JP2007281361A - Polyimide printed circuit board and polyimide printed wiring board - Google Patents

Abstract

The present invention provides a polyimide printed circuit board having high 180 ° copper foil peel strength and high repeated folding resistance and excellent in fine wiring formation, and a polyimide printed wiring board using the printed circuit board.
A copper foil having a roughened surface with protrusions formed on at least one surface of a non-thermoplastic aromatic polyimide resin film is bonded via a pressure-sensitive polyimide resin layer obtained by imidizing polyamic acid. In the polyimide-based printed circuit board bonded at the roughened surface, D (diameter) of the protrusion is 10 to 100 nm, and L (length) / D (diameter) is 1.5 or more. A copper foil bonded polyimide printed circuit board.
[Selection figure] None

Description

  The present invention relates to a flexible polyimide printed circuit board having uniform and strong adhesion and excellent bending resistance. The polyimide-based printed board of the present invention can be used for flexible printed boards for TAB, COF, etc., multilayer flexible boards, and flex-rigid boards, and printed wiring boards made of these can be suitably used for electronic equipment.

  In recent years, electronic devices have become smaller and lighter, and in order to mount semiconductor chips and the like at a high density in a limited volume, flexible polyimide-based printed boards that can be folded thinly are often used. . As such a printed circuit board, a flexible board for electronic circuits is generally used in which copper foil and aromatic polyimide are bonded by a casting method, or copper foil and aromatic polyimide are bonded using a polyimide-based adhesive. ing. Also, in the field of flat panel displays such as liquid crystal displays and plasma displays, an IC chip for driving these display elements is mounted on the flexible substrate as described above, and an electronic circuit substrate is mounted on the back surface of the display element at a right angle or 180 degrees. Incorporating in a state bent to °. In these applications, in order to improve the bending workability, in recent years, the thickness of the polyimide insulating layer is becoming 30 μm or less.

  In these applications, fine wiring can be formed and the strength must be maintained high even when severely bent, and there is little variation in strength due to strength design, and high durability against repeated bending is required. It has been.

  Conventionally, in order to overcome these problems, attempts have been made to increase the surface roughness of the roughened surface of the copper foil and increase the peel strength from the copper foil by the anchoring effect on the polyimide base material. When the roughness is rough, there are problems such as repeated bending resistance deterioration and deterioration of fine wiring formability of the printed circuit. For example, a method using a copper foil having a surface roughness (Rz) larger than 2.5 μm can obtain a high peel strength, but the line width (LW) / inter-conductor space (S) = 100 μm / 100 μm. Adaptation to the high density design of the printed circuit board which has the following fine wiring was not enough.

  Conventionally, epoxy adhesives and epoxy base materials with good adhesiveness have been used as means for increasing the copper foil peel strength, but they become hard due to the hardening action and require bending workability. It can not be used for applications and heat resistant applications.

  In addition, by increasing the thickness of the copper foil to, for example, 18 μm or more, it is possible to increase the copper foil peel strength by utilizing the rigidity of the copper foil. Will be reduced.

  Furthermore, it is not preferable to increase the thickness of the polyimide layer as the insulating layer because it causes a decrease in bending workability and dimensional stability. In recent years, polyimide resins having a thickness of about 30 μm or less have begun to be used.

  On the other hand, it can be expected to obtain good fine wiring formability by a combination of a copper foil having a surface roughness (Rz) of 2.5 μm or less and a polyimide base material, but with them, a sufficiently satisfactory copper foil peel strength can be obtained. I couldn't.

  For example, in Patent Document 1, there is an example of joining of an electrolytic copper foil having a thickness of 12 μm and Rz = 1.15 and a polyimide having a thickness of 25 μm prepared by a cast method, but the 90 ° copper foil peel strength is 8 N / cm. The degree is low.

  In Patent Document 2, adhesion to a polyimide with a thickness of 25 μm is improved by attaching a specific trace metal to a commercially available F1-WS copper foil with a thickness of 12 μm whose surface roughness (Rz) is 2.5 μm or less. However, the 90 ° copper foil peel strength is less than 9 N / cm.

  Patent Document 3 includes an example in which a copper foil having a thickness of 12 μm or less and a surface roughness (Rz) of 3 μm or less and a polyimide film having a thickness of 25 μm are bonded to each other using a polyamide-based adhesive. Even by this method, the 90 ° copper foil peel strength is as low as 8 N / cm. Thus, various studies have been made only by improving the 90 ° copper foil peel strength by 1 N / cm.

  Recently, as an example of emphasizing severe bending workability of 180 °, Patent Document 4 discloses 180 ° copper foil peel strength using a rolled copper foil containing a specific metal. There is a description of 8 to 13.5 N / cm at 180 ° peel strength using a very thick copper foil with a thickness of 35 μm, but if a thick copper foil is used, a high numerical value for its rigidity contribution will come out. Obviously, the value is considerably smaller when implemented with a thin copper foil.

  On the other hand, the copper foil having a surface roughness (Rz) larger than 2.5 μm has a problem that the wiring formability is lowered, or the copper foil having a thickness of 35 μm needs to be etched to reduce the thickness. It has been difficult to achieve lighter and thinner printed circuit boards and wiring boards.

  As a technique similar to the present invention (see Patent Document 5), there is a technique of laminating a copper foil in which a secondary projection group having a small diameter is formed on a primary projection group having a diameter of 0.5 to 2 μm with an epoxy resin. . If the abundance ratio of the primary projections is slightly below 80%, the 90 ° copper foil peel strength is 7. Even if the abundance ratio of secondary projections of 0.5 μm or less is 80% or more (Rz = 2.1 μm). It is pointed out that it is as low as 6 N / cm (Comparative Example 12). It is not possible to improve the copper foil peel strength simply by controlling the diameter of the secondary protrusions to 0.01 to 0.5 μm, so the diameter of the primary protrusions and the abundance ratio thereof, the diameter of the secondary protrusions and the abundance ratio thereof, In addition, there is a description that this is achieved by defining the surface roughness of the copper foil. This is a high 90 ° copper foil peel strength of 11.2 N / cm (Rz = 2.2 μm) for the first time after using Rz having a roughness greater than 2 μm, even though it has high adhesion to an epoxy substrate. It is something that demonstrates.

  However, in the technique of Patent Document 5, when the diameter of the primary protrusion on the rough surface of the copper foil is smaller than 0.5 μm, there is no anchoring effect, and the abundance ratio is 14 to 19%. Since the secondary protrusion having a large diameter is placed on the primary protrusion having a diameter of 0.5 to 2 μm, the variation in shape becomes large, and there is a concern about the variation in fine wiring formability. Moreover, although the surface roughness (Rz) of the copper foil exceeds 2 μm, the line width (LW) / inter-conductor space distance (S) = 100 μm / 100 μm evaluation indicates that the wiring circuit formability is good. In recent years, acceptance criteria for customers on the formation of fine wiring with such copper foils have become stricter, and it is considered that the evaluation results of fine wiring formability do not meet current customer requirements.

  In Patent Document 5, there is no disclosure of improvement in severe 180 ° peel strength and repeated folding resistance such as helix folding of polyimide printed circuit boards and polyimide printed wiring boards which are inferior in adhesion to epoxy systems, and This is different from the technical idea of increasing the 180 ° copper foil peel strength in polyimide printed boards and wiring boards.

