JPH0689220B2 - Tray for integrated circuits - Google Patents

Description

The present invention relates to an integrated circuit (IC) or a large scale integrated circuit (LS).
I) -Hereinafter, collectively referred to as integrated circuit or IC-related to the tray for, more specifically, the surface resistance and specific gravity are small,
Moreover, the present invention relates to a heat-resistant IC tray that is little deformed after heating.

[Conventional technology]

Conventionally, in order to hold and convey the IC in the baking (heating and curing) step of the sealing material such as the epoxy resin molding material that is performed in the final step of the IC manufacturing, and the packaging step that follows the step,
For example, a plate-shaped tray having a large number of product accommodating portions formed of concave grooves is used.

There are two types of such trays, one made of metal such as stainless steel or aluminum and the other made of plastic such as polystyrene or polypropylene to which conductivity is added. The latter is used in the product packaging process. The reason why the metal and the plastic having conductivity are used is to prevent static electricity from being charged because the IC is apt to be damaged by static electricity. By the way, the reason why the two types of trays are used separately as described above is that heat treatment at 130 to 150 ° C for 4 to 24 hours is performed in the heat curing step of the encapsulant. The trays are required to have excellent heat resistance and dimensional stability, and in the product packaging process, trays holding ICs are stacked and packed, so lightness and compactness are required, and further, they are required to be inexpensive. This is because that.

Further, in the IC manufacturing factory, when the encapsulating material heat curing step is transferred to the packing step, a robot is used to transfer the IC from the metal tray to the plastic tray.

[Problems to be Solved by the Invention]

However, in the related art as described above, an operation error such as dropping the IC is likely to occur during the transfer operation of the IC by the robot, and the increase of the manufacturing cost due to the addition of the transfer operation process, etc. There's a problem.

In order to solve these problems, there is an example in which a general-purpose thermoplastic conductive material described in JP-A-58-214210 is used. However, the basic characteristic of this thermoplastic resin is that it has a glass transition temperature of at most 150 ° C.
In addition to the disadvantage that the heat treatment temperature of the encapsulant in the heat curing step cannot be increased, it takes a long processing time.
Under the heavy load condition after the IC was set, the deformation and dimensional change were severe and it could not withstand repeated use.

Therefore, in order to improve heat resistance, for example, JP-A-61-2852.
As disclosed in Japanese Patent No. 41, there is also an example in which modification is performed using a material containing a phenol resin as a main component. However, in this case, since the phenolic resin is thermosetting, it maintains a glass transition temperature of 150 ° C or higher, but the low impact resistance, which is a drawback of the phenolic resin, has not been solved, and the underlying problem Was left.

Therefore, in order to improve impact resistance, as disclosed in JP-A-61-287951, there is an example of studying a material in which a phenol resin is reinforced with fibers, but in order to improve impact resistance, It is necessary to make a highly-filled mixture with a fiber content of 30% or more,
When the fiber is highly filled, the conductivity becomes lower accordingly, so that it was unavoidable to fill a large amount of carbon black having a specific gravity of 1.8 or more. As a result, the resin content is reduced, the moldability is deteriorated, the bending amount is small, and the resin becomes very heavy.

In view of the problems of the conventional techniques as described above, the present inventors have focused their attention on phenolic resin molding materials having good heat resistance, and have conducted repeated studies in order to produce a more excellent IC tray. Rubber, conductive carbon black,
We developed a phenol resin molding material that contains an inorganic filler, fibrous substance, and fluidity-imparting agent, and applied for a patent for an IC tray with a volume resistivity of 10 ⁵ Ω · cm or less. Was carried out (Japanese Patent Application No. 62-193174). However, an IC tray made of this material has a glass transition temperature of 150 ° C. or higher, but has a specific gravity of 1.65 or higher and is heavy, and the deformation or warpage of the tray after heating is not always satisfactory.

Therefore, the present invention aims to reduce the specific gravity and the warp of the IC tray by the phenol resin molding material previously disclosed by the present inventors, solve the problems of the prior art, and heat cure the encapsulant. It is an object of the present invention to provide an IC tray that can be used consistently in processes and product packaging processes, and that has excellent conductivity, heat resistance, mechanical strength (impact resistance, warpage prevention), etc.

