JP5456602B2 - Cover tape, cover tape manufacturing method, and electronic component package - Google Patents

Description

  The present invention relates to a cover tape, a method for manufacturing the cover tape, and an electronic component package.

  Conventionally, as a method for transporting electronic components, a taping reel method in which the electronic components are sealed in a packaging material and transported is known. In this taping reel method, electronic components are inserted into a carrier tape having pockets for storing electronic components at regular intervals along the length of the tape, and then the cover tape is heat sealed from above to seal the electronic components. This is a method of winding and storing and transporting the tape in a reel shape.

  The package wound in a reel shape is transported to the mounting machine manufacturer, and in the manufacturing process of circuit boards, the cover tape is peeled off from the carrier tape, and the stored electronic components are sucked by the air suction nozzle, and the circuit Mounted on the board.

  As a cover tape used as a packaging material for electronic components, for example, Patent Document 1 describes a cover tape for packaging electronic components using a biaxially stretched film of polyester, polypropylene, nylon, or the like as a base material layer. . Patent Document 2 includes a base material layer, an intermediate layer, and a sealant layer, the intermediate layer has a specific heat shrinkability, and the base material layer and the intermediate layer have a specific thickness. A tape is disclosed.

JP 2006-312489 A JP 2010-76832 A

  However, when the cover tape for packaging electronic components described in Patent Document 1 is heat-sealed to a carrier tape, there is a problem that the cover tape is loosened.

  Moreover, in the cover tape of patent document 2, the slack of the cover tape after heat sealing is achieved by using an intermediate layer having a specific heat shrinkage and setting the base material layer and the intermediate layer to a specific thickness. Trying to reduce. However, even the cover tape described in Patent Document 2 cannot be said to sufficiently reduce the slack that occurs after heat sealing.

  This invention is made | formed in view of the said situation, and it aims at providing the cover tape which can fully reduce the slack which arises after heat-sealing to a carrier tape. Moreover, an object of this invention is to provide the manufacturing method for manufacturing the said cover tape, and the electronic component package using the said cover tape.

  That is, in the present invention, at least one of a flow direction (hereinafter, sometimes referred to as “MD”) and a width direction perpendicular to the flow direction (hereinafter, sometimes referred to as “TD”) between 80-200 ° C. Provided is a cover tape having a temperature at which the thermal shrinkage is 5% or more in the direction.

  The cover tape which concerns on this invention can fully reduce the looseness after the heat seal which had arisen with the conventional cover tape by having the said structure. That is, according to the cover tape according to the present invention, tight taping without slack is possible even after heat sealing to the carrier tape.

The cover tape according to the present invention preferably has a temperature T ₁ and a temperature T ₂ that satisfy the following formulas (i), (ii), and (iii).
0 ° C. <T ₁ −T ₂ ≦ 60 ° C. (i)
S ₁ -S ₂ ≧ 20% (ii)
80 ° C. ≦ T ₁ ≦ 200 ° C. (iii)
60 ° C. ≦ T ₂ (iv)
[Wherein, S ₁ represents the heat shrinkage rate (%) at the temperature T ₁ , and S ₂ represents the heat shrinkage rate S ₂ (%) at the temperature T ₂ . ]

  According to the cover tape having the above configuration, the slackness after heat sealing can be further reduced, and the dimensional change before and after heat sealing is sufficiently suppressed. That is, according to the cover tape having the above-described configuration, it is possible to simultaneously achieve reduction of slackness after heat sealing and suppression of dimensional change.

  The reason for the above effect is not necessarily clear, but is considered as follows. That is, in the taping reel method, the cover tape is disposed so as to cover the pocket for storing the electronic component of the carrier tape, and is heat-pressed and heat-sealed by a heat sealing iron at both edges in the width direction of the pocket. .

Here, the cover tape inevitably heats not only the heated portion with which the heat sealing iron is in direct contact, but also the surroundings (for example, the location located above the electronic component storage pocket). For example, when the temperature of the iron for heat sealing was T _1, the surrounding is thought to be heated to a lower than T ₁ temperature (e.g. T _2). At this time, for example, in the cover tape described in Patent Document 2, there is a possibility that a dimensional change occurs as a whole of the cover tape because the heated portion and other portions are subjected to the same degree of thermal contraction.

On the other hand, according to the cover tape having the above-described structure, since the heat shrinkage rate is sufficient at the temperature (for example, T ₁ ) applied to the heated portion, the slackness after the heat sealing is sufficiently reduced. On the other hand, as shown in the above formula (ii), there is a difference of 20% or more between the thermal shrinkage rate at T _{1 and} the thermal shrinkage rate at T ₂ . It is considered that the dimensional change of the entire cover tape is suppressed.

  The cover tape which concerns on this invention shall be equipped with a base material layer, a sealing layer, and the intermediate | middle layer arrange | positioned between this base material layer and this sealing layer, for example.

  In this case, in the cover tape according to the present invention, the intermediate layer preferably contains a resin composition containing a polyolefin resin, and the gel fraction of the resin composition is more preferably 5 to 80% by mass.

  In the cover tape of the present invention, the intermediate layer is considered to function as a cushion layer that uniformly disperses the pressurization when heated and pressed with a heat sealing iron. When such an intermediate layer has the above-described configuration, the peel strength between the cover tape and the carrier tape is further stabilized. Further, according to the cover tape having the above-described configuration, it is possible to further suppress the occurrence of lifting at the end portion in the width direction of the cover tape due to the sufficiently suppressed flow of the intermediate layer. Become.

Here, the “gel fraction” indicates a value measured by the following method. That is, after measuring the initial mass of the sample to be measured, the sample is immersed in boiling paraxylene for 12 hours, the insoluble matter is extracted, and the mass of the insoluble matter after drying is measured. Then, the value calculated by the following formula is defined as “gel fraction”.
Gel fraction (mass%) = (mass of insoluble matter / initial mass of sample to be measured) × 100

  In the cover tape according to the present invention, the thickness of the seal layer is preferably 0.5 to 15% of the total thickness of the cover tape.

  The cover tape having the seal layer thickness within the above range is more excellent in adhesion to the carrier tape and has higher rigidity. According to the cover tape having such a high rigidity, the swing of the packaged electronic component can be further suppressed.

In the cover tape according to the present invention, the surface specific resistance value of the seal layer is preferably 1 × 10 ⁴ to 1 × 10 ¹³ Ω. According to such a cover tape, it is possible to suppress generation of static electricity when the cover tape after heat sealing is peeled off from the carrier tape.

  The present invention also provides a method for manufacturing a cover tape for manufacturing the cover tape described above. The method for producing a cover tape according to the present invention includes at least a first layer structure including a resin composition constituting the base material layer and a second layer structure including a resin composition constituting the intermediate layer. A step of heat-stretching the laminated body.

  According to the method for manufacturing a cover tape according to the present invention, the above-described cover tape can be easily manufactured.

  The present invention also provides an electronic component package using the cover tape according to the present invention.

  According to the electronic component package according to the present invention, since the cover tape according to the present invention is used, tight taping is applied, and the electronic component is prevented from swinging during the transportation of the electronic component package. be able to.

  ADVANTAGE OF THE INVENTION According to this invention, the cover tape which can fully reduce the slack which arises after heat-sealing to a carrier tape can be provided. Moreover, according to this invention, the electronic component package using the manufacturing method for manufacturing the said cover tape and the said cover tape can be provided.

It is a model perspective view which shows suitable one Embodiment of the cover tape of this invention. It is a model top view which shows the carrier tape in which the electronic component was inserted. It is a model top view which shows suitable one Embodiment of the electronic component package of this invention. It is a schematic cross section which shows suitable one Embodiment of the manufacturing method of an electronic component package.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, In the range of the summary, various deformation | transformation can be implemented.

  FIG. 1 is a schematic perspective view showing a preferred embodiment of the cover tape of the present invention. A cover tape 10 illustrated in FIG. 1 includes a seal layer 1, a base material layer 2, and an intermediate layer 3 disposed between the seal layer 1 and the base material layer 2. The cover tape 10 has a temperature at which the heat shrinkage rate is 5% or more in at least one of the flow direction (MD) and the width direction (TD) perpendicular to the flow direction between 80 and 200 ° C. In FIG. 1, the intermediate layer 3 has a single layer structure, but the intermediate layer 3 may have a multilayer structure.

