Cover tape and electronic component package comprising same

Abstract

The present invention addresses a first problem of providing: a cover tape that is less likely to absorb moisture even under high temperature and high humidity conditions and that has good visibility; and an electronic component package including the same.　The first problem is solved by a cover tape (I) in which the transmittance is at least 75% for wavelengths of 1300-1500 nm and the haze value is less than 30%.

Description

Cover tape and electronic component packaging including same

[0001] The present invention relates to a cover tape and an electronic component package including the same.

[0002] As electronic devices become smaller, the electronic components used are also becoming smaller and more powerful. At the same time, electronic components are being automatically mounted on printed circuit boards during the assembly process of electronic devices. These chip-type surface-mount electronic components are housed in a carrier tape with a series of thermoformed storage pockets formed to fit the shape of the electronic components. After the electronic components are housed in each storage pocket, a cover tape is placed on top of the carrier tape as a lid, and both ends of the cover tape are heat-sealed continuously in the longitudinal direction with a heated sealing iron to form a package for the electronic components.

[0003] However, cover tapes may be exposed to high-temperature and high-humidity environments during transportation and storage, which can cause the cover tape to absorb moisture. If the moisture absorption rate of the cover tape becomes too high, problems such as blocking may occur in the rolled cover tape and reduced heat-sealing properties may occur. Furthermore, if the cover tape absorbs moisture after being used as an electronic component package, there is a concern that this may affect the electronic components contained therein.

[0004] To address this issue, for example, Patent Document 1 proposes a cover tape that is less likely to cause blocking even when exposed to high temperature or high temperature and humidity environments. On the other hand, no study has been conducted on a cover tape that is less likely to absorb moisture even under high temperature and high humidity conditions.

[0005] Furthermore, the cover tape used in the electronic component package is required to have sufficient visibility to allow the enclosed electronic components to be visually observed from the cover tape side. However, no cover tape that is resistant to moisture absorption even under high temperature and high humidity conditions and also has good visibility is known.

[0006] Furthermore, as a result of investigations by the present inventors, it was found that the cover tape absorbs moisture even under high temperature and low humidity conditions, which makes it prone to the above-mentioned problems.

[0007] As described above, the cover tape is required to have a transparency sufficient to allow the contents inside to be visually recognized. For example, Patent Document 2 proposes a highly transparent cover tape.

[0008] In recent years, with the further miniaturization of electronic components, camera inspection using near-infrared cameras and the like has become mainstream instead of visual inspection. Near-infrared cameras can capture near-infrared light that is invisible to the human eye, so they can be used to detect defects in electronic components contained in electronic component packaging through cover tape and to recognize circuits printed on electronic components. However, conventional cover tapes have low transmittance in the near-infrared wavelength range, resulting in insufficient visibility in near-infrared camera inspections.

[0009] International Publication No. WO 2013 / 054867 International Publication No. WO 2019 / 087999

[0010] A first object of the present disclosure is to provide a cover tape that is resistant to moisture absorption even under high temperature and high humidity conditions and has good visibility, and an electronic component package including the same.

[0011] A second object of the present disclosure is to provide a cover tape that absorbs little moisture even under high temperature and low humidity conditions, and an electronic component package including the same.

[0012] A third object of the present disclosure is to provide a cover tape having high transmittance in the near-infrared wavelength range and an electronic component package including the same.

[0013] As a result of intensive research into the above-mentioned problems, the inventors of the present application have found that the first problem can be solved by a cover tape (1) according to the following first embodiment: [1] A cover tape (I) having a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%.

[0014] Furthermore, it has been found that the second problem can be solved by a cover tape (II) according to the following second embodiment: <1> A cover tape (II) having a transmittance of more than 80% at wavelengths of 1300 to 1500 nm.

[0015] Furthermore, the third problem can be solved with the cover tape (III) according to the third embodiment described below. "1" A cover tape (III) having a moisture absorption rate (a) of 1500 mass ppm or less, measured under the following conditions: <Conditions> After storing the cover tape (III) under dry conditions of 60°C / 20% RH for 12 hours, the moisture absorption rate (a) of the cover tape (III) is measured at a holding temperature of 280°C according to JIS K0068:2001 "Karl Fischer titration method, moisture evaporation-coulometric titration method."

[0016] The cover tape (I) according to the first embodiment of the present disclosure can solve the first problem described above, that is, it is possible to provide a cover tape (I) that is resistant to moisture absorption even under high temperature and high humidity conditions and has good visibility, and an electronic component package (I) including the cover tape (I).

[0017] The cover tape (II) according to the second embodiment of the present disclosure can solve the second problem, i.e., it is possible to provide a cover tape (II) that exhibits low moisture absorption even under high temperature and low humidity conditions, and an electronic component package (II) including the cover tape (II).

[0018] The cover tape (III) according to the third embodiment of the present disclosure can solve the third problem, i.e., it is possible to provide a cover tape (III) having high transmittance in the near-infrared wavelength range and an electronic component package (III) including the cover tape (III).

[0019] Graph showing the transmittance measurement results of the cover tapes (I) of Examples I-1 to I-6 and Comparative Examples I-1 to I-3. Graph showing the transmittance measurement results of the cover tapes (II) of Examples II-1 to II-5 and Comparative Examples II-1 to II-3. Graph showing the transmittance measurement results of the cover tapes (III) of Examples III-1 to III-4 and Comparative Examples III-1 to III-3.

[0020] An embodiment of the present disclosure will be described in detail below. However, the scope of the present disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of the present disclosure. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Furthermore, when multiple upper and lower limits are described for a particular parameter, any of these upper and lower limits can be combined to form a suitable numerical range. Furthermore, the lower and / or upper limits of a numerical range described in this disclosure are numerical values ​​within that range and may be replaced with numerical values ​​shown in the examples. The expression "X to Y" indicating a numerical range means "X or more and Y or less." If a specific description described for one embodiment also applies to other embodiments, that description may be omitted in other embodiments.

[0021] The configurations and combinations thereof in each embodiment are merely examples, and additions, omissions, substitutions, and other modifications of the configurations are possible as appropriate without departing from the spirit of the present disclosure. The present disclosure is not limited to the embodiments. Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification.

[0022] [First Embodiment: Cover Tape (I)] The first embodiment of the present disclosure relates to a cover tape (I). The cover tape (I) according to the first embodiment has a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%. Light with a wavelength of 1300 to 1500 nm is light in the near-infrared wavelength range. Thus, the cover tape (I) with a transmittance of 75% or more in the near-infrared wavelength range and a haze value of less than 30% is less likely to absorb moisture even under high temperature and high humidity conditions. It also has good visibility. In other words, the cover tape (I) can solve the first problem.

[0023] In the first embodiment of the present disclosure, "transmittance of 75% or more at wavelengths of 1300 to 1500 nm" means that the transmittance of the cover tape (I) is 75% or more at any wavelength within that wavelength range, which is different from an average transmittance of 75% or more in that wavelength range. Furthermore, in the first embodiment of the present disclosure, "good visibility" includes the ability to confirm the orientation of the enclosed electronic components and the letters and serial numbers printed on the surfaces of the electronic components from the cover tape (I) side using a digital microscope or the like when the cover tape (I) is used as an electronic component package (I).

[0024] <Transmittance> The transmittance of the cover tape (I) according to the first embodiment can be measured by the following method. (Method for Measuring Transmittance) As a measurement and analysis device, an ultraviolet-visible-near-infrared spectrophotometer (for example, manufactured by Shimadzu Corporation, product name "UV-3600") and a multipurpose large sample chamber (φ60 mm, with built-in integrating sphere; for example, manufactured by Shimadzu Corporation, product name "MPC-3100") are used. First, baseline correction is performed without the cover tape (I), and then the cover tape (I) is attached and the spectral transmittance at wavelengths of 1200 to 1600 nm is measured using an integrating sphere.

[0025] In one embodiment, from the viewpoint of easily obtaining a cover tape (I) that is less likely to absorb moisture under high temperature and high humidity, the transmittance at a wavelength of 1300 to 1500 nm may be 77% or more, 78% or more, 79% or more, or even 80% or more. In one embodiment, the transmittance in this wavelength range may be 90% or more. Note that, from the viewpoint of obtaining a cover tape (I) that is less likely to absorb moisture under high temperature and high humidity, the upper limit of the transmittance in this wavelength range is not particularly limited.

[0026] The cover tape (I) according to the first embodiment preferably has a transmittance of 75% or more at wavelengths of 1200 to 1600 nm. According to the studies of the present inventors, it has been found that a cover tape (I) having a transmittance of 75% or more at a wavelength range even wider than the wavelength range of 1300 to 1500 nm is less likely to absorb moisture under high temperature and high humidity conditions. In this disclosure, "a transmittance of 75% or more at wavelengths of 1200 to 1600 nm" means that the cover tape (I) has a transmittance of 75% or more at any wavelength within that wavelength range, which is different from an average transmittance of 75% or more within that wavelength range.

[0027] In one embodiment, the transmittance at wavelengths of 1200 to 1600 nm may be greater than 75%, or may be 76% or greater. In one embodiment, the transmittance at wavelengths of 1200 to 1600 nm may be 80% or greater, 85% or greater, or 87% or greater. From the viewpoint of obtaining a cover tape (I) that is less likely to absorb moisture under high temperature and high humidity conditions, the upper limit is not particularly limited.

[0028] In one embodiment, the cover tape (I) may have a change rate of 90% or more of the transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, as expressed by the following formula (1): (T2 / T1) × 100(%) (1)

[0029] If the rate of change represented by the formula (1) is 90% or more, the cover tape (I) is likely to be less hygroscopic under high temperature and high humidity conditions. For example, when the transmittance (T2) at a wavelength of 1600 nm is 75%, a cover tape (I) having a transmittance (T1) at a wavelength of 1200 nm of 83.3% or more is preferred as a cover tape (I) that satisfies the formula (1). Furthermore, the cover tape (I) having a transmittance of 75% or more at wavelengths of 1200 to 1600 nm is preferred because it is likely to have a rate of change represented by the formula (1) of 90% or more.

[0030] The upper limit of the rate of change expressed by the formula (1) is not particularly limited as long as the effects of the present invention are maintained. The cover tape (I) according to the first embodiment may also include a case where T1<T2, and therefore the rate of change may be 100% or more. In one embodiment, the rate of change may be 90 to 105%, 90 to 102%, or 95 to 102%.

[0031] <Haze Value> The haze value of the cover tape (I) according to the first embodiment is less than 30%. By having the transmittance described above and a haze value of less than 30%, the cover tape (I) has good visibility and is less likely to absorb moisture even under high temperature and high humidity conditions. The haze value of the cover tape (I) can be measured by the following method. (Method for Measuring Haze Value) The haze value of the cover tape (I) is measured using a haze meter (for example, a product named "Haze Meter NDH 7000" manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1:1997.

[0032] From the viewpoint of improving visibility, the haze value of the cover tape (I) is preferably 28% or less, more preferably 26% or less, and even more preferably 25% or less.

[0033] For example, as in the case of cover tape I-7 shown in Comparative Example I-1 below, the transmittance of a typical cover tape tends to gradually decrease as the wavelength shifts toward higher near-infrared wavelengths. In the case of cover tape I-7 shown in Comparative Example I-1, the transmittance at 1300 nm and 1400 nm is 75% or higher, but the transmittance at 1500 nm is less than 75%. Furthermore, the aforementioned increase / decrease rate for such a cover tape is less than 90%. The present inventors conducted research into cover tapes that are less likely to absorb moisture under high temperatures and high humidity, and found that there is a correlation between the transmittance of the cover tape in the near-infrared wavelength range and its moisture absorption rate under high temperatures and high humidity. In other words, the present inventors' research revealed that cover tapes such as those in Comparative Example I-1 are prone to moisture absorption under high temperatures and high humidity. Therefore, research was conducted into cover tapes that are less likely to absorb moisture under high temperatures and high humidity by increasing the transmittance in the near-infrared wavelength range. It was also found that designing a cover tape with a high transmittance increases the haze value, which in turn reduces visibility. That is, in order to create a cover tape (I) that is resistant to moisture absorption even under high temperature and high humidity conditions and has good visibility, it is necessary to increase the transmittance in the near-infrared wavelength range and reduce the haze value. However, as shown in Comparative Example I-3, the transmittance and haze value are in a trade-off relationship, making it very difficult to achieve both. As a result of extensive research, the inventors of the present application have succeeded in developing a cover tape (I) that has a transmittance of 75% or more in the near-infrared wavelength range and a haze value of less than 30% by selecting the resin components that make up the cover tape (preferably, designing the resin components of the cover tape so that they do not contain polyamide-based resins), and further by laminating each layer so that the layer surface is smooth when laminating the cover tape (preferably, laminating so that the surface of the intermediate layer that contacts the heat seal layer is smooth). Such a cover tape (I) is resistant to moisture absorption even under high temperature and high humidity conditions, and is less likely to cause problems caused by moisture absorption by the cover tape. Furthermore, visibility is also good when used as an electronic component package. In the present disclosure, the term "polyamide resin" refers to a polyamide resin containing an aliphatic skeleton, which is generally called nylon (registered trademark).

