KR20180020520A - Multilayered anisotropic conductive film - Google Patents

Abstract

Disclosed is a multilayer anisotropic conductive film with excellent anisotropy for electrical conductivity. According to an aspect of the present invention, the multilayer anisotropic conductive film comprises: an anisotropic conductive layer including graphene and a conductive filler, and having orientation to electrical conductivity; and a nonconductive layer formed on the anisotropic conductive layer.

Description

[0001] MULTILAYERED ANISOTROPIC CONDUCTIVE FILM [0002]

The present invention relates to a multilayer anisotropic conductive film.

Electronic packaging technology is an extensive and diverse system manufacturing technology that covers all stages from semiconductor devices to final products and is an important technology that determines the performance, size, cost, and reliability of the final electronics.

In liquid crystal display (LCD) packaging, a conductive adhesive is used for mechanical and electrical connection between a printed circuit board (PCB) and a transparent electrode.

Conductive adhesives include products such as anisotropic conductive film (ACF) and isotropic conductive adhesive (ICA). They are basically composed of nickel (Ni) or nickel / polymer (Ni / polymer) Ag) or the like are dispersed in thermosetting or thermoplastic insulating resin.

Japanese Patent Application Laid-Open No. 2010-073681 (Apr. 02, 2010)

According to the embodiment of the present invention, an anisotropic conductive film excellent in anisotropy against electric conductivity can be provided.

Also, according to the embodiment of the present invention, the internal stress due to the difference in the thermal expansion coefficient can be minimized, and the packaging failure can be minimized.

1 shows a multilayer anisotropic conduction film according to a first embodiment of the present invention.
2 is a view showing a multilayered anisotropic conduction film according to a modification of the first embodiment of the present invention.
3 is a view showing a multilayered anisotropic conduction film according to a second embodiment of the present invention.
4 is a view showing a multilayered anisotropic conduction film according to a third embodiment of the present invention.
5 is a view schematically showing a method of manufacturing an anisotropic conductive layer applied to an embodiment of the present invention.
Fig. 6 is a view showing Fig. 5 (B). Fig.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. In the specification, "on" means to be located above or below the object portion, and does not necessarily mean that the object is located on the upper side with respect to the gravitational direction.

In addition, the term " coupled " is used not only in the case of direct physical contact between the respective constituent elements in the contact relation between the constituent elements, but also means that other constituent elements are interposed between the constituent elements, Use them as a concept to cover each contact.

The sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

Hereinafter, embodiments of the multilayered anisotropic conduction film according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components are denoted by the same reference numerals, The description will be omitted.

Multilayer anisotropic conductive film

(First Embodiment and Modifications)

1 is a view showing a multilayered anisotropic conduction film according to a first embodiment of the present invention.

Referring to FIG. 1, a multilayer anisotropic conduction film 1000 according to the first embodiment of the present invention includes an anisotropic conductive layer 100, a nonconductive layer 200, and a protective layer 10.

The anisotropic conductive layer 100 includes a graphene 120 and a conductive filler 130, and has an orientation to electrical conductivity. Since the graphene 120 of the anisotropic conductive layer 100 and the conductive filler 130 are oriented in one direction in the first insulating resin 110, the anisotropic conductive layer 100 has electrical conductivity only in the one direction. In this specification, the anisotrophic conduction layer 100 has a directionality to the electrical conductivity, which means that the electrical conductivity of one of the xyz axes of the anisotropic conduction layer 100 is greater than the electrical conductivity of the other axis it means. Most preferably electrically conductive for one axis and electrically insulating for the other axis, but is not limited thereto.

The first insulating resin 110 is selected to have electrical insulation among a thermosetting resin, a thermoplastic resin, a photocurable resin, or a mixture thereof. The first insulating resin 110 may be composed of at least one selected from the group consisting of a liquid crystal polymer (LCP) and an epoxy resin. As the epoxy resin, bisphenol A type epoxy resin, naphthalene modified epoxy resin, cresol novolak epoxy resin, rubber deformable epoxy resin and the like can be used.

The first insulating resin 110 may be formed in a semi-cured state (B-stage) to maintain the orientation direction of the graphene 120 until packaging.

The graphene 120 is a plate-like material having a hexagonal ring of carbon atoms, and has excellent electrical conductivity and excellent physical mechanical properties.

