JPH0337258A - Production of tray for conveying semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To produce a tray with a good balance among the heat resistance, mechanical strengths, moldability, and electrical properties by injection molding a compsn. obtd. by compounding a specific polyphenylene ether polymer with a carbon black and an ethylene-acrylic ester copolymer. CONSTITUTION:100 pts.wt. polyphenylene ether resin comprising 58-96wt.% polyphenylene ether copolymer and 42-4wt.% polystyrene polymer is compounded with 10-40 pts.wt. carbon black and 5-20 pts.wt. ethylene-acrylic ester copolymer to give a resin compsn., which is injection molded to produce a tray for conveying semiconductor integrated circuits. To obtain a good balance between the impact strength of the tray and the moldability of the compsn., a pref. polystyrene polymer is in a range of from a high impact polystyrene resin contg. 2-7wt.% rubber to a mixture of the high impact polystyrene resin contg. a similar amt. of rubber with a transparent polystyrene resin.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention involves injection molding a composition containing a polyphenylene ether resin, carbon black, and an ethylene-acrylic acid ester copolymer, and improving heat resistance, mechanical properties, and molding properties. The present invention relates to a method for manufacturing a tray for transporting semiconductor integrated circuit devices that has well-balanced physical and electrical properties.

[Conventional technology]

Conventionally, trays for transporting semiconductor integrated circuit devices, which are made by molding a semiconductive resin made by mixing carbon fiber, carbon black, and metal powder into thermoplastic resin, have been used to transport semiconductor integrated circuit devices (IC chips with lead wires attached to them). It is used as an electrically conductive plastic tray that can prevent electrostatic damage to the device during loading and transportation of the device (the one attached is resin-sealed).

Semiconductor integrated circuit devices are often used by mounting a plurality of semiconductor integrated circuit devices on a circuit board made of plastic, ceramic, aluminum, or the like by soldering. However, since the sealing resin is a hygroscopic resin such as epoxy resin or phenol resin, when the lead l181 of the device is soldered onto the circuit board, moisture absorbed into the sealing resin evaporates and expands. Problems such as cracks occurring in the encapsulating resin molding and further impairing the function of the IC chip are particularly likely to occur in surface-mounted semiconductor integrated circuit devices.

Therefore, in recent years, there has been an increasing number of cases in which a process of drying the device at 120 to 150° C. for several hours to several tens of hours while the device is open is performed immediately before soldering onto the circuit board.

Conventional antistatic plastic trays are used for the purpose of fully loading, storing, and transporting semiconductor integrated circuit devices, but are not suitable for the drying process of the devices. This is because antistatic plastic trays are made from thermoplastic resin, which is inexpensive and has good moldability.
For example, since the main component is a resin with a thermal deformation temperature of 100°C or less, such as polypropylene or polystyrene, it deforms significantly at temperatures above 100°C, leading to bending, breakage, and melting of the lead wires of loaded semiconductor integrated circuit devices. It has the disadvantage of causing contamination with resin. Therefore, in the drying process of semiconductor integrated circuit devices, it is necessary to
A manufactured tray is used.

[Problem to be solved by the invention]

However, trays made of metal such as aluminum have a larger fit than trays made of plastic, and 1) Furthermore, because they have extremely good conductivity, there is a risk of charge inflow from the outside, and when loading and storing semiconductor integrated circuit devices, , not suitable for use in conveyance processes. Therefore, in many cases, semiconductor integrated circuit devices are transferred from plastic trays to metal trays such as aluminum prior to the drying process, and are subjected to drying while being opened. However, the work of replacing semiconductor integrated circuit devices loaded on plastic trays with metal trays before the drying process not only causes bending and damage of the lead wires of the devices, but also increases the number of steps and increases manufacturing costs. As a result, the demand for inexpensive plastic trays that can withstand the drying temperatures during opening is increasing.

Currently, antistatic plastic trays are being developed using highly heat-resistant resins such as polycarbonate, polyamide, polyimide, and polybutylene terephthalate.

These products have sufficient heat resistance, but because they are all molded from high-temperature melting resin mixed with inorganic fillers such as carbon fiber, carbon black, and metal powder, the melting temperature and melt viscosity become high, and the surface of the molded product becomes Damn it, Flowmark.
This can easily cause problems such as short shots.

In addition, these resins require high temperature molding, so
It is difficult to reinforce with rubber, and it is not possible to provide sufficient impact resistance to the molded product.

On the other hand, there are also examples of using inexpensive and general-purpose crystalline resins such as polypropylene.

In general, the crystallinity of crystalline resins increases by mixing inorganic fillers, and the crystal restraint also increases. Although heat resistance can be improved, the thermal deformation under load is large and it is not suitable for the intended tray specifications that require stacking in an open space. Furthermore, these resins contain low-molecular-weight organic acids as crystallization accelerators, so if a tray molded from these resins is loaded with semiconductor integrated circuit devices and heated in an open environment, the tray will melt. It has the disadvantage that the organic acid eluted or volatilized from the device tends to cause troubles such as corrosion of the lead wires of the device.