  The cover tape 10 according to the present embodiment can sufficiently reduce the slackness after heat sealing that has occurred in the conventional cover tape by having the above-described configuration. That is, according to the cover tape 10 according to the present embodiment, tight taping without slack is possible even after heat sealing to the carrier tape.

  The cover tape according to the present embodiment is used, for example, as a cover tape for packaging electronic parts in the taping reel system described above. FIG. 2 is a schematic top view showing a carrier tape having an electronic component inserted, which is used in the taping reel system. The carrier tape 20 is provided with electronic component storage pockets 21 at regular intervals in the length direction A of the carrier tape 20. An electronic component 30 is inserted into the pocket 21.

  FIG. 3 is a schematic top view showing an electronic component package formed by heat-sealing the cover tape from the top of the carrier tape shown in FIG. 2 to seal the electronic component. In the electronic component package 11, the cover tape 10 is heat-sealed on the top of the carrier tape 20 in which the electronic component 30 is inserted. Since such an electronic component package 11 is in a tape shape, it can be wound and stored and transported in a reel shape.

  The electronic component package 11 wound in a reel shape is transported to a mounting machine manufacturer or the like, and in the manufacturing process of a circuit board or the like, the cover tape 10 is peeled off from the carrier tape 20, and the stored electronic component 30 is air. It is sucked by a suction nozzle and mounted on a circuit board.

  FIG. 4 is a schematic cross-sectional view showing an embodiment of a method for manufacturing an electronic component package. 4A is a schematic cross-sectional view of the carrier tape 20 shown in FIG. 2, and an electronic component 30 is inserted into an electronic component storage pocket 21 provided in the carrier tape 20.

  In the method of manufacturing an electronic component package according to the present embodiment, first, as shown in FIG. 4B, the cover tape 10 covers the electronic component storage pocket 21 of the carrier tape 20 in which the electronic component 30 is inserted. Arrange so that. Here, the cover tape 10 is disposed so that the surface of the carrier tape 20 on which the electronic component storage pocket 21 is formed and the seal layer 1 face each other.

  Next, as shown in FIG. 4C, the cover tape 10 is heated and pressed by the heat sealing iron 50 at both edges in the width direction (B direction in FIG. 2) of the electronic component storage pocket 21. Here, the heating temperature of the heat sealing iron 50 is preferably a temperature at which the thermal shrinkage rate in at least one direction of the MD and TD of the cover tape 10 is 5% or more. By heat-sealing at such a temperature, the slack of the cover tape 10 is further reduced.

  FIG.4 (d) is a schematic cross section which shows the electronic component package manufactured by the manufacturing method of the electronic component package which concerns on this embodiment. The electronic component package 11 is tightly taped with the cover tape 10 without slack. Therefore, the electronic component 30 stored in the electronic component package 11 moves out of the electronic component storage pocket 21 due to vibration during transportation, or excessively swings in the electronic component storage pocket 21. Without being held in the electronic component package 11 stably.

  Hereinafter, the cover tape 10 according to the present embodiment will be described in detail.

  The cover tape 10 used for the electronic component package 11 preferably has the following characteristics, for example. That is, (1) having good adhesive strength to the carrier tape 20, (2) stable peeling when peeling from the carrier tape, and (3) occurring when peeling from the carrier tape It is excellent in so-called antistatic property that suppresses the electronic component 30 from jumping out of the electronic component storage pocket 21 due to peeling electrification, and (4) transfer of the electronic component 30 from the electronic component storage pocket 21 during transportation. In addition, in order to prevent damage to the electronic component 30 due to vibration during transportation, it is preferable that the electronic component 30 has a property of being excellent in position control.

  However, in the conventional cover tape, loosening is likely to occur after heat sealing, and (1) an unnecessary space is formed above the electronic component storage pocket 31. (2) The carrier between the electronic component storage pockets 31 is formed. There is a problem that a gap is formed between the tape 20 and the cover tape. According to the problem (1), the electronic component 30 may swing unnecessarily in the electronic component storage pocket 21 and may be damaged. Further, according to the above problem (2), the electronic component 30 may be transferred from the electronic component storage pocket 21 during transportation to the gap between the carrier tape 20 and the cover tape.

  On the other hand, the cover tape 10 according to this embodiment can sufficiently reduce the slackness after heat sealing that has occurred in the conventional cover tape by having the above-described configuration. That is, according to the cover tape 10 according to the present embodiment, tight taping is possible without sagging even after heat sealing to the carrier tape 20. Therefore, the electronic component package 11 using the cover tape 10 is excellent in position regulation of the electronic component 30.

  The cover tape 10 according to the present embodiment has a heat shrinkage rate of preferably 5 to 90%, more preferably 7 to 85%, and still more preferably 8 in at least one direction of MD and TD between 80 and 200 ° C. Having a temperature of ~ 80%. According to such a cover tape 10, by performing heat sealing at a temperature at which the thermal shrinkage rate falls within the above range, taping with further reduced slack is possible.

The cover tape 10 according to the present embodiment preferably has a temperature T ₁ (° C.) and a temperature T ₂ (° C.) satisfying the following formulas (i) and (ii) in at least one direction of MD and TD. . In the formula, S ₁ represents the heat shrinkage rate (%) at the temperature T ₁ , and S ₂ represents the heat shrinkage rate S ₂ (%) at the temperature T ₂ .
0 ° C. <T ₁ −T ₂ ≦ 60 ° C. (i)
S ₁ -S ₂ ≧ 20% (ii)
80 ° C. ≦ T ₁ ≦ 200 ° C. (iii)
60 ° C. ≦ T ₂ (iv)

Thus, for example the cover tape 10, at least one direction of MD and TD, the heat shrinkage at 140 ℃ _{(S 1)} and the thermal shrinkage at 80 ° C. The difference between _{(S 2) (S 1 -S} 2) is 20 % Or more is preferable.

  According to such a cover tape 10, the slackness after heat sealing can be further reduced, and the dimensional change before and after heat sealing is sufficiently suppressed. That is, according to the cover tape 10 having the above-described configuration, it is possible to simultaneously achieve reduction of slackness after heat sealing and suppression of dimensional change.

  The reason for the above effect is not necessarily clear, but is considered as follows. That is, when being heated and pressurized by the heat sealing iron 50, the cover tape 10 is not only heated but directly contacted by the heat sealing iron 50, and the periphery thereof (for example, the upper part of the electronic component storage pocket 21). ) Is inevitably heated. The temperature applied at this time is different between the heated part and its surroundings. Here, for example, in the conventional cover tape, since the difference in thermal shrinkage due to temperature is small, there is a possibility that the heated portion and its surroundings will have the same degree of thermal shrinkage and the entire cover tape may change in dimensions. is there.

On the other hand, according to the cover tape 10 having the above-described configuration, since the heat shrinkage rate is sufficient at the temperature (for example, T ₁ ) applied to the heated portion, the slackness after the heat sealing is sufficiently reduced. On the other hand, since the thermal shrinkage rate at the temperature (for example, T ₂ ) around the heated part is low around the heated part, the thermal shrinkage is suppressed as compared with the heated part. It is considered that the dimensional change of the entire cover tape 10 can be suppressed by suppressing the heat shrinkage around the heated portion.

  Here, the thermal contraction rate at a predetermined temperature is determined by the following method. First, a film sample obtained by cutting the cover tape 10 into a 100 mm square is placed in an air oven thermostat set to a predetermined temperature, heated for 10 minutes in a freely contracted state, and then center points of sides facing each other with respect to MD and TD. The distance between the films is measured to determine the amount of shrinkage of the film, and the percentage of the value divided by the original dimension (the distance between the center points of the facing sides before the heat treatment) is calculated. Then, this is repeated twice, and for each of MD and TD, an arithmetic average value of the measurement results of the two times is calculated, and this arithmetic average value is set as a thermal shrinkage rate at a predetermined temperature of each of MD and TD.

