JP3181188B2 - Cover tape for embossed carrier tape for surface mounting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of protecting chip-type electronic components for surface mounting from contamination when storing, transporting, and mounting the chip-type electronic components, and having a function of aligning and removing the electronic components for mounting on an electronic circuit board. The present invention relates to a cover tape that is heat-sealed to a plastic embossed carrier tape having a storage pocket in a package.

[0002]

2. Description of the Related Art In recent years, chip-type electronic components for surface mounting, such as ICs such as memories and logics, transistors, diodes, and capacitors, have been designed according to the shape of the electronic components.
It is packaged in a package consisting of a plastic embossed carrier tape having continuously formed embossed pockets that can be stored and a cover tape that can be heat-sealed to the carrier tape and tested. After peeling off the cover tape of the package, the electronic components of the contents are automatically taken out and surface-mounted on an electronic circuit board. The mounting technology is becoming more sophisticated and accurate year by year, and production efficiency is being improved.
For this reason, the mounting speed of electronic components has also rapidly increased,
Correspondingly, when the cover tape is peeled off at the time of mounting and electronic components are taken out, the cover tape has been remodeled in a direction in which the cover tape is wound tightly so that the cover tape can be taken out without causing peeling failure. Also, the mounting tact time is 0.1
Very fast, less than a second / tact,
A mechanism in which the cover tape is instantaneously peeled off in less than 0.1 second has begun to become mainstream. For this reason, the cover tape is instantaneously peeled off with a very strong force, and a larger impact force than before is applied.

[0003] Under such circumstances, there has recently been a frequent occurrence of so-called "tape breakage", in which the cover tape cannot withstand the stress at the time of peeling, and the cover tape is cut.
This is a major factor in lowering production yield. In the past, the mounting speed was not so fast that the trouble was not so great, but as a countermeasure, only the thickness of the outer layer having high mechanical strength was increased. Current,
Most cover tapes on the market have a simple structure of two layers, a base layer and a sealant layer. However, the sealant is relatively flexible because its low-temperature sealing property with the carrier tape is the highest priority, and it is relatively flexible and has heat resistance and mechanical strength. Is a low resin. As a sealant, resins with excellent tear strength and impact resistance include low-density olefins such as LLDPE and VLDPE, but their molecular weight and composition distribution are wide, and the odor of the film is low in the low molecular weight region and the heat sealing property is impaired in the sticky polymer region. Because of the poor transparency, the resistance to tape breakage mostly depended on the mechanical strength of the outer layer. However, if the outer layer is too thick, the sealing performance at low temperatures deteriorates, and there is a limit in measures taken only by the outer layer thickness of a single layer,
When a very strong seal is made, the notch will cause the tape to break, and no sufficient measures have been taken.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention completely prevents the breakage of the tape when the cover tape is peeled off at the time of mounting, and at the same time, has a mechanical strength that does not impair the low-temperature sealability or transparency. And a cover tape that is heat-sealed to a plastic embossed carrier tape.

[0005]

According to the present invention, there is provided a biaxially stretched film as an outer layer, and an ethylene-α-olefin polymerized by a metallocene catalyst having excellent tear resistance, impact resistance and transparency as an intermediate layer inside the film. A composite film having a surface resistance value of 10 ¹³ or less and a total light transmittance of 70% or more of an adhesive layer composed of a polymer and a heat seal lacquer type thermoplastic adhesive in which conductive fine powder is dispersed in the adhesive layer. Or, the biaxially stretched film on the outer layer, the layer with excellent impact resistance inside, the tear resistance as the middle layer on the inside,
An adhesive layer composed of an ethylene-α-olefin copolymer polymerized with a metallocene catalyst having excellent impact resistance and transparency, and a heat-sealable lacquer-type thermoplastic adhesive in which conductive fine powder is dispersed in the adhesive layer. The inventors have found that a composite film having a surface resistance value of 10 ¹³ or less and a total light transmittance of 70% or more can be a cover tape having good characteristics, and have completed the present invention.

