JPH05311130A - Tape for setting electronic components side by side - Google Patents

Abstract

PURPOSE:To provide the tape for setting electronic components side by side, capable of saving a solvent for forming the pressure-sensitive adhesive layer curable with radiation and excellent in adhesion and holding force for electronic components and excellent in maintenance of the reed screen-shaped arrangement of the electronic components or support of the electronic components in place. CONSTITUTION:This tape for setting electronic components side by side is a tape for keeping the reed screen-shaped arrangement of the electronic components through the lead wires by a pressure-sensitive adhesive layer formed on the base material. The pressure-sensitive adhesive layer is composed of a radiation curable type pressure-sensitive adhesive containing 100 pts.wt. acrylic polymer containing a structural unit derive from an acrylic monomer represented by a general formula: CH2=C(R<1>)COOR<2> (Provided that R<1> is hydrogen or methyl group and R<2> is a 2 to 14C alkyl group) in an amount of >=50wt.%, 50 to 150 pts.wt. fusible resin exhibiting 70 to 200 deg.C melting point and 1 to 30 pts.wt. polyfunctional monomer having two or more radiation-sensitive unsaturated bonds in the molecule.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape for connecting electronic parts, which can be firmly bonded and held through its lead wires by heating at low temperature for a short time.

[0002]

2. Description of the Related Art Conventionally, a pressure-sensitive adhesive has been used as a tape for connecting electronic components for holding and arranging electronic components in a sloping manner through lead wires by a pressure-sensitive adhesive layer provided on a supporting substrate. It has been known that the layer is formed of a pressure-sensitive adhesive having a pressure-sensitive adhesive having a strong adhesive strength at room temperature and a hot-melt resin to improve the holding power such as creep characteristics (Japanese Patent Publication No. 56-
13040). However, it is necessary to coat the pressure-sensitive adhesive in a large amount of organic solvent on a supporting base material and process it into a tape for connecting electronic components, which is a problem in terms of environmental hygiene and safety. There was a problem.

On the other hand, in view of the above-mentioned problems, a tape for connecting electronic parts has been proposed which uses a solventless coating type radiation-curable pressure-sensitive adhesive which can be coated with no solvent or using a small amount of solvent. There is. Such a radiation-curable pressure-sensitive adhesive has the advantage of being superior in water resistance and heat resistance as compared with emulsion-type and hot-melt type adhesives. However, the cohesive strength of conventional tapes for connecting electronic components using radiation-curable pressure-sensitive adhesives that use solvent-saving coating pressure-sensitive adhesives with a low-molecular-weight base polymer Of the pressure-sensitive adhesive of the solvent-saving coating diluted with the reactive monomer, there is a problem that the adhesive strength of the electronic component is poor. Therefore, in any case, it causes a positional shift or a drop-out problem of the electronic component.

When a heat-melting resin is blended with a conventional radiation-curable pressure-sensitive adhesive to form a tape for connecting electronic parts, the pressure-sensitive adhesive layer is impeded by the radiation-induced cross-linking treatment to cohesive force. And the holding power of electronic parts was poor. Therefore, in any case, it is difficult to obtain a tape for connecting electronic components, which satisfies both the adhesive force and the holding force of the electronic components while satisfying the solvent-saving coating.

[0005]

DISCLOSURE OF THE INVENTION According to the present invention, a pressure-sensitive adhesive layer can be formed by coating without using a solvent or using a small amount of solvent, and the pressure-sensitive adhesive layer exhibits radiation-curability and adheres to electronic parts. The subject is to develop a tape for connecting electronic components, which has excellent strength and holding power.

[0006]

DISCLOSURE OF THE INVENTION The present invention is a tape for arranging and holding an electronic component in a sloping manner through its lead wire by a pressure-sensitive adhesive layer provided on a supporting base material. The adhesive layer has a general formula: CH ₂ = C (R ¹ ) COOR
² (However, R ¹ is hydrogen or a methyl group, and R ² has ² carbon atoms.
~ 14 alkyl groups. ) 100 parts by weight of an acrylic polymer containing 50% by weight or more of an acrylic monomer unit, 50 to 150 parts by weight of a heat-meltable resin having a melting point of 70 to 200 ° C., and a radiation-reactive It is intended to provide a tape for connecting electronic parts, characterized by comprising a radiation-curable heat-sensitive pressure-sensitive adhesive containing 1 to 30 parts by weight of a polyfunctional monomer having two or more saturated bonds.

