KR101371102B1 - Composition for Conductive Adhesive, Adhesive Film and Circuit Board Using the Same - Google Patents

Abstract

In the present invention with respect to 100 parts by weight of the silicone adhesive; 5 to 50 parts by weight of silicone resin; And it provides a conductive silicone pressure-sensitive adhesive composition, a pressure-sensitive adhesive film and a circuit board using the carbon nanotubes 0.01 to 5 parts by weight.
The conductive adhesive film including the carbon nanotubes of the present invention has excellent conductivity compared to using metal-based particles such as gold or silver as a result of using carbon nanotubes as conductive particles which are materials for implementing conductivity. Small density of carbon nanotubes has the advantage that the target conductivity can be achieved even in a relatively small amount. In addition, the conductive silicone pressure sensitive adhesive of the present invention does not require a long-term thermocompression process at a high temperature required for adhesion with the adhesive in the conventional thermosetting adhesive due to the excellent adhesive properties of the silicone resin, and is deposited only by a simple compression process at room temperature. Because of the excellent adhesion characteristics with the agent, the process time can be shortened and the process cost can be reduced.

Description

Composition for Conductive Adhesive, Adhesive Film and Circuit Board Using the Same

The present invention relates to a conductive pressure-sensitive adhesive composition, a conductive pressure-sensitive adhesive film and a circuit board using the same, and more particularly, carbon nanotubes are dispersed in a silicone binder resin and excellent in electrical conductivity and adhesive properties and excellent adhesive properties only by a simple pressing process at room temperature It relates to a conductive pressure-sensitive adhesive composition for a circuit board, a conductive pressure-sensitive adhesive film and a circuit board using the same.

Glass epoxy resins have been used as a reinforcing plate material of a conventional circuit board, but a thin reinforcing plate is required for miniaturization, and a stainless steel reinforcing plate is replaced by this.

In order to adhere such a reinforcing plate to the flexible circuit board, an adhesive sheet having electrical insulation (eg, a bonding sheet, a stiffener adhesive film) is conventionally used. However, in the case of using a stainless steel reinforcing plate, in addition to the reinforcing effect, connecting the stainless plate and the electrode of the flexible circuit board in order to express the EMI shielding effect by connecting the stainless plate to the ground layer. Designed.

For example, the conventional adhesive sheet is electrically insulating, so that even when a metal is used as the reinforcing plate, no electrical connection is made, and thus a reinforcing effect is obtained, but it is not possible to flow a current through the reinforcing plate of the metal. It was also not possible to express the effect and hence the stabilization of the circuit signal.

In addition, the existing FPCB process mainly uses thermosetting resins, especially epoxy resins, and thus requires a long time thermocompression process at high temperature, resulting in a prolonged process time and an increase in process cost. Although acrylic resin, which is the main material of adhesive resin, has the disadvantage of being vulnerable to the thermal process required in the FPCB process, a thermosetting adhesive has been mainly used.

Accordingly, the present inventors have made diligent efforts to overcome the above-mentioned disadvantages of the conventional FPCB process adhesives, and when the carbon nanotubes are dispersed in the pressure-sensitive silicone adhesive and used as a conductive material, the circuit board body such as FPCB and the reinforcing plate made of metal It was confirmed that the same circuit components and the like can be electrically interconnected and exhibit excellent adhesion characteristics through a simple roll lamination process at room temperature.

It is an object of the present invention to provide a pressure-sensitive adhesive composition in which carbon nanotubes are dispersed in a silicone binder, which has excellent conductivity and exhibits excellent adhesive properties with the adherend only by a simple pressing process at room temperature.

Another object of the present invention is to provide a conductive adhesive film using the composition.

Still another object of the present invention is to provide a circuit board manufactured using the pressure-sensitive adhesive composition.

Conductive silicone pressure-sensitive adhesive composition of the present invention for achieving the above object is based on 100 parts by weight of silicone pressure-sensitive adhesive; 5 to 50 parts by weight of silicone resin; And 0.01 to 5 parts by weight of carbon nanotubes.

