JP2019064640A - Resin composition and cover tape - Google Patents

Abstract

To provide a cover tape capable of preventing sticking of an electronic component and easily peeled from a carrier tape, and a resin composition for manufacturing such a cover tape.SOLUTION: The resin composition used for a sealant layer of a cover tape for an electronic component is characterized in that the methyl acrylate content of an (A) ethylene-methyl acrylate copolymer is 10 mol%-17 mol% with respect to the (A) ethylene-methyl acrylate copolymer, the (meth)acrylate content of a (C) a styrene-(meth)acrylate copolymer is 45 mol%-80 mol% with respect to the (C) a styrene-(meth)acrylate copolymer, and the melt flow rate(MFR) of the (C) a styrene-(meth)acrylate copolymer is 8 g/10 min. to 30 g/10 min., by 3.8 kg at 230°C.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a resin composition and a cover tape. More particularly, the present invention relates to a resin composition for use in a sealant layer of a cover tape for packaging electronic components, and a cover tape provided with a sealant layer formed of the resin composition.

  After production, electronic components such as semiconductor IC chips are stored in packaging materials to prevent contamination before being provided to the mounting process, and stored in a state of being wound on paper or plastic reels And transported. In the packaging of this electronic component, a tape-like packaging material is used so as to correspond to the mounting process to the substrate by the automatic mounting apparatus, and the packaging material is spaced apart from the long sheet by a predetermined distance. The carrier tape comprises a plurality of concave storage pockets and a cover tape which is heat sealed to the carrier tape. After the electronic components are accommodated in the storage pocket of the carrier tape, a cover tape as a lid material is superimposed on the upper surface of the carrier tape, and both ends of the cover tape are heat sealed continuously in the length direction with a heated seal bar. The electronic component package is

  Electronic components such as IC (Integrated Circuit), LSI (Large Scale Integrated Circuit), LED (Light Emitting Diode), etc. packaged in sealing resin etc. are heated when soldering after mounting if the sealing resin absorbs moisture. In the process, a crack of the sealing resin, which is called a solder crack, may occur, and it is necessary to perform a baking process to remove moisture contained in the sealing resin. In order to improve the mass productivity of such electronic components, it is necessary to raise the baking temperature and shorten the baking time. In recent years, a cover tape may be heat-sealed on a carrier tape, and baking processing may be performed for about 24 to 72 hours in an environment of 60 to 80 ° C. On the other hand, in the cover tape, the heat seal layer which is the outermost layer of the cover tape thermally bonded to the carrier tape in order to heat seal the carrier tape in a short time to improve the productivity. Plastic resins are used. Therefore, in the case of the conventional cover tape, there is a case that the storage component adheres to the heat seal layer by the baking process under the above conditions. Moreover, the peeling strength at the time of peeling a cover tape from a carrier tape may increase by this baking process, and a cover tape may be cut.

  As a measure for adhesion of electronic components by baking, for example, in Patent Document 1, a thermoplastic resin comprising at least a base layer, an intermediate layer, and a heat seal layer and having an acid value of 1 to 20 mg KOH / g constituting the heat seal layer. 25 to 50 parts by mass of an inorganic filler having a median diameter (D50) of less than 50 nm and 20 to 60 parts by mass of an inorganic filler having a median diameter (D50) of 50 to 300 nm based on 100 parts by mass Cover tapes have been proposed. In Patent Document 1, by including an inorganic filler in the heat seal layer, at the same time as having good sealability to a carrier tape made of a thermoplastic resin and at the same time heat-sealed, baking is performed at 60 to 80 ° C. Provided is a cover tape which does not adhere to the cover tape and which is less likely to be broken when peeled off.

JP, 2011-225263, A

  However, the cover tape proposed in Patent Document 1 has a complicated manufacturing process and can not be heat-sealed at a lower temperature. In addition, when the baking process is performed in a state where the cover tape is heat-sealed on the carrier tape, there are cases where the electronic parts adhere to the cover tape and the electronic parts can not be taken out.

