JP2004042579A - Copper-clad laminated sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-clad laminated sheet suitable as an all polyimide substrate material, which can cope with a fine pattern formation which can not be achieved by a conventional and publicized copper-clad laminated sheet for a substrate. <P>SOLUTION: An ultrathin copper plating with a heat resistance carrier and a heat press bondable multilayer polyimide film comprising a heat press bondable aromatic polyimide layer and an aromatic polyimide layer high in heat resistance are heat press bonded, cooled and laminated under pressure, to obtain the copper-clad laminated sheet having a bonding strength of not less than 0.7 N/mm between the copper plating and the heat press bondable multilayer polyimide film and a peeling strength of not more than 0.2 N/mm between the carrier and the copper plating. Then, the lamination is executed by heat press bonding, cooling and laminating at a temperature from the glass transition of the heat press bondable aromatic polyimide to 400°C under pressure by a double belt press. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a copper-clad laminate and a method for producing the same, and more particularly, has a large adhesive strength despite using an extremely thin copper foil, has a good product appearance, and is suitable as a substrate material. Copper-clad laminates.
[0002]
[Prior art]
Aromatic polyimide films are widely used for electronic devices such as cameras, personal computers, and liquid crystal displays.
In order to use an aromatic polyimide film as a substrate material for a flexible printed board (FPC) or a tape-automated bonding (TAB), a copper foil is laminated using an adhesive such as an epoxy resin. The method has been adopted.
[0003]
It has been pointed out that aromatic polyimide films are excellent in heat resistance, mechanical strength, electrical properties, and the like, but are inferior in properties of polyimide due to poor heat resistance of adhesives.
In order to solve such a problem, copper was electroplated on a polyimide film without using an adhesive, a polyamic acid solution was applied to a copper foil, dried, imidized, or thermoplastic polyimide was thermocompressed. All-polyimide substrates have been developed.
However, the metal foil laminate of all-polyimide obtained by these methods has a low adhesive strength or a large adhesive strength, but it is difficult to obtain a wide and long product. It has been pointed out that imidization takes a long time and productivity is poor.
[0004]
Also, a polyimide laminate in which a polyimide adhesive is sandwiched between a polyimide film and a metal foil is known (US Pat. No. 4,543,295).
However, this polyimide laminate has a problem that it cannot be used for a biphenyltetracarboxylic acid-based polyimide film having a low linear thermal expansion because of its low adhesive strength.
[0005]
For this reason, a method of using a metal having a specific hardness as a material of the laminating roll in the roll laminating method or a method of using a polyimide obtained by using a specific aromatic diamine as a thermocompression bonding polyimide Has been proposed.
However, it has been difficult to obtain a copper-clad laminate having high adhesive strength by using this polyimide laminate and its manufacturing method.
[0006]
On the other hand, there is a great demand for fine patterns, and copper foils having a thickness of about 12 μm have begun to be used.
However, even with such improvements, it is difficult to respond to demands for further fine patterning.
For this reason, a laminated board obtained by forming a base metal layer on a polyimide film in advance by vapor deposition or sputtering and copper plating of a predetermined thickness by copper plating, or an ultra-thin with no carrier or with a carrier using an organic bonding agent Attempts have been made to laminate copper foil to polyimide film, but the resulting copper-clad laminate has problems such as low adhesive strength, foaming of the copper-clad substrate, and peeling during heating in the post-process. I have.
[0007]
[Problems to be solved by the invention]
It is an object of the present invention to reduce the adhesive strength by using an ultra-thin copper foil to enable fine patterning, which was impossible with a conventionally known copper-clad laminate for a substrate. An object of the present invention is to provide a copper-clad laminate suitable as a substrate material of all-polyimide, which has solved problems such as generation of foaming and peeling during heating.
