JP2002167559A - Damming material and method for manufacturing sealed electronic part using this damming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damming material for retaining a flowable substance having curability in a specified space until curing which is constituted of a pressure-sensitive adhesive sheet and can firmly hold the flowable substance without leakage when the flowable. substance has fluidity, and simultaneously, is readily peelable after curing without damaging the adherend. SOLUTION: The damming material retains a flowable substance having curability in a specified space until curing, and is constituted of a heat peelable pressure-sensitive adhesive sheet having a thermally expansible pressure-sensitive adhesive layer containing thermally expansible fine spheres on at least one side of a base material. A cured product can be produced by introducing the flowable substance having curability into this specified space enclosed with this damming material then curing the above flowable substance having curability by a curing means, subsequently expanding the thermally expansible pressure- sensitive adhesive layer of the damming material by heating, and peeling the damming material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dam member which is composed of a heat-peelable pressure-sensitive adhesive sheet and which holds a fluid material having curability in a predetermined space until it is cured, and a cured material using the dam material. And a method of manufacturing a sealed electronic component.

[0002]

2. Description of the Related Art Conventionally, it has been known to use a pressure-sensitive adhesive sheet as a dam member for retaining a fluid material having curability in a predetermined space until it is cured when producing a cured product. Using this pressure-sensitive adhesive sheet, create a space in which the flowable substance having curability does not leak, then inject the flowable substance having curability, cure the substance by a curing means such as heat or ultraviolet light, and remove unnecessary substances. By peeling off the adhesive sheet, a cured product having a desired shape can be obtained. As an example of such a dam application, there is a curing step of a sealing resin in a manufacturing process of an electronic component.

However, in the conventional manufacturing method using a pressure-sensitive adhesive sheet, when a fluid material having curability is cured, an adherend (surrounding portion or a cured product) adheres firmly to the pressure-sensitive adhesive sheet. It may be difficult to peel off the pressure-sensitive adhesive sheet, or the adherend may be destroyed when peeling off.

[0004] In the manufacturing process of a sealed electronic component in which the electronic component is sealed with a resin, there is a high demand to avoid light stress as the component is miniaturized. The stress at the time of peeling from the part becomes large, causing a problem of damage to parts. Therefore, the adhesive tape used in the manufacturing process of sealed electronic components has a small stress when peeling, but does not leak liquid until the fluid substance having curability is cured, and adheres firmly. There are conflicting demands that they have to be.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a weir comprising an adhesive sheet for retaining a curable fluid substance in a predetermined space until it is cured. When it has fluidity, it does not peel off from the surrounding attached parts, can be held firmly without leaking liquid, and after curing, it hardens and the surrounding attached parts (hereinafter simply referred to as " A stress which is small when the pressure-sensitive adhesive sheet is peeled off from the "adherend", and which can be easily peeled without damaging the adherend, and a cured product using the dam. An object of the present invention is to provide a manufacturing method and a method for manufacturing a sealed electronic component.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that an adhesive sheet having a heat-expandable adhesive layer containing heat-expandable microspheres is used as a dam material (dam material; dam). When used as a member for applications), it has been found that a cured product can be produced smoothly and that a sealed electronic component can be produced without damage, and the present invention has been completed.

[0007] That is, the present invention relates to a dam member for retaining a curable fluid substance in a predetermined space until it is cured, wherein at least one of the base materials contains heat-expandable microspheres. The present invention provides a dam member composed of a heat-peelable pressure-sensitive adhesive sheet having a heat-expandable pressure-sensitive adhesive layer. The present invention also provides a method in which, after injecting a curable fluid substance into a predetermined space partitioned by the dam member, the curable fluid substance is cured by a curing unit, and then the dam member is cured. A method for producing a cured product, characterized in that a heat-expandable pressure-sensitive adhesive layer is expanded by heating to peel off a weir member to obtain a cured product.

[0008] The present invention also provides a method in which a curable fluid material is injected into a predetermined space partitioned by the dam member and in which electronic components are arranged, and then the curable fluid is injected by a curing means. A method for producing an electronic component sealed with a cured product by curing an adhesive substance and then expanding the heat-expandable pressure-sensitive adhesive layer of the damper by heating to peel off the damper. I will provide a.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described in detail with reference to the drawings as necessary. FIG. 1 is a schematic cross-sectional view showing an example of a dam member (heat-peelable pressure-sensitive adhesive sheet) of the present invention. A heat-expandable pressure-sensitive adhesive layer is provided on one surface of a support substrate 1 via a rubber-like organic elastic layer 2. 3 are provided, and a separator 4 is further laminated thereon. The rubbery organic elastic layer 2 and the heat-expandable adhesive layer 3
And a pressure-sensitive adhesive sheet having a normal pressure-sensitive adhesive layer on the other surface.

