JPH0376010B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a conductive carrier tape for taping and packaging chipped electronic components such as semiconductors, resistors, and capacitors used in electronic devices.

<Conventional technology> As electronic devices have become smaller and more sophisticated in recent years, the electronic components used have also become more chipped.
Demand for taping packaging, ie, carrier tape, for mass production and automatic insertion machines is increasing.

Chip-based electronic components such as resistors, capacitors, coils, and semiconductors can be packaged using taping, such as paper tape with square holes punched out,
Types with round feed holes, molded plastic tape recessed square holes, and round feed holes are known.

By the way, electronic components such as semiconductors that are sensitive to static electricity are easily damaged by static electricity before they are attached to electronic circuits, and even after they are attached to electronic circuits, which poses a major problem. There is.

Therefore, in order to protect electronic components from static electricity, plastic films mixed with conductive substances such as carbon and metal powder have conventionally been used as carrier tapes for electronic components.

However, since all of these are opaque,
As it is, it is impossible to confirm the existence and damage of the electronic components inside, or to identify the type. On the other hand, there are plastic films mixed with antistatic agents, but these have considerably high electrical resistance per unit area and are completely inadequate for protecting electronic components. is sensitive to moisture and lacks stability.

<Problems to be Solved by the Invention> The present invention eliminates the above-mentioned drawbacks, and allows the electronic components inside the carrier tape to be seen through, while at the same time having a carrier tape that is sufficient to protect the electronic components from static electricity. The present invention provides a carrier tape for electronic components that has conductivity.

<Means for Solving the Problems> In other words, the present invention provides an electronic component comprising a base tape in which storage recesses are formed at regular intervals, and a cover tape for sealing electronic components after storing them in the storage recesses. A carrier tape for electronic components, characterized in that at least the base tape is provided with a conductive layer mainly composed of a conductive material made by coating the surface of a transparent flat material with a conductive material. The company provides carrier tapes.
Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of a carrier tape showing an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1. The base tape 1 is composed of a transparent plastic film 1-1 and a conductive layer 1-2. , storage recesses 3 for chip-type electronic components 2 are continuously formed at regular intervals. Further, tape feed holes 4 are continuously bored at a constant pitch on one or both sides of the base tape 1.

After the chip-type electronic component 2 is assembled into the storage recess 3 of the base tape 1, the cover tape 5 is adhered.

Plastic films constituting the base tape in the present invention include polyester films,
Acrylic film, vinyl chloride film, fluororesin film, styrene film, polypropylene film, polyethylene film, nylon film, ionomer resin film, ethylene film
Vinyl acetate copolymer film and any other possible packaging materials can be used.

In addition, the transparent plastic film is 50 μm ~
A thickness of 300 μm is desirable. If the transparent plastic film is thinner than 50 μm, it is extremely thin and extremely weak, so it is useless as a packaging material. If the transparent plastic film is thicker than 300 μm, it will be too stiff and have a strong repulsive force, making it extremely inconvenient to handle during embossing and after embossing.

The transparent plastic film is not necessarily a single layer, but can also be made into two or more layers by laminating various plastic films together, extruding a suitable resin onto a single plastic film, laminating it, or coating it. .
Further, the conductive layer can be obtained by coating a transparent plastic film with a coating liquid in which a conductive material made by coating the surface of a transparent flat plate-like material with a conductive substance is dispersed in a binder resin. In this case, the flat material constituting the conductive material functions as a support for the conductive material, and generally has a major axis in the range of 1 to 100μ,
A tabular material having a long axis to short axis ratio of 1 to 30 and a short axis to thickness ratio of 5 or more is used. Also, the plate-like material must itself be translucent. Here, “translucent plate-like material” refers to a plate-like material
10wt%, liquid paraffin (Japanese Pharmacopoeia) 90wt%
A flat material that has a transmittance of 50% or more for light at a wavelength of 600 nm when a mixture of the above is applied to a 3 mm thick quartz glass with a coating film thickness of 60 μm. The material of the flat material of the present invention does not matter as long as it is translucent. However, its refractive index is 1.5 ~
It is preferably in the range of 2.5. Therefore, specific examples of the tabular material that can be used in the present invention include mica, illite, prabasite, kaolinite, glass pieces, and the like.