[0034] <Layer Structure> The cover tape (I) according to the first embodiment can have a multilayer structure in which a base layer, an intermediate layer, and a heat seal layer are laminated in this order. It is preferable to select thermoplastic resins and additives for each layer constituting the cover tape (I) according to the first embodiment so that the transmittance of the cover tape (I) at wavelengths of 1300 to 1500 nm is 75% or more. Furthermore, it is preferable to laminate each layer so that the layer surface is smooth. In a preferred embodiment, from the viewpoint of easily achieving the above transmittance, each layer constituting the cover tape (I) does not contain a polyamide resin.

[0035] Below, we will describe an example of a cover tape (I) that has at least a base layer, an intermediate layer, and a heat seal layer and that is likely to achieve the transmittance requirements of the cover tape (I) according to the first embodiment, but the configuration of the cover tape (I) according to the first embodiment is not limited to the following.

[0036] <Base layer> The base layer is a layer containing a thermoplastic resin, and is preferably made of a film formed from the thermoplastic resin. The thermoplastic resin constituting the base layer is preferably selected from the viewpoint of easily achieving a transmittance of 75% or more at a wavelength of 1300 to 1500 nm and satisfying the mechanical properties required for the cover tape (I). In one embodiment, polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate, polyolefin-based resins such as polypropylene, polycarbonate-based resins, etc. are preferred. Furthermore, it is more preferable that the base layer is made of a biaxially stretched film.

[0037] The substrate layer preferably does not contain a polyamide resin, and is more preferably made of a polyester resin film such as a biaxially oriented polyethylene terephthalate film or a biaxially oriented polyethylene naphthalate film.

[0038] The thickness of the substrate layer is generally set arbitrarily within the range of 5 to 50 μm, taking into consideration the mechanical properties of the cover tape (I). In the cover tape (I) according to the first embodiment, it is preferable to set the thickness of the substrate layer so that the transmittance in the near-infrared wavelength range is 75% or more. From these viewpoints, the thickness of the substrate layer is preferably 10 to 30 μm, more preferably more than 10 μm and 30 μm or less, and even more preferably 12 to 20 μm. In one embodiment, the thickness of the substrate layer may be more than 10 μm and 20 μm or less, or may be 13 to 16 μm.

[0039] In one embodiment, at least one surface of the substrate layer may be surface-treated. Examples of the surface treatment include sandblasting, corona discharge treatment, and plasma treatment. In one embodiment, the surface of the substrate layer on which the intermediate layer is laminated is preferably surface-treated. By surface-treating the substrate layer, the adhesive strength between the substrate layer and the intermediate layer is likely to be improved.

[0040] <Intermediate Layer> The intermediate layer is a thermoplastic resin layer laminated on one side of the substrate layer, optionally via an adhesive layer or anchor coat layer. The present inventors have found that the transmittance of the cover tape in the near-infrared wavelength range is easily affected by the thermoplastic resin constituting the intermediate layer. After further investigation, the present inventors have found that when the intermediate layer does not contain a polyamide-based resin, the transmittance at wavelengths of 1300 to 1500 nm is likely to be 75% or higher. Furthermore, from the viewpoint of also easily achieving a transmittance at wavelengths of 1200 to 1600 nm of 75% or higher, it has also been found that it is preferable for the intermediate layer to contain a polyolefin-based resin and not a polyamide-based resin.

[0041] Examples of polyolefin resins that can be used include polyethylene (e.g., low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE)), ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-maleic acid copolymer, styrene-ethylene graft copolymer, styrene-propylene graft copolymer, styrene-ethylene-butadiene block copolymer, and polypropylene. These polyolefin resins may be used alone or as a mixture of two or more. The intermediate layer may also be two or more layers made of different polyolefin resins, such as a layer made of polyethylene and a layer made of ethylene-1-butene copolymer.

[0042] From the viewpoint of easily obtaining a cover tape (I) that has a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and is less likely to absorb moisture under high temperature and high humidity conditions, the intermediate layer preferably contains only a polyolefin resin as a resin component, and more preferably contains only LLDPE.

[0043] The intermediate layer may be composed of one layer (single layer structure), or may have a multilayer structure in which two or more layers are laminated. In the case of a multilayer structure, from the viewpoint of transmittance and the tendency for the haze value to be low, it is preferable to have a structure in which two or more layers of the same type of polyolefin resin are laminated. Here, "the same type of polyolefin resin" means that the olefin units contained in the polyolefin resin are the same, but the molecular weights, etc., may be different. In the case of a multilayer structure, the intermediate layer may be laminated directly on the substrate layer without an anchor coat layer interposed therebetween.

[0044] When the intermediate layer contains LLDPE, it is preferably linear low-density polyethylene (m-LLDPE) polymerized with a metallocene catalyst.

[0045] The m-LLDPE is a copolymer of ethylene and an olefin having 3 or more carbon atoms, preferably a linear, branched, or aromatic nucleus-substituted α-olefin having 3 to 18 carbon atoms, as a comonomer. Examples of linear monoolefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. Examples of branched monoolefins include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, and 2-ethyl-1-hexene. Examples of aromatic nucleus-substituted monoolefins include styrene. These comonomers can be copolymerized with ethylene either alone or in combination. In this copolymerization, polyenes such as butadiene, isoprene, 1,3-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene may be copolymerized.

[0046] In the cover tape, the thickness of the intermediate layer is generally 5 to 50 μm, preferably 10 to 40 μm. The thickness of the intermediate layer is generally set from the viewpoint of various physical properties such as the adhesive strength between the intermediate layer and the base layer and the peel strength during heat sealing. In the cover tape (I) according to the first embodiment, it is preferable to control the thickness of the intermediate layer from the viewpoint of obtaining a cover tape (I) that has low moisture absorption under high temperature and high humidity conditions and good visibility. In one embodiment, the thickness of the intermediate layer is preferably 10 to 40 μm, more preferably 13 to 38 μm. The thickness of the intermediate layer may also be 20 to 38 μm.

[0047] In a preferred embodiment, the intermediate layer and the heat seal layer are laminated so that the surface of the intermediate layer that comes into contact with the heat seal layer is smooth.

[0048] <Heat Seal Layer> The heat seal layer is selected from the viewpoint of containing a thermoplastic resin that has heat sealability to the carrier tape and exhibits easy peelability, allowing for easy peeling during use. In the first embodiment, it is also preferable to select a material that is likely to have a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a low haze value. From these viewpoints, preferred thermoplastic resins contained in the heat seal layer include ethylene-based resins such as polyethylene (e.g., LDPE, LLDPE, VLDPE, etc., as exemplified for the intermediate layer above), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butene-1 random copolymer; and styrene-based resins such as styrene-butadiene copolymer (SB), styrene-butadiene-styrene block copolymer (SBS) or its hydrogenated product (SEBS), polystyrene (PS), styrene-butadiene copolymer (SBC), and high-impact polystyrene (HIPS). These thermoplastic resins may be used alone or in combination of two or more.

[0049] In a preferred embodiment, from the viewpoint of making it easier to obtain a cover tape (I) having a transmittance of 75% or more at a wavelength of 1200 to 1600 nm, the heat seal layer preferably contains at least one styrene-based resin selected from SB, SEBS, and SBC as a main component, or more preferably contains only an olefin-based resin.

[0050] The thickness of the heat seal layer is generally set from the viewpoint of heat sealing properties with the carrier tape. In the cover tape (I) according to the first embodiment, it is preferable to control the thickness of the heat seal layer from the viewpoint of easily controlling the transmittance at wavelengths of 1300 to 1500 nm to 75% or more and easily obtaining a cover tape (I) with a haze value of less than 30%. In one embodiment, the thickness of the heat seal layer is preferably less than 20 μm, preferably 3 μm or more but less than 20 μm, and more preferably 5 to 15 μm. In one embodiment, the thickness of the heat seal layer may be 3 to 25 μm.

[0051] In one embodiment, the heat seal layer may contain one or more antistatic agents, which will be described later. When the heat seal layer contains an antistatic agent, the heat seal layer has heat sealability and antistatic properties.

[0052] (Adhesive Layer or Anchor Coat Layer) In one embodiment, an adhesive layer or anchor coat layer can be provided between the intermediate layer and the base layer, or between the intermediate layer and the heat seal layer. When an adhesive layer or anchor coat layer is provided, anchor coating agents such as polyurethane adhesives, polyethyleneimine, modified polybutadiene, and organic titanate compounds, and hot melt adhesives such as polyolefin resins, ethylene-vinyl acetate resins, ethylene-acrylic acid ester resins, and vinyl chloride-vinyl acetate resins can be used. Among these, from the viewpoint of providing a cover tape that is less prone to moisture absorption under high temperature and high humidity conditions and that also has good visibility, it is preferable that the anchor coat layer contain a polyurethane adhesive.

[0053] In one embodiment, it is preferable to provide an anchor coat layer between the intermediate layer and the base layer. When the intermediate layer is laminated via the anchor coat layer, the polyolefin resin constituting the intermediate layer is preferably a single layer, and it is more preferable to have an intermediate layer structure consisting of base layer / anchor coat layer / polyolefin resin such as LLDPE. With such a structure, the transmittance is likely to be 75% or more, and the cover tape (I) is likely to have low moisture absorption under high temperature and high humidity conditions. In addition, the haze value is likely to be less than 30%.

[0054] (Antistatic Layer) The cover tape according to the first embodiment may further comprise an antistatic layer. The antistatic layer may be provided on the heat seal layer and / or on the surface of the substrate layer that is not in contact with the intermediate layer. By providing an antistatic layer, the cover tape (I) can be provided with an antistatic effect, making it easier to prevent static breakdown of electronic components. As mentioned above, when the heat seal layer contains an antistatic agent, an antistatic layer need not be provided on the heat seal layer.

[0055] The antistatic layer is a layer containing an antistatic agent. The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape (I) and easily achieving the aforementioned transmittance. In one embodiment, the antistatic agent may be selected from conductive fine particles such as barium sulfate, tin oxide, zinc oxide, indium oxide, titanium oxide, aluminum oxide, and antimony-doped tin oxide (ATO); ionic liquids containing cyclic quaternary nitrogen-containing cations; cationic surfactants such as quaternary ammonium salts; polyalkylene oxides (e.g., polyethylene glycol, polypropylene glycol, polybutylene glycol, ethylene oxide-propylene oxide copolymer, etc.), polyalkylene glycols such as polyether esters having a polyoxyalkylene structure and an ester bond, and the like.

[0056] As the ionic liquid containing a cyclic quaternary nitrogen-containing cation (hereinafter simply referred to as "ionic liquid"), from the viewpoint of easily achieving the above-mentioned transmittance and easily imparting the desired antistatic properties, for example, 1,3-dimethylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-dimethylimidazolium phosphate, 1,3-dimethylimidazolium hydrozine sulfate, etc. can be used.

[0057] As the quaternary ammonium salt, from the viewpoint of easily achieving the above-mentioned transmittance and easily imparting the desired antistatic properties, for example, trimethyl lauryl ammonium methyl sulfate, ethyl dimethyl stearyl ammonium ethyl sulfate, ethyl dimethyl oleyl ammonium ethyl sulfate, ethyl dimethyl lauryl ammonium ethyl sulfate, ethyl dimethyl stearyl ammonium metasulfonium, ethyl dimethyl lauryl ammonium metasulfonium, etc. can be used.

[0058] The antistatic layer may further contain the antistatic agent and a binder resin. Examples of binder resins include polyurethane resins, acrylic resins, polyvinyl chloride resins, ethylene-vinyl acetate resins, polyester resins, butadiene resins, styrene resins including hydrogenated resins, and acrylic-modified polyester resins, and these may be used alone or in combination. From the viewpoint of easily controlling the transmittance at wavelengths of 1300 to 1500 nm to 75% or more, it is preferable that the binder resin does not contain a polyamide resin.

[0059] When the cover tape (I) according to the first embodiment has an antistatic layer, it preferably contains at least one selected from the group consisting of an ionic liquid, ATO, and alumina oxide, from the viewpoint of easily achieving a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a transmittance of 75% or more at wavelengths of 1200 to 1600 nm. Furthermore, when the aforementioned preferred antistatic agent is blended, the proportion of the antistatic agent is preferably 90% by mass or less relative to the total mass of the resin composition constituting the antistatic layer.