[0008]
[Means for Solving the Problems]
That is, the present invention provides a thermocompression bonding multilayer polyimide film comprising an ultrathin copper foil with a heat-resistant carrier, a thermocompression-bondable aromatic polyimide layer and a high heat-resistance aromatic polyimide layer, which is thermocompression-pressed and cooled. A copper-clad laminate having an adhesion strength between a copper foil and a thermocompression-bondable multilayer polyimide film of 0.7 N / mm or more and a peel strength between a carrier and the copper foil of 0.2 N / mm or less. .
[0009]
In addition, the present invention, under ultra-thin copper foil with a heat-resistant carrier and a thermocompression-bondable aromatic polyimide layer and a thermocompression-bondable multilayer polyimide film composed of a high heat-resistance aromatic polyimide layer under pressure by a double belt press, The present invention relates to a method for producing the above-mentioned copper-clad laminate, in which thermocompression bonding and cooling are performed at a temperature not lower than the glass transition temperature of the thermocompression-bonding aromatic polyimide and not higher than 400 ° C. and cooling.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the present invention will be listed below.
1) The above-mentioned copper-clad laminate, wherein the ultra-thin copper foil with a heat-resistant carrier is obtained by laminating ultra-thin copper foils having a thickness of 1 to 7 µm.
2) The above copper-clad laminate, wherein the thermocompression-bondable multilayer polyimide film has a thickness of 7 to 50 µm.
3) A thermocompression-bondable multilayer polyimide film is obtained by laminating and integrating a thermocompression-bondable aromatic polyimide layer on at least one surface of a highly heat-resistant aromatic polyimide layer by a coextrusion-cast film forming method. The above copper clad laminate.
[0011]
Examples of the configuration of the copper-clad laminate of the present invention include the following combinations.
In the following description, TPI-F indicates a thermocompression-bondable multilayer polyimide film.
(1) Ultra-thin copper foil with heat-resistant carrier / TPI-F
(2) Ultra-thin copper foil with heat-resistant carrier / TPI-F / metal foil or ceramic foil
(3) Ultra-thin copper foil with heat-resistant carrier / TPI-F / TPI / ultra-thin copper foil with heat-resistant carrier
[0012]
In the present invention, it is necessary to use an ultra-thin copper foil with a heat-resistant carrier. Examples of the ultra-thin copper foil carrier with a heat-resistant carrier include those made of a metal-based, ceramic-based heat-resistant bonding agent and a metal such as a copper foil having a thickness of about 20 to 35 μm, It is preferable that the thickness of the ultra-thin copper foil is 3 to 5 μm.
[0013]
Specific examples of the ultra-thin copper foil with a heat-resistant carrier include, for example, an ultra-thin copper foil (XTF: 5 μm / 35 μm in thickness, 3 μm / 35 μm in thickness, all of which are ultra-thin copper foil / carrier Copper foil) and ultra-thin copper foil (F-CP: thickness 5 μm / 35 μm, thickness 3 μm / 35 μm, all ultra-thin copper foil / carrier copper foil) manufactured by Furukawa Electric Co., Ltd.
[0014]
The thermocompression-bondable multilayer polyimide film in the present invention is obtained by laminating a thermocompression-bondable aromatic polyimide precursor solution on one or both sides of a high heat-resistant aromatic polyimide precursor (also referred to as polyamic acid) solution dried film. Later, or preferably, after laminating a thermocompression-bondable aromatic polyimide precursor solution on one or both sides of a highly heat-resistant aromatic polyimide precursor solution by co-extrusion-casting film forming method, drying, imide To obtain a thermocompression-bondable multilayer polyimide film.
[0015]
As the thermocompression-bondable aromatic polyimide constituting the thermocompression-bondable multilayer polyimide film, any thermoplastic aromatic polyimide that can be thermocompression-bonded at a temperature of about 300 to 400 ° C. may be used. Preferably, 1,3-bis (4-aminophenoxybenzene) (hereinafter sometimes abbreviated as TPER) and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride (hereinafter a- BPDA).
Further, as the thermocompression-bondable aromatic polyimide, 1,3-bis (4-aminophenoxy) -2,2-dimethylpropane (DANPG) and 4,4′-oxydiphthalic dianhydride (ODPA) are used. Manufactured from.
