JP2003264350A - Board for printed circuit and printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To industrially provide a circuit board material of plating type wherein an initial adhesive force to plated copper formed on a heat-resistant film is high and the deterioration of adhesive force is extremely small after a high temperature thermal load is applied and after tin plating is performed. <P>SOLUTION: In this board for a printed circuit, a heat-resistant resin layer and a conductive metal layer are laminated in order at least on the single side of a heat-resistant insulating film. The heat-resistant resin layer is composed of resin having at least one among a sulfone base, sulfoxide base and sulfide base, and the conductive metal layer is a plated layer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a high-performance electronic device,
In particular, the present invention relates to a printed circuit board having an extremely high adhesive force, which is indispensable for reduction in size and weight. For more details,
FPC (Flexyble Print Cur) in semiconductor packages
cuit), CSP (Chip Size Package), BGA (Ball Grid)
The present invention relates to a three-layer type plated printed circuit board used for Array, COF (Chip On Film) and the like.

[0002]

2. Description of the Related Art Conventionally, as a substrate for a flexible printed circuit, a "three-layer laminate" product, which is generally a polyimide resin film and copper foil bonded with an adhesive, is used in various electric devices such as cameras, printers, and personal computers. Widely used in general. As the adhesive used for the three-layer type printed circuit board, an epoxy resin type, an acrylic resin type or the like is used alone or in combination. Since these resins contain impurity ions, there is a problem that the insulation reliability is lowered.

Regarding the heat resistance, the heat resistance of the adhesive is extremely inferior to that of the polyimide, so that the excellent characteristics of the polyimide resin film are not fully utilized.

Further, when the thickness of the copper foil to be laminated is small, it is difficult to handle, and therefore, the thickness of 18 μm or more is generally used. For this reason, the copper is too thick to perform patterning with a pitch of 80 μm (wiring width 40 μm, gap 40 μm) or less, and the etching rate is significantly reduced. The circuit width on the copper foil surface side and the circuit width on the adhesive surface side are significantly different, or There is a drawback that the entire etching becomes extremely thin and fine pitch wiring cannot be obtained. Due to such a problem, the copper foil is adhered with an adhesive to "3.
"Layer-type laminate" products have limitations in high-density mounting wiring,
It is extremely inconvenient for high-performance electronic devices that are small and lightweight.

The "two-layer cast" product, in which a copper foil is coated with a resin to form a heat-resistant insulating layer without using an adhesive, can obtain good characteristics in terms of heat resistance and insulation reliability. However, this is also difficult to handle when the thickness of the copper foil becomes thin, so that a copper foil having a thickness of 18 μm or more is used. Therefore, there is a drawback that fine pitch wiring cannot be obtained as in the case of the "three-layer laminate" product.

As a means for obtaining fine pitch wiring, a so-called adhesive-free two-layer type printed circuit in which a conductive metal layer is formed on a polyimide film by a method such as vacuum deposition, sputtering, ion plating and copper plating. Substrates have been proposed.

The "two-layer plating type" currently on the market is
Adhesion between copper layer and polyimide (90 degree peel strength) is 6N
/ Cm, and with a wiring pattern width of 100 μm or more, there is little pattern loss due to the wiring pattern forming process such as etching and resist peeling. However, there is a problem that the adhesion force after the heat load test at 150 ° C. for 10 days after forming the wiring pattern is significantly reduced to about 2 N / cm or less.

Various proposals have heretofore been made to improve the characteristics of a two-layer printed circuit board by a plating method. For example, Japanese Patent Application Laid-Open No. 4-329690 proposes a flexible electric circuit carrier composed of a chromium-based ceramic vapor deposition layer / copper or a copper alloy vapor deposition layer / copper plating layer on a film. However, after a heat load test at a higher temperature, for example, 150 ° C. for 10 days, the adhesive strength is significantly reduced. Further, there is a problem that the adhesive force after wiring processing and electroless tin plating is significantly reduced.

Japanese Unexamined Patent Publication (Kokai) No. 6-29634 proposes a structure in which a base metal thin film / copper thin film is formed on the surface of a polyimide film and a thin film having a low oxygen permeability is formed on the surface of the back surface. However, the above 150 ℃
Although the durability was improved in the heat load test, there was a problem that the adhesiveness was significantly lowered when the heat load test was performed after the wiring was formed and the electroless tin plating was performed.

[0010]

As described above, in the conventional "two-layer type plating" product, the initial adhesive strength between the plated copper layer and the polyimide interface is insufficient, and the heat after the wiring formation and electroless tin plating is performed. Significant decrease in adhesive strength after the load test,
The improvement is still desired.

The object of the present invention is to have a high adhesive force and a high adhesive force after a heat load, and further, the adhesive force between a conductive metal layer and a heat-resistant resin film made of polyimide or the like is exposed at high temperature for a long time. Even if it does not peel, it is to provide a three-layer type plating type flexible printed circuit board having excellent durability.

