KR20090013921A - Polyimide film for electronic device component - Google Patents

Abstract

A polyimide film is provided to ensure high elastic modulus, low thermal expansion coefficient, low hygroscopic rate, low hygroscopic expansion coefficient and excellent alkali resistant and to show adhesive strength to metal and flextural endurance in application to electronics. A polyimide film comprises 30-100 mole % of 2,2'- bis(4-(3,4-dicarboxyphenoxy)phenyl)propane dianhydride and 3,3',4,4'-biphenyltetra carboxylic acid dianhydride as an aromatic acid di-anhydride component, based on the acid di-anhydride component; and 50-100 mole % of paraphenylene diamine as and aromatic diamine component based on the total diamine component.

Description

Polyimide film for electronic device parts {POLYIMIDE FILM FOR ELECTRONIC DEVICE COMPONENT}

The present invention relates to polyimide films useful for electronic component parts.

The polyimide film has excellent mechanical dimensional stability as well as heat resistance, chemical resistance, and electrical insulation, and in particular, in the field of electronic component parts such as semiconductor insulating tapes and flexible printed circuit boards using excellent heat and electrical insulation properties; FPCB), an insulating substrate for tape automated bonding (TAB), a chip on film (COF), and the like.

In recent years, with the rapid development of circuit manufacturing technology and component mounting technology, FPCB for COF is rapidly becoming fine pitch. In order to cope with the development of the fine pitch mounting technology of COF, the circuit of the FPCB should be able to be manufactured without a short circuit. For this purpose, not only the circuit manufacturing technology but also the dimensional stability of heating and tensile force of the polyimide film, which is an insulating material, are very important. . In general, the dimensional stability against heating is better at lower coefficient of thermal expansion (CTE), and the dimensional stability at tensile strength is better at higher elastic modulus. Conventionally, a technique for producing a film using a monomer having a high linearity and rigid structure such as pyromellitic dianhydride or paraphenylene diamine is known as a method for producing a film having a low coefficient of thermal expansion and a high modulus of elasticity. However, the above technique is made of only a rigid raw material, which can achieve extremely low coefficient of thermal expansion and high modulus of elasticity. However, due to the lack of flexibility of the film, it does not satisfy the flexibility required for flexible circuit boards. When only the monomer having a very high electron affinity such as water is used, there is a problem that the moisture absorption of the final polyimide film is increased.

In addition, unlike other polymer materials, polyimide has a rather high moisture absorption rate, and accordingly, there is an increasing demand for a film having a low moisture absorption rate and a low hygroscopic expansion coefficient according to the progress of the fine pitch of the circuit. If the moisture absorption rate or the moisture absorption expansion coefficient is large, a dimensional change may occur due to moisture absorption during the FPCB process, thereby causing a short circuit between circuits or a problem of changing a distance between patterns. In order to solve this problem, a process for producing a film using a monomer having a low moisture absorption, for example, a fluorine monomer such as 2,2-bis (3,4-anhydrodicarboxyphenyl) hexafluoropropane This is known. However, such a fluorine-based monomer is not only very expensive, but also has a low reactivity, making it difficult to manufacture a resin.

U.S. Patent No. 5,166,308 uses 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 4,4'-diaminodiphenylether and paraphenylene diamine. A four-component polyimide film is disclosed. According to the embodiment disclosed in the patent, the film thus prepared has a thermal expansion coefficient of 8.0 to 22.0 ppm / ° C, a hygroscopic expansion coefficient of 16.8 to 29.8 ppm /% RH, and 2.26% to 4 hours when left at 100% RH at room temperature. It has a moisture absorption rate of 2.84% and shows an improved thermal expansion coefficient, moisture absorption rate and moisture absorption expansion coefficient, etc., compared to the existing two-component or three-component film, but is insufficient for use in the micro pitch manufacturing process. In addition, the film thus prepared is faster than other films having an alkali etching rate as mentioned in the above patent, which means that the alkali resistance is not good. When the alkali resistance is insufficient in the COF manufacturing process, dimensional change occurs in the alkali etching process, so that it is difficult to maintain the interval of the fine pitch, and there is a problem that the adhesion between the film and the copper foil is lowered by the alkaline liquid.