  According to the present invention, even when baking is performed with the cover tape heat-sealed to the carrier tape, the contained electronic components do not adhere to the cover tape, and the cover tape is peeled off from the carrier tape after the baking process. Providing a cover tape having good releasability, and a resin composition used for producing such a cover tape.

  As a result of intensive studies, the present inventors can prevent the adhesion of electronic components by adjusting the composition of the resin composition constituting the heat seal layer, and at the same time, easily peel off the carrier tape. It has been found that the present invention is obtained.

According to the present invention, there is provided a resin composition for use in a sealant layer of a cover tape for packaging electronic components, comprising:
The resin composition is
(A) ethylene-methyl acrylate copolymer,
(B) antistatic resin,
(C) a styrene- (meth) acrylate copolymer,
The amount of the (A) ethylene-methyl acrylate copolymer is 60 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the resin composition,
The (B) antistatic resin is 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin composition.
The amount of the (C) styrene- (meth) acrylate copolymer is 15 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin composition,
The methyl acrylate content of the (A) ethylene-methyl acrylate copolymer is 10 mol% or more and 17 mol% or less with respect to the entire (A) ethylene-methyl acrylate copolymer,
The (meth) acrylate content of the (C) styrene- (meth) acrylate copolymer is 45 mol% or more and 80 mol% or less with respect to the entire (C) styrene- (meth) acrylate copolymer,
The resin composition is provided wherein the melt flow rate (MFR) of the (C) styrene- (meth) acrylate copolymer at 230 ° C. and 3.8 kg is 8 g / 10 min or more and 30 g / 10 min or less.

Further, according to the present invention, it is a cover tape for electronic component packaging, comprising a sealant layer comprising the above resin composition, and a base material layer, wherein the cover tape has a dimension of 5.5 mm in width, A carrier tape (conductive polycarbonate carrier tape, “No. 3000” manufactured by 3M Corporation) with a width of 8 mm and a temperature of 180 ° using a double-edged iron with a width of 0.4 mm and a length of 32 mm. The cover tape has a peeling strength of 15 g or more and 40 g or less when heat sealed under the conditions of a carrier tape feed pitch of 8 mm and a load according to JIS C 0806-3. A cover tape is provided.
The heat sealing conditions used for measurement of peeling strength in this embodiment are as follows.
Equipment: ISMECA MBM4000 (made by ISMECA)
Iron size: 0.4 mm × 32 mm (two blades)
Temperature: 180 ° C
Load: 1 kg
Sealing time: 100 ms Carrier tape feed pitch: 8 mm
Carrier tape: Conductive polycarbonate ("No. 3000" manufactured by 3M Corporation).

  ADVANTAGE OF THE INVENTION According to this invention, while preventing adhesion of an electronic component, the cover tape which is easy to peel from a carrier tape, and the resin composition for manufacturing such a cover tape are provided.

It is a sectional view showing the composition of the cover tape concerning this embodiment. It is a figure which shows an example of the state which sealed the cover tape for electronic component packing which concerns on this embodiment on a carrier tape.

  The cover tape 10 which concerns on this embodiment contains the base material layer 3 and the sealant layer 2 provided in one side of the base material layer 3, as shown in FIG. Here, the cover tape 10 may have a two-layer structure of base material layer 3 / sealant layer 2, or, for example, the intermediate layer 1 which is another layer between the base material layer 3 and the sealant layer 2. It may be a multilayer structure such as substrate layer 3 / intermediate layer 1 / sealant layer 2 interposed.

  Here, a method of using the cover tape will be described with reference to FIG. As shown in FIG. 2, the cover tape 10 is used as a cover material of the carrier tape 20 in which concave pockets 21 are continuously provided in accordance with the shape of the electronic component. Specifically, the cover tape 10 is used by bonding (heat sealing) to the surface of the carrier tape 20 so as to cover the entire opening of the pocket 21 of the carrier tape 20. In the following description, a structure obtained by bonding the cover tape 10 and the carrier tape 20 is referred to as an electronic component package 100.

