KR102259099B1 - Bonding film, bonding film laminate comprising the same and metal clad laminate comprising the same - Google Patents

Abstract

The present invention relates to an adhesive film formed of a composition including a binder resin, an epoxy resin, and a filler. More specifically, provided are: the adhesive film which has a minimum melt viscosity of 30,000 to 60,000 Pa.s after curing, wherein the adhesive film is 85°C after curing, has 85% relative humidity, and has 1 x 10^12 Ω or more of the ion movement when a voltage of 50 V is applied under 500 hours; an adhesive film-attached laminate including the same; and a metal foil laminate including the same.

Description

Adhesive film, a laminate with an adhesive film including the same, and a metal foil laminate including the same {BONDING FILM, BONDING FILM LAMINATE COMPRISING THE SAME AND METAL CLAD LAMINATE COMPRISING THE SAME}

The present invention relates to an adhesive film, a laminate with an adhesive film including the same, and a metal foil laminate including the same. More specifically, the present invention has a low dielectric constant and dielectric loss over a wide range of temperatures and frequencies, and has a minimum melt viscosity in a specific range, thereby increasing adhesion and without ion migration. It relates to a laminate with an adhesive film including the same and a metal foil laminate including the same.

Recently, with the trend of integration, miniaturization, thin film, high density, and high bending of electronic products, the need for a printed circuit board (PCB), which can be easily embedded in a narrow space, has increased. In particular, recently, a flexible printed circuit board (FPCB) having repetitive flexibility has been developed. The demand for flexible printed circuit boards is increasing due to the rapid increase in use due to technological developments such as smart phones and portable mobile electronic devices.

Generally, in a flexible circuit board, copper foil as a metal foil is laminated|stacked on the base film comprised by polyimide resin etc. as a base film. The base film and the metal foil are adhered to each other by an adhesive film. Conventionally, the adhesive film was formed of a polyimide-based adhesive, an acrylonitrile-butadiene rubber-based adhesive, or the like. However, polyimide-based adhesives, acrylonitrile-butadiene rubber-based adhesives, and the like have limitations in lowering the dielectric constant and moisture absorption.

Background art of the present invention is disclosed in Korean Patent Publication No. 2016-0083204 and the like.

An object of the present invention is to provide an adhesive film having a low dielectric constant and a low dielectric loss.

Another object of the present invention is to provide an adhesive film having a minimum melt viscosity within a specific range.

Another object of the present invention is to provide an adhesive film having a low resistance and securing an appropriate range for ion migration.

Another object of the present invention is to provide an adhesive film having a low rate of change of dielectric constant and dielectric loss according to frequency change.

Another object of the present invention is to provide an adhesive film having a low rate of change of dielectric constant and dielectric loss according to temperature change.

Another object of the present invention is to provide an adhesive film having excellent adhesion and heat resistance.

Another object of the present invention is to provide an adhesive film having excellent flexibility at room temperature and high temperature, and low elasticity modulus ratio between room temperature and high temperature, and thus having excellent reliability of flexibility between room temperature and high temperature.

Another object of the present invention is to provide a laminate with an adhesive film and a metal foil laminate comprising the adhesive film of the present invention.

One aspect of the present invention is an adhesive film.

1. The adhesive film is formed of a composition including a binder resin, an epoxy resin and a filler, the adhesive film has a minimum melt viscosity of 30,000 Pa.s to 60,000 Pa.s after curing, and the adhesive film is at 85° C. after curing, When a voltage of 50V is applied under 85% relative humidity and 500 hours, the ion movement is 1 x 10 ¹² Ω or more.

In 2.1, the adhesive film has a dielectric constant of 2.5 or less, a dielectric loss (Df) of 0.004 or less, measured at 1 GHz to 10 GHz and 20 ° C to 80 ° C after curing, and the adhesive film has a moisture absorption rate of 0.1 after curing % or less.

In 3.1-2, the composition may not include a curing agent.

In 4.1-3, the ratio of the total number of moles of carboxylic acid groups in the binder resin to the total number of moles of epoxy groups in the epoxy resin ([Total moles of carboxylic acid groups in the binder resin]/[Total moles of epoxy groups in the epoxy resin]) It may be 1 to 2.

In 5.1-4, the binder resin may include a carboxylic acid-modified olefin-based resin and a polyphenylene ether-based resin.

In 6.5, the carboxylic acid-modified olefin-based resin may include an olefin-based resin modified by at least one of acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric anhydride. .

In 7.5, among 100 parts by weight of the total binder resin, the carboxylic acid-modified olefin-based resin may be included in an amount of 50 to 95 parts by weight, and the polyphenylene ether-based resin may be included in an amount of 5 to 50 parts by weight.

In 8.5, the binder resin may further include a carboxylic acid-modified styrene-based elastomer.

In 9.8, among 100 parts by weight of the total binder resin, the carboxylic acid-modified olefin-based resin is 50 parts by weight to 85 parts by weight, the polyphenylene ether-based resin is 5 to 30 parts by weight, and 1 weight of the carboxylic acid-modified styrene-based elastomer It may be included in parts to 20 parts by weight.

In 10.5, the carboxylic acid-modified olefin-based resin may include a carboxylic acid-modified linear polypropylene-based resin.

In 11.1-10, the filler may include a mixture of inorganic nano silica and a fluororesin filler.

In 12.11, the fluororesin filler may be included in an amount of 100 parts by weight to 800 parts by weight based on 100 parts by weight of the inorganic nano silica.

In 13.1-12, with respect to 100 parts by weight of the binder resin, 3 parts by weight to 18 parts by weight of the epoxy resin and 1 part by weight to 50 parts by weight of the filler may be included.

