Cover tape manufacturing method

Abstract

To provide a cover tape for packaging electronic components, which has high transparency and excellent visibility of stored electronic components.SOLUTION: There is provided a cover tape for packaging electronic components, the cover tape including a base layer 1 and a sealant layer 2 provided on one side of the base layer 1, in which the number of bubbles with an area of more than 3000 μm2 and 10000 μm2 or less observed from a sealant layer side is 1000 or less per 1 cm2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cover tape and an electronic component package, and more particularly to a cover tape for packaging electronic components and an electronic component package including the cover tape. [Background technology]

[0002] 2. Description of the Related Art When transporting, storing, etc. electronic components, carrier tapes and cover tapes are often used. Specifically, electronic components (such as semiconductor chips) are placed in recesses formed in the carrier tape for storing electronic components, and then a cover tape is heat-sealed to the top surface of the carrier tape to enclose the electronic components. The carrier tape is then wound up into a reel for transportation / storage. This prevents contamination of the electronic components during transportation / storage.

[0003] Furthermore, the state of the packed electronic components needs to be confirmed through the cover tape. Therefore, the cover tape needs to have sufficient transparency to allow the stored electronic components to be inspected visually or by image processing. To solve the problem of transparency, Patent Document 1 combines a biaxially oriented film (Layer A) made of polyester, polypropylene, or nylon with a thermoplastic resin sealing layer (Layer B) on one side of Layer A, which is a mixture of 100 parts by weight of ethylene copolymer and 10 to 90 parts by weight of methacrylic acid ester copolymer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-284605 Summary of the Invention [Problem to be solved by the invention]

[0005] In the past, studies have focused on selecting the above-mentioned materials to improve the transparency of cover tapes, but the inventors of the present invention have found that there is still room for improvement in the transparency of cover tapes.

[0006] An object of the present invention is to provide a cover tape for packaging electronic components that is highly transparent and allows the stored electronic components to be easily seen. [Means for solving the problem]

[0007] According to the present invention, there are provided the following cover tapes and electronic component packages.

[0008] 1. A cover tape for packaging electronic components, The cover tape includes a base layer and a sealant layer provided on one side of the base layer, Area observed from the sealant layer side: 3000 μm 2 Ultra 10000μm 2 The number of bubbles below 1cm 2 Not more than 1000 pieces per cover tape. 2. The cover tape according to 1., 100 μm area observed from the sealant layer side 2 More than 3000μm 2 The number of bubbles below 1cm 2 No more than 500 pieces per cover tape. 3. The cover tape according to 1. or 2., The cover tape, wherein the base layer contains a polyester-based resin. 4. The cover tape according to any one of 1. to 3., The cover tape, wherein the sealant layer contains a styrene-based resin and / or a (meth)acrylic-based resin. 5. The cover tape according to any one of 1. to 4., At least one intermediate layer is provided between the base layer and the sealant layer, The intermediate layer has a density of 0.880 g / cm 3 More than 0.940g / cm 3 A cover tape comprising an ethylene-based resin, wherein: 6. The cover tape according to any one of 1. to 5., The cover tape is a laminated body. 7. A carrier tape having electronic components housed in recesses and the cover tape according to any one of 1. to 6. An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component. [Effects of the Invention]

[0009] According to the present invention, there is provided a cover tape for packaging electronic components that is highly transparent and allows excellent visibility of stored electronic components. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing the configuration of a cover tape according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an example of a state in which the cover tape for packaging electronic components of the present embodiment is sealed to a carrier tape. [Figure 3] (A) is a schematic diagram showing the method for observing bubbles, and (B) is an enlarged view of (A). DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail. In this specification, unless otherwise specified, the expression "a to b" in the description of a numerical range means from a to b. For example, "1 to 5 mass %" means "1 mass % to 5 mass %."

[0012] [Cover tape] The embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and their description will be omitted where appropriate. The drawings are schematic diagrams and do not correspond to the actual dimensional ratios.

[0013] <Overall properties of the cover tape> First, the overall properties of the cover tape of this embodiment will be described.

[0014] Fig. 1 is a schematic diagram showing an example of a cover tape for packaging electronic components according to the present embodiment. The cover tape 10 for packaging electronic components comprises a base layer 1 and a sealant layer 2 provided on one side of the base layer 1, and the sealant layer 2 is usually bonded to a carrier tape. In other words, the top side in Fig. 1 is usually bonded to a carrier tape.

[0015] 2, the method of using the cover tape 10 will be described. The cover tape 10 is used as a lid for a carrier tape 20 on which recessed pockets 21 are continuously formed to match the shapes of electronic components. Specifically, the cover tape 10 is used by adhering (e.g., heat sealing) to the surface of the carrier tape 20 so as to cover the entire openings of the pockets 21 of the carrier tape 20. In the following description, the structure obtained by adhering the cover tape 10 and the carrier tape 20 together will be referred to as an electronic component packaging body 100.

