TWI508852B - Method for manufacturing single side metal-clad laminate - Google Patents

Description

Method for manufacturing single-sided metal-clad laminate

The present invention relates to a method for producing a single-sided metal-clad laminate, which is a method for producing a single-sided metal-clad laminate obtained by bonding a metal foil to an insulating film having a bonding surface made of a thermoplastic resin.

In recent years, the use of flexible circuit boards has increased due to the miniaturization, light weight, and high performance of electrical equipment, such as thermoplastic polyimide films and liquid crystal polymer films on the surface. A metal-clad laminate formed by thermocompression metal foil on an insulating film is an example suitable for use. The laminated body having such a structure is generally manufactured by conveying an insulating film and a metal foil by a roll-to-roll method, and heating it while passing between a pair of pressing rollers. A method of performing thermal compression bonding continuously.

For example, in the proposal disclosed in Patent Document 1, when a metal foil is thermocompression-bonded on one surface of a sheet having a thermoplastic resin layer on both sides of a heat-resistant film, the pressing surface and the sheet of the thermocompression bonding apparatus are used. A method of preventing the thermoplastic resin layer on the side of the unlaminated metal foil from being welded to the metal roller and the protective film by disposing a protective material therebetween. However, in this method, due to the lack of a pressure buffering effect for uniform pressurization, particularly when a thin back sheet and a thin metal foil are used, due to uneven pressure, there is a non-adult part and then The weak portion is also likely to form a void between the layer of the adhesive sheet and the metal foil, and there is a defect that the appearance is poor such as wrinkles.

Further, in the proposal disclosed in Patent Document 2, when the liquid crystal polymer film is overlapped with the metal foil and thermally pressed by a metal pressure roller, the heat resistant resin is superposed on the surface in contact with the metal pressure roller. A method of producing a laminate by a film. According to this method, a heat-resistant resin film is interposed between the laminate and the roller for the purpose of production, so that a certain cushioning effect can be expected, but conversely, the heat transfer of the pressure roller to the heat transfer effect of the laminated body However, it is hindered, so that the adhesion between the metal foil and the liquid crystal polymer film is lowered, and uneven adhesion may occur.

Further, the proposal disclosed in Patent Document 3 is a method for producing a laminate in which a thermoplastic polymer film and a substrate are heat-treated between rolls, and simultaneously pressed, wherein a thermoplastic polymer film is followed. The body is superposed and pressed together in a state of being sandwiched by the covering material on both sides thereof, whereby the film and the adherend are strongly pressed in a short time. However, in this method, since the protective material is easily contacted by the direct contact between the protective material and the heated and pressed surface, the number of reuse of the protective material is reduced, and the manufacturing cost and the like are disadvantageous. At the same time, in the same manner as in Patent Document 1, when a thin thermoplastic polymer film and a thin adherend are used, there is a concern that it is easy to form a non-subsequent portion and a weakly succeeding portion, and may also occur. Interlayer voids, wrinkles, etc.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2008-272958

[Patent Document 2] WO2004/108397

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2001-88219

Therefore, an object of the present invention is to provide a good adhesion between layers of an insulating film and a metal foil, and to prevent unevenness in strength, to suppress occurrence of appearance defects such as wrinkles, and to produce a single-sided metal-clad layer with good industrial productivity. Body method.

As a result of intensive studies to solve the problems of the prior art described above, the present inventors have found that the combination of the insulating film and the metal foil is formed into two groups of upper and lower symmetry centering on the spacer film and superimposed thereon, and is subjected to hot pressing by a pressure roller. After the combination, there is no flaw in the film to be welded to the pressure roller, and since the pressure between the pressure rollers is more uniformly transmitted, uneven strength, wrinkles, and the like can be prevented, and if the film is peeled off from the spacer film, The present invention can be completed by obtaining two sets of single-sided metal-clad laminates of such quality stability at one time.

That is, the method for producing the single-sided metal-clad laminate according to the present invention is a single-sided metal-clad laminate in which an insulating film (A) having a bonding surface made of a thermoplastic resin is followed by a metal foil (B). The method is characterized in that the surface and the inner surface are both a film (C) having a surface roughness (Rz) of 2.0 μm or less, and (r1)/( between a pair of pressure rollers (r1, r2). In the order of B)/(A)/(C)/(A)/(B)/(r2), the insulating film (A), the metal foil (B), and the spacer film (C) are superposed and thermocompression bonded. Two single-sided metal-clad laminates were obtained by peeling off the spacer film (C).

