KR20210011744A - Functional adhesive tape for SMT - Google Patents

Abstract

Disclosed is a functional adhesive tape for SMT, which can minimize wrinkling by providing elasticity, and having electrical conductivity and thermal conductivity to quickly remove heat and electromagnetic waves generated from a heating element.

Description

Functional adhesive tape for SMT {Functional adhesive tape for SMT}

The present invention relates to a functional adhesive tape for surface mounting, and in particular, relates to a functional adhesive tape for surface mounting that has elasticity, has electrical and thermal conductivity, and can quickly remove heat and electromagnetic waves generated from a heating element. .

Functional adhesive tapes have thermal conductivity or electrical conductivity in the thickness direction, and are used to thermally or electrically connect opposite objects, or to shield electromagnetic waves in the case of electrical conductivity.

As such a functional adhesive tape, for example, as in Japanese Patent Application Laid-Open No. 11-302615, a conductive adhesive tape composed of a metal foil and an adhesive layer (pressure sensitive adhesive layer) provided on one side of the metal foil, or Japanese Patent Application Publication No. 2005 As in No. 277145, a conductive adhesive tape in which an adhesive layer in which a conductive filler such as nickel powder is dispersed is installed on a metal foil is known.

This adhesive tape has a disadvantage in that it is easy to be wrinkled by a metal foil and the range that can be pressed in the up and down directions is very limited, and it is difficult to use it as an electrically conductive gasket or thermally conductive gasket having elasticity in the up and down directions alone.

In addition, according to Korean Patent Registration No. 10-0920766, a conductive fabric layer is formed by plating, coating, or impregnating a conductive metal on a fiber fabric or mesh of a woven or nonwoven fabric, and conductive powder, a binder resin, and a solvent are applied thereon. It discloses forming a conductive elastic layer by coating and then curing the containing composition.

These adhesive tapes are less wrinkled, but are difficult to use in places where electrical insulation is required on the top surface, and have a disadvantage in that it is difficult to transfer heat from the heating area to other places in a vertical direction due to low thermal conductivity. In addition, there is a disadvantage in that it is difficult to use an electrically conductive gasket or a thermally conductive gasket having elasticity in the up and down directions because the range that can be pressed in the up and down directions is very limited.

Accordingly, it is an object of the present invention to provide a functional adhesive tape for surface mounting that has elasticity and flexibility, so that it is less wrinkled and is easily compressed after being interposed between objects and has thermal conductivity and electrical conductivity.

Another object of the present invention is to provide a functional adhesive tape for surface mounting having a structure and material that transmits heat well in the upper direction and shields electromagnetic waves in the horizontal direction.

Another object of the present invention is to provide a functional adhesive tape capable of surface mounting by vacuum pickup.

The above object is a polymer fiber sheet having an irregular size penetrating in the thickness direction, having a plurality of irregularly arranged gaps, and plated with a metal layer; A pressure-sensitive adhesive layer that is adhered to the lower surface of the fiber sheet and has electrical and thermal conductivity properties, and has self-adhesive strength on both the upper and lower surfaces; And an elastic body adhered to the upper surface of the fiber sheet and having electrical insulation and heat conduction properties, wherein the elastic body is at least twice the combined thickness of the fiber sheet and the adhesive layer, and penetrates through a gap of the fiber sheet. It is achieved by a functional adhesive tape for surface mounting, characterized in that the pressure-sensitive adhesive layer and the elastic body are in direct contact and thermally connected by a pressure-sensitive adhesive layer portion, an elastic body portion or both.

Preferably, the point at which the pressure-sensitive adhesive layer and the elastic body directly contact may be an interior of the fiber sheet or a boundary where the pressure-sensitive adhesive layer or the elastic body and the fiber sheet meet.

Preferably, at least one of the pressure-sensitive adhesive layer and the liquid polymer corresponding to each of the elastic body penetrates through the gap of the fiber sheet and is cured to contact each other.

Preferably, in the elastic body, a surface in contact with the fiber sheet may have a self-adhesive force, and a surface exposed to the outside may have self-adhesion or no self-adhesion to facilitate vacuum pickup.

Preferably, a release film or a release paper may be attached to the lower surface of the pressure-sensitive adhesive layer exposed to the outside.

Preferably, the thickness of the elastic body may be about three times the thickness of the fiber sheet.

Preferably, the metal layer is formed by plating with a copper layer, and the thickness of the copper layer may be thicker than 1/4 of the thickness of the fiber sheet.