[0016] Each layer may be made up of multiple layers.

[0017] The cover tape is required to have high transparency to enhance the visibility of the electronic components contained therein. The present inventors have conducted research into ways to improve transparency from various perspectives and have found that the transparency of the cover tape can be improved by controlling the number of bubbles of a specific size.

[0018] The cover tape 10 for packaging electronic components of this embodiment comprises a base material layer 1 and a sealant layer 2 provided on one side of the base material layer 1, and has an area of ​​3000 μm as observed from the sealant layer 2 side.2 Ultra 10000μm 2 The number of bubbles below 1cm 2 It is characterized in that there are 1000 or less per unit area.

[0019] Area 3000μm 2 Ultra 10000μm 2 The number of bubbles below is evaluated by observing the cover tape from the sealant layer 2 side under magnification using a microscope or the like.

[0020] An example of the procedure for counting the number of bubbles will be described below. Fig. 3(A) is a schematic diagram showing a method for observing bubbles. Fig. 3(B) is an enlarged view of Fig. 3(A). Both Fig. 3(A) and (B) correspond to the cover tape of this embodiment observed from the sealant layer 2 side. (1) First, as shown in Figure 3(A) and Figure 3(B), a 1mm hole is placed on the center line L of the cover tape, 100 mm inward from the short side S of the cover tape. 2 Select the four bubble observation areas A1. (2) Next, as shown in Figure 3(B), a 1 mm bubble is placed on the center line L of the cover tape at a distance of 5 mm from the bubble observation area A1. 2 Select the bubble observation area A2 on all four sides. Similarly, select the bubble observation area A2 on the center line L of the cover tape, 1 mm apart from the bubble observation areas A2 to A9 at intervals of 5 mm. 2 Select each of the four bubble observation areas A3 to A10. (3) For each of the bubble observation areas A1 to A10, observe from the sealant layer 2 side of the cover tape using a microscope at a magnification of 200x, draw a rectangle that is in contact with the periphery of the observed bubble, and use the area of ​​the rectangle as the area of ​​the bubble. (4) For each of the bubble observation regions A1 to A10, the area calculated by the method is 3000 μm 2 Ultra 10000μm 2 Count the number of bubbles that are: (5) Area of ​​3000 μm observed in bubble observation areas A1 to A10 2 Ultra 10000μm 2 The total number of bubbles below is 10mm2 The number of bubbles per 10mm 2 Multiplying the number of bubbles per 10 gives a value of 100mm. 2 (1cm 2 ) is the number of bubbles per

[0021] Although the mechanism by which the transparency of the cover tape is improved by controlling the number of bubbles of a specific size is unclear, the inventors conducted various studies focusing on the size and number of bubbles and found that controlling the number of bubbles of a specific size suppresses the diffuse reflection of light incident on the cover tape. It is presumed that the transparency of the cover tape is improved by suppressing diffuse reflection in this way.

[0022] In order to improve the transparency of cover tapes, studies have traditionally focused on the selection of materials, with no attention paid to bubbles. In other words, the inventors have discovered an approach from a different perspective than conventional methods, namely, controlling the number of bubbles of a specific size.

[0023] Observed from the sealant layer 2 side, area 3000 μm 2 Ultra 10000μm 2 Air bubbles below 1cm 2 The number of particles per area is 1000 or less, preferably 500 or less, more preferably 200 or less, and even more preferably 150 or less. 2 Ultra 10000μm 2 Air bubbles below 1cm 2 When the number of pieces per unit area is equal to or less than the upper limit, the transparency of the cover tape is further improved, and the visibility of the stored electronic components is further improved.

[0024] From the viewpoint of facilitating production and preventing an increase in production costs, the area observed from the sealant layer 2 side is 3000 μm 2 Ultra 10000μm 2 Air bubbles below 1cm 2The number per unit is preferably 10 or more, more preferably 20 or more, and even more preferably 30 or more.

[0025] The total light transmittance of the cover tape can be used as an index of transparency of the cover tape. The total light transmittance of the cover tape of this embodiment is preferably 70% or more, and more preferably 80% or more. This ensures the transparency required to inspect whether electronic components are properly housed in an electronic component package consisting of the cover tape and carrier tape. In other words, by setting the total light transmittance of the cover tape to the above-mentioned lower limit or higher, it becomes easier to visually check the electronic components housed inside the package consisting of the cover tape and carrier tape from the outside.

[0026] The total light transmittance of the cover tape of this embodiment can be measured in accordance with JIS K 7361. The total light transmittance of each layer of the cover tape of this embodiment can also be measured in accordance with JIS K 7361.

