JP2003192789A - Heat-bondable polyimide and laminate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-bondable polyimide having a high peeling strength from an SUS foil (strainless steel foil) and good chemical etchability and to provide a laminate using the polyimide. <P>SOLUTION: There are provided a heat-bondable polyimide having imide units represented by the formula [wherein Ar<SB>1</SB>s are such that, based on 100 mol% tetracarboxylic acid dianhydride residues, pyromellitic acid dianhydride residues amount to 12-25 mol%, 3,3'4,4'-benzophenonetetracarboxylic acid dianhydride residues amount to 5-15 mol%, and 3,3'4,4'-biphenyltetracarboxylic acid dianhydride residues amount to the balance; and Ar<SB>2</SB>is an amine residue essentially consisting of 1,3-bis(4-aminophenoxy)benzene] and can give an observable endothermic melting peak as measured by DSC; a multilayer polyimide film using the heat-bondable polyimide; and a laminate of a metallic layer with the multilayer polyimide film. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-fusible polyimide, a multilayer polyimide film using the heat-fusible polyimide, and a laminate of a multi-layer polyimide film and a metal layer. It has good heat-sealing property with steel foil) and has good chemical etching characteristics such as short etching time when forming a pattern by chemical etching (wet etching with a chemical solution) and good pattern shape. The present invention relates to the heat-fusible polyimide and the laminate using the heat-fusible polyimide.

[0002]

2. Description of the Related Art Aromatic polyimide films have hitherto been widely used for electronic devices such as cameras, personal computers and liquid crystal displays. In order to use the aromatic polyimide film as a substrate material for flexible printed boards (FPC) and tape automated bonding (TAB), an adhesive such as epoxy resin is used to bond copper foil. The method has been adopted.

Aromatic polyimide films are excellent in heat resistance, mechanical strength, and electrical characteristics, but it is pointed out that the original characteristics of polyimide are impaired because the heat resistance of adhesives such as epoxy resins is poor. ing. In order to solve such problems, electroplating copper on a polyimide film without using an adhesive, applying a polyamic acid solution to a copper foil, drying, imidizing, or thermocompressing a thermoplastic polyimide All-polyimide base materials have also been developed.

Further, there is known a polyimide laminate in which a film-shaped polyimide adhesive is joined in a sandwich form between a polyimide film and a metal foil, and a method for producing the same. However, this polyimide laminate has a problem that its peeling strength (adhesive strength) is small and its use is limited. In order to solve these problems, a laminate by the casting method, a multilayer polyimide film and a metal foil laminate by the multilayer extrusion method have been proposed. Many problems have been solved by these, but in the heat-fusible polyimide having the composition used for the thin layer portion of these laminates, the original properties of the polyimide are impaired, and the heat-fusibility with the SUS foil is Is insufficient. Further, in order to improve the heat fusion property, an attempt to reduce the molecular weight or change the terminal group has been proposed, but on the contrary, the electrical characteristics may be deteriorated and the peel strength is not sufficiently large. The chemical etching property of the conductive polyimide layer has an etching rate of 0.7 μm.
/ Min (min), which is small and insufficient.

[0005]

[Patent Document 1] US Pat. No. 4,543,295 (Claim 1)

[Patent Document 2] Japanese Patent Publication No. 7-102648 (claim 1)

[Patent Document 3] Japanese Patent Application Laid-Open No. 10-138318 (claim 1)

[0006]

The object of the present invention is to provide S
The peel strength of a laminate obtained by heat-sealing a US foil (stainless steel foil) and a polyimide film with a heat-fusible polyimide layer is large, and the heat-fusible polyimide layer is etched by chemical etching when forming a pattern. It is an object of the present invention to provide a heat-fusible polyimide having a chemical etching property in which the time is short and the pattern shape is good, and a laminate using the polyimide.

[0007]

The present invention has the following formula:

[Chemical 2]

[Wherein, Ar ₁ is 100 mol% of tetracarboxylic acid dianhydride residue, 12 to 25 mol% is pyromellitic dianhydride residue, and 5 to 15 mol% is 3,3 ', 4. ，
4'-benzophenone tetracarboxylic dianhydride residue,
The rest is 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride residue, and Ar ₂ is an aromatic diamine residue containing 1,3-bis (4-aminophenoxy) benzene as an essential component. is there. ] Having an imide unit represented by
The present invention relates to a heat-fusible polyimide whose melting endothermic peak can be observed by measurement.