Preferably, a copper foil having a plurality of fine holes formed therebetween may be interposed between the fiber sheet and the elastic body, and the fiber sheet and the copper foil may be bonded to each other by adhesion between the elastic body and the fiber sheet.

Preferably, a thermally conductive elastic member may be adhered to at least a part of the lower surface of the pressure-sensitive adhesive layer by the adhesive force of the pressure-sensitive adhesive layer.

According to the present invention, it is possible to minimize the wrinkles of the functional adhesive tape by providing elasticity and flexibility by the elastic body having a certain thickness or more, and is easily compressed after being interposed between opposite objects.

In addition, since it is equipped with a material having good thermal conductivity and electrical conductivity, it easily transfers heat to the upper direction and shields electromagnetic waves in the horizontal direction, so that the electromagnetic waves generated from the heating element quickly transfer the heat generated from the heating element to the upper direction. It is easy to shield in the horizontal direction.

In addition, the upper surface exposed to the outside has a surface for easy vacuum pickup and is roll-taped by the mechanical strength of an elastic body having a certain thickness or more, so that surface mounting by vacuum pickup is easy.

1 is a cross-sectional view showing a functional adhesive tape according to the present invention.
2 is a cross-sectional view showing a state of use of a functional adhesive tape.

It should be noted that the technical terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present invention should be interpreted as generally understood by those of ordinary skill in the technical field to which the present invention belongs, unless otherwise defined in the present invention, and is excessively comprehensive. It should not be construed as a human meaning or an excessively reduced meaning.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a functional adhesive tape 100 according to the present invention.

The functional adhesive tape 100 is made of a laminate formed by attaching the adhesive layer 120 to the lower surface of the polymer fiber sheet 110 on which the metal layer is formed, and the elastic body 130 to the upper surface.

The functional adhesive tape 100 has a thickness of about 0.18 mm to 0.45 mm, and the functional adhesive tape 100, which is supplied through a reel and converted, is vacuum picked up from the surface to obtain an object, such as a shield can. The pressure-sensitive adhesive layer 120 may be adhered to the upper surface of ).

Referring to the enlarged circle of FIG. 1, the fiber sheet 110 is a nonwoven sheet made of a polymer in which a metal layer 111 is formed, and has an irregular size penetrating in the thickness direction of the laminate, and a plurality of irregularly arranged gaps 112 It is equipped with.

The thickness of the fiber sheet 110 is about 10 microns to 40 microns, and the thickness of the metal layer 111 is about 2 microns to 7 microns so that the thermal conductivity in the thickness direction of the functional adhesive tape 100 is good. It may be thicker than 1/4, but is not limited thereto.

In addition, it is preferable that the plurality of gaps 112 of the nonwoven sheet made of a polymer are formed widely and evenly as much as possible so that the elastic body 130 having good thermal conductivity can penetrate a lot. For example, the total surface area of the gap relative to the total surface area of the nonwoven sheet may be 25% or more.

The metal layer 111 is preferably a thick copper layer so as to have good thermal conductivity in the thickness direction, but a thin nickel layer may be formed on the copper layer to prevent oxidation of the copper layer.

The pressure-sensitive adhesive layer 120 has electrical and thermal conductivity properties, and both upper and lower surfaces have self-adhesion. For example, the upper surface of the pressure-sensitive adhesive layer 120 is self-adhesive to the fiber sheet 110 by the self-adhesive force of the upper surface.

The pressure-sensitive adhesive layer 120 has a thin thickness of approximately 5 microns to 20 microns so that the adhesive tape 100 has good thermal conductivity, and has an electrical resistance in the thickness direction of 1 ohm or less.

The pressure-sensitive adhesive layer 120 may be provided by mixing an acrylic resin or a silicone rubber resin with a metal powder, and the type of the polymer resin may be determined as a material that adheres well to the material of the object in contact with it from the outside.

The elastic body 130 has electrical insulation and heat conduction properties, and the surface in contact with the fiber sheet 110 has self-adhesive power, and the surface exposed to the outside has a self-adhesive strength or self-adhesive power enough to facilitate vacuum pickup. It may be absent, and the elastic body 1300 at the portion in contact with the fiber sheet 110 is self-adhesive with the self-adhesive force of the elastic body 130.

The elastic body 130 is provided by an electrically insulating thermally conductive silicone rubber that is cured after mixing a liquid silicone rubber with thermally conductive ceramic powder. The thickness of the elastic body 130 is at least twice the combined thickness of the fiber sheet 110 and the pressure-sensitive adhesive layer 120 in order to improve the mechanical strength, preferably at least three times the thickness of the fiber sheet 110, and the compression range It is desirable to increase the value.