[0007]

The pressure-sensitive adhesive having the above composition can be applied without solvent or using a small amount of solvent, and the formed pressure-sensitive adhesive layer is cured by irradiation of radiation, and electronic parts can be easily prepared at room temperature before heat treatment. Adhesive property that can be temporarily fastened to, firmly develops a strong adhesive force by heating, firmly adheres electronic parts, and increases the holding force with a decrease in temperature, and holds the adhered electronic parts with almost no displacement. Indicates.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION The tape for connecting electronic parts of the present invention comprises a support base layer comprising a radiation-curable heat-sensitive pressure-sensitive adhesive containing an acrylic polymer, a heat-meltable resin and a polyfunctional monomer. The pressure-sensitive adhesive layer is provided on the material to hold the electronic components in a sloping arrangement through the lead wires.

The radiation-curable heat-sensitive pressure-sensitive adhesive used in the present invention has the general formula: CH ₂ ═C (R ¹ ) COOR ²
(However, R ¹ is hydrogen or a methyl group, and R ² has ^{2 to 2} carbon atoms.
14 alkyl groups. ) An acrylic polymer containing 50% by weight or more of an acrylic monomer unit represented by (4) is used as a component. The acrylic polymer preferably used in terms of adhesive properties such as cohesive strength and solvent-saving coating properties has a weight average molecular weight of 50,000 to 500,000, and particularly 100,000 to 300,000.

Specific examples of the acrylic monomer units include alkyl groups such as ethyl group, propyl group, butyl group, isobutyl group, isoamyl group, hexyl group, 2-ethylhexyl group, isooctyl group, isononyl group and isodecyl group. Examples thereof include esters of acrylic acid and methacrylic acid having

The acrylic polymer may be prepared by using 50 to 100% by weight of one or more acrylic monomers. Examples of other monomer units that the acrylic polymer may contain for the purpose of controlling the holding power include acrylic acid, methacrylic acid, acrylamide, methacrylamide, acrylonitrile, vinyl acetate, styrene, N-vinylpyrrolidone, and N. -Methylol acrylamide, glycidyl acrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid 2
-Hydroxyethyl, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and the like can be mentioned.

The acrylic polymer may have a radiation-reactive unsaturated bond for the purpose of improving crosslinkability.
The introduction of the radiation-reactive unsaturated bond is, for example, a hydroxyl group or a carboxyl group in an acrylic polymer,
A method of reacting a monomer having a functional group capable of reacting with a functional group such as an amino group and a radiation-reactive unsaturated bond, for example, glycidyl acrylate, glycidyl methacrylate, 2-methacryloyloxyethyl isocyanate with an acrylic polymer, Alternatively, it can be carried out by a method of preparing an acrylic polymer by a radical polymerization method in combination with a compound having two or more radical-reactive or radiation-reactive unsaturated bonds.

The radiation-curable heat-sensitive pressure-sensitive adhesive used in the present invention contains a heat-meltable resin having a melting point of 70 to 200 ° C. as a component. When the melting point is less than 70 ° C., the resulting continuous tape has poor heat resistance, and when the melting point exceeds 200 ° C., the resulting continuous tape has poor adhesive strength development at low temperature heating. A heat-meltable resin that can be preferably used is a rosin-based resin,
Examples include coumarone indene resin, terpene resin, and petroleum resin. The heat fusible resin may be used alone or in combination of two or more.

Specific examples of the rosin resin include rosin ester, hydrogenated rosin ester, disproportionated rosin ester and polymerized rosin ester. Specific examples of the coumarone-indene resin include coumarone-indene resin, hydrogenated coumarone-indene resin, phenol-modified coumarone-indene resin, and epoxy-modified coumarone-indene resin. Specific examples of the terpene-based resin include polyterpene resin, styrene-modified terpene resin, and phenol-modified terpene resin. Specific examples of petroleum-based resins include aliphatic petroleum resins, aromatic petroleum resins,
Examples thereof include aromatic modified aliphatic petroleum resin and aromatic pure monomer resin.

