molded and cured using a combressigon mold at 200 kgf/d at 160"C for 2 minutes, and then heated in a jig at 180"C for 2 hours to remove strain, as shown in Figure 2. A yellow IC tray with a shape was produced. Then, the physical properties of this IC tray were investigated.

For each of Examples 2 to 8, 5 parts of benzoyl peroxide as a curing catalyst and 6 parts of stearic acid as a mold release agent were added to the formulation shown in Table 1, kneaded, and crushed into a compression mold. 200kgf/d? After molding and curing at 160° C. for 2 minutes, strain relief was performed in a jig at 180° C. for 2 hours to produce yellow and red trays having the shapes shown in FIG.

Its physical properties are also shown in Table 2.

In either example, the basic physical properties of a heat-resistant tray, such as glass transition temperature of 150°C or higher, surface resistance of 1 oeΩ or lower, and water absorption of 0.45% or lower, were satisfied, and after heating at 150°C for 6 hours and at 25°C with a relative humidity of 60°C. It was confirmed that there was no increase in surface electrical resistance, and almost no change in the amount of warpage or dimensions after being left for 6 months under the % condition. In addition, good coloring was also obtained.

1 Comparison ■ 5 parts of benzoyl peroxide as a curing catalyst and 6 parts of a mold release agent were added to the formulation shown in Comparative Example 1 in Table 3 above, and then the composition shown in Figure 2 was prepared in the same manner as in Example 1. The tray shown in was manufactured.

Its physical properties are shown in Table 4, but since carbon black was blended as a conductive filler, the tray turned gray and black.
Good coloring could not be obtained.

Northern comparison fl! Using the formulation shown in Comparative Example 2 in Table 3, the tray shown in FIG. 2 was manufactured in the same manner as in Comparative Example 1.

As a result, as shown in Physical Properties Table 4, since carbon grade carbon fiber was used as the carbon fiber, the water absorption rate of the tray was 161%, and therefore, the water absorption rate was 161%.
C1 Dimensions decreased by 0.2 after being left at 60% relative humidity for 6 months.
The results were that the elongation was 0%, the amount of warpage increased by 1.1 cm, and the change over time was large, making it unsuitable for IC).

Engineering Comparison ■ A tray shown in FIG. 2 was manufactured in the same manner as in Comparative Example 1 using the formulation shown in Comparative Example 3 in Main Table 3.

As a result, various physical properties shown in Table 4 were obtained. Since graphite grade carbon fiber with a fiber length of 3 mm was used as the carbon fiber, the hiding power of the resin matrix was insufficient, and the carbon fibers precipitated on the tray surface, resulting in poor coloring properties. Furthermore, due to the long fibers of carbon fiber, the filling of the small ribs 5 becomes incomplete, and the IC
) The result was that it could not be used as a relay.

A tray shown in FIG. 2 was manufactured in the same manner as in Comparative Example 1 using the formulation shown in Comparative Example 4 in Table 3.

As a result, as shown in the physical properties in Table 4, 25 parts of titanium oxide coated with tin oxide was added to 100 parts by weight of resin.
Since 0 parts are used, the water absorption rate of the tray is 0.6%, and if left for 6 months at 25℃ and 60% relative humidity, the dimensions will increase by 16% and the amount of warping will increase by 1. However, the change over time resulted in a large void, and it was confirmed that it was unsuitable as an IC). Furthermore, the Charpy impact strength m: b<t, skgf-cm/c4, the tray became brittle, and the result was that it was not suitable as a tray material in terms of strength.

Hokudenshi 1 Using the formulation shown in Comparative Example 5 in Table 3, the tray shown in FIG. 2 was manufactured by the same method as in the comparative example.

As a result, as seen in the physical properties in Table 4, graphite grade strength = 2
Since 20 parts of the resin was mixed, the hiding power of the resin was insufficient, and carbon fibers were deposited on the surface of the tray, resulting in poor coloring properties. Furthermore, due to the large amount of carbon fiber, the filling of the small lip was incomplete, and the result was that it could not be used as an IC).

A tray shown in FIG. 2 was manufactured in the same manner as in Comparative Example 1 using the formulation shown in Comparative Example 6 in Table 3.

As a result, the various physical properties shown in Table 4 were obtained, but since the conductive filler was mixed in an amount of 80 parts by weight with respect to 100 parts by weight of the resin, the surface electrical resistance was 103 Ω or more, and the result was that it could not be used as an IC). .

The tray shown in FIG. 2 was manufactured in the same manner as in Comparative Example 1 using the formulation shown in Comparative Example 7 in Table 3.

As a result, as seen in the physical properties in Table 4, since iron powder was used as the conductive filler, the surface of the iron powder oxidized over time, and the After several months, the tray surface lost its conductivity and became unusable.

〔Effect of the invention〕

The combination of carbon fiber and current-carrying material coated titanium oxide provides the following depth:

The titanium oxide coating has the effect of hiding the black color of carbon fibers, so by using an appropriate pigment in combination, it is possible to uniformly color the carbon fiber in any color other than black.

Furthermore, it is thought that the carbon fibers and the titanium oxide coated with the electrically conductive material form a mutually connected structure, which imparts desired electrical conductivity to the tray surface and maintains it for a long period of time.

Furthermore, carbon fiber alone does not have good moldability such as filling properties due to segregation in the material, but titanium oxide coated with a current-carrying material in the form of fine particles improves the dispersibility of carbon fiber and improves the heat flow during molding. Sometimes, packing properties are improved to prevent segregation.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the structure in the matrix of the IC tray of the present invention, FIG. 2 is a schematic diagram of the IC tray, and FIG. 3 is a plan view showing the points at which the amount of warpage of the tray is measured. 1...Resin matrix, 2...Carbon black, 3...Minute conductive filler

Claims (1)

[Claims] 1. A mixture of carbon fiber and titanium oxide coated with an electrically conductive material in a weight ratio of 5/5 to 8/2 to 100 parts by weight of a resin matrix of a mixture of diallyl phthalate resin and unsaturated polyester resin. A tray for integrated circuits made of a resin molding material having a basic composition of 150 parts by weight, and having a surface electrical resistance of 10^3 to 10^8 Ω, a glass transition temperature of 150°C or more, and a water absorption rate of 0.45% or less. . 2. The integrated circuit tray according to claim 1, wherein the diallyl phthalate resin is diallyl isophthalate resin. 3. The integrated circuit tray according to claim 1 or 2, wherein the unsaturated polyester resin is a hydrogenated bisphenol-based unsaturated polyester resin. 4. The tray for an integrated circuit according to claim 1, 2 or 3, wherein the carbon fiber is a graphitized carbon fiber having a fiber diameter of 1 to 20 μm and a length of 0.1 to 1.0 mm as a center of distribution. 5. The titanium oxide coated with the electrically conductive material has a particle size of 1.0.
The tray for an integrated circuit according to any one of claims 1 to 4, wherein the tray is made of titanium oxide coated with tin oxide having a particle diameter of less than .mu.m.