A laminate with an adhesive film of the present invention includes a polyimide-based resin film and the adhesive film of the present invention provided on at least one surface of the polyimide-based resin film.

The metal foil laminate of the present invention includes a polyimide-based resin film, an adhesive film provided on at least one surface of the polyimide-based resin film, and a metal foil provided on one surface of the adhesive film, wherein the adhesive film is the polyimide-based resin film. It is provided between the resin film and the metal foil, and the adhesive film includes the adhesive film of the present invention.

The present invention provides an adhesive film having a low dielectric constant and low dielectric loss.

The present invention provides an adhesive film having a minimum melt viscosity in a specific range.

The present invention provides an adhesive film having low resistance and securing an appropriate range for ion migration.

The present invention provides an adhesive film having a low rate of change of dielectric constant and dielectric loss according to frequency change.

The present invention provides an adhesive film having a low rate of change of dielectric constant and dielectric loss according to temperature change.

The present invention provides an adhesive film excellent in adhesive strength and heat resistance.

The present invention provides an adhesive film having excellent flexibility at room temperature and high temperature and having excellent reliability of flexibility between room temperature and high temperature due to a low ratio of elastic modulus between room temperature and high temperature.

The present invention provided a laminate with an adhesive film and a metal foil laminate comprising the adhesive film of the present invention.

1 is a cross-sectional view of a laminate with an adhesive film according to an embodiment of the present invention.
2 is a cross-sectional view of a metal foil laminate according to an embodiment of the present invention.
3 shows the dielectric constant and dielectric loss according to the frequency change of the adhesive films of Example 1, Comparative Example 1, and Comparative Example 2. In FIG. 3, △ indicates Example 1, ◇ indicates Comparative Example 1, and □ indicates the result of Comparative Example 2.
4 shows the dielectric constant and dielectric loss according to the temperature change of the adhesive films of Example 1 and Comparative Example 2. FIG. In FIG. 4, ○ indicates the result of Example 1, and □ indicates the result of Comparative Example 2.

The present invention will be described in detail so that those skilled in the art can easily carry out the present invention by way of the following examples. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. In the drawings, the length, thickness, etc. of each component are shown for explaining the present invention, and the present invention is not limited to the length, thickness, etc. described in the drawings.

In the present specification, when describing a numerical range, "X to Y" means X or more and Y or less (X≤ and ≤Y).

In the adhesive film formed of a composition including a binder resin, an epoxy resin, and a filler, the inventor of the present invention necessarily includes the resin described in detail below as the binder resin. Through this, the present invention can ensure the minimum melt viscosity and ion migration described in detail below.

The temperature at which the adhesive film has a minimum melt viscosity after curing is 120° C. to 150° C., for example, 125° C. to 135° C., and the melt viscosity (minimum melt viscosity) at this time is 30,000 Pa.s to 60,000 Pa.s, for example. For example, it may be 35,000 Pa.s to 60,000 Pa.s. In the above range, there may be an effect of improving the filling and adhesion.

^{After curing, the adhesive film may have an ion movement of 1 x 10 12} Ω or more, for example, 1 x 10 ¹² Ω to 10 x 10 ¹³ Ω when a voltage of 50 V is applied under 85° C., 85% relative humidity, and 500 hours. In the above range, there may be an ionic insulation effect.

After curing, the adhesive film of the present invention had a low rate of change of a dielectric constant (Dk) and a dielectric loss (Df) according to a change in frequency.

As used herein, "dielectric constant" and "dielectric loss" refer to the dielectric constant and/or dielectric loss of the adhesive film after curing.

In the present specification, "dielectric constant" and "dielectric loss" mean values measured at 1 GHz to 10 GHz and 20° C. to 80° C. Preferably, the dielectric constant and the dielectric loss are values measured at 10 GHz and 25°C.

As will be described in detail below, the adhesive film of the present invention is in a semi-cured state (B stage).

Unless otherwise specified herein, "after curing" means curing the adhesive film at 150° C. to 200° C. for 45 minutes to 90 minutes. That is, for example, "dielectric constant after curing" means a dielectric constant measured after curing the adhesive film under the above-described conditions.

In the adhesive film of the present invention, the rate of change of the dielectric constant according to the frequency change of Equation 1 may be 0.6% or less, for example, 0% to 0.6%, and the rate of change of the dielectric loss according to the frequency change of Equation 2 is 0.01 % or less, for example 0% to 0.01%. Within the above range, the above-mentioned practicality and reliability can be ensured:

[Equation 1]

Rate of change of dielectric constant = │Dk(@10GHz) - Dk(@1GHz)│/│10-1│ x 100

(In Equation 1 above,

Dk (@10GHz) is the dielectric constant of the adhesive film at a frequency of 10GHz after curing,

Dk (@1GHz) is the dielectric constant of the adhesive film at a frequency of 1GHz after curing)

[Equation 2]

Rate of change of dielectric loss = │Df(@10GHz) - Df(@1GHz)│/│10-1│ x 100

(In Equation 2 above,

Df (@10 GHz) is the dielectric loss at a frequency of 10 GHz of the adhesive film after curing,

Df (@1GHz) is the dielectric loss at the frequency of 1GHz of the adhesive film after curing),

In general, the dielectric constant of the adhesive film decreases as the measurement frequency increases, and the dielectric loss of the adhesive film generally increases as the measurement frequency increases. The adhesive film of the present invention was able to increase the practicality and reliability of the laminate to be described in detail below by lowering the rate of change of the dielectric constant and the rate of change of the dielectric loss in the frequency change while ensuring the low dielectric constant and dielectric loss described below.

The adhesive film of the present invention has a low dielectric constant and a low dielectric loss after curing even in a wide frequency range and a wide temperature range, so that reliability during lamination of the metal foil described in detail below can be improved.