The support base material 1 is a support base material for the dam member. Generally, a plastic film or sheet is used. For example, paper, cloth, nonwoven fabric, metal foil, a plastic laminate thereof, An appropriate thin leaf such as a laminate can be used. The thickness of the supporting substrate 1 is generally 500 μm or less, preferably 1 to 300 μm.
m, more preferably about 5 to 250 μm, but is not limited thereto.

The rubber-like organic elastic layer 2 has a function of providing a large bonding area by adhering the surface of the adherend to the surface of the adherend when the damper is adhered to the adherend. The heat-expandable pressure-sensitive adhesive layer 3 is heated and foamed and / or peeled off from the adherend.
Or, when expanding, foaming and / or
Alternatively, the expansion of the heat-expandable pressure-sensitive adhesive layer 3 is reduced by three-dimensionally changing the structure so as to promote the formation of an undulating structure.

The rubbery organic elastic layer 2 is made of ASTM D-2.
It can be formed of natural rubber or synthetic rubber having a D-type shear D-type hardness of 50 or less, preferably 40 or less, or a synthetic resin having rubber elasticity.

Examples of the synthetic rubber or synthetic resin include nitrile, diene, and acrylic synthetic rubbers; polyolefin and polyester thermoplastic elastomers; ethylene-vinyl acetate copolymer, polyurethane and polybutadiene. , Such as soft polyvinyl chloride,
Synthetic resins having rubber elasticity are exemplified. In the present invention, even a rigid polymer such as polyvinyl chloride, which has rubber elasticity in combination with a compounding agent such as a plasticizer or a softener, can be used in the present invention.

Further, it can be formed of a generally known pressure-sensitive adhesive such as rubber or resin. As pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives,
An appropriate material such as a styrene-conjugated diene block copolymer pressure-sensitive adhesive can be used. Further, a pressure-sensitive adhesive having improved creep characteristics by blending a heat-meltable resin having a melting point of about 200 ° C. or less can also be used. The pressure-sensitive adhesive may contain appropriate additives such as a crosslinking agent, a tackifier, a plasticizer, a filler, an antioxidant, and the like.

More specifically, examples of the pressure-sensitive adhesive include a rubber-based pressure-sensitive adhesive using a natural rubber or a synthetic rubber as a base polymer; a methyl group, an ethyl group, a propyl group, a butyl group, a 2-ethylhexyl group; Isooctyl group, isononyl group, isodecyl group, dodecyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group,
Acrylic acid-based alkyl esters such as acrylic acid or methacrylic acid having an alkyl group having 20 or less carbon atoms, such as acrylic acid, methacrylic acid, icotanic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate,
Hydroxypropyl acrylate, hydroxypropyl methacrylate, N-methylolacrylamide, acrylonitrile, methacrylonitrile, glycidyl acrylate, glycidyl methacrylate, vinyl acetate, styrene,
Acrylic pressure-sensitive adhesives containing an acrylic polymer having isoprene, butadiene, isobutylene, vinyl ether or the like as a main component as a base polymer may be used.

The heat-expandable pressure-sensitive adhesive layer 3 contains at least a pressure-sensitive adhesive for imparting adhesiveness and heat-expandable microspheres (microcapsules) for imparting thermal expansivity.
Therefore, after the fluid material having curability is cured, the heat-expandable pressure-sensitive adhesive layer 3 is heated to expand and / or expand the heat-expandable microspheres so that the heat-expandable pressure-sensitive adhesive layer 3 adheres to the heat-expandable pressure-sensitive adhesive layer 3. The pressure-sensitive adhesive sheet can be easily peeled off by reducing the bonding area with the body. It should be noted that a foaming agent that is not microencapsulated cannot stably exhibit good releasability.

The heat-expandable microspheres may be microspheres in which a substance that easily gasifies and expands by heating, such as isobutane, propane, and pentane, is contained in an elastic shell. The shell is often formed of a heat-meltable substance or a substance that breaks due to thermal expansion. Examples of the material forming the shell include a vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, and polysulfone. The heat-expandable microspheres can be produced by a conventional method, for example, a coacervation method, an interfacial polymerization method, or the like. In addition, there is a commercially available product such as Matsumoto Microsphere (trade name, manufactured by Matsumoto Yushi Seiyaku Co., Ltd.) as the thermally expandable microsphere.

In order to efficiently reduce the adhesive force of the heat-expandable pressure-sensitive adhesive layer by heat treatment, heat-expandable microspheres having an appropriate strength that does not burst until the volume expansion rate becomes 5 times or more, especially 10 times or more are preferable. .

The blending amount of the heat-expandable microspheres can be appropriately set according to the expansion ratio of the pressure-sensitive adhesive layer and the property of lowering the adhesive strength.
Generally, the base polymer 1 forming the heat-expandable adhesive layer 3
For example, 1 to 150 parts by weight, preferably 10 to 130 parts by weight, and more preferably 25 to 10 parts by weight with respect to 00 parts by weight.
0 parts by weight.