That is, the present invention is a cover tape which can be heat-sealed on a plastic carrier tape in which storage pockets for storing chip-type electronic components are formed continuously.
In the cover tape, the outer layer is a biaxially stretched film of either polyester or polypropylene, and the middle layer has a tear strength (JIS K 7128) of 100 kg / cm or more and a tensile impact strength (ASTM D 1822) of 100 kg-cm. / Cm ²
As described above, the haze (JIS K 7105) is 15% or less, the density of the resin is 0.990 to 0.925 g / cm ³ , and the melting point is 110.
An ethylene-α-olefin copolymer polymerized by a metallocene catalyst having a molecular weight ratio of not more than 3 ° C. and having a molecular weight ratio defined by a ratio of weight average molecular weight (Mw) / number average molecular weight (Mn) of not more than 3; Polyurethane resin, acrylic resin, polyvinyl chloride resin, ethylene vinyl acetate resin, polyester resin, butadiene resin, styrene resin that can be heat-sealed to a plastic carrier tape, or a combination thereof Wherein the conductive fine powder of any one of tin oxide and zinc oxide is dispersed in the adhesive, and the amount of the conductive fine powder is based on 100 parts by weight of the base resin of the adhesive. 10 to 1000 parts by weight, and the surface resistance of the adhesive layer is 1
0 ¹³ Ω / □ or less, and the adhesive strength between the adhesive layer of the cover tape and the sealing surface of the carrier tape is larger than the interlayer adhesive strength between the intermediate layer of the cover tape and the adhesive layer. The adhesive strength between layers is 10 to 130 gr per 1 mm of seal width, the total light transmittance of the cover tape is 70% or more, and the tensile impact strength is 400 kg-
cm / cm ² or more, a cover tape for embossed carrier tape for surface mounting, or a biaxially stretched film in which the outer layer is either polyester or polypropylene, and the second layer inside is a stretched or unstretched polypropylene or nylon. One of the layers of the stretched film, the inside of which is an intermediate layer and has a tear strength (JIS K 7128) of 100 kg
/ Cm, tensile impact strength (ASTM D 1822) 100k
g-cm / cm ² or more, cloudiness (JIS K 7105) is 15% or less, and resin density is 0.900 to 0.925 g / cm.
³ , the melting point is 110 ° C or less, and the weight average molecular weight (Mw)
An ethylene-α-olefin copolymer polymerized with a metallocene catalyst having a molecular weight ratio defined by a ratio of / number average molecular weight (Mn) of 3 or less, wherein an adhesive layer can be heat-sealed to a plastic carrier tape. Polyurethane resin, acrylic resin, polyvinyl chloride resin, ethylene vinyl acetate resin, polyester resin, butadiene resin, styrene resin, or any combination thereof, and the adhesive The conductive fine powder of any one of tin oxide and zinc oxide is dispersed therein, and the amount of the conductive fine powder added is equal to the base resin 100 of the adhesive.
10 to 1000 parts by weight with respect to parts by weight, the surface resistance of the adhesive layer is 10 ¹³ Ω / □ or less, and the adhesive strength between the adhesive layer of the cover tape and the sealing surface of the carrier tape is The interlayer adhesive strength between the intermediate layer and the adhesive layer is larger than the interlayer adhesive strength between the intermediate layer and the adhesive layer, and the interlayer adhesive strength between the intermediate layer and the adhesive layer is 10 to 130 gr per 1 mm of seal width, and the total light transmittance (JIS K 7105) of the cover tape is 70% or more, the tensile impact strength is 400 kg-cm / cm ² or more, and the resin of the ethylene-α-olefin copolymer in the intermediate layer in any of the constitutions uses zirconocene dichloride and methylaluminoxane as catalysts. A cover tape for an embossed carrier tape for surface mounting, which is characterized by being polymerized.