The silicone pressure-sensitive adhesive (iii) diorganopolysiloxane capped with alkenyl groups at both ends of the molecule (viscosity of 5 × 10 ⁵ cP or more); Ⅱ) R ₃ SiO _1/2 units (wherein, R is an alkyl, alkenyl or hydroxyl group) and an organopolysiloxane resin composed of SiO _4/2 units; Iii) organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, which has from 1 to 20 silicon-bonded hydrogen atoms per one alkenyl group of component diorganopolysiloxane; And iii) an organic solvent. It is preferable that it is a pressure-sensitive adhesive composition containing.

The silicone resin is preferably a polydialkylsiloxane having a structure represented by the following formula (1):

[Chemical Formula 1]

Wherein R is a methyl or phenyl group.

The average length of the carbon nanotubes is preferably 0.01 ~ 20㎛.

In the conductive adhesive film of the present invention, the conductive silicone adhesive is coated on a release substrate.

At this time, it is preferable that the coating thickness of the said conductive silicone adhesive is 10-100 micrometers.

The circuit board of the present invention is characterized in that the main body and the circuit component are adhered and electrically connected by a conductive adhesive layer containing carbon nanotubes having an average diameter of 0.01 to 20 µm.

The conductive adhesive film including the carbon nanotubes of the present invention has excellent conductivity compared to using metal-based particles such as gold or silver as a result of using carbon nanotubes as conductive particles which are materials for implementing conductivity. Small density of carbon nanotubes has the advantage that the target conductivity can be achieved even in a relatively small amount.

In addition, the conductive silicone pressure sensitive adhesive of the present invention does not require a long-term thermocompression process at a high temperature required for adhesion with the adhesive in the conventional thermosetting adhesive due to the excellent adhesive properties of the silicone resin, and is deposited only by a simple compression process at room temperature. Because of the excellent adhesion characteristics with the agent, the process time can be shortened and the process cost can be reduced.

1.Conductive Silicone Adhesive Composition

The conductive silicone pressure-sensitive adhesive composition of the present invention is based on 100 parts by weight of the silicone pressure-sensitive adhesive; 5 to 50 parts by weight of silicone resin; And 0.01 to 5 parts by weight of carbon nanotubes. Hereinafter, each composition of the electrically conductive silicone adhesive composition of this invention is demonstrated in detail.

1-1. Silicone adhesive

The silicone adhesive applied to the conductive silicone adhesive composition of the present invention refers to a silicone pressure-sensitive adhesive composition. The silicone-based pressure-sensitive adhesive composition ⅰ) organopolysiloxane resin composed mainly of a diorganopolysiloxane capped with both ends of a molecule are alkenyl groups consisting of Al ⅱ) R ₃ SiO _1/2 units and SiO _4/2 units; Iii) organopolysiloxanes having at least two silicon-bonded hydrogen atoms in one molecule; Iii) platinum based catalysts; And iii) an organic solvent.

More specifically, the pressure-sensitive silicone pressure-sensitive adhesive iii) 100 parts by weight of diorganopolysiloxane (viscosity of 5 × 10 ⁵ cP or more) capped with alkenyl groups at both ends of the molecule; Ⅱ) R ₃ SiO _1/2 units (wherein, R is alkyl, alkenyl or hydroxyl group a) and SiO _4/2 unit of organopolysiloxane resin 25 to 150 parts by weight ⅲ consisting of) two or more silicon-bonded in one molecule To 30 parts by weight of an organopolysiloxane having a hydrogen atom, which has 1 to 20 silicon-bonded hydrogen atoms per one alkenyl group of the component diorganopolysiloxane; Iii) 3 to 8 parts by weight of a platinum catalyst; And iii) 30 to 50 parts by weight of an organic solvent.

The silicone-based adhesives are superior in terms of electrical insulation, heat resistance, resistance to frost, and adhesion to various substrates compared to acrylic or rubber-based adhesive compositions.

The silicone pressure-sensitive adhesive used in the present invention has the advantage of being able to control the adhesive force with the adherend by adjusting the composition ratio of the silicone pressure-sensitive adhesive as a main component that shows the adhesive force of the pressure-sensitive adhesive made through the present invention.