Alternatively, it is produced from 4,4′-oxydiphthalic dianhydride (ODPA) and pyromellitic dianhydride and 1,3-bis (4-aminophenoxybenzene).
Alternatively, 1,3-bis (3-aminophenoxy) benzene and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride or 3,3′-diaminobenzophenone and 1,3-bis ( Prepared from 3-aminophenoxy) benzene and 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride.
Further, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (hereinafter may be simply abbreviated as s-BPDA) ), 1,3-bis (4-aminophenoxybenzene), and 4,4′-diaminodiphenyl ether (hereinafter may be simply abbreviated as DADE).
[0016]
Other tetracarboxylic dianhydrides such as 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and 2,2-bis (3 , 4-dicarboxyphenyl) propane dianhydride and the like.
Further, other diamines such as 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylmethane, and 2,4,4′-diaminodiphenyl ether within a range that does not impair the physical properties of the thermocompression-bondable aromatic polyimide. 2-bis (4-aminophenyl) propane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenyl) diphenyl ether, 4,4'-bis (4- Aminophenyl) diphenylmethane, 4,4'-bis (4-aminophenoxy) diphenylether, 4,4'-bis (4-aminophenoxy) diphenylmethane, 2,2-bis [4- (aminophenoxy) phenyl] It may be replaced by an aromatic diamine having multiple benzene rings, such as propane.
Dicarboxylic acids, such as phthalic acid and its substituted products, such as hexahydrophthalic acid and its substituted products, in order to block the amine end of the thermocompression-bondable aromatic polyimide, particularly when phthalic anhydride is used. Good.
[0017]
The aromatic polyimide having high heat resistance in the thermocompression-bondable multilayer polyimide film is preferably 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and para-phenylenediamine (hereinafter simply abbreviated as PPD). In some cases) and optionally 4,4'-diaminodiphenyl ether and / or pyromellitic dianhydride (hereinafter sometimes abbreviated simply as PMDA). In this case, the PPD / DADE (molar ratio) is preferably from 100/0 to 85/15. Further, s-BPDA / PMDA is preferably from 100: 0 to 50/50.
[0018]
A high heat-resistant aromatic polyimide is produced from pyromellitic dianhydride, paraphenylenediamine and 4,4'-diaminodiphenyl ether. In this case, DADE / PPD (molar ratio) is preferably from 90/10 to 10/90.
Furthermore, high heat-resistant aromatic polyimides include 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) and paraphenylenediamine (PPD) and 4 , 4'-diaminodiphenyl ether (DADE). In this case, it is preferable that BTDA in the acid dianhydride is 20 to 90 mol%, PMDA is 10 to 80 mol%, PPD in the diamine is 30 to 90 mol%, and DADE is 10 to 70 mol%.
Other kinds of aromatic tetracarboxylic dianhydrides and aromatic diamines such as 4,4'-diaminodiphenylmethane may be used as long as the physical properties of the high heat-resistant aromatic polyimide are not impaired.
Further, a substituent such as a fluorine group, a hydroxyl group, a methyl group or a methoxy group may be introduced into the aromatic ring of the aromatic tetracarboxylic dianhydride or the aromatic diamine.
[0019]
As the high heat-resistant aromatic polyimide, those which cannot be confirmed at a glass transition temperature of about less than about 340 ° C. in the case of a single-layer polyimide film are preferable, and particularly have a linear expansion coefficient (50 to 200 ° C.). ) (MD, TD and any of their averages) is 5 × 10 ^-6 ~ 25 × 10 ^-6 Those having a cm / cm / ° C are preferred.
In the synthesis of this highly heat-resistant aromatic polyimide, if the proportion of each component is finally within the above range, random polymerization, block polymerization, blending, or synthesis of two or more kinds of polyamic acid solutions in advance to prepare each polyamic acid This is achieved by any method of mixing an acid solution to obtain a copolymer by recombination of a polyamic acid.