[0012]

That is, the present invention provides a printed circuit board in which a heat resistant resin layer and a conductive metal layer are sequentially laminated on at least one surface of a heat resistant insulating film,
A printed circuit board, wherein the heat-resistant resin layer is composed of a resin having at least one of a sulfone group, a sulfoxide group, and a sulfide group, and the conductive metal layer is a plating layer. It is a printed circuit board using a board.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The printed circuit board of the present invention comprises a heat-resistant insulating film having a heat-resistant resin layer and a conductive metal layer on at least one side, and three layers are laminated in this order. This is a printed circuit board. Therefore, other layers other than the above three layers may be inserted between the heat resistant insulating film and the heat resistant resin layer or between the heat resistant resin layer and the conductive metal layer as long as the effects of the invention are not impaired. , It may be either one layer or multiple layers. Further, at least one of the heat resistant insulating film, the heat resistant resin layer and the conductive metal layer may be composed of a plurality of layers.

The printed circuit is an electric circuit in which a metal layer is formed by etching using an optical method or the like, and is 15 to 150 μm, more preferably 20 to 1 μm.
The circuit has a pitch of 00 μm.

The heat-resistant resin layer of the present invention uses a resin having at least one of a sulfone group, a sulfoxide group, and a sulfide group in the polymer chain constituting the resin layer, so that the conductivity which has not been obtained by the prior art is obtained. The adhesiveness with the metal layer can be improved.

As the resin used for the heat resistant resin layer, epoxy resin, phenol resin, acrylonitrile resin, butadiene resin, urethane resin, polyester adhesive, polyamide resin, polyetherimide resin, polyamideimide Resins made of heat-resistant resins such as resin and polyimide resin can be used alone or in combination. Among the above resins, a polyimide resin is preferably used in terms of heat resistance, insulation reliability, and adhesiveness.

The polyimide resin in the present invention is a polymer in which an imide ring or other cyclic structure is formed by heating a polyamic acid or its ester compound as a precursor thereof or heating the same with an appropriate catalyst. Polyamic acid or its ester compound is obtained by selectively combining a tetracarboxylic acid component and a diamine component.

Examples of the tetracarboxylic acid component include tetracarboxylic acid dianhydrides such as alicyclic tetracarboxylic acid dianhydrides having cyclic hydrocarbons, aromatic tetracarboxylic acids containing an aromatic ring or an aromatic heterocycle. An acid dianhydride is mentioned.

In the present invention, the use of a tetracarboxylic dianhydride having at least one sulfone group, sulfoxide group or sulfide group in the molecule improves the adhesiveness to the conductive metal layer. As a specific example of the above-mentioned tetracarboxylic acid dianhydride, 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic acid dianhydride, 2,2 ′, 3,3′-diphenylsulfone tetracarboxylic acid dianhydride, 3,3 ',
4,4'-diphenyl sulfoxide tetracarboxylic dianhydride, 2,2 ', 3,3'-diphenyl sulfoxide tetracarboxylic dianhydride, 3,3', 4,4'-diphenyl sulfide tetracarboxylic dianhydride Things 2,2 ', 3,
3'-diphenyl sulfide tetracarboxylic dianhydride, etc. are mentioned. These tetracarboxylic dianhydrides can be used alone or in combination.

Further, other tetracarboxylic acid dianhydride can be used to the extent that the adhesiveness to the conductive metal layer is not impaired. As a specific example, 2,3,5-tricarboxycyclopentyl acetic acid dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride One, one, two, three, five-
Cyclopentanetetracarboxylic dianhydride, 1,2,4,
5-bicyclohexene tetracarboxylic dianhydride, 1,
2,4,5-cyclohexanetetracarboxylic dianhydride,
1,3,3a, 4,5,9b-hexahydro-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-C] furan-1,3-dione, 3,3 ' , 4,
4'-benzophenone tetracarboxylic dianhydride, 2,
2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride , 2,3,3 ', 4'-biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, 3,3',
4,4′-biphenyltrifluoropropanetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1, 4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,3 ", 4,4" -paraterphenyltetracarboxylic dianhydride, 3,3 ", 4,4" -metaterphenyl tetracarboxylic dianhydride, 2,3
6,7-anthracene tetracarboxylic dianhydride, 1,
2,7,8-phenanthrenetetracarboxylic dianhydride, 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride and the like can be mentioned.

As the above-mentioned diamine component, by including a siloxane-based diamine in the diamine component, the adhesiveness with the conductive metal layer is further improved. The amount of the siloxane-based diamine in the diamine component is 30 mol% or more, preferably 30 to 95 mol%, more preferably 40 to 90 mol%.
Is.

Examples of the siloxane-based diamine include those represented by the following general formula (1).

[0023]

[Chemical 2]

However, in the formula, n represents an integer of 1 or more. R ¹ and R ^{2, which} may be the same or different, each represents a lower alkylene group or a phenylene group,
^{3 to} R ⁶ may be the same or different and each represents at least one of a lower alkyl group, a phenyl group and a phenoxy group.