[0027] In the above example, the area is 3000 μm 2 Ultra 10000μm 2 Air bubbles below 1cm 2 We have mentioned controlling the number of particles per 3000 μm in order to further improve the transparency of the cover tape. 2 Ultra 10000μm 2 Not only bubbles below this size, but also smaller bubbles, specifically those with an area of ​​100 μm 2 More than 3000μm 2 It is also preferable to control the number of bubbles described below.

[0028] In addition, the area is 100 μm 2 More than 3000μm 2 Air bubbles below 1cm 2 The number of particles per area is 3000 μm. 2 Ultra 10000μm 2 Air bubbles below 1cm 2 They can be counted in the same way as the number of winning pieces.

[0029] Observed from the sealant layer 2 side, area 100 μm 2 More than 3000μm 2 Air bubbles below 1cm 2 The number per unit area is preferably 500 or less, more preferably 400 or less, and even more preferably 200 or less. Area is 100 μm 2 More than 3000μm 2 Air bubbles below 1cm 2 When the number of pieces per unit area is equal to or less than the upper limit, the transparency of the cover tape is further improved, and the visibility of the stored electronic components is further improved.

[0030] From the viewpoint of facilitating production and preventing an increase in production costs, a film having an area of ​​100 μm 2 observed from the sealant layer 2 side is used. 2 More than 3000μm 2 Air bubbles below 1cm 2 The number per unit is preferably 10 or more, more preferably 20 or more, and even more preferably 30 or more.

[0031] The overall thickness of the cover tape of this embodiment is preferably 30 μm or more, more preferably 35 μm or more, in order to ensure strength, and is preferably 70 μm or less, more preferably 60 μm or less, in order to ensure flexibility.

[0032] The width and length of the cover tape of this embodiment can be appropriately set mainly depending on the width and length of the carrier tape. Typically, the width of the cover tape is about 1 to 100 mm, and the length is about 100 to 30,000 m.

[0033] <Characteristics of the manufacturing method> There are no limitations on the method for manufacturing the cover tape 10 of this embodiment. For example, the cover tape 10 can be manufactured by applying a known method such as an extrusion method, a lamination method, or a coating method.

[0034] Specifically, the cover tape 10 of this embodiment can be manufactured by the following steps (1) to (4). (1) A film (PET film, etc.) corresponding to the base layer 1 is prepared. (2) A film corresponding to the intermediate layer is prepared. When the intermediate layer has multiple layers, it is formed by, for example, a multi-layer extruder. (3) An adhesive material is applied to one side of the prepared film corresponding to the base layer 1, and a film corresponding to the intermediate layer is attached to it. In other words, a laminate of the base layer 1 and the intermediate layer is formed by dry lamination. The applied adhesive material becomes the adhesive layer. (4) Laminate of base layer 1 and intermediate layer: A coating liquid for forming sealant layer 2 is applied to the exposed surface of the intermediate layer of the laminate using a bar coater or the like. Then, the solvent in the applied coating liquid is dried. In this manner, the sealant layer 2 can be provided. The coating liquid for forming sealant layer 2 can be one in which the above-mentioned styrene-based resin and / or (meth)acrylic resin is dissolved or dispersed in some kind of solvent. The concentration of non-volatile components, viscosity, and surface tension of the coating liquid can be adjusted as appropriate.

[0035] In the above step (2), when manufacturing a film corresponding to the intermediate layer or laminating a film corresponding to the intermediate layer, the maximum height Rz of the surface of the intermediate layer on the substrate layer side can be adjusted by adjusting the surface roughness of the roll that comes into contact with the surface of the intermediate layer within an appropriate range, and in this way, it is possible to adjust the number of bubbles observed from the sealant layer 2 side.

[0036] Specifically, the maximum height Rz of the surface of the intermediate layer on the side of the base layer 1 is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less. By having the maximum height Rz be equal to or less than the above upper limit, the area of ​​3000 μm observed from the sealant layer 2 side can be reduced. 2 Ultra 10000μm 2 The number of bubbles below and the area of ​​100 μm observed from the sealant layer 2 side 2 Ultra 3000μm 2 The number of bubbles can be further reduced as follows.

[0037] Rz is evaluated in accordance with JIS B 0601-2001. According to JIS B 0601-2001, a portion of the roughness curve measured with a roughness meter is extracted over a reference length, and Rz is calculated as the sum of the highest point (maximum peak height: Rp) and the deepest point (maximum valley depth: Rv). In other words, it evaluates the roughness of the material surface in the height direction.

[0038] In the above step (4), the number of bubbles observed from the sealant layer 2 side can be adjusted by adjusting the viscosity and surface tension of the coating liquid for forming the sealant layer 2 within an appropriate range.

