KR20190019579A - Polyimide based adhesive composition, bonding sheet comprising the same, and method for manufacturing bonding sheet using the same - Google Patents

Abstract

Provided is a polyimide-based adhesive composition comprising a polyimide-based resin and an inorganic filler. By comprising the polyimide-based adhesive composition, it is possible to manufacture the polyimide-based adhesive composition having high insulation resistance and low dielectric properties, and a bonding sheet comprising the same.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide-based adhesive composition, a bonding sheet containing the same, and a method for manufacturing a bonding sheet using the same. BACKGROUND ART < RTI ID = 0.0 >

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide-based adhesive composition having a high insulation resistance, a bonding sheet comprising the same, and a method of manufacturing a bonding sheet using the same. More specifically, the present invention relates to a polyimide- A polyimide-based adhesive composition having dielectric properties, a bonding sheet comprising the same, and a method of manufacturing a bonding sheet using the same.

BACKGROUND OF THE INVENTION [0002] Flexible printed circuit boards (FPCBs) have recently been adopted as core substrates for electronic equipment due to weight reduction, miniaturization, and high density of electronic equipment products using printed circuit boards (PCB).

The flexible circuit board is advantageous for miniaturization and weight reduction of a device because the flexible circuit board is thin and easy to bend because it uses a laminated plate made by attaching a metal foil to the surface of a flexible insulating film as a base,

The flexible circuit board can be composed of a single layer, a multilayer such as a two-layer or a three-layer, and the use of a multi-layer flexible circuit board is further increasing as the structure and function of an electronic device are diversified.

Particularly, as the demand for high integration, high miniaturization, high performance, and the like in current PCB field is increasing, the situation is gradually changing to integrate electronic devices, increase density of printed circuit boards and simplify wiring intervals. In order to satisfy such a characteristic, it is preferable to use a low dielectric constant for increasing the transmission speed and a low dielectric loss material for reducing the transmission loss.

In addition, due to the high integration and high density of the PCB pattern, free ions existing in the insulator are activated by moisture or chlorine absorbed between the circuit and the insulator. As a result, metal ionization occurs at the anode, and metal ions are reduced at the cathode. As a result, the metal gradually grows into a dendrite, causing a short, etc., resulting in a serious problem of reliability of the product. In the case of the epoxy resin used in the prior art, although the technique of reducing chlorine is improved, the line width becomes finer and the epoxy resin is limited.

Japanese Laid-Open Patent Application No. 2014-0118228

The present invention relates to a polyimide adhesive bonding sheet which exhibits low dielectric properties and ion migration characteristics including a polyimide resin and an inorganic filler and which satisfies adhesion, heat resistance and resin flow required in FPCB production, and a polyimide adhesive To provide a flexible copper clad laminate (FCCL).

In exemplary embodiments of the present invention, 10 to 70% by weight, based on the total weight of the polyimide-based adhesive composition, of a polyimide-based resin; 0.1 to 20% by weight of a crosslinking agent; And 10 to 60% by weight of an inorganic filler.

In exemplary embodiments of the present invention, there is provided a bonding sheet comprising the above-described polyimide-based adhesive composition.

In exemplary embodiments of the present invention, a release film; An adhesive layer formed on the release film and comprising the above-described polyimide-based adhesive composition, wherein the polyimide-based adhesive composition is cured; And a releasing sheet formed on the adhesive layer.

In exemplary embodiments of the present invention, the above-described polyimide-based adhesive layer; And at least one polyimide film or a copper foil formed on both sides of the adhesive layer (FCCL; Flexible Copper Clad Laminate).

In exemplary embodiments of the present invention, there is provided a method comprising: preparing a release film; Forming an adhesive layer using the above-described polyimide-based adhesive composition; And forming a release paper on the adhesive layer.

In exemplary embodiments of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: peeling a release film and a release sheet of a bonding sheet manufactured according to the above-described method; And bonding at least one copper foil or polyimide film to both sides of the peeled bonding sheet. The present invention also provides a method of manufacturing a flexible copper clad laminate (FCCL).

According to exemplary embodiments of the present invention, the polyimide-based adhesive composition may include a polyimide-based resin to provide a bonding sheet having low dielectric properties and adhesion.

In addition, the polyimide-based adhesive composition contains an inorganic filler in a specific amount to lower the coefficient of thermal expansion (CTE) of the dielectric, thereby reducing the defective ratio in manufacturing a printed circuit board (PCB) , A bonding sheet excellent in heat resistance can be produced.