The present invention also relates to a multilayer polyimide film in which the thin polyimide layer (Y) made of the heat-fusible polyimide is laminated and integrated on at least one surface of the base polyimide layer (X). Further, the present invention is
The present invention relates to a laminate in which the above-mentioned multilayer polyimide film and a metal layer are laminated via the above-mentioned thin-layer polyimide (Y).

Further, according to the present invention, a copper foil or SUS (stainless steel) foil having a thickness of 3 to 35 μm / a thickness of 7 to 150 is used.
a multilayer polyimide layer in which a thin polyimide layer (Y) made of a heat-fusible polyimide is laminated and integrated on both surfaces of a base polyimide layer (X) made of a highly heat resistant polyimide having a thickness of 3 to 200 μm, It has a three-layer structure of stainless steel foil or stainless steel plate, and the heat fusible polyimide is DS
A melting endothermic peak can be observed by C measurement, and the multilayered polyimide layer has a tensile elastic modulus (MD, TD, 2
5 ° C.) is 400 to 1000 kgf / mm ² , preferably 6
0 to 1000 kgf / mm ² , especially 700 to 100
Chemical etching rate of 0 kgf / mm ² and 2.0 μm / min or more, and 90 degree peel strength on both sides of 0.8 kgf / cm or more, especially 1 kgf / cm
The present invention relates to the laminated body. In this specification, the chemical etching rate means an etching solution (composition: potassium hydroxide 36%) at 80 ° C. using a laminate in which a multilayer polyimide film and a stainless steel foil (about 20 μm) are attached
%, Monoethanolamine 37% by weight, water 27% by weight), the time required for the multilayer polyimide film to completely dissolve is measured, and the value obtained by the following formula is displayed. Etching rate (μm / min) = Polyimide film thickness (μm) /
Time required for complete dissolution (minutes)

[0011]

Preferred embodiments of the present invention will be listed below. 1) The melting endothermic peak was 340 to 38 by DSC measurement.
The above heat-fusible polyimide observable at 0 ° C. 2) The base polyimide layer (X) is 3,3 ', 4,4'-
A polyimide obtained from biphenyltetracarboxylic dianhydride and 100 to 10 mol% of p-phenylenediamine or 0 to 90 mol% of 4,4'-diaminodiphenylether, or 3,3 ', 4,4'- Biphenyltetracarboxylic dianhydride 0-100 mol%, pyromellitic dianhydride 100-0 mol%, p-phenylenediamine 10-90 mol% and 4,4'-diaminodiphenylether 90-10 mol% The above-mentioned multilayer polyimide film comprising a polyimide obtained from

3) In the lamination integration, after the polyamic acid solution for the base polyimide layer and the polyamic acid solution for the thin polyimide layer are co-extruded and laminated by the casting film forming method,
The above-mentioned multilayer polyimide film formed by heating and drying, and imidizing. 4) Lamination integration is a thin coating of a thin layer polyamic acid solution that provides a thin layer polyimide (Y) on at least one side of a self-supporting film formed from a base layer polyamic acid solution that provides a base polyimide (X). Then heat dried
The above-mentioned multilayer polyimide film formed by imidization. 5) Lamination is a thin layer polyimide of a multilayer polyimide film
The above laminate, which is obtained by stacking the (Y) layer and the metal foil, and then thermocompression bonding. 6) The above laminate, wherein the metal foil has a thickness of 3 to 35 μm.

The heat-fusible polyimide of the present invention comprises the above-mentioned imide unit, and the melting endothermic peak can be observed by DSC measurement, and preferably the melting endothermic peak is 340 to 3.
It can be observed at 80 ° C.

With respect to the ratio of each of the above imide units, pyromellitic dianhydride residues, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride residues, and 3,
When any of the 3 ', 4,4'-biphenyltetracarboxylic dianhydride residues is out of the above range, the peel strength on the SUS side of the laminate laminated with such a polyimide layer (25 ° C, 90 ° C). Less than 0.8 kgf / cm or the chemical etching rate is 2.0 cm
It is less than / min, which is not preferable.

The heat-fusible polyimide of the present invention is, for example, 12 to 25 mol% of pyromellitic dianhydride, 3,3 ',
4,4'-benzophenone tetracarboxylic acid dianhydride 5
˜15 mol%, and the balance of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (preferably 60 to 83).
Aromatic tetracarboxylic acid dianhydride consisting of
Aromatic diamines containing essentially equal amounts of 1,3-bis (4-aminophenoxy) benzene (preferably 50 mol% or more, particularly 70 mol% or more in aromatic diamine) as an essential component in an organic solvent. It can be obtained by polymerizing and heating at 120 to 400 ° C. for imidization.