[0039] For example, the viscosity of the coating liquid for forming the sealant layer 2 is preferably 20 to 90 mPa·s, and more preferably 30 to 80 mPa·s. When the viscosity is within the above range, the area of ​​3000 μm observed from the sealant layer 2 side is 2 Ultra 10000μm 2 The number of bubbles below and the area of ​​100 μm observed from the sealant layer 2 side 2 Ultra 3000μm 2 The number of bubbles can be further reduced as follows.

[0040] <Properties of each layer that makes up the cover tape> The properties of each layer constituting the cover tape of this embodiment will be described below.

[0041] (base material layer) The base material layer 1 can be a film made from various materials, as long as it has the mechanical strength to withstand the external forces applied when processing the cover tape 10 for packaging electronic components, when heat-sealing it to the carrier tape 20, and during use, and the heat resistance to withstand the heat generated during heat-sealing.

[0042] The thickness of the base material layer 1 is, for example, 5 μm or more, preferably 6 μm or more, and more preferably 7 μm or more. When the thickness of the base material layer 1 is equal to or greater than the above lower limit, the mechanical strength of the cover tape 10 is sufficiently ensured.

[0043] The thickness of the base layer 1 is, for example, 35 μm or less, preferably 30 μm or less. When the thickness of the base layer 1 is equal to or less than the above upper limit, the rigidity of the cover tape 10 does not become too high, and when a torsional stress is applied to the carrier tape 20 after sealing, the cover tape 10 is prevented from peeling off due to deformation of the carrier tape 20.

[0044] The base layer 1 may be a single layer or may be composed of multiple layers. When the base layer 1 is composed of multiple layers, the total thickness of the layers is the "thickness of the base layer 1."

[0045] The total light transmittance of the base layer 1 is preferably 80% or more, and more preferably 85% or more. When the total light transmittance is equal to or less than the above upper limit, the transparency of the cover tape in an electronic component package consisting of the cover tape 10 and the carrier tape is further improved, and it is possible to more accurately inspect whether the electronic components housed inside the package consisting of the cover tape and the carrier tape are housed correctly.

[0046] Specific examples of materials constituting the base layer 1 include one or more selected from polyester-based resins, polyamide-based resins, polyolefin-based resins, polyacrylate-based resins, polymethacrylate-based resins, polyimide-based resins, polycarbonate-based resins, and ABS resins.

[0047] From the viewpoint of improving mechanical strength, it is preferable that the base layer 1 contains a polyester-based resin. As the polyester-based resin, for example, polyethylene terephthalate can be used.

[0048] In addition to the above components, the base layer 1 may contain any additives such as an antiblocking agent, a slip agent, a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, a colorant, a surfactant, and an inorganic filler, as long as the properties of the base layer are not impaired.

[0049] (sealant layer) The sealant layer 2 is not particularly limited as long as it is capable of heat-sealing the cover tape 10 to the carrier tape (it melts appropriately when heated).

[0050] The thickness of the sealant layer 2 is, for example, 0.01 μm or more, preferably 0.05 μm or more, and more preferably 0.07 μm or more. When the thickness of the sealant layer 2 is equal to or greater than the above-mentioned lower limit, sufficient peel strength can be ensured. Furthermore, the occurrence of cracks due to twisting can also be suppressed.

[0051] The thickness of the sealant layer 2 is, for example, 4 μm or less, preferably 3 μm or less, and more preferably 2.5 μm or less. When the thickness of the sealant layer 2 is equal to or less than the above upper limit, the rigidity of the cover tape does not become too high, and therefore, even when a torsional stress is applied to the carrier tape after sealing, the cover tape can easily follow the deformation of the carrier tape, and unintentional peeling of the cover tape from the carrier tape can be suppressed.

[0052] The sealant layer 2 may be a single layer or may be composed of multiple layers. When the sealant layer 2 is composed of multiple layers, the total thickness of the individual layers is the "thickness of the sealant layer 2."

[0053] The total light transmittance of the sealant layer 2 is preferably 80% or more, and more preferably 85% or more. When the total light transmittance is equal to or less than the above upper limit, the transparency of the cover tape in an electronic component package consisting of the cover tape 10 and the carrier tape is further improved, and it is possible to more accurately inspect whether the electronic components housed inside the package consisting of the cover tape and the carrier tape are properly housed.

[0054] From the viewpoint of compatibility with other layers, the sealant layer 2 preferably contains a styrene-based resin and / or a (meth)acrylic-based resin.

[0055] These resins will be described below.

[0056] (styrene resin) The styrene-based resin refers to a polymer containing structural units derived from styrene.

[0057] From the viewpoint of the balance between peel strength and conformability to deformation, the styrene content in the styrene-based resin is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more.

[0058] From the viewpoint of the balance between peel strength and conformability to deformation, the styrene content in the styrene-based resin is preferably 90% by mass or less, more preferably 80% by mass or less, and even more preferably 70% by mass or less.

