JP7197052B2 - Electronic component packaging cover tape and package - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a cover tape for packaging electronic components and a package using the same.

In recent years, electronic parts such as ICs, resistors, transistors, diodes, capacitors, piezoelectric element resistors, etc. are tape-packaged and used for surface mounting. In taping packaging, after electronic components are housed in a carrier tape having a plurality of housings for housing electronic components, the carrier tape is heat-sealed with a cover tape to obtain a package for storing and transporting electronic components. When mounting electronic components, the cover tape is peeled off from the carrier tape, and the electronic components are automatically taken out and surface-mounted on the board. Note that the cover tape is also called a top tape.

In taping packaging, static electricity may be generated by peeling the cover tape from the carrier tape during mounting. This phenomenon is called peeling electrification, and due to peeling electrification, electronic components adhere to the cover tape during mounting, making it impossible to take out the electronic components normally, or causing the electronic components to pop out of the storage section of the carrier tape. be. This leads to a decrease in mounting efficiency. Furthermore, static electricity may cause deterioration and destruction of electronic components. Accordingly, various antistatic cover tapes have been proposed in order to suppress the generation of static electricity (see Patent Documents 1 and 2, for example).

Further, Patent Document 3 proposes a cover tape whose sealing strength is within a specific range when the cover tape is peeled off from the carrier tape.

WO2016/143600 Japanese Unexamined Patent Application Publication No. 2015-140200 JP 2005-096852 A

However, the present inventors found that the taped package obtained by heat-sealing the carrier tape with the conventional cover tape maintained good seal strength (peel strength) during storage and transportation under normal circumstances. Nevertheless, if stored in a moist and heat environment, the seal strength will decrease due to the load of moist heat, and the cover tape will be unintentionally peeled off before the cover tape is peeled off by the peeler when mounting the electronic components. It has been found that there is a problem that the electronic component, which is an object, falls off. In addition, the inventors have found that the antistatic property is lowered by a wet heat load, and as a result, defective mounting occurs during mounting.

The present disclosure has been made in view of the above problems. The purpose is to provide a cover tape.

An embodiment of the present disclosure includes a base layer, a heat seal layer disposed on one side of the base layer and sealed to a carrier tape having a plurality of storage portions for storing electronic components, and the base. and an antistatic layer disposed on the side opposite to the heat seal layer side surface of the material layer, and the electrification after a wet heat load stored for 100 hours in a wet heat environment of 40 ° C. and 95% RH The surface resistivity of the side on which the prevention layer is arranged is 1.0 × 10 ¹⁰ Ω / □ or less, and before the wet heat load, seal with a carrier tape having a plurality of storage portions for storing electronic components Provided is a cover tape for packaging electronic components, which has a strength of 0.7 N or less and a sealing strength with the carrier tape of 0.1 N or more after the wet heat load.

An embodiment of the present disclosure includes a carrier tape having a plurality of storage portions for storing electronic components, the electronic components stored in the storage portions, and the electronic component packaging described above arranged to cover the storage portions. and a cover tape for.

The electronic component packaging cover tape of the present disclosure suppresses unintended peeling of the cover tape even when stored and transported in a moist and hot environment, and is an electronic component packaging cover that can improve mounting efficiency during mounting. becomes a tape.

1 is a schematic cross-sectional view illustrating an electronic component packaging cover tape of the present disclosure; FIG. 1A and 1B are schematic plan and cross-sectional views illustrating a package of the present disclosure; FIG. 1 is a schematic cross-sectional view illustrating an electronic component packaging cover tape of the present disclosure; FIG.

Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be embodied in many different modes and should not be construed as limited to the description of the embodiments exemplified below. In addition, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the actual form, but this is only an example and limits the interpretation of the present disclosure. not something to do. In addition, in this specification and each figure, the same reference numerals may be given to the same elements as those described above with respect to the existing figures, and detailed description thereof may be omitted as appropriate.

In this specification, when expressing a mode of arranging another member on top of a certain member, when simply describing “above” or “below”, unless otherwise specified, 2 includes both cases in which another member is arranged directly above or directly below, and cases in which another member is arranged above or below a certain member via another member. In addition, in this specification, when expressing a mode in which another member is arranged on the surface of a certain member, when simply describing “on the surface side” or “on the surface”, unless otherwise specified, It includes both the case of arranging another member directly above or directly below so as to be in contact with it, and the case of arranging another member above or below a certain member via another member.

Electronic components are packaged as the above-described package at an electronic component manufacturing factory. Ideally, the package should be stored and transported in a well-controlled environment of normal temperature and normal humidity so as not to create a high-humidity environment. However, in reality, it is difficult to sufficiently control all environments such as warehouses, transportation facilities and containers, and factories that use electronic components. When transported, the package may be exposed to relatively high temperature and high humidity environments.

Carrier tapes are broadly classified into plastic carrier tapes made of plastic and paper carrier tapes made of paper. Paper carrier tapes generally absorb more moisture than plastic carrier tapes and are affected by high humidity environments. Cheap. The present inventors have found that when the cover tape is stored in a hot and humid environment, the antistatic property decreases.

In the past, major electronic components were large and heavy (1 mm or more for surface mounting, 1 cm or more for other connectors), so static electricity was difficult to adhere to. However, as electronic components became smaller in size (lighter), the problem of poor mounting due to static electricity became apparent. For this reason, mounting defects have occurred due to deterioration of the antistatic performance of the cover tape from the time the component manufacturer ships it to the time it is used by the mounting manufacturer due to warehousing and transportation in relatively hot and humid areas, which was not a problem in the past. A problem has arisen that has become apparent.

If an excessive amount of an antistatic agent is added to the heat seal layer in order to prevent mounting defects due to the deterioration of the antistatic performance, the seal strength will decrease even in the initial stage of production, and the cover tape will peel off. Such a problem occurs. In addition, low-molecular-weight antistatic agents tend to bleed out at temperatures higher than room temperature, which reduces the sealing strength of the cover tape.

Therefore, in order to maintain a predetermined seal strength even when stored in a hot and humid environment, it was conceived to strengthen the seal strength in advance. However, with the recent miniaturization of electronic components, if the seal strength is strengthened, the carrier tape will vibrate when peeling off the cover tape before wet heat deterioration, and the vibration will be transmitted to the electronic components, and when the measuring machine will pick up the electronic components. In addition, there are cases where the position of the electronic component sucked is displaced and the electronic component pops out of the housing. Therefore, it was difficult to increase the initial seal strength.

Therefore, the present inventors investigated the cause of the decrease in seal strength after a wet heat load, and found that the antistatic agent contained in the heat seal layer bleeds, induced by moisture absorbed by the carrier tape and moisture adhered to the surface. It was found out that it inhibits the sealing property. It was thought that the decrease in seal strength after wet heat load could be suppressed by reducing the amount of the antistatic agent contained in the heat seal layer, but at the same time there was concern about the decrease in the antistatic performance of the cover tape.

In particular, low-molecular-weight antistatic agents tend to migrate to high-polarity materials when the ambient temperature rises, so they migrate from the surface of the heat seal layer to a high-polarity layer such as a paper carrier tape, resulting in electrification. Preventive performance is reduced. Furthermore, in the case of using a highly hydrophilic antistatic agent from the viewpoint of cost advantage and performance, there is also a problem that the antistatic agent runs off due to moisture or condensation in a high humidity environment, resulting in deterioration of performance.

However, the present inventors have found that if the surface resistivity of the surface of the antistatic layer of the cover tape after wet heat load is a specific value or higher, it is possible to suppress peeling electrification when peeling the cover tape from the carrier tape. It has been found that the cover tape as a whole can exhibit sufficient antistatic properties. Therefore, the inventors have found that even if the amount of the antistatic agent in the heat seal layer is reduced, the decrease in seal strength after wet heat load can be suppressed without deteriorating the antistatic properties of the cover tape as a whole.
Hereinafter, the cover tape for electronic component packaging and the packaging body of the present disclosure will be described in detail.