In one embodiment, the adhesive film may have a dielectric constant of 2.5 or less after curing, for example, 0 to 2.5 or less, 0.1 to 2.5, 2.0 to 2.45. In the above range, it is possible to minimize the electrical influence on the adhesive film by minimizing the movement of static electricity or electricity to the device to which the adhesive film is attached.

In one embodiment, the adhesive film may have a dielectric loss of 0.004 or less after curing, for example, 0 to 0.004, 0.0001 to 0.0035. In the above range, it is possible to minimize the electrical influence on the adhesive film by minimizing the movement of static electricity or electricity to the device to which the adhesive film is attached.

The adhesive film of the present invention is characterized in that the rate of change of the dielectric constant and the rate of change of the dielectric loss according to the frequency change while securing the above-described dielectric constant and dielectric loss are low. As a result, it is possible to increase the practicability by ensuring a uniform dielectric constant and dielectric loss even within a wide frequency range. In addition, the adhesive film of the present invention can secure practical feasibility by ensuring a uniform dielectric constant and dielectric loss even in a wide temperature change.

In one embodiment, in the adhesive film, the rate of change of the dielectric constant according to the temperature change of Equation 3 may be 0.3% or less, for example, 0% to 0.3%, and the rate of change of the dielectric loss according to the temperature change of Equation 4 It may be 0.001% or less, for example 0% to 0.001%. Within the above range, the above-mentioned practicality and reliability can be ensured:

[Equation 3]

Rate of change of dielectric constant = │Dk(@80℃) - Dk(@20℃)│/│80-20│ x 100

(In Equation 3 above,

Dk (@80℃) is the dielectric constant at 80℃ of the adhesive film after curing,

Dk (@20℃) is the dielectric constant of the adhesive film at 20℃ after curing)

[Equation 4]

Rate of change of dielectric loss = │Df(@80℃) - Df(@20℃)│/│80-20│ x 100

(In Equation 4 above,

Df (@80℃) is the dielectric loss at 80℃ of the adhesive film after curing,

Df (@20℃) is the dielectric loss at 20℃ of the adhesive film after curing)

In general, the dielectric constant and dielectric loss of the adhesive film are generally higher as the measurement temperature increases. The adhesive film of the present invention was able to increase the practicality and reliability of the laminate to be described in detail below by lowering the rate of change of the dielectric constant and the rate of change of the dielectric loss in a temperature change while ensuring the above-described dielectric constant and dielectric loss.

In one embodiment, the adhesive film may have a ratio of dielectric constant after curing to dielectric loss after curing (dielectric constant after curing/dielectric loss after curing) of 700 or more, for example, 900 to 2000, at the same frequency. . In the above range, when the adhesive film is applied to a laminate to be described in detail below, it is possible to increase adhesion reliability and improve adhesion and electrical properties between adherends.

In this specification, "moisture absorption rate" means a value measured by IPC-TM 650 2.6.2.1A for an adhesive film after curing. In one embodiment, the adhesive film may have a moisture absorption rate of 0.1% or less after curing, for example, 0% to 0.1%, 0.01% to 0.05%. Within the above range, it is possible to reduce the adverse effects caused by moisture introduced into the material from the air during component mounting, thereby preventing problems in adhesion or electrical properties between the respective materials.

The adhesive film may simultaneously satisfy the dielectric constant, dielectric loss and moisture absorption within the above-described ranges. Therefore, when the adhesive film is applied to the metal foil laminate to be described in detail below, it is possible to increase adhesion reliability and improve adhesion and electrical properties between adherends. For example, the adhesive film may be used for bonding a base film and a metal foil, such as a metal foil laminate. This is detailed below.

The adhesive film of the present invention is used for bonding the base film and the metal plate in the laminate to be described in detail below by securing flexibility in addition to the above-described electrical properties and barrier properties, and in particular, it can be made easy to manufacture a flexible printed circuit board.

In one embodiment, since the adhesive film has a low elastic modulus even after curing, flexibility may be secured and rigidity may be satisfied. In particular, since the adhesive film of the present invention has a lower ratio of elastic modulus between room temperature and high temperature compared to the conventional adhesive film, reliability can be secured in terms of flexibility between room temperature and high temperature.

In one embodiment, the adhesive film may have an elastic modulus at 25° C. after curing: an elastic modulus at 160° C. after curing = 100:1 to 1200:1, specifically 100:1 to 1100:1. In the above range, the elastic modulus between room temperature and high temperature is uniform, so that reliability in terms of flexibility can be secured.

In one embodiment, the adhesive film may have an elastic modulus of 0.1 GPa to 2 GPa, for example 0.1 GPa to 1.5 GPa at 25° C. after curing. In the above range, the flexibility of the adhesive film and the laminate having the same can be ensured due to the low elastic modulus at room temperature.

The adhesive film may have an elastic modulus of 0.1 MPa to 3.0 MPa at 130° C. or 160° C. after curing, for example, 1.0 MPa to 3.0 MPa. In the above range, it is possible to secure the flexibility of the adhesive film and the laminate having the same because the elastic modulus is low at high temperature. As such, since the adhesive film of the present invention has high flexibility at both room temperature and high temperature, it can increase the possibility of use when applied to a laminate to be described in detail below.

The adhesive film of the present invention has excellent peel strength with respect to a base film, for example, a polyimide film, and a metal foil, for example, a copper foil as much as it is applied to a metal foil laminate to be described in detail below, so that it can be excellent in adhesive reliability.

In one embodiment, the adhesive film may have a peel strength of 1Kgf/cm or more after curing measured for a laminate in which a polyimide film, an adhesive film, and a polyimide film are sequentially stacked. In the above range, it is possible to increase the adhesion reliability when the adhesive film is applied to the laminate to be described in detail below. For example, the peel strength may be 1Kgf/cm to 3Kgf/cm.