The surface of the light-transmitting plate material is coated with a conductive material, and the thickness of the coating layer is in the range of 70 to 1200 Å, preferably 200 to 1000 Å. If the thickness of the coating layer is less than 70 Å, it will not be possible to impart the desired conductivity to the material of the present invention, and if it exceeds 1200 Å, the transparency of the material will deteriorate. The conductive material of the present invention is composed of a metal oxide doped with a different metal.
0.1-30 wt%, preferably 3-15 wt% antimony-doped tin oxide and 0.1-15 wt%, preferably 5-15 wt% antimony, and 0.01-5 wt%
%, preferably from 0.05 to 0.5 wt. % of tellurium, and in the case of indium oxide, mention may be made of indium oxide doped with 0.1 to 20 wt. % of tin. others,
For example, CdSnO ₂ , Cd ₂ SnO, In ₂ TeO ₃ , Cdln ₂ O ₄ and the like can also be used as the conductive material in the present invention.

Furthermore, the method for producing a conductive material according to the present invention includes, for example, depositing the pre-drive of the conductive material in the form of a metal hydroxide uniformly on the surface of the light-transmitting flat material, and then Wash and dry the hydroxide-coated platelets, then add 350 to 850
It is manufactured by firing at a temperature of ℃.

The above conductive material is dispersed in a binder resin such as vinyl chloride/vinyl acetate copolymer, polyvinyl chloride, polyester resin, or acrylic resin to form a coating liquid, and the coating liquid is used for electronic parts of the present invention. Desired conductivity can be imparted to the carrier tape of the present invention by coating at least the base tape and the cover tape constituting the carrier tape to form a conductive layer. That is, a better effect can be obtained by applying the conductive layer to both the base tape and the cover tape, but sufficient effects can be obtained even when the conductive layer is applied only to the base tape.

Further, when providing the conductive layer on the base tape, it is effective to provide the conductive layer on only one side of the base tape, but it is preferable to provide the conductive layer on both sides with a target coating amount of 5 g/m ² (per side). By providing such a conductive layer, the surface resistance is maintained at 10 ⁸ Ω or less and the desired conductivity is imparted to the present invention.

The raw base tape obtained in this way is slit into a tape shape, and further, storage recesses are formed by embossing and tape feed holes are punched by sprocketing.The base tape constitutes the carrier tape of the present invention. can be obtained.

In addition, the cover tape for storing and sealing the chip parts in the storage recess of the base tape is preferably a transparent film such as polyethylene terephthalate film, and is attached onto the storage recess of the base tape by means such as pasting with an adhesive or heat sealing. The carrier tape for electronic components of the present invention can be produced by sealing the carrier tape from the above.

<Example> The present invention will be explained in detail with reference to Examples below.

Example 1 A conductive coating liquid having the following composition was applied to both sides of a hard polyvinyl chloride film having a thickness of 200 μm so that the absolute dry coating amount was 5 g/m ² per side to prepare a base tape material.

Conductive mica (MEC-300, manufactured by Teikoku Kako Co., Ltd.)
10 parts by weight Polyester resin (Nitsuka Coat P-52, manufactured by Nippon Kakoshosho Co., Ltd., solid content concentration 30%) 8 parts by weight Toluene 50 parts by weight Methyl ethyl ketone 50 parts by weight The above conductive mica has a Sn content of 12.6 in terms of _SnO2 .
%, and contains 1.8% Sb in terms of Sb ₂ O ₃ .

The surface resistivity of the obtained base tape was measured using a P-601 type resistance measuring device manufactured by Kawaguchi Denshi Seisakusho, and it was found to be 5.9×10 ⁶ Ω.
It was confirmed that the total light transmittance was 85% or more. After the raw base tape is slitted, embossed, and sprocketed, it is wound onto a reel, and then semiconductor chips are loaded in a taping magazine and sealed with a cover tape to produce the carrier for electronic components of the present invention. Got the tape. After the carrier tape had been stored for a specified period of time, the cover tape was removed in order to attach it to the semiconductor device, and when it was attached to the semiconductor device, it was installed without any problems such as the semiconductor chips popping out due to static electricity. I was able to perform the operation. Further, when a mounting test was conducted on a semiconductor device equipped with the semiconductor chip, a high degree of reliability was confirmed, and it was confirmed that the semiconductor chip did not suffer any electrostatic damage while being stored on the carrier tape. Furthermore, since the carrier tape had excellent light transmittance, it was possible to sufficiently identify the chip parts housed within the carrier tape from the outside.