Specific examples of the siloxane-based diamine represented by the general formula (1) include 1,1,3,3-tetramethyl-1,3-bis (4-aminophenyl) disiloxane,
1,1,3,3-tetraphenoxy-1,3-bis (4
-Aminoethyl) disiloxane, 1,1,3,3,5,
5-hexamethyl-1,5-bis (4-aminophenyl) trisiloxane, 1,1,3,3-tetraphenyl-1,3-bis (2-aminoethyl) disiloxane,
1,1,3,3-tetraphenyl-1,3-bis (3-
Aminopropyl) disiloxane, 1,1,5,5-tetraphenyl-3,3-dimethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,5,5-tetraphenyl-3, 3-dimethoxy-1,5-bis (4-
Aminobutyl) trisiloxane, 1,1,5,5-tetraphenyl-3,3-dimethoxy-1,5-bis (5-
Aminopentyl) trisiloxane, 1,1,3,3-tetramethyl-1,3-bis (2-aminoethyl) disiloxane, 1,1,3,3-tetramethyl-1,3-bis (3- Aminopropyl) disiloxane, 1,1,3,3
-Tetramethyl-1,3-bis (4-aminobutyl) disiloxane, 1,3-dimethyl-1,3-dimethoxy-
1,3-bis (4-aminobutyl) disiloxane, 1,
1,5,5-tetramethyl-3,3-dimethoxy-1,
5-bis (2-aminoethyl) trisiloxane, 1,
1,5,5-tetramethyl-3,3-dimethoxy-1,
5-bis (4-aminobutyl) trisiloxane, 1,
1,5,5-tetramethyl-3,3-dimethoxy-1,
5-bis (5-aminopentyl) trisiloxane, 1,
1,3,3,5,5-hexamethyl-1,5-bis (3
-Aminopropyl) trisiloxane, 1,1,3,3,3
5,5-hexaethyl-1,5-bis (3-aminopropyl) trisiloxane, 1,1,3,3,5,5-hexapropyl-1,5-bis (3-aminopropyl) trisiloxane, etc. Can be mentioned. The siloxane-based diamines may be used alone or in combination of two or more.

In the present invention, by using a diamine having at least one sulfone group, sulfoxide group or sulfide group in the molecule in addition to the siloxane-based diamine, the adhesiveness to the conductive metal layer can be improved. .

Specific examples of the above diamine include 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone,
4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) ) Phenyl] sulfone and the like.

In the present invention, other diamines can be added to the extent that the adhesiveness to the conductive metal layer is not deteriorated. Specific examples thereof include 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 4,4′-methylenebis (cyclohexylamine), 3,3′-methylenebis (cyclohexylamine), 4,4′-diamino-3, 3'-dimethyldicyclohexylmethane, 4,
4'-diamino-3,3'-dimethyldicyclohexyl, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,3'-
Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,5-diaminotoluene, o-tolidine, 3,3'-dimethyl-4,
4'-diaminodiphenylmethane, diaminobenzanilide, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis [4- (4-aminophenoxy)
Phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] methane, bis [4- (3-
Aminophenoxy) phenyl] methane, bis [4- (4
-Aminophenoxy) phenyl] ether, bis [4-
(3-Aminophenoxy) phenyl] ether, 2,2
-Bis [4- (4-aminophenoxy) phenyl] hexafluoropropane and the like. Of these, aromatic diamines are preferably used from the viewpoint of heat resistance.

In the present invention, polyamic acid is synthesized by a known method. For example, it can be synthesized by selectively combining a tetracarboxylic acid component and a diamine component and reacting them in a solvent at 0 to 80 ° C. in the above-mentioned predetermined molar ratio.

As a solvent for synthesizing the polyamic acid, an amide-based polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, β-propiolactone or γ-butyrolactone is used. , Γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, and other lactone polar solvents, and other examples include methyl cellosolve, ethyl cellosolve, methyl carbitol, and ethyl carbitol. These may be used alone or 2
You may use it in mixture of 2 or more types.

The polyamic acid concentration is usually 5 to 6
It is preferably 0% by weight, more preferably 10 to 40% by weight. The molecular weight of the polymer is adjusted by equimolar amounts of the tetracarboxylic acid component or the diamine component, or an excess of either one. When either the tetracarboxylic acid component or the diamine component is in excess, the polymer chain end may be capped with an end capping agent such as an acid component or an amine component. Generally, a dicarboxylic acid or an anhydride thereof is used as the end cap of the acid component, and a monoamine is used as the end cap of the amine component. At this time, it is preferable that the acid equivalent of the tetracarboxylic acid component including the end capping agent of the acid component or amine component and the amine equivalent of the diamine component are equimolar. Specific examples of the terminal blocking agent include benzoic acid, phthalic anhydride, tetrachlorophthalic anhydride, maleic anhydride, aniline and the like.

Further, organic or inorganic fine particles, filler, etc. may be added to these heat resistant resins. Specific examples of the fine particles and fillers include silica, alumina, titanium oxide, quartz powder, magnesium carbonate, potassium carbonate, barium sulfate and the like.