In another embodiment, the adhesive film may have a peel strength of 1Kgf/cm or more after curing, measured for a laminate in which a polyimide film, an adhesive film, and a metal foil are sequentially laminated after curing. In the above range, it is possible to increase the adhesion reliability when the adhesive film is applied to the laminate to be described in detail below. For example, the peel strength may be 1Kgf/cm to 3Kgf/cm. In this specification, "peel strength" means a value measured according to IPC-TM 650 2.4.8C standard.

The adhesive film may have a glass transition temperature of 60°C to 80°C after curing, for example, 60°C to 70°C. In the above range, there may be an excellent heat resistance effect.

After curing, the adhesive film may have a temperature at which a mass loss ratio of 5% according to Equation 5 occurs at 300°C to 500°C, for example, 350°C to 450°C. In the above range, the adhesive film is excellent in heat resistance and can be used in a laminate to be described in detail below.

[Equation 5]

Mass loss ratio = │ After curing, the mass of the adhesive film after warming - the initial mass of the adhesive film after curing │/ The initial mass of the adhesive film after curing x 100

The temperature at which the mass loss ratio of 5% occurs may be measured by thermogravimetric analysis (TGA). Specifically, with respect to the initial mass of 10 mg of the adhesive film, starting at an initial temperature of 25° C., it can be measured by heating at a rate of 10° C./min.

The adhesive film has a surface resistivity after curing of 1 x 10 ⁹ to 10 x 10 ¹⁰ MΩ, for example 1 x 10 ⁹ to It can be 1 x 10 ^{10 MΩ.} The adhesive film may have a volume resistivity after curing of 1 x 10 ⁹ to 10 x 10 ¹⁰ MΩ.cm, for example, 1 x 10 ⁹ to 1 x 10 ¹⁰ MΩ.cm. In the above range, there may be an insulating effect. In this specification, the surface resistance and the volume resistance may be measured by IPC TM-650 2.5.17, respectively.

The adhesive film may have a thickness of 10 μm to 200 μm, for example, 20 μm to 100 μm. Within the above range, it can be used in the laminate to be detailed below.

The adhesive film has a solder resistance of 288° C. or higher in the polyimide film/adhesive film/polyimide film after curing, and a solder resistance of 280° C. or higher in the polyimide film/adhesive film/metal foil after curing. can be In the above range, there may be an excellent heat resistance effect. Solder resistance may be measured by, but not limited to, IPC TM-650 2.4.13F.

The adhesive film of the present invention may be embodied by the composition detailed below. Hereinafter, the composition of the present invention will be described.

The composition includes a binder resin, an epoxy resin, and a filler, and the binder resin includes a carboxylic acid-modified olefin-based resin and a polyphenylene ether-based resin. The above composition must include a carboxylic acid-modified olefin-based resin and a polyphenylene ether resin as the olefin-based resin. If any one of the carboxylic acid-modified olefin-based resin and the polyphenylene ether-based resin is absent, or any one of them is substituted with a resin other than the resin described in detail below, the effects of the present invention cannot be properly implemented.

In one embodiment, the binder resin may be made of only two kinds of resins, a carboxylic acid-modified olefin-based resin and a polyphenylene ether-based resin.

In another embodiment, the binder resin may be made of only three types of resins (carboxylic acid-modified styrene-based elastomer, carboxylic acid-modified olefin-based resin and polyphenylene ether-based resin) further including a carboxylic acid-modified styrene-based elastomer.

The carboxylic acid-modified olefin-based resin may provide adhesiveness, flexibility, and electrical properties of the adhesive film as one component of the composition.

The carboxylic acid-modified olefin-based resin may include a linear polyolefin-based resin. In this case, the linear may include a linear or branched polyolefin-based resin, and preferably may include a linear polyolefin-based resin. In one embodiment, the olefin-based resin may include one or more of a polyethylene-based resin, a polypropylene-based resin, and a polybutylene-based resin. Preferably, the olefin-based resin may include a polypropylene-based resin, which may facilitate implementation of the effects of the present invention when included together with the above-described polyphenylene ether-based resin.

The carboxylic acid-modified olefin-based resin may include a polyolefin-based resin modified with a predetermined modified material, for example, an unsaturated carboxylic acid or an anhydride thereof. The unsaturated carboxylic acid or anhydride thereof may include, for example, at least one of acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric anhydride. Preferably, the modified material may be maleic anhydride.

The carboxylic acid-modified olefin-based resin may have an acid value of 0.5 to 1.5 mgCH ₃ ONa/g, for example, 0.51 to 1.5 mgCH ₃ ONa/g. Within the above range, good adhesion and heat resistance can be realized. The "acid value" may be measured by the ASTM D 1613 method.

The carboxylic acid-modified olefin-based resin may have a glass transition temperature of 5°C to 100°C, for example, 10°C to 50°C. Within the above range, there may be a heat-resistant effect.

The carboxylic acid-modified olefin-based resin may be included in an amount of 50 to 95 parts by weight out of 100 parts by weight of the total binder resin. In the above range, the dielectric constant and moisture absorption rate of the present invention can be reached, and there can be a good adhesion effect. Specifically, the carboxylic acid-modified olefin-based resin may be included in an amount of 50 to 85 parts by weight out of 100 parts by weight of the total binder resin.

The polyphenylene ether-based resin provides adhesiveness, flexibility, and electrical properties of the adhesive film as one component of the composition.

The polyphenylene ether-based resin may include at least one of unmodified polyphenylene ether and modified polyphenylene ether. Preferably, the polyphenylene ether-based resin may include unmodified polyphenylene ether.