The graphene 120 is oriented in one direction in the first insulating resin 110. By orienting the electrically conductive graphene 120 in one direction, the anisotropic conductive layer 100 can have electrical conductivity only in one direction. A detailed method of orienting the graphene 120 in the first insulating resin 110 in one direction will be described later.

The graphene 120 is oriented in the thickness direction of the anisotropic conductive layer 100. Thus, the printed circuit board and the semiconductor die can be electrically connected to each other along the thickness direction of the anisotropic conductive layer 100. Due to the orientation direction of the graphene 120, the anisotropic conductive layer 100 has electrical insulation in the planar direction. Therefore, in the packaging of the printed circuit board and the semiconductor die, between the pads of the adjacent printed circuit boards arranged in the surface direction of the anisotropic conductive layer 100, between the bumps of the adjacent semiconductor dies or between the adjacent pad- Respectively.

The pads of the printed circuit board and the bumps of the semiconductor die refer to external connection means formed on the printed circuit board and the semiconductor die, respectively. That is, the pads and bumps herein have the same function as the conventional external terminals of an electronic device. Therefore, it should be understood that the present invention belongs to the scope of the present invention regardless of its name, if it has the same function as the pad and bump of the present invention.

The conductive filler 130 is a particle of an electrically conductive material and is dispersed in the first insulating resin 110. 1, the conductive filler 130 is oriented in one direction together with the graphene 120, and the conductive filler 130 enhances the current density of the multilayer anisotropic conduction film 1000 according to the present embodiment. And the moldability of the anisotropic conductive layer 100 applied to the present embodiment can be improved.

The conductive filler 130 may comprise a metal and / or an alloy. Specifically, the conductive filler 130 may include at least one selected from the group consisting of copper, gold, silver, nickel, and alloys thereof.

The conductive filler 130 may be formed of a conductive material coated on the surface of the core and the core of the nonconductive material, or may be formed of only the conductive particles.

Since the conductive filler 130 may be formed in various shapes such as spherical, hemispherical, polygonal, cylindrical, or plate shapes, the shape of the conductive filler 130 shown in FIG. 1 and the like should be understood as an example.

The diameter of the conductive filler 130 may be variously selected from several nm to several tens of micrometers. When the conductive filler 130 is not spherical, the diameter of the conductive filler 130 refers to the length of each of a plurality of line segments passing through two different points on the surface of the conductive filler 130 and passing through the center of gravity of the conductive filler 130 Is used to mean the longest of the two.

The nonconductive layer 200 comprises a second insulating resin 210 and graphene oxide 220 and is formed on the anisotropic conductive layer 100.

The second insulating resin 210 is selected to have electrical insulation among a thermosetting resin, a thermoplastic resin, a photocurable resin, or a mixture thereof. The second insulating resin 210 may be composed of at least one selected from the group consisting of a liquid crystal polymer (LCP) and an epoxy resin. As the epoxy resin, bisphenol A type epoxy resin, naphthalene modified epoxy resin, cresol novolak epoxy resin, rubber deformable epoxy resin and the like can be used.

The second insulating resin 210 may be formed in a semi-cured state (B-stage) to prevent deformation of the non-conductive layer 200 until packaging, and improve workability in packaging.

The oxide graphene 220 is a material dispersed in the second insulating resin 210 and corresponds to the oxide of the graphene 120 described above and has electrical nonconductivity. The oxidized graphene 220 has similar thermal and mechanical properties to the graphene 120 except for electrical properties.

The protective layer 10 is formed on the upper surface of the nonconductive layer 200 and the lower surface of the anisotropic conductive layer 100 to protect the multilayer anisotropic conduction film 1000 according to the present embodiment from the outside. The protective layer 10 may be a conventional protective film formed at an outermost edge of a film material provided in the form of a multilayer film of a material used for processing a printed circuit board. Therefore, the protective layer 10 of this embodiment has the same function as a conventional carrier film, release film, protective film, or the like.

The protective layer 10 is separated from the nonconductive layer 200 and the anisotropic conductive layer 100, respectively, upon packaging. That is, at the time of packaging, only the anisotropic conductive layer 100 and the nonconductive layer 200 of the multilayer anisotropic conduction film 1000 according to the present embodiment are selectively used. A releasing material may be applied to one side of the protective layer 10 for easy removal of the protective layer 10 during packaging.