In addition, if mechanical, thermal, and chemical dimensional stability are not sufficiently secured, and if a change in dimension occurs due to a factor, the change in the mounting position of the drive may increase as time passes by accumulating the dimension change in the IC drive's continuous mounting process. Finally, the production yield of COF and the like can be significantly reduced.

Therefore, there is an urgent need to develop a polyimide film that satisfies high modulus of elasticity, low coefficient of thermal expansion, low moisture absorption, and excellent alkali resistance at the same time as an electronic device material.

Accordingly, it is an object of the present invention to provide a polyimide film that satisfies the high modulus of elasticity, low thermal expansion coefficient, low moisture absorption rate, low moisture absorption coefficient and excellent alkali resistance required for electronic material such as FPCB, COF or TAB. .

In order to achieve the above object, the present invention provides a 2,2'-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride and 3,3 ', 4, 30 to 100 mol% of 4'-biphenyltetracarboxylic dianhydride in the total acid dianhydride component, and 50 to 100 mol% of paraphenylene diamine in the total diamine component as aromatic diamine component. It provides a polyimide film characterized by.

Hereinafter, the present invention will be described in more detail.

The polyimide film according to the present invention comprises 2,2'-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride as an acid dianhydride component of a polyamic acid resin used as a precursor. And 3 ', 4,4'-biphenyltetracarboxylic dianhydride, which contains paraphenylene diamine as an essential component as a diamine component.

In the present invention, 2,2'-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride (BPADA) and 3,3 which are essentially used as the acid dianhydride component of the polyamic acid resin. The molar ratio of ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) ranges from 6:94 to 80:20 and the content of BPADA and BPDA in the total acid dianhydride component is from 30 to 100 mol%.

When the BPADA is less than 6 mol% compared to the BPDA, the adhesion between the polyimide film and the copper foil is decreased, particularly in the flexible copper clad laminate (FCCL) which undergoes the sputtering and plating process, and thus the final decrease in adhesion. Flexural resistance of the circuit may also be lowered. In addition, in the present invention, since a large amount of paraphenylene diamine having a rigid structure is used as the diamine component, when the BPADA is less than 6 mol% compared to the BPDA, the final film becomes excessively rigid and has a level of flex resistance that is suitable for FPCB use. Difficult to secure On the other hand, when the BPADA exceeds 80 mol% compared to the BPDA, the glass transition temperature of the final film is too low to ensure satisfactory dimensional stability in the mounting process, it may be difficult to control the bubble generation in the film manufacturing process. In addition, even when a film having a good appearance is produced, the coefficient of thermal expansion increases, causing a problem of severe curl in the FPCB manufacturing process and the mounting process.

On the other hand, when the content of BPADA and BPDA in the total acid dianhydride component is less than 30 mol%, the moisture absorption rate and the moisture absorption expansion coefficient of the final polyimide film may increase, and alkali resistance may be poor. In particular, when the molar ratio of BPDA and BPADA and the content of BPDA and BPADA relative to the total acid dianhydride do not satisfy the above range, the alkali resistance of the final film becomes very poor.

In addition, in the present invention, as the acid dianhydride component used for preparing the copolymerized polyamic acid, other aromatic acid dianhydrides, aliphatic acid dianhydrides and alicyclic acid dianhydrides may be further used together with BPADA and BPDA. It is preferable to use aromatic acid dianhydride from the viewpoint of preventing heat resistance fall. Examples of aromatic acid dianhydrides include pyromellitic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,4,3 ', 4'-benzophenone tetracarboxylic dianhydride, 3,4,3', 4'- Diphenylsulfone tetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,4,5, 8-naphthalene tetracarboxylic dianhydride, 3,4,9,10-perylene tetracarboxylic dianhydride, and derivatives thereof. Either one can be selected or a combination of two or more can be used with BPADA and BPDA.

In addition, the copolymerized polyamic acid used for producing the polyimide film of the present invention can use paraphenylene diamine (PPD) as a diamine component in a range of 50 to 100 mol% with respect to all diamine components. When the content of PPD is less than 50 mol%, there is a problem in that the coefficient of thermal expansion of the polyimide film is increased and the tensile modulus is lowered.