As a result of intensive research, the present inventors have found that the heat resistance, mechanical properties, and moldability of injection molded compositions based on polyphenylene ether resin and styrene resin, and containing resin, carbon black, and ethylene-acrylic acid ester copolymer, have been determined. sex,
We have developed a method for manufacturing a tray for transporting semiconductor integrated circuit devices that is well-balanced in terms of electrical characteristics and cost, and have completed the invention.

[Means to solve the problem]

That is, the present invention (a) yt? +) Phenylene ether polymer 58~
100 weight polyphenylene ether resin consisting of 96itS and 42 to 4 weight polystyrene polymers! #sound k(
b) 10-40'Mf part of carbon black and (c1-
This is a method for manufacturing a tray for transporting semiconductor integrated circuit devices, which comprises injection molding a resin composition containing 5 to 20 parts by weight of a 1-terene-acrylic acid ester copolymer.

The polyphenylene ether resin used in the present invention is
It is described in US Pat. No. 3,383,435 and refers to a blend system of a homopolymer or copolymer of a polyphenylene ether polymer and a polystyrene polymer.

The blend composition of 100 parts by weight of polyphenylene ether resin is 58 to 961 parts of homopolymer or copolymer of polyphenylene ether polymer! [19
g, polystyrene polymer is 42-4% by weight. If the polyphenylene ether polymer has less 58x1# repair, moldability will be improved, but sufficient heat resistance will not be obtained for use as a tray for processing the semiconductor integrated circuit device in an oven. If the polyphenylene ether polymer exceeds 96% F by weight, the heat resistance will improve, but the moldability will decrease, making it difficult to mold the tray. Considering the balance between heat resistance and moldability, it is preferable that the polyphenylene ether polymer has a weight of 58 to 96 I#. Furthermore, the content of the polystyrene polymer mentioned here is an impact-resistant styrene resin containing 2 to 7 parts by weight of rubber or similar rubber, considering the balance between impact-reinforcing effect and moldability when used as a tray. A range of mixtures of high impact styrenic resins and clear styrenic resins containing amounts is optimal.

Next, the carbon black used in the present invention is granular or powdered conductive carbon black, for example,
There are natural black, acetylene black, furnace black, etc. The proportion of carbon bluff 2 in the composition is based on 100 parts by weight of polyphenylene ether resin.
10-40M Kurabe is preferable.

If the amount of carbon black added is less than 10 parts, the above-mentioned tray cannot exhibit satisfactory conductivity. However, if the amount of carbon black added exceeds 40 parts by weight, the fluidity of the resin decreases significantly, making it difficult to mold the tray. Generally, carbon black with a small specific surface area requires a large amount to be added, but granular furnace black is preferable from the balance of conductivity and moldability and workability. 10 to 4 parts of carbon black
It is preferable to add 0 parts by weight.

In the present invention, in order to improve moldability and impact resistance,
An ethylene-acrylic acid ester copolymer is used. Unsaturated rubber is used to reinforce general-purpose resins such as polystyrene and polypropylene resin, but since the resin used in the tray of the present invention is processed under high temperature and pressure, using unsaturated rubber will cause the rubber to deteriorate. Thermal decomposition of minutes significantly makes it unusable.

Among the ethylene-acrylic acid ester copolymers, ethylene-ethyl acrylate copolymers have the greatest effect on improving moldability and impact resistance. Ethylene is added to the blend system of polyphenylene ether polymer and polystyrene polymer.
The addition of an ether acrylate copolymer to improve moldability and impact resistance is described in Japanese Patent Publication No. 53-12539.

The ethylene-ethel acrylate copolymer used in the present invention preferably has an ethyl acrylate content of 5 to 20% by weight, considering the balance between reinforcing effect and thermal stability. In addition, the amount of ethylene-acrylic acid ester copolymer added is 1/1 of polyphenylene ether resin.
The optimal amount is 5 to 20 parts by weight per 1 part by weight of ethylene-acrylic ester copolymer.If the amount of the ethylene-acrylic ester copolymer is less than 5 parts by weight, the moldability and impact resistance of the tray can be improved. Moreover, if the amount is more than 20 parts by weight, the moldability is improved, but not only the impact resistance decreases again, but also the heat resistance decreases significantly, which does not satisfy the above specifications of the tray.Therefore, the moldability Considering the balance between impact resistance and heat resistance, it is preferable to add 5 to 2 Omf parts of the ethylene ethyl acrylate copolymer to 100 parts by weight of the polyphenylene ether resin.

Furthermore, in the present invention, various additives such as antioxidants, plasticizers, lubricants, and flame retardants may be added.

A method of implementing the present invention will be explained below. The above-mentioned various raw materials are then mixed and stirred using a well-known mixer, such as a Henschel mixer, ribbon blender, tamp 2-mixer, or the like. Next, the mixture is kneaded at 250 to 320°C using a well-known mixing machine, such as a twin-screw extruder in the same direction, a twin-screw extruder in different directions, or a pressure kneader, to form a pellet. .