According to the present invention, it is possible to produce a high-quality single-sided metal-clad laminate which is excellent in the adhesion between the insulating film and the metal foil without causing wrinkles and uneven strength, and which is excellent in industrial productivity. That is, the manufacturing method of the present invention can greatly improve the industrial production efficiency as compared with the conventional method, and thus a high-quality single-sided metal-clad laminate can be produced at a lower cost. Further, since the single-sided metal-clad laminate obtained by the present invention has high quality and excellent reliability, it can be suitably used as, for example, a circuit substrate required for forming a fine pattern, and a multilayer circuit substrate. Substrate material used.

The invention is described in detail below.

In the present invention, between a pair of pressing rollers (r1, r2), a metal foil (B) / an insulating film (A) / a spacer film (C) / an insulating film (A) / a metal foil ( The order of B) is superposed and thermocompression-bonded, and then peeled off from the spacer film (C), and two single-sided metal-clad laminates obtained by adhering the metal foil (B) to the insulating film (A) are simultaneously produced.

In addition, the insulating film (A) used in the present invention is not particularly limited as long as it has a bonding surface made of a thermoplastic resin and can be bonded to the bonding surface via a thermocompression bonding. For example, i) is composed of a thermoplastic resin film; and other, for example, ii) a thermoplastic resin layer is provided on one surface of the heat resistant resin film to form a bonding surface; and iii) a heat resistant resin film is formed. A thermoplastic resin layer is provided on both surfaces, and any one of them is used as a back surface of the metal foil. Further, one or two or more of them may be used to form a plurality of layers.

In the examples of the insulating film (A) composed of a thermoplastic resin film, for example, polyethylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile/ A styrene copolymer resin, a thermoplastic polythene resin, a liquid crystal polymer or the like is preferable, and a liquid crystal polymer or a thermoplastic polythene resin is preferable from the viewpoints of workability, electrical properties, heat resistance and the like.

Examples of the liquid crystal polymer include well-known thermotropic liquid crystal polyesters and thermotropic liquid crystal polyesters derived from the compounds classified by the following (1) to (4) and derivatives thereof. Amines, etc.

(1) aromatic or aliphatic dihydroxy compounds

(2) aromatic or aliphatic dicarboxylic acid

(3) Aromatic hydroxycarboxylic acid

(4) aromatic diamine, aromatic hydroxylamine or aromatic aminocarboxylic acid

Among the liquid crystal polymers obtained by such a raw material compound, an aromatic liquid crystal polymer containing no aliphatic chain in the molecule is preferable. Representative examples of such a liquid crystal polymer include a copolymer prepared by using 6-hydroxy-2-naphthoic acid and p-hydroxybenzoic acid as raw materials and containing a constituent unit represented by the following formula. Here, m ₂ and n ₂ in the following formula are positive numbers showing the molar ratio of each constituent unit.

In the liquid crystal polymer, optical anisotropy is preferably in the range of 200 to 400 ° C, more preferably in the range of 250 to 350 ° C, in consideration of heat resistance and workability at the time of thermocompression bonding. The transfer temperature of the molten phase of (optically anisotropy) is preferred. Further, in the liquid crystal polymer, a lubricant, an antioxidant, a filler, and the like may be blended in a range that does not detract from the characteristics.

The method of thinning the liquid crystal polymer may, for example, be a T die method, a laminate stretching method, an inflation method or the like. In the case where the inflation method and the laminate stretching method are used, stress is not applied only in the mechanical axis direction (MD direction) of the film, and stress is applied in the direction perpendicular thereto (TD direction), so that the MD direction can be made. A film that balances the mechanical properties of the TD direction. Commercially available products such as Vecstar (registered trademark) manufactured by KURARAY Co., Ltd., and BIAC and STABIAX (both registered trademarks) manufactured by GORE-TEX Corporation of Japan may be used as the liquid crystal polymer film.

Further, the thermoplastic polyimide resin can be formed by ruthenium (hardening) the polyamic acid of its precursor, wherein the polyamine can be obtained by using a generally known diamine and an acid anhydride. It is prepared by carrying out a reaction in the presence of a solvent.

The precursor used in the thermoplastic polyimide resin is preferably a precursor having a structural unit represented by the following formula (1). In the formula (1), Ar ₃ represents a divalent aryl group represented by the formula (2), the formula (3) or the formula (4); and Ar ₄ represents a tetravalent aromatic group represented by the formula (5) or the formula (6). R ₂ is independently a monovalent hydrocarbon group or alkoxy group having 1 to 6 carbon atoms; V and W independently represent a single bond or a divalent hydrocarbon group selected from 1 to 15 carbon atoms, O, S, CO a divalent group in SO ₂ or CONH; m ₁ independently represents an integer of 0 to 4; and p represents a molar ratio of the constituent units, which is a value of 0.1 to 1.0.