[Means for Solving the Problems]

The inventors of the present invention have conducted extensive studies in order to achieve the above object. As a result, a resole-type phenol resin is used in combination with an acrylonitrile butadiene (hereinafter abbreviated as “NBR”) type rubber, a natural or regenerated fibrous filler, and a conductive material. It was found that the target tray can be obtained by adding the functional carbon black, and the present invention has been accomplished.

That is, the present invention is a resol type phenolic resin 85-95.
100 parts by weight of a matrix composed of 10% by weight and acrylonitrile butadiene rubber 15 to 5% by weight, 30 to 45 parts by weight of natural or recycled fiber filler, and conductive carbon black
An integrated circuit tray made of a phenol resin molding material containing 30 to 45 parts by weight, having a surface resistance value of 10 ² to 10 ⁵ Ω, a specific gravity of 1.45 or less, and a glass transition temperature of 150 ° C. or more.

Phenolic resin is one of the thermosetting resins and has excellent heat resistance, dimensional stability, and quality stability, but it is essentially inferior in impact resistance because it is a three-dimensional cross-linking resin. In applications where impact resistance is required, it is necessary to mix a reinforcing material to maintain the strength. However, as a reinforcing material, it is necessary to use a filler made of natural or regenerated fiber such as cellulose for the purpose of reducing the weight, but in the tray for IC, it is necessary to prevent the electrification as described above. When a large amount of carbon black is blended with, it is not possible to blend a large amount of reinforcing material together with a large amount of carbon black, and the carbon black itself has poor reinforcement to phenolic resin, resulting in extremely low rigidity during heating. . Therefore, in a tray such as the present invention having a thin and complicated shape, the tray is cracked, chipped, or the like due to the impact when the IC is taken out of the tray by the robot after the product is molded or the mold is removed. It cannot be used in combination recipes. Therefore, in the present invention, it is considered that the tray which is the object of the present invention cannot be obtained if the balance between the conductivity and the thermal rigidity is considered only as the problem of the balance between the carbon black and the fibrous filler. The present invention was made by imparting flexibility to a phenolic resin itself and examining various characteristics of the tray. That is, in the present invention, 15 to 5% by weight of NBR rubber is added to 85 to 95% by weight of a phenol resin to form an organic matrix, thereby optimizing the compounding amount of carbon black and at the high temperature of the IC tray. It is possible to optimize various characteristics such as rigidity and impact resistance. The tray of the present invention containing the above organic matrix is not only not deformed or chipped at high temperatures during IC production, but also easily molded without cracks when the tray itself is molded. Moreover, since it provides a heat-resistant (glass transition temperature of 150 ° C or higher), lightweight (specific gravity 1.45 or less), and low surface resistance (10 ² to 10 ⁵ Ω) trays, both in the IC manufacturing process and the subsequent packaging process. Can be used together.

Further, the phenol resin molding material used in the present invention,
Because of its relatively good flowability, when molding IC trays, the material melts quickly at a relatively low molding pressure and is uniformly dispersed and filled up to the edges of the molding die, and then heat-cured at a set pressure. To be done. Therefore, the density of each portion of the molded IC tray is relatively uniform, and since the internal stress is small, the deformation (warpage) is suppressed.

As the resol type phenol resin used in the present invention, generally known ones are used, but liquid or solid ones such as benzylic ether type, ammonia resol type, or alkali resol type are particularly preferable. And can be used alone or in combination. These resol-type phenolic resins are particularly preferable because they generate less halogen ions or amine-based gas that corrode the metal during heat curing and have self-hardening property.

As the NBR rubber used in the present invention, generally known ones are used, but in particular, partially crosslinked NBR, bale-like one such as carboxylated NBR, powdery one or latex-like one. They are mentioned as suitable ones and can be used alone or in combination. These NBR rubbers are particularly preferable because they have a high elastic modulus retention rate at high temperatures. The NBR rubber is used in an amount of 15 to 5 parts by weight based on 85 to 95 parts by weight of the resol type phenol resin.
If it is less than 5 parts by weight, the reinforcing effect as a rubber component cannot be obtained, and if it exceeds 15 parts by weight, the phenol resin-NBR rubber matrix becomes a rubber-like substance, the bending strength and the tensile strength are lowered, and the glass transition occurs. The temperature becomes 150 ° C or lower, and the heat resistance decreases, which is not preferable.