  In the manufacturing site of the electronic device, the electronic component is accommodated in the pocket 21 of the carrier tape 20, and then the cover tape 10 is adhered to the surface of the carrier tape 20 so as to cover the entire opening of the pocket 21 of the carrier tape 20. By doing this, the package 100 in which the electronic component is accommodated is manufactured. As described above, the package 100 is transported to a working area for surface mounting on an electronic circuit board or the like in a state where the package 100 is wound around a paper or plastic reel as described above. In the surface mounting process of the electronic component, the cover tape 10 is peeled off from the carrier tape 20, and the electronic component is automatically taken out of the package and mounted on the electronic circuit substrate.

In the present embodiment, as the resin composition constituting the sealant layer 2,
(A) ethylene-methyl acrylate copolymer,
(B) antistatic resin,
A composition comprising (C) a styrene- (meth) acrylate copolymer is used.
In the above components, the (A) ethylene-methyl acrylate copolymer is in an amount of 60 parts by mass to 70 parts by mass with respect to 100 parts by mass of the resin composition,
(B) The antistatic resin is 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin composition,
The amount of the (C) styrene- (meth) acrylate copolymer is 15 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin composition.
Furthermore, the methyl acrylate content of the (A) ethylene-methyl acrylate copolymer is 10 mol% or more and 17 mol% or less with respect to the entire (A) ethylene-methyl acrylate copolymer,
The (meth) acrylate content of the (C) styrene- (meth) acrylate copolymer is 45 mol% or more and 80 mol% or less with respect to the entire (C) styrene- (meth) acrylate copolymer,
The melt flow rate (MFR) of the styrene- (meth) acrylate copolymer (C) at 230 ° C. and 3.8 kg is 8 g / 10 min or more and 30 g / 10 min or less.

  By using the resin composition of the above composition, the sealant layer 2 obtained from the composition is suppressed from sticking of the electronic component, and the heat sealability to the carrier tape 20 is good, and from the carrier tape 20 It has good peelability.

  The resin composition of the present embodiment contains (A) an ethylene-methyl acrylate copolymer, and the component (A) is an amount of 60 parts by mass to 70 parts by mass with respect to 100 parts by mass of the resin composition. . By using the component (A) in the above-described range, the heat sealability of the obtained cover tape 10 with respect to the carrier tape 20 can be made a preferable range, and sticking of the electronic component is suppressed. The (A) ethylene-methyl acrylate copolymer is a copolymer of ethylene and methacrylic acid, and the methyl acrylate content in the component (A) is 10 mol% or more with respect to the entire component (A). It is less than mol%. Here, the methyl acrylate content in the component (A) refers to the proportion (mol%) of the methyl acrylate-derived structural unit contained in the ethylene-methyl acrylate copolymer (A). By being a methyl acrylate content rate of the above-mentioned range, sticking of an electronic component to career tape 20 obtained from a resin composition containing this can be controlled. As the ethylene-methyl acrylate copolymer (A), one type may be used alone, or two or more types may be used in combination. When (A) ethylene-methyl acrylate copolymer is used in combination of 2 or more types, the average value of the methyl acrylate content which they have is 10 mol% with respect to the whole (A) ethylene methyl acrylate copolymer. It is used so as to be 17 mol% or less.

  The composition of the present embodiment contains (B) an antistatic resin, and the amount of the component (B) is 10 parts by mass or more and 20 parts by mass or less, preferably 12 parts by mass with respect to 100 parts by mass of the resin composition. It is the quantity of 18 parts by mass or less. By using the antistatic resin in the above-mentioned range, antistatic performance can be imparted to the obtained sealant layer 2.