1-2. Silicone resin

Silicone resin applied to the conductive silicone pressure-sensitive adhesive composition of the present invention is a polydialkylsiloxane having a structure represented by the following general formula (1):

[Chemical Formula 1]

Wherein R is a methyl or phenyl group.

The silicone resin has a property of forming a hard film and a molded article when cured in comparison with silicone oil and silicone rubber, and has the following characteristics.

(1) Heat resistance: One of the excellent properties of silicone resin is heat resistance. Compared with other resins, the amount of thermal decomposition is very small, and the higher the silicon content, the less the change in gloss.

(2) Electrical characteristics: Silicone resin has excellent electrical insulation and can be used in a wide temperature range. In addition, there is little polarity, so frequency dependence is low and carbonization is low.

(3) Moisture / Water Resistance: Silicone resin has excellent water resistance and moisture resistance because it does not have a polar group compatible with water and has a large contact angle with water.

(4) Chemical resistance: Silicone varnish improves chemical resistance as it denatures to organic index.

(5) Weather resistance: Silicone varnish has excellent weather resistance. As the base resin of the road, silicon modified varnishes are often used because of superior price, curing speed, mechanical strength, and adhesiveness than pure silicon.

(6) Flame retardant: When the silicon varnish coating is brought into contact with fire, some sparks appear and burn, but when the flame is far away, they are soon extinguished. In other words, a large amount of oxygen is required for combustion, so the flame retardancy is high.

The silicone resin used in the present invention plays an important role in improving the heat resistance of the pressure-sensitive adhesive made through the present invention, and has an advantage of improving heat resistance by controlling the composition ratio of the silicone resin in the composition ratio of the pressure-sensitive adhesive composition.

The content of the silicone resin is 5 to 50 parts by weight, preferably 10 to 30 parts by weight based on 100 parts by weight of the silicone adhesive. When the content of the silicone resin is less than 5 parts by weight, a problem of decreasing the heat resistance of the pressure-sensitive adhesive composition occurs, and when it exceeds 50 parts by weight, it is not preferable because the adhesive properties are lowered.

1-3. Carbon nanotube

In the present invention, the carbon nanotube refers to an allotrope of carbon having a hollow cylindrical nanostructure. The carbon nanotubes include single-walled nanotubes (SWNTs) as well as multi-walled nanotubes (MWNTs). Among them, single-walled carbon nanotubes have an excellent electrical conductivity compared to multi-walled carbon nanotubes, but the price competitiveness is significantly lower.

The carbon nanotubes used in the present invention are not particularly limited as long as the object of the present invention is not impaired, and commercially available products can be purchased and used. For example, those manufactured by conventional arc discharge, laser ablation, high temperature filament plasma chemical vapor deposition, microwave plasma chemical vapor deposition, thermochemical vapor deposition or pyrolysis can be used. In the present invention, a commercially available product was used as it is, but if necessary, an additional process removes carbon-containing materials such as amorphous carbon and fullerene as by-products in the manufacturing process and transition metals used as a catalyst for growth of tubes. You can also use

Commercially available carbon nanotubes include, for example, C-Tube_100, Hanwha Nanotech CM-100, Carbon Nanotech CNT-M95, and the like.

However, the carbon nanotubes preferably use an average length of 0.01 ~ 20㎛. When the average length is less than 0.01 μm, the reliability of electrical connection is inferior in physical point. When the average length is more than 20 μm, the carbon nanotube particles are entangled in the normal temperature compression process when used as an adhesive film. It will adversely affect the conductivity.

The amount of the carbon nanotubes added to the pressure-sensitive adhesive composition is added to 0.01 to 5 parts by weight of carbon nanotubes, preferably 0.05 to 2 parts by weight, based on 100 parts by weight of the silicone pressure-sensitive adhesive. If the amount is less than 0.01 parts by weight, the viscosity of the pressure-sensitive adhesive solution is too low when mixed with the conductive pressure-sensitive adhesive solution, and if it exceeds 5 parts by weight, the viscosity of the dispersion is so high that the dispersibility of carbon nanotubes in the silicone composition is poor. There is this.

