JP4876890B2 - Copper plate - Google Patents

Description

   The present invention relates to a copper-clad board suitable as a material for flexible printed wiring boards, COF, TAB, etc. used in the field of electrical and electronic equipment. More specifically, the present invention relates to a polyimide film as a base material and copper on one or both sides. This relates to a copper-clad plate having a small dimensional change rate after etching.

  Printed wiring boards are widely used in electronic and electrical equipment. Among them, a flexible printed wiring board that can be bent is widely used in bent portions of personal computers and mobile phones, and in portions that require bending such as hard disks. As a material for such a flexible printed wiring board, a copper-clad board using various polyimide films is usually used.

A typical example of a polyimide film used for a copper-clad board is a polyimide film using pyromellitic dianhydride as an acid dianhydride component and 4,4′-diaminodiphenyl ether as a diamine component. Such a polyimide film has a structure with an excellent balance between mechanical and thermal properties, and is widely used industrially as a general-purpose product. However, the polyimide film composed of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether has the advantage that it is easy to bend, but it is too soft and the base material is bent when mounting a semiconductor, resulting in poor bonding. Had a point. In addition, polyimide film consisting of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether has a large coefficient of thermal expansion (CTE) and hygroscopic expansion coefficient (CHE), and a high water absorption rate. There is a problem that the change is large, and when the fine wiring is formed, the intended wiring width and wiring cannot be formed.
In order to solve such a problem, a method of forming a flexible printed wiring board using a substrate having a small dimensional change other than a polyimide film, such as a liquid crystal film (for example, see Patent Document 1), etc. has been disclosed. The liquid crystal film is inferior in heat resistance to the polyimide film, and has a problem that the base material is deformed during soldering. Especially in recent years, lead-free solders that do not use lead have spread due to environmental problems, but since most of the lead-free solders have a higher melting point than lead-containing solders, the problem of liquid crystal film substrate deformation has become more serious. It was.
JP 2005-297405 A

  Accordingly, an object of the present invention is to solve the problems of both dimensional change and heat resistance of the flexible printed wiring board, enable the formation of fine wiring, and for a flexible printed wiring board that does not deform even when lead-free solder is used. It is to provide a copper-clad board.

The present invention adopts the following configuration in order to achieve the above object.
(1) Formed from paraphenylenediamine and 4,4′-diaminodiphenyl ether as the diamine component, and pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as the acid dianhydride component With a modulus of elasticity of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. of 5 to 20 ppm / ° C., a humidity expansion coefficient of 25 ppm /% RH or less, a water absorption of 3% or less, and a heat shrinkage at 200 ° C. for 1 hour. Is a copper-clad plate having a copper plate via an adhesive on one or both sides of a polyimide film having a 0.10% or less, and the dimensional change rate after etching the entire surface is -0.10% to 0.00. Copper-clad plate that is in the range of 10% .
(2) Formed from paraphenylenediamine and 4,4′-diaminodiphenyl ether as the diamine component, and pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as the acid dianhydride component With a modulus of elasticity of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. of 5 to 20 ppm / ° C., a humidity expansion coefficient of 25 ppm /% RH or less, a water absorption of 3% or less, and a heat shrinkage at 200 ° C. for 1 hour. Is a copper-clad plate having a copper plate without an adhesive on one or both sides of a polyimide film having a 0.10% or less, and the dimensional change rate after etching the entire surface is -0.10% to 0 Copper-clad plate that is within 10% range .
(3) Formed from paraphenylenediamine and 4,4′-diaminodiphenyl ether as the diamine component, and pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride as the acid dianhydride component With a modulus of elasticity of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. of 5 to 20 ppm / ° C., a humidity expansion coefficient of 25 ppm /% RH or less, a water absorption of 3% or less, and a heat shrinkage at 200 ° C. for 1 hour. One side of the polyimide film having a 0.10% or less is a copper-clad plate having a copper plate with an adhesive and the other side having a copper plate without an adhesive. Is a copper-clad board in the range of -0.10% to 0.10% .
(4) The diamine component of the polyimide film is 10-50 mol% paraphenylenediamine and 50-90 mol% 4,4'-diaminodiphenyl ether, and the acid dianhydride component is pyromellitic dianhydride 50-99 mol%. And the copper-clad board in any one of (1)-(3) which is 1-50 mol% of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride.
(5) The adhesive is composed of at least one selected from an epoxy adhesive, an acrylic adhesive, and a polyimide adhesive, (1) or any one of (3) to ( 4 ), Copper-clad board.
(6) The copper-clad plate according to any one of (1) or (3) to ( 5 ), which is a copper foil having a copper surface roughness (Rz) of 0.1 to 10 μm .