[0020]
The organic solvent used to obtain the above polyamic acid is N-methyl-2-pyrrolidone, N, N-dimethylformamide for both high heat-resistant aromatic polyimide and thermocompression-bondable aromatic polyimide. , N, N-dimethylacetamide, N, N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam, cresols and the like. These organic solvents may be used alone or in combination of two or more.
[0021]
For the purpose of limiting the gelling of the polyamic acid, a phosphorus-based stabilizer such as triphenyl phosphite, triphenyl phosphate or the like is used in an amount of 0.01 to 1% based on the solid content (polymer) concentration at the time of polyamic acid polymerization. Can be added. Further, a basic organic compound-based catalyst can be added to the dope solution for the purpose of accelerating imidization. For example, imidazole, 2-imidazole, 1,2-dimethylimidazole, 2-phenylimidazole, or the like is used in an amount of 0.01 to 20% by weight, especially 0.5% by weight based on polyamic acid (solid content). It can be used in a proportion of up to 10% by weight. These are used to form a polyimide film at a relatively low temperature and to prevent imidization from becoming insufficient.
[0022]
In the production of the thermocompression-bondable multilayer polyimide film, preferably, a co-extrusion-casting film forming method, for example, a thermocompression-bondable aromatic film is applied to one or both surfaces of a polyamic acid solution to give the high heat-resistant aromatic polyimide. A method of coextruding a polyamic acid solution to give an aromatic polyimide, casting and applying the solution on a support surface such as a stainless steel mirror surface, a belt surface, or the like, and setting it in a semi-cured state at 100 to 200 ° C. or a dried state before it can be adopted. . When the cast film is processed at a high temperature exceeding 200 ° C., defects such as a decrease in adhesiveness tend to occur in the production of a thermocompression-bondable multilayer polyimide film. The semi-cured state or a state before that means that it is in a self-supporting state by heating and / or chemical imidization.
[0023]
The co-extrusion of a polyamic acid solution giving an aromatic polyimide with high heat resistance and a polyamic acid solution giving an aromatic polyimide with thermocompression bonding is described, for example, in Japanese Patent Application Laid-Open No. 3-180343 (JP-B-7-102661). The co-extrusion method described in the above) can be applied to a two- or three-layer extrusion die and cast on a support.
On one or both sides of the extrudate layer giving the high heat-resistant aromatic polyimide, a polyamic acid solution giving the thermocompression-bondable aromatic polyimide is laminated to form a multilayer film-like material, dried, and then heat-pressed. Is heated to a temperature not higher than the temperature at which degradation occurs above the glass transition temperature (Tg) of the aromatic polyimide, preferably 300 to 400 ° C. (surface temperature measured by a surface thermometer) (preferably this temperature). Drying for 1 to 60 minutes) and imidization to produce a thermocompression-bondable multilayer polyimide film having a thermocompression-bondable aromatic polyimide on one or both sides of a high heat-resistant (substrate layer) aromatic back polyimide. be able to.
[0024]
The thermocompression-bondable aromatic polyimide constituting the thermocompression-bondable multilayer polyimide according to the present invention has a glass transition temperature of 180 to 275 ° C, particularly 200 to 275 ° C by using the acid component and the diamine component. Preferably, it is obtained by drying and imidizing under the above-mentioned conditions and substantially not causing gelation of the thermocompression-bondable aromatic polyimide. Preferably, the elastic modulus does not change and the elastic modulus at 275 ° C. is about 0.0002 to 0.2 times the elastic modulus at a temperature around room temperature (50 ° C.).
[0025]
In the present invention, the thickness of the thermocompression-bondable aromatic polyimide layer constituting the thermocompression-bondable multilayer polyimide is preferably 0.5 to 10 μm, particularly preferably about 1 to 8 μm. If it is less than 0.5 μm, the adhesive performance is reduced, and if it exceeds 10 μm, it can be used, but there is no particular effect, and rather the heat resistance of the copper clad laminate decreases.