A. Electronic component packaging cover tape The electronic component packaging cover tape of the present disclosure is sealed to a carrier tape having a base layer and a plurality of storage units arranged on one side of the base layer for storing electronic components. and an antistatic layer disposed on the side of the substrate layer opposite to the side of the heat-seal layer side of the base layer, and 100% in a moist heat environment of 40 ° C. and 95% RH. The surface resistivity of the side on which the antistatic layer is disposed is 1.0 × 10 ¹⁰ Ω/□ or less after a wet heat load after being stored for a long time, and the seal strength with the carrier tape before the wet heat load is 0 0.7 N or less, and the seal strength with the carrier tape after the wet heat load is 0.1 N or more. In this specification, the "cover tape for electronic component packaging" may be simply referred to as "cover tape".

It should be noted that "in a moist heat environment of 40° C. and 95% RH" is set assuming a high temperature and high humidity area, a storage environment in the area, and a transportation environment. In addition, the reason why "after storage for 100 hours" was set is for improving the efficiency of the evaluation because the evaluation after storage for 100 hours as an accelerated test shows a general tendency. In addition, it was set taking into account domestic transportation time and transportation container transshipment time.

The cover tape of the present disclosure has a surface resistivity of 1.0 × 10 ¹⁰ Ω/□ or less on the side on which the antistatic layer is arranged after a wet heat load, so that the entire cover tape is sufficiently charged. It has a preventive performance, and can suppress a decrease in mounting efficiency under a wet heat load. In addition, since the seal strength is 0.7 N or less before wet heat load, it is possible to suppress the electronic component from popping out of the storage pocket when peeling off the cover tape before wet heat deterioration occurs.

Furthermore, since the seal strength is 0.1 N or more after the wet heat load, a decrease in the seal strength after the wet heat load is suppressed. Therefore, even when a wet heat load is applied, it is possible to suppress unintended peeling of the cover tape and improve mounting efficiency during mounting.

A cover tape of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the cover tape of the present disclosure. As shown in FIG. 1, the cover tape 1 of the present disclosure includes a base layer 2, a heat seal layer 3 disposed on one side of the base layer 2, and a heat seal layer 3 side of the base layer 2. and an antistatic layer 4 disposed on the side opposite to the side of the .

2(a) and 2(b) are a schematic plan view and a cross-sectional view showing an example of a package using the electronic component packaging cover tape of the present disclosure, and FIG. 2(b) is A in FIG. -A line cross-sectional view. As shown in FIGS. 2A and 2B, the package 10 includes a carrier tape 11 having a plurality of storage units 12 for storing electronic components 13, electronic components 13 stored in the storage units 12, and storage and a cover tape 1 arranged to cover the portion 12 . The cover tape 1 is heat-sealed to the carrier tape 11, and heat-sealed portions 3h are provided in a line shape with a predetermined width at both ends of the heat-seal layer 3 of the cover tape 1. As shown in FIG. Moreover, in the package 10 , the carrier tape 11 can have feed holes 14 .

In the present disclosure, for example, on one side of the substrate, antistatic layer with high antistatic performance before wet heat deterioration and less deterioration of antistatic performance after wet heat deterioration (in particular, the first antistatic layer described later By providing the layer), it is possible to keep the surface resistivity of the surface on which the antistatic layer is arranged after the wet heat load within a predetermined range.

In addition, on the side opposite to the antistatic layer side of the base material, for example, by providing a heat seal layer that contains a small amount of antistatic agent or does not contain an antistatic agent, the carrier tape after wet heat load It is possible to make the sealing strength of the 1 within a predetermined range. As another method, the ratio of the thermoplastic resin in the heat seal layer is increased while considering the balance with other performance, so that the seal strength with the carrier tape after the wet heat load is within a predetermined range. becomes possible.

Each configuration of the cover tape of the present disclosure will be described below.
In the present disclosure, "wet heat load" means that the carrier tape and the cover tape are heat-sealed using a taping machine (NST-35 Nitto Kogyo) under the following conditions, and about 40 m is rolled onto a reel with a core diameter of 3 inches. The load applied when a reel sample wound into a shape is stored for 100 hours in a wet and heat environment of 40° C. and 95% RH in a laid down state. In addition, the surface resistivity and seal strength after a wet heat load, which will be described later, are obtained by storing the above reel sample in a wet heat environment of 40 ° C. and 95% RH for 100 hours, and then storing it in an environment of 25 ° C. and 40% RH for 24 hours or more. is a value measured against

(Taping condition)
・Paper carrier tape: Hokuetsu Corporation 0.31mm thick virgin paper 8mm wide ・Paper carrier tape sprocket hole pitch: 2mm
・Taping temperature 180℃
・Taping speed 3500 tact ・Taping iron size 0.6mm x 2 lines ・Taping iron length (seal length in 1 tact) 8±1mm

I. Antistatic Layer The antistatic layer in the present disclosure is a layer that is disposed on the side opposite to the heat seal layer side of the base layer and prevents the cover tape from being charged. By having the antistatic layer, it is possible to prevent the generation of static electricity due to contact with other surfaces, and to prevent the adhesion of dust and dirt to the surface of the cover tape due to static electricity.

The surface resistivity of the surface of the cover tape on which the antistatic layer is arranged after wet heat load in the present disclosure is 1.0×10 ¹⁰ Ω/□ or less, preferably 1.0×10 ⁹ Ω/□ or less. is.
Therefore, it is possible to suppress the increase in the peeling electrostatic voltage after the wet heat load. On the other hand, the lower limit of the surface resistivity of the surface of the cover tape on which the antistatic layer is arranged after the wet heat load is not particularly limited, but is, for example, 1.0×10 ⁵ Ω/□ or more, preferably 1.0. ×10 ⁷ Ω/□ or more. This is because if the surface resistivity is lowered too much, the cost becomes high.

In addition, the surface resistivity of the surface of the cover tape on which the antistatic layer is arranged before the wet heat load is usually 1.0×10 ¹⁰ Ω/□ or less, preferably 1.0×10 ⁹ Ω. /□ or less. On the other hand, the lower limit of the surface resistivity of the surface of the cover tape ^on which the antistatic layer is arranged before the wet heat load is not particularly limited. ×10 ⁷ Ω/□ or more.

In the present disclosure, "the side of the cover tape on which the antistatic layer is arranged" is not particularly limited, but is usually the surface of the antistatic layer. Further, the surface resistivity is a value obtained by using Mitsubishi Chemical Analyticc Hiresta UP MCP-HT450 under the following test conditions.

(Test condition)
・Probe: UA probe ・Applied voltage: Less than 10 ¹⁰ Ω/□ 10V
10 ¹⁰ to 10 ¹² Ω/□ 500V
10 ¹³ Ω/□ or more 1000V
・Sample size: 50cm x 40cm
・Measurement point: Central part of the sample ・Measurement value: Measure 5 points so that the measurement points do not overlap, and adopt the average value ・One measurement time: Adopt the display after 10 seconds ・Sample storage before measurement: 25 ℃ 40 Storage for 24 hours or more under %RH environment Measurement environment: 25±2°C, 40±5%RH environment

The antistatic layer in the present disclosure is not particularly limited, but includes a layer containing a conductive polymer, a layer containing a polymeric surfactant, and a layer containing a low-molecular-weight surfactant. Among them, the two embodiments of the first antistatic layer and the second antistatic layer described later are preferable because they can sufficiently suppress the increase in the surface resistivity after the wet heat load. In particular, the first antistatic layer, which will be described later, is preferable because it can sufficiently lower the surface resistivity after a wet heat load.

The thickness of the antistatic layer is a value necessary for the surface resistivity of the antistatic layer to satisfy the above value, and can be, for example, 0.02 μm or more and 3 μm or less. By forming the antistatic layer with such a thickness, antistatic properties can be imparted to the cover tape.