  According to the present invention, it is possible to provide a copper-clad board useful as a material for a flexible printed wiring board that can form fine wiring and does not deform even when lead-free solder is used.

  The copper-clad plate of the present invention uses a polyimide film as a base material and has a copper plate on one side or both sides of this polyimide film.

  Here, as the polyimide film of the base material, paraphenylenediamine and 4,4′-diaminodiphenyl ether as diamine components, pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyl as acid dianhydride components It is a polyimide film made of tetracarboxylic dianhydride. That is, four types of paraphenylenediamine, 4,4′-diaminodiphenyl ether, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride are essential components, and only these four types are included. Or it is a polyimide film obtained by adding a small amount of another component in addition to these four types. Preferably, 10 to 50 mol% paraphenylenediamine and 50 to 90 mol% 4,4'-diaminodiphenyl ether are used as the diamine component, and 50 to 99 mol% pyromellitic dianhydride as the acid dianhydride component and It is a polyimide film using 1 to 50 mol% of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride. More preferably, the elastic modulus is 3 to 7 GPa, the linear expansion coefficient at 50 to 200 ° C. is 5 to 20 ppm / ° C., the humidity expansion coefficient is 25 ppm /% RH or less, the water absorption is 3% or less, and 200 ° C. for 1 hour. It is a polyimide film having a heat shrinkage of 0.10% or less. If the amount of paraphenylenediamine is too large, it becomes hard, and if it is too small, it is too soft, so 1 to 70 mol% is preferable, more preferably 5 to 60 mol%, and more preferably 10 to 50 mol%. When the amount of 4,4'-diaminodiphenyl ether is too much, it becomes soft, and when it is too little, it becomes hard, so 20 to 99 mol% is preferable, 40 to 95 mol% is more preferable, and 50 to 90 mol% is more preferable. When there is too much pyromellitic dianhydride, it becomes hard, and when it is too little, it becomes soft, so 50 to 99 mol% is preferable, 60 to 90 mol% is more preferable, and 65 to 85 mol% is more preferable. The amount of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride becomes soft when it is too much, and it becomes hard when it is too little, so 1-50 mol% is preferable, more preferably 10-40 mol%, more preferably Is 15 to 35 mol%. The elastic modulus, which is an index of hardness, is preferably in the range of 3 to 7 GPa. If it exceeds 7 GPa, it is too hard and if it is less than 3 GPa, it is too soft. The linear expansion coefficient is preferably 5 to 20 ppm / ° C., and if it exceeds 20 ppm / ° C., the dimensional change due to heat is too large, and if it is smaller than 5 ppm / ° C., the difference from the linear expansion coefficient with the metal used for the wiring increases. Therefore, warping occurs. When the humidity expansion coefficient exceeds 25 ppm /% RH, the dimensional change due to humidity is too large. Therefore, the humidity expansion coefficient is preferably 25 ppm /% RH or less. If the water absorption rate exceeds 3%, the dimensional change of the film becomes large due to the influence of the sucked water, so 3% or less is preferable. When the heat shrinkage rate at 200 ° C. for 1 hour exceeds 0.10%, the dimensional change due to heat becomes large, so the heat shrinkage rate is preferably 0.10% or less.

The polymerization method may be carried out by any known method, for example: (1) First, the aromatic diamine component is added to the solvent first, and then the aromatic tetracarboxylic acid component is added to the equivalent amount of the aromatic diamine component. To polymerize.

  (2) A method in which the total amount of the aromatic tetracarboxylic acid component is first put in a solvent, and then the aromatic diamine component is added in an amount equivalent to that of the aromatic tetracarboxylic acid component for polymerization.