In the present invention, the thickness of the high heat-resistant (substrate layer) polyimide layer constituting the thermocompression-bondable multilayer polyimide is preferably 5 to 50 μm, particularly preferably 5 to 40 μm. If the thickness is less than 5 μm, problems arise in mechanical strength and dimensional stability of the formed thermocompression-bondable multilayer polyimide film.
The thermocompression-bondable multilayer polyimide film preferably has a thickness of 7 to 50 μm, particularly preferably 7 to 50 μm. If the thickness is less than 7 μm, it is difficult to handle the prepared film, and if the thickness is more than 50 μm, it is disadvantageous to obtain a fine pattern.
[0026]
According to the co-extrusion-casting film forming method, a high heat-resistant aromatic polyimide layer and one or both sides of the thermocompression-bondable aromatic polyimide are cured at a relatively low temperature to form a thermocompression-bondable aromatic layer. The imidization and drying of the self-supporting film can be completed without deteriorating the group-III polyimide, and a thermocompression-bonding multilayer polyimide film having good electric properties and adhesive strength can be obtained.
[0027]
In the present invention, the ultra-thin copper foil with a heat-resistant carrier and the thermocompression-bonding multilayer polyimide film, and optionally, the ultra-thin copper foil with a heat-resistant carrier of the same type or a metal foil of a different kind are introduced into a double belt press. Preferably, it is preheated to about 150 to 250 ° C. in-line just before introduction, heated to high temperature under cooling and cooled, and laminated and integrated to obtain a copper-clad laminate.
[0028]
Further, the temperature of the thermocompression zone of the double belt press is higher than the glass transition temperature of the thermocompression-bonding aromatic polyimide by 20 ° C. or more and 400 ° C. or less, particularly the temperature of 30 ° C. or higher and 400 ° C. or less than the glass transition temperature. Thermocompression bonding under pressure, followed by cooling under pressure in a cooling zone, preferably to a temperature lower than the glass transition temperature of the thermocompression-bondable polyimide by 20 ° C. or more, particularly 30 ° C. or more. It is preferable to obtain a copper-clad laminate.
[0029]
In the above method, when using a thermocompression-bonding multi-layer polyimide film having a three-layer structure and laminating it with one layer of an ultra-thin copper foil with a single-sided heat-resistant carrier, a highly heat-resistant film that is easily peelable, for example, Rz is 2 μm Less heat-resistant film, preferably a polyimide film (Ube Industries, U-PILEX S), a high heat-resistant resin film such as a fluororesin film, a rolled copper foil, etc., having low surface roughness and low surface smoothness May be interposed between the thermocompression-bonding polyimide layer and the heat-resistant carrier surface of another heat-resistant ultra-thin copper foil with a carrier as a protective material. After lamination, this protective material may be removed from the laminate and rolled up, or may be rolled up with the protective material laminated and removed at the time of use.
[0030]
In the present invention, the ultra-thin copper foil with a heat-resistant carrier and a thermocompression-bonding multilayer polyimide film comprising a thermocompression-bonding aromatic polyimide layer and a high heat-resistance aromatic polyimide layer are heated under pressure by a double belt press, and then heat-treated. The thermocompression bonding at a temperature of 400 ° C. or lower and the glass transition temperature of the aromatic polyimide is higher than the glass transition temperature by cooling and laminating, so that the adhesive strength between the copper foil and the thermocompression multilayer polyimide film is 0.7 N / mm or more. The copper-clad laminate has a peel strength between the carrier and the copper foil of 0.2 N / mm or less, preferably 0.1 N / mm or less, and has such a good appearance that substantially no foaming is observed on the surface of the heat-resistant carrier. You can get a board.
[0031]
The copper-clad laminate of the present invention may be cut to a predetermined size as it is or after being subjected to various processes such as roll winding, etching, and, if necessary, curling, and then cut to a predetermined size. Can be used as
For example, it can be suitably used as a substrate for FPC, TAB, multilayer FPC, or flex-rigid substrate.