In the present invention, in the production of the polyamic acid resin, as the diamine component, aliphatic diamine, alicyclic diamine or other aromatic diamine can be used in an amount of 50 mol% or less together with the PPD. It is preferable to use an aromatic diamine in order to prevent the fall of the heat resistance and elastic modulus of a film, For example, 4,4'- diamino diphenyl propane, 4,4'- diamino diphenyl methane, benzidine, 4, 4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-bis (4-aminophenoxy) diphenyl sulfone, 4, 4'-bis (3-aminophenoxy) diphenyl sulfone, 3,6-chioxanthenediamine-10,10-dioxide, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide , 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,5-diamino naphthalene, 2,6-diaminonaphthalene, 4,4'-bis (4-amino Phenoxy) biphenyl, 2,2'-bis (4- (4-aminophenoxy) phenyl) propane, 4,4'-diaminodiphenyl diethyl silane, 4,4'-diaminodiphenyl silane, 4,4'-diaminodiphenyl ethyl foam Spin oxide, metaphenylenediamine, orthophenylenediamine, 1,3-bis (4-aminophenoxy) benzene, and derivatives thereof, and the like, and one or a combination of two or more thereof may be used. .

The copolymerized polyamic acid solution, which is a precursor of the polyimide of the present invention, can be prepared using known methods, for example, by the following methods:

(1) Aromatic tetracarboxylic dianhydride and an excessively molar amount of aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having an acid anhydride group at the end thereof, and then, in the previous step, aromatic tetracarboxylic dianhydride and aromatic dia. A method of polymerizing while adding an aromatic diamine compound such that the min compound is substantially equimolar;

(2) The aromatic tetracarboxylic dianhydride and the excess molar amount of the aromatic diamine compound are reacted in an organic polar solvent to obtain a prepolymer having an amino group at the end thereof, and then the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are A method of polymerizing while adding aromatic tetracarboxylic dianhydride so as to be substantially equimolar;

(3) a method in which the aromatic diamine is dissolved in an organic polar solvent and reacted with substantially equimolar aromatic tetracarboxylic dianhydride to polymerize;

(4) a method in which the aromatic tetracarboxylic dianhydride is dissolved and / or dispersed in an organic polar solvent and then polymerized while adding an aromatic diamine compound to be substantially equimolar; or

(5) A method in which a mixture of substantially equimolar aromatic tetracarboxylic dianhydride and an aromatic diamine compound is reacted in an organic polar solvent to polymerize.

Solvents usable in the process for synthesizing polyamic acid include, as polar aprotic solvents, N, N-dimethylformamide, N-methyl-2-pyrrolidone and N, N-dimethylacetamide. One of them may be selected, or two or more may be used in combination.

Subsequently, the polyamic acid solution prepared as described above is imidated by conventional thermal or chemical curing to be converted into polyimide. The thermal curing method is a method in which the imidization reaction proceeds only by heating without using a dehydrating agent or an imidization catalyst, and the chemical curing method is a dehydrating agent represented by an acid anhydride, such as acetic anhydride, in an organic solvent solution of polyamic acid, and iso It is the method of making it react by adding the imidation catalyst represented by tertiary amines, such as quinoline, (beta)-picoline, or pyridine.

The manufacturing process of the polyimide film according to the present invention using the polyamic acid solution prepared as described above is not particularly limited, and may be performed by, for example, the following method.

First, the dehydrating agent and the imidization catalyst are mixed in a polyamic acid solution at low temperature, and then the mixture is applied or cast on a support such as a support plate, a rotating drum or a steel belt, and then 50 to 200 ° C., preferably on a support. Is partially cured and dried by heating to a temperature in the range of 70 ° C. to 150 ° C. to activate the dehydrating agent and catalyst, thereby obtaining a gel film which is a self-supporting film.

Then, the end of the obtained polyamic acid gel film is fixed on a support and then heated, whereupon it is heated for 3 to 30 minutes at a temperature of 200 to 600 ° C. in order to completely imidize the remaining amic acid, followed by dehydration ring drying. . In this case, when the heating temperature is higher than the above range or the heating time is long, deterioration of the film occurs, which is not preferable. On the contrary, when the heating temperature is lower than the above range or the heating time is shortened, imidization is not sufficiently performed. The film is fragile.