  As the antistatic resin, lithium ion-containing polymer type antistatic resin, polyamide-based copolymer such as polyether ester amide, block polymer of polyolefin and polyether, polymer composed of polyethylene ether and glycol, carboxylic acid group-containing such as potassium ionomer These include polymers, quaternary ammonium base-containing copolymers, metal fillers such as tin oxide, zinc oxide and titanium oxide, and thiophene-based conductive polymers such as polyethylenedioxythiophene / polystyrene sulfonic acid (PEDOT / PSS). It is not limited to. These antistatic resins preferably have a thermal decomposition temperature of 120 ° C. or higher in order to prevent deterioration or the like due to high temperature at the time of extrusion lamination or heat sealing.

  The resin composition of the present embodiment includes (C) a styrene- (meth) acrylate copolymer, and the amount of the component (C) is 15 parts by mass to 25 parts by mass with respect to 100 parts by mass of the resin composition. Preferably, the amount is 17 parts by mass or more and 23 parts by mass or less. By using the component (C) in the above-mentioned range, the peel strength in the case of peeling the obtained cover tape 10 from the carrier tape 20 is easily prevented without breakage of the cover tape 10 or resin residue of the cover tape 10. It can be made to be peelable. The (C) styrene- (meth) acrylate copolymer is a copolymer of styrene and (meth) acrylic acid, and the (meth) acrylate content in the component (C) is the entire component (C) In contrast, it is 45 mol% or more and 80 mol% or less. Here, the (meth) acrylate content in the component (C) refers to the proportion (mol%) of the (meth) acrylate-derived structural unit contained in the styrene- (meth) acrylate copolymer (C). By being (meth) acrylate content rate of the above-mentioned range, carrier tape 20 obtained from a resin composition containing this is provided with good exfoliation nature. (C) Styrene- (meth) acrylate copolymerization may be used individually by 1 type, and may be used combining 2 or more types. (C) When using two or more types of styrene- (meth) acrylate copolymerization in combination, the average value of the (meth) acrylate content which they have is with respect to the whole (C) styrene-(meth) acrylate copolymerization And 45 mol% or more and 80 mol% or less.

  In the present embodiment, the (C) styrene- (meth) acrylate copolymer has a melt flow rate (MFR) at 230 ° C. and 3.8 kg of 8 g / 10 min or more and 30 g / 10 min or less. By using the styrene- (meth) acrylate copolymer which has a melt flow rate of the said range, the peelability of the sealant layer 2 obtained from the resin composition containing this becomes a suitable thing.

  The resin composition of the present embodiment may contain a tackifier resin, an antiblocking agent, a slip agent, and the like, as necessary.

  As the tackifying resin, for example, petroleum resin (aliphatic petroleum resin, aromatic petroleum resin, alicyclic petroleum resin obtained by hydrogenating the aromatic petroleum resin, etc.), rosin resin, terpene resin, styrene resin, coumarone · cumarone Inden resin etc. are mentioned. These tackifying resins can be used alone or in combination of two or more. In addition, when forming an adhesive bond layer by extrusion lamination, since it is melt-oxidized at high temperature, the point of stability with respect to oxidation to an alicyclic petroleum resin is especially preferable.

  Examples of antiblocking agents include silica, aluminosilicates (such as zeolite), and the like. By containing the antiblocking agent, blocking of the sealant layer 2 is alleviated.

  Examples of slip agents include palmitic acid amide, stearic acid amide, behenic acid amide, oleic acid amide, erucic acid amide, oleylpalmamide, stearylpalmamide, methylenebisstearylamide, methylenebisoleylamide, ethylenebisoleylamide, Various amides such as ethylene bis erucic acid amide, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, hydrogenated castor oil and the like can be mentioned. When the sealant layer 2 contains a slip agent, processability such as extrusion, release properties, film slip properties, etc. are improved.

  The sealant layer 2 produced from the resin composition of the present embodiment can be laminated on the base material layer 3 to obtain a cover tape. The thickness of the sealant layer 2 produced from the resin composition of the present embodiment is preferably 2 μm or more and 10 μm or less, and more preferably 3 μm or more and 8 μm or less. If the thickness of the sealant layer 2 is less than or equal to the above upper limit, it is easy to control the exudation during heat sealing, and if the thickness of the sealant layer 2 is more than or equal to the above lower limit, the cover The peel strength of the tape 10 to the carrier tape 20 is suitable.