In addition, the above-mentioned bonding sheet can provide a flexible copper-clad laminate having high heat resistance and mechanical properties, but not deteriorating adhesiveness and having excellent mechanical properties, by including the polyimide-based adhesive composition.

1 is a bonding sheet according to an embodiment of the present invention.
2 is a flexible copper clad laminate (FCCL) according to an embodiment of the present invention.

Term Definition

As used herein, the term " bonding sheet " refers to a sheet having a release film, a release sheet, and an adhesive layer, which can be suitably used for bonding electronic devices, particularly semiconductor packaging, COL, LOC, MCM, FPC, Quot; multilayer sheet "

As used herein, the term " adhesive " refers to a component that does not change its component unless it is artificially moved by attaching two or more products having completely different physical properties, and has a viscoelastic property capable of strongly adhering to even a small pressure for a short time Material. The adhesive can be used for general industrial tapes or electronic materials, and can be used when attaching an optical film to a display panel such as a liquid crystal cell and an organic EL panel, or to a front face plate.

In particular, in the present invention, a " polyimide-based adhesive composition " containing the above adhesive may be coated on a release-coated film and used to increase the adhesive strength when stacking a PCB.

As used herein, the term "inorganic filler" refers to a group of particles including inorganic elements such as silicon and alumina. The "average particle diameter" of the inorganic filler means an average value of the diameters of the single particles. Herein, the average particle diameter range of the inorganic filler means that not less than 95% of the inorganic filler present in the composition falls within the above range.

Illustrative Implementations  Explanation

Hereinafter, exemplary embodiments of the present invention will be described in detail.

In exemplary embodiments of the present invention, the polyimide-based adhesive composition comprises 10 to 70% by weight, based on the total weight of the polyimide-based adhesive composition, of a polyimide-based resin; 0.1 to 20% by weight of a crosslinking agent; And 10 to 60% by weight of an inorganic filler.

The influence of water and impurities (chlorine) on the growth factor of ion migration for confirming the insulation performance of the flexible circuit board is great. In particular, in the case of an epoxy adhesive, the ion migration performance is deteriorated due to the influence of impurities (chlorine). Therefore, the present invention improves the insulating property by including a polyimide resin which is free of impurities (chlorine) instead of epoxy.

The component of the polyimide resin may preferably be an aromatic tetracarboxylic acid anhydride component. As long as the polyimide-based resin is a monomeric group-containing reaction product containing an aromatic diamine component, various known ones can be used without particular limitation. Examples of the anhydride component include pyromellitic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3', 4,4'- Diphenyl ether tetracarboxylic acid dianhydride, 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 1,2,3,4-benzenetetracarboxylic acid dianhydride, 1,4, Naphthalene tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenonetetracarboxylic acid Acid dianhydride, 2,3,3 ', 4'-diphenyl ether tetracarboxylic dianhydride, 2,3,3', 4'-diphenylsulfone tetracarboxylic acid dianhydride, 2,2-bis ( 3,3 ', 4,4'-tetracarboxyphenyl) tetrafluoropropane dianhydride, 2,2'-bis (3,4-dicarboxyphenoxyphenyl (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride and 4,4 '[propane- , 2-diylbis (1,4-phenyleneoxy)] diphthalic acid dianhydride, and the like, and preferably two or more of them can be combined.

The aromatic diamines include aromatic diamines such as phenylenediamine (PDA), oxydianiline (ODA), o-phenylenediamine (OPD), metaphenylene diamine (MPD) 4-aminophenoxy) benzene (TPER, 1,3-bis (4-aminophenoxy) benzene), 4,4'- ) benzene, 2,2'-dimethyl-4,4'-diaminobiphenyl (TFDB, 2,2'-Dimethyl-4,4'-diaminobiphenyl Bis (trifluoromethyl) benzidine, 1,3'-bis (3-aminophenoxy) benzene (APBN, 1,3'-Bis (3-aminophenoxy) benzene ), 3,5-diaminobenzotrifluoride (DABTF), and 2,2-bis (4- [4- aminophenoxy] -phenyl) propane (BAPP, 2,2-bis 4- [4-aminophenoxy] -phenyl) propane).

The polyimide-based resin is contained in an amount of 10 to 70 wt% based on the total weight of the polyimide-based adhesive composition. When the polyimide-based resin is added in an amount of 10 wt% or more, low- , Adhesion and heat resistance may be deteriorated.