Example 2 A carrier tape for electronic components of the present invention was obtained in the same manner as in Example 1, except that a conductive coating liquid having the following formulation was used instead of the conductive coating liquid of Example 1.

Conductive mica (MEC-300, manufactured by Teikoku Kako Co., Ltd.)
10 parts by weight Vinyl chloride/vinyl acetate copolymer resin (Denkaratsuku #64, manufactured by Denki Kagaku Kogyo Co., Ltd., solid content concentration 43
%) 10 parts by weight Toluene 70 parts by weight Ethyl acetate 30 parts by weight The obtained carrier tape for electronic components was evaluated in the same manner as in Example 1, and the surface resistivity was 7.1×.
10 ⁷ Ω, total light transmittance of 85% or more, and no problems due to static electricity were observed during mounting tests.
Furthermore, since the carrier tape had excellent light transmittance, it was possible to sufficiently identify the chip parts housed within the carrier tape from the outside.

Example 3 A carrier tape for electronic components of the present invention was obtained in the same manner as in Example 1, except that a conductive coating liquid having the following formulation was used instead of the conductive coating liquid of Example 1.

Conductive mica (MEC-300, manufactured by Teikoku Kako Co., Ltd.)
10 parts by weight Vinyl chloride resin (Denka #1000, manufactured by Denki Kagaku Kogyo Co., Ltd., solid content concentration 30%) 10 parts by weight Toluene 50 parts by weight Ethyl acetate 50 parts by weight The obtained carrier tape for electronic components was used as Example 1. When evaluated in the same way, the surface resistivity was 7.1×
10 ⁶ Ω, total light transmittance of 85% or more, and no problems due to static electricity were observed during mounting tests.
Furthermore, since the carrier tape had excellent light transmittance, it was possible to sufficiently identify the chip parts housed within the carrier tape from the outside.

Comparative Example An original base tape for comparison was prepared by applying a conductive coating liquid having the following composition to both sides of a hard polyvinyl chloride film with a thickness of 200 μm at an absolute dry coating amount of 5 g/m ² per side. .

Conductive TiO ₂ (ECTT-1, manufactured by Titan Kogyo Co., Ltd.)
10 parts by weight Polyester resin (Nitsuka Coat P-52, manufactured by Nippon Kakoshosho Co., Ltd., solid content concentration 30%) 30 parts by weight Toluene 50 parts by weight Methyl ethyl ketone 50 parts by weight The above conductive TiO ₂ is 0.26 μm ultrafine TiO ₂ Sn and Sb are baked onto the surface of TiO ₂ Sn−(Sb).
It has the structure _O2 .

The surface resistance of the base tape obtained was 6.1×
10 ⁷ Ω, and when a semiconductor chip mounting test was conducted using the carrier tape for electronic components as described in Example 1, no damage due to static electricity was observed, but the total light transmittance was 20% or less. However, we were unable to achieve our desired goals and obtain sufficient transparency. In addition, in order to obtain a sufficient total light transmittance, that is, 80% or more, the conductivity in the binder must be
The content of TiO ₂ must be 5% or less, and in this case the surface resistance becomes 10 ¹⁰ Ω or more, making it impossible to obtain sufficient conductivity.

<Effects of the Invention> Since the present invention has the above-mentioned configuration, it is possible to maintain sufficient transparency and conductivity in the carrier tape for electronic components, and since the shape of the conductive material is flat, it is possible to maintain sufficient transparency and conductivity in the carrier tape for electronic components. Since the coating is oriented parallel to the base film surface and the coated surface is smooth, it has the effect of improving workability during embossing and bonding with cover tape. Furthermore, since it is a relatively inexpensive conductive material, it is advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a plan view of a carrier tape showing an embodiment of the present invention, and FIG. 2 is a sectional view of FIG. 1. DESCRIPTION OF SYMBOLS 1... Base tape, 1-1... Transparent plastic film, 1-2... Conductive layer, 2... Chip type electronic component, 3... Storage recess, 4... Tape feed hole, 5... Cover seal.

Claims (1)

[Claims] 1. A carrier tape for electronic components comprising a base tape in which storage recesses are formed at a constant interval, and a cover tape for sealing electronic components after storing them in the storage recesses, at least the base tape is transparent. A carrier tape for electronic components, characterized in that a conductive layer is provided, the main component of which is a conductive material formed by coating the surface of a light-sensitive flat material with a conductive material.