The polyimide film prepared as above has an average thickness in the range of 7 to 125 μm.

The polyimide film according to the present invention has a tensile modulus of 4.5 to 9.0 GPa and a thermal expansion coefficient of 10 to 25 ppm / ° C measured in a temperature range of 50 to 200 ° C. In addition, when left at 99% RH for 24 hours at room temperature, the moisture absorption rate is 2.0% or less, preferably 1.5% or less, and the moisture absorption expansion coefficient is 20 ppm /% RH or less at a temperature of 23 ° C. and 20% RH at 80% RH. Preferably it is 18 ppm /% RH or less, and an alkali reduction rate is 5 weight% or less, Preferably it is 4 weight% or less when it is treated for 4 hours with 5 weight% NaOH aqueous solution at 55 degreeC.

When the tensile modulus of elasticity is less than 4.5 GPa, the resistance to external force of the film is small, so that the dimensional change easily occurs even at a small external force. On the other hand, if it exceeds 9.0 GPa, the resistance to external force increases, but the stiffness of the film increases, and the flexibility of the FCCL manufactured from this film may be poor. On the other hand, when the coefficient of thermal expansion is less than 10ppm / ℃ or more than 25ppm / ℃, the thermal expansion coefficient deviation with the copper foil becomes large, there is a problem that the curl (curl) is generated by heat in the FCCL manufacturing process, circuit manufacturing process or drive mounting process, When repeated heating and cooling are repeated, fatigue breakage is likely to occur due to variations in the coefficient of thermal expansion, which causes problems in circuit reliability. In addition, when the moisture absorption rate when left at 99% RH for 24 hours at room temperature exceeds 2.0%, there is a problem that the moisture absorption expansion coefficient of the film increases, and in the case of the two-layer FCCL manufactured by the sputtering and plating process, the vacuum reaching time during sputtering This becomes long and sputtering uniformity may worsen. In addition, when the moisture absorption rate is high, the adhesion is severely degraded under severe conditions such as, for example, the Pressure Cooker Test (PCT).

If the hygroscopic expansion coefficient exceeds 20ppm /% RH, the difference in the dimensions according to the humidity environment in the FCCL manufacturing process and the humidity environment during use of the finished FCCL may increase, resulting in curling, the rate of change of the film and the copper foil. The gap between circuits may change or short circuit or disconnection may occur due to the difference in the rate of dimensional change.

In addition, the polyimide film of the present invention has a resistance to 5% by weight of NaOH aqueous solution at 55 ° C. when the alkali reduction ratio is measured after 4 hours of immersion. If the alkali reduction rate exceeds 5% by weight, the alkali resistance is poor, resulting in dimensional change caused by alkaline liquid during circuit fabrication, which causes a defect in the drive IC mounting process, and also causes a problem that the adhesion between the film and the copper layer is degraded. Can be.

The polyimide film of the present invention that satisfies the above properties is used in electronic materials such as flexible circuit boards according to a conventional method to impart excellent metal adhesion, flex resistance, dimensional change rate after etching, and curl. can do. For example, the polyimide film of the present invention has a metal adhesive force of 0.62 kN / m or more, preferably 0.68 kN / m or more, based on the room temperature peel strength when used in the manufacture of a two-layer flexible copper foil laminate (FCCL), and a pressure cooker test (PCT). The peel strength is 0.45 kN / m or more, preferably 0.50 kN / m or more. In addition, the flex resistance is 130 times or more, preferably 150 times or more, and the dimensional change rate after etching is -0.05% to + 0.05%, and curls can be imparted to excellent physical properties of 2 mm or less.

The polyimide film according to the present invention satisfies high elastic modulus, low thermal expansion coefficient, low moisture absorption coefficient, low moisture absorption expansion coefficient and excellent alkali resistance at the same time, and has excellent metal adhesion strength, bending resistance, dimensional change rate and curl after etching. Therefore, it can be usefully used in the field of electronic components.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1

635.21 g of dimethylacetamide (DMAc) was added to the reactor, and the reaction temperature was set to 40 ° C. Here, 17.39 g of p-phenylene diamine (PPD) (60 mol% of the total diamine component) and 21.40 g of 4,4'-diaminodiphenyl ether (DPE) (40 mol% of the total diamine component) It was added and stirred until complete dissolution. After dissolution was complete, 63.21 g of 3,3 ', 3,4'-biphenyltetracarboxylic dianhydride (BPDA) (80 mol% of the total acid dianhydride component) and 2,2'-bis (4- (3, 28.11 g of 4-dicarboxyphenoxy) phenyl) propane dianhydride (BPADA) (20 mol% of the total acid dianhydride component) was gradually added to adjust the acid dianhydride and diamine to equimolar, followed by stirring for 1 hour. A solution of polyamic acid in DMAc was obtained.