[0060] The thickness of the antistatic layer is preferably 0.01 to 2.0 μm from the viewpoint of easily achieving both antistatic properties and the above-mentioned transmittance.

[0061] (Total Thickness of Cover Tape (I)) The total thickness of the cover tape (I) according to the first embodiment is preferably 40 to 65 μm from the viewpoint of easily achieving the various physical properties required for the cover tape (I) and the transmittance and haze value described above. Furthermore, from the viewpoint of easily obtaining a cover tape (I) with a rate of increase or decrease of 90 to 100%, the total thickness of the cover tape (I) may be 40 to 50 μm, 42 μm or more but less than 50 μm, or 45 μm or more but less than 50 μm.

[0062] <Method for manufacturing cover tape (I)> The cover tape (I) according to the first embodiment can be manufactured by, for example, laminating the above-described layers so that the transmittance at wavelengths of 1300 to 1500 nm is 75% or more and the haze value is less than 30%. Hereinafter, one embodiment of a method for manufacturing a cover tape (I) comprising at least a base layer, an intermediate layer, and a heat seal layer as the cover tape (I) of the first embodiment will be described.

[0063] The manufacturing method according to the first embodiment includes laminating a base layer, an intermediate layer, and a heat-sealing layer to achieve a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%. In this case, from the viewpoint of easily achieving a transmittance of 75% or more, it is preferable to include selecting the thermoplastic resins for each layer so that the thermoplastic resins constituting the base layer, intermediate layer, and heat-sealing layer do not contain polyamide-based resins (step (1)). Furthermore, from the viewpoint of more easily controlling the transmittance to 75% or more, it is preferable to select the thermoplastic resins for each layer so that the intermediate layer contains an olefin-based resin. Furthermore, from the viewpoint of easily achieving a haze value of less than 30%, it is preferable to laminate the layers so that the layer surfaces are smooth, and it is more preferable to laminate so that the surface of the intermediate layer in contact with the heat-sealing layer is smooth.

[0064] In one embodiment, after the step (1), the method may include forming a heat seal layer (step (2)), applying a thermoplastic resin composition constituting an intermediate layer (hereinafter referred to as an "intermediate layer resin composition") to the base layer (step (3)), and laminating the base layer, the intermediate layer, and the heat seal layer (step (4)).

[0065] (Step (2)) The heat seal layer can be formed by, for example, a T-die casting method, an inflation method, etc. When an antistatic agent is blended into the heat seal layer, a resin composition containing the antistatic agent may be preblended in advance using a tumbler, and the resin composition may be formed into a film.

[0066] (Step (3)) Coating the intermediate layer resin composition on the substrate layer can be achieved by extruding the intermediate layer resin composition (preferably containing a polyolefin resin, particularly preferably LLDPE) from a T-die onto the surface of the substrate layer (preferably a biaxially oriented polyester film). If necessary, before coating the intermediate layer resin composition, an anchor coating agent (preferably a polyurethane adhesive) may be applied to the surface of the substrate layer, and the intermediate layer may be laminated onto the surface coated with the anchor coating agent. By extrusion-coating the molten intermediate layer resin composition onto the surface of the substrate layer and laminating the intermediate layer on the substrate layer, the surface of the intermediate layer that contacts the heat seal layer tends to be smooth, and the haze value can be easily controlled to less than 30%.

[0067] (Step (4)) When laminating the base layer, intermediate layer, and heat seal layer, it is preferable to sandwich laminate the heat seal layer formed in step (3) on the intermediate layer obtained in step (3).

[0068] (Step (5)) In a preferred embodiment, the method further includes laminating an antistatic layer on the heat seal layer (step (5)). When laminating the antistatic layer on the heat seal layer, it is preferable to apply the resin composition constituting the antistatic layer using, for example, a gravure coater, a reverse coater, a kiss coater, an air knife coater, a Mayer bar coater, a dip coater, or the like.

[0069] In one embodiment, the production method may include, after the step (1), forming a two-layer film consisting of an intermediate layer and a heat seal layer (step (6)), and laminating the two-layer film and the base layer (step (7)).

[0070] (Step (6)) To produce a two-layer film consisting of an intermediate layer and a heat-sealing layer, it is preferable to extrude the aforementioned resin composition for the intermediate layer (preferably a polyolefin resin, particularly preferably LLDPE) and the resin composition constituting the heat-sealing layer (hereinafter referred to as the "resin composition for the heat-sealing layer") from separate single-screw extruders and laminate them using a multi-manifold die. By laminating the intermediate layer and the heat-sealing layer into a two-layer film in this way, the surface of the intermediate layer that contacts the heat-sealing layer tends to be smooth, and the haze value can be easily controlled to less than 30%.

[0071] (Step (7)) In laminating the two-layer film and the base layer, it is preferable to apply an anchor coating agent (preferably a polyurethane adhesive) to the surface of the base layer (preferably a biaxially oriented polyester film) as needed, and then laminate the two-layer film onto the side coated with the anchor coating agent by a dry lamination method.

[0072] (Step (8)) After step (7), step (8) may further include laminating an antistatic layer on the surface of the heat seal layer. Step (8) may be performed by the same method as step (5) described above.

[0073] In one embodiment, the manufacturing method according to the first embodiment may include, after the step (1), forming a two-layer film consisting of a part of the intermediate layer and a heat seal layer (step (9)), coating the base layer with a resin composition that constitutes a part of the intermediate layer (step (10)), and laminating them so that the surface of the two-layer film on the intermediate layer side and the surface of the base layer on the intermediate layer side are in contact with each other (step (11)).

[0074] (Step (9)) To produce a two-layer film consisting of a part of the intermediate layer and a heat-sealing layer, it is preferred to extrude the resin composition (preferably a polyolefin-based resin, particularly preferably LLDPE) constituting a part of the intermediate layer and the resin composition for the heat-sealing layer from separate single-screw extruders and laminate them using a multi-manifold die.

[0075] (Step (10)) Coating the substrate layer with the resin composition that constitutes part of the intermediate layer is preferably carried out by extruding the resin composition (preferably a polyolefin resin, particularly preferably LLDPE) that constitutes part of the intermediate layer onto the surface of the substrate layer (preferably a biaxially oriented polyester film) through a T-die. Before coating the resin composition, an anchor coating agent (preferably a polyurethane adhesive) may be applied to the surface of the substrate layer, if necessary, and the intermediate layer may be laminated on the surface coated with the anchor coating agent. By combining steps (9) and (10), the surface of the intermediate layer that contacts the heat seal layer tends to be smooth, making it easier to control the haze value to less than 30%.

[0076] (Step (11)) After step (10), the two-layer film and the substrate layer are laminated together so that the surface of the intermediate layer of the two-layer film contacts the surface of the intermediate layer of the substrate layer (sand lamination). Step (12) may also include laminating an antistatic agent on the heat seal layer. Step (11) may be performed in the same manner as step (5).

[0077] The intermediate layer of the cover tape (I) obtained by the above steps (9) to (11) (or steps (9) to (12)) has a two-layer structure consisting of a layer formed by co-extrusion with the heat seal layer and a layer formed by sand lamination. The thickness of the layer formed by sand lamination is preferably 10 to 20 μm, from the viewpoints that the transmittance described above is likely to be 75% or more and the haze value is likely to be less than 30%.

[0078] In addition to the above-described steps, the manufacturing method according to the first embodiment may, if necessary, include antistatic treatment of the surface of the base layer of the cover tape (I) (the surface not in contact with the intermediate layer). Examples of antistatic agents include those described above, and preferred examples of these are also the same. The antistatic treatment can be carried out using a roll coater or lip coater using a gravure roll, a spray, or the like. Furthermore, in order to uniformly apply these antistatic agents, it is preferable to perform corona discharge treatment or ozone treatment on the film surface before the antistatic treatment, and corona discharge treatment is particularly preferable.

[0079] As described above, the cover tape (I) according to the first embodiment is resistant to moisture absorption even under high temperature and high humidity conditions. In one embodiment, the moisture absorption rate of the cover tape (I) under the following conditions is preferably 5,000 ppm by mass or less. In a preferred embodiment, the moisture absorption rate may be 4,500 ppm by mass or less, 4,000 ppm by mass or less, or 3,500 ppm by mass or less. <Conditions> As a pretreatment, the cover tape (I) is stored under dry conditions of 60°C / 20% RH for 12 hours. Subsequently, after storing under conditions of 60°C / 90% RH for 24 hours, the moisture absorption rate of the cover tape (I) is measured at a holding temperature of 280°C according to JIS K0068:2001 "Karl Fischer titration method, moisture evaporation-coulometric titration method."

[0080] [Uses] The cover tape (I) according to the first embodiment can be used as a cover tape (I) for electronic component packaging. The cover tape (I) according to the first embodiment has low moisture absorption under high temperature and high humidity conditions. Therefore, it can be used, for example, as a low-moisture-absorption cover tape (I) for electronic component packaging. Furthermore, the cover tape (I) according to the first embodiment has good visibility, so it can be used, for example, as a high-visibility cover tape (I) for electronic component packaging.

[0081] [Electronic Component Package (I)] Next, the electronic component package (I) will be described. A package containing electronic components, etc. (hereinafter referred to as "electronic component package") can be obtained, for example, by placing the electronic components, etc. in recesses in a carrier tape for storing the electronic components, etc., and then using a cover tape as a lid material, continuously heat-sealing both longitudinal edges of the cover tape using a heat iron or the like to package the components, and then winding the package onto a reel. Packaged in this form, the electronic components, etc. are stored and transported. The electronic component package (I) according to the first embodiment can be used to store and transport various electronic components, such as connectors, ICs, diodes, transistors, capacitors, resistors, and LEDs.

[0082] The electronic component package (I) is transported using holes called sprocket holes for transporting the carrier tape provided on the longitudinal edge of the carrier tape, while the cover tape (I) is intermittently peeled off, and the electronic components are removed while checking the presence, orientation, and position of the electronic components using a component mounting device, and then mounted on a substrate.

[0083] <Carrier Tape> The carrier tape (hereinafter referred to as "carrier tape (I)") included in the electronic component packaging body (I) according to the first embodiment is a strip-shaped material having a width of approximately 4 mm to 100 mm and having a recess for accommodating electronic components. When the cover tape (I) according to the first embodiment is used as a lid material for heat sealing, the material constituting the carrier tape (I) is not particularly limited, but carrier tapes containing polystyrene-based resins, polyester-based resins, and polycarbonate-based resins can be suitably used. The carrier tape (I) may be imparted with conductivity by kneading carbon black or carbon nanotubes into the resin, or may be kneaded with a surfactant-type antistatic agent such as a cationic, anionic, or nonionic agent, or a persistent antistatic agent such as polyether ester amide, or may be imparted with antistatic properties by coating the surface with a coating liquid in which a surfactant-type antistatic agent or a conductive material such as polypyrrole or polythiophene is dispersed in an organic binder such as an acrylic resin.

[0084] When storing or transporting electronic component packages, it is necessary to suppress moisture absorption of the electronic component package including the cover tape due to changes in temperature and humidity, and to prevent problems with the stored contents (electronic components) caused by this. Furthermore, the electronic component package is also required to be able to confirm the orientation and front / back of the enclosed electronic components from the cover tape side, and to be able to detect serial numbers printed on the surfaces of the electronic components from the cover tape side. The electronic component package (I) according to the first embodiment includes the aforementioned cover tape (I), making it less likely to absorb moisture even under high temperature and high humidity conditions. Therefore, problems with the electronic components caused by moisture absorption by the cover tape are also easily suppressed. Furthermore, the electronic component package (I) according to the first embodiment has good visibility, making it possible to check defects in the enclosed electronic components from the cover tape (I) side.

[0085] Furthermore, the electronic component packaging is inspected with an IR camera to detect defects in the enclosed electronic components and to recognize circuits printed on the electronic components, etc. The electronic component packaging (I) according to the first embodiment includes a cover tape that has high transmittance in the near-infrared wavelength range and a small haze value, and therefore has good visibility with an IR camera.