The crosslinking agent may be, for example, a polyphenylene ether compound, a polyepoxy compound, but is not limited thereto. In the case of a polyepoxy compound, a phenol novolak type epoxy compound, a cresol novolak type epoxy compound, a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, Hydrogenated bisphenol A type epoxy compounds, hydrogenated bisphenol F type epoxy compounds, stilbene type epoxy compounds, triazine skeleton containing epoxy compounds, fluorene skeleton containing epoxy compounds, linear aliphatic epoxy compounds, alicyclic epoxy compounds, glycidylamine type epoxy compounds , Triphenol methane type epoxy compounds, alkyl modified triphenolmethane type epoxy compounds, biphenyl type epoxy compounds, dicyclopentadiene skeleton containing epoxy compounds, naphthalene skeleton containing epoxy compounds, aryl alkylene type epoxy compounds, tetraglycidyl xylylenediamine , These The epoxy compound can be mentioned the modified epoxy compound modified from dimer acid, dimer acid, such as di-glycidyl ester, and may preferably be combined to have two or more of them.

Especially, an epoxy crosslinking agent can be preferably used in order to control the general polyimide resin in consideration of the moisture content of 2%.

When the content of the crosslinking agent is less than 0.1% by weight, the crosslinking density and adhesive cohesion are weakened and the crosslinking agent is not effective. When the content of the crosslinking agent is less than 20% by weight The heat resistance may be lowered due to the influence of unreacted monomers.

The inorganic filler reduces the coefficient of thermal expansion (CTE) value of the dielectric material. By including the inorganic filler, it is possible to reduce the defective rate when manufacturing a printed circuit board (PCB) and manufacture a bonding sheet having excellent heat resistance can do.

Generally, failure of an electronic device is a strain caused by a difference in the coefficient of thermal expansion (CTE). Copper Clad Laminate (CCL) materials are used to assemble printed circuit boards (PCBs). These copper clad laminates are made by bonding resin to Cu foil. In order to reduce the defect rate, the CTE value of the raw material is required in order to reduce the defective rate because the CTE of the adhesive resin differs more than 10 times from that of the metal generally when bonding the copper-clad laminate to the bonding sheet. As a result, the low thermal expansion coefficient of the adhesive composition has an effect of reducing defects in the manufacture of PCBs.

In addition, when the thermal expansion coefficient is high, there is a problem that the bonding sheet surface can not withstand the heat or gas generated during the hole drilling process for the conduction of the double-sided metal surface during the manufacture of the double-sided FPCB. Accordingly, the polyimide-based adhesive composition according to the present invention has a feature that the bonding sheet can withstand a hole drilling process because the bonding sheet has a low thermal expansion coefficient when assembling a printed circuit board (PCB).

Further, by including the inorganic filler, it is possible to form fine protrusions on the surface of the adhesive layer and improve the adhesiveness of the bonding sheet.

In an exemplary embodiment, the inorganic filler may be at least one selected from the group consisting of silica, alumina, magnesium oxide, talc, titanium oxide, boron nitride, zirconia, calcium carbonate, magnesium carbonate, and aluminum hydroxide.

The inorganic filler may preferably be silica, and more preferably it may be spherical silica. When the inorganic filler is spherical silica, it is possible to control moisture absorption, so that insulation resistance can be improved.

Generally, due to the influence of the moisture absorbed in the insulator, the free ions of the insulator are activated to activate the ionization of the metal, and the metals gradually grow, resulting in a dendrite phenomenon and a short.

Therefore, in the case of an insulator, the square type silica generally has a large specific surface area, so that the moisture absorption is large, but the spherical shape has a small specific surface area relative to the square shape, so that moisture absorption is low and insulation resistance is high.

The inorganic filler is contained in an amount of 10 to 60% by weight based on the total weight of the polyimide-based adhesive composition. When the content is less than 10% by weight, the CTE value is high and the resin flow can be increased. , It is difficult to uniformly disperse the inorganic filler in the adhesive and the homogeneity of the adhesive layer may be impaired and the viscosity may become excessively high and the workability may be deteriorated.

The inorganic filler may have an average particle diameter of 1 to 10 mu m, and when the particle diameter is less than 1 mu m, it may be difficult to form fine protrusions for improving the adhesiveness of the bonding sheet. If the particle diameter is more than 10 mu m, Damage to the mid-film or copper foil can cause physical damage.

