JP3444414B2 - Molded products for packaging electronic components - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a molded article for packaging electronic parts such as ICs.

[0002]

2. Description of the Related Art A container obtained by injection molding such as an injection molding tray, a vacuum molding tray, a carrier tape (also called an embossed carrier tape) as a molded body for packaging an electronic component such as an IC which is easily destroyed by static electricity. A molded body obtained by molding a resin sheet by vacuum molding, pressure molding or the like is used. It is common for these molded products to impart conductivity in order to easily remove static electricity generated by contact and friction between electronic parts and molded products, and to make the generated charge evenly dispersed in the molded product and less likely to generate a potential difference. Is being carried out. For example, a metal material having conductivity, a resin in which carbon fiber or carbon black is kneaded is used, or a conductive material such as carbon black is applied to the surface of the molded body to impart conductivity. It is used.

These molded articles for packaging electronic parts have a feature that electricity can easily escape by grounding when static electricity is generated, and have prevented the electrostatic breakdown of electronic parts. But,
Even in such a case, there are cases where the electrostatic breakdown cannot be completely prevented. In particular, as the wiring inside the electronic components becomes finer with the high integration of electronic components, even when a conductive resin is used as a molded body for packaging electronic components, damage due to static electricity on the surface of the electronic components, Destruction has become a problem.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a container suitable for preventing electrostatic breakdown of electronic parts.

[0005]

[Means for Solving the Problems] A conventional molded article for packaging electronic parts aims to eliminate static electricity generated by protecting the electronic parts from electrostatic breakdown by imparting conductivity to them. The "easiness of generation" of static electricity generated by friction with electronic parts has not been fully considered. Even if the molded product for electronic component packaging is conductive,
The IC is charged by friction between the molded body for packaging electronic parts and the IC, and the sealing material on the surface of the IC is easily charged. Further, the sealing material on the surface of the IC exterior is non-conductive. No consideration was given to the fact that the electric charges generated in could not be completely removed even if the molded body for packaging electronic parts was grounded. According to the measurement by the inventors, even if a molded article for packaging electronic parts having conductivity is used, if the container containing the IC in an insulated state is vibrated, the charging voltage on the surface of the IC is 10,000 V, 2 It may exceed 10,000V. The static electricity charged on the surface of the IC is sufficient to destroy the IC.

The present invention aims to reduce the destruction of electronic parts by making it difficult to generate static electricity even when the electronic parts and the molded body rub. That is, the present invention is a molded article for packaging electronic parts, comprising a graft copolymer obtained by grafting an olefin polymer with a styrene polymer and / or an acrylic ester polymer. Here, the molded body for packaging electronic components is a molded body for packaging electronic components such as ICs, and means, for example, a sheet for packaging electronic components or a container for packaging electronic components. The electronic component packaging container includes, for example, an injection tray, a vacuum forming tray, a magazine, a carrier tape and the like. The molded product of the present invention has a low absolute value of electrostatic charging voltage on the surface of the electronic component, which is generated by friction with the electronic component, and forms a resin sheet or a resin composition which forms the surface of the resin sheet with the electronic component such as IC. Absolute value of charging voltage due to friction with 5000V
Or less, preferably 2000 V or less, I
It is possible to suppress electrostatic damage and destruction of C.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

(Molded product) A molded product for packaging electronic parts, which comprises a graft copolymer obtained by grafting an styrene polymer and / or an acrylic ester polymer on an olefin polymer It may be composed of only a polymer or may further contain other components within a range not impairing the object of the invention. In addition, there are a molded product which contains the graft copolymer as a whole and a molded product which has a surface layer containing the graft copolymer on at least the surface in contact with the electronic component. As examples of these, the former is a single-layer sheet containing a graft copolymer, and the latter is a substrate layer and a surface layer containing a graft copolymer on the surface in contact with an electronic component. There is also a multi-layered sheet obtained by the above, and further a multi-layered sheet having surface layers on both sides of the base material layer.

Examples of molded articles for packaging electronic parts include vacuum molded trays, embossed carrier tapes and the like obtained by subjecting the sheet to secondary molding such as pressure molding and vacuum molding.

The graft copolymer is a copolymer obtained by grafting an olefin polymer with a styrene polymer and / or an acrylic ester polymer (hereinafter simply referred to as a graft copolymer). The olefin polymer is a polymer of olefin, and includes, for example, an olefin homopolymer, a copolymer of a plurality of olefins, and a copolymer of olefins. An ethylene-based polymer, a propylene-based polymer, and an ethylene-glycidyl methacrylate-based copolymer can be preferably used.