As described above, in recent years, while the high convenience of mobile phones has been pursued, the wiring pitch of the flexible printed circuit board has been further reduced and the wiring density has been increased. A high degree of reliability is demanded together with miniaturization of wiring, and it is important to have a 90 degree copper foil peel strength and a more severe 180 degree copper foil peel strength improvement.
JP 2002-217507 A JP 2003-251741 A Japanese Patent Laid-Open No. 2003-13666 JP 2003-41334 A Japanese Patent Laid-Open No. 10-341066

  The present invention provides a polyimide-based printed circuit board having high 180 ° copper foil peel strength and high repeated folding resistance, and excellent in fine wiring formability, and a polyimide-based printed wiring board using the printed circuit board.

(1) A polyimide in which a copper foil having a roughened surface with protrusions formed on at least one surface of a non-thermoplastic aromatic polyimide resin film is bonded to the roughened surface via a pressure-sensitive adhesive polyimide resin layer. A copper foil-bonded polyimide-based printed board, wherein the protrusion has a D (diameter) of 10 to 100 nm and an L (length) / D (diameter) of 1.5 or more.
(2) The polyimide printed circuit board according to (1) above, wherein the pressure-sensitive polyimide resin layer has a thickness of 10 μm or less.
(3) The polyimide printed circuit board according to (1) or (2), wherein the glass transition temperature of the pressure-sensitive polyimide resin is 200 to 350 ° C.
(4) A polyimide-based printed board in which a copper foil is bonded to at least one surface of a polyimide resin layer, the copper foil having a roughened surface on which protrusions are formed, and polyamic acid imide on the roughened surface. The polyimide resin layer obtained by the process is bonded on the roughened surface of the foil, the D (diameter) of the projection is 10 to 100 nm, and the L (length) / D (diameter) is 1. A copper foil-bonded polyimide-based printed circuit board characterized by being 5 or more.

(5) The polyimide printed circuit board according to any one of (1) to (4), wherein the copper foil has a surface roughness (Rz) of 2.5 μm or less and a copper foil thickness of 20 μm or less.
(6) The polyimide printed circuit board according to any one of (1) to (5), wherein the protrusion is formed on roughened particles having a particle diameter of 0.1 to 10 μm.
(7) An aromatic acid dianhydride component in which the polyamic acid contains 80 mol% or more of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, and p -The polyimide type printed circuit board in any one of said (4)-(6) obtained by superposing | polymerizing the aromatic diamine component which contains 50 mol% or more combining phenylenediamine and diamino diphenyl ether.
(8) A polyimide characterized in that a 180 ° copper foil peel strength of a circuit pattern formed using the polyimide printed circuit board according to any one of (1) to (7) is 10 N / cm or more. Printed wiring board.

  The polyimide-based printed circuit board and polyimide-based printed wiring board of the present invention are obtained by imidizing a copper foil, a pressure-sensitive polyimide resin layer, or a polyamic acid that forms fine protrusions having a specific L / D ratio on a roughened surface. By joining with the polyimide resin layer obtained in this way, a high 180 ° copper foil peel strength can be achieved, and at the same time, high repeated folding resistance can be exhibited, and high strength design reliability can be obtained. Further, the printed board of the present invention is excellent in fine wiring formability, and it is possible to produce a polyimide printed wiring board on which a fine circuit pattern is formed.

  Hereinafter, the present invention will be described in detail.

  The polyimide-based printed board of the present invention includes: 1) a copper foil having a roughened surface in which D (diameter) of the protrusion is 10 to 100 nm and L (length) / D (diameter) is 1.5 or more; 2) A pressure-sensitive adhesive polyimide resin layer formed on a non-thermoplastic aromatic polyimide resin film, or a polyimide resin layer obtained by imidizing polyamic acid on the roughened surface of the copper foil is pressure-bonded. It is the printed circuit board joined by the copper foil roughening surface to at least one surface of the polyimide resin layer obtained from the conductive polyimide resin layer or the polyamic acid. Moreover, it is preferable that the 180 degree copper foil peeling strength of the circuit pattern formed using this printed circuit board of the polyimide type printed wiring board of this invention is 10 N / cm or more.

  The protrusions of the copper foil forming the printed circuit board of the present invention have D (diameter) of 10 to 100 nm and L (length) / D (diameter) of 1.5 or more. L (length) indicates the distance from the root forming the protrusion of the copper foil to the apex of the protrusion, and D (diameter) is the average diameter therebetween. When the D (diameter) of the protrusion is less than 10 nm, the protrusion is too thin and is easily broken and is not practical. When it is larger than 100 nm, the projecting effect of the protrusion on the polyimide layer is low, and sufficient 180 ° copper foil peel strength cannot be expected.

  An important factor for increasing the 180 ° copper foil peel strength is the control of the projection L (length) / D (diameter) simultaneously with the control of the projection D (diameter) within the above range. By requiring L (length) / D (diameter) to be 1.5 or more, it is possible to obtain the anchoring effect for expressing the 180 ° copper foil peel strength. When L (height) / D (diameter) is less than 1.5, the anchoring effect may not be sufficiently exhibited. The value of L (length) / D (diameter) is preferably 2 or more. The larger the value, the higher the anchoring effect on the polyimide layer can be obtained. However, it is conceivable that this protrusion becomes easy to break when it becomes a long and thin needle shape, and there is a possibility that broken copper may be mixed as a foreign substance in the laminated board for printed circuit boards or a printed circuit board made using it. The upper limit of L / D is preferably 10 or less and more preferably 5 or less because there is a risk of lowering durability.

  Examples of the shape of the protrusion on the copper foil include, but are not limited to, a cylindrical shape, an elliptical column shape, a bell shape, a rugby ball shape, a polygonal column shape, a cone shape, and a polygonal pyramid shape. The D (diameter) in the case of not a cylindrical shape such as a high-angle columnar shape can be represented by the maximum length of the parallel section with respect to the plane and the average length of the minimum length on the copper foil of the protrusion.

  Further, in order to further increase the 180 ° copper foil peel strength, the above protrusions have a particle diameter of 0.1 to 10 μm, preferably 0.1 to 3 μm, more preferably 0.1 to 1 μm, most preferably. It is preferable to be formed on roughened particles having 0.1 to 0.5 μm.

  The protrusions are preferably formed on the roughened particles in an average range of 1 to 100, more preferably an average of 2 to 50, and still more preferably an average of about 5 to 30. An average of 6 to 20 is most preferable. When the number of protrusions is small, the copper foil peel strength of 180 degrees may not be sufficiently exhibited. When the number of protrusions is large, moisture may remain in the gaps between the protrusions and solder resistance may be reduced.

  A protrusion having a D (diameter) of 10 to 100 nm and having a L (length) / D (diameter) of a predetermined value or more is formed on the roughened particles having a relatively large diameter. As a result, the projecting effect of the protrusions on the polyimide layer is further enhanced. Even if only 90% copper foil peel strength is exhibited by bonding of copper foil having only large roughened particles and a polyimide layer, 180 ° copper foil peel strength is not sufficiently exhibited. There is a possibility of causing deterioration of formability. The particle diameter of the roughened particles is preferably 0.1 μm or more from the viewpoint of copper foil peel strength.

  On the other hand, when the roughened particles are larger than a predetermined particle diameter, there is a concern that the repeated bending durability may be lowered. In particular, in a wiring circuit having a line width (LW) of 100 μm or less, the decrease may be remarkable. Therefore, in order to obtain high repeated bending durability and high peel strength, the D (diameter) of the projection is 10 to 100 nm and L (length) / D (diameter) is 1.5 or more at the same time. It is desirable that the roughened particles have a predetermined particle size.