  (3) After one aromatic diamine compound is put in a solvent, the aromatic tetracarboxylic acid compound is mixed at a ratio of 95 to 105 mol% with respect to the reaction components, and then mixed for the other time. A method in which an aromatic diamine compound is added, and then an aromatic tetracarboxylic acid compound is added and polymerized so that the total aromatic diamine component and the total aromatic tetracarboxylic acid component are approximately equal.

  (4) After putting the aromatic tetracarboxylic acid compound in the solvent, the aromatic tetracarboxylic acid compound is mixed for a time required for the reaction at a ratio of 95 to 105 mol% of one aromatic diamine compound with respect to the reaction component, and then the aromatic tetracarboxylic acid compound is mixed. A method in which a carboxylic acid compound is added, and then the other aromatic diamine compound is added and polymerized so that the total aromatic diamine component and the total aromatic tetracarboxylic acid component are approximately equal.

  (5) A polyamic acid solution (A) is prepared by reacting one aromatic diamine component and an aromatic tetracarboxylic acid in a solvent so that either one becomes excessive, and the other aromatic diamine in another solvent. The polyamic acid solution (B) is prepared by reacting the component and the aromatic tetracarboxylic acid so that either one becomes excessive. A method of mixing the polyamic acid solutions (A) and (B) thus obtained to complete the polymerization. At this time, when adjusting the polyamic acid solution (A), if the aromatic diamine component is excessive, the polyamic acid solution (B) contains excessive aromatic tetracarboxylic acid component, and the polyamic acid solution (A) contains aromatic tetracarboxylic acid. When the acid component is excessive, the polyamic acid solution (B) makes the aromatic diamine component excessive, and the polyamic acid solutions (A) and (B) are combined to form the wholly aromatic diamine component and wholly aromatic compound used in these reactions. Adjustment is made so that the amount of the tetracarboxylic acid component is approximately equal.

  The polymerization method is not limited to these, and other known methods may be used.

  In the present invention, specific examples of the organic solvent used for forming the polyamic acid solution include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide, N, N-dimethylformamide, N, N-diethylformamide and the like. Formamide solvents, N, N-dimethylacetamide, acetamide solvents such as N, N-diethylacetamide, pyrrolidone solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, phenol, o-, Examples thereof include phenolic solvents such as m- or p-cresol, xylenol, halogenated phenol and catechol, or aprotic polar solvents such as hexamethylphosphoramide and γ-butyrolactone, and these may be used alone or as a mixture. It is desirable to use But further xylene, the use of aromatic hydrocarbons such as toluene are also possible.

  The polyamic acid solution thus obtained contains a solid content of 5 to 40% by weight, preferably 10 to 30% by weight, and its viscosity is 10 to 2000 Pa · s as measured by a Brookfield viscometer, preferably 100-1000 Pa · s is preferably used for stable liquid feeding. Moreover, the polyamic acid in the organic solvent solution may be partially imidized.

  Next, the manufacturing method of the polyimide film of this invention is demonstrated.

  As a method for forming a polyimide film, a polyamic acid solution is cast into a film and thermally decyclized and desolvated to obtain a polyimide film, and a polyamic acid solution is mixed with a cyclization catalyst and a dehydrating agent. The method of obtaining a polyimide film by preparing a gel film by decyclizing it and heating it to remove the solvent is preferable, but the latter is preferable because the thermal expansion coefficient of the obtained polyimide film can be kept low. .

  Furthermore, various fillers such as silica and alumina may be added for the purpose of improving the slipperiness of the film. As the particle size of the filler to be used, it is preferable to use those having an average particle size of 0.1 to 1 μm. If the average particle size is less than 0.1 μm, the slipperiness of the film is poor, and if the average particle size exceeds 1 μm, many agglomerates are present during film production. Furthermore, if a filler having an average particle size of more than 1 μm is used, the number of protrusions with a size of 20 μm or more on the film surface is more than 10/5 cm × 5 cm, and the number of protrusions with a height of 2 μm or more is more than 3/5 cm × 5 cm. End up. Due to the presence of protrusions of this size, it is not preferable because the filler straddles between the wirings and causes conduction failure, and it becomes easy to cause a problem of breaking through the film thickness of the photoresist mask.