Further, a single-sided copper foil laminate (having a total thickness of 15 to 10 μm), in which the thickness of the ultrathin copper foil from which the heat-resistant carrier has been removed is 1 to 7 μm, particularly 3 to 5 μm, and the thickness of the thermocompression-bondable multilayer polyimide film layer is 7 to 50 μm. 27 μm) or a double-sided copper foil laminate (having a total thickness of 25 to 40 μm), or an epoxy adhesive or a heat-resistant polyimide adhesive such as thermoplastic polyimide, thermoplastic polyamideimide, or polyimidesiloxane-epoxy. By bonding a plurality of copper foil laminates with an adhesive (thickness of 5 to 50 μm, preferably 5 to 15 μm, especially 7 to 12 μm), the copper foil laminate has 2 to 10 layers, and has high heat resistance, low water absorption, and low heat resistance. A multilayer substrate that satisfies the dielectric constant and high electrical characteristics can be suitably obtained.
The copper-clad laminate of the present invention includes not only a long one but also a long one cut into a predetermined size as described above.
[0032]
The copper-clad laminate of the present invention is used as a circuit board after the heat-resistant carrier is peeled off and subjected to a known etching step and heating step, which are known per se.
Examples of the etching step include a method of etching a copper foil of a copper-clad laminate at room temperature with an etching solution such as an aqueous ferric chloride solution. In the heating step, for example, the copper-clad laminate from which the heat-resistant carrier has been peeled off is immersed in a solder bath at 280 ° C. for about 10 seconds, or is laminated with another copper-clad laminate with a heat-resistant adhesive. Thermocompression bonding to form a multilayer substrate.
[0033]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
In each of the following examples, physical properties were evaluated according to the following methods.
Coefficient of linear thermal expansion: 50-200 ° C, measured at 5 ° C / min (average value of TD and MD), cm / cm / ° C
Glass transition temperature (Tg): measured from viscoelasticity.
Adhesive strength: 90 ° peel strength was measured at a rate of 50 mm / min for a sample having a width of 10 mm with the copper thickness further increased by about 10 μm by thick plating.
Peel strength: The 90 ° peel strength between the carrier copper foil and the ultra-thin copper foil was measured at a rate of 50 mm / min for a 10 mm wide sample.
Product appearance: The appearance of the product after lamination was evaluated by visually determining the presence or absence of blisters due to foaming.
○: good without foaming, △: foaming partially, × foaming all over
Comprehensive evaluation: ○ is good, △ is slightly good, × is bad
[0034]
Synthetic example 1 of dope for producing aromatic polyimide with high heat resistance
N-Methyl-2-pyrrolidone was added to a reaction vessel equipped with a stirrer and a nitrogen inlet tube, and paraphenylenediamine and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride were further added at 1000: 998. At a molar ratio of 18% (% by weight, the same applies hereinafter). After completion of the addition, the reaction was continued for 3 hours while maintaining the temperature at 50 ° C. The obtained polyamic acid solution was a brown viscous liquid, and the solution viscosity at 25 ° C. was about 1500 poise. This solution was used as a dope.
[0035]
Synthesis of thermo-compression dope for producing aromatic polyimide-1
N-Methyl-2-pyrrolidone was added to a reaction vessel equipped with a stirrer and a nitrogen inlet tube, and 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 '-Biphenyltetracarboxylic dianhydride, 1,3-bis (4-aminophenoxy) benzene and 4,4'-diaminodiphenyl ether in a molar ratio of 20: 80: 50: 50 having a monomer concentration of 22. % And triphenyl phosphate was added at 0.1% based on the monomer weight. After completion of the addition, the reaction was continued for 1 hour while maintaining the temperature at 25 ° C. This polyamic acid solution had a solution viscosity at 25 ° C. of about 2000 poise. This solution was used as a dope.