In an exemplary embodiment, the polyimide-based adhesive composition may further comprise a solvent. Examples of the solvent include aprotic polar solvents such as N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N-methylcaprolactam, methyltriglyme and methyldiglime; Aliphatic cyclic solvents such as cyclohexanone and methylcyclohexane; And alcohol solvents such as methanol, ethanol, propanol, benzyl alcohol and cresol, and aromatic solvents such as toluene. These solvents may be used alone or in combination of two or more.

The polyimide-based adhesive composition may further include a curing agent. The curing agent may be selected from the group consisting of 1,6-hexanediol diacrylate, dipentaerythritol hexaacrylate, Acrylates such as tetramethylolmethane tetraacrylate, tetramethylolmethane triacrylate, trimethylolpropane triacrylate, 1,6-bis (3-acryloyloxy-2-hydroxypropyl) 3-acryloyloxy-2-hydroxypropyl) hexane], polyethylene glycol diacrylate, pentaerythritol triacrylate, and hexamethylene diisocyanate urethane And a prepolymer (hexamethylene diisocyanate urethane prepolymer).

The polyimide adhesive composition of the present invention may contain at least one member selected from the group consisting of a ring opening esterification catalyst, a dehydrating agent, a plasticizer, a lubricant, a lubricant, an antistatic agent, a bleaching agent, a colorant, An additive such as a modifier, a phosphorus flame retardant, a flame retardant filler, a silica filler, and a fluorine filler.

In exemplary embodiments of the present invention, there is provided an adhesive layer comprising the above-described polyimide-based adhesive composition, wherein the polyimide-based adhesive composition is cured.

In exemplary embodiments of the present invention, a release film; The above-mentioned adhesive layer; And a releasing sheet formed on the adhesive layer.

The release film can be used without limitation as long as it is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like. For example, it may be a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate and the like, preferably a polyester film.

The thickness of the release film may be from 12 to 75 탆. If the thickness is less than 12 탆, the film is thin and the smoothness and workability are difficult. If the thickness exceeds 75 탆, the cost increases.

When the thickness of the adhesive layer is less than 1 占 퐉, the thickness of the adhesive layer may be as small as 1 to 75 占 퐉. Therefore, there is a problem that when the adhesive layer is adhered to a copper foil or a polyimide film, If it exceeds, it becomes a factor of cost increase.

The release paper can be used without limitation as long as it has excellent heat resistance because wrinkles may occur on the copper foil when the release paper is weak to heat in the manufacturing process described later. Preferably, the polypropylene resin is coated on paper, It may be silicon coated. In the case of a general polyethylene coating layer, since there is a problem that the release paper is wrinkled at a high ramie temperature, it is preferable to coat it with a polypropylene resin having excellent heat resistance at a high ramie temperature in a printed circuit board process.

The thickness of the release paper may be 90 탆 to 140 탆. When the thickness is less than 90 탆, the heat-labile paper can not withstand heat, resulting in poor workability.

In an exemplary embodiment, the insulation resistance of the bonding sheet may be 10 ⁶ Ω or more, the dielectric constant may be 3 or less, and the adhesion may be 900 gf / cm or more. The resin flow may also be less than 100 탆.

In exemplary embodiments of the present invention, the above-mentioned adhesive layer; And at least one polyimide film or a copper foil formed on both sides of the adhesive layer (FCCL; Flexible Copper Clad Laminate).

Since the flexible copper-clad laminate includes the above-described adhesive layer, it exhibits low dielectric properties and excellent adhesion heat resistance.

In exemplary embodiments of the present invention, there is provided a method comprising: preparing a release film; Forming an adhesive layer using the above-described polyimide-based adhesive composition; And forming a release paper on the adhesive layer. The release film may be formed by coating a base film with a silicone resin or the like.

The adhesive layer may be formed by applying one or more coating processes such as gravure coating, microgravure coating, spin coating, screen printing, comma coating, die coating, Base) coated on a polyester film), dried, and then heat-treated to form a cured film.

In general silicon coating, the leveling property of the silicon coating surface is not good, and the surface is insufficient, and there is a possibility that defects such as some residual silicon are generated. Accordingly, by coating with the modified silicone of acrylic base, it is possible to manufacture a bonding sheet having a coating surface excellent in releasing peel force with a low value as in the case of silicone coating.