The multilayer anisotropic conduction film 1000 according to the present embodiment can be applied to packages of various designs. For example, the multilayer anisotropic conduction film 1000 according to the present embodiment can be used not only for packaging a printed circuit board and a semiconductor device, but also for packaging a transparent electrode such as a printed circuit board and an ITO of a liquid crystal display.

2 is a view showing a multilayer anisotropic conduction film according to a modification of the first embodiment of the present invention.

Referring to FIG. 2, a multilayer anisotropic conduction film 1000 'according to a modification of the first embodiment of the present invention is the same as the structure of the first embodiment except for the graphene oxide (220 in FIG. 1) Exemplary oxide graphene (220 in FIG. 1) is replaced with an inorganic filler (230).

The inorganic filler 230 may be at least one selected from the group consisting of alumina, silica, glass, and silicon carbide, and mixtures thereof. However, if the inorganic filler 230 is an electrically nonconductive inorganic material such as various metal oxides or metal nitrides, May be included in the inorganic filler 230 of the modified example.

Since the inorganic filler 230 can be formed into various shapes such as spherical, hemispherical, polygonal, cylindrical or plate shapes, the shape of the inorganic filler 230 shown in FIG. 2 should be understood as an example.

The diameter of the inorganic filler 230 may be variously selected from the range of several nanometers to several tens of micrometers. When the inorganic filler 230 is not spherical, the diameter of the inorganic filler 230 refers to the length of each of a plurality of line segments connecting two different points on the surface of the inorganic filler 230 and passing through the center of gravity of the inorganic filler 230 Is used to mean the longest of the two.

The multilayer anisotropic conduction film 1000 'according to the present modification can vary the content of the inorganic filler 230 according to design requirements. In addition, the multilayer anisotropic conduction film 1000 'according to the present modification may further include an electrically insulating organic filler except for the graphene oxide (220 in FIG. 1) according to design requirements.

In this modification, the coefficient of thermal expansion of the nonconductive layer 200 may be similar to the coefficient of thermal expansion of the semiconductor die.

(Second Embodiment)

3 is a view showing a multilayer anisotropic conduction film according to a second embodiment of the present invention.

Referring to FIG. 3, the multilayer anisotropic conduction film 2000 according to the second embodiment of the present invention includes an anisotropic conductive layer 100, a nonconductive layer 200, and a protective layer 10. In comparison with the first embodiment of the present invention, the non-conductive layer 200 is different, and the remaining configurations are the same as those of the first embodiment of the present invention. Accordingly, the non-conductive layer 200, which differs from the first embodiment of the present invention, will be mainly described below.

The nonconductive layer 200 includes a second insulating resin 210, an oxidized graphene 220 and an inorganic filler 230. The inorganic filler 230 and the oxidized graphene 220 are chemically bonded to each other, Is dispersed in the second insulating resin 210 in the form of a filler-oxidized graphene composite material (Composite).

The formation of inorganic filler-oxidized graphene composite material can be explained by the functional groups of -COOH, -OH and -COC- (epoxy ring) existing on the surface of the oxide graphene 220 and the functional groups of the inorganic filler 230 An inorganic filler-oxidized graphene composite material having a -COC- and -CNC- functional group is formed according to an acid-base reaction between the functional groups of -OH and -NH existing on the surface of the substrate.

FIG. 3 illustrates that the inorganic filler 230 applied to the present embodiment is all bonded to the oxide graphene 220. However, the inorganic filler 230 is not limited to the inorganic filler- The case where the filler 230 is dispersed in the second insulating resin 210 is naturally also within the scope of the present invention.

Since the nonconductive layer 200 includes the graphene 220 having similar thermal mechanical properties to the graphene 120 included in the anisotropic conductive layer 100, the anisotropic conductive layer 100 and the nonconductive It is possible to minimize the generation of stress in the interlayer of the layer 200. In this embodiment, since the nonconductive layer 200 includes the inorganic filler 230 having similar thermal and mechanical properties to the inorganic material that is the main constituent material of the semiconductor die, the multilayer anisotropic conduction film 2000 and The thermal mechanical coupling between the semiconductor dies can be improved.

(Third Embodiment)

4 is a view showing a multilayer anisotropic conduction film according to a third embodiment of the present invention.