The heat-resistant insulating film used in the present invention has a melting point of 280 ° C. or higher, preferably 300 ° C. or higher, more preferably 350 ° C. or higher, or JI.
The polymer resin film may have a maximum allowable temperature of 121 ° C. or higher, preferably 150 ° C. or higher, and more preferably 200 ° C. or higher, which is defined by S C4003 for a long time. When the value is below the lower limit of the above numerical range, long-term heat resistance reliability is poor.

The thickness of the heat resistant insulating film is 3 to 150.
μm, preferably 5 μm to 75 μm, more preferably 5
μm to 50 μm. If it is less than the lower limit of the above numerical range, the strength as a support becomes insufficient, which is not preferable. On the other hand, when the value exceeds the upper limit of the above numerical range, flexibility becomes insufficient, and bending may be difficult, which is not preferable.

The heat-resistant insulating film in the present invention includes aromatic polyimide resin, polyphenylene sulfide resin, aromatic polyamide resin, polyamideimide resin, aromatic polyester resin, etc. , Toray DuPont Co., Ltd. "Kapton", Ube Industries, Ltd. "Upilex", Kanegafuchi Chemical Co., Ltd. "Apical", Toray Co., Ltd. "Miktron", Kuraray Co., Ltd. "Bekitra" And the like.
Among these, aromatic polyimide resins are particularly preferably used.

Further, it is preferable that one or both surfaces of the heat-resistant insulating film is subjected to adhesion improving treatment according to the purpose such as corona discharge treatment or low temperature plasma treatment. Adhesion can be improved by performing these treatments.

The discharge treatment is preferably a so-called normal pressure plasma treatment for discharging near atmospheric pressure, a corona discharge treatment, a low temperature plasma treatment, or the like.
By performing these treatments, the adhesiveness between the heat resistant insulating film made of a polyimide film or the like and the heat resistant resin layer can be significantly improved.

Atmospheric pressure plasma treatment means Ar, N ₂ , H
A method of performing discharge treatment in an atmosphere of e, CO ₂ , CO, air, steam or the like. The processing conditions vary depending on the processing equipment, type of processing gas, flow rate, frequency of power supply, etc.
Optimal conditions can be selected as appropriate.

The low temperature plasma treatment can be carried out under reduced pressure, and the method thereof is not particularly limited, but for example, in an internal electrode type discharge treatment apparatus having a counter electrode composed of a drum electrode and a plurality of rod electrodes. The substrate to be treated is set and the treatment gas is 1 to 1,000 Pa, preferably 5 to
There is a method in which a high voltage of DC or AC is applied between the electrodes in a state of being adjusted to 100 Pa to perform discharge to generate plasma of the processing gas, and the surface of the substrate is exposed to the plasma for processing. The conditions of the low-temperature plasma treatment vary depending on the treatment apparatus, the type of treatment gas, the pressure, the frequency of the power source, etc., but the optimum conditions can be selected as appropriate. The processing gas is not particularly limited, but Ar, N ₂ , He, CO ₂ , CO, air, water vapor, O ₂ , CF _4, etc. can be used alone or in combination.

On the other hand, since the corona discharge treatment is less effective in improving the adhesiveness than the low temperature plasma treatment, it is important to select an appropriate heat resistant resin layer to be laminated.

Next, the method for laminating the heat resistant insulating film and the heat resistant resin layer will be described in detail with reference to an example of obtaining the printed circuit board of the present invention. As a heat resistant insulating film, a solvent solution containing the above polyamic acid varnish is uniformly applied on a polyimide film that has been subjected to low temperature plasma treatment or corona discharge treatment to form a heat resistant resin layer. Examples of the coating method include a roll coater, a knife coater, a hermetic coater, a comma coater and a doctor blade float coater. Next, the solvent of the solution coated on the heat-resistant insulating film as described above is usually removed by heating continuously or intermittently at a temperature of 60 ° C. to 200 ° C. for 1 to 60 minutes.

The thickness of the heat resistant resin layer formed on the polyimide film which is the heat resistant insulating film is 0.05 to
The thickness is 10 μm, preferably 0.1 to 8 μm, and more preferably 0.3 to 6 μm, but it can be preferably selected according to the purpose.

Further, in order to improve the adhesiveness, it is preferable to further perform heat curing. The conditions for heating and curing are at a temperature of 200 ° C. to 350 ° C. for about 5 minutes to 30 minutes, and can be appropriately selected depending on the resin composition, film thickness, and the like.

The conductive metal layer in the present invention is not particularly limited as long as it is composed of a metal having excellent conductivity, and aluminum, copper, palladium, nickel, chromium, SUS, cobalt, gold, etc. The metal of the above can be mentioned alone or as an alloy.
Copper is preferable, and a main component layer such as a plating layer may be formed of copper. Further, the conductive metal layer may be multi-layered. For example, the metal may be thinly formed on the surface of the heat resistant resin layer by vapor deposition or sputtering, and the same or different metal layer may be formed thereon.