  As a copper foil used for the copper plate which has an adhesive agent in a copper-clad board, what is the copper foil whose surface roughness (Rz) of the copper by the side of adhesion is 0.1-10 micrometers is preferable. If the surface roughness is greater than this, when the flexible printed wiring board is used in the high-frequency signal region, current does not easily flow due to the skin effect, making it difficult to use in the high-frequency region. The surface roughness (Rz) mentioned here is Rz defined in 5.1 “Definition of 10-point average roughness” in JIS B 0601-1994 “Definition and display of surface roughness”.

  Although it does not specifically limit about the thickness of a polyimide film, Preferably it is 5-125 micrometers, More preferably, it is 9-75 micrometers, More preferably, it is 11-55 micrometers. When it is too thick, it becomes easy to cause winding slip when it is made into a roll, and when it is too thin, wrinkles and the like are likely to enter.

  A copper plate is formed on one or both sides of the polyimide film as described above via an adhesive or without an adhesive. When the adhesive is used, the adhesive is preferably at least one selected from an epoxy adhesive, an acrylic adhesive, and a polyimide adhesive. These adhesives may be provided with various rubbers, plasticizers, curing agents, phosphorus-based flame retardants, and other various additives for the purpose of imparting flexibility. Further, as the resin component of the polyimide-based adhesive, thermoplastic polyimide is often used, but thermosetting polyimide may be used. Moreover, you may use a thermoplastic polyimide film as an adhesive as a polyimide-type adhesive agent.

  The rate of dimensional change after the entire etching of the copper-clad board is preferably in the range of −0.10% to 0.10%, more preferably − in order not to cause a problem in mounting as a flexible printed wiring board. It is preferably in the range of 0.05% to 0.05%, more preferably -0.03% to 0.03%.

  Hereinafter, specific examples will be described. In addition, although the polyimide film used by the Example uses what was formed into a film by the method of the synthesis examples 1-6, it is not limited to these. Moreover, what was formed into a film by the synthesis examples 7-8 is used for the polyimide film used by Comparative Examples 1-2. Furthermore, as the adhesive used in the examples, those prepared in Synthesis Examples 9 to 10 are used, but are not limited thereto.

  Moreover, each characteristic of the polyimide film obtained by the synthesis example and the copper-clad board of an Example was evaluated with the following method.

(1) Film thickness It measured as follows using the Mitutoyo lightmatic (Series318) thickness meter. That is, 15 points were selected arbitrarily from the entire surface of the film, the thicknesses were measured at these 15 points, and the average was calculated to obtain the thickness.

(2) Linear expansion coefficient A TMA-50 thermomechanical analyzer manufactured by Shimadzu Corporation was used, and measurement was performed under conditions of a measurement temperature range of 50 to 200 ° C and a temperature increase rate of 10 ° C / min. The load was 0.25 N, and the temperature was first raised from 35 ° C. at 10 ° C./min to 300 ° C. Hold at 300 ° C. for 5 minutes, then lower the temperature at 10 ° C./minute to lower the temperature to 35 ° C., hold at 35 ° C. for 30 minutes, then raise the temperature at 10 ° C./minute to raise the temperature to 300 ° C. It was. The data at the time of the second temperature increase from 35 ° C. to 300 ° C. was read, and the linear expansion coefficient was calculated from the average of the portion of 50 to 200 ° C.

(3) Elastic modulus RTM-250 Tensilon universal testing machine manufactured by A & D was used and measured under the condition of tensile speed: 100 mm / min. Load cell 10Kgf, measurement accuracy ± 0.5% full scale, measure stress-strain curve, slope of straight line of rising part of stress-strain curve (calculated by least square method between 2N to 15N), initial Calculation was performed as follows from the sample length, the sample width, and the sample thickness.
Elastic modulus = (Slope of straight line portion × initial sample length) / (sample width × sample thickness)

(4) Humidity expansion coefficient At 25 ° C, a film was mounted in a TM7000 furnace manufactured by ULVAC, dried air was fed into the furnace and dried for 2 hours, and then the TM7000 furnace was supplied with air from an HC-1 type steam generator. Was humidified to 90% RH, and the coefficient of humidity expansion was determined from the dimensional change during that period. The humidification time was 7 hours. The data from 3RH% to 90RH% was read, and the humidity expansion coefficient was calculated from the average of the portion of 3 to 90RH%.

(5) Water absorption rate It left still in the desiccator of 98% RH atmosphere for 2 days, and evaluated by the weight increase with respect to the weight at the time of drying.