2. Preparation of conductive adhesive film

2-1. Preparation of Carbon Nanotube Dispersion

The carbon nanotubes are dispersed in an organic solvent having high polarity and mixed with the above-described silicone pressure sensitive adhesive and silicone resin in a carbon nanotube dispersion state. As an organic solvent used for this purpose, solvents, such as dimethylformamide (DMF), ethylene glycol, and dimethyl sulfoxide (DMSO), can be used individually or in mixture of 2 or more types, for example. Especially preferably dimethyl formamide (DMF) is used.

Two methods may be used to prepare the dispersion of the carbon nanotubes. First, there is a chemical method of dispersing using a dispersant, and then there is a physical dispersing method such as ultrasonic dispersion, and the two methods may be used in parallel.

The chemical dispersing method does not affect the conductivity of the carbon nanotubes, such as sodium dodecyl sulfate or polyoxyethylene tert-octylphenyl ether, but only serves to help dispersing the carbon nanotubes. How to use

Ultrasonic dispersion method is widely used as the physical dispersion method, as the ultrasonic waves used may be both long wavelength or short wavelength ultrasonic waves, but in the case of long wavelengths, since the amplitude is too small, it is difficult to produce large energy. It is preferable to use probe type ultrasonic waves having a large amplitude. Preferably, the above chemical and physical dispersion methods are used in parallel.

2-2. Kneading with Silicone Adhesive and Silicone Resin

Next, the prepared carbon nanotube dispersion is kneaded with a silicone pressure sensitive adhesive and a silicone resin to obtain a conductive silicone pressure sensitive adhesive composition including a solvent. At this time, the viscosity of the pressure-sensitive adhesive composition after kneading is preferably 100 to 5,000cps, preferably 500 to 4000cps. When the viscosity of the pressure-sensitive adhesive composition is less than 100 cps, the thickness of the pressure-sensitive adhesive sheet may not be adjusted when the pressure-sensitive adhesive composition is coated, and the coating surface may be very uneven when coated on a release substrate. In addition, when the pressure exceeds 5,000 cps, bubbles are excessively generated when the pressure-sensitive adhesive composition is agitated, and thus the coating thickness is very difficult to control in the process described later, which is not preferable.

2-3. Application to release materials

The conductive adhesive film of the present invention is prepared by applying the kneaded material on a release substrate and then drying.

At this time, as the release substrate used, a film of PET or PP material is used, and in particular, a silicone or fluorine-based coating on the film is preferable because of its excellent release force.

On the other hand, the coating method may be used as long as it can be used for the application of a conventional pressure-sensitive adhesive, for example, a gravure coat method (blade coat method), blade coat (blade coat method), wire bar coat (wire bar coat) Method, reverse coat method, comma coat method and the like can be used. Among these, the comma coating method is preferable because the coating thickness can be easily adjusted as the distance between the comma coater and the substrate surface.

After the coating, the coating is dried to remove the organic solvent. At this time, the drying is carried out for 2 to 10 minutes at 100 to 160 ℃, whereby the organic solvent is removed to prepare a conductive film coated with a semi-cured composition on the release substrate.

It is preferable that the thickness of the application | coating thickness after drying of the produced conductive film-form adhesive composition is 10-100 micrometers. If the coating thickness is less than 10㎛ there is a problem that the adhesive strength when applied to the FPCB product as a pressure-sensitive adhesive or difficult to sufficiently fill the step of the product, if it exceeds 100㎛ there is a disadvantage that it is difficult to control the overall thickness of the FPCB product.

By using the conductive adhesive film using the adhesive of the present invention, when the circuit board main body and the circuit parts having the electrodes are adhered to the surface and the circuit board is formed, it is possible to reliably electrically connect the electrodes through the carbon nanotubes. .

In particular, in the case of using carbon nanotubes as the conductive material, there is an advantage that the surface of the electrode physically less than the metal particles. That is, in the case of metal particles, it is difficult to balance the pressure due to the metal particles at the time of processing, and the reliability of the electrical connection is inferior from the viewpoint of particle penetration by the insulating layer in the circuit board main body. However, carbon nanotubes are also very small in size and are made of fiber (fiber) form, which has the advantage of being free from the above problems.