As the natural or regenerated fibrous filler used in the present invention, generally known ones are used, but powdery, fibrous or cloth-like ones such as cellulose, cotton, rayon, cupra and the like are particularly preferable. These can be used alone or in combination. The filler is used in an amount of 30 to 45 parts by weight based on 100 parts by weight of the phenol resin-NBR rubber matrix. If it is less than 30 parts by weight, bubbles tend to be generated during the molding, and thus it becomes brittle, and if it is more than 45 parts by weight, the molding processability is poor, and there is a problem that the strength of the obtained molded product is extremely lowered.

The smaller the specific gravity of the filler, the better, but most of the natural or recycled fiber fillers that are usually obtained have a specific gravity of 1.60 or less. Inorganic fibers and inorganic fillers having a specific gravity of 1.60 or more are not preferable because the specific gravity of the obtained molded product is as high as 1.45 or more and the bending deflection amount is small.

In addition, as the conductive carbon black used in the present invention, generally known ones are used, but acetylene black, furnace black ECF and the like are particularly preferable, and they are used alone or in combination. be able to. The conductive carbon black is used in an amount of 30 to 45 parts by weight based on 100 parts by weight of the phenol resin-NBR rubber matrix. If it is less than 30 parts by weight, the surface resistance will be 10 ⁵ Ω or more and the antistatic performance will be poor, and if it exceeds 45 parts by weight, the surface resistance will be 10 ² Ω or less, on the contrary, it will be too low and it will be easy to energize, and molding processability will be improved. Since it is inferior, there is a problem that the strength of the obtained molded article is lowered.

The phenol resin molding material is composed mainly of the above-mentioned raw materials, but in addition to the above-mentioned raw materials, a curing accelerator, a release agent, a fluidity-imparting agent, a flame retardant, a dye or pigment, etc. may be appropriately added and used. it can. The phenol resin molding material can be obtained by heating, kneading, forming a sheet, cooling, and pulverizing according to a conventional method.

The IC tray of the present invention is obtained by performing compression molding, transfer molding, or injection molding using a phenolic resin molding material, the surface resistance value of which is 10 ² to 10 ⁵ Ω, and the specific gravity is 1.45 or less, The glass transition temperature is above 150 ° C.

The surface resistance of the IC tray of the present invention is within the range of 10 ² to 10 ⁵ Ω. I when the surface resistance of the IC tray is larger than 10 ⁵ Ω
If the C tray is charged with static electricity, it is likely to damage the IC, etc. On the other hand, if it is less than 10 ² Ω, the IC tray is likely to be energized, which adversely affects the IC in various ways.

The specific gravity of the IC tray of the present invention is 1.45 or less. I c
If the specific gravity of the tray for use is larger than 1.45, the weight of the tray for IC is increased, which causes troubles to the operator especially in the transportation work, etc. Moreover, since the transportation by air is particularly frequent, the cost for transporting the product becomes high.

The glass transition temperature of the IC tray of the present invention is 150 ° C. or higher. When the glass transition temperature of the IC tray becomes lower than 150 ° C, the value of the tray disappears due to deformation in the heat curing process of the sealing material such as IC. Further, the IC tray is repeatedly used several times in the process, but it becomes impossible due to deformation.

The surface resistance value, specific gravity, and glass transition temperature of the IC tray of the present invention can be basically realized in the above-mentioned phenol resin molding material, but those whose values are out of the above range are out of the scope of the present invention. is there.

In addition, the tray obtained by molding is, for example, at 180 to 200 ° C under 2
After-curing (post-curing) for up to 6 hours can further improve the heat resistance.

For example, a plate tray of 300 x 200 x 5 mm has a mold temperature of 180 to 20.
It can be obtained by performing compression molding under the conditions of 0 ° C., molding pressure of 200 to 400 kg / cm ² , and curing time of 120 to 180 seconds. The plate tray has a surface resistance value of 10 ⁴ Ω, a specific gravity of 1.35, a glass transition temperature of 162 ° C., and a warp after heating at 150 ° C. for 1 hour under normal condition and as small as 0.5 mm (10%) or less. It has become.

〔Example〕

 Hereinafter, the present invention will be described based on examples.