The polyamic acid solution obtained above was mixed with 5 molar equivalents of acetic anhydride (AA) (based on 1 molar equivalent of polyamic acid) and 1 molar equivalent of isoquinoline (IQ) (based on 1 molar equivalent of polyamic acid), and then the mixed liquid Was applied on a glass plate with a uniform thickness, dried at 110 ° C. for 10 minutes, and then peeled to prepare a gel film. Then, the gel film was pinned to the support frame, and then heated at 250 ° C. for 5 minutes and at 450 ° C. for 5 minutes to dehydrate and ring-dry to obtain a polyimide film having a thickness of 38 μm.

Example 2

Example 1 except that 635.39 g of DMAc, 33.70 g of PPD (100 mol%) as the diamine component and 54.98 g (60 mol%) of BPDA and 24.46 g (40 mol%) of BPADA as the acid dianhydride component were used. A polyimide film having a thickness of 38 μm was prepared in the same manner.

Example 3

634.89 g of DMAc, 19.33 g (60 mol%) of PPD as a diamine component, 23.80 g (40 mol%) of DPE, 67.33 g (77 mol%) of BPDA as an acid dianhydride component, 7.81 g (5 mol%) of BPADA and fatigue A polyimide film having a thickness of 38 μm was prepared in the same manner as in Example 1, except that 11.77 g (18 mol%) of melic acid dianhydride (PMDA) was used.

Example 4

634.20 g DMAc, 32.72 g PPD (100 mol%) as diamine component, 7.06 g (8 mol%) BPDA as acid dianhydride component, 50.49 g (32 mol%) BPADA and 39.68 g (60 mol%) PMDA Except that, a polyimide film having a thickness of 38㎛ was prepared in the same manner as in Example 1.

Example 5

633.69 g of DMAc, 22.79 g (70 mole%) of PPD as a diamine component, 18.00 g (30 mole%) of DPE, 7.06 g (8 mole%) of BPDA as an acid dianhydride, 37.48 g (24 mole%) of BPADA and PMDA A polyimide film having a thickness of 38 μm was prepared in the same manner as in Example 1, except that 44.47 g (68 mol%) was used.

Comparative Example 1

634.41 g of DMAc, 25.60 g (70 mol%) of PPD as the diamine component, 20.40 g (30 mol%) of DPE, and 39.69 g (40 mol%) of BPDA and 44.25 g (60 mol%) of PMDA as the acid dianhydride component Except that, a polyimide film having a thickness of 38㎛ was prepared in the same manner as in Example 1.

Comparative Example 2

632.65 g of DMAc, 17.39 g (60 mol%) of PPD as a diamine component, 21.40 g (40 mol%) of DPE, and 35.10 g (60 mol%) of PMDA and 55.69 g (40 mol%) of BPADA as an acid dianhydride component Except that, a polyimide film having a thickness of 38㎛ was prepared in the same manner as in Example 1.

Comparative Example 3

The method was carried out in the same manner as in Example 1, except that 634.70 g of DMAc, 62.20 g (100 mol%) of DPE as the diamine component, and 67.80 g (100 mol%) of PMDA as the acid dianhydride component were used. A polyimide film was prepared.

Comparative Example 4

634.88 g DMAc, 8.21 g PPD (30 mole%) and DPE 35.60 g (70 mole%) as diamine component, BPDA 59.68 g (80 mole%) and BPADA 26.55 g (20 mole%) as acid dianhydride Except that, a polyimide film having a thickness of 38㎛ was prepared in the same manner as in Example 1.