(1) First antistatic layer The first antistatic layer in the present disclosure contains a conductive polymer. The first antistatic layer contains a conductive polymer to reduce the surface resistance of the antistatic layer. In the second antistatic layer, which will be described later, the quaternary ammonium salt has a strong affinity for moisture in the air, attracts water molecules, and forms a moisture film on the surface of the antistatic layer, thereby lowering the surface resistance. In contrast, the conductive polymer in the first antistatic layer is itself conductive. Therefore, it is preferable because the surface resistivity can be sufficiently lowered.

(a) Conductive Polymer Examples of conductive polymers include polythiophene, polyaniline, polypyrrole, polyacetylene, polyparaphenylene, polyphenylene vinylene, and polyvinylcarbazole.
Among them, the conductive polymer is preferably polythiophene. As polythiophene, for example, PEDOT/PSS (poly(3,4-ethylenedioxythiophene/polystyrenesulfonic acid)) is preferably used.

(B) Crosslinked resin The first antistatic layer in the present disclosure has a crosslinked resin containing an acrylic main chain and a crosslinked structure in addition to the conductive polymer, and the crosslinked structure is -C (=O) OC It is preferred to have ₂ H ₄ NH- or -C(OH)CH ₂ OC(=O)-. By containing a crosslinked resin, the above-mentioned conductive polymer can be fixed, the outflow of the conductive polymer can be prevented under a moist heat load, and the surface of the cover tape on the side where the antistatic layer is arranged can suppress the increase in the surface resistivity of Such a first antistatic layer includes a conductive polymer, a first crosslinkable acrylic polymer having a carboxylate anion group, and a first polyfunctional curing agent, as described later. Formed from a protective material.

The crosslinked structure in the crosslinked resin contained in the first antistatic layer is the crosslinkable functional group (carboxylate anion (—COO—) and other crosslinkable functional groups) of the first crosslinkable acrylic polymer described later. , and the first polyfunctional curing agent, and have -C(=O)OC ₂ H ₄ NH- or -C(OH)CH ₂ OC(=O)-.

(c) First antistatic layer material The first antistatic layer material for forming the first antistatic layer comprises a conductive polymer and a first crosslinkable acrylic containing a carboxylate anion. It has a polymer and a first polyfunctional curing agent. Hereinafter, the polyfunctional curing agent contained in the first antistatic layer material is also referred to as the first polyfunctional curing agent.

(c1) Conductive Polymer Examples of the conductive polymer include those described in the above “I. Antistatic layer (1) First antistatic layer (a) Conductive polymer”.

(c2) First Crosslinkable Acrylic Polymer In the first crosslinkable acrylic polymer, the carboxylate anion group (-COO-) and optionally other groups act as crosslinkable functional groups. Furthermore, due to the presence of the carboxylate anion group (--COO--), it has a high affinity with the conductive polymer, and thus functions as a binder resin.

The first crosslinkable acrylic polymer is not particularly limited as long as it is an acrylic resin having a carboxylate anion group (--COO--) in its molecule, and known ones can be used.
For example, a copolymer obtained by reacting a monomer containing an acrylic monomer having a carboxyl group is neutralized (neutralized salt). As used herein, an acrylic monomer refers to a monomer having at least one (meth)acryloyl group in one molecule. Moreover, a (meth)acryloyl group is meant to comprehensively refer to an acryloyl group and a methacryloyl group.

A carboxylate anion group is derived from a carboxyl group possessed by an acrylic monomer. Acrylic acid and methacrylic acid are preferable as acrylic monomers having a carboxyl group.

In addition, as monomers other than acrylic monomers having a carboxyl group, various known (meth)acrylic acid alkyl esters, (meth)acrylamides, (meth)acrylic acid hydroxyalkyls, and other unsaturated monomers body can be used. Other unsaturated monomers may include a crosslinkable group such as a hydroxyl group capable of forming a crosslinked structure with the following polyfunctional curing agent.

Examples of neutralizing agents include ammonia, primary to tertiary amines, alkali metal compounds and alkaline earth metal compounds, and these can be used singly or in combination of two or more. .

(c3) First polyfunctional curing agent The first polyfunctional curing agent is not particularly limited as long as it has two or more functional groups capable of forming a crosslinked structure with the first crosslinkable acrylic polymer. However, aziridine-based curing agents and epoxy-based curing agents can be used.

The mixing ratio of the first crosslinkable acrylic polymer and the first polyfunctional curing agent in the first antistatic layer material is not particularly limited, but the molar ratio of the crosslinkable functional group in the crosslinkable acrylic polymer When the number (mol) is x and the number of moles (mol) of the functional group of the polyfunctional curing agent is y, x/y is usually about 0.5 to 2.0, preferably 0.75 to 1. 0.2.

Specifically, the content ratio of the conductive polymer, the first crosslinkable acrylic polymer, and the first polyfunctional curing agent in the first antistatic layer material is From the viewpoint of abrasion resistance, when the conductive polymer is 100 parts by mass, the crosslinkable acrylic polymer is 500 to 700 parts by mass, and the polyfunctional curing agent is 50 to 300 parts by mass, preferably 150 to 250 parts by weight.

(d) Forming method As a method for forming the antistatic layer, for example, the above conductive polymer, the first crosslinkable acrylic polymer, the first polyfunctional curing agent, etc. are dispersed or dissolved in a solvent to form an antistatic composition. A method of applying the above antistatic composition to the other side of the base material layer using a material and curing the composition is exemplified. Examples of the coating method of the antistatic composition include known coating methods such as air doctor, blade coating, knife coating, rod coating, bar coating, direct roll coating, reverse roll coating, gravure coating, and slide coating. .

(2) Second antistatic layer The second antistatic layer has an acrylic main chain, a side chain containing a quaternary ammonium salt, and a crosslinked resin containing a crosslinked structure, and the crosslinked structure is -NHC (=O ) O—, —NHC(=O)—, or —C(=O)OC ₂ H ₄ NH—. The second antistatic layer, as described later, comprises a second crosslinkable acrylic polymer containing a crosslinkable functional group and a group having a quaternary ammonium salt, and a second polyfunctional curing agent. Formed from a protective material.

(a) Crosslinked Resin The second antistatic layer in the present disclosure has a crosslinked resin that is a crosslinked resin, and the crosslinked resin includes an acrylic main chain, side chains containing a quaternary ammonium salt, and a crosslinked structure.
The quaternary ammonium salt has a function as a hydrophilic portion of the surfactant, and the quaternary ammonium salt oriented on the antistatic layer surface side has a strong affinity for water, attracts water molecules, and spreads to the antistatic layer surface. Surface resistance is lowered by forming a film of moisture. In addition, since the quaternary ammonium salt is fixed in the crosslinked resin, it is possible to prevent the outflow of the quaternary ammonium salt under wet heat load, and the antistatic layer of the cover tape after the wet heat load is disposed. An increase in the surface resistivity of the surface can be suppressed.

Examples of the quaternary ammonium salt in the crosslinked resin include those present as groups represented by the following formula (1).
−N ⁺ R ₃ (1)
(Where each R is independently the same or different organic group.)
R is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms from the viewpoint of the surface orientation of the quaternary ammonium salt. The quaternary ammonium salt represented by the above formula (1) is bound to the main acrylic chain via a divalent hydrocarbon group which may contain oxygen or nitrogen.

Examples of such a divalent hydrocarbon group include -X(CH ₂ ) _n - (wherein n is an integer of 1 to 6, X is an amide group (-C(=O)NH-) or an ester The group (--C(=O)O--), where the carbon atoms of the amide or ester group are attached to the main acrylic chain, are preferred.

The content of the quaternary ammonium salt contained in the antistatic layer is the value necessary for the surface resistivity of the surface of the cover tape on which the antistatic layer is arranged in the present disclosure to fall within the numerical range described above. can do.

The crosslinked structure is a structure in which the crosslinkable functional group of the second crosslinkable acrylic polymer described later and the second polyfunctional curing agent are bonded, and -NHC (= O) O -, -NHC (= O)- or -C(=O)OC ₂ H ₄ NH-. The second antistatic layer has an acrylic chain as its main chain. As used herein, the term acrylic chain is meant to comprehensively refer to acrylic chains and methacrylic chains.