The styrene-based polymer is a polymer obtained by polymerizing styrene as a main component, and examples thereof include a styrene polymer which is a styrene homopolymer and a styrene copolymer. As the styrene copolymer, for example, an acrylonitrile-styrene copolymer can be preferably used. The acrylic acid ester-based polymer means a homopolymer of methyl methacrylate or a copolymer of a monomer copolymerizable with methyl methacrylate. As the copolymerizable monomer, methacrylic acid ester having 2 to 4 carbon atoms, acrylate ester having 1 to 8 carbon atoms such as butyl acrylate, styrene, α-methylstyrene, acrylonitrile, acrylic acid, and other Examples include ethylenically unsaturated monomers.

When the molded product or sheet has a multi-layer structure, at least one of the layers containing the graft copolymer as a main component is provided with conductivity such that the volume resistivity is 10 ² to 10 ¹² Ω. It is preferable that the layer is provided, and it is further preferable that this layer is in contact with the layer containing a graft copolymer as a main component. The method of imparting conductivity is not particularly limited, and various known methods can be used. Specific examples thereof include a method of dispersing an ionic antistatic agent, a method of dispersing a conductive filler such as carbon black and a metal filler, and a method of dispersing a conductive polymer such as polyaniline, polythiophene and polypyrrole.

The lower the absolute value of the frictional electrification voltage of the molded article or sheet with the electronic component is, the better. The value varies depending on the electronic component, but it is 5000 V or less, preferably 2000.
It is preferably V or less. The resin composition containing a graft copolymer as a main component is a polyethylene resin, a polystyrene resin, an acrylic resin, if it satisfies the above-mentioned performance.
It is possible to add any thermoplastic resin such as polyester resin. In addition, talc, mica, silica, alumina, potassium titanate whiskers, metal oxides such as calcium oxide, calcium carbonate, etc., unless the characteristics that the charging voltage with the electronic component due to friction with the intended electronic component is small are not impaired. , Magnesium carbonate, calcium silicate,
It is also possible to add fillers such as glass fibers, glass flakes and glass beads. In addition, as well as non-carbon fibers, steel fibers, aluminum fibers, brass fibers,
Copper fiber, metal fiber such as stainless fiber, carbon fiber,
It is also possible to add conductive substances such as metal-coated carbon fibers, carbon black, graphite powder, and metal-coated glass fibers, and it is also possible to make the resin conductive by adding these substances. It is no problem that the molded article for packaging electronic parts in the present invention has conductivity,
This is one of the preferred forms.

If the absolute value of the charging voltage due to the friction with the electronic component is large, the electronic component such as the IC chip is likely to be damaged or broken, which is a problem. In addition, even in the case of components that are less likely to be damaged or damaged by static electricity, static electricity may be adsorbed to the container, resulting in a reduction in workability, which is not preferable.

The molded product of the present invention contains a flame retardant such as a reinforcing material, a foaming agent, a lubricant, an antioxidant, an anti-UV agent, a coupling agent, a flame retardant, and antimony trioxide as long as the object of the present invention is not impaired. It is also possible to mix an auxiliary agent, a heat resistance stabilizer, and a coloring agent.

The method for producing a molded body or sheet is not particularly limited. It can be carried out by an injection molding method or a known sheet molding method such as vacuum molding, pressure molding, press molding of a sheet, for example, T die molding by an extruder, calender molding, solvent casting method and the like. When using a plurality of resins, if necessary, a tumbler or a raw material mixed with a magella, a melt-kneading extrusion using a single-screw extruder or a twin-screw extruder, a resin obtained by melt-kneading with a Brabender, etc. Can be made into a sheet by the method described above.

Further, the sheet of the present invention can be multi-layered, and a layer for modifying mechanical properties such as rigidity and strength in a lower layer or an intermediate layer of the sheet, an inexpensive layer for cost reduction, It is possible to provide one or more conductive layers or the like for obtaining a stable static electricity suppressing effect. As a method for forming a multilayered sheet, a known method such as a co-extrusion method using a plurality of extruders, an extrusion laminating method, a thermal laminating method, or a dry laminating method using an adhesive or the like can be used.

The molded article for packaging electronic parts of the present invention is a container for housing electronic parts which are particularly prone to electrostatic damage, such as a hard tray for IC chips, a soft tray for IC chips and a carrier tape for IC chips. is there. Further, by using a container that does not easily generate static electricity, electrostatic adsorption of electronic components to the container can be suppressed, and therefore, it can be used for a bare chip tray, a capacitor carrier tape, and the like. The present invention will be further described below with reference to examples.

[0019]

EXAMPLE (Example 1) Polyethylene-g-polystyrene resin as graft copolymer (meaning that polystyrene is grafted on polyethylene, the same shall apply hereinafter.
Using Modiper A-1100 NOF CORPORATION φ65
A 0.5 mm thick sheet was obtained using a mm extruder. A molded body was obtained from the obtained sheet by vacuum molding as shown in FIG.