In the cover tape 10 provided with the sealant layer 2 and the base material layer 3 produced from the resin composition of the present embodiment, the sealant layer 2 has a peel strength of at least 15 g with respect to the polycarbonate carrier tape when measured by the following measurement method. Less than 40g:
(Measuring method) A heat sealing machine is used to heat seal a cover tape having a dimension of 5.5 mm in width to a carrier tape having a width of 8 mm (conductive polycarbonate carrier tape, "No. 3000" manufactured by 3M Corporation). Let it be a test piece. The peel strength at the time of peeling a cover tape from a carrier tape is measured by the measuring method based on JISC0806-3.
(Heat sealing condition)
Heat sealing machine: ISMECA MBM4000 (made by ISMECA)
Iron size: 0.4 mm × 32 mm (two blades)
Seal temperature: 180 ° C
Seal load: 1 kg
Sealing time: 100 ms Carrier tape feed pitch: 8 mm
Carrier tape: Conductive polycarbonate ("No. 3000" manufactured by 3M Corporation).
(Peeling conditions (conform to JIS C 0806-3))
Peeling tester: GPD 856 VS (manufactured by GPD)
Peeling speed: 300 mm / min
Peeling angle: 175 ° to 180 °
The sealant layer 2 having the peel strength in the above-mentioned range does not adhere to the electronic components contained in the carrier tape 20 even after the baking process.

In the cover tape 10 provided with the sealant layer 2 and the base material layer 3 manufactured from the resin composition of the present embodiment, the residual rate of component adhesion when measured under the following conditions is 60% or less. If it is the said range, the electronic component accommodated in the carrier tape 20 will not adhere even after a baking process.
(Measurement conditions) A load of 2.8 ± 0.2 g / mm ² is applied to electronic components (10 pieces) in close contact with the sealant layer 2 and the electronic components are stored at 60 ° C. for 1 hour. Here, when the electronic component is used as an electronic component package, the surface in contact with the heat seal layer is generally in close contact with the sealant layer 2. After storage for 1 hour, vibration at 1500 rpm is applied for 1 minute, the number of electronic components remaining in close contact with the sealant layer 2 is counted, and the residual ratio (%) of component adhesion is determined from the following equation. Three measurements are taken and the average is determined.
Component sticking residual rate (%) = (number of remaining electronic parts / 10) × 100

  The material constituting the base material layer is added from the outside when the cover tape 10 is adhered to the carrier tape 20 when the sealant layer 2 is laminated to form the cover tape, or when the cover tape 10 is used. It is preferable to have mechanical strength that can withstand stress, and heat resistance that can withstand the heat history applied when bonding the cover tape 10 to the carrier tape 20. Moreover, the form of the material which comprises a base material layer is although it does not specifically limit, It is preferable that it is processed into a film form from a viewpoint which is easy to process.

  Specific examples of the material constituting the substrate layer 3 include polyester resins, polyamide resins, polyolefin resins, polyacrylate resins, polymethacrylate resins, polyimide resins, polycarbonate resins, ABS resins, etc. Be Among them, polyester resins are preferable from the viewpoint of improving the mechanical strength of the cover tape 10. In addition, nylon 6 may be used from the viewpoint of improving the mechanical strength and the flexibility of the cover tape 10. The base layer 3 may further contain a lubricant.

  The base material layer 3 may be formed of a single layer film containing the above-described material, or may be formed using a multilayer film including the above-described material in each layer. Moreover, as a form of the film used in order to form the base material layer 3, an unstretched film may be sufficient and the film extended | stretched uniaxially or biaxially may be sufficient, but, as for the cover tape 10 From the viewpoint of improving mechanical strength, the film is preferably uniaxially or biaxially stretched.