[0086] Another aspect of the first embodiment is a method for suppressing moisture absorption by a cover tape under high temperature and high humidity conditions and improving the visibility of the cover tape by controlling the transmittance of the cover tape at wavelengths of 1300 to 1500 nm to 75% or more and controlling the haze value to less than 30%. The method preferably further includes controlling the transmittance of the cover tape at wavelengths of 1200 to 1600 nm to 75% or more. Furthermore, the method preferably includes controlling the rate of increase or decrease of the transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, expressed by the following formula (1), to 90% or more: (T2 / T1) × 100(%) (1)

[0087] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the first embodiment is described below. [1] A cover tape (I) having a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%. [2] The cover tape (I) described in [1] has a transmittance of 75% or more at wavelengths of 1200 to 1600 nm. [3] The cover tape (I) described in [1] or [2] has a rate of increase or decrease of 90% or more between the transmittance (T2) at a wavelength of 1600 nm and the transmittance (T1) at a wavelength of 1200 nm, as expressed by the following formula (1): (T2 / T1) x 100(%)... (1) [4] The cover tape (I) described in any one of [1] to [3] does not contain a polyamide-based resin. [5] The cover tape (I) described in any one of [1] to [4] has at least a base layer, an intermediate layer, and a heat-seal layer laminated in this order, and the intermediate layer contains a polyolefin-based resin. [6] The cover tape (I) according to any one of [1] to [5], wherein at least a base material layer, an intermediate layer, and a heat seal layer are laminated in this order, and the intermediate layer does not contain a polyamide resin. [7] The cover tape (I) according to [5] or [6], wherein the heat seal layer has a thickness of less than 20 μm. [8] The cover tape (I) according to any one of [1] to [7], which is for use in an electronic component packaging. [9] An electronic component packaging (I) comprising the cover tape (I) according to any one of [1] to [8].

[0088] [Second Embodiment: Cover Tape (II)] The second embodiment of the present disclosure relates to a cover tape (II). The cover tape (II) according to the second embodiment has a transmittance of more than 80% at wavelengths of 1300 to 1500 nm. Wavelengths of 1300 to 1500 nm are light in the near-infrared wavelength range. Thus, the cover tape (II) according to the second embodiment, which has a transmittance of more than 80% in the near-infrared wavelength range, is less likely to absorb moisture even under high temperature and low humidity conditions. In other words, the cover tape (II) can solve the second problem. In the present disclosure, "a transmittance of more than 80% at wavelengths of 1300 to 1500 nm" means that the cover tape (II) has a transmittance of more than 80% at any wavelength within the wavelength range, which is different from an average transmittance of more than 80% in the wavelength range. <Method for measuring transmittance> As a measurement and analysis device, an ultraviolet-visible-near-infrared spectrophotometer (for example, manufactured by Shimadzu Corporation, product name "UV-3600") and a multipurpose large sample chamber (φ60 mm, with built-in integrating sphere; for example, manufactured by Shimadzu Corporation, product name "MPC-3100") are used. First, baseline correction is performed without the cover tape (II), and then the cover tape (II) is attached and the spectral transmittance at a wavelength of 1200 to 1600 nm is measured using an integrating sphere. In the present disclosure, the transmittance of the cover tape (II) is determined by rounding the transmittance measured by the above measurement method to one decimal place.

[0089] In one embodiment, from the viewpoint of easily obtaining a cover tape (II) with less moisture absorption under high temperature and low humidity conditions, the transmittance at wavelengths of 1300 to 1500 nm may be 83% or more, 85% or more, or even 88% or more. In one embodiment, the transmittance in the wavelength range may be 90% or more. Note that, from the viewpoint of easily obtaining a cover tape (II) with less moisture absorption under high temperature and low humidity conditions due to high transmittance at wavelengths of 1300 to 1500 nm, the upper limit of the transmittance in the wavelength range is not particularly limited. In the cover tape (II) according to the second embodiment, "a transmittance of more than 80% at wavelengths of 1300 to 1500 nm" is easily achieved, for example, when the resin components constituting the cover tape (II) do not contain a polyamide-based resin, when an intermediate layer containing an olefin-based resin is provided, and / or when a heat seal layer containing a styrene-based resin as a main component, as described below, is provided. In this disclosure, "polyamide-based resin" refers to a polyamide resin containing an aliphatic skeleton, commonly known as Nylon (registered trademark).

[0090] The cover tape (II) according to the second embodiment preferably has a transmittance of 84% or more at wavelengths of 1200 to 1600 nm, more preferably 85% or more. A cover tape (II) having a transmittance of 84% or more, more preferably 85% or more, in a wavelength range even wider than the wavelength range of 1300 to 1500 nm is preferred because it has less moisture absorption. In the present disclosure, "a transmittance of 84% or more at wavelengths of 1200 to 1600 nm" means that the transmittance of the cover tape (II) is 84% ​​or more at any wavelength within that wavelength range, which is different from an average transmittance of 84% or more within that wavelength range.

[0091] The transmittance at wavelengths of 1200 to 1600 nm can be measured by the same method as the transmittance measurement method described above. In one embodiment, the transmittance at wavelengths of 1200 to 1600 nm may be 86% or more, or may be 87% or more. Furthermore, from the viewpoint of obtaining a cover tape (II) that has low moisture absorption under high temperature and low humidity conditions, the upper limit is not particularly limited.

[0092] In one embodiment, the cover tape may have a change rate of 90% or more of the transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, as expressed by the following formula (1): (T2 / T1)×100(%) (1)

[0093] If the rate of change represented by the formula (1) is 90% or more, the cover tape (II) is likely to be less hygroscopic under high temperature and low humidity conditions. For example, when the transmittance (T1) at a wavelength of 1200 nm is 85%, the cover tape (II) preferably has a transmittance (T2) at a wavelength of 1600 nm of 76.5% or more. Furthermore, the cover tape (II) having a transmittance of 85% or more at wavelengths of 1200 to 1600 nm is preferred because it is likely to have a rate of change represented by the formula (1) of 90% or more.

[0094] The upper limit of the rate of change expressed by the formula (1) is not particularly limited as long as the effects of the present invention are achieved. The cover tape according to the second embodiment may also include a case where T1<T2, and therefore the rate of change may be 100% or more. In one embodiment, the rate of change may be 90 to 105%, or may be 95 to 102%.

[0095] For example, as in the case of cover tape II-7 shown in Comparative Example II-2 below, transmittance tends to gradually decrease as the wavelength shifts toward higher near-infrared wavelengths. In the case of cover tape II-7 shown in Comparative Example II-2, the transmittance at wavelengths of 1300 to 1500 nm is 80% or less, and the rate of change is less than 90%. Through studies by the present inventors, it has been found that cover tapes such as those in Comparative Example II-2 are prone to moisture absorption even under high temperatures and low humidity. The cover tape (II) according to the second embodiment has a high transmittance of over 80% at wavelengths of 1300 to 1500 nm, and the rate of change in transmittance over a wider wavelength range, i.e., the transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, is likely to be 90% or higher. Although the reason for this is unclear, such cover tape (II) is resistant to moisture absorption even under high temperatures and low humidity, making it less susceptible to problems caused by moisture absorption by the cover tape. Furthermore, the cover tape (II) according to the second embodiment is less likely to absorb moisture due to changes in temperature and humidity.

[0096] <Layer Structure> The cover tape (II) according to the second embodiment can have a multilayer structure in which a base layer, an intermediate layer, and a heat seal layer are laminated in this order. For each layer constituting the cover tape (II) according to the second embodiment, it is necessary to select a thermoplastic resin, additives, etc. so that the transmittance of the cover tape (II) at a wavelength of 1300 to 1500 nm is greater than 80%. In a preferred embodiment, from the viewpoint of easily achieving the above transmittance, each layer constituting the cover tape (II) does not contain a polyamide resin.

[0097] Below, we will describe an example of a cover tape (II) that has at least a base layer, an intermediate layer, and a heat seal layer and that easily achieves the transmittance requirements of the cover tape (II) according to the second embodiment, but the configuration of the cover tape (II) according to the second embodiment is not limited to the following.

[0098] <Base layer> The base layer is a layer containing a thermoplastic resin, and is preferably made of a film formed from a thermoplastic resin. The thermoplastic resin constituting the base layer is preferably selected from the viewpoint of easily achieving a transmittance of more than 80% at a wavelength of 1300 to 1500 nm and satisfying the mechanical properties required for the cover tape (II). Examples of such a base layer include the same ones as those described for the cover tape (I), and preferred examples are also the same.

[0099] The thickness of the base layer is generally set arbitrarily within the range of 5 to 50 μm, taking into consideration the mechanical properties of the cover tape (II). In the cover tape (II) according to the second embodiment, it is preferable to set the thickness of the base layer so that the transmittance at wavelengths of 1300 to 1500 nm is greater than 80%, or the transmittance at wavelengths of 1200 to 1600 nm is 85% or greater. From these viewpoints, the thickness of the base layer is preferably 10 to 30 μm, more preferably greater than 10 μm and 30 μm or less, and even more preferably 12 to 20 μm. In one embodiment, the thickness of the base layer may be greater than 10 μm and 20 μm or less, or may be 13 to 16 μm.

[0100] In one embodiment, at least one surface of the base layer may be surface-treated. Examples of the surface treatment include the same as those described for the cover tape (I), and preferred examples are also the same.

[0101] <Intermediate Layer> The intermediate layer is a thermoplastic resin layer laminated on one side of the substrate layer, optionally via an adhesive layer or anchor coat layer. The present inventors have found that the transmittance of the cover tape in the near-infrared wavelength range is easily affected by the thermoplastic resin constituting the intermediate layer. After further investigation, the present inventors have found that when the intermediate layer does not contain a polyamide-based resin, the transmittance at wavelengths of 1300 to 1500 nm is likely to be 80% or higher. Furthermore, from the viewpoint of also easily achieving a transmittance at wavelengths of 1200 to 1600 nm of 85% or higher, it has also been found that it is preferable for the intermediate layer to contain no polyamide-based resin but to contain a polyolefin-based resin.

[0102] Examples of polyolefin resins include the same ones as those explained for the cover tape (I), and preferred examples are also the same.

[0103] From the viewpoint of easily obtaining a cover tape (II) that has a transmittance of more than 80% at wavelengths of 1300 to 1500 nm and exhibits low moisture absorption under high temperature and low humidity conditions, the intermediate layer preferably contains only a polyolefin resin as a resin component, and more preferably contains only LLDPE. Furthermore, from the viewpoint of easily obtaining a cover tape (II) that exhibits low moisture absorption under high temperature and low humidity conditions, a multilayer structure in which two or more layers of the same type of polyolefin resin are laminated (preferably a multilayer structure in which two or more layers of polyethylene are laminated, more preferably a multilayer structure in which two or more layers of LLDPE are laminated) is preferred. Here, "the same type of polyolefin resin" means that the olefin units contained in the polyolefin resin are the same, although their molecular weights may be different. When the intermediate layer has a multilayer structure, the intermediate layer may be laminated directly on the substrate layer without an anchor coat layer interposed therebetween.

[0104] When the intermediate layer contains LLDPE, linear low density polyethylene (m-LLDPE) polymerized with a metallocene catalyst is preferred.

[0105] The m-LLDPE may be the same as those described for the cover tape (I), and the preferred examples are also the same.

[0106] In the cover tape, the thickness of the intermediate layer is generally 5 to 50 μm, preferably 10 to 40 μm. The thickness of the intermediate layer is generally set from the viewpoint of various physical properties such as the adhesive strength between the intermediate layer and the base layer and the peel strength during heat sealing. In the cover tape (II) according to the second embodiment, it is preferable to further control the thickness of the intermediate layer from the viewpoint of obtaining a cover tape (II) with low moisture absorption under high temperature and low humidity conditions by controlling the transmittance at a wavelength of 1300 to 1500 nm to more than 80%. In one embodiment, the thickness of the intermediate layer is preferably 10 to 40 μm, more preferably 13 to 38 μm. The thickness of the intermediate layer may also be 20 to 38 μm.

[0107] <Heat seal layer> The heat seal layer has heat sealability to the carrier tape, can be easily peeled off during use, contains a thermoplastic resin exhibiting easy peelability, and can be selected from the viewpoint that the transmittance of the cover tape (II) at a wavelength of 1300 to 1500 nm is likely to be more than 80%. Examples of such a heat seal layer include the same as those described for the cover tape (I), and preferred examples are also the same.

[0108] In one embodiment, the heat seal layer preferably contains a styrene-based resin as a primary component. In this case, the transmittance at wavelengths of 1300 to 1500 nm is likely to exceed 80%, resulting in a cover tape (II) with low moisture absorption under high temperature and low humidity conditions. In the present disclosure, "containing a styrene-based resin as a primary component" refers to a styrene-based resin content of more than 50% by mass relative to the total amount (100% by mass) of all resin components. The proportion of the styrene-based resin in the heat seal layer is preferably greater than 50% by mass and less than 100% by mass, more preferably 70 to 100% by mass, and particularly preferably greater than 70% by mass and less than 100% by mass. In a preferred embodiment, from the viewpoint of more easily obtaining a cover tape (II) with a transmittance at wavelengths of 1200 to 1600 nm of 84% or more (more preferably 85% or more, and even more preferably 90% or more), the heat seal layer more preferably contains at least one styrene-based resin selected from SB, SEBS, and SBC as a primary component.