(Example 2) Polypropylene-g-polystyrene resin (MODIPA A-3100 NOF CORPORATION)
And polystyrene resin (Toyo Styrol HI-U2
-301U A conductive resin composition obtained by kneading 29 wt% of carbon black (Denka Black Granular Denki Kagaku Kogyo Co., Ltd.) into Toyo Styrene Co., Ltd. was used.
The polypropylene-g-polystyrene resin layer was 200 μm by the feed block method using a 65 mm extruder,
Conductive resin composition layer is 100 μm, total thickness is 300 μm
Got a sheet of. A molded body was obtained from the sheet in the same manner as in Example 1 so that the polypropylene-g-polystyrene resin layer was on the inner surface. (Example 3)

The same procedure as in Example 1 was carried out except that Modiper A-4200 was used as the ethylene-glycidyl methacrylate copolymer-g-methyl methacrylate resin.

The frictional electrification voltage was measured using the molded article of each example and an electronic part (IC of QFP 32 mm × 32 mm size) using an epoxy resin as a sealant. The friction charging voltage was measured by placing the molded body of FIG. 1 on a friction machine in an environment of temperature: 25 ° C. and relative humidity: 60%, and neutralizing the molded body using static elimination. On the other hand, for the IC to be the object of friction, the terminal was cut and the same portion was closed with an insulating tape in order to prevent the movement of charges from the IC metal terminal for the purpose of accurately measuring the charging voltage. The IC was subjected to static elimination by static elimination, and then put into a molded body and rubbed. Friction conditions are as shown in FIG. 1, vibration width: 22 mm, friction speed: 300
The speed was round trip / minute. After the end of rubbing, the charging voltage at the rubbing point of the IC is measured, and the rubbing frequency is 50 times, 200 times, 50 times.
The charging voltage at 0 times and 20000 times was measured. The results are shown in Table 1, but almost no increase in charging voltage was observed in the same composition. In addition, charge voltage measuring instruments SK-030 and SK-200 manufactured by KEYENCE CORPORATION were used for measuring the charge voltage.

(Comparative Example 1) As a resin, a triboelectrification test was conducted in the same manner as in Example 1 on a resin composition of 100 parts by weight of polystyrene (Toyo Styrol HI-U2-301U Toyo Styrene Co., Ltd.). The relationship was measured. The results are shown in Table 1. The friction significantly increased the charging voltage.

(Comparative Example 2) As a resin, 100 parts by weight of polystyrene (Toyo Styrol HI-U2-301U Toyo Styrene Co.) and carbon black (acetylene black granular Denki Kagaku Kogyo Co., Ltd.) 2 as a conductive filler were used.
A triboelectrification test was conducted in the same manner as in Example 1 on the resin composition having 0% by weight added and having a surface resistivity of 10 ⁴ Ω / □, and the relationship between the number of rubbing and the electrification voltage was measured. The results are shown in Table 1, but the charging voltage greatly increased due to friction despite having conductivity.

[0025]

[Table 1]

[0026]

EFFECTS OF THE INVENTION By using a resin containing a graft copolymer obtained by grafting an olefin polymer with a styrene polymer and / or an acrylic ester polymer, electrostatic breakdown of electronic parts can be prevented. It is possible to obtain a container suitable for

[Brief description of drawings]

FIG. 1 Molded product used for triboelectrification test with IC chip

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI // C08L 51:06 C08L 51:06 (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65D 65/02 B32B 27 / 32 B65D 73/02 C08F 255/00 C08J 5/00 CES C08L 51:06

Claims (6)

(57) [Claims] 1. A molded article for packaging electronic parts, comprising a graft copolymer obtained by grafting a styrene polymer and / or an acrylate polymer on an olefin polymer on the surface in contact with the electronic part. 2. A packaging material for electronic parts having a surface layer containing a graft copolymer obtained by grafting a styrene polymer and / or an acrylate polymer on an olefin polymer on at least one surface of a molded article. Molded body. 3. The olefin polymer is an ethylene polymer,
Any one or more of a propylene polymer and an ethylene-glycidyl methacrylate copolymer, and the styrene polymer is a styrene polymer and / or acrylonitrile-
The molded article for packaging electronic parts according to claim 1 or 2, which is a styrene copolymer. 4. The absolute value of electrostatic charging voltage of the surface of the electronic component generated by friction between the surface containing the graft copolymer and the electronic component is 5000 V or less, according to any one of claims 1 to 3. A molded article for packaging electronic components according to. 5. A molded article is a sheet according to claim 1 to claim
The molded article for packaging electronic components according to any one of 4 above. 6. The molded body for packaging electronic parts according to claim 1, wherein the molded body is a carrier tape.