At the time of application, known methods such as a bar coating method, a doctor blade method, a reverse roll coating method, and a gravure roll coating method can be used. Further, the release film may be dried or cured such as thermal curing or ultraviolet curing, either individually or simultaneously.

Thereafter, a release sheet is laminated on the adhesive layer by a thermocompression bonding method to produce a bonding sheet.

In an exemplary embodiment of the present invention, the step of peeling the release film and the release paper of the bonding sheet obtained as described above; And bonding at least one copper foil or polyimide film to both sides of the peeled bonding sheet. The present invention also provides a method of manufacturing a flexible copper clad laminate (FCCL).

The bonding sheet can be used for various purposes. The bonding sheet may be a laminated board obtained by laminating, for example, a copper foil or a polyimide film on both sides thereof.

The manufacturing method of the flexible copper-clad laminate is not particularly limited. A method in which a copper foil or a polyimide film is superimposed on the adhesive layer on both sides of a peeled bonding sheet and sandwiched between two small-diameter cylinders and pressed in a short time; a method of thermocompression bonding a bonding sheet and a copper foil in a vacuum state using a vacuum forming press ; And a method of continuously thermocompression bonding, and the like, but are not limited thereto.

Preferably, a continuous thermocompression method can be used, and the continuous thermocompression method can be a method of continuously heating and pressing at a specific point, and a method of continuously heating and pressurizing. According to the continuous thermocompression bonding method, the bonding sheet having the adhesive layer and the copper foil or the polyimide film are adhered without air or wrinkles regardless of the kind of the adhesive.

In an exemplary embodiment, the release film and the release paper of the bonding sheet are peeled off, the adhesive layer is adhered to the polyimide film or the copper foil surface and laminated, and the laminated sample is pressed through a hot press process Products can be manufactured.

The hot pressing may be performed at a temperature of 150 to 180 DEG C for about 30 minutes to 2 hours or more and about 20 to 45 kg of a surface pressure.

Hereinafter, specific embodiments according to exemplary embodiments of the present invention will be described in more detail. It should be understood, however, that the invention is not limited to the embodiments described below, but that various embodiments of the invention may be practiced within the scope of the appended claims, It will be understood that the invention is intended to facilitate the practice of the invention to those skilled in the art.

Example - Preparation of polyimide-based adhesive composition

1-1. Preparation of polyimide-based adhesive composition: By content, Filler  By type

An adhesive composition was prepared according to the composition shown in Table 1 below.

Example  One Example  2 Example  3 Example  4 Example  5 Example  6 Example  7 Example  8 Example  9 Polyimide resin (benzophenone tetracarboxylic dianhydride / phenylenediamine (PDA) synthesized at a ratio of 40% / 60%) 60 wt% 60 wt% 60 wt% 60 wt% 70 wt% 60 wt% 50 wt% 40 wt% 30 wt% Inorganic filler Spherical silica,
30 wt% Flaky silica,
30 wt% Aluminum hydroxide,
30 wt% Alumina,
30 wt% Spherical silica, 20 wt% Spherical silica, 30 wt% Spherical silica, 40 wt% Spherical silica, 50 wt% Spherical silica, 60 wt% Crosslinking agent (bisphenol A type epoxy compound) 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% Hardener (hexamethylene diisocyanate urethane pre-polymer) 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% Coupling agent (N- (2-aminoethyl) -3-aminopropyltrimethoxysilane) 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% Solvent (cyclohexanone / toluene mixed at 75% / 25% ratio) Up to 100 Up to 100 Up to 100 Up to 100 Up to 100 Up to 100 Up to 100 Up to 100 Up to 100

1-2. Adhesive composition manufacturing: Weapons Filler By size

An adhesive composition was prepared according to the composition shown in Table 2 below.

Example  10 Example  11 Example  12 Example  13 Example  14 Polyimide resin (benzophenone tetracarboxylic dianhydride / phenylenediamine (PDA) synthesized at a ratio of 40% / 60%) 60 wt% 60 wt% 60 wt% 60 wt% 60 wt% Inorganic filler Spherical silica,
30 weight, size 0.3 탆 Spherical silica,
30% by weight, size 0.7 탆 Spherical silica,
30 wt%, size 1 mu m Spherical silica,
30% by weight, size 3 탆 Spherical silica,
30% by weight, size 10 탆 Crosslinking agent (bisphenol A type epoxy compound) 5 wt% 5 wt% 5 wt% 5 wt% 5 wt% Hardener (hexamethylene diisocyanate urethane pre-polymer) 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% 1.7 wt% Coupling agent (N- (2-aminoethyl) -3-aminopropyltrimethoxysilane) 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% 3.3 wt% Solvent (cyclohexanone / toluene mixed at 75% / 25% ratio) Up to 100 Up to 100 Up to 100 Up to 100 Up to 100

Comparative Example  - Adhesive composition manufacturing

An adhesive composition was prepared according to the composition shown in Table 3 below.