  Moreover, the slack of the cover tape is measured by the following method, for example. That is, the displacement of MD and TD of the cover tape 10 after heat sealing is measured with a laser microscope. The displacement difference of the cover tape 10 between MD and TD is preferably 100 μm or less, more preferably 70 μm or less, and further preferably 50 μm or less. When the displacement difference between MD and TD is 100 μm or less, the cover tape 10 is less slack, the gap between the carrier tape 20 and the cover tape 10 is small, and the electronic component 30 can be prevented from being damaged due to vibration during transportation. In addition, it is preferable in that the electronic component 30 can be prevented from transferring from the electronic component storage pocket 21.

  The cover tape 10 preferably has a thermal shrinkage rate at 60 ° C. of 5% or less in at least one direction of MD and TD. Moreover, as for the cover tape 10, it is more preferable that the thermal contraction rate in 60 degreeC is 5% or less in any direction of MD and TD. Such a cover tape is excellent in storage stability because the dimensional change of the cover tape during storage is suppressed.

The surface specific resistance value of the seal layer 1 of the cover tape 10 is preferably 1 × 10 ⁴ to 1 × 10 ¹³ Ω, and more preferably 1 × 10 ⁷ to 1 × 10 ¹¹ Ω. When the surface specific resistance value of the sealing layer 1 is 1 × 10 ¹³ Ω or less, the electronic component 30 is sufficiently prevented from jumping out of the electronic component storage pocket 21 due to peeling electrification generated when peeling from the carrier tape. Can do.

  The peel strength of the cover tape 10 is preferably 10 to 130 g, more preferably 20 to 100 g. When the peel strength is 10 g or more, the cover tape 10 becomes difficult to peel from the carrier tape 20 due to vibration during transportation or storage, and loss of the packaged electronic component 30 can be prevented. Further, when the peel strength is 130 g or less, problems such as breakage of the cover tape 10 at the time of peeling are reduced.

  The thickness of the cover tape 10 is preferably 10 to 100 μm, more preferably 20 to 90 μm. If the thickness of the cover tape is 10 μm or more, it is preferable in that the running property of the tape in a taping machine is stable. If the thickness of the cover tape is 100 μm or less, a stable peel strength can be easily obtained during heat sealing. preferable.

  In FIG. 1 and the like, the cover tape 10 has been described as having one each of the sealing layer 1, the base material layer 2, and the intermediate layer 3. However, the cover tape of the present invention is not limited to such a form. . The cover tape of the present invention can include a plurality of seal layers, can include a plurality of base material layers, and can include a plurality of intermediate layers. For example, the cover tape of the present invention may be laminated in the order of base material layer / intermediate layer / base material layer / seal layer. Moreover, the cover tape of this invention may further be provided with layers other than a seal layer, a base material layer, and an intermediate | middle layer.

  Next, each layer constituting the cover tape 10 will be described in detail.

[Seal layer 1]
The seal layer 1 is a layer constituting an adhesive surface with a packaged body such as a carrier tape.

  Examples of the sealing layer 1 include a layer made of a base resin, a layer made of a tackifier and a base resin, and the like. In addition, when the sealing layer 1 contains a tackifier, the cover tape 10 is preferable in that the sealing property is improved and the adhesive tape has better adhesive strength to a packaged object such as a carrier tape.

  Examples of tackifiers include rosin resins, terpene resins, petroleum resins, styrene resins, and coumarone / indene resins. These tackifiers are preferably selected from the viewpoints of the composition and tackiness of the seal layer, tackiness, and holding power. In addition, these tackifiers can be used individually by 1 type or in combination of 2 or more types.

  A rosin resin is preferable because it has a small average molecular weight, a sharp molecular weight distribution, and a wide range of compatibility with a base resin described later. Examples of the rosin resin include rosin esters.

  Terpene resins are preferred because they have good compatibility, easily provide a balance of adhesive properties over a wide resin concentration range, and have adhesive properties at low temperatures and release imparting properties. Examples of the terpene resin include terpene resins, terpene hydrogenated resins, terpene phenol copolymers, and the like.

  Examples of petroleum resins include aromatic petroleum resins, alicyclic petroleum resins, hydrogenated petroleum resins, and the like. The hydrogenated petroleum resin can be produced, for example, by hydrogenating a specific aliphatic resin, an aromatic resin, a copolymer thereof, and an aromatic resin. The alicyclic hydrogenated petroleum resin is particularly preferable because it is excellent in thermal stability and the compatibility with other resins can be easily adjusted depending on the degree of hydrogenation.

  Examples of the base resin include ethylene-vinyl acetate copolymers, ethylene-aliphatic unsaturated carboxylic acid copolymers and ethylene-aliphatic unsaturated carboxylic acid ester copolymers, polyolefin resins, and mixtures thereof. It is done.

  Among them, the base resin is at least one selected from an ethylene-vinyl acetate copolymer (EVA), an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene-aliphatic unsaturated carboxylic acid ester copolymer, and a polyolefin resin. It is preferable to include a kind of resin. When the sealing layer 1 contains such a resin, the sealing property of the cover film is improved and the adhesive layer has a good adhesive strength with respect to a packaged object such as a carrier tape.

  Here, the ethylene-vinyl acetate copolymer refers to a copolymer obtained by copolymerization of an ethylene monomer and vinyl acetate. The ethylene-aliphatic unsaturated carboxylic acid copolymer refers to a copolymer obtained by copolymerization of an ethylene monomer and at least one monomer selected from aliphatic unsaturated carboxylic acids. Furthermore, the ethylene-aliphatic unsaturated carboxylic acid ester copolymer refers to a copolymer obtained by copolymerization of an ethylene monomer and at least one monomer selected from an aliphatic unsaturated carboxylic acid ester.

  The copolymerization can be performed by a method such as a high pressure method or a melting method. In addition, as a catalyst of a copolymerization reaction, a multi-site catalyst and a single site catalyst can be used, for example. In the above copolymer, the bonding form of each monomer is not particularly limited, and a polymer having a bonding form such as a random bond or a block bond can be used. From the viewpoint of optical properties, the copolymer is preferably a copolymer polymerized using a high-pressure method and having a random bond.

  In the ethylene-vinyl acetate copolymer, the ratio of vinyl acetate in all monomers constituting the copolymer is preferably 10 to 40% by mass from the viewpoint of optical properties and adhesiveness, and 13 to 35% by mass. %, More preferably 15 to 30% by mass. From the viewpoint of extrusion processability, the melt flow rate value measured in accordance with JIS-K-7210 (hereinafter sometimes referred to as “MFR”) (190 ° C., 2.16 kg) is 0.3 g. It is preferably ˜30 g, more preferably 0.5 g to 30 g, and still more preferably 0.8 g to 25 g.

  Examples of the ethylene-aliphatic unsaturated carboxylic acid copolymer include an ethylene-acrylic acid copolymer (hereinafter sometimes referred to as “EAA”), an ethylene-methacrylic acid copolymer (hereinafter referred to as “EMAA”). Or the like).

  Examples of the ethylene-aliphatic unsaturated carboxylic acid ester copolymer include an ethylene-acrylic acid ester copolymer and an ethylene-methacrylic acid ester copolymer. As acrylic acid ester and methacrylic acid ester, ester with C1-C8 alcohol, such as methanol and ethanol, is used suitably.

  These copolymers may be multi-component copolymers obtained by copolymerizing three or more monomers. Examples of the multi-component copolymer include a copolymer obtained by copolymerizing at least three types of monomers selected from ethylene, aliphatic unsaturated carboxylic acid, and aliphatic unsaturated carboxylic acid ester.

  In the ethylene-aliphatic unsaturated carboxylic acid copolymer, the proportion of the aliphatic unsaturated carboxylic acid in all monomers constituting the copolymer is preferably 3 to 35% by mass. Moreover, it is preferable that MFR (190 degreeC, 2.16 kg) is 0.3g-30g, It is more preferable that it is 0.5g-30g, It is still more preferable that it is 0.8g-25g.

  In the ethylene-aliphatic unsaturated carboxylic acid ester copolymer, the proportion of the aliphatic unsaturated carboxylic acid ester in all monomers constituting the copolymer is preferably 3 to 35% by mass. Moreover, it is preferable that MFR (190 degreeC, 2.16 kg) is 0.3g-30g, It is more preferable that it is 0.5g-30g, It is still more preferable that it is 0.8g-25g.