The blending amount of the heat-fusible resin is 50 to 150 parts by weight per 100 parts by weight of the acrylic polymer. If the amount is less than 50 parts by weight, the resulting continuous tape will have poor adhesive strength, and if it exceeds 150 parts by weight, the continuous tape will have poor wettability with respect to the adherend.

The radiation-curable heat-sensitive pressure-sensitive adhesive used in the present invention contains a vinyl group, an acryloyl group,
A polyfunctional monomer having two or more one or more radiation-reactive unsaturated bonds capable of undergoing a crosslinking treatment (curing) upon irradiation with radiation, such as a methacryloyl group and a vinylbenzyl group, is used as a component. Preferred polyfunctional monomers are those having an acryloyl group and / or a methacryloyl group. If the number of the radiation-reactive unsaturated bonds is less than 2, it is difficult to balance the adhesive properties such as the holding force and the adhesive force of the obtained adhesive, and it becomes difficult to form the intended continuous tape. Generally, those containing 10 or less radiation-reactive unsaturated bonds are used, but the number is not limited to this.

Specific examples of the above-mentioned polyfunctional monomers that can be preferably used include diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, and triethylene glycol dimethacrylate. Propylene glycol diacrylate, tripropylene glycol dimethacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, penta Erythritol trimethacrylate, dipe Data hexaacrylate, dipentaerythritol hexa methacrylate, and the like.

The compounding amount of the polyfunctional monomer is 1 to 30 parts by weight per 100 parts by weight of the acrylic polymer. If the blending amount is less than 1 part by weight, the resulting continuous tape will have poor holding force, and if it exceeds 30 parts by weight, the continuous tape will have poor adhesive force.

The radiation-curable heat-sensitive pressure-sensitive adhesive used in the present invention can be prepared by mixing the components. At that time, additives usually used for pressure-sensitive adhesives, for example, fillers such as glass fibers and metal powders, pigments, colorants, plasticizers and the like can be added in usual amounts.

In the tape for connecting electronic parts of the present invention, for example, the radiation-curable heat-sensitive pressure-sensitive adhesive described above is coated on a supporting substrate by an appropriate method, and the adhesive is cured with active energy rays. Can be formed by. When coating the radiation-curable heat-sensitive pressure-sensitive adhesive, it can be diluted with an organic solvent if necessary, but the amount of the organic solvent used is 100 weight% of the radiation-curable heat-sensitive pressure-sensitive adhesive from the viewpoint of solvent-saving coating. It is preferably 20 parts by weight or less per part. In the present invention, sufficient coatability is exhibited by using such an amount of the organic solvent.

As the supporting base material, suitable materials such as paper base materials such as crepe paper and kraft paper, plastic films or sheets, cloth, metal foil, etc. may be used. The thickness of the pressure-sensitive adhesive layer provided on the supporting substrate is generally 30 to 200 μm, but the thickness is not limited to this and may be an appropriate thickness.

Examples of active energy rays for curing the pressure-sensitive adhesive layer on the supporting substrate include α rays, β rays,
Examples include ionizing radiation such as gamma rays, neutron rays, and electron rays, and ultraviolet rays. In the case of ionizing radiation, the irradiation dose is usually about 0.5 to 20 Mrad, preferably 1 to 10 Mrad. In the case of ultraviolet rays, it is usually 400 to 3000 mj /
It is about cm ² .

The ultraviolet ray is preferably in the wavelength range of 180 to 460 nm, and a mercury lamp or a metal halide lamp is preferable as a source of the ultraviolet ray. Further, when curing by ultraviolet irradiation, it is desirable to add a photoreaction initiator (photosensitizer) to the pressure-sensitive adhesive. Examples of the photoreaction initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, dibenzyl, benzyl dimethyl ketal and the like.

Application of the tape for connecting electronic parts of the present invention is as follows.
Although not limited, for example, it can be performed as follows. In other words, the end portions of the lead wires of the electronic parts are temporarily fixed to the pressure-sensitive adhesive layer of the tape for continuous installation, and the individual electronic parts are arranged in series at equal intervals so as to be in a staggered arrangement. After that, for example, a basis weight of 100 to 3
A tape-like base material having a self-supporting property such as kraft paper or cardboard of 00 g / m ² is attached to the pressure-sensitive adhesive layer via a lead wire, and heat-treated at 40 to 80 ° C. for 0.1 to 1 second. It can be done by

As described above, the individual electronic components suitable for the automatic assembling system for automatically supplying the electronic components to the manufacturing process of the circuit board and the like are firmly arranged by the continuous tapes arranged in a sloping shape. What is adhered and held is formed.