The form of the conductive metal layer, particularly the copper layer, is not particularly limited, but a plated layer is preferable from the viewpoint of easy control of the characteristics and thickness of the film. The plating layer is generally in a cross-sectional crystal image by an electron microscope,
Crystals developed in the thickness direction are observed. Typically, the length in the thickness direction of the crystal is preferably 90% or more, more preferably 95% or more of the layer thickness of the main component layer such as copper. Generally, a base layer of the main component layer has a different component different from that of the main component layer, a sputtered layer of the main component, and the like.

The electroplating method for forming the plating layer is not particularly limited, and a usual copper sulfate plating method may be used. In the case of a conductive metal layer, especially a copper layer, the thickness is 1 to 1
The range of 8 μm is preferable. If it is thinner than 1 μm, pinholes are likely to occur, and if it is thicker than 18 μm, it becomes difficult to control the thickness of the plated copper, which is not preferable. It is more preferably 3 μm or more and 12 μm or less.

The thickness of the heat resistant resin layer and the conductive metal layer can be measured by various methods. In the present invention, the film thickness of the heat resistant resin layer and the conductive resin layer can be measured by observing the cross section of the obtained printed circuit board with an SEM. In the case of a conductive metal layer, it can be calculated from the difference in film thickness between the portion where the conductive metal layer remains after etching the wiring pattern and the etched portion. In the case of the heat-resistant resin layer, it can be calculated by measuring the film thickness of the etched portion of the conductive metal layer of the printed circuit board and subtracting the known film thickness of the heat-resistant insulating film.

The conductive metal layer in the present invention preferably has a heterogeneous component layer usually made of nickel, chromium or the like on the side in contact with the heat resistant resin layer, and the thickness thereof is preferably 2 nm to 30 nm. is there. The different component layer may contain a main component (copper or the like), or may be distributed with a component concentration gradient in the thickness direction. After forming the layer, a copper layer is further laminated by sputtering or vapor deposition with a thickness of 50 nm or more, and in this case, the total thickness is preferably 400 nm or less. It is called a metal base layer, including a case where there is a main component (copper or the like) layer (hereinafter, simply referred to as a sputter main component layer) laminated on the heterogeneous component layer by sputtering or vapor deposition. That is, the metal base layer is composed of a different component layer or a different component layer / sputtering main component layer. When the main component layer is formed by plating, if the metal base layer is thinner than 2 nm, pinholes frequently occur, which is not preferable. If it is thicker than 400 nm, it takes a long time to form the conductive metal layer, which is not preferable. It is preferable to form a copper layer having a thickness of 1 to 18 μm on the conductive metal layer by electroplating.

The adhesive force in the present invention means a conductor width of 2 m.
50m in the direction of 90 degrees using the pattern of m
It means the value when peeled off at a speed of m / min. The "two-layer type plating" product in which a copper layer is laminated on the heat-resistant insulating film by a plating method has a flat adhesion interface of the copper layer, and an adhesion strength of about 5 N / cm is usually obtained by the above measuring method.

Since the printed circuit board of the present invention also has the metal layer formed by the plating method, the bonding interface of the metal layer is flat, but an adhesive force of 8 N / cm or more can be obtained as compared with the conventional one. It is possible. In addition, since the heat-resistant adhesive layer is very thin, it has an advantage of not impairing the inherent properties of the heat-resistant insulating film.

In the printed circuit board of the present invention, a resist layer is formed on the conductive metal layer of the printed circuit board,
By exposing and developing the resist layer, the resist is patterned into a shape that matches the wiring pattern, the conductive metal layer is etched using the patterned resist as an etching mask to form a wiring pattern, and the resist is removed after the wiring pattern is formed. It is obtained by doing so.

When the copper foil is etched, the cross section of the obtained wiring pattern of the printed circuit board is etched in the thickness direction as well as in the width direction (side etching). Has a narrower line width than that of the bottom (the surface in contact with the base film). As the thickness of the copper foil increases, the top line width tends to become narrower than the bottom line width. For example, in the case of a wiring pattern of 80 μm pitch (wiring width 40 μm, gap 40 μm),
When the top line width is 20 μm or more with respect to the bottom line width of 40 μm, a good pattern shape is obtained and no bonding failure occurs when the semiconductor is mounted. On the other hand, the top line width is 20μ
If it is smaller than m, defective bonding tends to occur when the semiconductor is mounted, which is not preferable.

Further, since the printed circuit board of the present invention has a metal layer on one side or both sides of the heat resistant insulating film, the wiring is formed by using the semi-additive method or the subtractive method, so that one side or both sides are formed. A wiring board can be formed.