[0059] The styrene content refers to the proportion (mass%) of styrene-derived structural units contained in a styrene-based resin. When a styrene-based resin contains two or more copolymers, the average of the styrene contents of the individual copolymers is the styrene content of the styrene-based resin.

[0060] Examples of styrene-based resins include styrene-based polymers such as polystyrene, styrene-(meth)acrylate copolymers, styrene-olefin copolymers, hydrogenated styrene block copolymers, high impact polystyrene (HIPS), and general-purpose polystyrene resins (GPPS; General Purpose Polystyrene); and styrene-based oligomers such as styrene-based polymers, α-methylstyrene-based polymers, styrene-(α-methylstyrene)-based copolymers, styrene-aliphatic hydrocarbon-based copolymers, styrene-(α-methylstyrene)-aliphatic hydrocarbon-based copolymers, and styrene-aromatic hydrocarbon-based copolymers. The styrene resin may be used alone or in combination of two or more.

[0061] From the viewpoint of further improving the peel strength, it is preferable to use a styrene-(meth)acrylate copolymer and / or a styrene-olefin copolymer as the styrene-based resin constituting the sealant layer 2.

[0062] From the viewpoint of the balance between peel strength and adaptability to deformation, the content of the styrene resin in the nonvolatile components of the resin composition for forming the sealant layer 2 is preferably 5% by mass or more, more preferably 8% by mass or more.

[0063] The content of the styrene-based resin may be 100% by mass of the non-volatile components of the resin composition for forming the sealant layer 2, but from the viewpoint of the balance between peel strength and conformability to deformation, it is preferably 90% by mass or less, and more preferably 80% by mass or less.

[0064] ((Meth)acrylic resin) The (meth)acrylic resin refers to a polymer containing structural units derived from a (meth)acrylic acid ester.

[0065] Examples of the (meth)acrylic acid ester include one or more selected from methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, hexyl (meth)acrylate, and ethylhexyl (meth)acrylate.

[0066] The (meth)acrylic resin may be a copolymer with other monomers as long as they do not fall under the above-mentioned components. For example, the (meth)acrylic resin may be a copolymer containing one or more selected from the group consisting of an ethylene-methyl (meth)acrylate copolymer, an ethylene-ethyl (meth)acrylate copolymer, an ethylene-(meth)acrylate copolymer, and an ethylene-vinyl acetate copolymer. The (meth)acrylic resin contains structural units derived from a (meth)acrylic acid ester in an amount of, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more.

[0067] From the viewpoint of the balance between peel strength and deformation compliance, the content of the (meth)acrylic resin in the non-volatile components of the resin composition for forming the sealant layer 2 is preferably 1 mass % or more, more preferably 10 mass % or more, and even more preferably 20 mass % or more.

[0068] The content of the (meth)acrylic resin in the non-volatile components of the resin composition for forming the sealant layer 2 may be 100% by mass, but from the viewpoint of the balance between peel strength and adaptability to deformation, it is preferably 98% by mass or less.

[0069] When a styrene-based resin and a (meth)acrylic resin are used in combination, the mass ratio [(styrene-based resin content) / ((meth)acrylic resin content)] is preferably 0.015 or more, and more preferably 0.020 or more. Furthermore, the mass ratio of [(styrene resin content) / ((meth)acrylic resin content)] is preferably 5 or less, and more preferably 4 or less. By setting the lower and upper limits of the mass ratio within the above ranges, the balance between releasability and adhesion can be further improved.

[0070] (antistatic agent) The sealant layer 2 may contain an antistatic agent to prevent the electronic components packaged in the cover tape from adhering to the cover tape.

[0071] Examples of the antistatic agent include inorganic antistatic agents such as tin oxide, zinc oxide, and titanium oxide; surfactants such as polyoxyethylene alkylamine, quaternary ammonium, and alkylsulfonate; conductive polymers such as polythiophene, polyaniline, or polypyrrole, or derivatives thereof, and carbon nanotubes. When an antistatic agent is used, one type may be used alone, or two or more types may be used in combination.

[0072] From the viewpoint of having good compatibility in the resin, the antistatic agent preferably contains a conductive polymer, and more preferably contains polythiophene or a polythiophene derivative.

[0073] From the viewpoint of the balance between antistatic performance and peel strength, the content of the antistatic agent is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 80% by mass or less, based on the entire sealant layer 2.

[0074] (Other added ingredients) In addition to the above components, the sealant layer 2 may contain any additives such as an antistatic agent, a tackifier, an antiblocking agent, a slip agent, a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, a colorant, a surfactant, and an inorganic filler, as long as the properties of the sealant layer 2 are not impaired, and the surface of the sealant layer 2 may be coated with these additives.