As the polyphenylene ether-based resin, a type having a higher glass transition temperature than the carboxylic acid-modified olefin-based resin may be used. Through this, the effect of the present invention can be easily realized. The glass transition temperature difference between the polyphenylene ether-based resin and the carboxylic acid-modified olefin-based resin may be 100°C to 250°C, for example, 100°C to 150°C. The polyphenylene ether-based resin may have a glass transition temperature of greater than 100°C and less than or equal to 300°C, for example, 110°C to 200°C. Within the above range, there may be a heat-resistant effect.

The polyphenylene ether-based resin may be included in an amount of 5 to 50 parts by weight out of 100 parts by weight of the total binder resin. In the above range, the dielectric constant and moisture absorption of the present invention can be reached, and there can be a heat resistance effect. Specifically, the polyphenylene ether-based resin may be included in an amount of 5 parts by weight to 30 parts by weight, and 15 parts by weight to 50 parts by weight.

The carboxylic acid-modified styrene-based elastomer provides adhesiveness, flexibility, and electrical properties of the adhesive film as one component of the above-described composition. Carboxylic acid-modified styrene-based elastomers are obtained by modifying a random, block or alternating copolymer of a conjugated diene compound and an aromatic vinyl compound with an unsaturated carboxylic acid.

Examples of the conjugated diene compound include a conjugated diene compound having 4 to 10 carbon atoms. Examples of the conjugated diene compound include butadiene, isoprene, 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene. Preferably, the conjugated diene compound includes butadiene. Examples of the aromatic vinyl compound include styrene, methylstyrene, divinylbenzene, diphenylstyrene, and vinyltoluene. Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric acid anhydride.

In one embodiment, the carboxylic acid-modified styrene-based elastomer may include at least one of a styrene-ethylene-butylene-styrene copolymer, a styrene-butadiene-styrene copolymer, and a styrene-ethylene-propylene copolymer. Preferably, the carboxylic acid-modified styrene-based elastomer may be a styrene-ethylene-butylene-styrene copolymer, and the effect of the present invention may be well realized when included together with the olefin-based resin and polyphenylene ether-based resin described in detail below. have.

The carboxylic acid-modified styrene-based elastomer may have an acid value of 5 to 13 mgCH ₃ ONa/g, for example, 5.1 to 13.0 mgCH ₃ ONa/g. Within the above range, good adhesion and heat resistance can be realized. The "acid value" may be measured by the ASTM D 1613 method.

The carboxylic acid-modified styrene-based elastomer may have a lower glass transition temperature than the carboxylic acid-modified olefin-based resin and the polyphenylene ether-based resin. Through this, it is possible to reach the glass transition temperature of the adhesive film of the present invention described above. In one embodiment, the glass transition temperature difference between the carboxylic acid-modified olefin-based resin and the carboxylic acid-modified styrene-based elastomer may be 50°C to 120°C, for example, 50°C to 100°C. The glass transition temperature difference between the polyphenylene ether-based resin and the carboxylic acid-modified styrene-based elastomer may be 150°C to 300°C, for example, 150°C to 250°C.

The carboxylic acid-modified styrene-based elastomer may have a glass transition temperature of -80°C to -50°C, for example, -70°C to -50°C. In the above range, there may be an excellent flexibility effect.

The carboxylic acid-modified styrene-based elastomer may be included in an amount of 0 parts by weight to 20 parts by weight, specifically, 1 part by weight to 20 parts by weight of the total 100 parts by weight of the binder resin. In the above range, the dielectric constant and moisture absorption rate of the present invention can be reached, and there can be a bending resistance effect.

The epoxy resin may react with the carboxylic acid group of the above-described binder resin, particularly, the carboxylic acid-modified olefin-based resin to increase adhesion and heat resistance.

The epoxy resin may be included in an amount of 3 to 18 parts by weight based on 100 parts by weight of the total binder resin. In the above range, the dielectric constant and moisture absorption rate of the present invention can be reached, and there can be a good adhesion effect.

The epoxy resin may include a conventional epoxy resin known to those skilled in the art having two or more epoxy groups. For example, the epoxy resin is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bisphenol AD type epoxy resin, a rubber modified epoxy resin, a fatty acid modified epoxy resin, a urethane modified epoxy resin, a low chlorine type epoxy resin , silane-modified epoxy resin, dicyclopentadiene type epoxy resin, polyfunctional novolac type epoxy resin, glycidyl ether type epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, etc. may include, but are not limited to. Preferably, the epoxy resin may comprise a cresol novolac epoxy resin.

On the other hand, the above composition does not include a curing agent. The adhesive film of the present invention does not require an additional curing agent because the adhesive film is prepared only by the reaction of the epoxy group of the epoxy resin and the carboxylic acid among the olefin resins described above.

To this end, the ratio of the total number of moles of carboxylic acid groups in the binder resin to the total number of moles of epoxy groups in the epoxy resin may be 1 or more, for example, 1-2. In the above range, it is possible to implement the adhesive film of the present invention without a curing agent.

The filler may include at least one of an inorganic filler and an organic filler. Preferably, the filler may be a mixture of an inorganic filler and an organic filler. Through this, when combined with the above-described olefin resin and epoxy resin, the moisture absorption and dielectric constant of the present invention can be easily reached.

The inorganic filler may include at least one of a metal, a non-metal, a metal oxide, and a non-metal oxide. For example, the inorganic filler may include at least one of silica, titania, alumina, zinc oxide, copper, and silver. Preferably, the inorganic filler may include silica, for example, inorganic nano-silica. The inorganic filler may have an average particle diameter (D50) of 10 nm to 1000 nm, preferably 10 nm to 500 nm. In the above range, there may be an excellent volume expansion rate effect.