The diamine used therein may, for example, be 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'-diaminobenzimidamide, 1,4-bis (4) -aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)benzene]propane, 2,2 '-Dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzimidamide, and the like. Examples of the acid anhydride include pyromellitic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, and 3,3',4,4'-diphenylanthracene. Tetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, and the like. The diamine and the acid anhydride may be used alone or in combination of two or more. The polyimine resin is not limited to those made of the above-described diamine and acid anhydride.

In the insulating film (A), when a thermoplastic polyimide film is used, the film can be generally known from tentering and casting methods of polyamic acid of a polyimide resin precursor. The method is to make it thin. One of the representative methods of the tenter method is to cast a polyaminic acid solution to a rotating roller, peel off from the rotating roller in the state of a colloidal acid colloidal film, and then pass through a tenter oven. A method of forming a polyimide film by heating/hardening (醯imination). The casting method is a method in which a polyaminic acid solution is coated and dried on an arbitrary supporting substrate, and then cured by heat treatment to obtain a polyimide film. The ruthenium imidization can be carried out, for example, by heating at a temperature of from 80 to 400 ° C for a period of from 1 to 60 minutes. Further, the polyimine resin may be formulated with, for example, a lubricant, an antioxidant, a filler, or the like, within a range not detracting from its characteristics.

In the insulating film (A), when ii) a thermoplastic resin layer is provided on one surface of the heat-resistant resin film, or iii) a thermoplastic resin layer is provided on both surfaces of the heat-resistant resin film, the heat-resistant resin film is only required The heat distortion temperature is preferably higher than that of the thermoplastic resin layer, and is not particularly limited, and a non-thermoplastic polyimide film is preferred. The non-thermoplastic polyimine resin is the same as the thermoplastic polyimine, and can be produced by reacting a generally known diamine with an acid anhydride in the presence of a solvent, which can be produced by changing the combination of raw materials used therein. Heat resistant polyimide resin. The non-thermoplastic polyimide film is commercially available, and examples thereof include Kapton EN, Kapton H, and Kapton V (all trade names) manufactured by Du Pont-Toray Co., Ltd.; and APICAL NPI manufactured by Zhongyuan Chemical Co., Ltd. Name); UPILEX-S (trade name) manufactured by Ube Industries Co., Ltd., etc. The non-thermoplastic polyimide film is preferably one having a glass transition temperature of 300 ° C or more, and preferably not deformed at a temperature of thermal compression by a roller.

In addition, the thermoplastic resin layer provided on one surface or both surfaces of the heat-resistant resin film may be formed of a resin having a glass transition temperature at least below the heating temperature of the thermocompression bonding, and the type of the resin is not particularly limited. The examples thereof include, for example, a thermoplastic polythene resin, a thermoplastic liquid crystal polymer, polyether ether ketone, polyethylene naphthalate, and the like. Further, the thermoplastic resin layer can be formed by bonding a thermoplastic resin film to a heat-resistant resin film, or can be formed by applying a precursor to a filming method or the like.

The thickness of the insulating film (A) is preferably 5 to 200 μm, more preferably 10 to 100 μm. When the insulating film (A) is too thin, the rigidity is reduced, and defects such as wrinkles and cracks occur in the manufacturing steps of the metal-clad laminate and in the processing steps of the wiring board using the obtained laminate. On the other hand, when it is too thick, the insulating film lacks flexibility, and in the manufacturing step of the metal-clad laminate, the roller-to-roll conveyance is difficult, and in addition, it may occur. The wiring board processed by the circuit is not easily loaded into a narrow frame or the like.

The material of the metal foil (B) used in the present invention is not particularly limited, and examples thereof include gold, silver, copper, stainless steel, nickel, aluminum, and the like. Among them, copper foil and stainless steel foil are preferable from the viewpoints of conductivity, ease of handling, and price. Among them, the copper foil can be produced by any of a rolling process and an electrolytic method. Further, for the purpose of improving the adhesion between the metal foil and the insulating film, physical surface treatment such as roughening treatment, and chemical surface treatment such as pickling, UV treatment, and plasma treatment may be performed in advance.

The thickness of the metal foil (B) is preferably from 1 to 100 μm, more preferably from 5 to 70 μm, still more preferably in the range of from 8 to 20 μm. If the thickness of the metal foil is reduced, it is preferable from the viewpoint of easily forming a fine pattern in circuit processing, but when it is too thin, not only wrinkles are easily formed in the metal foil in the manufacturing step of the metal-clad laminate, but also in the circuit. In the processed wiring board, wiring breakage is also likely to occur, and there is a concern that the reliability of the wiring board is degraded. Conversely, when it is too thick, when the metal foil is etched to form a circuit, taper is likely to occur on the side of the circuit, which is disadvantageous for the formation of the fine pattern.