  The copper foil of the present invention preferably has a surface roughness (Rz) of 2.5 μm or less from the viewpoint of wiring formability. More preferably, the surface roughness (Rz) is 0.1 μm or more and 2.0 μm or less. The surface roughness (Rz) of the copper foil is a 10-point average roughness.

  The thickness of the copper foil is not particularly defined, but is preferably 20 μm or less, more preferably 1 μm or more and 15 μm or less from the viewpoint of thinning the printed circuit board.

  The polyimide resin layer which comprises the printed circuit board of this invention and a printed wiring board using the same contains the polyimide resin layer obtained by superposing | polymerizing with a press-fit polyimide resin layer and / or the casting method.

  For the purpose that the protrusion of the copper foil of the present invention is accurately cast on the polyimide resin layer, the copper foil surface having the protrusion is imidized with a pressure-sensitive adhesive polyimide resin layer or a polyamic acid which is a polyimide precursor. It is preferably a printed circuit board that is bonded to the obtained polyimide resin layer and bonded to the copper foil surface in a molten state.

  The pressure-bondable polyimide resin layer is formed on the non-thermoplastic aromatic polyimide resin film, and the copper foil surface on the opposite side of the non-thermoplastic aromatic polyimide resin film through the pressure-bondable polyimide resin layer. Joined with.

  In the case of a polyimide resin layer (cast method) obtained by imidizing polyamic acid, the copper foil surface and the polyimide resin layer are joined at the time of imidization of polyamic acid which is a polyimide precursor. It is preferable to form a non-thermoplastic polyimide resin layer after imidation of the polyamic acid.

  The layer thickness (T) of the above-mentioned pressure-sensitive adhesive polyimide resin layer is preferably 10 μm or less, more preferably 0.1 to 5 μm, and most preferably 0.2 to 3 μm. For the purpose of the present invention, it is not appropriate to excessively increase the thickness of the pressure-sensitive adhesive polyimide resin layer, and when it is made thinner, it is better to be thicker than the length (L) of the protrusion of the copper foil. preferable. If it is too thin, the pressure-sensitive adhesive polyimide resin layer may be significantly damaged by the protrusions. In addition, the thickness of the resin layer of the pressure-bonding polyimide is preferably thicker than the distance between the top and bottom of the unevenness of the copper foil surface or the surface roughness (Rz) from the viewpoint of embedding in the copper foil surface. There is no limit.

  The glass transition temperature of the pressure-sensitive polyimide resin is preferably 200 to 350 ° C, more preferably 200 to 300 ° C. Although there is no restriction | limiting in particular about the elasticity modulus of a crimpable polyimide resin, It is preferable that it is 1-5 GPa by a tensile elasticity modulus. If the glass transition temperature and the elastic modulus are in the above ranges, the embedding property to the copper foil surface at the time of pressure bonding is better, and the anchoring effect can be sufficiently exhibited.

  The polyimide resin forming the pressure-bondable polyimide resin layer is designed to flow sufficiently in the initial stage of thermocompression bonding and to exhibit sufficient adhesion and heat resistance after thermocompression bonding. In general, the polyimide resin can be applied to all known methods including reacting an acid dianhydride component with a diamine component.

  As the acid dianhydride component, carboxylic dianhydrides such as tetracarboxylic dianhydride can be used singly or in combination of two or more. Specific examples of acid dianhydrides include, for example, aromatic tetracarboxylic dianhydride, pyromellitic dianhydride, 4,4′-oxydiphthalic dianhydride, 3,3 ′, 4,4′- Biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, bis (3,4- Dicarboxyphenyl) ether dianhydride, bis (3,4-dicarboxyphenyl) sulfide dianhydride, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (3,4-dicarboxyphenyl) sulfone Anhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dica Boxyphenyl) -1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis (3,4-dicarboxyphenoxy) benzene dianhydride, 1,4-bis (3,4 -Dicarboxyphenoxy) benzene dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) biphenyl dianhydride, 2,2-bis [(3,4-dicarboxyphenoxy) phenyl] propane dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, and 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,3-dihydro-1,3-dioxo-5-iso Examples thereof include benzofurancarboxylic acid-1,4-phenylene ester dianhydride.

  In addition to the aromatic tetracarboxylic dianhydrides described above, aliphatic tetracarboxylic dianhydrides can also be used. Specific examples include, for example, butane-1,2,3,4-tetracarboxylic dianhydride, pentane-1,2,4,5-tetracarboxylic dianhydride, cyclobutane tetracarboxylic dianhydride. , Cyclopentane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, cyclohex-1-ene-2,3,5,6- Tetracarboxylic dianhydride, 3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohexane-3- (1, 2), 5,6-tetracarboxylic dianhydride, 1-methyl-3-ethylcyclohex-1-ene-3- (1,2), 5,6-tetracarboxylic dianhydride, 1-ethyl Cyclohexane-1- (1,2), 3,4 Tetracarboxylic dianhydride, 1-propylcyclohexane-1- (2,3), 3,4-tetracarboxylic dianhydride, 1,3-dipropylcyclohexane-1- (2,3), 3- ( 2,3) -tetracarboxylic dianhydride, dicyclohexyl-3,4,3 ′, 4′-tetracarboxylic dianhydride, bicyclo [2.2.1] heptane-2,3,5,6-tetra Carboxylic dianhydride, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5 , 6-tetracarboxylic dianhydride, 5- (2,5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, and the like. These aliphatic tetracarboxylic dianhydrides can be used alone or in combination of two or more.

  Moreover, as a diamine component, a well-known diamine can be used 1 type or in combination of 2 or more types. Specific examples of the aromatic diamine include paraphenylene diamine, metaphenylene diamine, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 4,4′-diaminobenzophenone, and 3,4′-diamino. Diphenyl ether, 4,4′-diaminodiphenyl sulfone, 3,3′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfoxide, 3,3′-dimethyl-4,4′-diaminobiphenyl, 2,2 ′ -Dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 1,4-bis (4-amino Phenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis ( -Aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 4,4'-bis (4-aminophenoxy) biphenyl, 4, 4′-bis (3-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] ether, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) Anthracene, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-aminophenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis [4- (4-Aminophenoxy) phenyl] propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3-amino-4-methylphenyl) propyl Pan, 1,4-bis (3-aminopropyldimethylsilyl) benzene, 3,5-diaminobenzoic acid, 3,3′-dihydroxy-4,4′-diaminobiphenyl, or aromatic rings of these aromatic diamines And those in which a part of the hydrogen atoms directly bonded to each other are substituted with a group selected from the group consisting of a methyl group, an ethyl group, and a halogen group. Among these, more preferred aromatic diamines include 1,3-bis (3-aminophenoxy) benzene and 3,4'-diaminodiphenyl ether. Any of the above aromatic diamines can be used alone or in admixture of two or more.

  In addition to the aromatic diamine, an aliphatic diamine having an acyclic structure (hereinafter simply referred to as an aliphatic diamine) or a diamine having an alicyclic structure (hereinafter simply referred to as an alicyclic diamine) can be suitably used.