[0075] The content of other additive components in the sealant layer 2 may be adjusted appropriately depending on the purpose of addition. Typically, the content of each additive component may be adjusted to within a range of about 0.01 to 10% by mass based on the entire sealant layer 2.

[0076] (middle class) In the cover tape 10 of this embodiment, an intermediate layer (not shown) may be provided between the base material layer 1 and the sealant layer 2.

[0077] By providing the intermediate layer, the flexibility of the entire cover tape can be adjusted to improve cushioning properties, and the adhesion to the carrier tape, which is the object to be adhered, can also be improved.

[0078] The thickness of the intermediate layer 2 is, for example, 20 μm or more, preferably 23 μm or more. When the thickness of the intermediate layer 2 is equal to or greater than the above-mentioned lower limit, the cushioning properties of the cover tape 10 can be further improved. Also, the adhesion between the cover tape 10 and the carrier tape 20 during sealing can be improved.

[0079] The thickness of the intermediate layer 2 is, for example, 45 μm or less, preferably 40 μm or less. When the thickness of the intermediate layer 2 is equal to or less than the above upper limit, the rigidity of the cover tape does not become too high, and therefore, even when a torsional stress is applied to the carrier tape after sealing, the cover tape can easily follow the deformation of the carrier tape, and unintentional peeling of the cover tape from the carrier tape can be suppressed.

[0080] The intermediate layer may be a single layer or may be composed of multiple layers. When the intermediate layer is composed of multiple layers, the total thickness of the layers is the "thickness of the intermediate layer."

[0081] The resin contained in the intermediate layer is not particularly limited. For example, one or more resins selected from styrene-based resins, (meth)acrylic resins, olefin-based resins, and copolymers thereof can be used. Among these, olefin-based resins are preferred, polyethylene or ethylene copolymers are more preferred, and low-density polyethylene (LDPE) or linear low-density polyethylene (L-LDPE) are even more preferred. When the resin contained in the intermediate layer is a copolymer, the copolymerization may be in any of a random, alternating, block or other manner.

[0082] The density of the resin contained in the intermediate layer is preferably 0.880 g / cm 3 More than 0.940g / cm 3 or less, more preferably 0.885 g / cm 3 More than 0.935g / cm 3 or less, and more preferably 0.890 g / cm 3 More than 0.930g / cm 3 The density of the resin contained in the intermediate layer is within the above range, so that the cushioning properties and rigidity of the cover tape 10 can be balanced to an even higher degree.

[0083] Examples of resins having a density within the above range include polyethylene and ethylene copolymers.

[0084] The content of the resin having a density within the above range is preferably 90 to 100% by mass, and more preferably 95 to 100% by mass, based on the total solid content of the resin composition constituting the intermediate layer.

[0085] The density of the intermediate layer is preferably 0.880 g / cm 3 More than 0.940g / cm 3 or less, more preferably 0.885 g / cm 3 More than 0.935g / cm 3 or less, and more preferably 0.890 g / cm 3 More than 0.930g / cm 3 The density of the intermediate layer is within the above range, so that the cushioning properties and rigidity of the cover tape 10 can be balanced to an even higher degree.

[0086] The total light transmittance of the intermediate layer is preferably 80% or more, and more preferably 85% or more. This ensures the transparency required to inspect whether the electronic components are properly housed in the electronic component package consisting of the cover tape and carrier tape. In other words, by making the total light transmittance of the intermediate layer 80% or more, the electronic components housed inside the package consisting of the cover tape and carrier tape can be easily visually confirmed from the outside.

[0087] In addition to the above components, the intermediate layer may contain any additives such as an antiblocking agent, a slip agent, a lubricant, a plasticizer, an antioxidant, an ultraviolet absorber, a colorant, a surfactant, and an inorganic filler, as long as the properties of the intermediate layer are not impaired.

[0088] (Other layers) The cover tape 10 of this embodiment may have other layers in addition to the base material layer 1, the sealant layer 2, and the intermediate layer.

[0089] For example, an adhesive layer (not shown) may be provided. This adhesive layer can improve the adhesion between the layers. Examples of materials for forming the adhesive layer include urethane-based adhesive resins for dry lamination or adhesive resins for anchor coating, and generally include a combination of a polyester composition such as polyester polyol or polyether polyol with an isocyanate compound.

[0090] In addition to the adhesive layer, for example, a reinforcing layer for improving the strength of the entire film, a water vapor barrier layer for blocking water vapor, etc. may be provided.

[0091] [Electronic component packaging] As shown in FIG. 2, the electronic component packaging body 100 of this embodiment comprises a carrier tape in which electronic components are housed in recesses, and the above-mentioned cover tape, with a sealant layer 2 adhered to the carrier tape so as to seal the electronic components.

[0092] The cover tape 10 constituting the electronic component packaging 100 of this embodiment is highly transparent, and therefore the electronic component packaging 100 of this embodiment has excellent visibility of the stored electronic components.