The organic filler may include a fluororesin filler. The fluororesin filler is, for example, a polytetrafluoroethylene filler, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer filler, a tetrafluoroethylene-hexafluoropropylene copolymer filler, and a tetrafluoroethylene-ethylene copolymer. It may include one or more of a coalescing filler and a polychlorotrifluoroethylene filler. Preferably the organic filler may comprise a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer filler. The organic filler may have an average particle diameter of 1 μm to 100 μm, preferably 5 μm to 50 μm. In the above range, there may be a stable shrinkage effect.

The inorganic filler and the organic filler may be included in a specific content ratio in the adhesive composition of the present invention. For example, based on 100 parts by weight of the inorganic filler, the organic filler may be included in an amount of 100 parts by weight to 800 parts by weight, for example, 100 parts by weight to 600 parts by weight. In the above range, there may be an optimal shrinkage change rate effect.

The filler may be included in an amount of 1 to 50 parts by weight, for example, 1 to 30 parts by weight, based on 100 parts by weight of the total binder resin. In the above range, the dielectric constant may be lowered.

The above-described composition may further include at least one of a plasticizer, a leveling agent, an additive such as a UV absorber, a flame retardant, and a thickener, if necessary, but is not limited thereto.

The above-described composition may improve the applicability of the adhesive film by further including a solvent. The solvent may include at least one of dimethylformamide, methylethylketone, and dimethylacetamide, but is not limited thereto.

The adhesive film may be prepared in a semi-cured state by applying the above-described composition to a base film or a release film to a predetermined thickness, drying and heat treatment. For example, the adhesive film may be prepared in a semi-cured state by heat treatment at 50° C. to 170° C. for 1 minute to 60 minutes.

Hereinafter, a laminate with an adhesive film according to an embodiment of the present invention will be described.

The laminate with an adhesive film of the present invention includes a base film and an adhesive film provided on at least one surface of the base film, and the adhesive film includes the adhesive film of the present invention. The laminate with an adhesive film of the present invention may include, but is not limited to, a coverlay film.

Referring to FIG. 1 , the adhesive film-attached laminate includes a base film 10 , a first adhesive film 20 provided on one surface of the base film 10 , and a second adhesive provided on the other surface of the base film 10 . The film 30 is provided, and at least one of the first adhesive film 20 and the second adhesive film 30 may include the adhesive film of the present invention.

The base film 10 includes a film formed of a polyimide resin. The polyimide resin is a resin that provides high heat resistance, and can make a laminate with an adhesive film suitable for use as a coverlay film. The thickness of the base film 10 may be 5 μm to 100 μm, preferably 5 μm to 50 μm. In the above range, it may be used as a base film of the coverlay film, and both ductility and rigidity may be implemented.

Each of the first adhesive film 20 and the second adhesive film 30 may be the adhesive film of the present invention described above, and only one of the first adhesive film 20 and the second adhesive film 30 is It can be an adhesive film. The first adhesive film 20 and the second adhesive film 30 may be adhesive films in a semi-cured state, that is, in a B-stage state.

The first adhesive film 20 and the second adhesive film 30 may have the same or different thicknesses, for example, the thickness range of the adhesive film of the present invention described above.

Hereinafter, a metal foil laminate of an embodiment of the present invention will be described.

The metal foil laminate of the present invention includes a base film, an adhesive film provided on at least one surface of the base film, and a metal foil provided on one surface of the adhesive film, wherein the adhesive film includes the adhesive film of the present invention. The metal foil laminate of the present invention may include a printed circuit board, for example, a flexible circuit board.

2, the metal foil laminate is a base film 10, a first adhesive film 20 provided on one surface of the base film 10, and a first metal foil provided on one surface of the first adhesive film 20 ( 40), a second adhesive film 30 provided on the other surface of the base film 10, and a second metal foil 50 provided on one surface of the second adhesive film 30 may be provided.

Descriptions of the base film 10 , the first adhesive film 20 , and the second adhesive film 30 are the same as those described with reference to FIG. 1 . The first metal foil 40 and the second metal foil 50 may include at least one of copper foil, silver foil, aluminum foil, and stainless foil, and preferably include copper foil. The first metal foil 40 and the second metal foil 50 may be the same copper foil, one of which may be a copper foil, and the other may be a metal foil other than the copper foil. The thickness of each of the first metal foil 40 and the second metal foil 50 may be the same or different, for example, 5 μm to 200 μm, for example, 10 μm to 150 μm.

Hereinafter, the present invention will be described in more detail through examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example 1

Carboxylic acid-modified polypropylene resin (SM040A, Toyobo, acid value: 1.0 mgCH ₃ ONa/g) 54 parts by weight, polyphenylene ether-based resin (PPO, Sabic, -OH value: 800 mgKOH/g) 16 parts by weight, cresolno 11 parts by weight of rock epoxy resin (YDCN1P, Kukdo Chemical, EEW: 20eq/g), 5 parts by weight of inorganic nano silica (R972, Evonik, average particle diameter (D50): 17 nm), fluororesin filler (PFA, AGC, average particle diameter) (D50): 10 µm) 14 parts by weight were mixed, and 150 parts by weight of a solvent methyl ethyl ketone was further added to prepare a composition.

The prepared composition was coated on a polyimide film to a predetermined thickness, dried and heat treated at 130° C. for 3 minutes to prepare an adhesive film (thickness: 25 μm) in a semi-cured state.