  Examples of aliphatic diamines include bis (aminomethyl) ether, bis (2-aminoethyl) ether, bis (3-aminopropyl) ether, bis (2-aminomethoxy) ethyl] ether, bis [2- (2 -Aminoethoxy) ethyl] ether, bis [2- (3-aminoprotoxy) ethyl] ether, 1,2-bis (aminomethoxy) ethane, 1,2-bis (2-aminoethoxy) ethane, 1,2 -Bis [2- (aminomethoxy) ethoxy] ethane, 1,2-bis [2- (2-aminoethoxy) ethoxy] ethane, ethylene glycol bis (3-aminopropyl) ether, diethylene glycol bis (3-aminopropyl) Ether group-containing diamines such as ether and triethylene glycol bis (3-aminopropyl) ether; Range amine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane And chain diamines such as 1,10-diaminodecane, 1,11-diaminoundecane and 1,12-diaminododecane. These aliphatic diamines may be used alone or in combination of two or more.

  Specific examples of the alicyclic diamine include isophorone diamine, 4,4′-diaminodicyclohexylmethane, 1,8-diamino-p-menthane, 1,4-cyclohexanebis (methylamine), 1,3-cyclohexanebis ( Methylamine), 2,5-diaminomethyl-bicyclo [2,2,2] octane, 2,5-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2,5-diaminomethyl- 7,7-difluorobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,5-diaminomethyl-7 , 7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxabicyclo [2,2,1] heptane, 2,5 Diaminomethyl-7-thiabicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,5-diaminomethyl-7-azabicyclo [2,2, 1] heptane, 2,6-diaminomethyl-bicyclo [2,2,2] octane, 2,6-diaminomethyl-7,7-dimethylbicyclo [2,2,1] heptane, 2,6-diaminomethyl- 7,7-difluorobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6-diaminomethyl-7 , 7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxybicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-thio Cyclo [2,2,1] heptane, 2,6-diaminomethyl-7-oxobicyclo [2,2,1] heptane, 2,6-diaminomethyl-7-iminobicyclo [2,2,1] heptane, 2,5-diamino-bicyclo [2,2,1] heptane, 2,5-diamino-bicyclo [2,2,2] octane, 2,5-diamino-7,7-dimethylbicyclo [2,2,1 ] Heptane, 2,5-diamino-7,7-difluorobicyclo [2,2,1] heptane, 2,5-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,5-diamino-7,7-bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,5-diamino-7-oxabicyclo [2,2,1] heptane, 2,5-diamino -7-thiabicyclo [2,2, 1] heptane, 2,5-diamino-7-oxobicyclo [2,2,1] heptane, 2,5-diamino-7-azabicyclo [2,2,1] heptane, 2,6-diamino-bicyclo [2 , 2,1] heptane, 2,6-diamino-bicyclo [2,2,2] octane, 2,6-diamino-7,7-dimethylbicyclo [2,2,1] heptane, 2,6-diamino- 7,7-difluorobicyclo [2,2,1] heptane, 2,6-diamino-7,7,8,8-tetrafluorobicyclo [2,2,2] octane, 2,6-diamino-7,7 -Bis (hexafluoromethyl) bicyclo [2,2,1] heptane, 2,6-diamino-7-oxybicyclo [2,2,1] heptane, 2,6-diamino-7-thiobicyclo [2,2, 1] Heptane, 2,6-diamino 7-oxobicyclo [2,2,1] heptane, 2,6-diamino-7-iminobicyclo [2,2,1] heptane, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4- Diaminocyclohexane, 1,2-di (2-aminoethyl) cyclohexane, 1,3-di (2-aminoethyl) cyclohexane, 1,4-di (2-aminoethyl) cyclohexane, bis (4-aminocyclohexyl) methane 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, bicyclo [2,2,1] heptanebismethylamine, and the like. It is not limited to. These alicyclic diamines may be used alone or in combination of two or more.

  In addition, a terminal blocking agent such as a carboxylic acid anhydride derivative or an amine derivative may be added during the polymerization for the purpose of sealing an amino group or dicarboxyl group present at either terminal of both ends of the polyamic acid. Good. The terminal structure of the resulting polyimide becomes an amine or acid anhydride structure depending on the molar charge ratio of all tetracarboxylic dianhydrides and all diamines at the time of production.

  The amine terminal structure may be end-capped with a carboxylic acid anhydride. Examples of the carboxylic acid anhydride include phthalic anhydride, 4-phenylphthalic anhydride, 4-phenoxyphthalic anhydride, 4- Phenylcarbonylphthalic anhydride, 4-phenylsulfonylphthalic anhydride, maleic anhydride, 5-ethynyl-phthalic dianhydride, 5-phenylethynyl-phthalic dianhydride, 5-norbornene-2,3-di Carboxy anhydride and the like can be used.

  The acid anhydride terminal structure may be end-capped with a monoamine, and examples of the monoamine include aniline, toluidine, aminophenol, aminobiphenyl, aminobenzophenone, and naphthylamine. The above acid anhydrides and monoamines may be used alone or in admixture of two or more and end-capped.

  The pressure-sensitive adhesive polyimide resin according to the present invention is preferably solvent-soluble, but is not particularly limited. “Soluble” means at least one solvent selected from dioxolane, dioxane, tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, γ-butyrolactone and the like at room temperature. It means that 1% by weight or more dissolves in a temperature range of ˜100 ° C.

  Examples of the solvent used for the reaction of the acid dianhydride component and the diamine component include γ-butyrolactone, γ-valerolactone, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl Examples include sulfoxide, 1,3-dioxane, 1,4-dioxane, cyclopentanone, cyclohexanone, diethylene glycol dimethyl ether, and tetramethylurea. Of these, γ-butyrolactone, N, N-dimethylacetamide and N-methyl-2-pyrrolidone are preferred. These can be used alone or in admixture of two or more.

  There is no restriction | limiting in particular in the usage-amount of a solvent, According to the viscosity etc. of a polyamic acid solution, it can utilize. The concentration of the reaction raw material in this reaction is usually 2 to 50% by mass, preferably 10 to 50% by mass, and the reaction temperature is usually 60 ° C. or less, preferably 50 ° C. or less. The reaction pressure is not particularly limited, and the reaction can be carried out at normal pressure. Moreover, although reaction time changes with the kind of reaction raw material, the kind of solvent, and reaction temperature, it is 0.5 to 24 hours normally. A polyamic acid polymer is produced by such a polycondensation reaction. And a pressure-sensitive adhesive polyimide resin is obtained by imidizing this polyamic acid polymer.

  Here, for the imidization, either a thermal curing method or a chemical curing method can be used. The thermal cure method is a method in which the imidization reaction proceeds only by heating without the action of a dehydrating ring-closing agent, and the chemical cure method is represented by an acid anhydride such as acetic anhydride in a polyamic acid polymer organic solvent solution. The chemical conversion agent (dehydrating agent) to be reacted with a catalyst typified by tertiary amines such as isoquinoline, β-picoline and pyridine. A chemical cure method and a thermal cure method can be used in combination. The imidation reaction conditions can be appropriately selected depending on the type of polyamic acid polymer, single or combination of known means such as thermal curing method and / or chemical curing method, or application by easy analogy.

  Usually, a pressure-sensitive polyimide resin is often used as a varnish of a soluble polyimide of about 0.3 to 500 poise in a solution state from the viewpoint of applicability, but directly and / or indirectly in a polyamic acid polymer state. In particular, a pressure-bondable polyimide resin layer can also be obtained by coating on a substrate such as a non-thermoplastic aromatic polyimide resin film or a copper foil and heating imidization.