The pressure-sensitive adhesive forming the heat-expandable pressure-sensitive adhesive layer 3 is a conventional or known pressure-sensitive adhesive based on a rubber-based material or resin that permits the expansion and / or expansion of the heat-expandable microspheres when heated. And / or foaming of the agent, preferably the heat-expandable microspheres.
Alternatively, a material that does not restrict expansion as much as possible is used. Examples of such a pressure-sensitive adhesive include the pressure-sensitive adhesives exemplified in the rubber-like organic elastic layer. The heat-expandable pressure-sensitive adhesive layer preferably has a pressure-sensitive adhesive which has a characteristic of firmly adhering to the adherend before heating but having a reduced adhesive strength after heat treatment. Specifically, the dynamic elastic modulus is 5,000 to 10 at normal temperature to 150 ° C.
It is a pressure-sensitive adhesive based on a polymer in the range of 10,000 Pa.

Thermally expandable adhesive layer 3 and rubbery organic elastic layer 2
Each has a thickness of 5 to 300 μm, preferably 20 to 300 μm.
150 μm is used. However, the thickness of the heat-expandable pressure-sensitive adhesive layer 3 is preferably larger than the maximum particle size of the heat-expandable microspheres contained therein. If the thickness is small, the surface smoothness is impaired due to the unevenness of the heat-expandable microspheres, and the adhesive strength before heating is reduced. Also,
If it is thicker than necessary, cohesive failure may occur after foaming of the heat-expandable pressure-sensitive adhesive layer 3, and adhesive residue may be left on the adherend. When the thickness of the rubber-like organic elastic layer 2 is small, the three-dimensional structure cannot be changed after heating and foaming, and the releasability deteriorates.

In the present invention, as the separator 4, a conventional release paper or the like can be used. The separator 4 is used as a protective material for the heat-expandable pressure-sensitive adhesive layer 3 and is peeled off when the pressure-sensitive adhesive sheet is adhered to the adherend. The separator 4 does not necessarily have to be provided.

The fluid material having curability serves as, for example, a sealing resin in a manufacturing process of a sealing electronic component.
Specifically, thermosetting resins such as thermosetting silicone resins and thermosetting epoxy resins, UV curable resins such as UV curable silicone resins, moisture curable resins, anionic curable resins, cation curable resins, etc. , But is not limited thereto.

Next, a method for producing a cured product will be described step by step. First, a space for retaining a fluid material having curability is created by using the dam material of the present invention. This space may be partitioned only by the weir member, or may be formed by a member and a weir member that are finally integrated with the cured product.
For example, the space can be formed by closing one or both sides of the opening of the tubular member that is finally integrated with the cured product with a dam. In the case where both sides of the opening of the tubular member are closed with the dam material, an inlet for a fluid substance having curability is provided. Next, a fluid material having curability is injected into the space partitioned by the weir material. The injection can be performed by a conventional method for injecting a fluid substance, for example, a flow-down method, a supply method using a pump, or the like. Thereafter, the fluid substance having curability is cured by a curing means such as heat or radiation, and unnecessary dams are peeled off by heating to obtain a desired cured product.

The heat treatment conditions for allowing the barrier material of the present invention to be easily peeled off from the adherend include the following: the surface condition of the adherend, the type of the heat-expandable microspheres, etc.
It can be set as appropriate depending on conditions such as the heat resistance of the substrate and the adherend and the heating method. General heat treatment conditions are temperature 90-250.
At 10 ° C for 10 to 300 seconds (hot plate etc.) or 1
~ 30 minutes (hot air dryer etc.). Under the above heating conditions,
Usually, the heat-expandable microspheres of the pressure-sensitive adhesive layer expand and / or foam, and the pressure-sensitive adhesive layer expands and deforms, and the adhesive strength is reduced or lost.
Note that the heat treatment can be performed at an appropriate stage depending on the purpose of use. In some cases, an infrared lamp or heated water can be used as a heating source. The weir material may be, for example, Riva Alpha [trade name, Nitto Denko Corporation]
Heat-peelable pressure-sensitive adhesive sheets, such as those manufactured by Nippon Electric Co., Ltd.) and Riverclean [trade name, manufactured by Nitto Denko Corporation].

According to the method for producing a cured product, since the heat-peelable pressure-sensitive adhesive sheet having the heat-expandable pressure-sensitive adhesive layer containing the heat-expandable microspheres is used as the dam member, the flowable material having curability flows. When there is a property, it can be held firmly without leaking liquid, and after curing, the heat-expandable adhesive layer of the weir expands by heating, and it can be easily peeled, and the stress at the time of peeling Can be reduced, so that damage to the adherend can be prevented or suppressed.