When a multilayer polyimide film is obtained by using the above heat-fusible polyimide, the thin-layer polyimide composed of the heat-fusible polyimide has the above-mentioned components in an organic solvent,
The reaction is carried out at a temperature of about 100 ° C. or less, especially 20 to 60 ° C. to prepare a polyamic acid solution, and the polyamic acid solution or the polyamic acid solution is added with an organic solvent to adjust the polyamic acid concentration. The dope liquid film of the substrate polyimide or the self-supporting film of the substrate polyimide is used to form a thin film of the dope liquid at 50 to 400 ° C.
It can be formed by heating and drying for about 1 to 30 minutes to evaporate and remove the solvent from the thin film and to cyclize the polyamic acid with an imide. The concentration of polyamic acid in the polyamic acid dope that provides the thin-layer polyimide is preferably about 1 to 20% by weight.

In the present invention, the base polyimide is 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine and / or 4,
Polyimide obtained from 4'-diaminodiphenyl ether, or 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride or pyromellitic dianhydride and p
-Polyimides obtained from phenylenediamine and 4,4'-diaminodiphenyl ether.

As the base polyimide, in particular, the following formula

[Chemical 3]

[In the formula, m / n (molar ratio) = 100/0
70/30. ] A polyimide having an imide unit represented by the formula [1] is advantageous because it has a low linear expansion coefficient close to that of a circuit metal, particularly copper. In addition, it goes without saying that other types of polyimide can be similarly used as the polyimide that gives a polyimide film having a low linear expansion coefficient in the electronic technical field.

In the present invention, the multilayer polyimide film preferably has a thermocompression bonding property and a tensile modulus (MD, TDASTM-D882) of 400 kgf.
/ Mm ² or more and the thickness is preferably 7 to 150 μm. Further, the linear expansion coefficient (50 to 200 ° C.) (MD,
TD) is 30 × 10 ⁻⁶ cm / cm / ° C. or less, especially 15 ×
It is preferably 10 ⁻⁶ to 30 × 10 ⁻⁶ cm / cm / ° C.

The above-mentioned multi-layer polyimide film is preferably a co-extrusion-casting film forming method (also simply referred to as a multi-layer extrusion method) for a substrate polyimide dope solution and a thin layer polyimide dope solution. And a method of obtaining a multi-layer polyimide film by laminating, drying, and imidizing, or by casting a dope solution of the above-mentioned substrate polyimide on a support, and drying one side of a self-supporting film (gel film) or It can be obtained by a method of applying a thin layer polyimide dope solution on both surfaces, drying and imidizing to obtain a multilayer polyimide film.

For the purpose of limiting the gelation of the above polyamic acid, a phosphorus-based stabilizer such as triphenyl phosphite and triphenyl phosphate is added in an amount of 0.01 relative to the solid content (polymer) concentration during the polyamic acid polymerization. It can be added in the range of ˜1%. For the purpose of promoting imidization,
An imidizing agent can be added to the solution. For example,
0.05 to 10% by weight of imidazole, 2-imidazole, 1,2-dimethylimidazole, 2-phenylimidazole, benzimidazole, isoquinoline, substituted pyridine and the like with respect to polyamic acid, In particular, it can be used in a proportion of 0.1 to 2% by weight. They can complete the imide at relatively low temperatures.

For the purpose of stabilizing the adhesive strength, an organoaluminum compound, an inorganic aluminum compound or an organotin compound may be added to the thermocompression bonding polyimide raw material dope. For example, aluminum hydroxide, aluminum triacetylacetonate, etc. as aluminum metal with respect to polyamic acid is 1 ppm or more, particularly 1 to 1000 p.
It can be added in the proportion of pm.

As the polyimide for the base layer, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA) are used in addition to the above polyimide. It is prepared from para-phenylenediamine (PPD) and 4,4'-diaminodiphenyl ether (DADE). In this case, BTDA in the acid dianhydride is 20 to 90 mol%, PMD
A is 10 to 80 mol%, PPD in diamine is 30 to 90
It is preferable that mol% and DADE are 10 to 70 mol%.

As the heat-resistant polyimide as the above-mentioned substrate layer, it is preferable to use a polyimide film which cannot be confirmed to have a glass transition temperature of 300 ° C. or higher, particularly 320 ° C. or higher. In the base layer polyimide in the present invention, finally, if the ratio of each component is within the above range, random polymerization, block polymerization, or 2
It can be achieved by any method in which a polyamic acid of a kind is synthesized and both polyamic acid solutions are mixed and then mixed under reaction conditions to form a uniform solution.