  Examples of the polyolefin resin include a polyethylene resin, a polypropylene resin, and a polyolefin polymer alloy.

  As said polyethylene-type resin, polyethylene, an ethylene-alpha-olefin copolymer, etc. are mentioned, for example.

  Examples of the polyethylene include high density polyethylene, medium density polyethylene, low density polyethylene (LDPE), and ultra-low density polyethylene.

Here, polyethylene is classified by density based on JIS K 6922. Specifically, those having a density of 0.942 g / cm ³ or more are referred to as high-density polyethylene, and those having a density of 0.930 or more and less than 0.942 g / cm ³ are referred to as medium-density polyethylene, and the density is 0.910. Those having a density of less than 0.930 g / cm ³ are referred to as low density polyethylene, and those having a density of less than 0.910 g / cm ³ are referred to as ultra-low density polyethylene.

  The high-density polyethylene can be produced by a generally known method such as a Philips method, a standard method, or a Ziegler method.

  Examples of the medium density polyethylene include linear medium density polyethylene, and examples of the low density polyethylene include linear low density polyethylene (LLDPE) and high pressure method low density polyethylene. Here, the high pressure method low density polyethylene is a low density polyethylene produced by a so-called high pressure method (bulk polymerization method).

  Examples of the ultra-low density polyethylene include linear ultra-low density polyethylene (referred to as “VLDPE” and “ULDPE”).

  The ethylene-α-olefin copolymer refers to a copolymer composed of at least one selected from ethylene and α-olefin. The ethylene-α-olefin copolymer is preferably a copolymer composed of ethylene and at least one selected from α-olefins having 3 to 20 carbon atoms, and ethylene and α having 3 to 12 carbon atoms. -It is more preferable that it is a copolymer consisting of at least one selected from olefins. Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-decene, and 1-decene. Examples include dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosane and the like, and these can be used alone or in combination. The proportion of α-olefin in all monomers constituting the copolymer (based on charged monomers) is preferably 6 to 30% by mass. Further, the ethylene-α-olefin copolymer is preferably a soft copolymer, and preferably has a crystallinity of 30% or less by an X-ray method.

  In addition, as the ethylene-α-olefin copolymer, a copolymer of ethylene and at least one comonomer selected from propylene comonomer, butene comonomer, hexene comonomer, and octene comonomer is generally easily available. It can be used suitably.

The polyethylene resin can be polymerized using a known catalyst such as a single site catalyst or a multisite catalyst, and is preferably polymerized using a single site catalyst. The polyethylene resin preferably has a density of 0.860 to 0.920 g / cm ² , more preferably 0.870 to 0.915 g / cm ² from the viewpoint of cushioning properties, and 0.870 to 0.915 g / cm ^2. More preferably, it is 0.910 g / cm ² . As the density of the polyethylene resin is lower, the cushioning property tends to be improved. When the density is 0.920 g / cm ² or less, the transparency tends to be improved. When a high-density resin is used, transparency can be improved by adding low-density polyethylene, for example, at a ratio of about 30% by mass.

  From the viewpoint of sealing properties, the polyethylene resin preferably has an MFR (190 ° C., 2.16 kg) of 0.5 g to 30 g, more preferably 0.8 g to 30 g, and 1.0 g to 25 g. Is more preferable.

  As said polyethylene-type resin, the polyethylene-type copolymer which controlled crystal / amorphous structure (morphology) by nano order can also be used.

  As the polypropylene resin, polypropylene, propylene-α-olefin copolymer, terpolymer of propylene, ethylene, and α-olefin can be preferably used.

  The propylene-α-olefin copolymer refers to a copolymer composed of at least one selected from propylene and α-olefin. The propylene-α-olefin copolymer is preferably a copolymer composed of propylene and at least one selected from ethylene and an α-olefin having 4 to 20 carbon atoms. Propylene, ethylene and 4 to 8 carbon atoms are preferable. A copolymer composed of at least one selected from α-olefins is more preferable. Examples of the α-olefin having 4 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, and 3-methyl-1-pentene. , 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosane and the like, and these can be used alone or in combination. Moreover, it is preferable in the content rate (charge monomer reference | standard) of ethylene and / or alpha-olefin in all the monomers which comprise the said propylene-alpha-olefin copolymer being 6-30 mass%. Furthermore, the propylene-α-olefin copolymer is preferably a soft copolymer, and preferably has a crystallinity of 30% or less by an X-ray method.

  As the propylene-α-olefin copolymer, a copolymer of propylene and at least one comonomer selected from ethylene comonomer, butene comonomer, hexene comonomer, and octene comonomer is generally easily available, and preferably Can be used.

The polypropylene resin can be polymerized using a known catalyst such as a single-site catalyst or a multi-site catalyst, and is preferably polymerized using a single-site catalyst. The polypropylene resin preferably has a density of 0.860 to 0.920 g / cm ² , more preferably 0.870 to 0.915 g / cm ² from the viewpoint of cushioning properties, and 0.870 to 0.920 g / cm ^2. More preferably, it is 0.910 g / cm ² . Adhesiveness tends to improve as the density of the polypropylene resin decreases, and transparency tends to improve if the density is 0.920 g / cm ² or less.

  From the viewpoint of sealing properties, the polypropylene resin preferably has an MFR (230 ° C., 2.16 kgf) of 0.3 g to 25.0 g, more preferably 0.5 g to 20 g, and 0.8 g. More preferably, it is ˜15 g.

  As the polypropylene resin, a polypropylene copolymer in which the crystal / amorphous structure (morphology) is controlled in nano order can also be used.

  Examples of the polypropylene resin include copolymers of propylene and α-olefins such as ethylene, butene, hexene, and octene, or ternary compounds of propylene, ethylene and α-olefins such as butene, hexene, and octene. A copolymer etc. can be used conveniently. These copolymers may be in any form such as a block copolymer, a random copolymer, etc., preferably a random copolymer of propylene and ethylene, or a random copolymer of propylene, ethylene and butene. is there.

  The polypropylene resin may be not only a resin polymerized with a catalyst such as a Ziegler-Natta catalyst, but also a resin polymerized with a metallocene catalyst, for example, syndiotactic polypropylene, isotactic polypropylene, etc. it can. Further, the proportion of propylene in all monomers constituting the polypropylene resin (based on the charged monomers) is preferably 60 to 80% by mass. Further, from the viewpoint of excellent heat shrinkability, the propylene content ratio (based on the charged monomer) in all monomers constituting the polypropylene resin is 60 to 80% by mass, and the ethylene content ratio (based on the charged monomer) is 10 to 10%. A terpolymer having 30% by mass and a butene content ratio (based on charged monomers) of 5 to 20% by mass is preferred.

  When the base resin contains the polypropylene resin, it is preferable to use a resin obtained by uniformly finely dispersing a rubber component having a high concentration of 50% by mass or less with respect to the total amount of the polypropylene resin as the base resin. Here, as a rubber component, an ethylene propylene rubber component (EPR) is mentioned, for example.

  When the sealing layer 1 consists of only a tackifier and base resin, it is preferable that content of the tackifier in the sealing layer 1 is 5-40 mass% with respect to the sealing layer whole quantity, and 10-30 mass%. Is more preferable, and it is still more preferable that it is 15-30 mass%. When the content of the tackifier is within such a range, the transparency and adhesion performance of the seal layer tend to be improved.

  Moreover, when the sealing layer 1 consists only of a tackifier and base resin, it is preferable that content of the base resin in the sealing layer 1 is 60-95 mass% with respect to the sealing layer whole quantity, and 60-90 mass. % Is more preferable, and 55 to 85% by mass is even more preferable.

  The seal layer 1 may further contain an antistatic agent in addition to the tackifier and the base resin.

  Examples of the antistatic agent include polymeric antistatic agents, surfactants, conductive fine powders, etc. Among them, polymeric antistatic agents are preferable. Examples of the polymer antistatic agent include ionomer resins and polyether copolymers. According to such a polymer antistatic agent, antistatic properties can be imparted without impairing transparency and sealing properties.

  As ionomer resin, what substituted the carboxyl group with potassium or lithium ion is preferable.