[0054]

EXAMPLES The present invention will now be described in detail based on examples, but the present invention is not limited to these. In the following description, the adhesiveness, the heat load test, and the heat load test after tin plating were evaluated and measured by the following methods. (1) After laminating the adhesive metal layer, the metal layer was etched to a width of 2 mm with a ferric chloride solution, and the metal layer having a width of 2 mm was pulled at a pulling speed of 5 with "TENSILON" UTM-4-100 manufactured by TOYO BOLDWIN.
It was measured at 0 mm / min and 90 ° peeling. (2) Heat load test After laminating the metal layers, the metal layers were etched with a ferric chloride solution to a width of 2 mm, placed in a hot air oven set at 150 ° C. for 240 hours and then taken out, and the adhesiveness as described above was used. Was evaluated. (3) Heat load test after tin plating After laminating metal layers and etching the metal layers to a width of 2 mm with ferric chloride solution, tin plating solution L manufactured by Tokyo Ohka Co., Ltd.
Using T-34, electroless tin plating was performed at a liquid temperature of 70 ° C. for a plating time of 5 minutes, followed by washing with water and drying. It was placed in a hot air oven set at 150 ° C. for 240 hours and then taken out, and the adhesiveness as described above was evaluated.

Production Example 1 4488 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device, and bis (3
-Aminopropyl) tetramethyldisiloxane 248.5g
(1.0 mol), 4,4'-diaminodiphenyl ether 2
After dissolving 00.2g (1.0mol), 3,3 ', 4,4'
-Benzophenone tetracarboxylic acid dianhydride 386.6 g
(1.2 mol) and 28,6 g (0.8 mol) of 3,3 ', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride were added,
After stirring at 30 ° C. for 1 hour and stirring at 60 ° C. for 5 hours to cause a reaction, a 20 wt% polyamic acid adhesive solution (PA1) was obtained.

Production Example 2 4661 g of N, N-dimethylacetamide was placed in a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirrer, and bis (3
-Aminopropyl) tetramethyldisiloxane 248.5g
(1.0 mol), 4,4'-diaminodiphenyl ether 2
After dissolving 00.2g (1.0mol), 3,3 ', 4,4'
-Diphenylsulfone tetracarboxylic dianhydride 716.6
After adding g (2.0 mol) and stirring at 30 degreeC for 1 hour, it stirred at 60 degreeC for 5 hours, and was made to react, and the 20 weight% polyamic-acid adhesive agent solution (PA2) was obtained.

Production Example 3 4565 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device, and bis (3
-Aminopropyl) tetramethyldisiloxane 298.2g
(1.2 mol), 3,3'-diaminodiphenyl sulfone 1
After dissolving 98.6g (0.8mol), 3,3 ', 4,4'
-Benzophenone tetracarboxylic acid dianhydride 644.4 g
(2.0 mol) was added, and the mixture was stirred at 30 ° C for 1 hour and then at 60 ° C for 5 hours.
A 20% by weight polyamic acid adhesive solution (PA3) was obtained by reacting with stirring for a time.

Production Example 4 5449 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device, and bis (3
-Aminopropyl) tetramethyldisiloxane 198.8g
(0.8 mol) and bis (3-aminophenoxyphenyl) sulfone 519.0 g (1.2 mol) were dissolved, and then 3,3 ′,
4,4'-benzophenone tetracarboxylic acid dianhydride 6
After adding 44.4g (2.0mol) and stirring at 30 ℃ for 1 hour, 60
20% by weight by reacting by stirring for 5 hours at ℃
A polyamic acid adhesive solution (PA4) was obtained.

Production Example 5 4516 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirrer, and bis (3
-Aminopropyl) tetramethyldisiloxane 198.8g
(0.8mol), p-phenylenediamine 32.4g (0.3mo
l), 3,3'-diaminodiphenyl sulfone 198.6g
After dissolving (0.8 mol), 322.2 g (1.0 mol) of 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride
l), 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic acid dianhydride 358.3 g (1.0 mol) was added, and the temperature was 30 ° C.
After stirring for 1 hour at 60 ° C. for 3 hours to react,
Add 18.6g (0.2mol) of aniline and add 2 at 60 ℃.
By stirring for a time, a 20% by weight polyamic acid adhesive solution (PA5) was obtained.

Production Example 6 4453 g of N, N-dimethylacetamide was placed in a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirrer, and bis (3
-Aminopropyl) tetramethyldisiloxane 248.5g
(1.0 mol), 4,4'-diaminodiphenyl ether 2
After dissolving 00.2g (1.0mol), 3,3 ', 4,4'
-Benzophenone tetracarboxylic dianhydride 322.2 g
(1.0 mol) and 34,3 g (1.0 mol) of 3,3 ', 4,4'-diphenyl sulfoxide tetracarboxylic acid dianhydride were added, and the mixture was stirred at 30 ° C for 1 hour and then stirred at 60 ° C for 5 hours to react. As a result, a 20% by weight polyamic acid adhesive solution (PA6) was obtained.

Production Example 7 4037 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device, and bis (3
-Aminopropyl) tetramethyldisiloxane 248.5g
(1.0mol), p-phenylenediamine 108.1g (1.0mo
l) was dissolved, and then 652.6 g (2.0 mol) of 3,3 ′, 4,4′-diphenylsulfide tetracarboxylic dianhydride
l) was added, and the mixture was stirred at 30 ° C. for 1 hour and then reacted at 60 ° C. for 5 hours to obtain a 20 wt% polyamic acid adhesive solution (PA7).