Using each of the above components, approximately equimolar amounts of the diamine component and the tetracarboxylic acid dianhydride are reacted in an organic solvent to produce a solution of polyamic acid (partly if a uniform solution state is maintained. May be imidized).
Aromatic tetracarboxylic dianhydride and aromatic diamine other types and amounts that do not impair the physical properties of the base layer polyimide,
For example, 4,4'-diaminodiphenylmethane or the like may be used.

The organic solvent used for the production of the above polyamic acid is N-methyl-2-pyrrolidone, N, N, for both the polyimide for the base layer and the polyimide for the thin layer.
Examples thereof include N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, N-methylcaprolactam, and cresols. These organic solvents may be used alone or in combination of two or more.

In the production of the above-mentioned multilayer polyimide film, for example, a polyamic acid solution of heat-resistant polyimide for the above-mentioned base layer and a solution of thermocompression-bondable polyimide for a thin layer or a precursor solution thereof are coextruded to obtain a stainless mirror surface. ,
100 to 200 by casting on a support surface such as a belt surface.
It is preferable to bring it to a semi-cured state or a dried state before that at ℃. When the cast film is processed at a high temperature of over 200 ° C., in the production of the multilayer polyimide film,
It tends to cause defects such as deterioration of adhesion. The semi-cured state or a state before the above means that it is in a self-supporting state by heating and / or chemical imidization.

The co-extrusion of the solution of the polyamic acid that gives the polyimide for the base layer and the solution of the polyamic acid that gives the polyimide for the thin layer is described in, for example, Japanese Patent Application Laid-Open No. 3-1803.
No. 43 (Japanese Examined Patent Publication No. 7-102661) is supplied to a three-layer extrusion molding die by the coextrusion method,
It can be performed by casting on a support. On one or both sides of the extrudate layer that gives the substrate layer polyimide, a solution of a polyamic acid that gives a polyimide for a thin layer or a polyimide solution is laminated to form a multilayer film-like product and dried, and then a glass of a polyimide for a thin layer. Heating to a temperature not lower than the transition temperature (Tg) and at which deterioration occurs, preferably 250 to 420 ° C. (surface temperature measured by a surface thermometer) (preferably heating at this temperature for 1 to 60 minutes) Then, it can be dried and imidized to produce a multilayer extruded polyimide film having a thin layer polyimide on one or both sides of a substrate layer polyimide, preferably a thermocompression-bondable multilayer extruded polyimide film.

The thin layer polyimide preferably has a glass transition temperature of 190 to 280 ° C., particularly 200 to 275 ° C. by using the acid component and the diamine component.
And preferably achieved by drying and imidizing under the above conditions to substantially prevent gelation of a thin layer (preferably thermocompression bonding) polyimide, at a glass transition temperature of 300 ° C. or higher. It is preferable that the material does not melt at a temperature within the following range and maintains the elastic modulus (usually, the elastic modulus at 275 ° C. is about 0.001 to 0.5 times the elastic modulus at 50 ° C.).

In the above-mentioned multilayer polyimide film, the thickness of the base layer polyimide film (layer) is preferably 5 to 125 μm, and the thickness of the thin layer polyimide (Y) layer is 1 to 25 μm, particularly 1 to 15 μm. , Especially 2
12 μm is preferable. The thickness of the heat-fusible polyimide (Y) layer, which is a thin layer when laminated with the other metal foil, is equal to or larger than the surface roughness (Rz) of the other metal foil used. preferable. In particular, as a multi-layer polyimide film, it has heat-fusible polyimide layers on both sides, and the total thickness is 7 to 150 μm, particularly 7 to 50 μm, and in particular 7
˜25 μm, tensile modulus (MD, TD, 2
A material having a temperature of 5 ° C.) of about 400 to 1000 kgf / mm ² is preferable from the viewpoint of high density.

In the present invention, examples of the metal layer to be laminated on the multilayer polyimide film include metal foils of copper, aluminum, iron, gold and the like, or alloy foils of these metals, preferably metal layers (A layer). Rolled copper foil, electrolytic copper foil or SUS foil and copper foil as metal layer (B layer), S
Combination of US foils, or rolled copper foil as metal layer (A layer), electrolytic copper foil or SUS foil and metal layer (B layer)
The combination with the SUS plate as. It is preferable that the copper foil as the metal layer (A layer) has a thickness of about 3 to 18 μm, and the SUS foil has a thickness of about 10 to 35 μm. The SUS foil or SUS plate as the metal layer (B layer) preferably has a thickness of about 20 to 200 μm.