[0007]

FIG. 1 is a diagram showing components of a cover tape 1 according to the present invention.
2, the outer layer 2 in FIG. 1 is a biaxially stretched polyester film or a biaxially stretched polypropylene film, and has a thickness of 6 to 25 μm.
m is a film with good transparency, excellent heat resistance, and rigidity. When the outer layer is less than 6 μm, the rigidity is lost, and when it exceeds 25 μm, the outer layer is too hard and the seal becomes unstable. The mid layer 4 has a tear strength (JIS K 7128) of 100 kg / cm or more, a tensile impact strength (ASTM D 1822) of 100 kg-cm / cm ² or more, and a haze (JIS K 7105) of 15% or less. Density 0.990-0.925 g / cm ³ and melting point 110 ° C
Weight average molecular weight (Mw) / number average molecular weight (M
An ethylene-α-olefin copolymer polymerized with a metallocene catalyst having a molecular weight ratio (polydispersity) defined by the ratio n) of 3 or less. Tearing strength 100kg / cm
If the tensile strength is less than 100 kg-cm / cm, the impact force at the time of high-speed peeling cannot be sufficiently coped with, and there is a risk that the tape may break. On the other hand, if the haze exceeds 15%, the transparency of the entire cover tape is greatly reduced, and the visibility of the device is reduced. The density of the ethylene-α-olefin copolymer of the intermediate layer resin is 0.900 g.
/ Cm ^{3 is} less than 0.930.
If the ratio exceeds, the low-temperature sealing property deteriorates. The polydispersity is 3
Above, variations in the sealing property increase, causing stickiness and odor of the film and lowering the transparency, so that good characteristics cannot be obtained. In this case, the resin is most preferably a so-called metallocene catalyst polymerized with zirconocene dichloride and methylaluminoxane as catalysts.

The metallocene catalyst is called a single-site catalyst having a uniform active site and is distinguished from a multi-site catalyst such as a conventional Ziegler-Natta catalyst. In the case of a multi-site catalyst, it has various types of active sites and thus has a wide molecular weight distribution, and since the comonomer content differs for each molecule, it is badly affected by a wide distribution of properties such as low-temperature heat sealability and transparency. For example, LLDPE is capable of imparting tear resistance and tensile impact resistance to LDPE,
The low-temperature sealability and the transparency are deteriorated. On the other hand, single-site catalysts have a narrow molecular weight distribution due to uniform active sites,
Since the comonomer content of each molecule is almost equal, good low-temperature heat sealability and transparency can be obtained. Middle layer 4
The surfaces of the outer layer 2 and the outer layer 2 that are in contact with each other can be subjected to a surface treatment such as a corona treatment, a plasma treatment, or a sand blast treatment as needed to improve the adhesion, and can be bonded by dry lamination or extrusion lamination. The thickness of the intermediate layer is 10 μm or more, preferably a film of 20 to 60 μm. If it is thinner than 10 μm, there is no effect of tear resistance,
When the thickness is more than 60 μm, the heat sealing property is deteriorated. The adhesive layer 5 is a heat-seal lacquer-type thermoplastic adhesive of any one of polyurethane resin, acrylic resin, ethylene vinyl acetate resin, polyvinyl chloride resin, polyester, butadiene resin and styrene resin. Alternatively, it has a characteristic that it can be heat-sealed to a plastic carrier tape of a mating material by a combination thereof.