Production Example 8 3796 g of N, N-dimethylacetamide was placed in a reaction vessel equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device, and bis (3
-Aminopropyl) tetramethyldisiloxane 142.3 g
(0.5mol), 162.2g of p-phenylenediamine (1.5mo
l) was dissolved, 644.4 g (2.0 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride was added, and the mixture was stirred at 30 ° C. for 1 hour and then at 60 ° C. for 5 hours. By reacting, a 20% by weight polyamic acid adhesive solution (PA8) was obtained.

Production Example 9 4428 g of N, N-dimethylacetamide was placed in a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirrer, and bis (3
-Aminopropyl) tetramethyldisiloxane 223.6g
(0.9 mol), 4,4'-diaminodiphenyl ether 2
After dissolving 20.3g (1.1mol), 3,3 ', 4,4'
-Benzophenone tetracarboxylic acid dianhydride 644.4 g
(2.0 mol) was added, and the mixture was stirred at 30 ° C for 1 hour and then at 60 ° C for 3 hours.
After reacting by stirring for 1 hour, 18.6 g (0.2 mol) of aniline was added and further stirred at 60 ° C. for 2 hours,
A 20% by weight polyamic acid adhesive solution (PA9) was obtained.

Example 1 The polyamic acid adhesive solution PA1 prepared in Production Example 1 was
25μ that was previously plasma-treated in Ar atmosphere at low temperature
m polyimide film (“Kapton” 100EN manufactured by Toray-Dupont Co., Ltd.) is coated with a bar coater so that the film thickness after drying is 3 μm, and dried at 100 ° C. for 5 minutes and further at 130 ° C. for 10 minutes. did. 30 minutes at 290 ° C
A heat treatment was performed for minutes to perform imidization and removal of residual solvent.

A Cr layer having a thickness of 10 nm was formed on the adhesive-coated surface of the above-prepared film using a sputtering device (SPL-500 manufactured by Nichiden Anelva Co., Ltd.), and then a copper layer having a thickness of 0.2 μm was formed thereon. It was laminated by sputtering. Immediately after sputtering, a copper sulfate bath was used to perform plating under a condition of a current density of 2 A / dm ^{2 so} that the copper thickness was 8 μm to obtain a printed circuit board.

Example 2 A printed circuit board was obtained in the same manner as in Example 1, except that the polyimide film was changed to "UPILEX" 25S manufactured by Ube Industries, Ltd.

Examples 3 to 13 Printed circuit boards were obtained in the same manner as in Example 1 except that the polyamic acid adhesive solution, the film thickness after drying, and the polyimide film were changed as shown in Table 1.

Comparative Examples 1 to 4 A printed circuit board was obtained in the same manner as in Example 1 except that the polyamic acid adhesive solution, the film thickness after drying, and the polyimide film were changed as shown in Table 1.

Comparative Example 5 A 25 μm polyimide film (“Kapton” 1 manufactured by Toray-Dupont Co., Ltd.) which was subjected to low temperature plasma treatment in an Ar atmosphere.
00EN) with the sputtering apparatus used in Example 1 to provide Cr with a thickness of 10 nm, and then 0.2 μm of copper thereon.
m sputtered. Immediately after sputtering, use a copper sulfate bath,
Copper was plated under the condition of current density of 2 A / dm ^{2 to} a copper thickness of 8 μm to obtain a printed circuit board.

Comparative Example 6 A printed circuit board was obtained in the same manner as in Comparative Example 5 except that the polyimide film was changed to "UPILEX" 25S manufactured by Ube Industries, Ltd.

The adhesive strength of the copper-plated products prepared so far was measured. The results are shown in Table 1. From this result, the products of the present invention have a strong adhesive force between the base film and the plated copper,
Moreover, there was little decrease in adhesive strength after heat loading at 150 ° C. for 240 hours, and there was no decrease in adhesive strength even after tin plating.

[0072]

[Table 1]

Example 14 A photoresist film was applied on a copper foil of a printed circuit board obtained in Example 1 by a reverse coater so that the film thickness after drying was 4 μm, and after drying, a wiring pattern was formed at a pitch of 80 μm (wiring). The mask was exposed to have a width of 40 μm and a gap width of 40 μm), a wiring pattern was formed with an alkali developing solution, and then the copper foil was wet-etched with an aqueous solution of ferric chloride. The remaining photoresist film was removed to form a copper wiring pattern to obtain a printed circuit board.

The wiring pattern of the printed circuit board obtained by the above method was observed with a microscope and the line widths of the bottom and top of the copper wiring were measured. The bottom line width was 39 μm and the top line width was 32 μm. A good wiring pattern could be obtained.