Comparative Example  One Comparative Example  2 Resin type Bisphenol A,
68 wt% Glycidyl methacrylate,
65 wt% Inorganic filler Aluminum hydroxide (Al ₂ O ₃ ), 20 wt% Spherical silica (SiO _2),
30 wt% Cross-linking agent Diphenylene diisocyanate / dicyandiamide was mixed in a ratio of 0.8 / 1.2,
2 wt% Isocyanate,
5 wt% solvent DMF / toluene was mixed at 55% / 45%, Up to 100 DMF, Up to 100 Other additives Diphenyl monooctyl phosphate (DPMOP), 10 wt%
-

Experimental Example  One - Migration of ions  evaluation

Bonding sheets were prepared using the adhesive compositions of Examples 1 to 4 and Comparative Examples 1 and 2, and the ion migration evaluation was carried out.

Specifically, the adhesive compositions of Examples 1 to 4 and Comparative Examples 1 and 2 were prepared and coated on a release film (a polyester film coated with a modified silicone (acrylic base)) by a comma coating method. The coating thickness was set to 25 μm and the solvent was dried at 150 ° C. for 2 minutes. Then, the cured resin was peeled from the release film to prepare a bonding sheet.

The test specimens were prepared by laminating 25μm of 25μm / PI film with 2-layer FCCL / bonding sheet. The specimens were tested with Ion migration evaluation system: AMI-025-U-5 (ESPEC Corp., Japan). The experimental conditions were as follows. The test was carried out under the conditions of 85 占 폚 / 85% RH / 50V DC / 500 hr with a line width of 50 占 퐉 / pattern width of 50 占 퐉 of the two-layer FCCL and the results are shown in Table 4 below.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Insulation Resistance (Ω) 10 ⁹ 10 ⁷ 10 ⁶ 10 ⁶ 10 ⁵ 10 ⁵ Dendrite Yes / No radish radish radish radish U U

Compared with the polyimide adhesives (Examples 1 to 4) and the epoxy adhesive (Comparative Example 1), the polyimide adhesive had good dendrite, but in the case of the epoxy adhesive, dendrite occurred between the circuit and the circuit And became a short. In addition, the insulation characteristics should be at least 10 ⁶ in spec. The comparison of the types of polyimide resin + inorganic filler showed that the spherical silica filler was the best at 10 ⁹ , and the remaining inorganic filler was 10 ⁷ or 10 ⁶ , 1 and 2, respectively.

Experimental Example  2 - dielectric constant evaluation

The permittivity test was performed by coating a release film (polyester film coated with modified silicone (acrylic base)) with the polyimide-based adhesive composition according to Examples 5 to 9, drying and curing at 170 占 폚 for 1 hour. Then, a hardened adhesive layer is laminated to make a specimen having a thickness of 800 μm or more. Data were measured using a dielectric constant measuring device. In order to improve the dielectric constant, the content and size (size) of the inorganic filler filler were blended to confirm the characteristics. The results are shown in Tables 5 and 6 below.

(1) Weapons Filler  Permittivity by content

division Example  5 Example  6 Example  7 Example  8 Example  9 The dielectric constant (Dk) 2.8 2.8 2.8 2.9 3.0 Dielectric tangent (Df) 0.004 0.004 0.005 0.006 0.006

As a result of the evaluation of the dielectric constant, it was confirmed that the dielectric constant and dielectric loss tangent of the polyimide adhesive composition were very good (standard 3.0 or less). When the content of the inorganic filler was increased, the content of the polyimide adhesive having low dielectric properties was lowered, And that it could be worse.