  The thickness of the base material layer 3 is preferably 5 μm or more, more preferably 10 μm or more. Moreover, the thickness of the base material layer 3 is preferably 50 μm or less, more preferably 40 μm or less. When the thickness of the base material layer 3 is equal to or less than the above upper limit, the cover tape 10 does not have too high rigidity and the cover tape 10 is applied even when torsional stress is applied to the carrier tape 20 after sealing. Can follow the deformation of the carrier tape 20 and can be prevented from peeling off. In addition, when the thickness of the base material layer 3 is equal to or more than the above lower limit value, the mechanical strength of the cover tape 10 can be made favorable, so when peeling the cover tape 10 from the carrier tape 20 at high speed, Breaking of the cover tape 10 can be suppressed.

  The total light transmittance of the base material layer 3 is preferably 80% or more, more preferably 85% or more. By doing this, in the package 100 comprising the cover tape 10 and the carrier tape 20 described later, it is necessary to be able to inspect whether the electronic components are properly accommodated in the pockets 21 of the carrier tape 20. Transparency can be provided. In other words, by setting the total light transmittance of the base material layer 3 to the above lower limit value or more, the electronic component housed in the inside of the package 100 consisting of the cover tape 10 and the carrier tape 20 can be It becomes possible to visually recognize from. In addition, it is possible to measure the total light transmittance of the base material layer 3 according to JISK7361-1 (1999).

  In one embodiment, an intermediate layer 1 may be provided between the substrate layer 3 and the sealant layer 2. By providing the intermediate layer 1, the cushioning properties of the entire cover tape 10 can be improved.

  The material which comprises the intermediate | middle layer 1 includes olefin resin, styrene resin, cyclic olefin resin, and the like. Among them, from the viewpoint of improving the cushioning properties of the entire cover tape, it is preferable to contain an olefin resin.

  When the intermediate layer is provided, the thickness is preferably 10 μm or more and 30 μm or less, more preferably 15 μm or more and 25 μm or less, from the viewpoint of improving the cushioning property of the entire cover tape.

  The cover tape of the present invention can be used for any of the carrier tapes known in the prior art.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

The following was used as ethylene-methyl acrylate copolymer (A).
· Ethylene-methyl acrylate copolymer (a1): "Aclift CG4002" manufactured by Sumitomo Chemical Co., Ltd. (methyl acrylate content: 28 mol%)
・ Ethylene-methyl acrylate copolymer (a2): Mitsui-Dupont Polychemicals Co., Ltd. "Elvaroy AC1820" (methyl acrylate content: 20 mol%)
Ethylene-methyl acrylate copolymer (a3): “Rex Pearl EB 230 X” manufactured by Nippon Polyethylene Co., Ltd. (methyl acrylate content: 14 mol%)
Ethylene-methyl acrylate copolymer (a4): “Rexpearl EB330H” manufactured by Nippon Polyethylene Co., Ltd. (methyl acrylate content: 12 mol%)
-Ethylene-methyl acrylate copolymer (a5): Mitsui-Dupont Polychemical Co., Ltd. "Elvaroy AC 1609" (methyl acrylate content: 9 mol%)

The following was used as ethylene-ethyl acrylate copolymer (A ').
-Ethylene-ethyl acrylate copolymer (a6): "NUC 6170" manufactured by NUC Co., Ltd. (ethyl acrylate content: 18 mol%)
-Ethylene-ethyl acrylate copolymer (a7): "NUC 6220" manufactured by NUC Co., Ltd. (ethyl acrylate content: 7 mol%)
· Ethylene-ethyl acrylate copolymer (a8): "EERN 023" manufactured by NUC Co., Ltd. (ethyl acrylate content: 13 mol%)

The following were used as antistatic resin (B).
· Antistatic resin (b1): "Perektron PVH" (PP-PEG block copolymer) manufactured by Sanyo Chemical Industries, Ltd.