Referring to FIG. 4, a multilayer anisotropic conduction film 3000 according to a third embodiment of the present invention includes an inner layer 100, a buffer layer 200, an outer layer 300, and a protective layer 10. The inner layer 100 and the protective layer 10 according to the present embodiment correspond to the anisotropic conductive layer (100 in FIG. 1) and the protective layer (10 in FIG. 1) according to the first embodiment of the present invention. The buffer layer 200 and the outer layer 300 will be mainly described in this embodiment.

As compared with the first embodiment, the modification of the first embodiment and the second embodiment, the present embodiment is different from the first embodiment, the modification of the first embodiment, and the nonconductive layer described in the second embodiment 1 to 200 of FIG. 3) are combined to form the buffer layer 200 and the outer layer 300 of the present embodiment, which are non-conductive layers of a bilayer structure.

That is, the buffer layer 200 applied to this embodiment is the same as the nonconductive layer (200 of FIG. 3) described in the second embodiment of the present invention, and the outer layer 300 applied to this embodiment is the same as the non- Is the same as the nonconductive layer (200 in Fig. 2) described in the modification of one embodiment.

The buffer layer 200 is formed of a graphene 120 and an outer layer 300 of the inner layer 100 and the outer layer 300. The buffer layer 200 is formed of a triple layer structure of an inner layer 100, a buffer layer 200, It is possible to prevent a sharp change in the thermal expansion coefficient between the inner layer 100 and the outer layer 300 because the layer includes the oxidation graphene 220 and the first inorganic filler 230 having thermal mechanical properties similar to those of the second inorganic filler 330 . Therefore, the occurrence of internal stress due to the unevenness of the thermal expansion coefficient can be minimized.

Method for manufacturing multilayer anisotropic conduction film

5 is a view schematically showing a method of manufacturing an anisotropic conductive layer according to an embodiment of the present invention.

Hereinafter, a manufacturing method for manufacturing the multilayer anisotropic conduction film (3000 in Fig. 4) according to the third embodiment of the present invention will be described.

First, a first varnish (V1) in which graphene and a conductive filler are dispersed in a first insulating resin, a second varnish in which graphene oxide and a first inorganic filler are dispersed in a second insulating resin, A third varnish dispersed in the resin is prepared. Each of the first varnish, the second varnish and the third varnish corresponds to the raw material which is the inner layer (100 in FIG. 4), the buffer layer (200 in FIG. 4) and the outer layer (300 in FIG. 4) described in the third embodiment of the present invention do.

The first varnish V1 is formed by mixing the graphene and the conductive filler, and then dispersing the mixed graphene and the conductive filler in the first insulating resin.

The second varnish is formed by mixing the graphene oxide and the first inorganic filler, and then dispersing the mixed graphene grains and the first inorganic filler in the second insulating resin. The graphene oxide and the first inorganic filler may form an inorganic filler-oxidized graphene composite material as described above in the mixing step or the dispersing step.

Graphene may be prepared from graphite, or by cutting a carbon nanotube, or by a CVD (chemical vapor deposition) process using methane as a carbon source.

Methods for producing graphene from graphite are roughly divided into mechanical peeling and physico-chemical peeling.

In the mechanical peeling method, an adhesive tape or the like is attached to graphite and peeling off is repeated to remove graphene laminate structure, thereby producing graphene.

The physico-chemical stripping method causes an oxidation reaction between the surface of the graphite and the interlayer structure in a state in which the graphite lumps having the laminated structure are dispersed in an appropriate solvent, widening the space between the layers and again adsorbing other substances on the surface thereof, And completely peeling it off.

In more detail, the graphene laminated in the form of graphite is first modified by ionic functional groups such as a carboxyl group, a hydroxyl group, a sulfonyl group and an amine group to the surface or the terminal, both the surface and the end of graphene, Thereby destroying the laminated structure of the graphite. Thereafter, graphene is produced by reducing both the surface and the end, both the surface and the end, of the oxidized graphene through a reduction reaction.

Methods for modifying graphene to have a carboxyl group and a hydroxyl group and for reducing the oxidized graphene can be used in all methods commonly used in the art. For example, there is a method of grinding and oxidizing graphite to prepare oxidized graphite, treating the oxidized graphite with ultrasonic waves to obtain oxidized graphene, and treating the graphene oxide with hydrazine and ammonia to obtain graphene.