In the above-mentioned tape for connecting electronic parts of the present invention, a tape for connecting parts having a width of 10 mm is used and the diameter is 0.5 mm.
The lead wire of No. 1 was bonded and held under a thermocompression bonding condition of 60 ° C. × 3 kg / cm ² × 1.0 seconds through kraft paper having a basis weight of 200 g / m ² (width 10 mm).
It is preferable that the lead wire is formed so that the positional deviation of the lead wire is 0.5 mm / hour or less when a pulling load of 00 g is applied and the atmosphere is at 40 ° C. With tapes for connecting electronic components with a displacement of more than 0.5 mm / hour, the electronic components arranged in a staggered pattern may be displaced or dropped during storage, and an automatic electronic component installation system controlled by a computer is available. This is likely to cause harmful effects such as malfunctions.

[0027]

EFFECTS OF THE INVENTION According to the present invention, a pressure-sensitive adhesive layer can be formed without solvent or with a small amount of solvent used, and the formed pressure-sensitive adhesive layer is cured by radiation and weakly adheres before heat treatment. The electronic component can be easily temporarily fixed through the lead wire by showing the force, and the electronic component can be firmly adhered and held by the heat treatment for a short time at a low temperature of 100 ° C. or less. Therefore, it is possible to obtain a tape for connecting electronic components, which is excellent in maintainability of the staggered arrangement of electronic components, or in maintaining the fixed position of the electronic components, while using a solvent.

[0028]

【Example】

Reference Example 1 In a reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirrer, 80 parts of butyl acrylate (weight part, the same applies hereinafter),
17 parts ethyl acrylate, 3 parts acrylamide, 0.2 parts 2-hydroxyethyl acrylate, 0.15 parts 2-mercaptoethanol, 0.15 parts 2,2'-azobis-2-cyanopropanol, 50 parts ethyl acetate Was added and polymerized in a nitrogen stream to obtain an acrylic polymer having a weight average molecular weight of 200,000.

Reference Example 2 70 parts of isononyl acrylate, 15 parts of isobutyl acrylate, 10 parts of vinyl acetate, 5 parts of acrylic acid were placed in a reaction vessel equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer and a stirrer.
0.2 parts of 2'-azobisisobutyronitrile, 0.1 part of lauryl mercaptan and 50 parts of toluene were added, and the mixture was polymerized in a nitrogen stream to obtain an acrylic polymer having a weight average molecular weight of 240,000.

Reference Example 3 The acrylic polymer obtained in Reference Example 1 was reacted with 0.7 part of 2-methacryloyloxyethyl isocyanate in the presence of 0.1 part of dibutyltin dilaurate to give an acrylic polymer having a methacryloyl group. Got united.

Example 1 100 parts of the acrylic polymer obtained in Reference Example 1, 40 parts of phenol-modified terpene resin (melting point 130 ° C.), pentaerythritol ester of polymerized rosin (melting point 120 ° C.) 30
Parts and trimethylolpropane trimethacrylate 1
A radiation-curable heat-sensitive pressure-sensitive adhesive was prepared by mixing 0 parts. Then, the above radiation-curable heat-sensitive pressure-sensitive adhesive was applied onto a crepe paper having a basis weight of 80 g / m ² , dried at 120 ° C. for 3 minutes, and then irradiated with an electron beam at an acceleration voltage of 165 kV for 3 Mrad for curing treatment. Then, a tape for connecting electronic components having a pressure-sensitive adhesive layer having a thickness of about 40 μm was obtained.

Example 2 100 parts of the acrylic polymer obtained in Reference Example 1, pentaerythritol ester of hydrogenated rosin (melting point 100 ° C.) 80
Part, hydrogenated coumarone indene resin (melting point 100 ° C.) 30
Parts and trimethylolpropane trimethacrylate 1
0 parts were mixed to prepare a radiation-curable heat-sensitive pressure-sensitive adhesive,
Using this, a tape for connecting electronic components was obtained according to Example 1.