Preferably, the hardness of the elastic body 130 is 40 to 75 Shore A and the thermal conductivity is 2W/m.K or more.

Optionally, a release film or release paper may be attached to the lower surface of the pressure-sensitive adhesive layer 120 exposed to the outside.

According to the present invention, the pressure-sensitive adhesive layer 120 and the elastic body 130 are in direct contact with each other and are thermally connected by a pressure-sensitive adhesive layer portion, an elastic body portion, or both penetrating through the plurality of gaps 112 of the fiber sheet 110.

Here, the point at which the pressure-sensitive adhesive layer 120 and the elastic body 130 directly contact may be an inside of the fiber sheet 110 or a boundary where the pressure-sensitive adhesive layer 120 or the elastic body 130 and the fiber sheet 110 meet. .

As described later, the liquid polymer constituting the pressure-sensitive adhesive layer 120 or the elastic body 130 penetrates and contacts the fiber sheet 110. For example, if one does not penetrate into the fiber sheet 110, the other It can penetrate to the boundary and make contact.

Preferably, in consideration of the efficiency or thermal conductivity of the manufacturing process, the liquid polymer constituting the elastic body 130 penetrates into the fiber sheet 110 and contacts the pressure-sensitive adhesive layer 120.

In this way, since the pressure-sensitive adhesive layer 120 having thermal conductivity and the elastic body 130 are in direct contact and are thermally connected, heat generated from the heating element can be quickly transferred upward.

In another embodiment, a copper foil having a plurality of fine holes may be interposed between the fiber sheet 110 and the elastic body 130.

According to this structure, the mechanical strength is increased by the copper foil, vacuum pickup is easy, and the heat conduction and electromagnetic wave shielding are improved by the copper foil.

The fiber sheet 110, the copper foil, the elastic body 130, and the copper foil, for example, may be bonded to each other by an adhesion process of the elastic body 130 and the fiber sheet 110. For example, when a liquid thermally conductive silicone rubber is cast on a copper foil, the liquid silicone rubber continuously penetrates into the micropores of the copper foil and the gap 112 of the fiber sheet 110 and comes into contact with the pressure-sensitive adhesive layer 120. Become unified.

In addition, a thermally conductive elastic member may be adhered to at least a part of the lower surface of the pressure-sensitive adhesive layer 120 by the adhesive force of the pressure-sensitive adhesive layer 120.

Hereinafter, a method of manufacturing the functional adhesive tape 100 will be described.

A fiber sheet 110 is formed by electroless plating copper having a thickness of 5 microns on a nonwoven fabric made of polyester having a thickness of 15 microns.

After casting a liquid adhesive obtained by mixing a liquid acrylic adhesive or a silicone adhesive with a metal powder having electrical conductivity and heat conduction on the lower surface of the fiber sheet 110, heat treatment, or transfer the previously prepared heat-treated electrical conductive adhesive to a thickness of 10 To form an electrically conductive adhesive layer 120 of the order of microns.

At this time, by squeezing while casting, a part of the adhesive may penetrate into the gap 112 of the fiber sheet 110.

Thereafter, a thermally conductive adhesive in which a liquid silicone rubber adhesive and thermally conductive alumina powder is mixed is cast on the upper surface of the fiber sheet 110 and cured by heat treatment to form an elastic body layer 130 having a thickness of about 150 microns.

At this time, similar to the above, the pressure-sensitive adhesive may penetrate into the gap 112 of the fiber sheet 110 by squeezing while casting.

In the above process, the liquid pressure-sensitive adhesives corresponding to the pressure-sensitive adhesive layer 120 and the elastic body 130, respectively, penetrate into the gap 112 of the fiber sheet 110 and are cured and come into contact with each other, thereby forming a heat conduction passage of a short distance.

After manufacturing the functional adhesive tape 100 into a roll by such a process, after punching out with a roll, the surface of the punched adhesive tape 100 is picked up with a vacuum pickup and mounted on the object.

2 is a cross-sectional view showing a state of use of a functional adhesive tape.

The heating element 30, such as an IC mounted on the circuit board 10 by soldering, is surrounded by a metal shield can 50 having an opening formed on the upper surface thereof.

The adhesive layer 120 is adhered to the flange around the opening so that the functional adhesive tape 100 is picked up by a vacuum pickup and covers the opening on the upper surface of the shield can 50, and the functional adhesive is adhered by the opposite metal case 20 The tape 100 is compressed.

A thermally conductive elastic pad, a thermally conductive elastic member 40 such as an elastic gel or grease is interposed on the heating element 30 located at a portion exposed through the opening of the shield can 50.