[0093] More specifically, an electronic component package in which the sealant layer 2 of the cover tape 10 is adhered to the carrier tape so as to seal the electronic component can be obtained by the following procedure. (1) A carrier tape 20 having electronic components housed in recesses is prepared. (2) Using the cover tape 10, the entire opening of the carrier tape is covered (at this time, the sealant layer 2 is in contact with the carrier tape). (3) Apply heat sealing treatment.

[0094] The specific method and conditions for heat sealing are not particularly limited as long as the cover tape 10 is sufficiently strongly adhered to the carrier tape 20. Typically, a known taping machine is used, and the heat sealing can be carried out at a temperature of 100 to 240°C, a load of 0.1 to 10 kgf (0.98 to 98 N), and a time of 0.0001 to 1 second.

[0095] The obtained electronic component package is wound, for example, on a reel and then transported to a work area where the electronic components are mounted on an electronic circuit board, etc. The reel may be made of metal, paper, plastic, or the like. After the electronic component package has been transported to the work area, the cover tape 10 is peeled off from the carrier tape 20, and the housed electronic components are taken out.

[0096] The electronic components to be accommodated are not particularly limited, and examples thereof include general components used in the manufacture of electrical and electronic devices, such as semiconductor chips, transistors, diodes, capacitors, piezoelectric elements, optical elements, LED-related components, connectors, and electrodes.

[0097] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. [Example]

[0098] [Example 1] An adhesive (product name: TM-2314, manufactured by Toyo Ink Co., Ltd.) was applied to a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., Espet (registered trademark) E5100, thickness 12 μm) that served as the base layer so that the adhesive layer was 2 μm thick, and low-density polyethylene (product name: Sumikathen (registered trademark) L705, manufactured by Sumitomo Chemical Co., Ltd., thickness 35 μm, density 0.919 g / cm) was applied to the side on which the adhesive layer was formed. 3 ) was extrusion laminated at an extrusion temperature of 200°C to form a film having a thickness of 35 μm, and dried at 90°C to form an intermediate layer. Next, an emulsion of styrene-based sealant resin (product name: Nipol (registered trademark) LX2507H, manufactured by Zeon Corporation, viscosity 50 mPa·s) was applied to the surface of the intermediate layer and dried at 70°C to form a sealant layer with a thickness of 2 μm, thereby obtaining a cover tape.

[0099] [Example 2] As an intermediate layer, a low-density polyethylene film E605M (manufactured by Tamapoly Co., Ltd., thickness 35 μm, density 0.920 g / cm ) was used on the side where the adhesive layer was formed. 3 A cover tape was obtained in the same manner as in Example 1, except that the above-mentioned 1, 2, 3 and 4 were laminated.

[0100] [Example 3] The low-density polyethylene film used as the intermediate layer was Unilux LS-744C (manufactured by Idemitsu Unitech Co., Ltd., thickness 40 μm, density 0.920 g / cm 3 A cover tape was obtained in the same manner as in Example 2, except that the above-mentioned step (2) was changed to the above-mentioned step (2).

[0101] [Comparative Example 1] The low-density polyethylene film used as the intermediate layer was TUX VCS (Mitsui Chemicals Tocello, thickness 40 μm, density 0.920 g / cm 3 A cover tape was obtained in the same manner as in Example 2, except that the above-mentioned step (2) was changed to the above-mentioned step (2).

[0102] Comparative Example 2 The low-density polyethylene film used as the intermediate layer was LL-XLTN (Futamura Chemical Co., Ltd., thickness 40 μm, density 0.920 g / cm 3 A cover tape was obtained in the same manner as in Example 2, except that the above-mentioned step (2) was changed to the above-mentioned step (2).

[0103] [Surface roughness of the intermediate layer film (maximum height R z )] Maximum height R of the surface of the intermediate film on the substrate layer side z was measured using a non-contact surface / layer cross-sectional shape measurement system (Vertscan 2.0 (R3300HL), manufactured by Ryoka Systems Co., Ltd.). The maximum height of the surface of the intermediate layer film on the base layer side measured by the above method is shown in Table 1.