(6) Heat shrinkage rate A film of 20 cm × 20 cm was prepared, and the film size (L1) after being left in a room adjusted to 25 ° C. and 60% RH for 2 days was measured, followed by heating at 200 ° C. for 60 minutes. Thereafter, the film size (L2) was measured after being left in a room adjusted to 25 ° C. and 60% RH for 2 days, and evaluated by the following formula calculation.
Heat shrinkage rate = − [(L2−L1) / L1] × 100

(7) Dimensional change rate The dimensional change rate before and after etching the copper-clad plate was measured using a CNC image processing measurement system (manufactured by Nikon Corporation, NEXIV VMR-3020) under conditions of a temperature of 25 ° C. and a humidity of 60%. Field of view: 1.165mm x 0.875mm (4x) The distance between the centers of 6mmφ circular masking tape circled on the surface of the copper-clad plate with a spacing of 210mm in the MD direction before and after etching the entire copper surface It was performed by measuring and calculating. The distance before etching is L3, the distance after etching is L4, and before and after copper etching, the sample is left overnight under conditions of temperature 25 ° C and humidity 60% to eliminate the influence of polyimide water absorption. To do. The dimensional change rate was calculated by the following formula using an average value of values obtained by measuring the distance between two points five times.
Dimensional change rate (%) = [(L3-L4) / L3] × 100

(Synthesis Example 1)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) / 4,4′-diaminodiphenyl ether (molecular weight 200.24) / Paraphenylenediamine (molecular weight 108.14) is prepared in a molar ratio of 65/35/80/20, polymerized in a 18.5 wt% solution in DMAc (N, N-dimethylacetamide), and polyamic acid Got. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a 100 ° C. stainless steel drum rotated from a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.20 mm. This gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, and 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 25 μm. The physical properties are shown in Table 1.

(Synthesis Example 2)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) / 4,4′-diaminodiphenyl ether (molecular weight 200.24) / Paraphenylenediamine (molecular weight 108.14) is prepared in a molar ratio of 65/35/80/20, polymerized in a 18.5 wt% solution in DMAc (N, N-dimethylacetamide), and polyamic acid Got. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a 100 ° C. stainless steel drum rotated by a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.30 mm. This gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, and 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 38 μm. The physical properties are shown in Table 1.

(Synthesis Example 3)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) // 4,4′-diaminodiphenyl ether (molecular weight 200.24 ) / Paraphenylenediamine (molecular weight 108.14) in a molar ratio of 3/1/3/1, prepared as a 18.5 wt% solution in DMAc (N, N-dimethylacetamide), and polymerized. The acid was obtained. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a 100 ° C. stainless steel drum rotated from a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.20 mm. This gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, and 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 25 μm. The physical properties are shown in Table 1.

(Synthesis Example 4)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) / 4,4′-diaminodiphenyl ether (molecular weight 200.24) / Paraphenylenediamine (molecular weight 108.14) is prepared in a molar ratio of 4/1/4/1 and polymerized in a 18.5 wt% solution in DMAc (N, N-dimethylacetamide) to form a polyamic acid Got. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a stainless steel drum rotated at 100 ° C. from a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.10 mm. The gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 12.5 μm. . The physical properties are shown in Table 1.

(Synthesis Example 5)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) / 4,4′-diaminodiphenyl ether (molecular weight 200.24) / Paraphenylenediamine (molecular weight 108.14) is prepared in a molar ratio of 9/1/8/2, polymerized to a 18.5 wt% solution in DMAc (N, N-dimethylacetamide), and polyamic acid Got. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a 100 ° C. stainless steel drum rotated by a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.07 mm. This gel film was peeled off from the drum, both ends thereof were gripped, and treated in a heating furnace at 200 ° C. × 30 seconds, 350 ° C. × 30 seconds, 550 ° C. × 30 seconds to obtain a 9 μm-thick polyimide film. The physical properties are shown in Table 1.