The following was used as a styrene- (meth) acrylate copolymer (C).
-Styrene-(meth) acrylate copolymer (c1): "Estyrene MS-750" (the (meth) acrylate content rate: 75%) made by Nippon Steel & Sumikin Chemical Co., Ltd.
-Styrene- (meth) acrylate copolymer (c3): "Estyrene MS-600" (content of (meth) acrylate: 60%) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
-Styrene- (meth) acrylate copolymer (c5): "Estyrene MS-500" (content of (meth) acrylate: 50%) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
-Styrene- (meth) acrylate copolymer (c6): "Estyrene MS-300" (content of (meth) acrylate: 30%) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.
The following was used as a methacrylic resin (C ').
・ Methacrylic resin (c4): "Sumipex LG2" manufactured by Sumitomo Chemical Co., Ltd.
・ Methacrylic resin (c2): "Sumipex MGSV" manufactured by Sumitomo Chemical Co., Ltd.

(Examples 1 to 8 and Comparative Examples 1 to 10)
As shown in Table 1, 65 parts by mass of ethylene-methyl acrylate copolymer (A) as an adhesive resin, styrene-methyl (meth) acrylate copolymer (C) as a cohesion adjustment resin, and charging The antistatic resin (B) as an inhibitor was kneaded with a twin-screw extruder to obtain a resin composition for forming a sealant layer. A PET film with a film thickness of 16 μm (E5102 manufactured by Toyobo Co., Ltd.) is used as the base layer, and a low density polyethylene (Pesorosen 203 manufactured by Tosoh Corp.) as the intermediate layer is extruded thereon by an extrusion laminating method. The resin composition was formed into a film having a thickness of 20 μm at ° C. and further formed as an adhesive layer on the formed intermediate layer to a film thickness of 5 μm at an extrusion temperature of 200 ° C. by extrusion lamination.

The obtained cover tape was evaluated on the following items. The evaluation results are shown in Table 1.
(Parts sticking residual rate)
A load of 2.8 ± 0.2 g / mm ² was applied to the electronic parts (10 pieces) adhered to the sealant layer, and the electronic parts were stored at 60 ° C. for 1 hour. Here, when the electronic component is used as an electronic component package, the surface which is usually in contact with the heat seal layer is in close contact with the sealant layer. After storage for 1 hour, vibration at 1500 rpm was applied for 1 minute, the number of electronic parts remaining in close contact with the sealant layer was counted, and the part adhesion remaining rate (%) was determined from the following equation. The measurement was performed three times and the average was calculated.
Component sticking residual rate (%) = (number of remaining electronic parts / 10) × 100
The results are shown in Table 1.

(Peeling strength to polycarbonate carrier tape)
Evaluation of peeling strength was performed according to the peeling test based on JISC0806-3. The cover tape obtained by the method described above is sized to a width of 5.5 mm, and a heat sealing machine is used for a carrier tape having a width of 8 mm (conductive polycarbonate carrier tape, "No. 3000" manufactured by 3M Corporation) The sample was heat sealed to give a test piece. Peeling strength at the time of peeling a cover tape from a carrier tape was measured by the measuring method based on JISC0806-3.
(Heat sealing condition)
Heat sealing machine: ISMECA MBM4000 (made by ISMECA)
Iron size: 0.4 mm × 32 mm (two blades)
Seal temperature: 180 ° C
Seal load: 1 kg
Sealing time: 100 ms Carrier tape feed pitch: 8 mm
Carrier tape: Conductive polycarbonate ("No. 3000" manufactured by 3M Corporation).
(Peeling conditions (conform to JIS C 0806-3))
Peeling tester: GPD 856 VS (manufactured by GPD)
Peeling speed: 300 mm / min
Peeling angle: 175 ° to 180 °