(b) Second antistatic layer material The second antistatic layer material for forming the second antistatic layer is a second crosslinked material containing a group having a crosslinkable functional group and a quaternary ammonium salt. It has a polyfunctional acrylic polymer and a polyfunctional curing agent. A polyfunctional curing agent contained in the second antistatic layer material is referred to as a second polyfunctional curing agent.

(b1) Second crosslinkable acrylic polymer The second crosslinkable acrylic polymer contains a crosslinkable functional group and a group having a quaternary ammonium salt, and reacts with the polyfunctional curing agent to form a crosslinked structure. do. The crosslinkable functional group contained in the second crosslinkable acrylic polymer is not particularly limited as long as it can form a crosslinked structure with a polyfunctional curing agent, and examples thereof include a hydroxyl group and a carboxyl group. . Examples of the quaternary ammonium salt contained in the second crosslinkable acrylic polymer include those represented by the above formula (1).

In the present disclosure, the second crosslinkable acrylic polymer has a group having a crosslinkable functional group and a quaternary ammonium salt, and 50% by mass or more of the total amount of monomer components constituting the polymer is an acrylic monomer. is preferred.

The second crosslinkable acrylic polymer is an acrylic monomer (m1) having a group containing a quaternary ammonium salt (hereinafter referred to as component (m1)), an acrylic monomer having a crosslinkable functional group such as a hydroxyl group or a carboxyl group. Monomer (m2) (hereinafter referred to as component (m2)), and optionally other acrylic monomers or unsaturated monomers (m3) (hereinafter referred to as component (m3))) polymers.

Examples of component (m1) include acryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium bromide, acryloyloxyethylmethylammonium chloride, acryloyloxyethyldiethylmethylammonium chloride and acryloyloxyethyldimethylethylammonium chloride. These monomers can be used singly or in combination of two or more.

Specific examples of the (m2) component (meth)acrylic monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid and crotonic acid. These monomers can be used singly or in combination of two or more. Specific examples of the (meth)acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl ( Hydroxyalkyl (meth)acrylates such as meth)acrylates, and the like. These monomers can be used singly or in combination of two or more.

Examples of the (m3) component include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t -Butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate and other (meth)acrylic acid esters. These monomers can be used singly or in combination of two or more.

As the second crosslinkable acrylic polymer, a commercially available one can also be used. 1SX-1123 (manufactured by Taisei Fine Chemical Co., Ltd.) can be used.

(b2) Second polyfunctional curing agent The second polyfunctional curing agent has two or more functional groups capable of forming a crosslinked structure with the crosslinkable functional groups of the second crosslinkable acrylic polymer. There is no particular limitation, if any.
Specific examples of such polyfunctional curing agents include polyisocyanate curing agents, aziridine curing agents, and melamine curing agents.

The compounding ratio of the second crosslinkable acrylic polymer and the second polyfunctional curing agent in the second antistatic layer material is not particularly limited, but the molar ratio of the crosslinkable functional groups in the crosslinkable acrylic polymer When the number (mol) is x and the number of moles (mol) of the functional group of the polyfunctional curing agent is y, x/y is usually about 0.5 to 2.0, preferably 0.75 to 1. 0.2.

(c) Method of Formation As a method of forming the antistatic layer, for example, the antistatic layer material containing the second crosslinkable acrylic polymer, polyfunctional curing agent, moisture-absorbing and desorbing fine particles, etc. is dispersed or dissolved in a solvent. A method of applying an antistatic layer composition to the other side of the base material layer and curing the composition is exemplified. Examples of the coating method of the antistatic layer composition include known coating methods such as air doctor, blade coating, knife coating, rod coating, bar coating, direct roll coating, reverse roll coating, gravure coating and slide coating. be done.

(3) Third antistatic layer The antistatic layer in the present disclosure includes a third antistatic layer in addition to the first antistatic layer and the second antistatic layer. The third antistatic layer contains a highly hydrophobic low-molecular-weight surfactant and a crosslinked resin. Highly hydrophobic low-molecular-weight surfactants include polyoxyethylene alkylamines such as polyoxyethylene-laurylamine and polyoxyethylene-stearylamine. Examples of the crosslinked resin include those having an acrylic main chain and a crosslinked structure.

Materials constituting the third antistatic layer include a low-molecular-weight surfactant, a crosslinkable acrylic polymer, and a polyfunctional curing agent. From the viewpoint of antistatic performance, water resistance and abrasion resistance of the film, the solid content ratio is, for example, 0.3 to 0.7 parts by weight of the cross-linkable acrylic polymer when the low-molecular-weight surfactant is 1 part by weight. The polyfunctional curing agent is 0.1 to 0.3 parts by mass. Preferably, the crosslinkable acrylic polymer is 0.4-0.6 parts by mass, and the polyfunctional curing agent is 0.15-0.2 parts by mass.

II. Base Layer The base layer in the present disclosure is a layer that supports the antistatic layer and heat seal layer described above.
As a base material layer, mechanical strength to withstand external forces such as tensile force (force in the longitudinal direction of the reel) and tear strength due to taping machines during storage, transportation, chip filling, and mounting machines during chip mounting, manufacturing and taping Various materials can be applied as long as they have heat resistance to withstand packaging.

For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene terephthalate-isophthalate copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer, polyamides such as nylon 6, nylon 66, nylon 610, Polyolefins such as polyethylene, polypropylene, polymethylpentene, and the like are included. Among them, polyesters such as polyethylene terephthalate and polyethylene naphthalate are preferably used because of their cost and mechanical strength.

In addition, the substrate layer may contain additives such as fillers, plasticizers, colorants, and antistatic agents, if necessary. The substrate layer may be a single layer, or may be a laminate of multiple layers of the same or different types. Also, the substrate layer may be a stretched film or an unstretched film. Among others, the substrate layer may be a film uniaxially or biaxially stretched for the purpose of improving strength.

The thickness of the base material layer may be, for example, 2.5 μm or more and 300 μm or less, may be 6 μm or more and 100 μm or less, or may be 12 μm or more and 50 μm or less. If the thickness of the base material layer is too thick, the rigidity at the time of tape packaging is increased, which is disadvantageous in terms of handleability and cost. Moreover, when the thickness of the base material layer is too thin, the mechanical strength may be insufficient.

The substrate layer may be subjected to an adhesion-facilitating treatment such as corona discharge treatment, plasma treatment, ozone treatment, flame treatment, preheat treatment, dust removal treatment, vapor deposition treatment, alkali treatment, sandblast treatment, or the like.

III. Heat-sealing layer The heat-sealing layer in the present disclosure is a layer arranged on the opposite side of the base layer to the antistatic layer. When the cover tape of the present disclosure is used to manufacture a package, the heat seal layer is heat-sealed to the carrier tape to bond the cover tape and the carrier tape.

(1) Seal strength The cover tape in the present disclosure has a seal strength of 0.7 N or less, preferably 0.5 N or less, before wet heat load. This is because the carrier tape can be prevented from vibrating when the cover tape is peeled off during use before wet heat deterioration occurs, and there is no fear that the electronic component will jump out of the storage pocket. Moreover, the lower limit of the seal strength before the wet heat load is not particularly limited, and is, for example, 0.1 N or more, preferably 0.15 N or more. It is possible to prevent the cover tape from being peeled off from the carrier tape before the wet heat load and the dropout of the electronic component that is the content.

The cover tape in the present disclosure has a seal strength of 0.1 N or more, preferably 0.12 N or more, after a wet heat load. According to the present disclosure, the seal strength after a wet heat load can be made equal to or greater than the above value. Therefore, even after wet heat deterioration, it is possible to prevent the cover tape from being peeled off from the carrier tape before the cover tape is peeled off by the peeling device at the time of mounting the electronic component, and the electronic component that is the content can be prevented from falling off. .