  The pressure-bonding polyimide resin may be other resins, for example, polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyphenylsulfide, as long as the object of the present invention is not impaired. Modified polyphenylene oxide, polyamideimide, polyetherimide, epoxy resin, and the like can usually be blended in an appropriate amount not more than 10 times by weight with respect to the soluble polyimide resin.

  The pressure-bondable polyimide resin layer of the present invention is preferably formed on one side or both sides of a non-thermoplastic aromatic polyimide film. This is because the pressure-bondable polyimide resin layer is usually provided as an adhesive layer between the non-thermoplastic aromatic polyimide resin film and the copper foil, and the printed circuit board and the polyimide-based printed wiring board are often formed with those configurations. It is.

  For example, the pressure-sensitive polyimide resin layer is bonded to the non-thermoplastic aromatic polyimide resin film before, after, or simultaneously with the bonding of the copper foil of the present invention and the pressure-sensitive polyimide resin layer. Usually, the bonding of the pressure-bondable polyimide resin layer to the non-thermoplastic aromatic polyimide resin film is performed by applying the pressure-bondable polyimide resin in a solution and drying the solvent by heating. The application state is not limited to a solution state or a fluid state.

  The coating can be carried out using various known coating methods such as a blade coater, knife coater, impregnation coater, comma coater, reverse roll coater, gravure coater and the like.

  As for the thickness of the non-thermoplastic polyimide resin film of this invention, 1-125 micrometers is preferable. More preferably, it is 1-30 micrometers, More preferably, it is 3-25 micrometers, Most preferably, it is 3-22 micrometers. For the purpose of further improving the adhesive strength with the thermocompression bonding polyimide resin layer, the surface is physically applied to the surface such as dry treatment such as plasma treatment or corona treatment, wet treatment with silane coupling agents, or sand blast or wet blast. The process which forms a general unevenness | corrugation may be given.

  On the other hand, when laminating a polyimide resin layer obtained by imidizing polyamic acid on a roughened copper foil surface, there is no restriction on the type of polyamic acid that is a polyimide resin layer or a precursor that forms the polyimide resin layer, From the viewpoint of rigidity, a compound containing a unit having an aromatic component is preferably used.

  For example, as the acid dianhydride component of the constituent material of the polyamic acid, aromatic tetracarboxylic dianhydride, for example, 3, 3 ′, 4, 4′-biphenyl tetracarboxylic dianhydride and / or pyromellitic acid 2 An anhydride is mentioned as a main component. 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 1,3-dihydro-1,3-dioxo-5-isobenzofurancarboxylic acid-1,4-phenylene ester, 2,3,3 ′ Dianhydrides such as 4,4'-biphenyltetracarboxylic acid, pyromellitic acid, benzophenone tetracarboxylic acid, oxydiphthalic acid, diphenylsulfonetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, and non-aromatic Tetracarboxylic dianhydride, cyclobutanetetracarboxylic acid, cyclohexanetetracarboxylic acid and the like may be used as long as the effects of the present invention are not impaired.

  Examples of the diamine component of the constituent material of the polyamic acid include aromatic diamines such as p-phenylenediamine and 4,4′-diaminodiphenyl ether as main components. Further, metaphenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminobenzanilide, 2,2-dimethyl-4,4-diaminobiphenyl, 1,3-bis (4-aminophenoxy) benzene, 1 , 3-bis (3-aminophenoxy) benzene, 2,2-bis (4-aminophenoxyphenyl) propane, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) Phenyl) sulfone may be used as long as the effects of the present invention are not impaired.

  In particular, as the polyamic acid which is a polyimide resin precursor, aromatic acid diacid containing at least 80 mol% of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride is combined. Those obtained by polymerizing an anhydride and an aromatic diamine component containing at least 50 mol% of p-phenylenediamine and diaminodiphenyl ether are preferred.

  A polyimide resin layer obtained by imidizing polyamic acid, and a protrusion having a protrusion D (diameter) of 10 to 100 nm and L (length) / D (diameter) of 1.5 or more on at least one surface Bonding with a copper foil having a roughened surface on which an object is formed is performed on the copper foil roughening. For imidation, a known method of polymerizing acid dianhydride and aromatic diamine in an organic polar solvent and casting and drying the obtained polyamic acid on the roughened surface of the copper foil can be used.

  Examples of organic polar solvents include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylurea, γ-butyrolactone, dimethyl sulfoxide, hexamethylphosphoramide, dimethylsulfone, and tetramethylene. Examples include sulfone, dimethyltetramethylene sulfone, diglyme, and triglyme. These organic polar solvents can be used by mixing with other organic solvents such as toluene, benzonitrile and xylene. These can be used alone or in admixture of two or more.

  In addition, as long as physical properties are not impaired, additives such as dehydrating agents, fillers such as silica and calcium hydrogen phosphate, surface modifiers such as silane coupling agents and titanate coupling agents, and curing of polyimide resins are promoted. An imidizing agent such as pyridine, imidazole or triazole may be further added.

  The composition and metal layer formation of the copper foil used in the present invention are not limited. From the viewpoint of heat discoloration resistance, corrosion resistance, chemical resistance, migration resistance, circuit formability, etc., usually Cr, Zn, In, Ni, Co, Mo, Ti, W, Fe, Sn, Al, Be, It often has a surface treatment layer made of at least one metal selected from Mg, Mn, P, Pb, Si, Ag, Zr and the like. This surface treatment is used in an amount range appropriate for each purpose. As a means for forming the surface treatment layer, there are known methods such as electroplating, chemical plating, vacuum deposition, sputtering, etc., but electroplating is frequently used from the viewpoint of mass productivity.

  In order to further enhance the bonding between the copper foil and the polyimide resin layer, it is also preferable to use a silane coupling agent. Usually, a material coated on a rust-proofing layer with chromate is applied so as not to deteriorate the quality. The silane coupling agent is not limited, but various silane coupling agents can be used alone or in combination, and vinyl such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, etc. Silane coupling agent, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxy Epoxy silane coupling agents such as silane, methacrylic silane coupling agents such as γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltri Ethoxysilane, γ Amino silane coupling agents such as aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltriethoxysilane, mercapto silane coupling agents such as γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, Examples thereof include γ-chloropropyltrimethoxysilane. The silane coupling agent treatment on the copper foil surface can be carried out within a range not impairing the present invention, and is generally performed by applying and drying an aqueous solution of 0.01 to 5% by weight on the copper foil surface.

  The chemical resistance of the printed board and polyimide printed wiring board of the present invention is good for solvents such as 2N-HCl, 2N-NaOH, isopropyl alcohol, and methyl ethyl ketone.

  The 180 ° copper foil peel strength of the circuit pattern formed using the printed board of the present invention is preferably 10 N / cm or more. Furthermore, it is more preferable that the 180 ° copper foil peel strength value is at least 1.2 times the 90 ° peel strength. The polyimide-based printed circuit board obtained in the present invention has good wiring formation and good results in repeated folding resistance.

  From the viewpoint of flexibility, the elastic modulus of the non-thermoplastic aromatic polyimide resin film used in the present invention is preferably 7 GPa or less as a tensile elastic modulus at room temperature, more preferably 6 GPa or less. There is no limitation.

  In order to improve dimensional stability, the linear expansion coefficient of the non-thermoplastic polyimide resin film is preferably 10 to 30 ppm / ° C, and more preferably 10 to 20 ppm / ° C. More specifically, the linear expansion coefficient of the polyimide film made of the entire polyimide resin layer after removing the copper foil by etching is more preferably 10 to 30 ppm / ° C.