  Examples of the polyether copolymer include a polyether / polyolefin block copolymer. The polyether copolymer preferably contains 2 to 30% of a lithium salt. When such a polyether copolymer is used, the conductive performance is further improved.

  The content of the antistatic agent in the seal layer 1 is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and 15 to 30% by mass with respect to the total amount of the seal layer. Is more preferable.

  The seal layer 1 is composed of a tackifier 10 to 30% by mass, an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene unsaturated carboxylic acid ester copolymer, and a polyolefin resin. It is particularly preferable to contain 40 to 80% by mass of at least one resin selected from the group and 10 to 30% by mass of at least one antistatic agent selected from an ionomer resin and a polyether copolymer. When the sealing layer contains such a material, the sealing performance is further improved.

  The sealing layer 1 is an optional additive such as various conductive materials, lubricants, plasticizers, antioxidants, ultraviolet absorbers, colorants, various surfactants, antiblocking agents, inorganic fillers, etc., as long as the properties are not impaired. May be included. Moreover, the coating process may be given.

  Here, examples of the anti-blocking agent include inorganic particles such as silica and alumina, and cyclic olefins. Cyclic olefins are particularly preferred because they do not drop off during taping and can be prevented from adhering to the contents (electronic parts). Examples of the cyclic olefin include Apel (trade name) manufactured by Mitsui Chemicals, Inc. and TOPAS (trade name) manufactured by Topas Advanced Polymers. An antiblock agent can be used 1 type or in combination of 2 or more types.

  The seal layer 1 may be a single layer or a plurality of layers. For example, it may be a plurality of layers obtained by laminating a layer containing a tackifier and a layer containing an antistatic agent. In this case, the order of laminating each layer is as seen from the outermost layer side of the film. The order may be the order of the layer containing the antistatic agent, the order of the layer containing the antistatic agent, or the order of the layer containing the antistatic agent and the seal layer containing the tackifier. Only the seal layer in which the tackifier and the antistatic agent are mixed may be disposed as the seal layer.

  The thickness of the sealing layer 1 is preferably 0.5 to 15% of the total thickness of the cover tape 10. When the thickness of the seal layer is 0.5% or more, the adhesive strength with the carrier tape is easily obtained stably, and when the thickness of the seal layer is 15% or less, the cover tape 10 has sufficient rigidity and shrinkage. It is preferable at the point obtained.

[Base material layer 2]
The base material layer 2 is a layer constituting the outermost surface on the side opposite to the seal layer 1. The base material layer 2 gives the cover tape 10 rigidity and heat resistance. That is, as the base material layer 2, a layer made of a resin composition having rigidity and heat resistance is preferable.

  The base material layer 2 includes, as a resin component, polyesters such as polymethylene terephthalate, polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and polylactic acid; aliphatic polyamides such as nylon 6, nylon 12, and nylon 66 Polymers; aliphatic polyamide copolymers such as nylon 6/66 and nylon 6/12; aromatic polyamide polymers such as MXD6 (polymetaxylene adipamide); high density polyethylene, medium density polyethylene, low density polyethylene ( LDPE), ultra-low-density polyethylene (especially high-pressure method high-density polyethylene, high-pressure method low-density polyethylene, linear low-density polyethylene, etc.), etc .; polypropylene; preferably containing polymethylpentene, etc. Kutomo 1 or more is selected.

  The base material layer 2 may further contain an antistatic agent. When the base material layer 2 further contains an antistatic agent, it is possible to prevent adhesion of dust or the like to the product when used as a cover tape.

  As an antistatic agent which the base material layer 2 contains, the said ionomer resin and the said polyether copolymer are mentioned, for example. The preferred forms of the ionomer resin and the polyether copolymer are the same as described above.

  Moreover, when the base material layer 2 contains an ionomer resin or a polyether copolymer, it is preferable that the content is 5-40 mass% with respect to the whole quantity of the base material layer 2, and 10-30 mass. %, More preferably 15 to 30% by mass.

  The base material layer 2 is an optional addition of various conductive materials, lubricants, plasticizers, antioxidants, ultraviolet absorbers, colorants, various surfactants, antiblocking agents, inorganic fillers, etc., as long as the properties are not impaired. An agent may be included. Moreover, the coating process may be given. In addition, the illustration and preferable form of an antiblocking agent are the same as the above.

  The thickness of the base material layer 2 is preferably 5 to 60% of the total thickness of the cover tape 10, and more preferably 10 to 50%. The rigidity of the cover tape can be adjusted by appropriately changing the thickness of the base material layer 2. When the thickness of the base material layer 2 is within the above range, rigidity suitable for a cover tape used in the taping reel system can be obtained.

[Intermediate layer 3]
The intermediate layer 3 is disposed between the base material layer 2 and the seal layer 1, and functions as a cushion layer that uniformly disperses the pressurization when, for example, heating and pressurization with a heat sealing iron. By uniformly dispersing the pressure, the heat-sealed cover tape adheres to the carrier tape with uniform adhesive strength. The intermediate layer 3 may have a single layer structure or a multilayer structure.

  The mid layer 3 preferably contains a resin composition containing a polyolefin resin. Examples of the polyolefin-based resin include the same ones as described above.

  The resin composition is composed of an ethylene-vinyl acetate copolymer, an ethylene-aliphatic unsaturated carboxylic acid copolymer, an ethylene-aliphatic unsaturated carboxylic acid ester copolymer, a polyolefin resin, a mixture thereof, and the like. It may further contain selected resin components. Examples of these are the same as above.

  The resin composition may further contain a polyolefin acid-modified product. The polyolefin acid-modified product means a product obtained by acid-modifying a polyolefin resin such as polyethylene or polypropylene with an unsaturated carboxylic acid such as maleic acid or fumaric acid or an acid anhydride thereof. By including such a polyolefin acid-modified product, the adhesiveness between the intermediate layer 3 and the base material layer 2 and the adhesiveness between the intermediate layer 3 and the seal layer 1 are further improved.

  The gel fraction of the resin composition is preferably 5 to 80% by mass, more preferably 7 to 68% by mass, and still more preferably 10 to 65% by mass. When the gel fraction of the resin composition is 80% by mass or less, the intermediate layer 3 can more uniformly disperse the pressure, and the peel strength between the cover tape and the carrier tape is further stabilized. . Further, if the gel fraction of the resin composition is 5% by mass or more, the flow of the intermediate layer due to pressurization at the time of heat sealing is sufficiently suppressed, so that lifting occurs at the end in the width direction of the cover tape. Can be further suppressed.

  The gel fraction of the resin composition can be appropriately adjusted by, for example, a method of performing crosslinking treatment by irradiating the resin composition with ionizing radiation such as ultraviolet rays, electron beams, X rays, and γ rays. Moreover, it can also adjust by adding the ultra high molecular weight polyethylene component in which molecular weight exceeds 1 million.

Here, the “gel fraction” indicates a value measured by the following method. That is, after measuring the initial mass of the sample to be measured, putting the sample in a 150 mesh stainless steel wire mesh, dipping in boiling paraxylene for 12 hours, extracting the insoluble matter, and mass of the insoluble matter after drying Measure. Then, the value calculated by the following formula is defined as “gel fraction”.
Gel fraction (mass%) = (mass of insoluble matter / initial mass of sample to be measured) × 100

  When the intermediate layer 3 has a multilayer structure, it is preferable that at least one of the layers constituting the intermediate layer is a layer made of a resin composition containing a polyolefin resin. As such an intermediate layer, for example, a middle layer of a two-layer structure comprising a first layer made of a resin composition containing a polyolefin resin and a second layer made of a resin composition not containing a polyolefin resin. Layer. The intermediate layer 3 includes a first layer made of a first resin composition containing a polyolefin resin and a second layer made of a second resin composition containing a polyolefin resin. It may be an intermediate layer.

  When the intermediate layer 3 has a multilayer structure, it is preferable that the gel fraction of the resin composition constituting each layer is within the above range. Moreover, it is more preferable that the gel fraction of the sample sample which mixed the resin composition which comprises each layer equally is in the said range.