[0036]
Reference Example 1
Using a film forming apparatus provided with a three-layer extrusion die (multi-manifold type die), the above-mentioned high heat-resistant aromatic polyimide dope and thermocompression-bondable aromatic polyimide dope were formed. The thickness of the dice was changed, the mixture was cast on a metal support, and continuously dried with hot air at 140 ° C. to form a solidified film. After the solidified film is peeled from the support, the temperature is gradually raised from 200 ° C. to 320 ° C. in a heating furnace to remove the solvent and imidize, and the following two types of thermocompression-bondable three-layer extruded polyimide films are wound. It was wound on a take-up roll.
This thermocompression-bondable three-layer extruded polyimide film exhibited the following physical properties.
[0037]
1) Thermo-compressible multilayer polyimide film
Thickness configuration: 4 μm / 17 μm / 4 μm (total 25 μm)
Tg of thermocompression bonding aromatic polyimide: 261 ° C
Thermal expansion coefficient (50 to 200 ° C): 19 × 10 ^-6 × cm / cm / ℃
Volume resistance: 5 × 10 ^Fifteen Ω · cm
2) Thermo-compression multilayer polyimide film-2
Thickness configuration: 5 μm / 28 μm / 5 μm (total 38 μm)
Tg of thermocompression bonding aromatic polyimide: 265 ° C
Thermal expansion coefficient (50-200 ° C): 20 × 10 ^-6 × cm / cm / ℃
Volume resistance: 6 × 10 ^Fifteen Ω · cm
[0038]
Example 1
A thermocompression-bonding three-layer extruded polyimide film-1 and two X-Rin XTFs (ultra-thin copper foil thickness 5 μm / carrier copper foil thickness 35 μm) as ultra-thin copper foil with heat-resistant carrier. After being preheated, the temperature of the heating zone (maximum heating temperature) is 330 ° C. (set), the temperature of the cooling zone (minimum cooling temperature) is 117 ° C.), and the pressing pressure is 40 kg /. cm ² The compression bonding time was 2 minutes, and the layers were continuously laminated under pressure and thermocompression under cooling to obtain a rolled product as a copper-clad laminate (width: about 530 mm, the same applies hereinafter).
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 0.9 N / mm
Carrier copper foil peel strength: 0.00N / mm
Overall rating: ○
[0039]
Example 2
Copper-clad in the same manner as in Example 1 except that XTF (thickness of ultra-thin copper foil: 3 μm / thickness of carrier copper foil: 35 μm) manufactured by Orin was used as the ultra-thin copper foil with a heat-resistant carrier. A roll wound material as a laminate (width: about 530 mm, the same applies hereinafter) was obtained.
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 1.0 N / mm
Carrier copper foil peel strength: 0.00N / mm
Overall rating: ○
[0040]
Example 3
A roll-wound copper-clad laminate (width: about 530 mm, the same applies hereinafter) in the same manner as in Example 1 except that a thermocompression-bonded three-layer extruded polyimide film-2 was used as the thermocompression-bonded multilayer polyimide film. I got something.
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 0.9 N / mm
Carrier copper foil peel strength: 0.00N / mm
Overall rating: ○
[0041]
Example 4
Except for using F-CP (5 μm in thickness of ultra-thin copper foil / 35 μm in thickness of carrier copper foil) manufactured by Furukawa Electric Co., Ltd. as ultra-thin copper foil with heat-resistant carrier, A roll-wound material which is a copper-clad laminate (width: about 530 mm, the same applies hereinafter) was obtained.
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 0.9 N / mm
Carrier copper foil peel strength: 0.05 N / mm
Overall rating: ○
[0042]
Example 5
Except for using F-CP (thickness of ultra-thin copper foil 3 μm / thickness of carrier copper foil 35 μm) made by Furukawa Electric Co., Ltd. as ultra-thin copper foil with heat-resistant carrier, A roll-wound material which is a copper-clad laminate (width: about 530 mm, the same applies hereinafter) was obtained.