(Synthesis Example 6)
Pyromellitic dianhydride (molecular weight 218.12) / 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (molecular weight 294.22) / 4,4′-diaminodiphenyl ether (molecular weight 200.24) / Paraphenylenediamine (molecular weight 108.14) is prepared in a molar ratio of 3/2/3/2, polymerized to a 18.5 wt% solution in DMAc (N, N-dimethylacetamide), and polyamic acid Got. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a stainless steel drum at 100 ° C. rotated by a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.05 mm. This gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, and 550 ° C. for 30 seconds to obtain a 6 μm thick polyimide film. The physical properties are shown in Table 1.

(Synthesis Example 7)
Pyromellitic dianhydride (molecular weight 218.12) / 4,4′-diaminodiphenyl ether (molecular weight 200.20) is mixed in a molar ratio of 50/50 to obtain DMF (N, N-dimethylformamide) 18. Polymerization was performed with a 5% by weight solution to obtain a polyamic acid. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a 100 ° C. stainless steel drum rotated from a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.20 mm. This gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, and 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 25 μm. The physical properties are shown in Table 1.

(Synthesis Example 8)
Pyromellitic dianhydride (molecular weight 218.12) / C (molecular weight 200.20) was mixed at a molar ratio of 50/50 to obtain a DMF (N, N-dimethylformamide) 18.5% by weight solution. Polymerization gave a polyamic acid. A conversion agent consisting of acetic anhydride (molecular weight 102.09) and isoquinoline was mixed and stirred at a ratio of 50% by weight to the polyamic acid solution. At this time, it prepared so that acetic anhydride and isoquinoline might be 2.0 and 0.4 molar equivalent with respect to the amic acid group of a polyamic acid, respectively. The obtained mixture was cast on a stainless steel drum rotated at 100 ° C. from a T-shaped slit die to obtain a gel film having a self-supporting property of 55% by weight of residual volatile components and a thickness of about 0.10 mm. The gel film was peeled off from the drum, and both ends thereof were gripped and treated in a heating furnace at 200 ° C. for 30 seconds, 350 ° C. for 30 seconds, 550 ° C. for 30 seconds to obtain a polyimide film having a thickness of 12.5 μm. . The physical properties are shown in Table 1.

(Synthesis Example 9)
50 parts by weight of epoxy resin “Epicoat” 834 manufactured by Yuka Shell Co., Ltd., 100 parts by weight of phosphorus-containing epoxy resin FX279BEK75 manufactured by Tohto Kasei Co., Ltd., 6 weights of curing agent 4,4′-DDS manufactured by Sumitomo Chemical Co., Ltd. Part, JSR Co., Ltd. NBR (PNR-1H) 100 parts by weight, Showa Denko Co., Ltd. 30 parts by weight aluminum hydroxide was stirred and mixed with methyl isobutyl ketone 600 parts by weight at 30 ° C. to obtain an adhesive solution. .

(Synthesis Example 10)
50 parts by weight of epoxy resin “Epicoat” 828 manufactured by Yuka Shell Co., Ltd., 80 parts by weight of phosphorus-containing epoxy resin FX279BEK75 manufactured by Tohto Kasei Co., Ltd., 6 weights of curing agent 4,4′-DDS manufactured by Sumitomo Chemical Co., Ltd. Part, JSR Co., Ltd. NBR (PNR-1H) 100 parts by weight, Showa Denko Co., Ltd. aluminum hydroxide 10 parts by weight with methyl isobutyl ketone 600 parts by stirring at 30 ° C. to obtain an adhesive solution. .

Example 1
Using the polyimide film formed in Synthesis Example 1, the adhesive of Synthesis Example 9 was applied to one side of the polyimide film and dried by heating at 150 ° C. for 5 minutes to form an adhesive layer having a dry film thickness of 10 μm. Lamination temperature of this polyimide film with single-sided adhesive and 1/2 ounce copper foil (F0-WS18, manufactured by Furukawa Circuit Foil Co., Ltd.) having a surface roughness (Rz) of 1.5 μm using a hot roll laminator. Thermal lamination was performed at 160 ° C., a lamination pressure of 196 N / cm (20 kgf / cm), and a lamination speed of 1.5 m / min to produce a single-sided flexible copper-clad plate. When the dimensional change rate before and after the copper entire surface etching was measured using the obtained copper-clad plate, the dimensional change rate was 0.010%.

(Example 2)
A single-sided copper-clad plate was produced in the same manner as in Example 1 except that the polyimide film formed in Synthesis Example 5 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was 0.015%.