[0009] Further, conductive fine powder of either tin oxide or zinc oxide is uniformly dispersed in the adhesive.
The surface resistance of the adhesive layer after film formation is at least 10 ¹³ Ω / □
The following is necessary, and more preferably 10 ⁶ Ω / □ to 10
Good range of ¹⁰ Ω / □. If it exceeds 10 ¹³ Ω / □, the electrostatic effect becomes extremely poor and the desired performance cannot be obtained. Further, the addition amount is 10 to 1000 parts by weight, more preferably 100 to 300 parts by weight, based on 100 parts by weight of the base resin of the adhesive, depending on the surface resistance characteristics.
If the amount is less than 10 parts by weight, the antistatic effect is not exhibited, and
If the amount is more than 00 parts by weight, the dispersibility in the adhesive becomes extremely poor, which is not suitable for production. In addition, since the electrostatic treatment material itself has conductivity, it has a semi-permanent electrostatic effect, does not cause bleeding and the like, and does not affect the sealing property. The surface resistance value of the adhesive layer is 10 ¹³ Ω / □ or less. Therefore, even when the electronic component comes into contact with the cover tape during the transportation of the electronic component encapsulated in the carrier tape with the cover tape, or when the electronic component is picked up by peeling off the cover tape. Also, no static electricity is generated, and the electronic components can be protected from static electricity. In order to further enhance the electrostatic effect, an antistatic treatment layer or a conductive layer may be provided on the outer layer side, that is, on the front and back surfaces of the biaxially stretched film. The method of forming the heat-sealable adhesive may be either a melt film forming method or a solution film forming method, but is preferably a solution film forming method from the viewpoint of dispersibility of the conductive fine powder.

In the sealing and peeling process of the cover tape, first, the cover tape 1 is attached to the carrier tape 6.
On both sides, one side is continuously sealed in a rail shape with a width of about 1 mm. (FIG. 3) Next, when peeling the cover tape 1 from the carrier tape 6 at the time of peeling, the adhesive strength between the adhesive layer 5 of the cover tape 1 and the sealing surface of the carrier tape 6 is determined by the intermediate layer 4 of the cover tape 1. When the peel strength is smaller than the interlayer adhesion strength between the adhesive layer 5 and the adhesive layer 5, the peel-off strength corresponds to the adhesive strength between the adhesive layer 5 of the cover tape 1 and the sealing surface of the carrier tape 6. Causes a peel. On the other hand, when the adhesive strength between the adhesive layer 5 of the cover tape 1 and the sealing surface of the carrier tape 6 is larger than the interlayer adhesive strength between the intermediate layer 4 and the adhesive layer 5 of the cover tape 1 as in the present invention, the film is formed. Only the sealed portion of the adhered adhesive layer 5 remains on the carrier tape (FIG. 4), and the cover tape after peeling off (FIG. 5) has a shape in which only the heat-sealed portion of the adhesive layer 5 has fallen off. Peeling is carried out by peeling or peeling. That is, the peel-off strength corresponds to the interlayer adhesion strength between the adhesive layer 5 and the intermediate layer 4, the release surface is designed in the cover tape, and the interlayer adhesion strength is set regardless of the material of the carrier tape. Therefore, a stable peel-off strength can be obtained without being affected by the sealing state of the cover tape and the carrier tape. In this case, the interlayer adhesion strength between the intermediate layer and the adhesive layer of the cover tape is 10 to 130 per 1 mm of the seal width.
gr More preferably, the adhesive is selected to be 10 to 70 gr. If the peel strength is lower than 10 gr, there is a problem that the cover tape comes off when the package is transported, and the electronic components as contents fall off. Conversely, if it is higher than 130 gr, the carrier tape will vibrate when the cover tape is peeled off, causing a phenomenon of jumping out of the storage pocket immediately before mounting the electronic component, that is, a jumping trouble. According to this transfer peeling mechanism, it is possible to obtain the desired performance in which the dependency on the sealing condition is lower than in the conventional interface peeling and the peel-off strength due to the storage environment does not change with time. Also, since the cover tape is configured so that the total light transmittance is 70% or more, preferably 80% or more, the internal electronic components sealed in the carrier tape can be visually or mechanically confirmed. If it is lower than 70%, it is difficult to confirm the internal electronic components.