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 0.9 N / mm
Carrier copper foil peel strength: 0.04 N / mm
Overall rating: ○
[0043]
Example 6
Using a thermocompression-bonded three-layer extruded polyimide film-2 as a thermocompression-bonded multilayer polyimide film, F-CP manufactured by Furukawa Electric Co., Ltd. (thickness of ultra-thin copper foil 5 μm / carrier) A roll-wound material as a copper-clad laminate (width: about 530 mm, the same applies hereinafter) was obtained in the same manner as in Example 1 except that a copper foil thickness of 35 μm was used.
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: ○
Adhesive strength: 0.8 N / mm
Carrier copper foil peel strength: 0.06 N / mm
Overall rating: ○
[0044]
Comparative Example 1
A copper-clad laminate (width: 5 mm) was used in the same manner as in Example 1 except that MT35S-H manufactured by Mitsui Kinzoku Kogyo KK (thickness of only ultra-thin copper foil was 5 μm) was used as the copper foil, and the crimping temperature was 320 ° C. 530 mm, the same applies hereinafter).
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: × (strong foam)
Adhesive strength: 0.8 N / mm
Overall rating: ×
[0045]
Comparative Example 2
A copper clad laminate (width: 5 mm) was used in the same manner as in Example 1 except that MT35S-H manufactured by Mitsui Kinzoku Kogyo KK (thickness of only ultra-thin copper foil was 5 μm) was used as the copper foil, and the crimping temperature was 340 ° C. 530 mm, the same applies hereinafter).
The evaluation results of the obtained copper-clad laminate are shown below.
Product appearance: × (strong foam)
Adhesive strength: 0.8 N / mm
Overall rating: ×
[0046]
The copper foil carrier is peeled off from the copper-clad laminate having the ultra-thin copper foil with the copper foil carrier obtained in Examples 1 to 6 on both sides by a rewinding machine, and etched with ferric chloride using a dry film. As a result, a fine wire having a pitch of 40 μm could be formed.
[0047]
【The invention's effect】
According to the present invention, the following effects are achieved because of the configuration described above.
According to the present invention, it is possible to obtain a copper-clad laminate having a large adhesive strength, a good appearance and an ultra-thin copper foil, which can cope with fine-line pattern etching. In particular, a copper-clad laminate effective for fine-line wiring having a pitch of 40 μm or less can be obtained. A laminate can be obtained.
Further, according to the present invention, the above-mentioned copper-clad laminate can be easily obtained.

Claims (5)

A thermocompression-bonded multi-layer polyimide film composed of an ultra-thin copper foil with a heat-resistant carrier, a thermocompression-bondable aromatic polyimide layer and a high heat-resistance aromatic polyimide layer, and thermocompression-compressed under pressure-cooled and laminated. A copper clad laminate having an adhesive strength between the copper foil and the thermocompression-bondable multilayer polyimide film of 0.7 N / mm or more and a peel strength between the carrier and the copper foil of 0.2 N / mm or less. The copper-clad laminate according to claim 1, wherein the ultra-thin copper foil with a heat-resistant carrier is obtained by laminating an ultra-thin copper foil having a thickness of 1 to 7 µm. The copper-clad laminate according to claim 1, wherein the thermocompression-bondable multilayer polyimide film has a thickness of 7 to 50 μm. The thermocompression-bondable multilayer polyimide film is obtained by laminating and integrating a thermocompression-bondable aromatic polyimide layer on at least one surface of a high heat-resistant aromatic polyimide layer by a coextrusion-cast film forming method. The copper-clad laminate according to any one of 1 to 3, above. A thermocompression-bondable aromatic polyimide layer composed of an ultra-thin copper foil with a heat-resistant carrier and a thermocompression-bondable aromatic polyimide layer and a high heat-resistance aromatic polyimide layer and a thermocompression-bonded multi-layer polyimide film is pressed by a double belt press to form a thermocompression-bondable aromatic film. The method for producing a copper-clad laminate according to claim 1, wherein the laminate is formed by thermocompression bonding and cooling at a temperature not lower than the glass transition temperature of the polyimide and not higher than 400 ° C.