Test Example 1

The polyamide films prepared in Examples 1 to 5 and Comparative Examples 1 to 4 were further heat treated at 320 ° C. for 10 minutes under no tension, and then various performances were evaluated by the following methods, and the results are shown in Table 1 below. Indicated.

(1) Tensile modulus

It was measured according to the method of ASTM D882 using an Instron UTM instrument.

(2) coefficient of thermal expansion

A TA of TMA-2940 was used to apply a load of 0.05 N, and the mixture was heated at room temperature to 400 ° C. at a temperature rising rate of 10 ° C. per minute, left for 5 minutes, and then cooled to 30 ° C. at a temperature dropping rate of 10 ° C. per minute. At this time, the coefficient of thermal expansion of the 50 ℃ to 200 ℃ section in the cooling process was measured.

(3) moisture absorption rate

The polyimide film was dried at 150 ° C. for 30 minutes and weighed (Ww1). Then, the film was treated with a constant temperature and humidity chamber for 24 hours under the condition of 23 ° C. and 99% RH. The water droplets on the surface of the film thus treated were wiped and weighed again (Ww2). The moisture absorption rate was computed by following formula (1) from the measured Ww1 and Ww2.

Hygroscopicity (%) = [(Ww2-Ww1) / Ww1] × 100

(4) Hygroscopic expansion coefficient

The length of the polyimide film was measured after leaving it for 24 hours at 23 degreeC and 20% RH conditions (L1). The film was left to stand at 23 ° C. and 80% RH for 24 hours, and then its length (L 2) was measured to calculate the hygroscopic expansion coefficient according to Equation 2 below.

(5) alkali reduction rate

The polyimide film was dried at 150 ° C. for 30 minutes and its weight was measured (Wa1). Subsequently, the film was completely immersed in 5 wt% aqueous NaOH solution and left at 55 ° C. for 4 hours. The treated film was rinsed in flowing distilled water for 5 minutes to completely remove NaOH remaining on the surface, and dried again in an oven at 150 ° C. for 30 minutes, and the weight thereof was measured (Wa2). From the measured Wa1 and Wa2, the alkali reduction ratio was measured by the following equation (3). Alkali loss ratio generally has a negative value, and as the number decreases, alkali resistance is poor.

Alkali weight loss (%) = [(Wa2-Wa1) / Wa1] × 100

From the results in Table 1, it can be seen that the polyimide film prepared in the example according to the present invention has excellent physical properties as compared with the polyimide film according to the comparative example.

Examples 6-10 and Comparative Examples 5-8: Preparation of Two-Layer Flexible Copper Clad Laminate (FCCL)

By using the polyimide film obtained in Examples 1 to 5 and Comparative Examples 1 to 4, a two-layer flexible copper foil laminate (FCCL) was manufactured by the following method.

First, the surface of the polyimide film was subjected to a reduced pressure plasma treatment under an oxygen and argon atmosphere, and then vacuum sputtered using nickel and chromium alloys. Then, the substrate was vacuum sputtered again with copper as a target to prepare a substrate having a metal layer adhered thereto. At this time, the thickness of the metal layer was fixed at 2500 kPa. The obtained deposited film was again electroplated to prepare a two-layer FCCL plated with copper finally having 8 μm ± 1 μm.

The two-layer FCCL thus prepared was etched to form a pattern having a circuit width of 1 mm and a space width of 1.5 mm.

Test Example 2

The properties of the two-layer FCCL prepared by the methods of Examples 6 to 10 and Comparative Examples 5 to 8 were measured according to the following methods, and the results are shown in Table 2 below.

(1) metal adhesion

① Room temperature peel strength: 90 ° peel strength was measured at room temperature according to the method of IPC TM 650 2.4.9, and the average value was taken 10 times.

(2) Pressure Cooker Test (PCT) Peeling Strength: The prepared circuit was treated at 120 ° C., 100% RH, and 2 atmospheres for 96 hours, and then 90 ° peel strength was measured 10 times according to the above method, and the average was taken.

(2) flex resistance

The manufactured circuits were mounted on a MIT-DA tester manufactured by Toyo Seiki Co., Ltd., and a bending angle was measured by applying a bending angle of ± 135 ° and a load of 200 g. The number of bendings was measured until a disconnection occurred, and the average was measured 10 times.