Further, as the copper foil, the surface roughness is not so large and not so small, preferably, Rz of the contact surface with the thin layer polyimide is 3 μm or less, particularly 0.5 to 3 μm, and particularly 1.5 among them. It is preferably about 3 μm. Such metal foils, such as copper foil, are VLP, LP (or HT
Known as E). When Rz is small, a metal foil surface-treated may be used.

In the present invention, preferably, the thermocompression-bonding multilayer polyimide film and the metal foil are compressed by a compression device,
Alternatively, it is a continuous laminator such as a roll laminator or a double belt press, which is 150 to 150 in-line immediately before introducing the thermocompression-bondable multilayer polyimide film or the thermocompression-bondable multilayer polyimide film and the metal foil.
By preheating using a preheater such as a hot air supply device or an infrared heater so that it can be preheated at a temperature of about 250 ° C., particularly higher than 150 ° C. and 250 ° C. or less for about 2 to 120 seconds, and by heating and pressure bonding A laminate that is a flexible metal foil laminate can be obtained. The above-mentioned double belt press is capable of performing high temperature heating and cooling under pressure, and is preferably a hydraulic type using a heat medium. The in-line is to install a preheating device between the raw material feeding device and the crimping part of the continuous laminator,
Immediately after that, the equipment is arranged so that it can be crimped.

In particular, in the above-mentioned laminate, the temperature of the thermocompression bonding zone of a roll laminate or a double belt press is preferably 20 ° C. higher than the glass transition temperature of the heat-fusible polyimide.
The temperature is higher than 400 ° C. and higher, especially 30 ° C. or higher and 400 ° C. or lower than the glass transition temperature, and thermocompression bonding is performed under pressure. The temperature is preferably 20 ° C. or more lower than the glass transition temperature of the thermocompression-bondable polyimide, particularly 30.
It can be manufactured by cooling to a temperature lower than 0 ° C or lower and laminating, and has a high adhesive strength (90 ° peel strength is 0.8 kgf / cm or more, particularly 1 kgf / cm or more).

By the method described above, particularly using a double belt, the length is about 400 mm or more and the width is particularly about 500 mm.
mm wide or more, high adhesive strength (90 ° peel strength of 0.8 kgf / cm or more, especially 1 kgf / cm or more), and good appearance with substantially no wrinkles on the metal foil surface. A laminated body can be obtained.

In the laminate obtained by the present invention, a metal layer is usually subjected to a method known per se, for example, a positive type photoresist is applied to a metal foil of the laminate and dried, and then exposed to ultraviolet rays and alkali development. For example, diameter 30
A resist pattern having holes of ˜150 μm arranged at intervals of 100 to 200 μm is prepared, and then the metal foil exposed with an etching solution containing ferric chloride is etched to form a pattern.
After forming the resin, the polyimide layer is used as a mask by using a metal foil etched into a desired pattern as a mask, and the polyimide layer is subjected to a method known per se, for example, ethanolamine or iso- or dipropanoic acid described in JP-A-10-97081. Lumine 20 to 50% by weight and potassium hydroxide (KOH) 25
To 40 wt% and 25 to 40 wt% water on a polyimide film at 50 to 80 ° C. for 5 to 20 minutes (when the polyimide film thickness is 50 μm),
Preferably, the polyimide film is chemically etched by contacting and processing using an etching apparatus equipped with an ultrasonic transmitter to form through holes in the film to form a substrate. be able to.

The layered product of the present invention preferably has a chemical etching rate of chemical etching rate and a peeling strength between a polyimide film and a copper foil or stainless steel foil.
2.0 μm / min or more, copper side peel strength of 1 kg / cm or more, stainless steel side peel strength of 0.8 kgf / cm or more,
In particular, at 1 kgf / cm or more, the electrical characteristics are equivalent to those of the conventionally known heat-meltable polyimide.

The substrate obtained by subjecting the metal layer of the laminate of the present invention, and then the multilayer polyimide layer to chemical etching, can be suitably used as a substrate for electronic parts. For example,
It can be suitably used as a suspension for a hard disk drive, or as a base substrate for FPC, TAB, and a multilayer substrate.