Next, in FIG. 2, a stretched or unstretched film of polypropylene or nylon is used as the outer layer 2 and the second layer 3 inside the outer layer 2. The transparent layer has a thickness of 6 to 50 μm and is excellent in impact resistance and tear resistance. Film. When the thickness of the layer 3 is less than 6 μm, the tear resistance is insufficient, and when it exceeds 50 μm, the sealing property becomes unstable. By the way, there is a biaxially stretched nylon film as a film having excellent transparency, heat resistance, tear resistance, and impact resistance. However, when it is used as an outer layer, it has poor slipperiness with a heat seal iron, and especially a sliding seal. Not suitable for machines. In addition, if the outer layer is used because of its high hygroscopicity, the problem of blocking occurs, so that it is not suitable for the outer layer. The sides of the outer layer 2 and the layer 3 that are in contact with each other can be subjected to a surface treatment such as a corona treatment, a plasma treatment, or a sand blast treatment as necessary to improve the adhesion, and can be bonded by extrusion lamination, dry lamination, or the like.
The intermediate layer 4 and the adhesive layer 5 have the same structure as in FIG.

[0012]

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited by these examples. << Examples 1 to 7 and Comparative Examples 1 to 5 >> A biaxially stretched film as an outer layer as shown in Tables 1 and 2 and a laminate in which an intermediate layer is laminated inside, and between the outer layer and the intermediate layer. Further, a stretched or unstretched film having excellent tear resistance and impact resistance was laminated. An adhesive layer was formed into a solution having a thickness of 2 μm by a roll coater on the side opposite to the outer layer of the intermediate layer or the side in contact with the layer having excellent tear resistance and impact resistance. The density, melting point, tear strength, tensile impact strength and haze of the resin in the intermediate layer are shown in Table 1.
And Table 2 together. The type and amount of the conductive fine powder are shown in parentheses after the adhesive layer. The amount added is an amount (parts by weight) based on 100 parts by weight of the thermoplastic resin of the adhesive layer.
After slitting the obtained prototype to 13.5mm width, 1
Heat sealing was performed with a 6 mm wide polystyrene carrier tape, the presence or absence of tape breakage was determined by a high-speed peeling machine (42000 mm / min), and the peel strength was measured (measurement speed:
300mm / min). Further, the surface resistance value on the adhesive layer side, the visible light transmittance of the prototype cover tape, and the tensile impact strength were measured, and the results are shown in Tables 3 and 4. Heat sealing ^{conditions: 120 ℃ / 1kg / cm 2} / 1sec, sliding seals, seal width 1 mm × 2 Peel conditions: 180 ° Peel, Peel Speed 300 mm / mi
n, number of samples: 3

The raw materials used are as follows.・ PE: Polyethylene using metallocene catalyst for polymerization ・ PET: Polyethylene terephthalate (unstretched) ・ O-PET: Biaxially stretched polyethylene terephthalate ・ PP: Polypropylene (unstretched) ・ OPP: Biaxially stretched polypropylene ・ NY: Nylon (Unstretched) ・ ONY: Biaxially stretched nylon ・ EVA: Ethylene vinyl acetate copolymer ・ PVC: Polyvinyl chloride ・ LDPE: Low density polyethylene ・ LLDPE: Linear low density polyethylene ・ SnO ₂ : Tin oxide ・ ZnO ₂ ： Zinc oxide

Table 1 Example 1 2 3 4 5 6・ Outer layer Resin used O-PET O-PET O-PET OPP O-PET OPP thickness (μm) 25 12 9 16 12 25・ Second layer Resin used-ONY PP NY OPP- Thickness (μm) 12 15 15 15・ Intermediate layer Resin used PE PE PE PE PE PE PE Thickness (μm) 20 30 50 15 40 30 Density (g / cm ³ ) 0.905 0.905 0.910 0.920 0.915 0.905 Melting point (° C) 90 88 100 105 103 93 Tear strength (kg / cm) 124 145 120 110 130 145 Tensile impact strength 120 125 110 105 107 112 (kg-cm / cm ² ) Haze (%) 8 7 13 12 13 10・ Adhesive layer Adhesive used PVC-based Acrylic-based PET-based Polyurethane-based EVA-based phthalocyanine-based conductive fine powder SnO ₂ SnO ₂ ZnO ₂ ZnO ₂ SnO ₂ SnO ₂ (parts by weight) 150 250 320 600 900 200