  The intermediate layer 3 is an optional additive such as various conductive materials, lubricants, plasticizers, antioxidants, ultraviolet absorbers, colorants, various surfactants, antiblocking agents, and inorganic fillers, as long as the characteristics are not impaired. May be included. Moreover, the coating process may be given. In addition, the illustration and preferable form of an antiblocking agent are the same as the above.

  The thickness of the intermediate layer 3 is preferably 30 to 80%, more preferably 40 to 70% of the thickness of the entire cover tape 10. When the thickness of the intermediate layer 3 is in the above range, the pressure can be more uniformly dispersed during the heat and pressure at the time of heat sealing.

[Other layers]
Examples of layers other than the seal layer 1, the base material layer 2, and the intermediate layer 3 include a moisture-proof layer made of a barrier resin such as PVDC (polyvinylidene chloride). In addition, this layer has an optional addition of various conductive materials, lubricants, plasticizers, antioxidants, ultraviolet absorbers, colorants, various surfactants, antiblocking agents, inorganic fillers, etc., as long as the properties are not impaired. An agent may be included. Moreover, the coating process may be given. In addition, the illustration and preferable form of an antiblocking agent are the same as the above.

  Next, a preferred embodiment of the method for manufacturing the cover tape 10 will be described in detail.

[Manufacturing Method of Cover Tape 10]
The cover tape manufacturing method according to the present embodiment includes at least a first layer made of a resin composition constituting the base material layer 2 and a second layer made of a resin composition constituting the intermediate layer 3. A step of heating and stretching the laminate in at least one direction of MD and TD; Through this step, the first layer and the second layer become the base material layer 2 and the intermediate layer 3, respectively.

  The seal layer 1 can be produced by applying the resin composition constituting the seal layer 1 to the laminate that has been heat-stretched in the above step. It is preferable to further have a third layer made of the resin composition to be formed, and to heat and stretch together with the base material layer 2 and the intermediate layer 3.

  The laminate (hereinafter sometimes referred to as “unstretched original fabric”) can be produced, for example, by a method of forming a laminate by coating, extrusion lamination, or coextrusion. The multilayer coextrusion method will be described below.

  In the multilayer coextrusion method, for example, the resin composition constituting the first layer, the second layer, the third layer, and other layers as required is melt-extruded from a single extruder, and a multilayer die is obtained. It can be obtained by laminating in, melt coextrusion and quenching.

  Here, the method of melt coextrusion is not particularly limited, and examples thereof include a method using a multilayer T die or a multilayer circular die (annular die). Among these, a method using a multilayer circular die is preferable. The use of a multi-layer circular die is advantageous in terms of the required space for equipment and the amount of investment, and is suitable for high-mix low-volume production, making it easier to obtain heat shrinkability.

  Next, the melt coextruded resin is quenched. As the refrigerant used for the rapid cooling, water of 60 ° C. or less is usually suitably used. The refrigerant can be brought into direct contact with the molten resin or indirectly used as an internal refrigerant for the metal roll. When used as an internal refrigerant, oil or other known materials can be used in addition to water, and in some cases, it can be used in combination with blowing cold air.

  The laminated body thus obtained is heated, for example, to a temperature higher than the softening temperature of the resin constituting the laminated body and, for example, stretched 1.5 times or more in MD and 3 times or more in TD. The cover tape thus stretched has the predetermined heat shrinkage rate. The stretching ratio is appropriately selected according to the purpose, and if necessary, the heat shrinkage rate of the film may be adjusted by performing a heat treatment (thermal relaxation treatment) after stretching.

  Examples of the stretching method include a direct inflation method in which air or nitrogen is blown into a tube immediately after melt extrusion to perform stretching, and a film having a heat shrinkage rate may be obtained by this method. However, in order to develop a high heat shrinkage rate, a biaxial stretching method is preferable, and a tubular method (also referred to as a double bubble method) in which an unstretched raw material obtained by the above circular die is heated biaxially stretched. Is more preferable. That is, the cover tape of the present embodiment is preferably a biaxially stretched multilayer film produced by a tubular method that is biaxially stretched.

  The cover tape manufacturing method in the present embodiment may include a crosslinking step of crosslinking the resin before stretching or after stretching. When performing the crosslinking treatment, it is more preferable to carry out the crosslinking treatment by irradiation with energy rays before heating and stretching the resin. Thereby, the melt tension of the laminate in the heat stretching increases, and the stretching can be further stabilized. The stretched laminate may be irradiated with energy rays to crosslink the resin. Examples of energy rays to be used include ionizing radiation such as ultraviolet rays, electron beams, X-rays, and γ rays. Among these, an electron beam is preferable.

  Here, the electron beam is preferably used in a dose range of 10 to 300 KGy. From the viewpoint of imparting stretching stability to the laminate and imparting heat resistance to the cover tape, the irradiation amount is more preferably 50 kGy or more, and still more preferably 80 kGy or more. Further, from the viewpoint of imparting low temperature sealing properties, the irradiation amount is more preferably 280 kGy or less, and further preferably 250 kGy or less.

  The layer subjected to the crosslinking treatment can be arbitrarily selected according to the purpose. Further, for example, the vicinity of the surface of each layer may be mainly crosslinked. In this case, a method of adjusting and irradiating the dose distribution in the thickness direction by adjusting the acceleration voltage according to the thickness of the stretched fabric, and a mask irradiation method of adjusting the dose distribution in the same manner by using a shielding plate such as aluminum. For example, a method of irradiating an electron beam from an oblique direction with respect to the stretched original surface can be used.

  When the crosslinking treatment is performed, an arbitrary crosslinking inhibitor or crosslinking assistant (crosslinking accelerator) may be added to each layer including the resin to be crosslinked. Examples of the crosslinking aid include triallyl isocyanurate, trimethallyl isocyanurate, trimethylpropane triacrylate, triallyl cyanurate, and trimethallyl cyanurate.

  According to such a manufacturing method, the cover tape having the predetermined heat shrinkage rate can be easily manufactured.

  The cover tape according to the present embodiment is preferably a biaxially stretched film that is biaxially stretched at a temperature at which the stretching start point is equal to or higher than the melting peak temperature of the resin constituting the cover tape. In the case of a biaxially stretched film, the draw ratio is preferably 1.5 times or more for MD, 3 times or more for TD, and 1.8 times or more for MD, from the viewpoint of suppressing uneven thickness of the film. 4 times or more, more preferably 2 times or more in MD and 5 times or more in TD. The stretching start point refers to the position at which stretching starts at TD, and the temperature at the stretching start point refers to the surface temperature of the laminate at that position.

  Moreover, melting peak temperature is prescribed | regulated by measuring with the following method using a finger scanning calorimeter (DSC). The sample amount is 5 to 10 mg, the measurement atmosphere is a nitrogen atmosphere, and indium is used as the calorie standard. As the heating program, first, the sample was heated from 0 ° C. to 300 ° C. at a temperature increase rate of 10 ° C./min (1st. Melting behavior), left at 300 ° C. for 1 minute, and then the temperature decrease rate of 10 ° C./min. At 300 ° C. to 0 ° C. and left at 0 ° C. for 1 minute (1st. Crystallization behavior). Thereafter, the temperature is raised from 0 ° C. to 300 ° C. at a rate of temperature increase of 10 ° C./min (2nd. Melting behavior). The melting peak temperature is 2nd. In the specific heat curve obtained from the melting behavior, it is determined as the temperature showing the endothermic peak on the highest temperature side.

The cover tape according to the present embodiment is such that the temperature at the stretching start point is 5 ° C. or higher, preferably 7 ° C. or higher, more preferably 10 ° C. or higher, than the melting peak temperature of the resin constituting the cover tape. Biaxial stretching is preferred. By setting the temperature of the stretching start point as described above, a cover tape having a temperature T ₁ and a temperature T ₂ that satisfy the above formulas (i), (ii), and (iii) is obtained.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above embodiment, the cover tape includes the base material layer, the intermediate layer, and the seal layer. However, the cover tape according to the present invention is not necessarily limited to the one including all these three layers. It may have a layer structure or a two-layer structure. Such a cover tape can be manufactured, for example, by heating and stretching a resin film made of a resin composition constituting the cover tape in the same manner as described above.

  Hereinafter, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to only these examples. Note that the evaluation method and measurement method used in this embodiment are as follows.