[0040]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In each of the following examples, the evaluation of the physical properties of the polyimide film and the peel strength of the laminate with the copper foil and stainless steel were measured according to the following methods. Chemical etching property: A test piece obtained by bonding a polyimide film and a stainless steel foil (about 20 μm) is immersed in an etching solution (composition: 36% by weight potassium hydroxide, 37% by weight monoethanolamine, 27% by weight water) at 80 ° C. The time taken for the polyimide film to completely dissolve was measured. Etching rate (μm / min) = Polyimide film thickness (μm) / Time required for complete dissolution (min)

Peel strength of the laminate: Using a hot press kept at 340 ° C., laminated with rolled copper foil (18 μm: manufactured by Japan Energy) / polyimide film (16 μm) / stainless foil (20 μm: manufactured by Nippon Steel), After preheating for 5 minutes, 60
Pressing was performed at a pressure of kgf / cm ² for 1 minute to obtain a three-layer laminate. About this laminate, at room temperature 50 mm /
The 90 degree peel strength was measured in minutes. Melting endothermic peak: DSC (DSC220C: manufactured by Seiko Denshi Kogyo KK) was used to measure from RT to 500 ° C. (20 ° C./min).

In the following description, each abbreviation means the following compound. s-BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PMDA: pyromellitic dianhydride BTDA: 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride ODPA: 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride TPE-R: 1,3-bis (4-aminophenoxy) benzene

Example 1 To synthesize a polyamic acid solution, dimethylacetamide (DMA) was placed in a reaction vessel equipped with a stirrer and a nitrogen introducing tube.
c) and TPE-R were added and dissolved. Furthermore, s-BPD
A, PMDA and BTDA were added at a molar ratio of 70:20:10 and DM was added so that the concentration of the monomer solution was 18% by weight.
Ac was added. After the addition was completed, the reaction was carried out at room temperature for 3 hours to obtain a polyamic acid solution. This solution was cast on a glass plate using a 230 μm spacer, dried at 100 ° C., and then gradually heated from 180 ° C. to 360 ° C. to remove the solvent and imidize. A polyimide film having a thickness of 19 μm was manufactured. Using this polyimide film, rolled copper foil (18 μm: manufactured by Japan Energy)
/ Polyimide film (19 μm) / Stainless foil (2
0 μm: made by Nippon Steel Co., Ltd.) and preheated for 5 minutes, then 60 kg
Pressing was performed for 1 minute at a pressure of f / cm ² to obtain a three-layer laminate. The laminate was evaluated for etching property and peel strength of copper foil and stainless foil. Etching rate: 2.24 μm / min, copper peel strength: 1 kgf / c
m or more, and the stainless steel peeling strength: 1 kgf / cm or more. As a result of DSC measurement, a melting endothermic peak was observed at 350 ° C.

Example 2 The molar ratio of s-BPDA, PMDA and BTDA was 75: 1.
A polyimide film was produced in the same manner as in Example 1 except that the ratio was 5:10. Using this polyimide film, a laminate was obtained in the same manner as in Example 1. When the etching property and the peel strength of the copper foil and the stainless steel foil were evaluated for this laminate, the etching rate was 1.71 μm.
m / min, copper peeling strength: 1.0 kgf / cm or more, stainless steel peeling strength: 1.0 kgf / cm or more. DS
When C measurement was performed, a melting endothermic peak was observed at 350 ° C.

Comparative Example 1 The molar ratio of s-BPDA, PMDA and BTDA was 60: 3.
A polyimide film was produced in the same manner as in Example 1 except that it was set to 0:10. The laminate obtained using this film was evaluated for etching property and peel strength of copper foil and stainless foil, and the etching rate was 1.7.
The peel strength was 1 μm / min, the copper peel strength was 0.3 kgf / cm, and the stainless peel strength was 0.0 kgf / cm. As a result of DSC measurement, a melting endothermic peak was observed at 380 ° C. The peel strength was significantly reduced.

Comparative Example 2 The molar ratio of s-BPDA, PMDA and BTDA was 80: 1.
A polyimide film was produced in the same manner as in Example 1 except that it was set to 0:10. The laminate obtained by using this film was evaluated for etching property and peel strength of copper foil and stainless steel foil. Etching rate: 1.2
7 μm / min, copper peeling strength: 0.8 kgf / cm, stainless steel peeling strength: 1.0 kgf / cm or more. DS
When the C measurement was performed, no melting endothermic peak could be observed.
The etching rate was significantly reduced.