Moreover, the upper limit of the seal strength after the wet heat load is not particularly limited, and is 0.5 N or less, preferably 0.4 N or less. This is because the carrier tape can be prevented from vibrating when the cover tape is peeled off even after a wet heat load, and there is no fear that the electronic component will jump out of the storage pocket.

In the present disclosure, the seal strength before wet heat load is measured by heat-sealing the carrier tape and cover tape using a taping machine (NST-35 Nitto Kogyo) under the above (taping conditions), and measuring about 40 m with a core diameter of 3 inches. A reel sample wound in a roll shape on a reel of 1 is stored in an environment of 25°C and 40% RH for 24 hours in a laid down state. The values are measured using the company EPI) under the following measurement conditions.

In addition, the seal strength after wet heat load was measured by storing the reel sample in an environment of 40° C. and 95% RH for 100 hours and then in an environment of 25° C. and 40% RH for 24 hours, and then peeling off the cover tape from the carrier tape. is the seal strength of

(Conditions for measuring seal strength)
・ Cover tape width 5.25±0.2mm
Measurement length 150mm
Peeling speed 300mm/min
Peeling angle 165-175°
Measurement environment 25±3℃, 40±10%RH
Measurement value Average value when measuring 150mm

(2) Surface resistivity In the present disclosure, the surface resistivity of the surface of the cover tape on which the heat seal layer is arranged is, for example, 1×10 ⁸ Ω/□ to 1×10 ¹⁵ Ω/□. Particularly preferably, it is 1×10 ⁸ Ω/□ to 1×10 ¹⁴ Ω/□.

Even if the heat seal layer has a relatively high surface resistivity, the cover tape according to the present disclosure has excellent antistatic performance of the antistatic layer, so that the cover tape as a whole has excellent antistatic performance. Moreover, if it is more than the said lower limit, the addition amount of an antistatic agent can be reduced and the fall of the seal strength by wet heat load can be suppressed. On the other hand, in order to obtain the necessary antistatic properties of the cover tape as a whole, it is preferably equal to or less than the above upper limit.
In addition, "the surface of the cover tape on which the heat-seal layer is arranged" is usually the surface of the heat-seal layer.

(3) Antistatic Agent The heat seal layer in the present disclosure preferably contains an antistatic agent. By adding an antistatic agent to the heat seal layer in addition to arranging the antistatic layer on the opposite side of the base layer to the heat seal layer, the antistatic property of the cover tape as a whole is further improved. be able to.

Examples of the antistatic agent contained in the heat seal layer include conductive polymers, polymeric surfactants, low-molecular-weight surfactants, and conductive fine particles. It is preferable because the agent is less likely to bleed out after a wet heat load and can suppress a decrease in seal strength after a wet heat load.

Examples of the conductive polymer include the same ones as those described above in "I. Antistatic layer (1) First antistatic layer (a) Conductive polymer", particularly PEDOT/PSS (poly(3 , 4-ethylenedioxythiophene/polystyrene sulfonic acid) is preferably used.

The content of the conductive polymer in the heat seal layer is such that the mixing ratio of the thermoplastic resin composition containing the thermoplastic resin (and, if necessary, additives) and the conductive polymer described later is the thermoplastic resin It is preferably 0.7 parts by mass or less, particularly preferably 0.55 parts by mass or less, relative to 100 parts by mass of the composition. By reducing the amount of the antistatic material, bleeding out of the antistatic agent contained in the heat seal layer can be suppressed, and reduction in seal strength after wet heat load can be suppressed.

Polymer type surfactants include cationic surfactants such as quaternary ammonium salts, pyridium salts, imidazolium salts, primary to tertiary amine salts, sulfonium salts, phosphonium salts; sulfonates, sulfuric acid Anionic surfactants such as ester salts and phosphate ester salts; amphoteric surfactants such as amino acid-based and amino acid sulfate ester-based; surfactants such as nonionic surfactants such as amino alcohol-based, glycerin-based, and polyethylene glycol-based Examples thereof include polymeric surfactants obtained by increasing the molecular weight of monomer components containing agents.

The content of the polymeric surfactant in the heat seal layer is determined by the mixing ratio of the thermoplastic resin composition containing the thermoplastic resin (and, if necessary, additives) to be described later and the polymeric surfactant. , 0.7 parts by mass or less, preferably 0.55 parts by mass or less per 100 parts by mass of the thermoplastic resin composition. This is because, by reducing the amount of the antistatic material, it is possible to suppress a decrease in seal strength after a wet heat load.

In addition, low-molecular-weight surfactants include cationic surfactants such as quaternary ammonium salts, pyridium salts, imidazolium salts, primary to tertiary amine salts, sulfonium salts, and phosphonium salts; , anionic surfactants such as sulfates and phosphates; amphoteric surfactants such as amino acids and amino acid sulfates; nonionic surfactants such as amino alcohols, glycerin and polyethylene glycol. mentioned.

The content of the low-molecular-weight surfactant in the heat seal layer is such that the mixing ratio of the thermoplastic resin composition containing the thermoplastic resin (and additives if necessary) and the low-molecular-weight surfactant described later is It is preferably 0.7 parts by mass or less, particularly preferably 0.55 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin composition. This is because, by reducing the amount of the antistatic material, it is possible to suppress a decrease in seal strength after a wet heat load.

Examples of conductive fine particles include metal fine particles such as gold, silver, nickel, aluminum, and copper, carbon black fine particles, conductive fine particles obtained by imparting conductivity to metal oxides such as tin oxide, zinc oxide, and titanium oxide, and barium sulfate. Conductive fine particles to which conductivity is imparted, conductive fine particles to which conductivity is imparted to sulfides such as zinc sulfide, copper sulfide, cadmium sulfide, nickel sulfide, and palladium sulfide.

(4) Thermoplastic resin The heat seal layer contains a thermoplastic resin, and the thermoplastic resin includes ethylene-vinyl acetate copolymer, acrylic resin, polyester resin, polyurethane resin, vinyl chloride-vinyl acetate. Any of copolymers or resins containing these as main components are preferred. Among them, it is preferable to contain an ethylene-vinyl acetate copolymer. By including the ethylene-vinyl acetate copolymer in the heat-sealing layer, the heat-sealing property to the carrier tape is improved. Therefore, it is possible to suppress the occurrence of unintended peeling during transportation, storage, or the like.

In the present disclosure, an ethylene-vinyl acetate copolymer is a copolymer containing at least ethylene monomer units and vinyl acetate monomer units. An ethylene monomer unit refers to a structural unit derived from an ethylene monomer, and a vinyl acetate monomer unit refers to a structural unit derived from a vinyl acetate monomer.

When the heat seal layer in the present disclosure contains an ethylene-vinyl acetate copolymer, it preferably further contains a polyethylene resin as a thermoplastic resin. By blending the polyethylene resin, it is possible to reduce the surface tackiness while maintaining good heat-sealing properties, and to suppress deterioration after being placed in a high-humidity and heat environment.

Polyethylene resins include various polyethylenes such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene. Low-density polyethylene (LDPE, Density 0.910 to less than 0.930) and linear low density polyethylene (LLDPE, density 0.910 to 0.925) are preferably used.

Further, in the present disclosure, classification of various polyethylenes refers to those defined in the old JIS K6748:1995 and JIS K6899-1:2000. The content of the polyethylene resin in the heat seal layer is preferably 10% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 40% by mass or less.

The heat seal layer may contain additives such as tackifiers, antiblocking agents, dispersants, fillers, plasticizers, and colorants, if necessary.

The thickness of the heat seal layer can be, for example, 0.5 μm or more and 30 μm or less, preferably 1 μm or more and 20 μm or less. If the thickness of the heat seal layer is too thin, the sealability may be poor, and a uniform film may not be obtained. If the thickness of the heat seal layer is too thick, the transparency of the cover tape may deteriorate.