(1) Gel fraction In 1000 ml of boiling paraxylene, 100 mg of a sample placed in a 150-mesh stainless steel wire mesh was extracted for 12 hours, and the ratio of insoluble matter expressed by the following formula was used as the gel fraction, and the film It was used as a measure of the degree of crosslinking of the resin. In addition, the gel fraction in the intermediate layer (B) was measured using the remainder obtained by removing the base material layer (A) and the seal layer (C) from the cover tape as a sample.
Gel fraction (mass%) = (mass of insoluble matter / sample weight before extraction) × 100

(2) Thermal shrinkage rate After putting a 100 mm square cover tape sample into an air oven type thermostat set at a predetermined temperature and subjecting it to heat treatment for 10 minutes in a freely shrinkable state, the distance between the center points of the sides facing each other is determined. Measure the shrinkage of the film and measure the shrinkage of each of MD and TD as a percentage of the percentage divided by the original dimension (distance between the center points of each facing side before heat treatment). It calculated | required as an arithmetic mean value. In addition, the measurement was performed at intervals of 20 ° C. in a temperature range of 80 to 200 ° C.

(3) Preparation of taping sample Using a semi-automatic taping machine PTS-180 manufactured by Palmec Co., Ltd., seal head width 0.5 mm × 2, seal head length 24 mm, seal head center distance 7.5 mm, seal pressure 0.4 MPa Cover tape slit to 9.5 mm width against PS embossed carrier tape (Sumitomo Bakelite Co., Ltd. Sumitomo Bakelite Co., Ltd.) of 12 mm width under conditions of feed length of 8 mm and sealing time of 0.3 seconds × 2 (double seal) Was used to heat seal at a temperature of 140 ° C. to prepare a taping sample.

(4) Cover tape twist evaluation About the taping sample created in (3), the displacement of the cover tape in the state heat-sealed to the PS embossed carrier tape was used using an Olympus Corporation laser microscope (LEXTOLS 4000). Measured.

  In addition, the displacement difference of the cover tape in MD and TD is 50 μm or less, and it is more preferable that the cover tape is not loose. The displacement difference of the cover tape in MD and TD is more than 50 μm and 100 μm or less. The case where there is a slack in the cover tape is next preferred, and when the displacement difference of the cover tape between MD and TD exceeds 100 μm and there is a significant slack in the cover tape, it is not suitable as a cover tape.

(5) Peeling strength About the taping sample prepared in (3), using a peeling strength tester PFT-50S manufactured by Palmec Co., Ltd. under the conditions of peeling speed = 300 mm / min, peeling angle = 170 °, 1 hour of taping After the lapse, the cover tape was peeled off and the peel strength was measured. The same measurement was performed three times in total, and the peel strength was determined from the arithmetic mean value.

(6) Surface specific resistance The surface specific resistance of the sealing layer of each cover tape was measured according to the resistivity measurement method described in JIS K6911 using a superinsulator SM-8220 (manufactured by Hioki Electric Co., Ltd.). The measurement temperature was 23 ° C. and the humidity was 50%.

  Resins used in Examples and Comparative Examples are as follows.

<Base material layer>
Ny1: Aliphatic polyamide (NOVAMID 2430A manufactured by Mitsubishi Chemical Corporation)
Ny2: Aromatic polyamide (Mitsubishi Chemical Corporation X21-F07)
HD: High-density polyethylene (manufactured by Asahi Kasei Chemicals Corporation Suntech HD J240, melt flow rate = 5.5 g / 10 min, density = 0.966 g / cm ³ )
Polymer-type conductive agent 1: polyether-polyolefin copolymer (Pelestat VH230, manufactured by Sanyo Chemical Co., Ltd.)
O-PET: Corona-treated biaxially stretched polyethylene terephthalate film (thickness 15 μm)

<Intermediate layer>
r-PP: Propylene-based copolymer (ADSYL 5C30F manufactured by Montel, melt flow rate = 5.5 g / 10 min, density = 0.922 g / cm ³ )
LDPE: High-pressure method low-density polyethylene (Suntech LDM2102, manufactured by Asahi Kasei Chemicals Corporation, melt flow rate = 0.2 g / 10 min, density = 0.922 g / cm ³ )
AD1: Maleic anhydride-modified polyethylene (manufactured by Mitsui Chemicals, Inc., Admer NF308, melt flow rate: 1.7 g / 10 min, density: 0.932 g / cm ³ )
LLDPE: ethylene-α-olefin random copolymer (Dow Chemical Japan Co., Ltd. dowlex 2032, polymerized with multi-site catalyst, α-olefin: 1-octene, melt flow rate: 2.0 g / 10 min, Density: 0.926 g / cm ³ )
<Sealing layer>
EVA: ethylene vinyl acetate copolymer (NUC3461, manufactured by Nippon Unicar Co., Ltd., vinyl acetate content = 20 mass%, melt flow rate = 14 g / 10 min, density = 0.940 g / cm ³ )
Tackifying resin: hydrogenated petroleum resin (Arukawa Chemical Co., Ltd. Alcon P125)
Polymer-type conductive agent 2: Polyether-polyolefin copolymer Lithium salt-containing compound (manufactured by Sanko Chemical Co., Ltd. TBX-25)
EVA emulsion: an emulsion containing a conductive agent composed mainly of EVA (manufactured by Chuo Rika Kogyo Co., Ltd.)
PE emulsion: An emulsion containing a conductive agent whose main component is PE (manufactured by Chuo Rika Kogyo Co., Ltd.)

[Example 1]
70% by mass of Ny1 as the base material layer (A), 20% by mass of Ny2 and 10% by mass of the polymer conductive agent 1, AD1 is used for the first intermediate layer (B1), and the second intermediate layer (B2) As the sealing layer (C), 70% by mass of r-PP and 30% by mass of LDPE, 60% by mass of EVA, 20% by mass of tackifying resin, and 20% by mass of polymer-type conductive agent 2 were used, respectively. A state in which the sealing layer (C) is arranged on the outside using an annular three-layer die so that the arrangement is A / B1 / B2 / C and the thickness ratio (%) of each layer is 30/5/55/10. After co-extrusion, the tube was rapidly cooled and solidified with cold water to obtain a tube-shaped unstretched original fabric having a uniform thickness accuracy for each layer having a folding width of 130 mm and a thickness of about 650 μm.

  While heating this unstretched raw fabric in a stretching machine, it passes between two pairs of differential nip rolls, and air is injected to stretch 3.0 times in MD and 4.3 times in TD (13 times in area stretch ratio). And a cover tape having a thickness of 50 μm was obtained. The evaluation results of the obtained cover tape are shown in Table 1. The heat shrinkage rate of the obtained cover tape at 60 ° C. was 3% / 3% for each of MD / TD.

[Example 2]
A cover tape having a thickness of 50 μm was obtained in the same manner as in Example 1 except that the tube-shaped unstretched raw material was irradiated with an electron beam (acceleration voltage = 1 MV, irradiation dose = 120 kGy). The evaluation results of the obtained cover tape are shown in Table 1. In addition, the thermal shrinkage rate at 60 ° C. of the obtained cover tape was 3% / 2% for MD / TD, respectively.

[Example 3]
As a base layer (A), 90% by mass of HDPE, 10% by mass of the polymer type conductive agent 1, 65% by mass of LLDPE as an intermediate layer (B), 35% by mass of LDPE, and as a sealing layer (C) EVA is 60% by mass, tackifying resin is 20% by mass, polymer conductive agent 2 is 20% by mass, the layer arrangement is A / B / C, and the thickness ratio (%) of each layer is 30/60/10. After the co-extrusion with the sealant layer (C) placed outside using a circular three-layer die so that it becomes, it is rapidly cooled and solidified with cold water, and each layer having a folding width of 130 mm and a thickness of about 650 μm is uniform. A tube-shaped unstretched raw fabric with thickness accuracy was obtained. A cover tape having a thickness of 50 μm was obtained in the same manner as in Example 1 except that this unstretched original fabric was irradiated with an electron beam (acceleration voltage = 1 MV, irradiation dose = 120 kGy). The evaluation results of the obtained cover tape are shown in Table 1.