In addition, since the conductive silicone pressure-sensitive adhesive of the present invention uses carbon nanotubes without using metal particles, it does not contain a reducing additive in the pressure-sensitive adhesive. In general, a conductive adhesive film that obtains conductivity through metal particles contains a reducing additive such as flux to more easily form metal bonds of the metal particles introduced into the adhesive, but since the flux is active, it may cause adhesive and gelation. There is a fatal drawback that it can.

The conductive silicon adhesive layer containing the carbon nanotubes of the present invention not only reinforces the circuit board main body and stabilizes the circuit signal, but also improves the electrical conductivity reliability between the circuit board main body and the circuit components. . Moreover, the circuit board main body which has a groove bottom on the surface, and the electrode formed in the bottom part of the said groove bottom can provide the circuit board which is electrically connected with high reliability. Moreover, when a circuit component is a metal reinforcement board, an electron shielding effect can be exhibited in a metal reinforcement board.

Hereinafter, the present invention will be described in more detail with reference to Examples. This is for explaining the present invention more specifically, but the scope of the present invention is not limited to these Examples.

<Examples 1-6>

In the case of the carbon nanotube dispersion, the solid contents of the dispersion are set to 0.01 to 2 wt%, and carbon nanotubes are added to the DMF solvent to add a dispersant (sodium dodecyl sulfate) to 0.3% by weight relative to the solids, and then ultrasonic wave ( probe type ultrasonic) was added for 30 to 60 minutes to prepare. Single-walled carbon nanotubes are used by Hanwha Nanotech Co., Ltd., HANOS ASA-100F (diameter: 1.3 ~ 1.5nm, Purity: 20wt% (30vol%)), and multi-walled carbon nanotubes are manufactured by CNT Co., Ltd. C-Tube_100 (bulk) density: 0.03-0.06 g / cm ³ and specific surface area: 150-250 m ² / g).

The conductive silicone pressure-sensitive adhesive composition was prepared as follows using the carbon nanotube dispersion. 100 parts by weight of the silicone adhesive (DowCorning, Q2-7735) and 20 parts by weight of the silicone resin (DowCorning. 7466) were uniformly stirred, followed by adding the prepared carbon nanotube dispersion to contain 0.01 wt% to 1 wt% of the single wall carbon nanotubes. The prepared conductive silicone adhesive was prepared.

In the same manner, 0.1 wt% of the multi-walled carbon nanotube dispersion was prepared, and 0.06 parts by weight to 2.4 parts by weight of the silicone pressure-sensitive adhesive composition, followed by high-speed stirring, containing the conductive silicone pressure-sensitive adhesive containing 0.05wt% to 2wt% of the multiwall carbon nanotubes. The composition was prepared.

They were transferred to a pump and coated on a fluorine coated release film (silicon-based fluorine release film, ESD Korea, HFK-500) having a continuous coating thickness of 100 μm. The substrate coated with the silicone pressure sensitive adhesive composition was passed through an in-line dryer, dried at 50 to 100 ° C. for 2 to 10 minutes to remove the organic solvent, and dried to form a conductive adhesive film with a coating thickness of 40 μm, and then rewound as it is ( Rewinding) or by using a roll laminator and a separate fluorine release film by crimping and then rewinding to prepare a conductive silicone adhesive film.

<Comparative Example 1-5>

In the above embodiments, silver particles (Automize, TSC-20D18) is added in place of carbon nanotubes to prepare a silver particle dispersion by mixing with a silicone pressure-sensitive adhesive and silicone resin mixture to prepare a conductive silicone pressure-sensitive adhesive Except for preparing the same as in Example 1 to prepare a conductive silicone adhesive film.

<Comparative Example 6-8>

In the above embodiments, the conductive silicone pressure-sensitive adhesive film was prepared in the same manner as in the embodiments except that the carbon nanotube dispersion liquid was added to the epoxy composition, the urethane composition, and the acrylic resin composition in place of the silicone composition. It was.