(2) Weapons Filler  Permittivity by size

division Example  10 Example  11 Example  12 Example  13 Example  14 The dielectric constant (Dk) 2.5 2.6 2.8 2.8 2.8 Dielectric tangent (Df) 0.003 0.003 0.006 0.006 0.006

As a result of measuring the permittivity according to the filler size, it was possible to confirm the low dielectric properties as the size was small. However, if the size is small, the specific surface area increases and there is a possibility that the dispersion may not be achieved during the agitation of the adhesive. When the size is large, the dispersibility is good, but since the dielectric constant can be high, it is important to select a size range (1 to 10 mu m) in which dispersion is possible.

Experimental Example  3 - Evaluation of physical properties (heat resistance and adhesion, Resin flow )

<Reliability test>

In order to proceed with the evaluation of the physical properties of the bonding sheet, heat resistance, adhesion, and resin flow were measured. First, the releasing film of the releasing film / adhesive composition (Examples 6 and 7, Comparative Examples 1 and 2) / releasing paper specification bonding sheet was peeled off, and a polyimide adhesive surface was attached to one surface of the polyimide film to conduct thermal lamination . Next, the releasing paper was peeled off, and a copper foil was attached to the surface of the polyimide adhesive to conduct thermal lamination. The hot lamination was conducted under a condition of 120 DEG C for 5 seconds using a general heat laminator.

When the test specimen composed of the polyimide film / polyimide adhesive / copper foil is completed, the hot press lamination test is performed under the temperature condition of 150 to 180 ° C. for about 30 minutes to 2 hours and the surface pressure of about 20 to 45 kg do. Heat resistance, adhesion, and resin flow properties were confirmed with the laminated sample.

division Condition Comparative Example 1 Comparative Example 2 Example 6 Example 7 Heat resistance 288 ° C, 10 sec
Visual confirmation OK NG OK OK Adhesion
(gf / cm) Room temperature 650 700 1000 900 Resin flow
(um) Room temperature <100 200 <100 <100

As a result of the reliability test, the heat resistance of Comparative Example 1, Examples 6 and 7 was good at 288 占 폚 without lifting or breaking, and the adhesion was excellent at 900 gf / cm or more in Examples 6 and 7. In the case of resin flow, Comparative Example 2 was insufficient at 200 μm, but Comparative Example 1, Examples 6 and 7 were less than 100 μm.

100: release paper
110: adhesive layer
120: release film
130: copper plate
140: polyimide film

Claims (15)

Based on the total weight of the polyimide-based adhesive composition,
10 to 70% by weight of a polyimide resin;
0.1 to 20% by weight of a crosslinking agent; And
10 to 60% by weight of an inorganic filler.
The method according to claim 1,
Wherein the inorganic filler has an average particle diameter of 1 to 10 占 퐉.
The method according to claim 1,
Wherein the inorganic filler is at least one selected from the group consisting of silica, alumina, magnesium oxide, talc, titanium oxide, boron nitride, zirconia, calcium carbonate, magnesium carbonate, and aluminum hydroxide.
The method according to claim 1,
Wherein the inorganic filler is silica and is spherical.
The method according to claim 1,
Wherein the polyimide-based adhesive composition further comprises a solvent.
An adhesive layer comprising the polyimide-based adhesive composition according to any one of claims 1 to 5, wherein the polyimide-based adhesive composition is cured.
Release film;
An adhesive layer formed on the release film and comprising the polyimide-based adhesive composition according to any one of claims 1 to 5, wherein the polyimide-based adhesive composition is cured; And
And a releasing sheet formed on the adhesive layer.
8. The method of claim 7,
Wherein the thickness of the adhesive layer is 1 to 75 mu m.
8. The method of claim 7,
Wherein the adhesive layer has an insulation resistance of 10 ⁶ Ω or more.
8. The method of claim 7,
Wherein the adhesive layer has a dielectric constant of 3 or less.
8. The method of claim 7,
Wherein an adhesive strength of the adhesive layer is 900 gf / cm or more.
8. The method of claim 7,
Wherein the adhesive layer has a resin flow of 100 m or less.
An adhesive layer comprising the polyimide-based adhesive composition according to any one of claims 1 to 5, wherein the polyimide-based adhesive composition is cured; And
(FCCL) comprising at least one polyimide film or a copper foil formed on both sides of the adhesive layer.
Preparing a release film;
Forming an adhesive layer on the release film using the polyimide-based adhesive composition according to any one of claims 1 to 5; And
And forming a release paper on the adhesive layer.
Peeling the release film and the release paper of the bonding sheet produced according to claim 14;
And bonding at least one copper foil or a polyimide film to both sides of the peeled bonding sheet. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;

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