  Silicon compounds such as calcium hydrogen phosphate and silica may be added to the non-thermoplastic polyimide resin film, and the amount of the non-thermoplastic polyimide resin film is not more than 1% by using these alone or in combination of two or more, usually about 1000 to 5000 ppm. May be added in the range of.

  For the wiring pattern forming method of the polyimide-based printed wiring board of the present invention, a known method such as subtractive can be used. The wiring pattern is formed in an arbitrary shape, and the line width (LW) / inter-conductor space (S) is usually 1-1000 μm / 1-1000 μm, but is not particularly limited. From the viewpoint of folding reliability associated with recent high-density wiring, a polyimide-based printed wiring board having a wiring pattern of LW / S = 1 to 200 μm / 1 to 200 μm is preferable, and LW / S = 10 to 150 μm / 10 A polyimide-based printed wiring board having a wiring pattern of 150 μm is more preferable.

  The printed board of the present invention can be produced by the following method, but is not limited thereto. For example, on a film or copper foil made of a non-thermoplastic aromatic polyimide resin described in the present specification, a polyimide resin adhesive solution is applied to a uniform thickness, dried to remove the solvent, and then heated. The non-thermoplastic aromatic polyimide resin film and the copper foil may be laminated by applying pressure.

For example, a pressure-bondable polyimide resin layer is formed on one or both surfaces of a non-thermoplastic aromatic polyimide resin, and a copper foil is directly laminated thereon, and the laminate is supplied between a pair of heat rolls. ₂ under an inert gas atmosphere such as _{2 at} a temperature at which the thermocompression bonding polyimide resin sufficiently flows (in the range of about 60 to 400 ° C.) and continuously at a linear pressure of 1 to 500 N / mm between hot rolls. It is carried out by crimping. This method is preferably performed in an inert gas atmosphere such as nitrogen gas in order to prevent deterioration of the copper foil.

  Moreover, as another preferable manufacturing method of the copper foil laminated polyimide resin film, a known double belt method and the like can be mentioned. In this method, a laminate in which a copper foil is directly superimposed on one or both sides of a non-thermoplastic aromatic polyimide resin film via a pressure-sensitive adhesive polyimide resin is sandwiched between a pair of heated rotating heat-resistant metal belts. This is a method that is performed by continuously thermocompression bonding at a temperature at which the pressure-bonding polyimide resin starts to sufficiently flow at a surface pressure between the belts of 0.1 to 20 MPa. After the continuous pressure bonding, a post-heating treatment can be performed using a thermosetting furnace or the like for the purpose of further strengthening the adhesion or improving the solder resistance.

  In addition, as a known casting method, acid dianhydride and diamine, which are raw materials for polyimide resin, are heated in a solution state, the reaction proceeds to polyamic acid, which is a polyimide resin precursor, and the polyamic acid is used in the presence of a solvent. In some cases, the film is developed on a copper foil and the polyimide resin and the copper foil are directly joined. These heating are normally implemented in the range of about 60-400 degreeC. The processing method is often a roll-to-roll method in which raw materials are handled in a roll shape, but is not particularly limited.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
(1) Weight average molecular weight The weight average molecular weight (Mw) was measured by the gel permeation chromatograph method (polystyrene conversion) shown below.
Eluent: 0.03 mol of lithium bromide and 6.2 g of phosphoric acid (85%) were dissolved in 1 liter of dimethylformamide (DMF) to prepare an eluent.
Measurement conditions: Column: TSK gel SuperHM-M × 2 ligation. Flow rate: 0.5 mL / min, column temperature: 40 ° C., injection volume: 10 μL (sample concentration 0.2% DMF solution)
(2) Glass transition temperature (Tg)
A film of a pressure-sensitive adhesive polyimide resin was prepared by spin coating, and this was used as a test piece. After drying the test piece at 105 ° C. with a hot air dryer, using a Shimadzu Corporation thermal analyzer (TMA-50), a tensile mode, a 5 g load, a sample length of 15 mm, a heating rate of 10 ° C./min, Measurement was performed under an N2 atmosphere, and Tg was calculated from the intersection of tangents.
(3) Copper foil peel strength A polyimide resin printed circuit board with copper foil was cut into a length of 150 mm and a width of 10 mm, and the width of 1 to 3 mm at the center of the width of 10 mm was masked with a tape. The copper foil layer was etched and washed with water. Then, after removing the mask tape and drying the obtained flexible wiring board with a hot air dryer at 105 ° C., a copper foil having a width of 1 to 3 mm was peeled from the polyimide resin layer, and the stress was measured. The peeling rate was 50 mm / min, the peeling angle was 90 ° and 180 °, and 90 ° copper foil peel strength and 180 ° copper foil peel strength were determined.
(4) Repeated bending resistance Based on JIS-C6471-1994, printed wiring boards with LW / S = 1000 μm / 1000 μm and LW / S = 100 μm / 100 μm were prepared, and the number of bendings was determined.
(5) Resistance to boiling solder Cut out a copper-clad polyimide resin printed circuit board measuring 3cm in length x 6cm in width, masking 2.5cm x 2.5cm in the center with tape, and using ferric chloride aqueous solution (made by Tsurumi Soda) The copper foil layer was etched and washed with water. Then, the mask tape is removed, and the obtained sample is immersed in boiling water for 2 hours, then immersed in water at room temperature, taken out, wiped off water adhering to the surface, and immediately left at 280 ° C. for 1 minute. Evaluation was performed based on changes in appearance.
(6) Tensile modulus A film of a pressure-sensitive adhesive polyimide resin was prepared by spin coating. This was cut out to 180 mm and 15 mm in width, and measured as a test piece at a tensile speed of 50 mm / min.
(7) Surface roughness (Rz)
The surface roughness was measured in accordance with a commonly used 10-point average roughness (Rz) measurement method (JIS-B0601). The unit is μm.
(8) L (length) / D (diameter) of protrusion
The target sample was embedded with an epoxy resin, a section (70 to 100 nm) was made with an ultramicrotome perpendicular to the roughened surface of the copper foil, and observed with a transmission electron microscope at an acceleration voltage of 200 KV (manufactured by Hitachi) : HF-2000) was carried out by the following measuring method for projections observed at a magnification of 300 to 1,000,000 times. FIG. 1 is an example of an enlarged photograph of the protrusions observed in this way, and columnar protrusions having D (diameter) 32 nm and L (length) 180 nm in the center of the photograph can be observed.

  Measurement of L (length) value: The length from the top of the protrusion to the root of the protrusion was taken as L, and the measurement was made in units of 1 nm. In addition, the location of the double diameter of the position of 10 nm from the vertex of the protrusion to the root (the position of 5 nm from the vertex to the root when L is shorter than 10 nm) was defined as the root.

Measurement of D (diameter) value: The diameter of the protrusion at the apex of the protrusion and the diameter of the protrusion at the root midpoint was defined as D, and measurement was performed in units of 1 nm. The L / D value was calculated by rounding off the third digit of the decimal point.
(9) Particle diameter of roughened particles The particle diameter of the roughened particles was measured at an acceleration voltage of 3 kV and a scanning electron microscope observation (Hitachi: S-4700) at a magnification of 10,000 to 50,000 times. The particle diameter was the average of the longest diameter and the shortest diameter.
(10) Wiring formability A flexible printed wiring board having a circuit pattern of line width (LW) / space between conductors (S) = 100 μm / 100 μm is prepared based on the description of JIS-C6471-1995, and a copper circuit The linearity of the copper circuit and the sharpness of the bottom corner of the copper circuit were observed.