(3) dimensional change rate after etching

The length before circuit fabrication in the designated section of the prepared FCCL was measured (Le1). Thereafter, the FCCL was etched to manufacture a circuit, and the length of the previously designated section was measured again (Le2) to calculate the dimensional change rate after etching according to the following equation (4).

% Change in Dimensions after Etching = [(Le2-Le1) / Le1] × 100

(4) Curl

The prepared FCCL was cut into a size of 10 cm × 10 cm and heat-treated at 400 ° C. for 30 seconds to simulate the FPCB manufacturing process or the mounting process. The sample was placed on a flat bottom and the height of its end floating from the bottom was measured. The smaller the result of the curl measurement, the smaller the better.

From the results of Table 2, FCCL using a polyimide film excellent in elastic modulus, thermal expansion coefficient, moisture absorption rate, moisture absorption expansion coefficient and alkali resistance prepared in Examples according to the present invention is superior to the film according to the comparative example, It can be seen that the flex resistance, the dimensional change rate after etching, and the curl are shown.

As described above, the polyimide film according to the present invention satisfies high modulus of elasticity, low thermal expansion coefficient, low moisture absorption rate, low moisture absorption coefficient and excellent alkali resistance at the same time, and has excellent metal adhesion, bending resistance, and etching when applied to electronic materials. Since it shows the dimensional change rate and curl after, it can be usefully used in the field of electronic components.

Claims (8)

2,2'-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride as the aromatic acid dianhydride component A polyimide film comprising from 30 to 100 mol% in the dianhydride component and containing from 50 to 100 mol% of all diamine components as the aromatic diamine component. The method of claim 1, The molar ratio of the 2,2'-bis (4- (3,4-dicarboxyphenoxy) phenyl) propane dianhydride and the 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride is 6:94 to 80 It is 20: The polyimide film characterized by the above-mentioned. The method of claim 1, As the acid dianhydride component, pyromellitic dianhydride, 4,4'-oxydiphthalic dianhydride, 3,4,3 ', 4'-benzophenone tetracarboxylic dianhydride, 3,4,3', 4 ' -Diphenylsulfone tetracarboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 1,4,5 , 8-naphthalene tetracarboxylic dianhydride, 3,4,9,10-perylene tetracarboxylic dianhydride, polyimide, characterized in that it further comprises at least one aromatic acid dianhydride component selected from the group consisting of film. The method of claim 1, 4,4'- diamino diphenyl propane, 4,4'- diamino diphenyl methane, benzidine, 4,4'- diamino diphenyl ether, 3,3'- diamino diphenyl sulfone as said diamine component , 4,4'-diaminodiphenyl sulfone, 4,4'-bis (4-aminophenoxy) diphenyl sulfone, 4,4'-bis (3-aminophenoxy) diphenyl sulfone, 3,6- Thioxanthenediamine-10,10-dioxide, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ether, 3,4'-diamino Diphenyl ether, 1,5-diamino naphthalene, 2,6-diaminonaphthalene, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2'-bis (4- (4-aminophenoxy C) phenyl) propane, 4,4'-diaminodiphenyl diethyl silane, 4,4'-diaminodiphenyl silane, 4,4'-diaminodiphenyl ethyl phosphine oxide, metaphenylenediamine, Orthophenylenediamine, 1,3-bis (4-aminofe NOXY) A polyimide film further comprising at least one aromatic diamine component selected from the group consisting of benzene and derivatives thereof. The method of claim 1, Tensile modulus of the film is 4.5 to 9.0GPa, polyimide film, characterized in that the thermal expansion coefficient of 10 to 25ppm / ℃ in the temperature range of 50 ℃ to 200 ℃. The method of claim 1, When the film is left at 99% RH for 24 hours at room temperature, the moisture absorption rate is 2.0% by weight or less, and the moisture absorption coefficient in the 80% RH section at 23 ° C. and 20% RH is 20 ppm /% RH or less. Polyimide film. The method of claim 1, The alkali reduction rate when the said film is processed by 55 degreeC 5weight% NaOH aqueous solution for 4 hours is 5 weight% or less, The polyimide film characterized by the above-mentioned. An electronic device component comprising the polyimide film according to any one of claims 1 to 7.