[Example 4]
A cover tape having a thickness of 50 μm was obtained in the same manner as in Example 3 except that the irradiation dose in electron beam irradiation was 180 kGy. The evaluation results of the obtained tape are shown in Table 1.

[Example 5]
A cover tape having a thickness of 50 μm was obtained in the same manner as in Example 3 except that 60% by mass of LDPE and 40% by mass of PP were used as the intermediate layer (B). The evaluation results of the obtained tape are shown in Table 1.

[Example 6]
The substrate layer (A) is 90% by mass of HDPE and 10% by mass of the polymer type conductive agent, the intermediate layer (B) is 60% by mass of LDPE and 40% by mass of PP, and the layer arrangement is A / B. After co-extrusion using an annular two-layer die so that the intermediate layer (B) is arranged on the outside, it is rapidly cooled and solidified with cold water, and a uniform thickness is obtained for each layer having a folding width of 130 mm and a thickness of about 580 μm. A tube-shaped unstretched raw fabric with high accuracy was obtained. A tape having a thickness of 45 μm was obtained in the same manner as in Example 1 except that this unstretched original fabric was irradiated with an electron beam (acceleration voltage = 1 MV, irradiation dose = 120 kGy). After corona treatment of the surface of the obtained intermediate layer (B), an EVA emulsion is applied as a sealing layer (C) so that the thickness after drying is 5 μm, and the layer ratio (%) is 30/60/10. A cover tape having a thickness of 50 μm was obtained. The evaluation results of the obtained cover tape are shown in Table 1.

[Example 7]
A cover tape having a thickness of 50 μm was obtained in the same manner as in Example 6 except that PE emulsion was used as the sealing layer (C). The evaluation results of the obtained cover tape are shown in Table 1.

[Example 8]
The thickness is the same as in Example 6 except that the thickness ratio (%) of each layer of the base material layer (A) / intermediate layer (B) / sealing layer (C) is changed to 45/45/10. Obtained a cover tape of 50 μm. The evaluation results of the obtained cover tape are shown in Table 1.

[Comparative Example 1]
70% by mass of Ny1 as the base material layer (A), 20% by mass of Ny2 and 10% by mass of the polymer conductive agent 1, AD1 is used for the intermediate layer (B1), and r-PP is used as the intermediate layer (B2). 70% by mass, LDPE 30% by mass, EVA as a sealing layer (C) 60% by mass, tackifying resin 20% by mass, polymer conductive agent 2 20% by mass, and the layer arrangement is A / Using B1 / B2 / C, co-extruded with the sealing layer (C) placed outside using an annular three-layer die so that the thickness ratio (%) of each layer was 30/5/55/10 Thereafter, it was rapidly cooled and solidified with cold water to obtain a tube-shaped unstretched cover tape having a uniform thickness accuracy for each layer having a folding width of 130 mm and a thickness of about 50 μm. The evaluation results of the obtained cover tape are shown in Table 2.

[Comparative Example 2]
65% by mass of LLDPE and 35% by mass of LDPE were used as the intermediate layer (B2), 60% by mass of EVA, 20% by mass of tackifying resin, and 20% by mass of polymer conductive agent 2 as the sealing layer (C). Using an annular die, co-extruded with the seal layer (C) arranged on the outside, and then rapidly cooled and solidified with cold water to obtain a tube-shaped unstretched original fabric having a folding width of 130 mm and a thickness of about 410 μm It was. After this unstretched raw material was irradiated with an electron beam (acceleration voltage = 1 MV, irradiation dose = 120 kGy), it was passed through two pairs of differential nip rolls while being heated in a stretching machine, and air was injected into the MD. The film was stretched 0 times and 4.2 times to TD (13 times in area stretch ratio) to obtain an intermediate layer (B2) / seal layer (C) laminated film having a thickness of 33 μm.

  A biaxially stretched polyethylene terephthalate film having a thickness of 15 μm is used as the base material layer (A), and the thickness after drying the urethane anchor coat agent as the intermediate layer (B1) on one side surface of O-PET is 2 μm. The intermediate layer (B2) / sealing layer (C) laminated film is laminated by dry lamination, and the base layer (A) / intermediate layer (B1) / intermediate layer (B2) / sealing layer ( A cover tape having a C) layer ratio (%) of 30/5/55/10 and a thickness of 50 μm was obtained. The evaluation results of the obtained cover tape are shown in Table 2.

[Comparative Example 3]
A composition comprising 65% by mass of LLDPE and 35% by mass of LDPE was extruded using an annular die, and then rapidly cooled and solidified with cold water to obtain a tubular unstretched original fabric having a folding width of 130 mm and a thickness of about 350 μm. . After this unstretched raw material was irradiated with an electron beam (acceleration voltage = 1 MV, irradiation dose = 120 kGy), it was passed through two pairs of differential nip rolls while being heated in a stretching machine, and air was injected into the MD. The film was stretched by 0 times and TD by 4.2 times (13 times by area stretch ratio) to obtain a film having a thickness of 28 μm. What obtained by corona-treating both surfaces of the obtained film was used as an intermediate | middle layer (B2).

  A biaxially stretched polyethylene terephthalate film having a thickness of 15 μm is used as the base material layer (A), and the thickness after drying the urethane anchor coat agent as the intermediate layer (B1) on one side surface of O-PET is 2 μm. The intermediate layer (B2) film was laminated by dry lamination.

  As the sealing layer (C), the EVA emulsion was applied to the surface of the intermediate layer (B) so that the thickness after drying was 5 μm, the layer ratio (%) was 30/5/55/10, and the thickness was A cover tape of 50 μm was obtained. The evaluation results of the obtained cover tape are shown in Table 2.

  From the results in Table 1, the cover tapes obtained in Examples 1 to 8 had an appropriate heat shrinkage rate, and tight packaging was obtained immediately after heat sealing without any looseness of the cover tape. On the other hand, from the results of Table 2, the cover tapes obtained in Comparative Examples 1 to 3 were rough packaging in which the looseness of the cover tape was not eliminated immediately after heat sealing.

  By using the cover tape of the present invention, immediately after heat sealing, the cover tape does not sag and tight packaging is possible, and electronic components can be prevented from being damaged due to vibration during transportation. Can be prevented from transferring from.

  DESCRIPTION OF SYMBOLS 1 ... Seal layer, 2 ... Base material layer, 3 ... Intermediate layer, 10 ... Cover seal, 11 ... Electronic component package, 20 ... Carrier tape, 21 ... Pocket for electronic component storage, 30 ... Electronic component, 50 ... Heat seal Iron for iron.

Claims (6)

A base layer, a seal layer, and an intermediate layer disposed between the base layer and the seal layer,
Have a temperature of flow direction and flow Re definitive perpendicular width direction toward the direction thermal shrinkage becomes both more than 5% between 80 to 200 ° C., and,
Formula (i), (ii), (iii) and (iv), having a temperature _{T 1} and _{T 2} satisfying in both the flow direction and the width direction, the cover tape.
0 ° C. <T ₁ −T ₂ ≦ 60 ° C. (i)
S ₁ -S ₂ ≧ 20% (ii)
80 ° C. ≦ T ₁ ≦ 200 ° C. (iii)
60 ° C. ≦ T ₂ (iv)
[Wherein, S ₁ represents the heat shrinkage rate (%) at the temperature T ₁ , and S ₂ represents the heat shrinkage rate S ₂ (%) at the temperature T ₂ . ] The cover tape according to claim 1 , wherein the intermediate layer contains a resin composition containing a polyolefin-based resin, and the gel fraction of the resin composition is 5 to 80% by mass. The cover tape according to claim 1 or 2 whose thickness of said seal layer is 0.5 to 15% of the thickness of said whole cover tape. The cover tape according to any one of claims 1 to 3 , wherein a surface specific resistance value of the seal layer is 1 x 10 ⁴ to 1 x 10 ¹³ Ω. It is a manufacturing method of the cover tape for manufacturing the cover tape as described in any one of Claims 1-4 ,
A cover comprising a step of heating and stretching a laminate having at least a first layer comprising a resin composition constituting the base material layer and a second layer comprising a resin composition constituting the intermediate layer. Tape manufacturing method. The electronic component package using the cover tape as described in any one of Claims 1-4 .

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