[0109] The thickness of the heat seal layer is generally set from the viewpoint of heat sealing properties with the carrier tape. In the cover tape (II) according to the second embodiment, it is preferable to control the thickness of the heat seal layer from the viewpoint of obtaining a cover tape (II) with low moisture absorption under high temperature and low humidity conditions by controlling the transmittance at wavelengths of 1300 to 1500 nm to more than 80%. In one embodiment, the thickness of the heat seal layer is preferably 3 to 30 μm, more preferably 5 to 25 μm. In one embodiment, the thickness of the heat seal layer may be 3 to 25 μm.

[0110] In one embodiment, the heat seal layer may contain one or more antistatic agents, which will be described later. When the heat seal layer contains an antistatic agent, the heat seal layer has heat sealability and antistatic properties.

[0111] (Adhesive layer or anchor coat layer) In one embodiment, an adhesive layer or anchor coat layer can be provided between the intermediate layer and the base layer, or between the intermediate layer and the heat seal layer. When an adhesive layer or anchor coat layer is provided, examples of the adhesive layer or anchor coat layer can be the same as those described in the cover tape (I), and preferred examples are also the same.

[0112] In one embodiment, it is preferable to provide an anchor coat layer between the intermediate layer and the base layer.When the intermediate layer is laminated via the anchor coat layer, the polyolefin resin constituting the intermediate layer is preferably a single layer, and it is more preferable to have an intermediate layer structure consisting of base layer / anchor coat layer / polyolefin resin such as LLDPE.With such a structure, the transmittance is likely to be more than 80%, and the cover tape (II) is likely to have low moisture absorption under high temperature and low humidity conditions.

[0113] (Antistatic layer) The cover tape (II) according to the second embodiment can further comprise an antistatic layer. The antistatic layer can be provided on the heat seal layer and / or on the surface of the base layer that is not in contact with the intermediate layer. By providing an antistatic layer, the cover tape (II) can be provided with an antistatic effect, making it easier to prevent static breakdown of electronic components. As mentioned above, if the heat seal layer contains an antistatic agent, it is not necessary to provide an antistatic layer on the heat seal layer.

[0114] The antistatic layer is a layer containing an antistatic agent.The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape and easily achieving the transmittance described above.The antistatic agent can be exemplified by the same as those described in the cover tape (I), and the preferred examples are also the same.

[0115] The antistatic layer may further contain the antistatic agent and a binder resin. Examples of the binder resin include those described for the cover tape (I), and preferred examples are also the same. From the viewpoint of easily controlling the transmittance to more than 80% at wavelengths of 1300 to 1500 nm, it is preferable that the binder resin does not contain a polyamide resin.

[0116] When the cover tape (II) according to the second embodiment has an antistatic layer, it preferably contains at least one selected from ionic liquid, ATO, and alumina oxide, from the viewpoint that the transmittance at wavelengths of 1300 to 1500 nm is likely to be greater than 80% and the transmittance at wavelengths of 1200 to 1600 nm is likely to be 84% or more. Furthermore, when the above-mentioned preferred antistatic agent is blended, the proportion of the antistatic agent is preferably 90% by mass or less relative to the total mass of the resin composition constituting the antistatic layer.

[0117] The thickness of the antistatic layer is preferably 0.01 to 2.0 μm from the viewpoint of easily achieving both antistatic properties and the above-mentioned transmittance.

[0118] (Total Thickness of Cover Tape (II)) The total thickness of the cover tape (II) according to the second embodiment is preferably 40 to 65 μm from the viewpoint of easily achieving the various physical properties required for the cover tape (II) and easily achieving a transmittance of more than 80% at a wavelength of 1300 to 1500 nm. From the viewpoint of easily obtaining a cover tape with the aforementioned increase / decrease rate of 90 to 100%, the total thickness of the cover tape (II) may be 40 to 50 μm, 42 μm or more but less than 50 μm, or 45 μm or more but less than 50 μm.

[0119] <Method for manufacturing cover tape (II)> The cover tape (II) according to the second embodiment can be manufactured by, for example, laminating the above-described layers so that the transmittance at wavelengths of 1300 to 1500 nm is greater than 80%. Hereinafter, one embodiment of a method for manufacturing a cover tape (II) comprising at least a base layer, an intermediate layer, and a heat seal layer will be described as the cover tape (II) according to the second embodiment.

[0120] The manufacturing method according to the second embodiment includes laminating a base layer, an intermediate layer, and a heat-sealing layer to achieve a transmittance of more than 80% at wavelengths of 1300 to 1500 nm. In this case, from the viewpoint of easily achieving a transmittance of more than 80%, it is preferable to include selecting the thermoplastic resins of each layer so that the thermoplastic resins constituting the base layer, intermediate layer, and heat-sealing layer do not contain polyamide-based resins (step (1)). Furthermore, from the viewpoint of more easily controlling the transmittance to more than 80%, it is preferable in step (1) to select the thermoplastic resins of each layer so that the intermediate layer contains an olefin-based resin and the heat-sealing layer contains a styrene-based resin as a main component.

[0121] In one embodiment, after the step (1), the method may include forming a heat seal layer (step (2)), applying a thermoplastic resin composition constituting an intermediate layer (hereinafter referred to as an "intermediate layer resin composition") to the base layer (step (3)), and laminating the base layer, the intermediate layer, and the heat seal layer (step (4)).

[0122] (Step (2)) As a method for forming the heat seal layer, the same methods as those described in the method for producing the cover tape (I) can be exemplified, and preferred examples are also the same.

[0123] (Step (3)) Examples of coating the intermediate layer resin composition on the base material layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0124] (Step (4)) Examples of laminating the base material layer, intermediate layer, and heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0125] (Step (5)) In a preferred embodiment, the method further includes laminating an antistatic layer on the heat seal layer (step (5)). Examples of laminating an antistatic layer on the heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0126] In one embodiment, the production method may include, after the step (1), forming a two-layer film consisting of an intermediate layer and a heat seal layer (step (6)), and laminating the two-layer film and the base layer (step (7)).

[0127] (Step (6)) As examples of the production of a two-layer film consisting of an intermediate layer and a heat seal layer, the same can be mentioned as those explained in the production method of the cover tape (I), and the preferred examples are also the same.

[0128] (Step (7)) Examples of laminating the two-layer film and the base layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0129] (Step (8)) After step (7), step (8) may further include laminating an antistatic layer on the surface of the heat seal layer. Step (8) may be performed by the same method as step (5) described above.

[0130] In one embodiment, the production method may include, after the step (1), forming a two-layer film consisting of a part of the intermediate layer and a heat seal layer (step (9)), coating the base layer with a resin composition that constitutes a part of the intermediate layer (step (10)), and laminating them so that the surface of the two-layer film on the intermediate layer side and the surface of the base layer on the intermediate layer side are in contact with each other (step (11)).

[0131] (Step (9)) Examples of the method for producing a two-layer film consisting of a part of the intermediate layer and the heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0132] (Step (10)) Examples of coating the base layer with the resin composition that constitutes part of the intermediate layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0133] (Step (11)) After step (10), the two-layer film and the substrate layer are laminated together so that the surface of the intermediate layer of the two-layer film contacts the surface of the intermediate layer of the substrate layer (sand lamination). Step (12) may also include laminating an antistatic agent on the heat seal layer. Step (11) may be performed in the same manner as step (5).

[0134] The intermediate layer of the cover tape obtained by the above steps (9) to (11) (or steps (9) to (12)) has a two-layer structure consisting of a layer formed by co-extrusion with the heat seal layer and a layer formed by sand lamination. The thickness of the layer formed by sand lamination is preferably 10 to 20 μm, from the viewpoint of easily achieving the aforementioned transmittance of more than 80%.

[0135] In addition to the above-described steps, the manufacturing method according to this embodiment may, if necessary, include antistatic treatment on the surface of the base layer of the cover tape (II) (the surface not in contact with the intermediate layer). Examples of antistatic agents include those described above, and preferred examples thereof are also the same. The antistatic treatment can be carried out using a roll coater or lip coater using a gravure roll, a spray, or the like. Furthermore, in order to uniformly apply these antistatic agents, it is preferable to perform corona discharge treatment or ozone treatment on the film surface before the antistatic treatment, and corona discharge treatment is particularly preferable.

[0136] [Use] The cover tape (II) according to the second embodiment can be used as a cover tape (II) for an electronic component package.

[0137] As described above, the cover tape (II) according to the second embodiment is resistant to moisture absorption even under high temperature and low humidity conditions. In one embodiment, the moisture absorption rate of the cover tape (II) under the following conditions is preferably 1500 mass ppm or less, more preferably 1400 mass ppm or less, and even more preferably 1300 mass ppm or less. <Measurement conditions> After storing the cover tape (II) under dry conditions of 60°C / 20% RH for 12 hours, the moisture absorption rate of the cover tape (II) is measured at a holding temperature of 280°C by Karl Fischer titration in accordance with the "moisture evaporation-coulometric titration method" of JIS K0068:2001.

[0138] The cover tape (II) according to the second embodiment has low moisture absorption under high temperature and low humidity conditions. Such a cover tape (II) is also likely to absorb less moisture due to humidity fluctuations, and can therefore be used, for example, as a low moisture absorption cover tape (II) for electronic component packaging.

[0139] [Electronic Component Packaging Body (II)] Next, the electronic component packaging body (II) will be described. The details of the electronic component packaging body can be exemplified as those of the electronic component packaging body (I), and preferred examples are also the same. When storing or transporting the electronic component packaging body, it is stored or transported under conditions with minimal temperature and humidity changes in order to avoid moisture absorption of the electronic component packaging body including the cover tape due to temperature and humidity changes and resulting problems with the stored items (electronic components). However, as described above, according to the studies of the present inventors, moisture absorption of the cover tape can occur even under high temperature and low humidity conditions, so a cover tape that is resistant to moisture absorption even under low humidity conditions is required. The electronic component packaging body (II) according to the second embodiment includes the above-mentioned cover tape (II), and therefore is resistant to moisture absorption even under high temperature and low humidity conditions. Therefore, problems with electronic components caused by moisture absorption of the cover tape are also easily suppressed.

[0140] The electronic component package (II) is transported using holes called sprocket holes for transporting the carrier tape provided on the longitudinal edge of the carrier tape (II), while the cover tape (II) is intermittently peeled off, and the electronic components are removed while checking the presence, orientation, and position of the electronic components using a component mounting device, and then mounted on a substrate.

[0141] Examples of the carrier tape (II) contained in the electronic component packaging body (II) according to the second embodiment include the same as the above-mentioned carrier tape (I), and preferred examples are also the same.

[0142] Furthermore, the electronic component package is inspected by an IR camera through the cover tape to detect defects in the electronic components contained therein and to recognize circuits printed on the electronic components, etc. The cover tape (II) according to the second embodiment has high transmittance in the near-infrared range, and therefore has good visibility with an IR camera.

[0143] Another embodiment of the second embodiment is a method for suppressing moisture absorption of a cover tape under high temperature and low humidity conditions by controlling the transmittance of the cover tape at wavelengths of 1300 to 1500 nm to more than 80%. The method preferably further includes controlling the transmittance of the cover tape at wavelengths of 1200 to 1600 nm to 84% or more. Furthermore, the method preferably includes controlling the rate of increase or decrease of the transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, expressed by the following formula (1), to 90% or more: (T2 / T1) × 100(%) (1)

[0144] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the second embodiment is described below. <1> Cover tape (II) having a transmittance of more than 80% at wavelengths of 1300 to 1500 nm. <2> Cover tape (II) according to <1> having a transmittance of 84% or more at wavelengths of 1200 to 1600 nm. <3> Cover tape (II) according to <1> or <2> having a rate of increase or decrease of 90% or more between the transmittance (T2) at a wavelength of 1600 nm and the transmittance (T1) at a wavelength of 1200 nm, as expressed by the following formula (1): (T2 / T1) x 100(%) (1) <4> Cover tape (II) according to any one of <1> to <3>, which does not contain a polyamide-based resin. <5> Cover tape (II) according to any one of <1> to <4>, which has at least a base layer, an intermediate layer, and a heat-seal layer laminated in this order, and which contains a polyolefin-based resin. <6> The cover tape (II) according to any one of <1> to <4>, wherein at least a base material layer, an intermediate layer, and a heat seal layer are laminated in this order, and the intermediate layer does not contain a polyamide-based resin. <7> The cover tape (II) according to <5> or <6>, wherein the heat seal layer contains a styrene-based resin as a main component. <8> The cover tape (II) according to any one of <1> to <7>, which is for use in an electronic component packaging. <9> An electronic component packaging (II) comprising the cover tape (II) according to any one of <1> to <8>.