The physical properties of the phenol resin molding material and the warp of the plate tray were measured according to the methods described below.

(1) Bending strength, Charpy impact strength, specific gravity According to JIS K-6911.

(2) Surface resistance Measured with a shrinking piece based on JIS K-6911 using a tester manufactured by HIOKI.EE Co., Ltd.

(Measurement Method) The cord terminals of the tester are brought into contact with two points in the diameter direction of the outer peripheral side surface of the annular ridge of the shrinkable piece for measurement.

(3) Glass transition temperature 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 × 10 mm round bar Temperature rising rate 5 ° C / min Measuring temperature Room temperature to 200 ° C (4) Warp (normal state and 150 ° C, after 1 hour) Mold temperature 190 ° C, molding pressure 300kg / cm ^2. Mold a 300 x 200 x 5 mm plate tray by compression molding with a curing time of 150 seconds, and measure the warpage after heating for 1 hour at 150 ° C under normal conditions using a height gauge (Mitutoyo).

Example 1 Benzylic ether type phenolic resin (solid state) 90 parts by weight Partially crosslinked NBR (manufactured by Nippon Synthetic Rubber) 10 Cellulose (manufactured by Kojin) 35 Acetylene black (manufactured by Denki Kagaku) 35 Then, the mixture was uniformly dispersed and mixed in a Henschel mixer together with a releasing agent and a solvent, and kneaded on a hot roll (80/60 ° C.) for 5 to 7 minutes to obtain a sheet, and the sheet was taken out. This sheet-shaped material was pulverized to an appropriate size to obtain a moldable phenol resin molding material.

Using this molding material, compression molding is performed under the conditions of a mold temperature of 180 to 200 ° C, a molding pressure of 200 to 400 kg / cm ² , and a curing time of 120 to 180 seconds to create a test piece for testing and bend strength. The physical properties such as Charpy impact strength, surface resistance and specific gravity were measured. Further, the glass transition temperature and the warp of the plate-shaped tray (normal state and after heating at 150 ° C. for 1 hour) were also measured under the above conditions. The results are shown in Table 1.

Examples 2 to 12 Molding materials were prepared in the same proportions as shown in Table 1 in the same manner as in Example 1, and after the test pieces were molded, the same physical properties and the like were measured. The results are shown in Table 1.

Comparative Example 1 Injection-molding was performed at the compounding ratio shown in Table 2 to prepare a test piece for testing, and bending strength, Charpy impact strength, surface resistance, specific gravity, glass transition temperature, warpage (normal state and 150 ° C., 1 (After heating for an hour). The results are shown in Table 2.

Comparative Examples 2 to 7 Molding materials were prepared in the same proportions as shown in Table 2 in the same manner as in Example 1, and after the test pieces were molded, the same physical properties and the like were measured. The results are shown in Table 2.

[Effects of the Invention] As described above, the IC (including LSI) tray of the present invention is excellent in heat resistance, impact resistance and conductivity, and has a small specific gravity and warpage.

Therefore, when the IC tray of the present invention is used, the time of the heat curing step in the IC or LSI manufacturing plant can be shortened to 1/2 or less, and the warp of the tray is small. It can be used repeatedly several times in the process, and the product can be easily transported and packed.

In addition, by using the IC tray of the present invention, the heat curing process for ICs and the product packaging process can be integrated work, and the simplification of the process and the elimination of work mistakes during product transfer, etc. Work efficiency is improved because
The great effect is that the product value can be greatly reduced.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area // (C08L 61/10 9:02) (C08K 13/04 7:02 3:04) (56 ) Reference JP-A-59-223746 (JP, A) JP-A-61-287951 (JP, A) JP-A-61-285241 (JP, A) JP-A-62-193174 (JP, A) JP-B 56-48923 (JP, B2)

Claims (1)

[Claims] 1. A matrix consisting of 85 to 95% by weight of a resol type phenolic resin and 15 to 5% by weight of an acrylonitrile butadiene rubber, 30 to 45 parts by weight of a natural or regenerated fiber filler and a conductive carbon black. Made of phenol resin molding material with 30 to 45 parts by weight added,
An integrated circuit tray with a surface resistance of 10 ² to 10 ⁵ Ω, a specific gravity of 1.45 or less, and a glass transition temperature of 150 ° C or more.