As a method for forming the heat seal layer, for example, a heat seal layer composition in which a thermoplastic resin, an antistatic agent, other additives, etc. are dispersed or dissolved in a solvent is used, and the above A method of applying a composition for a heat seal layer and drying it may be mentioned. Examples of the method of applying the heat seal layer composition include roll coating, reverse roll coating, gravure coating, gravure reverse coating, comma coating, bar coating, wire bar coating, rod coating, kiss coating, knife coating, die coating, Known coating methods such as flow coating, dip coating, and spray coating can be used.

Also, a film can be used as the heat seal layer. In this case, the method for laminating the substrate layer and the heat seal layer is not particularly limited, and a known method can be used. Examples thereof include a method of bonding a pre-manufactured film to a substrate layer with an adhesive, and a method of extruding a heat-melted film raw material onto a substrate layer using a T-die or the like to obtain a laminate. As the adhesive in the former method, for example, a polyester-based adhesive, a polyurethane-based adhesive, an acrylic-based adhesive, or the like can be used.

In the present disclosure, the latter method (extrusion lamination method) is preferred. Specifically, the extrusion lamination method is, for example, a melt flow rate value measured according to JIS-K-7210 in which a thermoplastic resin, an antistatic agent and other additives are melt-kneaded (hereinafter, "MFR" may be described as) (190 ° C., 2.16 kg) is 10 g to 100 g pellets are used as the raw material for the heat seal layer, and the resin melted from the raw material is extruded on one side of the base layer, A method of lamination using a cooling roll can be mentioned.

In the present disclosure, an antistatic coating layer (second antistatic layer) containing an antistatic agent is provided on the side of the heat seal layer opposite to the base layer side, in addition to the antistatic layer described above. may The antistatic coat layer includes a layer containing the antistatic agent contained in the heat seal layer described above. In this case, the surface of the coat layer is the surface on which the heat seal layer of the cover tape is arranged.

IV. Cover Tape (1) Peeling Electrostatic Voltage The cover tape in the present disclosure preferably has an absolute peeling electrostatic voltage of 110 V or less, particularly 70 V or less when peeled from the carrier tape after a wet heat load. This is because the mounting success rate of electronic components is improved.
The peeling electrification voltage after the above wet heat load is obtained by heat sealing the carrier tape and the cover tape using a taping machine (NST-35 Nitto Kogyo) under the above (taping conditions), and about 40 m on a reel with a core diameter of 3 inches. A reel sample wound in a roll shape was stored in an inverted state at 40°C and 95% RH for 100 hours, and then stored at 25°C and 40% RH for 24 hours. Fuji Co., Ltd.) and a charge amount measuring device: SK-H050 (Keyence Co., Ltd.), and measured under the following test conditions.

(Test condition)
・Peeling speed: 100 mm/sec ・Measurement conditions: High accuracy mode, measurement time: 15 seconds ・Sample storage before measurement: Store at 25°C and 40% RH for 24 hours or longer ・Measurement environment: 25±2°C, 35±5% RH
Result calculation method: The peel electrification value is measured every 0.0014 seconds from 5 seconds to 13 seconds after the start of measurement, and the average value of the absolute values is calculated, and this is taken as the peel electrification voltage.

V. Other Configurations (1) Intermediate Layer In the present disclosure, an intermediate layer 5 may be arranged between the base material layer 2 and the heat seal layer 3, as shown in FIG. 3, for example. The intermediate layer can improve the adhesion between the substrate layer and the heat seal layer. In addition, the intermediate layer can improve the cushioning property when the cover tape of the present disclosure is heat-sealed to the carrier tape, so that heat can be applied more uniformly to the heat-seal layer.

The material of the intermediate layer is appropriately selected according to the materials of the base material layer and the heat seal layer, and examples thereof include polyolefins such as polyethylene and polypropylene, polyurethane, and polyester. The thickness of the intermediate layer can be, for example, 5 μm or more and 50 μm or less.

A film can be used as the intermediate layer. In this case, the method for laminating the substrate layer and the intermediate layer is not particularly limited, and known methods can be used. Examples thereof include a method of bonding a pre-manufactured film to a substrate layer with an adhesive, and a method of extruding a heat-melted film raw material onto a substrate layer using a T-die or the like to obtain a laminate. The adhesive is the same as that described in the section on the heat seal layer.

(2) Anchor Layer Further, an anchor layer may be provided between the substrate layer and the intermediate layer or between the intermediate layer and the heat seal layer. By forming the anchor layer, even if the substrate layer, the intermediate layer, or the heat-sealing layer has poor adhesive strength, the adhesive strength between the substrate layer and the intermediate layer, or between the intermediate layer and the heat-sealing layer Adhesion can be improved. The anchor layer may be appropriately selected depending on the materials used for the substrate layer, the intermediate layer, and the heat seal layer, and is not particularly limited. The anchor layer can be formed of, for example, a highly adhesive resin such as an olefin-based, acrylic, isocyanate-based, urethane-based, or ester-based adhesive.

B. Package The package of the present disclosure includes a carrier tape having a plurality of storage units for storing electronic components, the electronic components stored in the storage units, and the above-described cover tape arranged to cover the storage units. And prepare.

The cover tape in the present disclosure has high antistatic properties even under wet heat load. Therefore, by using the packaging body of the present disclosure, it is possible to suppress an increase in peeling electrification voltage due to a wet heat load, and improve mounting efficiency. Also, the cover tape in the present disclosure has good seal strength against the carrier tape even when subjected to wet heat load. Therefore, even after a wet heat load, it is possible to prevent the cover tape from peeling off from the carrier tape before the cover tape is peeled off by the peeling device when mounting the electronic component, and the electronic component that is the content can be prevented from falling off.

2(a) and 2(b) are a schematic plan view and a cross-sectional view showing an example of the package of the present disclosure. 2(a) and 2(b) have been described in the above section "A. Electronic component packaging cover tape", so description thereof will be omitted here.

Each configuration of the package of the present disclosure will be described below.
1. Cover tape The cover tape in the present disclosure has been described in the above section "A. Cover tape for electronic component packaging", so the description is omitted here.

In the package of the present disclosure, the heat seal layer of the cover tape and the carrier tape are adhered at the heat seal portion. The heat-sealed portion can be arranged, for example, in part of the portion where the heat-sealed layer of the cover tape contacts the carrier tape. That is, the heat-seal layer may have a heat-sealed portion and a non-heat-sealed portion. This makes it possible to improve the releasability of the cover tape from the carrier tape.

2. Carrier Tape A carrier tape in the present disclosure is a member having a plurality of storage units for storing electronic components.

Any carrier tape may be used as long as it has a plurality of storage units. Also called a tape.) can be used. Among them, an embossed carrier tape is preferably used from the viewpoint of cost, moldability, dimensional accuracy, and the like.

Examples of materials for the carrier tape include plastics such as polyvinyl chloride, polystyrene, polyester, polypropylene, polycarbonate, polyacrylonitrile, and ABS resin, and paper. In the present disclosure, paper refers to a material containing cellulose as a main component, and may further contain a resin component. A cover tape that is heat-sealed to a paper carrier tape tends to bleed out the antistatic agent contained in the heat-seal layer. Therefore, if the paper carrier tape is used, the effect of the cover tape of the present disclosure is exhibited more remarkably.

The thickness of the carrier tape is appropriately selected according to the material of the carrier tape, the thickness of the electronic component, and the like. For example, the thickness of the carrier tape can be 150 μm or more and 1500 μm or less. If the thickness of the carrier tape is too thick, the moldability will deteriorate, and if the thickness of the carrier tape is too thin, the strength may be insufficient.

A carrier tape has a some accommodating part. The storage units are usually arranged at predetermined intervals in the longitudinal direction of the carrier tape. The size, depth, pitch, etc. of the storage portions are appropriately adjusted according to the size, thickness, etc. of the electronic components.

As a method for forming the carrier tape having the storage portion, a general method for forming a carrier tape can be applied, and the method is appropriately selected according to the type and material of the carrier tape. Examples thereof include press molding, vacuum molding, air pressure molding, punching, and compression.