[0145] [Third Embodiment: Cover Tape (III)] A third embodiment of the present disclosure relates to a cover tape (III). The cover tape (III) according to the third embodiment has a moisture absorption rate (a) of 1,500 mass ppm or less, measured under the following conditions. <Conditions> After storing the cover tape (III) under dry conditions of 60°C / 20% RH for 12 hours, the moisture absorption rate (a) of the cover tape (III) is measured at a holding temperature of 280°C according to JIS K0068:2001 "Karl Fischer titration method, moisture evaporation-coulometric titration method."

[0146] The moisture absorption rate (a) is an index showing the moisture absorption rate (a) of the cover tape after storing the cover tape in a high-temperature, low-humidity environment for 12 hours. Thus, the cover tape (III) according to the third embodiment, in which the moisture absorption rate (a) measured under the above conditions is 1500 mass ppm or less, has high transmittance in the near-infrared wavelength range. Such a cover tape (III) also tends to have good visibility in near-infrared camera inspection (hereinafter sometimes referred to as "IR camera inspection"). In other words, the cover tape (III) can solve the third problem. In the present disclosure, "transmittance in the near-infrared wavelength range" (hereinafter referred to as "near-infrared transmittance") includes the transmittance of near-infrared light with a wavelength of 1200 to 1600 nm.

[0147] In one embodiment, the moisture absorption rate (a) measured under the above conditions (hereinafter referred to as "moisture absorption rate (a)") is preferably 1400 mass ppm or less, more preferably 1300 mass ppm or less, and even more preferably 1250 mass ppm or less, from the viewpoint that the transmittance in the near-infrared wavelength range is likely to be higher and the visibility in IR camera inspection is likely to be good. Note that, since a lower moisture absorption rate (a) makes it easier to obtain a cover tape (III) with high near-infrared transmittance, the lower limit of the moisture absorption rate (a) is not particularly limited.

[0148] In the cover tape (III) according to the third embodiment, the "moisture absorption rate (a) of 1500 mass ppm or less" is easily achieved, for example, when the resin components constituting the cover tape (III) do not contain polyamide-based resin. Furthermore, when the cover tape (III) according to the third embodiment has a layer structure in which a base layer, an intermediate layer, and a heat-seal layer are laminated in this order, as described below, the moisture absorption rate (a) is easily achieved to 1500 mass ppm or less when the intermediate layer does not contain polyamide-based resin, or when the intermediate layer contains a polyolefin-based resin and / or the heat-seal layer contains a styrene-based resin as a main component, as described below. As a result, a cover tape (III) with high transmittance in the near-infrared wavelength range is easily obtained. In this disclosure, "polyamide-based resin" refers to a polyamide resin containing an aliphatic skeleton, commonly known as Nylon (registered trademark).

[0149] <Layer structure> The cover tape (III) according to the third embodiment can have a multilayer structure in which a base layer, an intermediate layer, and a heat seal layer are laminated in this order. Each layer constituting the cover tape (III) according to this embodiment must contain a thermoplastic resin, additives, etc. selected so that the moisture absorption rate (a) of the cover tape (III) is 1500 mass ppm or less. In a preferred embodiment, in order to easily achieve the moisture absorption rate (a) requirement, each layer constituting the cover tape (III) does not contain a polyamide resin such as nylon (registered trademark).

[0150] Below, we will describe an example of a cover tape (III) that has at least a base layer, an intermediate layer, and a heat seal layer and that is likely to achieve the moisture absorption rate (a) requirement of the third embodiment, but the configuration of the cover tape (III) related to the third embodiment is not limited to the following.

[0151] <Base material layer> Base material layer is a layer containing thermoplastic resin, and is preferably made of a film formed from thermoplastic resin.As the thermoplastic resin constituting base material layer, it is preferable to select from the viewpoint that the moisture absorption rate (a) of cover tape (III) is easily 1500 mass ppm or less, and the mechanical properties required for cover tape (III) are satisfied.As such base material layer, the same as those described in cover tape (I) can be exemplified, and preferred examples are also the same.

[0152] The thickness of the substrate layer is generally set arbitrarily within the range of 5 to 50 μm, taking into consideration the mechanical properties of the cover tape (III). In the cover tape (III) according to the third embodiment, it is preferable to set the thickness of the substrate layer so that the moisture absorption rate (a) is 1500 mass ppm or less. From these viewpoints, the thickness of the substrate layer is preferably 10 to 30 μm, more preferably 12 to 20 μm. In one embodiment, the thickness of the substrate layer may be greater than 10 μm and less than 20 μm, or may be 13 to 16 μm.

[0153] In one embodiment, at least one surface of the base layer may be surface-treated. Examples of the surface treatment include the same as those described for the cover tape (I), and preferred examples are also the same.

[0154] <Intermediate Layer> The intermediate layer is a thermoplastic resin layer laminated on one side of the substrate layer, optionally via an adhesive layer or anchor coat layer. The present inventors have found that the moisture absorption rate (a) of the cover tape is easily affected by the thermoplastic resin constituting the intermediate layer. As a result of further investigation, the present inventors have found that when the intermediate layer does not contain a polyamide-based resin, the moisture absorption rate (a) is likely to be 1500 mass ppm or less, and a cover tape (III) with high transmittance in the near-infrared wavelength range is easily obtained. Furthermore, they have also found that from the viewpoint of easily obtaining a cover tape (III) with a lower moisture absorption rate (a) and a transmittance of 85% or more in the wavelength range of 1200 to 1600 nm, it is preferable that the intermediate layer does not contain a polyamide-based resin and contains a polyolefin-based resin.

[0155] Examples of polyolefin resins include the same ones as those explained for the cover tape (I), and preferred examples are also the same.

[0156] From the viewpoint of easily obtaining a cover tape (III) having a moisture absorption rate (a) of 1500 mass ppm or less and having high transmittance in the near-infrared wavelength range, it is preferable that the intermediate layer has a single-layer structure made of one type of polyolefin resin (preferably a single-layer structure made of polyethylene, more preferably a single-layer structure made of LLDPE). Here, "the same type of polyolefin resin" means that the olefin units contained in the polyolefin resin are the same, and the molecular weights, etc., may be different.

[0157] When the intermediate layer comprises LLDPE, it is preferably a metallocene-catalyzed linear low density polyethylene (m-LLDPE).

[0158] The m-LLDPE may be the same as those described for the cover tape (I), and the preferred examples are also the same.

[0159] In the cover tape, the thickness of the intermediate layer is generally 5 to 50 μm, preferably 10 to 40 μm. The thickness of the intermediate layer is generally set from the viewpoint of various physical properties such as the adhesive strength between the intermediate layer and the base layer and the peel strength during heat sealing. In the cover tape (III) according to the third embodiment, it is preferable to control the thickness of the intermediate layer by controlling the moisture absorption rate (a) to 1500 mass ppm or less in order to obtain a cover tape (III) with high near-infrared transmittance. In one embodiment, the thickness of the intermediate layer is preferably 10 to 40 μm, more preferably 19 to 38 μm.

[0160] <Heat seal layer> The heat seal layer has heat sealability to the carrier tape, and can be easily peeled off when used, and contains a thermoplastic resin showing easy peelability, and can be selected from the viewpoint that the moisture absorption rate (a) of the cover tape (III) is likely to be 1500 mass ppm or less. Examples of such a heat seal layer can be the same as those described in the cover tape (I), and preferred examples are also the same.

[0161] In one embodiment, the heat seal layer preferably contains a styrene-based resin as a main component. In this case, the moisture absorption rate (a) is likely to be 1500 mass ppm or less, and as a result, a cover tape (III) having high transmittance in the near-infrared wavelength range is likely to be obtained. In a preferred embodiment, the heat seal layer more preferably contains at least one styrene-based resin selected from SB, SEBS, and SBC as a main component.

[0162] The thickness of the heat seal layer is generally set from the viewpoint of heat sealability with the carrier tape. In the cover tape (III) according to the third embodiment, in addition to heat sealability, it is preferable to control the thickness of the heat seal layer from the viewpoint of obtaining a cover tape (III) with high near-infrared transmittance by controlling the moisture absorption rate (a) to 1500 mass ppm or less. In one embodiment, the thickness of the heat seal layer is preferably 3 to 20 μm, more preferably 5 to 10 μm. In one embodiment, the thickness of the heat seal layer may be 3 to 25 μm.

[0163] In one embodiment, the heat seal layer may contain one or more antistatic agents, as described below. By including an antistatic agent in the heat seal layer, the heat seal layer becomes a layer having heat sealability and antistatic properties. The antistatic agent may be conductive fine particles with low near-infrared absorption.

[0164] (Adhesive layer or anchor coat layer) In one embodiment, an adhesive layer or anchor coat layer can be provided between the intermediate layer and the base layer, or between the intermediate layer and the heat seal layer. When an adhesive layer or anchor coat layer is provided, examples of the adhesive layer or anchor coat layer can be the same as those described in the cover tape (I), and preferred examples are also the same.

[0165] In one embodiment, it is preferable to provide an anchor coat layer between the intermediate layer and the base layer.When the intermediate layer is laminated via the anchor coat layer, the polyolefin resin constituting the intermediate layer is preferably a single layer, and more preferably the intermediate layer is made up of a base layer / anchor coat layer / polyethylene resin such as low-density polyethylene.If this configuration is adopted, the moisture absorption rate (a) is likely to be low, and the cover tape (III) described later is likely to have a small haze value.

[0166] (Antistatic Layer) The cover tape (III) according to the third embodiment may further comprise an antistatic layer. The antistatic layer may be provided on the heat seal layer and / or on the surface of the base layer that is not in contact with the intermediate layer. By providing an antistatic layer, the cover tape (III) can be provided with an antistatic effect, making it easier to prevent static breakdown of electronic components. As mentioned above, if the heat seal layer contains an antistatic agent, an antistatic layer may not be provided on the heat seal layer.

[0167] The antistatic layer is a layer containing an antistatic agent.The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape and easily achieving the moisture absorption rate (a) described above.The antistatic agent can be exemplified by the same as those described in the cover tape (I), and the preferred examples are also the same.

[0168] Furthermore, the antistatic layer can contain the antistatic agent and a binder resin. Examples of the binder resin include the same as those described in the cover tape (I), and preferred examples are also the same. In addition, from the viewpoint of easily controlling the moisture absorption rate (a) of the cover tape (III) to 1500 mass ppm or less, it is preferable that the binder resin does not contain a polyamide resin.

[0169] When the cover tape (III) according to the third embodiment has an antistatic layer, it preferably contains at least one selected from an ionic liquid, ATO, and alumina oxide. From the viewpoint of near-infrared transmittance, an antistatic agent with low near-infrared absorption function may be selected, and its blending amount may be controlled. In one embodiment, aluminum oxide may be included as the antistatic agent. Furthermore, when the above-mentioned preferred antistatic agent is blended, the proportion of the antistatic agent is preferably 90% by mass or less relative to the total mass of the resin composition constituting the antistatic layer.

[0170] The thickness of the antistatic layer is preferably 0.01 to 2.0 μm from the viewpoint of easily achieving both antistatic properties and the above-mentioned transmittance.

[0171] (Total thickness of cover tape (III)) The total thickness of the cover tape (III) according to the third embodiment is preferably 40 to 65 μm, more preferably 45 to 65 μm, from the viewpoint that it is easy to achieve the physical properties required for the cover tape (III) and that the moisture absorption rate (a) is easy to be 1500 mass ppm or less.

[0172] (Haze Value) In one embodiment, from the viewpoint of improving visibility in camera inspection, the haze value of the cover tape (III) is preferably less than 25%, more preferably 24% or less, and particularly preferably 23% or less.

[0173] <Manufacturing method of cover tape (III)> The cover tape (III) according to the third embodiment can be manufactured by, for example, laminating the above-described layers so that the moisture absorption rate (a) is 1500 mass ppm or less. Hereinafter, one embodiment of a manufacturing method of the cover tape (III) according to the third embodiment, which includes at least a base layer, an intermediate layer, and a heat seal layer, will be described.