[Synthesis Reference Example]
A pressure-sensitive polyimide resin composition component that can be controlled to a glass transition temperature of 200 to 350 ° C. was selected depending on the configuration. 3,4,3 ′, 4′-biphenyltetracarboxylic dianhydride, 1,3-bis- (3-aminophenoxy) benzene, bicyclo (2,2,2) oct-7-ene-2,3 5,6-tetracarboxylic dianhydride and 3,5 diaminobenzoic acid were reacted by a known method to obtain an N-methylpyrrolidone solution of the pressure-sensitive adhesive polyimide resin A. The glass transition temperature of the pressure-sensitive adhesive polyimide resin A was 260 ° C., the tensile modulus was 3.3 GPa, and the weight average molecular weight was 150,000.

[Copper foil]
As the copper foil used in the present invention, 10 to 20 columnar protrusions are formed on the roughened surface of the copper foil on the roughened particles having a particle diameter of 0.4 μm per roughened particle. Electrolytic foil treated with a coupling agent, copper foil A to copper foil H were used. A copper foil having a thickness of 12 μm or 9 μm was used.

  Copper foil A has columnar protrusions having an average D (diameter) of 25 nm, L / D of 3.00, surface roughness (Rz = 1.7 μm), and thickness (T) of 12 μm.

  In the copper foil B, the columnar protrusion D has an average of 45 nm, L / D = 2.84, Rz = 1.8 μm, and T = 12 μm.

  In the copper foil C, the columnar protrusion D has an average D of 38 nm, L / D = 2.05, Rz = 1.7 μm, and T = 12 μm.

  In the copper foil D, the columnar protrusion D has an average of 34 nm, L / D = 2.03, Rz = 1.7 μm, and T = 12 μm.

  In the copper foil E, D of the columnar protrusions has an average of 65 nm, L / D = 1.66, Rz = 1.8 μm, and T = 12 μm.

  In the copper foil F, the columnar protrusion D has an average of 25 nm, L / D = 3.00, Rz = 1.6 μm, and T = 9 μm.

  In the copper foil G, D of the columnar protrusions has an average of 33 nm, L / D = 2.09, Rz = 1.6 μm, and T = 9 μm.

  The copper foil H has an average D of columnar protrusions of 70 nm, L / D = 1.59, Rz = 1.7 μm, and T = 9 μm.

  In addition, the copper foil I used in the present invention has 10 to 20 columnar protrusions per roughened particle formed on the roughened particle having a particle diameter of about 2.0 μm, and is treated with a silane coupling agent. An electrolytic copper foil having a thickness of 12 μm was used. D of the columnar protrusions has an average of 20 nm, L / D = 1.70, Rz = 3.1, and T = 12 μm.

  In FIGS. 2-3, the SEM photograph of the copper foil B rough surface used for this invention was shown. It has been observed that rough particles having an average diameter of about 0.4 μm are uniformly arranged in a columnar shape, and about 10 to 20 columnar protrusions are formed on the average.

[Example 1]
The polyimide resin film “Kapton 80EN” (manufactured by Toray DuPont Co., Ltd.) with a thickness of 20 μm was coated on both sides with a lip coater so that the thickness after drying was 2.5 μm, and after drying, A copper foil A having a thickness of 12 μm was pasted on both sides by thermocompression bonding at a temperature of 320 ° C. to produce a printed circuit board.

  The 180 ° copper foil peel strength and 90 ° copper foil peel strength of this printed board were measured. Further, repeated folding resistance (line width (LW) / inter-conductor space (S) = 1000 μm / 1000 μm) was measured.

  In accordance with the description of JIS-C6471-1995, a flexible printed wiring board having a circuit pattern of line width (LW) / inter-conductor space (S) = 100 μm / 100 μm was prepared. At that time, the etching property was good, and after etching, no remaining copper was observed on the wiring board at locations other than the copper circuit. The wiring formability was also good. The repeated folding resistance was evaluated. The results are shown in Table 1.

[Example 2]
Instead of the copper foil A used in Example 1, copper foil B was used. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
Instead of the copper foil A used in Example 1, a copper foil C was used. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
Instead of the copper foil A used in Example 1, a copper foil D was used. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
Instead of the copper foil A used in Example 1, a copper foil E was used. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 6]
Instead of the copper foil A used in Example 1, the copper foil I was used. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
Instead of the copper foil A used in Example 1, there were no protrusions on the roughened particles having a particle diameter of 0.4 μm on the rough surface of the copper foil, which had been treated with a silane coupling agent. ) Was a copper foil 1 which was an electrolytic foil of 12 μm. The copper foil 1 has a surface roughness (Rz = 1.7 μm). Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 2]
Instead of the copper foil A used in Example 1, 10 to 20 columnar protrusions are formed on each roughened particle on the roughened particle having a copper foil rough surface diameter of 0.4 μm. The copper foil 2 that was treated with a silane coupling agent and was 12 μm thick electrolytic foil was used. The copper foil 2 has an average D (diameter) of the columnar protrusions of 5 nm, L / D = 3.00, and Rz = 1.7 μm. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 3]
Instead of the copper foil A used in Example 1, 10 to 20 columnar protrusions are formed on each roughened particle on the roughened particle having a copper foil rough surface diameter of 0.4 μm. The copper foil 3 that was treated with a silane coupling agent and was 12 μm thick electrolytic foil was used. The copper foil 3 has a columnar protrusion D (diameter) average of 15 nm, L / D = 1.33, and Rz = 1.7 μm. Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 4]
Instead of the copper foil A used in Example 1, “F1-WS” (manufactured by Furukawa Electric Co., Ltd.) having no protrusions on the roughened particles having an average particle diameter of 1.0 μm on the rough surface of the copper foil The electrolytic foil treated with a silane coupling agent, the thickness was 12 μm, and the M-plane roughness Rz = 1.9 μm) was used in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 5]
Instead of the copper foil A used in Example 1, “T8G-SV” (Fukuda Metal Foil Powder Co., Ltd.) has no protrusions on the roughened particles having an average particle diameter of about 1.3 μm on the rough surface of the copper foil. ), And a silane coupling agent-treated electrolytic foil, a thickness of 12 μm, and an M surface roughness Rz = 1.8 μm) were used in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 6]
Instead of the copper foil A used in Example 1, there were no protrusions on the roughened particles having an average particle diameter of the copper foil rough surface of about 2.0 μm, and the silane coupling agent was treated. Copper foil 4, which is an electrolytic foil having a T) of 12 μm, was used. The copper foil 4 has a surface roughness (Rz = 3.0 μm). Otherwise, the test was performed in the same manner as in Example 1. The results are shown in Table 1.

[Example 7]
A 1000 ml glass separable three-necked flask equipped with a stainless steel vertical stirrer was charged with 23.7 g of p-phenylenediamine (PPD) and 11 g of 4,4′-diaminodiphenyl ether (ODA) in a nitrogen gas atmosphere. The solution was dissolved in 694 ml of N, N-dimethylacetamide (DMAc) at 50 to 80 ° C. and kept at 80 ° C. so that the solid content concentration was 15 wt%. Thereafter, 80.8 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) was gradually added to the flask and stirred for 4 hours while maintaining at 80 to 100 ° C. The solid content concentration of the polyamic acid resin solution after completion of the reaction was 15 wt%, and the E-type viscosity was 65 poise.