(Cohesive force)
The sealant surfaces of the two cover tapes were put together, heat bonded with a heat sealer, and the load when peeling off the bonded surface was measured as cohesion.
(Heat sealing condition)
Heat sealing machine: Auto cup sealer seal width: 10 mm × 200 mm
Seal temperature: 180 ° C
Sealing time: 1.0 seconds Sealing load: 1.5 kg
(Peeling conditions)
Equipment: TENSILON Peeling angle: Free peeling speed: 300 mm / min

(Peeling appearance)
The surface of the carrier tape after measurement of peel strength was observed with a microscope at 20 to 50 times, and the following criteria were scored for reference.
(Standard)
0 point: interfacial peeling.
1 point: Cohesive failure in one third or less of the seal width.
2 points: Cohesive failure in 2/3 or less of the seal width.
3 points: cohesive failure on the entire surface. Partially missing. In the center there is an outbreak of rash.
4 points: cohesive failure on the entire surface. Partially missing. Mottled condition.
5 points: Cohesive failure, but width is not stable. Not mottled.
6 points: cohesive failure on the entire surface. At the end there is a generation of fluff over the width of the iron
7 points: cohesive failure on the entire surface. There are ten or more minute bumps at the end.
8 points: cohesive failure on the entire surface. Less than 10 tiny bumps.
9 points: cohesive failure on the entire surface. There is no minute skin.

  As shown in the above table, all the cover tapes of the examples have low residual rates of component sticking, good releasability at the time of peeling from the carrier tape, and are suitable as a cover tape for electronic component packaging without problems. It could be used for

1 Intermediate Layer 2 Sealant Layer 3 Substrate Layer 10 Cover Tape for Electronic Component Packaging (Cover Tape)
20 Carrier Tape 21 Pocket 100 Electronic Component Package

Claims (3)

A resin composition for use in a sealant layer of a cover tape for packaging electronic components, comprising:
The resin composition is
(A) ethylene-methyl acrylate copolymer,
(B) antistatic resin,
(C) a styrene- (meth) acrylate copolymer,
The amount of the (A) ethylene-methyl acrylate copolymer is 60 parts by mass or more and 70 parts by mass or less with respect to 100 parts by mass of the resin composition,
The (B) antistatic resin is 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin composition.
The amount of the (C) styrene- (meth) acrylate copolymer is 15 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of the resin composition,
The methyl acrylate content of the (A) ethylene-methyl acrylate copolymer is 10 mol% or more and 17 mol% or less with respect to the entire (A) ethylene-methyl acrylate copolymer,
The (meth) acrylate content of the (C) styrene- (meth) acrylate copolymer is 45 mol% or more and 80 mol% or less with respect to the entire (C) styrene- (meth) acrylate copolymer,
The resin composition whose melt flow rate (MFR) in 230 degreeC and 3.8 kg of said (C) styrene- (meth) acrylate copolymer is 8 g / 10min-30 g / 10min. A cover tape for packaging electronic parts, comprising a sealant layer comprising the resin composition according to claim 1 and a base material layer,
The cover tape is dimensioned 5.5 mm in width, and it is combined with a carrier tape (conductive polycarbonate carrier tape, "No. 3000" manufactured by 3M Corporation) having a width of 8 mm, and the single blade has a width of 0.4 mm and a length Heat sealing using a double-edged iron with dimensions of 32 mm, temperature 180 ° C., load 1 kg, 100 ms, carrier tape feed pitch 8 mm, and measurement according to the test method according to JIS C 0806-3, The cover tape whose peeling strength of the said cover tape is 15g-40g. The cover tape according to claim 2, wherein a residual rate of component sticking determined by the following measurement method of the sealant layer is 60% or less.
(Measuring method) Ten electronic parts are put on the sealant layer, and a load of 2.8 ± 0.2 g / mm 2 is applied and kept at 60 ° C. for 1 hour, then the cover tape is vibrated at 1500 rpm for 1 minute. Count the number of electronic components remaining in intimate contact with the sealant layer, and determine the component sticking residual ratio from the following equation;
Component sticking residual rate (%) = (number of remaining electronic parts / 10) × 100

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