Epoxy resin composition is a non-halogen epoxy, 80 parts by weight of carboxyl group-containing acrylonitrile butadiene rubber (JER, PNR-1H product, -COOH: 8% by weight) based on 100 parts by weight of bisphenol A type, and four reactors as epoxy curing agent. 20 parts by weight of 4,4`-diaminodiphenylsulfone (hereinafter referred to as "4,4`-DDS"), 2-ethyl-4-methyl-imidazole as a curing accelerator (hereinafter referred to as "2E4MZ") To prepare an adhesive composition by mixing it was prepared by dissolving it in methyl isobutyl ketone (MIBK).

The urethane resin composition comprises 30 parts by weight of a solution of silane-modified bisphenol A epoxy (Kukdo Chemical, KSR-276) dissolved in 100% by weight of a polyurethane urea resin (Kukdo Chemical, KPU-300) MEK solvent and a phenolic resin (Meiwa). A urethane resin composition was prepared by mixing 10 parts by weight of MEH-7500) and 10 parts by weight of a carboxyl group-containing acrylonitrile butadiene rubber (JER, PNR-1H product, -COOH: 8% by weight).

The acrylic resin composition comprises 100 parts by weight of an epoxy group-containing acrylic resin (SG-P3, Nagase Chemtex, molecular weight 850,000, epoxy group 0.21 eq / kg, solid content 15%) and 70% dissolved in MEK solvent (Kukdo Chemical, KSR). -276) 20 parts by weight of the solution and dicyandiamide (Aldrich, DICY7) was mixed to prepare an adhesive composition.

<Evaluation>

1. Volume resistivity measurement

After cutting the conductive adhesive film containing carbon nanotubes to 3x3cm, roll lamination was performed at a rate of 4 mpm at a metal-based reinforcement (SUS) and at room temperature (25 ° C). Thereafter, the release substrate on the opposite side of the conductive adhesive was removed, and the copper foil laminate film and the punched coverlay film were laminated and subjected to roll lamination at 4 mpm at room temperature, and then the resistance between the metal-based reinforcing material and the copper foil laminate film was measured.

2. Adhesion measurement

After cutting the conductive silicon adhesive film containing carbon nanotubes to 10cm x 10cm, the lamination was carried out at a speed of 4mpm at a metal-based reinforcement (SUS) and room temperature (25 ℃). After removing the release substrate on the opposite side of the conductive silicone pressure-sensitive adhesive, and laminated the copper foil laminate film and the punched coverlay film and roll-lamination at a speed of 4mpm at room temperature (25 ℃) after the copper foil laminate film and coverlay surface 1cm wide Cutting was carried out to measure the adhesive force between the coverlay surface and the metal-based reinforcement.

3. Measurement of solder resistance

After cutting the conductive silicon adhesive film containing carbon nanotubes to 5cm x 5cm, the lamination was carried out at a speed of 4mpm at a metal-based reinforcement (SUS) and room temperature (25 ℃). After removing the release material on the opposite side of the conductive adhesive, laminating the copper foil laminate film and the punched coverlay film and performing a lamination at a speed of 4mpm at room temperature, the resulting specimen was floated on the soldering tank corresponding to each temperature for 10 seconds. After checking whether peeling or bubbles occurred between the coverlay surface and the metal-based reinforcing material was recorded the temperature did not occur. As evaluation conditions, each sample was evaluated within 10 minutes after hot pressing, or after 85 ° C./85%/24 hr constant temperature / humidity treatment to evaluate the soldering heat resistance.

The above evaluation results are summarized in Table 1.