Example 2

Carboxylic acid-modified styrenic elastomer (SM300A, Toyobo, acid value: 10 mgCH ₃ ONa/g) 11 parts by weight, carboxylic acid-modified polypropylene resin (SM040A, acid value: 1.0 mgCH ₃ ONa/g, Toyobo) 62 parts by weight, poly 7 parts by weight of phenylene ether-based resin (PPO, -OH value: 800 mgKOH/g, SABIC), 6 parts by weight of cresol novolac epoxy resin (YDCN1P, EEW: 200 eq/g, Kukdo Chemical), inorganic nano silica (R972, average Particle size (D50): 17 nm, Evonik) 6 parts by weight, fluororesin filler (PFA, average particle diameter (D50): 10 μm, AGC) 8 parts by weight are mixed, and 150 parts by weight of solvent methyl ethyl ketone is further added to prepare the composition. prepared.

An adhesive film was prepared in the same manner as in Example 1 using the prepared composition.

Examples 3 and 4

In Example 1, an adhesive film in a semi-cured state was prepared in the same manner as in Example 1, except that the content of each component was changed as shown in Table 1 below. In Table 1, the unit is parts by weight, and "-" means that the corresponding component is not included.

Comparative Example 1

As a non-halogen epoxy resin, 100 parts by weight of p-Amino Phenol type (jER630, Mitsubishi Chemical, EEW: 100eq/g), 50 parts by weight of a biphenyl type epoxy resin (NC3000H, Nippon Chemicals, EEW: 290eq/g), containing a carboxylic acid group 50 parts by weight of acrylonitrile butadiene rubber (Nipol1072, Nippon Zeon, -COOH: 8% by weight), 4,4-diaminodiphenylsulfone (DDS, Sigma-Aldrich, EEW: 64eq/g) as a curing agent for epoxy resins, by 16 weight parts, 20 parts by weight of polyphenylene ether-based resin (PPO, Sabic, -OH value: 800 mgKOH/g), 0.5 parts by weight of undecylimidazole (C11Z, Shikoku Kasei) as a curing accelerator, and 150 parts by weight of solvent methyl ethyl ketone Further parts were added to prepare a composition.

An adhesive film was prepared in the same manner as in Example 1 using the prepared composition.

Comparative Example 2

60 parts by weight of non-halogen-modified polyimideamide-based resin (PIAD200, Arakawa), 25 parts by weight of non-halogen-modified polyimideamide-based resin (PIAD150L, Arakawa), non-halogenated epoxy resin p-Amino Phenol type (jER630, Mitsubishi Chemical, EEW) : 100 eq/g) 5 parts by weight, 10 parts by weight of an ester-modified curing agent (HPC-8150, DIC), and 0.05 parts by weight of 2-ethyl 4-methylimidazole (2E4MZ, Shikoku Kasei) as a curing accelerator were mixed, and the solvent was methyl ethyl ketone. An additional 150 parts by weight was added to prepare a composition.

An adhesive film was prepared in the same manner as in Example 1 using the prepared composition.

Comparative Example 3

Carboxylic acid-modified styrene-based elastomer (SM300A, Toyobo, acid value: 10 mgCH ₃ ONa/g) 9 parts by weight, polypropylene resin (JSS-395N, acid value: 0 mgCH ₃ ONa/g, Honam Petrochemical, carboxylic acid unmodified) ) 55 parts by weight, polyphenylene ether-based resin (PPO, -OH value: 800 mgKOH/g, Sabic) 12 parts by weight, cresol novolac epoxy resin (YDCN1P, EEW: 200 eq/g, Kukdo Chemical) 3 parts by weight, inorganic 5 parts by weight of nano silica (R972, average particle diameter (D50): 17 nm, Evonik), 16 parts by weight of a fluororesin filler (PFA, average particle diameter (D50): 10 μm, AGC), curing agent (4,4-DDS, Sigma) -Aldrich) 1.55 parts by weight was mixed, and 150 parts by weight of a solvent methyl ethyl ketone was further added to prepare a composition.

An adhesive film was prepared in the same manner as in Example 1 using the prepared composition.

The adhesive films of Examples and Comparative Examples were heat-treated at 120° C. for 60 minutes to prepare an adhesive film in a fully cured state. The following physical properties were evaluated for the adhesive film in a cured state, and the results are shown in Tables 2 and 3 and FIGS. 3 and 4 below.

(1) Peel strength (unit: Kgf/cm): Peel strength was evaluated according to IPC TM-650 2.4.8C. For polyimide (PI) film/adhesive film/polyimide film, polyimide film/adhesive film/copper foil (Cu), peel strength was evaluated by 25° C., peel angle 180°, and peel rate 50 mm/min.

(2) Solder resistance (unit: deg. C/sec): Measured by IPC TM-650 2.4.13F. Solder resistance was measured for polyimide (PI) film/adhesive film/polyimide (PI) film, polyimide (PI) film/adhesive film/copper foil (Cu).

(3) Dielectric constant (unit: none) and dielectric loss (unit: none): For the adhesive film, the dielectric constant (Dk) and the dielectric loss using a network analyzer (MS4642B 36585K, Anritsu Co.) at 25℃, frequency 10GHz (Df) was evaluated.

(4) Glass transition temperature (unit: ℃): For the adhesive film, using a dynamic mechanical analyzer (DMA), the temperature at which the tanδ modulus is maximized was called the glass transition temperature.

(5) Elastic modulus (unit: MPa): The elastic modulus (E") was confirmed by measuring from an initial temperature of 25°C to 200°C using a dynamic mechanical analyzer (DMA).

(6) The minimum melt viscosity and the temperature at which the minimum melt viscosity appears (unit: Pa.s, unit: °C): The minimum melt viscosity was evaluated by ARES according to temperature.

(7) Coefficient of thermal expansion (unit: ppm/°C): For the adhesive film, α1 and α2 were analyzed using a thermomechanical analyzer (TMA) according to IPC TM-650 2.4.41.3.