Comparative Example 3 The molar ratio of s-BPDA, PMDA and BTDA was 70: 3.
A polyimide film was produced in the same manner as in Example 1 except that it was 0: 0. The laminate obtained by using this film was evaluated for etching property and peel strength of copper foil and stainless steel foil. Etching rate: 2.00
μm / min, copper peeling strength: 0.7 kgf / cm, stainless steel peeling strength: 0.0 kgf / cm. No melting endothermic peak could be observed by DSC measurement. The peel strength from stainless steel was significantly reduced.

Comparative Example 4 A polyimide film was produced in the same manner as in Example 1 except that ODPA was used as the acid anhydride. The laminate obtained by using this film was evaluated for etching property and peel strength of copper foil and stainless foil. Etching rate: 0.49 μm / min, copper peel strength: 1.0 k
gf / cm or more, stainless steel peel strength: 0.5 kgf /
It was cm. No melting endothermic peak could be observed by DSC measurement. The etching rate was significantly reduced, and the peel strength from stainless steel was reduced.

Example 3 To synthesize a dope for producing the base polyimide layer (X), dimethylacetamide (DMAc) was added to a reaction vessel equipped with a stirrer and a nitrogen introducing tube, and paraphenylenediamine (PPD) and s were added. -BPDA was added at a molar ratio of 100: 99.8 to a monomer concentration of 18% by weight. After the addition was completed, the reaction was continued for 3 hours while maintaining 50 ° C. The obtained polyamic acid solution for the base layer was a brown viscous liquid, and the solution viscosity at 25 ° C. was about 1500 poise.

Three-layer extrusion of the polyamic acid solution for the thin layer polyimide of Example 1 and the above-mentioned polyamic acid solution for the base layer were carried out using a film forming apparatus provided with a die, and the above polyamic acid solution was extruded in three layers. It was cast from a die onto a metal support and continuously dried with 140 ° C. hot air to form a solidified film. After peeling this solidified film from the support, the temperature was gradually raised from 200 ° C. to a final temperature of 400 ° C. in a heating furnace to remove the solvent and imidize, and to form a long film having a thickness of
A 6-μm (structure: 2 μm / 12 μm / 2 μm) three-layer extruded polyimide film was produced. This three-layer polyimide film has a tensile elastic modulus (MD, TD, 25 ° C.) of 77.
It was 0 to 800 kgf / mm ² . Using this three-layer extruded polyimide film, a laminate was obtained in the same manner as in Example 1. When the chemical etching property and the peel strength of the copper foil and the stainless steel foil were evaluated for this laminate,
Chemical etching rate: 2.83 μm / min, copper peeling strength: 2.0 kgf / cm or more, stainless steel peeling strength:
It was 1.1 kgf / cm. The shape after chemical etching was also good.

Example 4 The procedure of Example 3 was repeated except that the polyamic acid solution for thin layer polyimide of Example 2 was used, and the thickness was 16 μm.
A three-layer extruded polyimide film (structure: 2 μm / 12 μm / 2 μm) was produced. This three-layer polyimide film has a tensile elastic modulus (MD, TD, 25 ° C.) of 770 to 8
It was 00 kgf / mm ² . Using this three-layer extruded polyimide film, a laminate was obtained in the same manner as in Example 1. When the chemical etching property and the peel strength of the copper foil and the stainless steel foil were evaluated for this laminate, the chemical etching rate: 2.21 μm / min, the copper peel strength:
2.0 kgf / cm or more, stainless steel peel strength: 1.0
It was kgf / cm. The shape after chemical etching was also good.

[0052]

According to the present invention, the peel strength of a laminate obtained by heat-sealing a SUS foil (stainless steel foil) and a polyimide film with a heat-fusible polyimide layer is high, and the heat-fusible polyimide is By chemically etching the layer, it is possible to obtain a heat-fusible polyimide having a short etching time when forming a pattern.

Further, according to the present invention, the peel strength of the laminate obtained by heat-sealing the SUS foil (stainless steel foil) and the multilayer polyimide film via the heat-fusible polyimide layer is large, and the polyimide layer Due to the chemical etching, the etching time is short when the pattern is formed.
It is possible to obtain a multi-layer polyimide film having a good chemical etching property with a good shape.

Furthermore, according to the present invention, the peel strength of the laminate obtained by heat-sealing the SUS foil (stainless steel foil) and the polyimide film with the heat-fusible polyimide layer is high, and the polyimide layer is chemically etched. As a result, it is possible to obtain a laminate having a short etching time when forming a pattern and further having a chemical etching characteristic that the shape of the pattern is good.