Next, a tray for transporting a semiconductor integrated circuit device is made by injection molding from the semiconductive resin pelletized in the above manner.

The injection molding conditions are, for example, using a hydraulic injection molding machine with a mold clamping pressure of 160 tons, a molding temperature of 280 to 340°C, and a mold roar of 80 to 140°C.

The shape of the tray is usually 100 to 150 mm in length and 2 in width.
It is approximately 50 to 300 mm wide and 5 to 7 mm thick, and is partitioned by vertical and horizontal grids so that one semiconductor integrated circuit device can be loaded per grid.

The size of a section divided by a grid varies depending on the size of the semiconductor integrated circuit device to be loaded, but QFP type I
The mold C tray fit is -side 10 to 40B8 degrees. In addition, a hole for ejecting the semiconductor integrated circuit device is formed in the compartment partitioned by the grid, and a width of 0.2 to 0.5 mm is provided between the hole and the grid so as to surround the hole. Height 0.2~1
, OB-sized micro-lips are formed, and the loaded semiconductor integrated circuit devices are mounted and fixed by the micro-lips, and care is taken to prevent the lead wires from touching the tray (FIG. 1). tf
c. On the back side of the tray, lips for assisting flow may be provided vertically and horizontally so as to connect the sections partitioned by the lattice (Fig. 2).

〔Example〕

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

Examples 1-6, Comparative Examples 1-4 (2) Compounding: The compositions shown in Tables 1 and 2 were used.

(2) Mixing: The raw material powders from the formulations shown in Tables 1 and 2, excluding carbon black, were mixed for 2 minutes using a Henschel mixer. Thereafter, all components including carbon black were mixed in a tumbler mixer for 6 minutes.

■ Mixing and pelletizing: Using a co-directional twin-screw extruder (Ikegai Steel Co., Ltd., PCM-45), mix the raw material powder.
Cylinder temperature 280℃, cylinder 2 rotation speed 14 Or
The mixture was cross-wired and pelletized under pm conditions.

(2) Injection molding: Test pieces for physical property evaluation and QFP type IC trays were molded from the prepared pellets using the injection molding method.

Table 3 shows examples of molding conditions for QFP type IC).

■Table 4 shows the general physical property evaluation results. Table 5 shows heat resistance test results. I wrote down the results.

Surface resistance measurement method Two test pieces were prepared by injection molding method.
12 ()nX 3n+) was created.

Apply silver paint T51 at 10m intervals at 9 locations on the pretreatment nibrate.
It was coated on a 111 x 10 m area and dried at room temperature to create a silver electrode on the plate.

Measurement: Advantek digital multimeter IR-
6853, the resistance value between silver electrodes was measured.

The resistance value is the average value of n-9 locations/sheet. did.

Heat resistance test method for QFP type IC tray Heat treatment ■Heating was done in the open with six trays stacked on top of each other.

125°C, 135°C, 145°C for 24 hours ■ Six heated trays were stacked and left at room temperature; 23″cx5
0%RHx24 hour measurement method ■The following measurements were performed before and after heat treatment; Number of samples nwm
(5 sheets 71 conditions/external dimensions: Vertical and horizontal dimensions were measured with a caliper with an accuracy of 1/100n; 4 sides/a small amount of each sheet was measured with a hide gauge with an accuracy of 1/100 mm; 15 points/sheet・Surface resistance: The surface resistance value was measured between two points at 10m+ intervals on the front and back of the tray; 12 points/one side ・Impact strength: The center of the tray was measured at 6.55m x 12.71
The trays of the present invention, which are injection molded using the specified resin composition, have a heat-resistant property. The present invention is a tray for transporting semiconductor integrated circuit devices that has well-balanced characteristics in terms of properties, mechanical properties, moldability, electrical properties, and price.

[Brief explanation of drawings]

Figures 1 (at, (b) and (c) are a top plan view and a side view of the tray used for testing the present invention, and Figure 2 is a back plan view. Reference numeral 1...・Lattice 4...Lip for flow assistance 2...Hole
5... Lip for fluid support 3... Minute lip

Claims (3)

[Claims] (1) (a) Polyphenylene ether polymer 58-96
100 parts by weight of a polyphenylene ether resin consisting of 42-4% by weight of polystyrene polymer, (b) 10-40 parts by weight of carbon black, and (c) ethylene-
1. A method for producing a tray for transporting semiconductor integrated circuit devices, which comprises injection molding a resin composition containing 5 to 20 parts by weight of an acrylic ester copolymer. (2) The method for producing a tray according to claim 1, wherein the polystyrene polymer is an impact-resistant styrene resin containing 2 to 7% by weight of rubber or a mixture of an impact-resistant styrene resin and a transparent styrene resin. (3) The method for producing a tray according to claim 1, wherein the carbon black is in the form of granules.