The method for producing a sealed electronic component according to the present invention is an application example of the above-mentioned method for producing a cured product. In the manufacturing method of the sealed electronic component of the present invention, first, a fluid material having curability is injected into a predetermined space partitioned by the dam member of the present invention and in which the electronic component is arranged. The electronic components are not particularly limited, and for example, semiconductors, circuits, various printed boards, various masks, lead frames, and the like can be used.
The space may be partitioned only by the dam material, or may be formed by a part of the electronic component (for example, a substrate) and the dam material. The injection of the fluid material having curability, the subsequent curing of the fluid material, and the peeling of the dam member by heating can be performed in the same manner as described above. In the sealed electronic component thus obtained, the whole or a part of the electronic component is sealed with the cured product.

According to the method for producing a sealed electronic component of the present invention, since the above-mentioned heat-peelable pressure-sensitive adhesive sheet is used as a dam, when the curable fluid substance has fluidity, it can be securely leaked without liquid. By keeping the heat-expandable pressure-sensitive adhesive layer expanded by heating and peeling the damping material from the adherend, the stress at the time of peeling can be kept small, and the sealed electronic component can be manufactured without damaging the electronic component. Can be.

[0029]

According to the present invention, a pressure-sensitive adhesive sheet having a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres is used as a damping material for a curable flowable substance in the production of a sealed electronic component. As a result, it is possible to hold firmly without leaking liquid until the hardening and flowing substance is hardened, and after hardening, the adhesiveness of the adhesive layer can be significantly reduced by simple means of heating. When the pressure-sensitive adhesive sheet is peeled from the body, the pressure-sensitive adhesive sheet has a small stress and can be easily peeled without damaging the cured product or the surrounding adherend. for that reason,
The cured product can be manufactured smoothly, and the sealed electronic component can be manufactured without damage.

[0030]

Example 1 Ethyl acrylate-2-ethylhexyl acrylate-acrylic acid (50 parts by weight to 50 parts by weight to 5 parts by weight) copolymer isocyanate-based crosslinking agent based on 100 parts by weight of a pressure-sensitive adhesive. 3 parts by weight, rosin-based tackifying resin 2.5 parts by weight,
Thermal expansion microspheres (trade name "Matsumoto Microsphere F"
-50D "(manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) in a 50 μm-thick polyester film (trade name“ Lumirror S10 ”, manufactured by Toray Industries, Inc.) so that the thickness after drying becomes 35 μm. )) To produce a dam material. Drill a hole of 1cm ^{2 in} a copper foil of 100μm thickness,
The dam material is attached to one side of the hole so as to cover one of the holes, and a thermosetting one-component silicone resin is dripped on the other surface of the hole so as to cover all the holes, and heated at 80 ° C. for 5 hours in an atmosphere. After curing, a sample was prepared.

Comparative Example 1 From the example, a sample was prepared using a pressure-sensitive adhesive sheet from which heat-expandable microspheres had been removed as a dam member. Evaluation Test The prepared sample was heated and cooled in an atmosphere of 130 ° C. for 5 minutes, after which the resin entered the interface between the dam and the copper foil, the maximum load when the dam (adhesive sheet having a width of 20 mm) was peeled off, and The presence or absence of deformation of the copper foil after peeling was visually checked. These results are shown in Table 1.

[Table 1]

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a weir member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Support base material 2 Rubbery organic elastic layer 3 Thermal expansion adhesive layer 4 Separator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Murata Akiri 1-2-1, Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Kazuyuki Kiuchi 1-1-1, Shimohozumi, Ibaraki-shi, Osaka No. 2 Nitto Denko Corporation F term (reference) 4J004 AA05 AA07 AA10 AB01 CA01 CA02 CA08 CB01 CB02 CC02 CC03 CD04 FA10 5F061 AA01 CA01 CB13 DE03

Claims (3)

[Claims] 1. A weir member for retaining a curable fluid substance in a predetermined space until it is cured,
A dam member comprising a heat-peelable pressure-sensitive adhesive sheet having a heat-expandable pressure-sensitive adhesive layer containing heat-expandable microspheres on at least one of the substrates. 2. After a fluid material having curability is injected into a predetermined space partitioned by the dam member according to claim 1,
A method for producing a cured product, comprising: curing the fluid substance having curability by a curing means, and then expanding the heat-expandable pressure-sensitive adhesive layer of the weir by heating to release the weir, thereby obtaining a cured product. . 3. A fluid material having curability is injected into a predetermined space partitioned by the dam member according to claim 1 and in which electronic components are arranged, and then the fluidity having curability is injected by curing means. A method for manufacturing a sealed electronic component, comprising: curing a substance; and then expanding the heat-expandable pressure-sensitive adhesive layer of the dam by heating to release the dam, thereby obtaining an electronic component sealed with a cured product.