Table 2 Example Comparison Example 7 1 2 3 4 5 · Outer layer Resin used O-PET O-PET OPP O-PET OPP O-PET thickness (μm) 16 25 25 16 25 16 · Second layer Resin used ONY − − OPP − ONY thickness (μm) 12 15 12・ Intermediate layer Resin PE LLDPE − 5% EVA LLDPE LDPE Thickness (μm) 40 30 30 20 40 Density (g / cm ³ ) 0.910 0.908 0.933 0.915 0.919 Melting point (° C) ) 102 120 125 125, 128 Tear strength (kg / cm) 124 85 45 105 60 Tensile impact strength 120 75 35 100 45 (kg-cm / cm ² ) Haze (%) 11 20 13 18 8 ・ Adhesive layer Adhesive used Styrene PET Polyurethane EVA Acrylic EVA conductive fine powder SnO ₂ ZnO ₂ SnO ₂ SnO ₂ Surfactant SnO ₂ (parts by weight) 400 150 7 1200 2 1500

Table 3 Example 1 2 3 4 5 6 High-speed peeling test table None None None None None None None Peel strength Initial value 40 45 30 25 43 52 40 ° C-90%, 30 days 55 45 28 62 38 38 55 60 ° C, 30 days 68 50 55 75 80 68 Adhesive layer peeling method Transfer Transfer Transfer Transfer Transfer Transfer Transfer Tensile impact strength 420 505 350 220 430 450 (kg-cm / cm ² ) Surface resistance (Ω / □) 10 ⁹ 10 ⁸ 10 ⁶ 10 ⁷ 10 ⁵ 10 ⁸ Total light transmittance (%) 88.0 85.2 76.3 50.7 25.8 81.0

Table 4 Example Comparison example 7 1 2 3 4 5 High-speed peeling test test piece No Yes Yes No Yes No No Peel strength Initial value 25 10 45 5 35 11 40 ° C-90%, 30 days 30 5 15 0 5 2 60 ° C, 30 days 45 48 150 10 25 15 Adhesive layer peeling method Transfer Transfer Interface Transfer Transfer Transfer Tensile impact strength 505 350 220 430 280 550 (kg-cm / cm ² ) Surface resistance (Ω / □) 10 ⁷ 10 ¹² 10 ¹⁴ 10 ⁴ 10 ¹⁴ 10 ⁴ Total light transmittance (%) 74.3 72.6 89.5 45.6 88.0 30.5

[0018]

By using the cover tape of the present invention, there is no danger of a tape breakage problem even if the speed of the mounting machine is increased, and the adhesive layer is electrostatically treated. The point that static electricity generated at the time of contact with the tape or peeling of the cover tape is suppressed, and it does not affect the sealability, it is possible to seal at low temperature by combining the heat seal lacquer adhesive and the intermediate layer, Peel-off strength can be arbitrarily set in the range of 10 to 120 gr per 1 mm.Because the peel-off strength is determined by the adhesion strength between the layers in the cover tape, it is not affected by the sealing conditions with the carrier tape, Inspection of devices with good transparency and contents is easy,
These five points solve the conventional problems of tape breakage during peeling, as well as the problem that the peel-off strength greatly depends on the sealing conditions, the problem that changes over time due to the storage environment, and the It can solve the problem of static electricity that occurs when parts and cover tape come into contact or peel off the cover tape.
A stable peel-off strength can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a layer structure of a cover tape of the present invention.

FIG. 2 is a sectional view showing a layer structure of a cover tape of the present invention.

FIG. 3 is a cross-sectional view showing a use state in which the cover tape of the present invention is adhered to a carrier tape.

FIG. 4 is a cross-sectional view of the cover tape of the present invention showing a state where the cover tape is peeled off from the carrier tape.