(8) 5% mass loss temperature (unit: ° C.): 5% mass loss for the adhesive film was analyzed by thermogravimetric analysis (TGA).

(9) Surface resistance and volume resistance (units are MΩ and MΩ.cm, respectively): The surface resistance and volume resistance of the adhesive film were evaluated according to IPC-TM-6500 2.5.17.

(10) Ion-migration (unit: Ω): For the adhesive film, ion migration was evaluated at 85° C., 85%, 500 hours, 50V, L/S=50 μm/50 μm.

(11) Moisture absorption rate (unit: %): For the adhesive film, the moisture absorption rate was measured according to IPC TM-650 2.6.2.1A.

(12) Dielectric constant and dielectric loss according to frequency change: Measure the dielectric constant and dielectric loss in the same way as (3), but measure the dielectric constant and dielectric loss while changing the frequency to 1GHz, 3GHz, 5GHz, and 10GHz at 25℃ did. The rate of change was calculated using Equation 1 and Equation 2 above.

(13) Dielectric constant and dielectric loss according to temperature change: Measure the dielectric constant and dielectric loss in the same way as in (3), but change the measured temperature at 10 GHz to 20℃, 40℃, 60℃, 80℃ Dielectric loss was measured. The rate of change was calculated using Equation 3 and Equation 4 above.

[Table 1]

[Table 2]

*Elastic modulus ratio: elastic modulus at 25℃ / elastic modulus at 160℃

[Table 3]

As shown in Tables 2, 3, 3, and 4, the adhesive film of the present invention had a low rate of change in dielectric constant and dielectric loss according to frequency change and temperature change, and had a minimum melt viscosity in a specific range and resistance was It was low and the ion movement was able to secure an appropriate range.

On the other hand, Comparative Example 1, which is a conventional acrylonitrile-butadiene-based adhesive film, Comparative Example 2, which is a polyimide-based adhesive film, and Comparative Example 3, which includes an unmodified olefin-based resin and a curing agent, could not obtain the effect of the present invention. .

Simple modifications or changes of the present invention can be easily carried out by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (18)

As an adhesive film formed of a composition comprising a binder resin, an epoxy resin and a filler,
The adhesive film has a minimum melt viscosity of 30,000 Pa.s to 60,000 Pa.s after curing,
^{After curing, the adhesive film has an ion movement of 1 x 10 12} Ω or more when a voltage of 50V is applied under 85° C., 85% relative humidity and 500 hours after curing.
According to claim 1, wherein the adhesive film has a dielectric constant of 2.5 or less and a dielectric loss (Df) of 0.004 or less measured at 1 GHz to 10 GHz and 20 ° C to 80 ° C after curing, and the adhesive film absorbs moisture after curing The rate is 0.1% or less, the adhesive film.
The adhesive film of claim 1 , wherein the composition does not include a curing agent.
According to claim 1, wherein the ratio of the total number of moles of carboxylic acid groups in the binder resin to the total number of moles of epoxy groups in the epoxy resin ([Total moles of carboxylic acid groups in the binder resin]/[Total moles of epoxy groups in the epoxy resin]) is 1 to 2, the adhesive film.
The adhesive film according to claim 1, wherein the binder resin includes a carboxylic acid-modified olefin-based resin and a polyphenylene ether-based resin.
The method of claim 5, wherein the carboxylic acid-modified olefin-based resin comprises an olefin-based resin modified with at least one of acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, maleic anhydride, itaconic anhydride, and fumaric anhydride. The thing to do is an adhesive film.
The adhesion of claim 5, wherein the carboxylic acid-modified olefin-based resin is included in an amount of 50 parts by weight to 95 parts by weight, and the polyphenylene ether-based resin is included in an amount of 5 parts by weight to 50 parts by weight among 100 parts by weight of the total binder resin. film.
The adhesive film according to claim 5, wherein the binder resin further comprises a carboxylic acid-modified styrene-based elastomer.
The method of claim 8, wherein the carboxylic acid-modified olefin-based resin is 50 parts by weight to 85 parts by weight of the total of 100 parts by weight of the binder resin, the polyphenylene ether-based resin is 5 to 30 parts by weight, the carboxylic acid-modified styrene-based resin The adhesive film which is included in 1 part by weight to 20 parts by weight of the elastomer.
The adhesive film according to claim 5, wherein the carboxylic acid-modified olefin-based resin comprises a carboxylic acid-modified linear polypropylene-based resin.
The adhesive film according to claim 1, wherein the filler comprises a mixture of inorganic nano silica and a fluororesin filler.
The adhesive film according to claim 11, wherein the fluororesin filler is included in an amount of 100 parts by weight to 800 parts by weight based on 100 parts by weight of the inorganic nano-silica.
According to claim 1, With respect to 100 parts by weight of the binder resin, 3 parts by weight to 18 parts by weight of the epoxy resin, and 1 part by weight to 50 parts by weight of the filler, the adhesive film.
A polyimide-based resin film, an adhesive film provided on at least one surface of the polyimide-based resin film, wherein the adhesive film comprises the adhesive film of any one of claims 1 to 13, with an adhesive film attached laminate.
The laminate with an adhesive film according to claim 14, wherein the laminate with an adhesive film comprises a coverlay film.
A polyimide-based resin film, an adhesive film provided on at least one surface of the polyimide-based resin film, and a metal foil provided on one surface of the adhesive film, wherein the adhesive film is disposed between the polyimide-based resin film and the metal foil. provided,
The adhesive film is a metal foil laminate comprising the adhesive film of any one of claims 1 to 13.
The metal foil laminate according to claim 16, wherein the metal foil comprises a copper foil.
The metal foil laminate according to claim 16, wherein the metal foil laminate comprises a flexible circuit board.

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