The first insulating resin, the second insulating resin and the third insulating resin are selected to have electrical insulation among a thermosetting resin, a thermoplastic resin, a photocurable resin, or a mixture thereof. The first insulating resin, the second insulating resin and the third insulating resin may be composed of at least one selected from the group consisting of a liquid crystal polymer (LCP) and an epoxy resin. As the epoxy resin, bisphenol A type epoxy resin, naphthalene modified epoxy resin, cresol novolak epoxy resin, rubber deformable epoxy resin and the like can be used.

5, the first varnish V1 is applied to the protective layer 10 (A), and an electric field or a magnetic field is applied to the first varnish V1 to cause the graphene and the conductive filler to move in one direction (B), and the first varnish (V1) is dried (C) in a semi-cured state to form an inner layer (100 in Fig. 4).

6, the upper surface of the graphene 120 and the lower surface of the conductive filler 130 may be arranged so that the upper surface of the graphene 120 and the lower surface of the conductive filler 130 are arranged in the electric field, 1 < / RTI > varnish V1. Alternatively, the graphene 120 and the conductive filler 130 may be disposed on the first varnish (not shown) even if the top surface is arranged so as to have a positive pole and the bottom surface as a positive pole in the electric field, V1).

In the drying step (C), the first varnish V1 is dried so that the first insulating resin can fix the graphene 120 and the conductive filler 130. Through this process, the first insulating resin of the inner layer is semi-hardened State can be maintained.

Although not shown in the drawing, after the drying step is completed, a second varnish may be coated on the inner layer, followed by drying to form a buffer layer, applying a third varnish on the buffer layer, and drying the outer layer. Finally, by forming the protective layer on the outer layer, the multilayer anisotropic conduction film according to the third embodiment of the present invention can be produced.

The process of forming the buffer layer and the outer layer with the second varnish and the third varnish, respectively, is similar to the above-described process of forming the inner layer, so a detailed description will be omitted. However, the orientation process (B) during the inner layer formation process may be omitted in the process of forming the buffer layer and the outer layer.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

V1: First varnish
10: Protective layer
100: anisotropic conductive layer, inner layer
110: first insulating resin
120: Graphene
130: Conductive filler
200: nonconductive layer, buffer layer
210: second insulating resin
220: oxidized graphene
230: first inorganic filler
300: outer layer
310: Third insulating resin
330: second inorganic filler
1000, 1000 ', 2000, 3000: multilayer anisotropic conductive film

Claims (10)

An anisotropic conductive layer comprising a graphene and a conductive filler, the anisotropic conductive layer having a directivity to electrical conductivity; And
A nonconductive layer formed on the anisotropic conductive layer;
/ RTI >
The method according to claim 1,
Wherein the graphene is oriented in the thickness direction of the anisotropic conductive layer.
The method according to claim 1,
Wherein the conductive filler comprises a metal and / or an alloy.
The method according to claim 1,
Wherein the nonconductive layer is a multi-layer anisotropic conductive film comprising graphene oxide
5. The method of claim 4,
Wherein the nonconductive layer further comprises an inorganic filler.
6. The method of claim 5,
Wherein the inorganic filler is bonded to the surface of the graphene oxide.
The method according to claim 1,
The non-
A first nonconductive layer comprising graphene oxide and a first inorganic filler, the first nonconductive layer being formed on the anisotropic conductive layer,
And a second non-conductive layer formed on the first non-conductive layer, the second non-conductive layer including a second inorganic filler.
An inner layer having a first insulating resin, a graphene dispersed in the first insulating resin, and a conductive filler dispersed in the first insulating resin, the inner layer having an electric conductivity;
A buffer layer comprising a second insulating resin, Graphene Oxide dispersed in the second insulating resin, and a first inorganic filler bonded to the surface of the oxide graphene (Graphene Oxide)
An outer layer comprising a third insulating resin and a second inorganic filler dispersed in the third insulating resin;
/ RTI >
9. The method of claim 8,
Wherein the graphene is oriented in the thickness direction of the anisotropic conductive layer.
9. The method of claim 8,
Wherein the first insulating resin, the second insulating resin, and the third insulating resin are in a semi-cured state.

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