Example 3 100 parts of the acrylic polymer obtained in Reference Example 2, pentaerythritol ester of polymerized rosin (melting point 120 ° C.) 50
Parts, aromatic modified aliphatic petroleum resin (melting point 90 ° C) 25
Part, 5 parts of trimethylolpropane triacrylate, and 5 parts of tetraethylene glycol dimethacrylate were mixed to prepare a radiation-curable heat-sensitive pressure-sensitive adhesive, and the tape was used according to Example 1 for connecting electronic components. Got

Example 4 100 parts of the acrylic polymer obtained in Reference Example 3, 40 parts of phenol-modified terpene resin (melting point 130 ° C.), pentaerythritol ester of polymerized rosin (melting point 120 ° C.) 30
Parts and trimethylolpropane trimethacrylate 5
A radiation-curable heat-sensitive pressure-sensitive adhesive was prepared by mixing the parts, and using this, a tape for connecting electronic components was obtained according to Example 1.

Comparative Example 1 70 parts of hydrogenated rosin triethylene glycol ester (melting point -18 ° C.) and hydrogenated coumarone indene resin (melting point 100 ° C.) 30 were used in place of the phenol-modified terpene resin and the polymerized rosin pentaerythritol ester. A radiation curable composition and a tape for connecting electronic components were obtained in the same manner as in Example 1 except that the parts were used.

Comparative Example 2 The amount of the phenol-modified terpene resin used was 20 parts, and the amount of the pentaerythritol ester of the polymerized rosin used was 1 part.
A radiation curable composition and a tape for connecting electronic components were obtained in the same manner as in Example 1 except that the content was changed to 0 part.

Evaluation test Adhesive force (pull-out force) Tape for connecting electronic parts obtained in Examples and Comparative Examples (width: 10 m)
m) The pressure-sensitive adhesive layer or the composition layer is temporarily fixed in parallel to the U-shaped bent lead wire having a diameter of 0.5 mm in the electronic component at the end portion having a length of 10 mm at an interval of 5 mm. After that, through the lead wire, the basis weight is 200 g /
² pieces of m ² kraft paper tape (width 10 mm)
Force required for lead wire pull-out (speed 300 mm / min) for the test pieces obtained by pressure bonding for 1.0 second (heating) under the conditions of 3 ° C (room temperature), 60 ° C or 100 ° C, 3 kg / cm ² I checked.

Retention property According to the above, a test piece heat-pressed under the conditions of 60 ° C. and 3 kg / cm ² for 1.0 second was applied to the bent portion of the lead wire.
Apply a load of 00g, 200g, or 400g, and arrange the load so that it will pull out the lead wire.
The sample was left at the temperature of 120 minutes for 120 minutes to examine the amount of deviation.

The above results are shown in Table 1.

[Table 1]

From Table 1, the tape for connecting electronic parts of the present invention shows a weak drawing force before the heat treatment, and an excellent drawing force is developed in a short time heat treatment, so that the electronic parts are firmly adhered and held. It can be seen that even in the loaded state, the fixed position retention property is excellent.

Front page continuation (72) Inventor Katsuhiko Kamiya 1-2-2 Shimohozumi, Ibaraki City, Osaka Prefecture Nitto Denko Corporation (72) Inventor Shoichi Tanimoto 1-2 1-2 Shimohozumi, Ibaraki City, Osaka Nitto Denko Corporation Within the corporation

Claims (1)

[Claims] 1. A tape for arranging and holding electronic components in a sloping manner through lead wires of a pressure-sensitive adhesive layer provided on a supporting substrate, wherein the pressure-sensitive adhesive layer has the general formula: C
^{_{H 2 = C (R 1)}} COOR 2 ( provided that, R ¹ is hydrogen or methyl, R ² is an alkyl group having a carbon number of 2 to 14.)
100 parts by weight of an acrylic polymer containing 50% by weight or more of an acrylic monomer unit represented by
50 to 150 parts by weight of a heat-meltable resin at 200 ° C. and a radiation-curable heat-sensitive pressure-sensitive adhesive containing 1 to 30 parts by weight of a polyfunctional monomer having two or more radiation-reactive unsaturated bonds in the molecule. A tape for connecting electronic components, characterized in that