(Example 3)
A single-sided copper-clad board was produced in the same manner as in Example 1 except that the polyimide film formed in Synthesis Example 4 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was 0.002%.

Example 4
A single-sided copper-clad plate was produced in the same manner as in Example 1 except that the polyimide film formed in Synthesis Example 6 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was 0.048%.

(Example 5)
After using the polyimide film formed in Synthesis Example 2 and setting the vacuum chamber to an ultimate pressure of 1 × 10 −3 Pa, nickel / chrome = 95/5 (weight ratio) by DC magnetron sputtering at an argon gas pressure of 1 × 10 −1 Pa. The Nichrome alloy (1) was sputtered on one side to a thickness of 5 nm, and copper was further sputtered to a thickness of 50 nm. Next, a copper layer having a thickness of 6 μm was laminated by electrolytic plating using a copper sulfate bath under the condition of a current density of 2 A / dm 2 to prepare a single-sided copper-clad plate. The composition of the copper sulfate bath was a solution in which an appropriate amount of additives was added to copper sulfate pentahydrate 80 g / liter, sulfuric acid 200 g / liter, and hydrochloric acid 50 mg / liter. When the dimensional change rate before and after the copper entire surface etching was measured using the obtained copper-clad plate, the dimensional change rate was 0.008%.

(Example 6)
The polyimide film formed in Synthesis Example 3 was used, and the adhesive of Synthesis Example 10 was applied to both surfaces of the polyimide film, followed by heat drying at 150 ° C. for 5 minutes to form an adhesive layer having a dry film thickness of 10 μm. This polyimide film with a double-sided adhesive and a 1/2 ounce copper foil (F0-WS18, manufactured by Furukawa Circuit Foil Co., Ltd.) having a surface roughness (Rz) of 1.5 μm are laminated using a hot roll laminator. Thermal lamination was performed at 160 ° C., a lamination pressure of 196 N / cm (20 kgf / cm), and a lamination speed of 1.5 m / min to produce a double-sided copper-clad plate. Using the obtained double-sided copper-clad plate, the dimensional change rate before and after etching the entire copper surface was measured, and the dimensional change rate was -0.008%.

(Example 7)
The polyimide film formed in Synthesis Example 2 was used, the vacuum chamber was brought to an ultimate pressure of 1 × 10 −3 Pa, and then nickel / chrome = 90/10 (weight ratio) by DC magnetron sputtering at an argon gas pressure of 1 × 10 −1 Pa. The Nichrome alloy of 2) was sputtered on both sides to a thickness of 3 nm, and copper was further sputtered to a thickness of 10 nm. Next, a copper layer having a thickness of 5 μm was laminated by electrolytic plating using a copper sulfate bath under the condition of a current density of 2 A / dm 2 to prepare a double-sided copper-clad plate. The composition of the copper sulfate bath was a solution in which an appropriate amount of additives was added to copper sulfate pentahydrate 80 g / liter, sulfuric acid 200 g / liter, and hydrochloric acid 50 mg / liter. Using the obtained double-sided copper-clad plate, the dimensional change rate before and after etching the entire copper surface was measured, and the dimensional change rate was 0.005%.

(Example 8)
After using the polyimide film formed in Synthesis Example 6 and setting the vacuum chamber to an ultimate pressure of 1 × 10 −3 Pa, nickel / chromium = 90/10 (weight ratio) by DC magnetron sputtering at an argon gas pressure of 1 × 10 −1 Pa. The Nichrome alloy (1) was sputtered on one side to a thickness of 3 nm, and copper was further sputtered to a thickness of 10 nm. Next, a copper layer having a thickness of 12 μm was laminated by electrolytic plating using a copper sulfate bath under the condition of a current density of 2 A / dm 2 to prepare a single-sided flexible copper-clad plate. The composition of the copper sulfate bath was a solution in which an appropriate amount of additives was added to copper sulfate pentahydrate 80 g / liter, sulfuric acid 200 g / liter, and hydrochloric acid 50 mg / liter. Using the obtained single-sided copper-clad plate, the adhesive of Synthesis Example 8 was applied to the opposite surface (polyimide surface) of the surface on which the copper layer was formed, and heat-dried at 150 ° C. for 5 minutes, and the dry film thickness was 10 μm. An adhesive layer was formed. Lamination temperature of one-sided copper-clad plate with adhesive and 1/3 ounce copper foil (F0-WS12, manufactured by Furukawa Circuit Foil Co., Ltd.) having a surface roughness (Rz) of 1.5 μm using a hot roll laminator. Heat lamination is performed under the conditions of 160 ° C., laminating pressure of 196 N / cm (20 kgf / cm), laminating speed of 1.5 m / min, copper is formed on one side with an adhesive and the other side without an adhesive. Obtained double-sided copper-clad board. Using the obtained double-sided copper-clad plate, the dimensional change rate before and after etching the entire copper surface was measured, and the dimensional change rate was -0.052%.