[0174] The manufacturing method according to the third embodiment includes laminating a base layer, an intermediate layer, and a heat seal layer to obtain a cover tape (III) having a moisture absorption rate (a) of 1500 mass ppm or less. In this case, from the viewpoint of easily achieving a moisture absorption rate (a) of 1500 mass ppm or less, it is preferable to include selecting the thermoplastic resins of each layer so that the thermoplastic resins constituting the base layer, intermediate layer, and heat seal layer do not contain polyamide-based resins (step (1)). Furthermore, from the viewpoint of more easily controlling the moisture absorption rate (a) to 1500 mass ppm or less, it is preferable to select the thermoplastic resins of each layer so that the intermediate layer contains an olefin-based resin and the heat seal layer contains a styrene-based resin as a main component in step (1).

[0175] In one embodiment, after step (1), the process may include forming a heat seal layer (step (2)), applying a thermoplastic resin composition constituting an intermediate layer (hereinafter referred to as an "intermediate layer resin composition") to the base layer (step (3)), and laminating the base layer, intermediate layer, and heat seal layer (step (4)).

[0176] (Step (2)) As a method for forming the heat seal layer, the same methods as those described in the method for producing the cover tape (I) can be exemplified, and preferred examples are also the same.

[0177] (Step (3)) Examples of coating the intermediate layer resin composition on the base material layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0178] (Step (4)) Examples of laminating the base material layer, intermediate layer, and heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0179] (Step (5)) In a preferred embodiment, the method further includes laminating an antistatic layer on the heat seal layer (step (5)). Examples of laminating an antistatic layer on the heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0180] In one embodiment, the production method may include, after the step (1), forming a two-layer film consisting of an intermediate layer and a heat-sealing layer (step (6)), and laminating the two-layer film and the base layer (step (7)).

[0181] (Step (6)) As examples of the production of a two-layer film consisting of an intermediate layer and a heat seal layer, the same can be mentioned as those explained in the production method of the cover tape (I), and the preferred examples are also the same.

[0182] (Step (7)) Examples of laminating the two-layer film and the base layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0183] (Step (8)) After step (7), it is preferable to further include laminating an antistatic layer on the surface of the heat seal layer (step (8)). Step (8) can be performed by the same method as in step (5) described above.

[0184] In one embodiment, the production method may include, after the step (1), forming a two-layer film composed of a part of the intermediate layer and the heat seal layer (step (9)), coating the base layer with a resin composition that constitutes a part of the intermediate layer (step (10)), and laminating them so that the surface of the two-layer film on the intermediate layer side and the surface of the base layer on the intermediate layer side are in contact with each other (step (11)).

[0185] (Step (9)) Examples of the method for producing a two-layer film consisting of a part of the intermediate layer and the heat seal layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0186] (Step (10)) Examples of coating the base layer with the resin composition that constitutes part of the intermediate layer include those described in the method for producing the cover tape (I), and preferred examples are also the same.

[0187] (Step (11)) After step (10), the two-layer film and the substrate layer are laminated together so that the surface of the intermediate layer of the two-layer film contacts the surface of the intermediate layer of the substrate layer (sand lamination). It is also preferable to include laminating an antistatic layer on the heat seal layer (step (12)). Step (12) can be performed in the same manner as step (5).

[0188] The cover tape (III) obtained by the above steps (9) to (11) (or steps (9) to (12)) has a two-layer structure in which the intermediate layer is formed by co-extrusion with the heat seal layer and a layer formed by sand lamination. The thickness of the layer formed by sand lamination is preferably 10 to 20 μm from the viewpoint of the moisture absorption rate (a) of the cover tape (III).

[0189] In addition to the above-described steps, the manufacturing method according to the third embodiment may, if necessary, include antistatic treatment of the surface of the base layer of the cover tape (III) (the surface not in contact with the intermediate layer). Examples of antistatic agents include those described above. Among these, from the viewpoint of increasing near-infrared transmittance, it is preferable to select an antistatic agent with low near-infrared absorption function, and it is also preferable to control the amount of the agent blended. The antistatic treatment can be carried out using a roll coater or lip coater using a gravure roll, a spray, or the like. Furthermore, in order to apply these antistatic agents uniformly, it is preferable to perform corona discharge treatment or ozone treatment on the film surface before the antistatic treatment, with corona discharge treatment being particularly preferable.

[0190] [Use] The cover tape (III) according to the third embodiment can be used as a cover tape (III) for an electronic component package.

[0191] As described above, the cover tape (III) according to the third embodiment exhibits the effect of high near-infrared transmittance. In the present disclosure, "high near-infrared transmittance" includes the cover tape (III) having a transmittance of more than 80% at wavelengths of 1300 to 1500 nm. Furthermore, from the viewpoint of improving visibility in camera inspections, particularly IR camera inspections, the cover tape (III) may also include a transmittance of 85% or more at wavelengths of 1200 to 1600 nm. Here, "the cover tape (III) has a transmittance of more than 80% at wavelengths of 1300 to 1500 nm" means that the cover tape (III) has a transmittance of more than 80% at any wavelength within the wavelength range, which is different from an average transmittance of more than 80%. The same applies to the transmittance at wavelengths of 1200 to 1600 nm.

[0192] The transmittance of the cover tape (III) in the near-infrared wavelength range can be measured under the following conditions. <Method for Measuring Transmittance> As a measurement and analysis device, an ultraviolet-visible-near-infrared spectrophotometer (for example, manufactured by Shimadzu Corporation, product name "UV-3600") and a multipurpose large sample chamber (φ60 mm, with built-in integrating sphere; for example, manufactured by Shimadzu Corporation, product name "MPC-3100") are used. First, baseline correction is performed without the cover tape (III), and then the cover tape (III) is attached and the spectral transmittance at wavelengths of 1200 to 1600 nm is measured using an integrating sphere.

[0193] The cover tape (III) according to the third embodiment has high transmittance in the near-infrared wavelength range, and can therefore be used as a visibility-improving cover tape (III) for electronic component packaging. Furthermore, since the moisture absorption rate (a) is low, at 1500 mass ppm or less, the cover tape (III) can also be used as a low-moisture-absorption cover tape (III) for electronic component packaging.

[0194] [Electronic component packaging body (III)] Next, the electronic component packaging body (III) will be described. The details of the electronic component packaging body can be exemplified as the same as those of the electronic component packaging body (I), and preferred examples are also the same. The electronic component packaging body (III) according to the third embodiment includes the cover tape (III) according to the third embodiment, and therefore tends to have good visibility in near-infrared camera inspection. Furthermore, the electronic component packaging body (III) according to the third embodiment includes the cover tape (III) described above, and therefore is less likely to absorb moisture even under high temperature and low humidity conditions. Therefore, problems with electronic components caused by moisture absorption by the cover tape are also likely to be suppressed.

[0195] The electronic component package (III) is transported using holes called sprocket holes for transporting the carrier tape provided on the longitudinal edge of the carrier tape (III), while the cover tape (III) is intermittently peeled off, and the electronic components are removed while checking the presence, orientation, and position of the electronic components, etc. using a component mounting device, and are then mounted on a substrate.

[0196] Examples of the carrier tape (III) included in the electronic component packaging body (III) according to the third embodiment include the same as the above-mentioned carrier tape (I), and preferred examples are also the same.

[0197] Another embodiment of the third embodiment is a method for improving the transmittance of a cover tape in the near-infrared wavelength range by controlling the moisture absorption rate (a) of the cover tape, measured under the above-mentioned conditions, to 1500 mass ppm or less. The method may be a method for improving the transmittance of the cover tape to more than 80% in the wavelength range of 1300 to 1500 nm. Alternatively, the method may be a method for improving the transmittance of the cover tape to 84% or more in the wavelength range of 1200 to 1600 nm.

[0198] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of the third embodiment is set forth below. "1" A cover tape (III) having a moisture absorption rate (a) of 1500 mass ppm or less, measured under the following conditions: <Conditions> After storing the cover tape (III) under dry conditions of 60°C / 20% RH for 12 hours, the moisture absorption rate (a) of the cover tape (III) is measured at a holding temperature of 280°C according to the "Karl Fischer titration method, moisture evaporation-coulometric titration method" of JIS K0068:2001. "2" A cover tape (III) according to "1" having a haze value of less than 25%. "3" A cover tape (III) according to "1" or "2" that does not contain a polyamide-based resin. "4" A cover tape (III) according to any one of "1" to "3", in which at least a base layer, an intermediate layer, and a heat-seal layer are laminated in this order, and the intermediate layer contains a polyolefin-based resin. "5" A cover tape (III) according to any one of "1" to "4", which comprises at least a base material layer, an intermediate layer, and a heat seal layer laminated in this order, and wherein the intermediate layer does not contain a polyamide-based resin. "6" A cover tape (III) according to "4" or "5", which comprises a styrene-based resin as a main component of the heat seal layer. "7" A cover tape (III) according to any one of "1" to "6", which is for use in an electronic component packaging. "8" An electronic component packaging (III) comprising the cover tape (III) according to any one of "1" to "7".

[0199] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0200] [First Embodiment: Cover Tape (I)] <Manufacture of Cover Tapes I-1 to I-7> The thermoplastic resins listed in Table 1 were selected as the thermoplastic resins constituting each layer. The thickness of each layer was determined as listed in Table 1. Subsequently, the substrate layer, intermediate layer, heat seal layer, and antistatic layer were laminated in this order according to the aforementioned steps (2) to (5). Specifically, the heat seal layer resin composition was extruded using a single-screw extruder by the T-die method to form a heat seal layer. Next, the formed heat seal layer and the substrate layer (PET film) were extrusion-sand laminated with the molten intermediate layer resin composition to laminate the substrate layer, intermediate layer, and heat seal layer in this order. Furthermore, an antistatic layer was coated on the heat seal layer and dried to obtain cover tapes I-1 to I-7. For cover tapes I-2 to I-6, an anchor coat layer (urethane adhesive) was provided on the substrate layer, and then an intermediate layer was laminated on the surface of the anchor coat layer.

[0201] <Production of Cover Tapes I-8 to I-9> The thermoplastic resins listed in Table 1 were selected as the thermoplastic resins constituting each layer, and the thickness of each layer was determined as listed in Table 1. Then, the substrate layer, intermediate layer, heat seal layer, and antistatic layer were laminated according to the above-mentioned steps (2) to (5). Cover tapes I-8 to I-9 were produced in the same manner as cover tapes I-1 to I-7, except that anchor coat layers were provided between the substrate layer and the intermediate layer, and between the intermediate layer and the heat seal layer.

[0202]

[0203] The components listed in Table 1 are as follows: <Base layer> PET: biaxially stretched polyethylene terephthalate film <Intermediate layer> m-LLDPE Polyamide resin (nylon) <Heat seal layer> Styrene-based resin 1: resin composition containing SBC and SB Styrene-based resin 2: SEBS Styrene-based resin 3: SB Ethylene-based resin: LLDPE Mixed resin: resin composition containing SB and LLDPE (containing LLDPE as the main component) <Antistatic layer> Antistatic agent 1: mixture of ionic liquid (1-ethyl-3-methylimidazolium ethyl sulfate), quaternary ammonium salt (ethyl dimethyl lauryl ammonium ethyl sulfate), and polyethylene glycol (antistatic agent concentration: 0.5% by mass). Antistatic agent 2: ATO Antistatic agent 3: aluminum oxide Antistatic agent 4: barium sulfate Antistatic agent 5: mixture of barium sulfate and tin oxide In addition, the notation "-" in Table 1 means that no anchor coat layer was provided.

[0204] [Examples I-1 to I-6 and Comparative Examples I-1 to I-3] For cover tapes I-1 to I-9, the transmittance and haze value were measured by the following methods. Furthermore, the moisture absorption rate was evaluated under high temperature and high humidity conditions under the following conditions. Furthermore, electronic component packages were prepared by the following method, and the visibility was evaluated. The results are shown in Table 2.

[0205] <Transmittance> The transmittance of cover tapes I-1 to I-9 at wavelengths of 1200 to 1600 nm was measured using the following method. The results are shown in Table 2 and Figure 1. The measurement and analysis equipment used was an ultraviolet-visible-near-infrared spectrophotometer (manufactured by Shimadzu Corporation, product name "UV-3600") and a multipurpose large sample chamber (φ60 mm, with a built-in integrating sphere; manufactured by Shimadzu Corporation, product name "MPC-3100"). First, baseline correction was performed without cover tape, and then the cover tape was attached and the spectral transmittance at wavelengths of 1200 to 1600 nm was measured using an integrating sphere.

[0206] <Haze Value> The haze values ​​of the cover tapes I-1 to I-9 were measured in accordance with JIS K7361-1:1997 using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "Haze Meter NDH 7000").