3. Electronic components The electronic components used in the package of the present disclosure are not particularly limited, and examples include ICs, resistors, capacitors, inductors, transistors, diodes, LEDs (light emitting diodes), liquid crystals, piezoelectric element resistors, filters, and crystal oscillators. child, crystal oscillator, connector, switch, volume, relay, and the like. The format of the IC is also not particularly limited.

4. Package The package of the present disclosure is used for storing and transporting electronic components. Electronic components are stored and transported in a package for mounting. At the time of mounting, the cover tape is peeled off, and the electronic component stored in the storage portion of the carrier tape is taken out and mounted on a board or the like.

Note that the present disclosure is not limited to the above embodiments. The above embodiment is an example, and any device that has substantially the same configuration as the technical idea described in the claims of the present disclosure and achieves the same effect is the present invention. It is included in the technical scope of the disclosure.

Examples and comparative examples are shown below to describe the present disclosure in more detail.
(Example 1)
As a substrate layer, a 25 μm-thick biaxially stretched polyethylene terephthalate film (FE2002 manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as a PET film) having both sides subjected to corona treatment was prepared. Antistatic coating agent (including PEDOT as a conductive polymer and aziridine as a curing agent, Aracoat AS601D/CL910 (mass ratio) = 10/1 manufactured by Arakawa Chemical Co., Ltd., concentration 3.0% on one side of the PET film Water/IPA = 3/7 solution) was applied at a wet weight (before drying) of 3.3 g/m ² and dried at 80°C for 1 minute to form an antistatic layer.

A urethane-based anchor coating agent (Takenate A-3075/Takelac A-3210 (mass ratio) = 3/1, diluted 5% with ethyl acetate) was applied to the side of the PET film opposite to the side on which the antistatic layer was formed. It was applied in a wet (before drying) film thickness of 1 μm and dried at 80° C. for 1 minute to form an anchor layer. Next, a polyethylene resin (Novatec LC600A, manufactured by Nippon Polyethylene Co., Ltd.) and ethylene-vinyl acetate copolymer composition 1 (the following formulation) were melt-extruded using cooling rolls having a surface roughness of Ra 0.5 μm and Rz 2.5 μm. They were laminated to a thickness of 15 μm to form an intermediate layer and a heat seal layer, respectively. Thus, a cover tape A1 having a structure of antistatic layer (1 μm or less)/base layer (25 μm)/anchor layer (1 μm or less)/intermediate layer (15 μm)/heat seal layer (15 μm) was produced.

Ethylene-vinyl acetate copolymer composition 1 contains ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Mitsui Dow Polychemicals) at 70.4% by mass, and low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.) at 20%. % by mass, modifier (Arcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 8% by mass, antistatic masterbatch (Rikemaster ELB-347, manufactured by Riken Vitamin Co., Ltd. (containing 25% antistatic agent)) 1.6 mass %including.

(Example 2)
Cover in the same manner as in Example 1 except that ethylene-vinyl acetate copolymer composition 2 was used instead of ethylene-vinyl acetate copolymer composition 1 and a cooling roll having a surface roughness Ra of 0.8 μm and Rz of 7.5 μm was used. A tape A2 was produced.

Ethylene-vinyl acetate copolymer composition 2 contains 69.6% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Dow Mitsui Polychemicals) and 20% low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). % by mass, modifier (Arcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 8% by mass, antistatic masterbatch (Rikemaster ELB-347, manufactured by Riken Vitamin Co., Ltd. (containing 25% antistatic agent)) 2.4 mass %including.

(Example 3)
Cover tape A3 was prepared in the same manner as in Example 1, except that ethylene-vinyl acetate copolymer composition 3 was used instead of ethylene-vinyl acetate copolymer composition 1.
Ethylene-vinyl acetate copolymer composition 3 contains 68% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Mitsui Dow Polychemicals) and 20% by mass of low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). , containing 12% by mass of a modifier (Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.).

(Comparative example 1)
A cover tape A4 was prepared in the same manner as in Example 1, except that the ethylene-vinyl acetate copolymer composition 4 was used instead of the ethylene-vinyl acetate copolymer composition 1.
Ethylene-vinyl acetate copolymer composition 4 contains 66.8% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Dow Mitsui Polychemicals) and 18% low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). % by mass, modifier (Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 12% by mass, antistatic masterbatch (Rikemaster ELB-347, manufactured by Riken Vitamin Co., Ltd. (containing 25% antistatic agent)) 3.2 mass %including.

(Comparative example 2)
Cover tape A5 was prepared in the same manner as in Example 1, except that ethylene-vinyl acetate copolymer composition 5 was used instead of ethylene-vinyl acetate copolymer composition 1.
Ethylene-vinyl acetate copolymer composition 5 contains 66% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Mitsui Dow Polychemicals) and 20% by mass of low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). , modifier (Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 10% by weight, and antistatic masterbatch (Rikemaster ELB-347, manufactured by Riken Vitamin Co., Ltd. (containing 25% antistatic agent)) 4% by weight.

(Comparative Example 3)
As a substrate layer, a 25 μm-thick biaxially stretched polyethylene terephthalate film (FE2002 manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as a PET film) having both sides subjected to corona treatment was prepared. Antistatic coating agent (including PEDOT as a conductive polymer and aziridine as a curing agent, Aracoat AS601D/CL910 (mass ratio) = 10/1 manufactured by Arakawa Chemical Co., Ltd., concentration 3.0% on one side of the PET film Water/IPA = 3/7 solution) was applied at a wet weight (before drying) of 3.3 g/m ² and dried at 80°C for 1 minute to form a first antistatic layer.

A urethane-based anchor coating agent (Takenate A-3075/Takelac A-3210 (mass ratio) = 3/1, 5% with ethyl acetate on the side opposite to the side on which the first antistatic layer of the PET film is formed. diluted) was applied in a wet (before drying) film thickness of 1 μm and dried at 80° C. for 1 minute to form an anchor layer. Next, a polyethylene resin (Novatec LC600A, manufactured by Nippon Polyethylene Co., Ltd.) and ethylene-vinyl acetate copolymer composition 6 (the following formulation) were melt-extruded using cooling rolls having a surface roughness of Ra 0.5 μm and Rz 2.5 μm. They were laminated to a thickness of 15 μm to form an intermediate layer and a heat seal layer, respectively.

After that, Aracoat AS601D/CL910 (mass ratio) = 10/1 (manufactured by Arakawa Chemical Co., Ltd., concentration 3.0% water/IPA = 3/7 solution) was applied at a wet (before drying) weight of 3.3 g/ ^m2 , and 80 C. for 1 minute to form a second antistatic layer on the heat seal layer.

Ethylene-vinyl acetate copolymer composition 6 contains 70% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Dow Mitsui Polychemicals) and 20% by mass of low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). , containing 10% by mass of a modifier (Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.).

(Comparative Example 4)
As a substrate layer, a 25 μm-thick biaxially stretched polyethylene terephthalate film (FE2002 manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as a PET film) having both sides subjected to corona treatment was prepared. Antistatic coating agent (including PEDOT as a conductive polymer and aziridine as a curing agent, Aracoat AS601D/CL910 (mass ratio) = 10/1 manufactured by Arakawa Chemical Co., Ltd., concentration 0.9% on one side of the PET film Water/IPA = 3/7 solution) was applied at a wet weight (before drying) of 3.3 g/m ² and dried at 80°C for 1 minute to form an antistatic layer.

A urethane-based anchor coating agent (Takenate A-3075/Takelac A-3210 (mass ratio) = 3/1, diluted 5% with ethyl acetate) was applied to the side of the PET film opposite to the side on which the antistatic layer was formed. It was applied in a wet film thickness of 1 μm and dried at 80° C. for 1 minute to form an anchor layer. Next, a polyethylene resin (Novatec LC600A, manufactured by Nippon Polyethylene Co., Ltd.) and ethylene-vinyl acetate copolymer composition 7 (the following composition) were melt-extruded using cooling rolls having a surface roughness of Ra 0.5 μm and Rz 2.5 μm. They were laminated to a thickness of 15 μm to form an intermediate layer and a heat seal layer, respectively.