Continued front page    F-term (reference) 4F100 AB01C AB01D AB04C AB04D                       AB17C AB17D AB33C AB33D                       AK49A AK49B BA02 BA03                       BA04 BA10A BA10C BA10D                       BA25C BA25D EH202 EH462                       EJ862 JA20A JB16A JK06                       JL12A YY00 YY00C YY00D                 4F205 AA40 AC05 AG03 AH36 GA07                       GB02 GB26 GE21 GF01 GF24                 4J043 PA05 PA08 PB08 PB15 QB26                       RA34 SA06 SB02 TA22 TB04                       UA122 UA132 UA141 UB121                       UB152 XA16 XA17 XA19                       ZA05 ZB03 ZB50

Claims (12)

[Claims] 1. The following formula: [In the formula, Ar ₁ is a tetracarboxylic acid dianhydride residue, 12 to 25 mol% of 100 mol% thereof is a pyromellitic dianhydride residue, and 5 to 15 mol% is 3,3 ′, 4. , 4'-
Benzophenone tetracarboxylic acid dianhydride residue, the rest is 3,3 ′, 4,4′-biphenyltetracarboxylic acid dianhydride residue, Ar ₂ is 1,3-bis (4-aminophenoxy) benzene It is an aromatic diamine residue that is an essential component. ] The heat-fusion-bonding polyimide which has an imide unit shown by these and whose melting endothermic peak can be observed by DSC measurement. 2. The melting endothermic peak measured by DSC is 34
The heat-fusible polyimide according to claim 1, which can be observed at 0 to 380 ° C. 3. A multilayer polyimide film in which the thin polyimide layer (Y) made of the heat-fusible polyimide described in claim 1 is laminated and integrated on at least one surface of the base polyimide layer (X). 4. The base polyimide layer (X) is composed of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and p-phenylenediamine 100.
-10 mol% or 4,4'-diaminodiphenyl ether
A polyimide obtained from 0 to 90 mol% of ter, or 0 to 100 mol% of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride 1
00 to 0 mol% and p-phenylenediamine 10 to 90 mol% and 4,4'-diaminodiphenyl ether 90
The multilayer polyimide film according to claim 3, which is composed of a polyimide obtained from 10 to 10 mol%. 5. The lamination integration is carried out by laminating a polyamic acid solution for a base polyimide layer and a polyamic acid solution for a thin polyimide layer by coextrusion and casting and then heating and drying to imidize. The multilayer polyimide film according to claim 3, which is formed by: 6. A thin layer polyimide on at least one side of a self-supporting film formed from a polyamic acid solution for a substrate layer wherein the laminate integration provides a substrate polyimide (X).
A thin layer of polyamic acid solution for giving (Y) is applied thinly,
The multilayer polyimide film according to claim 3, wherein the multilayer polyimide film is dried by heating and imidized. 7. A thin-layer polyimide, wherein the multilayer polyimide film according to any one of claims 3 to 6 and the metal layer are thin-layer polyimides.
A laminate formed by laminating (Y). 8. The laminate according to claim 7, wherein the laminate is formed by superposing a thin polyimide (Y) layer of a multilayer polyimide film and a metal foil, and then thermocompression bonding. 9. The laminate according to claim 7, wherein the metal foil has a thickness of 3 to 35 μm. 10. A copper foil or SU having a thickness of 3 to 35 μm
S (stainless steel) foil / multilayer polyimide layer in which a thin polyimide layer (Y) made of heat-fusible polyimide is laminated and integrated on both sides of a base polyimide layer (X) having a thickness of 7 to 150 μm and made of highly heat-resistant polyimide. / Thickness is 3-200μ
m has a three-layer structure of a copper foil, a stainless steel foil or a stainless steel plate, and the heat-meltable polyimide has a melting endothermic peak which can be observed by DSC measurement, and the multilayer polyimide layer has a tensile elastic modulus (MD) as a film. , TD, 25 ° C) is 400 ~
Chemical etching rate of 1000 kgf / mm ² and 2.0 μm / min or more, and 9 for both sides
A laminate having a 0 degree peel strength of 0.8 kgf / cm or more. 11. The metal layers on both sides have a thickness of 3 to 35 μm.
11. The SUS (stainless steel) foil and the stainless steel foil or the stainless steel plate having a thickness of 20 to 200 μm.
The laminated body according to. 12. The metal layers on both sides have a thickness of 3 to 18 μm.
11. The laminate according to claim 10, which comprises the copper foil and the stainless steel foil or the stainless steel plate having a thickness of 20 to 200 μm.