  This polyamic acid varnish was applied on the roughened surface of copper foil A (thickness 12 μm, electrolytic foil) kept at 80 ° C. and allowed to stand for 30 minutes, then dried at 100 ° C. for 30 minutes in an air circulation drying oven, , Heat treatment (imidization) in an air circulation drying oven at 150 ° C. for 30 minutes, 200 ° C. for 60 minutes, and 400 ° C. for 60 minutes (heating rate 5 ° C./min) A printed circuit board having a 25 μm polyimide resin insulating layer was obtained. The 180 ° copper foil peel strength and 90 ° copper foil peel strength of the obtained printed circuit board were measured. The results are shown in Table 2. A flexible printed wiring board having a circuit pattern of line width (LW) / inter-conductor space (S) = 100 μm / 100 μm was prepared based on this printed circuit board in accordance with JIS-C6471-1995. At that time, the etching property was good and the wiring formability was also good. The results are shown in Table 2.

[Example 8]
It carried out similarly to Example 7 except having used the copper foil C instead of the copper foil A used in Example 7. FIG. The results are shown in Table 2.

[Example 9]
It carried out similarly to Example 7 except having used the copper foil E instead of the copper foil A used in Example 7. FIG. The results are shown in Table 2.

[Comparative Example 7]
It carried out similarly to Example 7 except having used the copper foil 3 instead of the copper foil A used in Example 7. FIG. The results are shown in Table 2.

[Comparative Example 8]
Instead of the copper foil A used in Example 7, “F2-WS” (manufactured by Furukawa Electric Co., Ltd., silane coupling, having roughened particles having an average particle diameter of about 1.2 μm on the rough surface of the copper foil) This was performed in the same manner as in Example 7 except that the agent-treated electrolytic foil, thickness 12 μm, M surface roughness Rz = 2.1 μm) was used. The results are shown in Table 2.

[Example 10]
The polyimide resin film “Kapton 80EN” (manufactured by Toray DuPont Co., Ltd.) with a thickness of 20 μm was coated on both sides with a lip coater so that the thickness after drying was 2.5 μm, and after drying, A 9 μm-thick copper foil F was bonded to both surfaces by thermocompression bonding at a temperature of 320 ° C. to produce a printed circuit board.

  The 180 ° copper foil peel strength and 90 ° copper foil peel strength of this printed board were measured. A flexible printed wiring board having a circuit pattern of line width (LW) / inter-conductor space (S) = 100 μm / 100 μm was prepared from this printed board. At that time, the etching property was good, and after etching, no remaining copper was observed on the wiring board at locations other than the copper circuit. The wiring formability was also good. The results are shown in Table 3.

[Example 11]
It carried out similarly to Example 10 except having used the copper foil G instead of the copper foil F used in Example 10. FIG. The results are shown in Table 3.

[Example 12]
It carried out similarly to Example 10 except having used copper foil G instead of the copper foil F used in Example 10. FIG. The results are shown in Table 3.

[Comparative Example 9]
Instead of the copper foil F used in Example 10, there were no projections on the roughened particles having a particle diameter of 0.4 μm on the rough surface of the copper foil, which had been treated with a silane coupling agent, and the thickness (T ) Was used as the copper foil 5 which is an electrolytic foil of 9 μm. The copper foil 5 has a surface roughness (Rz = 1.6 μm). Otherwise, the test was performed in the same manner as in Example 10. The results are shown in Table 3.

[Comparative Example 10]
Instead of the copper foil F used in Example 10, 10 to 20 columnar protrusions are formed on each roughened particle on the roughened particle having a copper foil rough surface particle size of 0.4 μm. A copper foil 6 that was treated with a silane coupling agent and was an electrolytic foil having a thickness of 9 μm was used. The copper foil 6 has columnar protrusions with an average D (diameter) of 15 nm, L / D = 1.33, and Rz = 1.6 μm. Otherwise, the test was performed in the same manner as in Example 10. The results are shown in Table 3.

[Comparative Example 11]
Instead of the copper foil F used in Example 10, “F1-WS” (Furukawa Electric Co., Ltd.) having no protrusions on the roughened particles having an average particle diameter of about 1.0 μm on the rough surface of the copper foil. This was carried out in the same manner as in Example 10, except that an electrolytic foil treated with a silane coupling agent, a thickness of 9 μm, and an M surface roughness Rz = 1.8 μm was used. The results are shown in Table 3.

[Comparative Example 12]
Instead of the copper foil F used in Example 10, “T8G-SV” (Fukuda Metal Foil Powder Co., Ltd.) having no protrusions on the roughened particles having an average particle diameter of about 1.3 μm on the rough surface of the copper foil. ), And an electrolytic foil treated with a silane coupling agent, a thickness of 9 μm, and an M surface roughness Rz = 1.6 μm) were used in the same manner as in Example 10. The results are shown in Table 3.

  The present invention relates to a flexible polyimide-based printed circuit board that is used in the field of flat panel displays, such as liquid crystal displays and plasma displays, and is used in which a wiring board is incorporated in a state of being bent at a right angle or 180 °, and requires high bending resistance. Yes, it can be used for flexible printed boards such as TAB and COF, multilayer flexible boards, and flex-rigid boards, and printed wiring boards made of these can be suitably used for electronic devices.

TEM photograph of protrusions of copper foil (example of observation of protrusions of about 180 nm in length). Copper foil B rough surface SEM photograph (10K magnification). Copper foil B rough surface SEM photograph (example in which about 10 to 15 protrusions were observed on roughened particles of about 0.4 μm, 50K times).

Claims (8)

  A polyimide-based printed board in which a copper foil having a roughened surface with protrusions formed on at least one surface of a non-thermoplastic aromatic polyimide resin film is bonded to the roughened surface via a pressure-sensitive adhesive polyimide resin layer. A copper foil-bonded polyimide-based printed circuit board, wherein D (diameter) of the protrusion is 10 to 100 nm and L (length) / D (diameter) is 1.5 or more.   The polyimide printed circuit board according to claim 1, wherein the pressure-sensitive polyimide resin layer has a thickness of 10 μm or less.   The polyimide printed circuit board according to claim 1 or 2, wherein the pressure-sensitive polyimide resin has a glass transition temperature of 200 to 350 ° C.   A polyimide-based printed circuit board in which a copper foil is bonded to at least one surface of a polyimide resin layer, and obtained by imidizing polyamic acid on a copper foil having a roughened surface on which protrusions are formed, and the roughened surface. The polyimide resin layer is bonded to the roughened surface of the foil, and the D (diameter) of the protrusion is 10 to 100 nm, and the L (length) / D (diameter) is 1.5 or more. Copper foil bonded polyimide printed circuit board characterized by   The polyimide type printed circuit board according to any one of claims 1 to 4, wherein the copper foil has a surface roughness (Rz) of 2.5 µm or less and a copper foil thickness of 20 µm or less.   The polyimide printed circuit board according to any one of claims 1 to 5, wherein the protrusion is formed on roughened particles having a particle diameter of 0.1 to 10 µm.   An aromatic acid dianhydride component in which the polyamic acid contains at least 80 mol% of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, and p-phenylenediamine The polyimide printed board according to any one of claims 4 to 6, which is obtained by polymerizing an aromatic diamine component containing 50 mol% or more of diaminodiphenyl ether.   A polyimide-based printed wiring board characterized in that a 180 ° copper foil peel strength of a circuit pattern formed using the polyimide-based printed board according to any one of claims 1 to 7 is 10 N / cm or more. .