[0207] <Evaluation of Moisture Absorption Rate Under High Temperature and High Humidity> The moisture absorption rates of cover tapes I-1 to I-9 were measured using the following method. As a pretreatment, the cover tapes were stored under dry conditions of 60°C / 20% RH for 12 hours. Subsequently, after storing them under conditions of 60°C / 90% RH for 24 hours, the moisture absorption rates of the cover tapes were measured at a holding temperature of 280°C in accordance with JIS K0068:2001 "Karl Fischer titration method, moisture evaporation-coulometric titration method." Evaluation was also performed according to the following evaluation criteria, with a rating of B or higher being considered a pass. The results are shown in Table 2. (Evaluation criteria) Good: The moisture absorption rate under high temperature and high humidity was less than 3000 ppm by mass. Pass: The moisture absorption rate under high temperature and high humidity was 3000 ppm by mass or more and less than 5000 ppm by mass. Fail: The moisture absorption rate under high temperature and high humidity was 5000 ppm by mass or more.

[0208] <Visibility Evaluation> An electronic component (manufactured by Toshiba Corporation, product name "TCR2EN30") having a surface facing the cover tape of 0.8 mm x 0.8 mm square and 0.25 mm characters printed on the surface was stored in a carrier tape. Then, the cover tape was heat-sealed to the carrier tape under the conditions of sealing temperature: 150 ° C., sealing pressure: 0.5 kgf, sealing time: 0.3 seconds, and sealing time: 1 time to create an electronic component package. Then, the electronic components contained in the electronic component package from the cover tape side were photographed at a magnification of 150x using a digital microscope (Optoscience Corporation, product name "Dino-Lite Edge AM4815ZT"). Images taken from the cover tape side in which the orientation of the electronic components could be confirmed and the characters were clearly read were rated as passed, and images in which the orientation of the electronic components could not be confirmed or the characters were unclear and unreadable were rated as failed.

[0209]

[0210] As shown in Table 2 and FIG. 1, Examples I-1 to I-6 (cover tapes I-1 to I-6), which had a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%, exhibited low moisture absorption under high temperature and high humidity conditions and also had good visibility. Cover tape I-7 of Comparative Example I-1, which had a transmittance of 75% or more at wavelengths of 1300 to 1500 nm but a haze value of 30% or more, exhibited low moisture absorption under high temperature and high humidity conditions but had poor visibility. Furthermore, Comparative Examples I-2 to I-3 (cover tapes I-8 to I-9), which had a haze value of less than 30% but a transmittance of less than 75% at wavelengths of 1300 to 1500 nm, exhibited good visibility but very high moisture absorption rates under high temperature and high humidity conditions. From the above results, it was confirmed that the cover tape (I) according to the first embodiment is resistant to moisture absorption even under high temperature and high humidity conditions and also has good visibility.

[0211] [Second Embodiment: Cover Tape (II)] <Manufacture of Cover Tapes II-1 to II-6> The thermoplastic resins listed in Table 3 were selected as the thermoplastic resins constituting each layer. The thickness of each layer was determined as listed in Table 3. Then, following the steps (2) to (5) described above, the base layer, intermediate layer, heat seal layer, and antistatic layer were laminated in that order. Specifically, the heat seal layer resin composition was extruded using a single-screw extruder using the T-die method to form a heat seal layer. Next, the formed heat seal layer and the base layer (PET film) were extrusion-sand laminated with the molten intermediate layer resin composition to laminate the base layer, intermediate layer, and heat seal layer in that order. Furthermore, an antistatic layer was coated on the heat seal layer and dried to obtain cover tapes II-1 to II-6. For cover tapes II-3 to II-6, an anchor coat layer (urethane adhesive) was provided on the base layer, and then an intermediate layer was laminated on the surface of the anchor coat layer.

[0212] <Production of Cover Tapes II-7 to II-8> The thermoplastic resins listed in Table 3 were selected as the thermoplastic resins constituting each layer, and the thickness of each layer was determined as listed in Table 1. Then, the substrate layer, intermediate layer, heat seal layer, and antistatic layer were laminated according to the above-mentioned steps (2) to (5). Note that for cover tapes II-7 to II-8, anchor coat layers were provided between the substrate layer and the intermediate layer, and between the intermediate layer and the heat seal layer. The cover tapes were produced in the same manner as cover tapes II-1 to II-6.

[0213]

[0214] The components shown in Table 3 are the same as those shown in the cover tape (I). The symbol "-" in Table 3 indicates that no anchor coat layer was provided.

[0215] [Examples II-1 to II-5 and Comparative Examples II-1 to II-3] The transmittance and moisture absorption rate of each cover tape listed in Table 4 were measured by the following method. The results are shown in Table 4.

[0216] <Method for Measuring Transmittance> The transmittance of cover tapes II-1 to II-8 at wavelengths of 1200 to 1600 nm was measured in the same manner as for cover tape (I). The results are shown in Table 4 and FIG.

[0217] <Method for measuring moisture absorption rate under high temperature and low humidity> The moisture absorption rates of cover tapes II-1 to II-8 were measured using the following method. The results are shown in Table 4. After storing the cover tapes under dry conditions of 60°C / 20% RH for 12 hours, the moisture absorption rates of the cover tapes were measured at a holding temperature of 280°C using the Karl Fischer titration method in accordance with JIS K0068:2001 "Moisture evaporation - coulometric titration method." Evaluation was also conducted according to the following evaluation criteria, with a rating of B or higher being considered a pass. (Evaluation criteria) A: The moisture absorption rate under high temperature and low humidity was 1000 mass ppm or less. B: The moisture absorption rate under high temperature and low humidity was greater than 1000 mass ppm and less than 1500 mass ppm. C: The moisture absorption rate under high temperature and low humidity was greater than 1500 mass ppm.

[0218]

[0219] As shown in Table 4 and FIG. 2, Examples II-1 to II-5 (cover tapes II-1 to II-5), which had a transmittance of more than 80% at wavelengths of 1300 to 1500 nm, had little moisture absorption under high temperature and low humidity. On the other hand, Comparative Examples II-1 to II-3 (cover tapes II-6 to II-8), which had a transmittance of 80% or less at wavelengths of 1300 to 1500 nm, had a moisture absorption rate of more than 1500 mass ppm under high temperature and low humidity, and the amount of moisture absorbed by the cover tape was large. From the above results, it was confirmed that the cover tape (II) according to the second embodiment is less likely to absorb moisture even under high temperature and low humidity.

[0220] [Third Embodiment: Cover Tape (III)] <Manufacture of Cover Tapes III-1 to III-5> The thermoplastic resins listed in Table 5 were selected as the thermoplastic resins constituting each layer. The thickness of each layer was determined as listed in Table 5. Subsequently, the substrate layer, intermediate layer, heat seal layer, and antistatic layer were laminated in this order according to the aforementioned steps (2) to (5). Specifically, the heat seal layer resin composition was extruded using a single-screw extruder using the T-die method to form a heat seal layer. Next, the formed heat seal layer and the substrate layer (PET film) were extrusion-sand-laminated with the molten intermediate layer resin composition to laminate the substrate layer, intermediate layer, and heat seal layer in this order. Furthermore, an antistatic layer was coated on the heat seal layer and dried to obtain cover tapes III-1 to III-5. For cover tapes III-2 to III-5, an anchor coat layer (urethane adhesive) was provided on the substrate layer, and then an intermediate layer was laminated on the surface of the anchor coat layer.

[0221] <Production of Cover Tapes III-6 to III-7> The thermoplastic resins listed in Table 5 were selected as the thermoplastic resins constituting each layer, and the thickness of each layer was determined as listed in Table 5. Then, the substrate layer, intermediate layer, heat seal layer, and antistatic layer were laminated according to the above-mentioned steps (2) to (5). Note that for cover tapes III-6 to III-7, the cover tapes were produced in the same manner as cover tapes III-1 to III-5, except that an anchor coat layer was provided between the substrate layer and the intermediate layer, and between the intermediate layer and the heat seal layer.

[0222]

[0223] The components shown in Table 5 are the same as those shown in the cover tape (I). The symbol "-" in Table 5 indicates that no anchor coat layer was provided.

[0224] [Examples III-1 to III-4 and Comparative Examples III-1 to III-3] For each cover tape listed in Table 6, the moisture absorption rate (a), transmittance, and haze value were measured by the following methods. The results are shown in Table 6. The transmittance measurement results for each cover tape are also shown in Figure 3.

[0225] <Method for measuring moisture absorption rate (a)> The moisture absorption rates (a) of cover tapes III-1 to III-7 were measured in the same manner as for cover tape (II). The results are shown in Table 6.

[0226] <Method for Measuring Transmittance> The transmittance of cover tapes III-1 to III-7 at wavelengths of 1200 to 1600 nm was measured in the same manner as for cover tape (I).

[0227] Generally, near-infrared camera inspection requires high transmittance in the wavelength range of 1200 to 1600 nm. Therefore, the obtained transmittance was evaluated according to the following evaluation criteria. (Evaluation criteria for transmittance) Excellent: All transmittances in the wavelength range of 1200 to 1600 nm are 90% or more. Good: All transmittances in the wavelength range of 1200 to 1600 nm are 84% or more and less than 90%. Fair: All transmittances in the wavelength range of 1200 to 1600 nm are more than 80% and less than 84%. Poor: Any transmittance in the wavelength range of 1200 to 1600 nm is 80% or less.

[0228] <Method for measuring haze value> To improve visibility in camera inspection, a low haze value is also preferable. Therefore, the haze value of each cover tape was measured using the same method as for cover tape (I) and evaluated according to the following evaluation criteria. The results are shown in Table 6. (Evaluation criteria) Good: Haze value is 15% or more and less than 20%. Fair: Haze value is 20% or more and less than 25%. Unsatisfactory: Haze value is 25% or more.

[0229] <Overall Evaluation of Cover Tape (III)> Cover tapes that could not be evaluated for either transmittance or haze value were evaluated as "failed" (poor visibility in camera inspection). The results are shown in Table 6.

[0230]

[0231] As shown in Table 6 and FIG. 3, Examples III-1 to III-4 (cover tapes III-1 to III-4), which had a moisture absorption rate (a) of 1500 mass ppm or less, had high near-infrared transmittance. The cover tapes of Examples III-1 to III-4 were evaluated as excellent or good in transmittance, and also obtained good or fair haze values. Such cover tapes also tend to have good visibility in IR camera inspection. On the other hand, Comparative Examples III-1 to III-3 (cover tapes III-5 to III-7), which had a moisture absorption rate (a) of more than 1500 mass ppm, had low transmittance in the near-infrared wavelength range. In addition, cover tape III-5 of Comparative Example III-1 also had a high haze value. Therefore, the cover tapes of these comparative examples did not have sufficient visibility in IR camera inspection. From the above results, it was confirmed that the cover tape (III) according to the third embodiment has high transmittance in the near-infrared wavelength range.

[0232] The cover tapes (I) to (III) are suitable as cover tapes for electronic component packaging. The cover tape (I) according to the first embodiment has low moisture absorption under high temperature and high humidity conditions and good visibility. Therefore, it has industrial applicability, for example, as a low-moisture absorption cover tape (I) or a high-visibility cover tape (I) for electronic component packaging. The cover tape (II) according to the second embodiment has low moisture absorption under high temperature and low humidity conditions. Such a cover tape (II) also tends to have low moisture absorption due to humidity fluctuations, and therefore has industrial applicability, for example, as a low-moisture absorption cover tape (II) for electronic component packaging. The cover tape (III) according to the third embodiment has high transmittance in the near-infrared wavelength range and therefore has industrial applicability, for example, as a visibility-enhancing cover tape (III) for electronic component packaging.

Claims

1. A cover tape (I) having a transmittance of 75% or more at wavelengths of 1300 to 1500 nm and a haze value of less than 30%.

2. The cover tape (I) according to claim 1, which has a transmittance of 75% or more at wavelengths of 1200 to 1600 nm.

3. The cover tape (I) according to claim 1 or 2, wherein the rate of change in transmittance (T2) at a wavelength of 1600 nm relative to the transmittance (T1) at a wavelength of 1200 nm, as expressed by the following formula (1), is 90% or more: (T2 / T1) x 100(%) (1) 4. The cover tape (I) according to claim 1 or 2, which does not contain a polyamide resin.

5. A cover tape (I) according to claim 1 or 2, comprising at least a base layer, an intermediate layer, and a heat seal layer laminated in this order, the intermediate layer containing a polyolefin resin.

6. A cover tape (I) according to claim 1 or 2, comprising at least a base layer, an intermediate layer, and a heat seal layer laminated in this order, the intermediate layer not containing a polyamide resin.

7. The cover tape (I) according to claim 5, wherein the thickness of the heat seal layer is less than 20 μm.

8. The cover tape (I) according to claim 1 or 2, which is for use in packaging for electronic components.

9. An electronic component packaging body (I) comprising the cover tape (I) according to claim 1 or 2.

Images