[0104] [Area 3000μm 2 Ultra 10000μm 2 Air bubbles below 1cm 2 [Number of pieces per The procedure for counting the number of bubbles is described below. Here, Fig. 3(A) is a schematic diagram showing a method for observing bubbles. (B) is an enlarged view of (A). Fig. 3(B) is an enlarged view of Fig. 3(A). Both Fig. 3(A) and (B) correspond to the cover tape of this embodiment observed from the sealant layer 2 side. (1) First, as shown in Figure 3(A) and Figure 3(B), a 1mm hole is placed on the center line L of the cover tape, 100 mm inward from the short side S of the cover tape. 2 The four bubble observation areas A1 were selected. (2) Next, as shown in Figure 3(B), a 1 mm bubble is placed on the center line L of the cover tape at a distance of 5 mm from the bubble observation area A1. 2 The bubble observation area A2 was selected on all four sides. Similarly, on the center line L of the cover tape, 1 mm apart from the bubble observation areas A2 to A9 at intervals of 5 mm each were selected. 2 The four bubble observation areas A3 to A10 were selected. (3) Each of the bubble observation areas A1 to A10 was observed at a magnification of 200x using a microscope from the sealant layer side of the cover tape, and a rectangle was drawn where the periphery of the observed bubble was in contact, and the area of ​​the rectangle was taken as the area of ​​the bubble. (4) For each of the bubble observation regions A1 to A10, the area calculated by the method is 3000 μm 2 Ultra 10000μm 2 The number of bubbles that were below the specified value was counted. (5) Area of ​​3000 μm observed in bubble observation areas A1 to A10 2 Ultra 10000μm 2 The total number of bubbles below is 10mm 2 The number of bubbles per 10 mm 2 Multiplying the number of bubbles per 10 gives a value of 100mm. 2 (1cm 2 ) was used as the number of bubbles. The number of bubbles counted by the above method is shown in Table 1.

[0105] [Area 100μm 2 More than 3000μm 2 Air bubbles below 1cm 2 [Number of pieces per 3000μm 2 Ultra 10000μm 2 Air bubbles below 1cm 2 The areas A1 to A10 were selected in the same way as for the number of bubbles per area, and the area of ​​the bubbles was calculated. 2 More than 3000μm 2 The following bubbles were counted: Area of ​​100 μm observed in each of the regions A1 to A10 2 More than 3000μm 2 The total number of bubbles below is 10mm 2 The number of bubbles per 10 mm 2 Multiplying the number of bubbles per 10 gives a value of 100mm. 2 (1cm 2 ) was used as the number of bubbles. The number of bubbles counted by the above method is shown in Table 1.

[0106] [Visibility evaluation] Letters were printed on A4-size plain paper in 6-point font size, and the resulting cover tape was placed on the printed surface to create a sample for visibility evaluation. The flat visibility evaluation sample was then visually observed from 30 cm above. Evaluation was performed by three evaluators, who scored the samples according to the following criteria and then added up the scores. The results are shown in Table 1. 2: Can read all printed text 1: Some printed characters can be read 0: The printed text is completely unreadable

[0107] [Table 1]

[0108] The cover tapes of the examples had good results in the visibility evaluation. From this, it can be understood that the cover tape according to the present embodiment has high transparency and provides excellent visibility of the contents, such as stored electronic components. [Explanation of symbols]

[0109] 1 Base material layer 2 Sealant Layer 10 Cover Tape 20 Carrier tape 21 Pocket 100 Electronic component packaging body L Center line of cover tape S Short side of cover tape A1~A10 Bubble observation area

Claims

1. A method for manufacturing a cover tape for packaging electronic components, comprising: the cover tape includes a base layer, a sealant layer provided on one side of the base layer, and an intermediate layer provided between the base layer and the sealant layer; The method for manufacturing the cover tape includes: (1) preparing a film corresponding to the base layer; (2) preparing a film corresponding to the intermediate layer; (3) applying an adhesive material to one side of the prepared film corresponding to the base layer, and laminating the film corresponding to the intermediate layer; (4) applying the sealant layer-forming coating liquid to the exposed surface of the film corresponding to the intermediate layer to form the sealant layer; Including, A method for manufacturing a cover tape, wherein the maximum height Rz of the surface of the film corresponding to the intermediate layer that is in contact with the film corresponding to the base layer is 5 μm or less.

2. The method for manufacturing a cover tape according to claim 1, wherein the number of bubbles having an area of ​​more than 3000 μm 2 and not more than 10000 μm 2 observed from the sealant layer side is not more than 1000 per cm 2 .

3. The method for manufacturing a cover tape according to claim 1 or 2, wherein the number of bubbles having an area of ​​100 μm 2 or more and 3000 μm 2 or less observed from the sealant layer side is 500 or less per cm 2 .

4. A method for manufacturing a cover tape described in any one of claims 1 to 3, wherein the base material layer contains a polyester-based resin.

5. A method for manufacturing a cover tape described in any one of claims 1 to 4, wherein the sealant layer contains a styrene-based resin and / or a (meth)acrylic-based resin.

6. The method for manufacturing a cover tape according to claim 1, wherein the intermediate layer contains an ethylene-based resin having a density of 0.880 g / cm 3 or more and 0.940 g / cm 3 or less.

7. A method for manufacturing a cover tape described in any one of claims 1 to 6, wherein the cover tape is a laminated body.

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