Here, the thermally conductive elastic member 40 may be made of the same material as the pressure-sensitive adhesive layer 120. For example, when the pressure-sensitive adhesive layer 120 uses a silicone pressure-sensitive adhesive, the elastic member 40 is made of silicone rubber, so that adhesion between them is It can be made to be quality, and has elasticity and thermal conductivity.

According to this structure, heat generated from the heating element 30 is transferred to the heat conductive adhesive layer 120 through the heat conductive elastic member 40 and is transferred through a number of paths as follows.

a) Adhesive layer (120)-Shield can (50)

b) Adhesive layer 120-Metal layer 111 of fiber sheet 110-Thermally conductive elastic body 130-Case 20

c) Adhesive layer 120-Thermally conductive elastic body 130 penetrating into the fiber sheet 110-Metal case 20

In addition, the electromagnetic wave generated from the heating element 30 is transmitted to the shield can 50 and is discharged to the ground. The electromagnetic wave passing through the opening of the shield can 50 is a polymer fiber sheet having an electrically conductive adhesive layer 120 and a metal layer ( 110) is transferred to the shield can 50 in the horizontal direction, and is discharged to the ground of a circuit board.

In this case, since the elastic body 130 is electrically insulated, the opposite metal case 20 in which the heating element 30 and the elastic body 130 are in elastic contact has an advantage that it can prevent electromagnetic interference by providing electrical insulation.

As a result, heat and electromagnetic waves generated from the heating element 30 can be rapidly transferred to the object in contact with the functional adhesive tape 100 and processed.

Although the above has been described with the focus on the embodiments of the present invention, it goes without saying that various changes can be made at the level of those skilled in the art. Therefore, the scope of the present invention is limited to the above-described embodiments and cannot be interpreted, and should be interpreted by the claims set forth below.

20: metal case
100: functional adhesive tape
110: polymer fiber sheet
120: electric conduction and heat conduction adhesive layer
130: electrical insulation and thermally conductive elastomer

Claims (10)

A polymer fiber sheet having an irregular size penetrating in the thickness direction, having a plurality of irregularly arranged gaps, and plated with a metal layer;
A pressure-sensitive adhesive layer that is adhered to the lower surface of the fiber sheet and has electrical and thermal conductivity properties, and has self-adhesive strength on both the upper and lower surfaces; And
It is adhered to the upper surface of the fiber sheet and includes an elastic body having electrical insulation and heat conduction properties,
The elastic body is at least twice the combined thickness of the fiber sheet and the pressure-sensitive adhesive layer,
A functional adhesive tape for surface mounting, characterized in that the pressure-sensitive adhesive layer and the elastic body are in direct contact and thermally connected by a pressure-sensitive adhesive layer portion, an elastic body portion, or both penetrating through the gap of the fiber sheet. In claim 1,
A point at which the pressure-sensitive adhesive layer and the elastic body directly contact each other is an interior of the fiber sheet, or a boundary where the pressure-sensitive adhesive layer or the elastic body and the fiber sheet meet. A functional adhesive tape for surface mounting. In claim 1,
A functional adhesive tape for surface mounting, characterized in that at least one of the pressure-sensitive adhesive layer and the liquid polymer corresponding to the elastic body penetrates through the gaps of the fiber sheet and hardens and contacts each other. In claim 1,
In the elastic body, a surface in contact with the fiber sheet has a self-adhesive force, and a surface exposed to the outside has a self-adhesive force sufficient to facilitate vacuum pickup or does not have a self-adhesive force. tape. In claim 1,
A functional adhesive tape for surface mounting, characterized in that a release film or a release paper is attached to the lower surface exposed to the outside of the adhesive layer. In claim 1,
Functional adhesive tape for surface mounting, characterized in that the thickness of the elastic body is about three times the thickness of the fiber sheet. In claim 1,
The metal layer is formed by plating with a copper layer, and the thickness of the copper layer is thicker than 1/4 of the thickness of the fiber sheet. In claim 1,
A functional adhesive tape for surface mounting, characterized in that a copper foil having a plurality of fine holes is interposed between the fiber sheet and the elastic body. In claim 8,
The fiber sheet and the copper foil, functional adhesive tape for surface mounting, characterized in that bonded to each other by the adhesion of the elastic body and the fiber sheet. In claim 1,
A functional adhesive tape for surface mounting, characterized in that a thermally conductive elastic member is adhered to at least a portion of the lower surface of the pressure-sensitive adhesive layer by the adhesive force of the pressure-sensitive adhesive layer.

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