Example [adhesive coating thickness: 40um] Volume resistance
(Ω / cm) adhesiveness
(N / cm) Soldering heat resistance (℃) Within 10 minutes 85 ℃ / 85%
/ 24hr Example 1 Silicone resin, SWNT 0.01wt% 0.5 11 300 280 Example 2 Silicone resin, SWNT 0.05wt% 0.2 11.5 300 280 Example 3 Silicone resin, SWNT 1wt% 0.08 9.8 300 280 Example 4 Silicone resin, MWNT 0.05wt% 0.9 10.5 300 280 Example 5 Silicone resin, MWNT 1wt% 0.5 10.1 300 280 Example 6 Silicone resin, MWNT 2wt% 0.3 8.4 300 280 Comparative Example 1 Silicone resin, silver 0.05wt% 25 8.0 300 280 Comparative Example 2 Silicone resin, silver 1wt% 23 7.6 300 280 Comparative Example 3 Silicone resin, silver 2wt% 16 5.4 300 280 Comparative Example 4 Silicone resin, silver 5wt% 4 3.9 260 230 Comparative Example 5 Silicone resin, silver 8wt% 0.9 2.1 250 210 Comparative Example 6 Epoxy Resin, SWNT 1wt% 0.09 1.1 190 150 Comparative Example 7 Urethane Resin SWNT 1wt% 0.08 0.2 170 140 Comparative Example 8 Acrylic resin SWNT 1wt% 0.09 9.8 220 200

As can be seen in Table 1, in the case of the conductive silicone pressure-sensitive adhesive containing the carbon nanotubes of the present invention, it was confirmed that the volume resistance showed a value of 1 μm / cm or less even with a small amount of 1% of the silver particles. In the case of carbon nanotubes, even a very small amount (0.01 wt%) could secure sufficient conductivity. In addition, since carbon nanotubes have a very small particle size, they can secure excellent adhesion to the substrate. Under the conditions of excellent soldering heat resistance and excellent conductivity (carbon nanotubes of 2 wt% or less and silver particles of 5 wt% or more), metal particles may be formed. It can be seen that the soldering heat resistance is much better than the case.

In case of silicone binder resin, it showed excellent adhesive force (more than 8N / cm) and excellent soldering heat resistance even after roll lamination at room temperature (25 ℃). The heat resistance was very poor. In addition, acrylic resin showed excellent adhesive strength after room temperature lamination, but showed lower heat resistance than silicone resin in soldering heat resistance.

As a result, in order to use the FPCB as a conductive adhesive, it was confirmed that the silicone resin showed superior productivity compared to the thermosetting resin such as epoxy resin and urethane resin, and that the silicone resin was suitable because it had more excellent thermal stability than the acrylic resin.

While the invention has been described in detail with respect to the embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims. .

Thus, the pressure-sensitive adhesive composition for a circuit board of the present invention is used for manufacturing a flexible circuit board (PCB), and the manufactured flexible circuit board is used as a component of a camera and a digital camera of a mobile phone.

Claims (8)

Iii) diorganopolysiloxanes at both ends of the molecule capped with alkenyl groups (viscosities of at least 5 × 10 ⁵ cP); Ii) organopolysiloxane resins consisting of R ₃ SiO _1/2 units, wherein R is an alkyl, alkenyl or hydroxyl group; and SiO _4/2 units; Iii) organopolysiloxane having at least two silicon-bonded hydrogen atoms in one molecule, which has from 1 to 20 silicon-bonded hydrogen atoms per one alkenyl group of component diorganopolysiloxane; And iii) an organic solvent; based on 100 parts by weight of the silicone pressure sensitive adhesive composition comprising;
5 to 50 parts by weight of a silicone resin, which is a polydialkylsiloxane having a structure represented by Formula 1; And
[Chemical Formula 1]

Wherein R is a methyl or phenyl group
Conductive silicone pressure-sensitive adhesive composition comprising 0.01 to 2 parts by weight of carbon nanotubes. delete delete The conductive silicone pressure-sensitive adhesive composition of claim 1, wherein the carbon nanotubes have an average length of 0.01 to 20 µm. A conductive adhesive film coated with a conductive silicone pressure-sensitive adhesive composition of claim 1 on a release substrate. The conductive adhesive film according to claim 5, wherein the coating thickness of the conductive silicone adhesive composition is 10 to 100 µm. A circuit board in which a circuit board main body and a circuit part are adhered and electrically connected by the conductive adhesive composition layer of claim 1 comprising carbon nanotubes having an average length of 0.01 to 20 μm. 8. The circuit board according to claim 7, wherein the circuit component is a metal reinforcing plate.