FIG. 5 is a cross-sectional view of the carrier tape showing a state where the cover tape of the present invention is peeled off.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65D 85/86 B32B 27/00 B32B 27/28 H01L 21/68

Claims (3)

(57) [Claims] 1. A cover tape which can be heat-sealed to a plastic carrier tape in which storage pockets for accommodating chip-type electronic components are continuously formed, wherein the cover tape has an outer layer of either polyester or polypropylene. It is a biaxially stretched film, and the middle layer has tear strength (JIS
K 7128) is 100 kg / cm or more, and the tensile impact strength (ASTM
D 1822) is 100 kg-cm / cm ² or more, cloudiness (JIS
K 7105) is 15% or less of an ethylene-α-olefin copolymer,
Density 0.990-0.925 g / cm ³ and melting point 110
° C or lower and weight average molecular weight (Mw) / number average molecular weight
The ratio of molecular weight (polydispersity) defined by the ratio of (Mn) is 3
Hereinafter, and the polyurethane-based resin adhesive layer may be heat sealed to a plastic carrier tape, an acrylic resin,
Polyvinyl chloride-based resin, ethylene vinyl acetate-based resin, polyester-based resin, butadiene-based resin, styrene-based resin, or an adhesive based on a combination thereof, tin oxide, zinc oxide in the adhesive Any of the conductive fine powders is dispersed, and the amount of the conductive fine powder added is 10 to 1 with respect to 100 parts by weight of the base resin of the adhesive.
000 parts by weight, and the surface resistance of the adhesive layer is 10 ¹³ Ω /
□ The adhesive strength between the adhesive layer of the cover tape and the sealing surface of the carrier tape is larger than the adhesive strength of the interlayer between the intermediate layer and the adhesive layer of the cover tape. Strength is 10 to 1 mm per seal width
130 gr, and the total light transmittance of the cover tape is 7
0% or more, and the tensile impact strength is 400 kg-cm / c
m ² or more at a surface mount embossed carrier tape cover tape. 2. A cover tape which can be heat-sealed to a plastic carrier tape in which storage pockets for accommodating chip-type electronic components are continuously formed, wherein the cover tape has an outer layer made of either polyester or polypropylene. A biaxially stretched film, the second inner layer of which is either a stretched or unstretched film of polypropylene or nylon, and the inner middle layer has a tear strength (JIS K 7128) of 100 kg / cm or more. tensile impact strength (ASTM D 1822) is 100kg-cm / cm ² or more, an ethylene -α-olefin copolymer is haze (JIS K 7105) is 15% or less, ethylene -α-olefin copolymerization
The density of the coalesced is between 0.900 and 0.925 g / cm ³ and the melting point is
110 ° C. or less, weight average molecular weight (Mw) / number average minute
Of molecular weight (polydispersity) defined by the ratio of molecular weight (Mn)
Is 3 or less, and an adhesive layer of a polyurethane resin, an acrylic resin, a polyvinyl chloride resin, an ethylene vinyl acetate resin, a polyester resin, a butadiene resin, and a styrene resin which can be heat-sealed to a plastic carrier tape. An adhesive according to any one of these, or a combination of these, in which conductive fine powder of tin oxide or zinc oxide is dispersed in the adhesive, and the amount of the conductive fine powder added is 1 for 100 parts by weight of base resin
0 to 1000 parts by weight, and the surface resistance of the adhesive layer is 10
¹³ Ω / □ or less, and the adhesive strength between the adhesive layer of the cover tape and the sealing surface of the carrier tape is larger than the interlayer adhesive strength between the intermediate layer and the adhesive layer of the cover tape. And the interlayer adhesion strength is 10 to 130 gr per 1 mm of seal width, the total light transmittance of the cover tape is 70% or more, and the tensile impact strength is 400 kg-c.
m / cm ² or more cover tape for embossed carrier tape for surface mounting. 3. The cover for an embossed carrier tape for surface mounting according to claim 1, wherein the ethylene-α-olefin copolymer resin of the intermediate layer is polymerized using zirconocene dichloride and methylaluminoxane as catalysts. tape.