Comparative Example 7 (three-layer laminate product) Polyamide resin "Macromelt" 6030 250 g (50% by weight) manufactured by Henkel Japan KK, Epoxy resin "Epicoat" 828 105 g manufactured by Yuka Shell Epoxy Co., Ltd.
(21% by weight), phenol resin C manufactured by Showa Highpolymer Co., Ltd.
145 g of KM-1636 (29% by weight) was dissolved in 680 g of isopropyl alcohol and 1760 g of chlorobenzene to obtain a 17% by weight polyamide / epoxy / phenolic adhesive solution.

The polyamide / epoxy / phenolic adhesive solution thus obtained was preliminarily subjected to low-temperature plasma treatment in an argon atmosphere to form a polyimide film having a thickness of 25 μm (“Kapton” 100EN manufactured by Toray DuPont Co., Ltd.).
Then, it was coated with a reverse coater so that the film thickness after drying was 6 μm, and dried at 80 ° C. for 10 minutes and further at 130 ° C. for 30 minutes.

On the adhesive coated surface of the above prepared film, 80
After pre-drying at 5 ℃ for 5 minutes, electrolytic copper foil with a thickness of 18μm was heated to a surface temperature of 140 ℃, and the line pressure was 2kg.
/ cm, laminating at a speed of 1 m / min, and heating step cure under nitrogen atmosphere [(60 ° C, 30 min) + (100
C., 1 hour) + (160.degree. C., 2 hours)] and then cooled to room temperature to obtain a printed circuit board.

The same operation as in Example 14 was performed on the printed circuit board to obtain a printed circuit board. By observing the wiring pattern of the printed circuit board obtained by the above method with a microscope, the line width of the bottom and top of the copper wiring was measured,
The line width of the bottom was 38 μm and the line width of the top was 12 μm, and the shape of the wiring pattern was poor.

Comparative Example 8 (two-layer cast product) 2090 g of N, N-dimethylacetamide was placed in a reaction kettle equipped with a thermometer, a dry nitrogen inlet, a heating / cooling device with hot / cooling water, and a stirring device. 4,4 'under nitrogen stream
After dissolving 200.2 g (1.0 mol) of diaminodiphenyl ether, 322.2 g (1.0 mol) of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride was added, and 30
After stirring at 60 ° C. for 1 hour and stirring at 60 ° C. for 5 hours to cause a reaction, a 20% by weight polyamic acid solution was obtained. The obtained polyamic acid solution was applied to the uneven surface of an electrolytic copper foil having a thickness of 18 μm by a reverse coater so that the film thickness after curing would be 25 μm, and dried at 80 ° C. for 10 minutes and 140 ° C. for 30 minutes. . Then, it was heat-cured at 290 ° C. for 30 minutes to obtain a printed circuit board. The above printed circuit board was subjected to the same operations as in Example 14 to obtain a printed circuit board.

The wiring pattern of the printed circuit board obtained by the above method was observed with a microscope and the line widths of the bottom and top of the copper wiring were measured. The line width of the bottom was 41 μm and the line width of the top was 16 μm. The shape of the wiring pattern was poor.

[0081]

Since the present invention is constructed as described above,
It is possible to reliably obtain a plating-type circuit board material that has a high initial adhesive strength with the plated copper formed on the heat-resistant film and has an extremely small decrease in adhesive strength even after high-temperature heat load and tin plating.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/00 H05K 3/00 RF term (reference) 4F100 AB01C AB01E AB17C AB17E AK01A AK01B AK01D AK46B AK46D BA05 BA10A BA10C BA10E EH71C EH71E GB43 JG01C JG01E JG04A JJ03A JJ03B JJ03D JK06 4J043 PA02 QB15 QB26 QB31 RA35 SA06 TA22 UA131 UA132 UA672 UB282 UB292 UB302 UB351 VA062 VA102EE01 A01 ZB50 5E338

Claims (6)

[Claims] 1. A printed circuit board in which a heat-resistant resin layer / conductive metal layer is sequentially laminated on at least one surface of a heat-resistant insulating film, wherein the heat-resistant resin layer is at least one of a sulfone group, a sulfoxide group and a sulfide group. A printed circuit board, characterized in that the conductive metal layer is a plated layer. 2. The printed circuit board according to claim 1, wherein the heat resistant resin layer is a polyimide resin. 3. The print according to claim 2, wherein the polyimide-based resin contains an aromatic tetracarboxylic acid and a diamine as main components, and the diamine component contains a siloxane-based diamine represented by the following general formula (1). Circuit board. [Chemical 1] (In the formula, n represents an integer of 1 or more. Further, R ¹ and R ² may be the same or different and each represents a lower alkylene group or a phenylene group, and R ^{3 to} R ^3
6 may be the same or different and each represents a lower alkyl group, a phenyl group or a phenoxy group. ) 4. The thickness of the heat resistant resin layer is 0.05 to 10 μm.
2. The printed circuit board according to claim 1, wherein 5. The printed circuit board according to claim 1, wherein the conductive metal layer has a thickness in the range of 1 to 18 μm and is made of copper. 6. A printed circuit board using the printed circuit board according to claim 1.