Ethylene-vinyl acetate copolymer composition 7 contains 69.6% by mass of ethylene-vinyl acetate copolymer (Evaflex EV550, manufactured by Dow Mitsui Polychemicals) and 20% low-density polyethylene (Sumikasen L705, manufactured by Sumitomo Chemical Co., Ltd.). % by mass, modifier (Arcon P-125, manufactured by Arakawa Chemical Co., Ltd.) 8% by mass, antistatic masterbatch (Rikemaster ELB-347, manufactured by Riken Vitamin Co., Ltd. (containing 25% antistatic agent)) 2.4 mass %including.

(Comparative Example 5)
As a substrate layer, a 25 μm-thick biaxially stretched polyethylene terephthalate film (FE2002 manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as a PET film) having both sides subjected to corona treatment was prepared. An antistatic coating agent (Nymeen S-202, manufactured by NOF CORPORATION, concentration 2.0% IPA solution) was applied to one side of the PET film at a wet (before drying) weight of 3.3 g / m ² and heated at 80 ° C. for 1 minute. An antistatic layer was formed by drying. A urethane-based anchor coating agent (Takenate A-3075/Takelac A-3210 (mass ratio) = 3/1, diluted 5% with ethyl acetate) was applied to the side of the PET film opposite to the side on which the antistatic layer was formed. It was applied in a wet film thickness of 1 μm and dried at 80° C. for 1 minute to form an anchor layer.

Next, a polyethylene resin (Novatec LC600A, manufactured by Nippon Polyethylene Co., Ltd.) and ethylene-vinyl acetate copolymer composition 8 (the following formulation) were melt-extruded using cooling rolls having a surface roughness of Ra 0.5 μm and Rz 2.5 μm. They were laminated to a thickness of 15 μm to form an intermediate layer and a heat seal layer, respectively.

Ethylene-vinyl acetate copolymer composition 8 is an ethylene-vinyl acetate copolymer (Evaflex EV550, Dow Mitsui Polychemical Co., Ltd.) 73 mass%, low-density polyethylene (Sumikasen L705, Sumitomo Chemical Co., Ltd.) 18.2. 8% by mass of modifier (Alcon P-125, manufactured by Arakawa Chemical Co., Ltd.), and 0.8% by mass of antistatic agent (Plectron PVL).

[Measurement of surface resistivity (before wet heat load)]
The surface resistivity of the side on which the antistatic layer of the cover tape produced above is arranged (surface resistivity of the antistatic layer), and the surface resistivity of the side on which the heat seal layer is arranged ( The surface resistivity of the heat seal layer) was measured by the method described in the above "A. Electronic component packaging cover tape I. Antistatic layer". Table 1 shows the results.

[Production of package]
A package sample was produced using the above cover tape. While placing the electronic parts continuously in the storage part of the paper carrier tape, the paper carrier tape and the cover tape are sealed using a taping machine (NST-35 Nitto Kogyo) under the following conditions, and a core of about 40 m A roll-shaped package sample was obtained by winding on a reel with a diameter of 3 inches.

(Taping conditions)
・Paper carrier tape: 0.31mm thick 8mm wide virgin paper manufactured by Hokuetsu Corporation ・Paper carrier tape feed hole pitch: 2mm
・Taping temperature 180℃
・Taping speed 3500 tact ・Seal width 0.6×2mm
・Taping iron size 0.6mm x 2 lines ・Taping iron length (seal length in 1 tact) 8±1mm
・Electronic parts 0402 size capacitor

[Measurement of seal strength (before wet heat load)]
The roll-shaped package sample is left for 24 hours in a 25 ° C. 40% RH environment with the reel laid down, the taped package is removed from the reel, and the seal strength (before wet heat load) is measured according to the above "A. Electronic Cover tape for component packaging III. Table 1 shows the results.

[Wet heat load]
The roll-shaped package sample produced above was stored for 100 hours in an environment of 40° C. and 95% RH with the reel laid down. After that, it was left in an environment of 25° C. and 40% RH for 24 hours, and various evaluations described later were performed. Table 1 shows the results.

[Measurement of seal strength (after wet heat load)]
Take out the tape package from the reel of the roll-shaped package sample after wet heat load, and measure the seal strength (after wet heat load) with the above "A. Cover tape for electronic component packaging III. Heat seal layer (1) Seal strength" Measured by the method described. Table 1 shows the results.

[Measurement of surface resistivity (after wet heat load)]
Take out the taping package from the reel of the roll-shaped package sample after the wet heat load, peel off the cover tape from the carrier tape, and measure the surface resistivity of the side on which the antistatic layer of the cover tape is arranged (the antistatic layer Surface resistivity), and the surface resistivity of the side on which the heat seal layer is arranged (surface resistivity of the heat seal layer) are measured in the above "A. Electronic component packaging cover tape I. Antistatic layer" Measured by the method described. Table 1 shows the results.

[Measurement of peeling electrostatic voltage (after wet heat load)]
The taped package is taken out from the reel of the roll-shaped package sample after the wet heat load, and the peeling electrification voltage when peeling the cover tape from the carrier tape is measured according to the above "A. Cover tape for electronic component packaging IV. Cover tape (1 ) peeling electrification voltage”.
Table 1 shows the results.

[Chip mounting evaluation]
The cover tape is peeled off from the roll-shaped package after the wet heat load using a mounting machine (manufactured by NXT III FUJI, machine speed: standard, peeling method: immediately before adsorption), and the electronic component stored in the storage part implemented. 2000 chips were evaluated in an environment of 25±3° C. and 30±5% RH. Table 1 shows the results of the mounting success rate.

The cover tape of the present disclosure has good sealing strength against the carrier tape and high antistatic performance even when a wet heat load is applied (Examples 1 to 3). On the other hand, in the cover tapes of Comparative Examples 1 to 3, since the content of the antistatic agent in the heat seal layer or the second antistatic layer was large, the seal strength after wet heat load was lowered. This is presumed to be because the paper carrier tape absorbs moisture in the paste component when a wet heat load is applied, and the antistatic agent contained in the seal layer bleeds out, impairing the sealability.

In addition, the cover tape of Comparative Example 4 has a low antistatic agent content in the antistatic layer, and the cover tape of Comparative Example 5 does not have sufficient antistatic performance of the antistatic agent contained in the antistatic layer. In both cases, the surface resistivity after the wet heat load was high, and the peeling electrification voltage was high.

DESCRIPTION OF SYMBOLS 1... Cover tape 2... Base material layer 3... Heat seal layer 4... Antistatic layer 5... Intermediate layer 10... Package body 11... Carrier tape 12... Storage part 13... Electronic component

Claims (3)

a base layer;
a heat seal layer that is arranged on one side of the base material layer and that is sealed to a carrier tape having a plurality of storage portions for storing electronic components ;
an antistatic layer disposed on the side opposite to the side of the base material layer facing the heat seal layer;
has
The antistatic layer is a layer containing a conductive polymer,
The surface resistivity of the surface on which the antistatic layer is disposed is 1.0 × 10 ⁹ Ω/□ or less after a wet heat load stored in a wet heat environment of 40 ° C. and 95% RH for 100 hours,
The seal strength with the carrier tape before the wet heat load is 0.7 N or less,
A cover tape for packaging electronic components , which has a seal strength of 0.1 N or more with the carrier tape after being subjected to the wet heat load . 2. The method according to claim 1 , wherein the surface resistivity of the surface on which the heat seal layer is arranged after the wet heat load is 1.0×10 ⁸ Ω/□ or more and 1.0×10 ¹⁵ Ω/□ or less. electronic component packaging cover tape. a carrier tape having a plurality of storage units for storing electronic components;
an electronic component housed in the housing;
The electronic component packaging cover tape according to claim 1 or 2, arranged to cover the storage portion;
A package comprising:

Images