(Comparative Example 1)
A single-sided copper-clad board was produced in the same manner as in Example 1 except that the polyimide film formed in Synthesis Example 7 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was -0.122%.

(Comparative Example 2)
A single-sided copper-clad board was produced in the same manner as in Example 1 except that the polyimide film formed in Synthesis Example 8 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was -0.132%.

(Comparative Example 3)
A double-sided copper-clad board was produced in the same manner as in Example 8 except that the polyimide film formed in Synthesis Example 7 was used. When the dimensional change rate before and after the copper entire surface etching was measured, the dimensional change rate was -0.105%.

  Table 2 summarizes the dimensional change rates of Examples 1 to 8 and Comparative Examples 1 to 3.

  According to the present invention, it is possible to provide a copper-clad board suitable for a flexible wiring board having excellent dimensional stability and heat resistance.

Claims (6)

Formed from p-phenylenediamine and 4,4'-diaminodiphenyl ether as the diamine component, pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride as the acid dianhydride component , elastic The linear expansion coefficient at a rate of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. is 5 to 20 ppm / ° C., a humidity expansion coefficient is 25 ppm /% RH or less, a water absorption is 3% or less, and a heat shrinkage rate at 200 ° C. for 1 hour is 0. It is a copper-clad plate having a copper plate with an adhesive on one or both sides of a polyimide film that is 10% or less, and the dimensional change rate after etching the entire surface is -0.10% to 0.10%. Copper-clad plate that is within range . Formed from p-phenylenediamine and 4,4'-diaminodiphenyl ether as the diamine component, pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride as the acid dianhydride component , elastic The linear expansion coefficient at a rate of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. is 5 to 20 ppm / ° C., a humidity expansion coefficient is 25 ppm /% RH or less, a water absorption is 3% or less, and a heat shrinkage rate at 200 ° C. for 1 hour is 0. It is a copper-clad plate having a copper plate on one or both sides of a polyimide film that is 10% or less without an adhesive, and the dimensional change rate after etching the entire surface is -0.10% to 0.10%. Copper-clad plate that is within the range of Formed from p-phenylenediamine and 4,4'-diaminodiphenyl ether as the diamine component, pyromellitic dianhydride and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride as the acid dianhydride component , elastic The linear expansion coefficient at a rate of 3 to 7 GPa, a linear expansion coefficient at 50 to 200 ° C. is 5 to 20 ppm / ° C., a humidity expansion coefficient is 25 ppm /% RH or less, a water absorption is 3% or less, and a heat shrinkage rate at 200 ° C. for 1 hour is 0. One side of the polyimide film that is 10% or less is a copper-clad plate that has a copper plate through an adhesive, and the other side is a copper plate without an adhesive, and the dimensional change rate after the entire etching is − A copper-clad plate within a range of 0.10% to 0.10% . The diamine component of the polyimide film is 10-50 mol% paraphenylenediamine and 50-90 mol% 4,4'-diaminodiphenyl ether, the acid dianhydride component is 50-99 mol% pyromellitic dianhydride and 3, The copper-clad plate according to any one of claims 1 to 3, which is 1 to 50 mol% of 3 ', 4,4'-biphenyltetracarboxylic dianhydride. Adhesive epoxy adhesive, copper clad laminate according to claim 1 or claim 3-4, characterized in that it consists of at least one selected from acrylic adhesives, and polyimide adhesives. The copper-clad plate according to any one of claims 1 and 3 to 5 , which is a copper foil having a surface roughness (Rz) of copper on the adhesion side of 0.1 to 10 µm .