The spacer film (C) used in the present invention must be easily peeled off from the insulating film (A) after thermocompression bonding in addition to heat resistance at a heat-resistant pressure bonding temperature. From the viewpoint of the latter, the surface and the inner surface of the spacer film (C) are preferably those having a surface roughness (Rz) of 2.0 μm or less, more preferably 0.5 to 1.5 μm. The spacer film (C) is preferably a heat-resistant resin film such as a non-thermoplastic polyimide film or a polyimide film, or a metal foil such as an aluminum foil or a stainless steel foil, in order to ensure heat resistance and surface smoothness at the same time. Further, a composite film having a metal foil on the surface and the inner surface of the resin film may also be used. When the surface roughness and the surface roughness (Rz) of the inner surface and the inner surface of the spacer film (C) exceed 2.0 μm, the interlayer adhesion between the insulating film (A) and the spacer film (C) is improved by the anchoring effect. When the single-sided metal-clad laminate made of the insulating film (A) and the metal foil (B) is peeled off when peeled off from the spacer film (C), the single-sided metal-clad laminate is broken. And wrinkles and other defects in appearance.

It is preferable that the spacer film (C) is subjected to release treatment on one side or both sides of the spacer film (C) for the purpose of increasing the peeling property after the thermocompression bonding and the insulating film (A). Specific examples of the release treatment include a method of providing a heat-resistant release resin film such as a silicone resin or a fluorine resin on the spacer film (C).

The thickness of the spacer film (C) is preferably from 10 to 300 μm, more preferably from 20 to 150 μm, still more preferably from 30 to 100 μm. When the spacer film (C) is too thin, the pressure buffering effect of uniformly dispersing the pressure during the thermocompression bonding is lowered, and the insulating film (A) of the metal-clad laminate formed and the layer of the metal foil (B) are closely adhered. Sex will have uneven considerations. On the other hand, when it is too thick, the conveyance of the roller to the roller may be hindered, or the workability may be deteriorated when peeling off from the metal-clad laminate after the thermocompression bonding.

In the combination of the insulating film (A), the metal foil (B), and the spacer film (C), the ease of handling and economy in the thermocompression bonding step (material cost, reusability of the spacer film, etc.) From the viewpoint of the characteristics (mechanical properties, electrical properties, thermal properties, processability, etc.) of the produced single-sided metal-clad laminate, it is preferred that the insulating film (A) is a liquid crystal having a thickness of 10 to 100 μm. a polymer film or a polyimide film having a thermoplastic resin layer on at least one of the surfaces; a metal foil (B) using a copper foil having a thickness of 5 to 70 μm; and a spacer film (C) using a surface and an inner surface All are aluminum foils having a surface roughness (Rz) of 2.0 μm or less and a thickness of 5 to 70 μm.

Insulation in the order of (r1) / (B) / (A) / (C) / (A) / (B) / (r2) between a pair of pressure rollers (r1, r2) When the film (A), the metal foil (B), and the spacer film (C) are thermocompression-bonded, a generally known heating and pressurizing device having a pressure roller having one pair of heating devices can be used. In this case, when the insulating film (A), the metal foil (B), and the spacer film (C) are each used in combination with a heating and pressurizing device, a single-sided coating can be continuously produced. Metal laminate. Further, the temperature of the pressure roller and the pressure condition of the pressure roller are not particularly limited. However, since the thermoplastic resin of the insulating film (A) must be well adhered to the metal foil (B) by deformation or the like, It is preferred to operate at a temperature slightly lower than the Tg or melting point of the thermoplastic resin. For example, when the insulating film (A) is a liquid crystal polymer film, it is preferably in a temperature range of 5 to 100 ° C lower than the melting point thereof, and more preferably in a temperature range of 20 to 80 ° C lower than the melting point. Further, it is more preferable that the pressurizing pressure is in the range of 20 to 200 kN/m.

In the present invention, the insulating film (A) and the metal foil (B) which are disposed on both sides of the spacer film (C) are disposed at a symmetrical position around the spacer film (C). Therefore, the pair of pressing rollers (r1, r2) can be thermocompression-bonded at the same temperature, thereby preventing unnecessary heat loss between the rollers. Further, since the pressure roller is in contact with the metal foil (B), heat conduction on the pressure roller is not easily hindered. Further, after thermocompression bonding, as described in the following examples, the interlayer peeling strength of the insulating film (A) and the spacer film (C) is 0.1 kN/m or less, and it is extremely easy to peel off, thereby preventing the subsequent peeling. Since uneven strength and wrinkles occur, a high-quality single-sided metal-clad laminate can be obtained with good productivity. Further, although the present invention obtains a single-sided metal-clad laminate from the two sets of the insulating film (A) and the metal foil (B) by interposing the spacer film (C), it is also possible to further evaluate the spacer film by interposing (C) A two-layered (B)/(A)/(B) combination was used, and two modified double-sided metal-clad laminates having metal foils on both sides were produced at one time.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following. Further, in the examples of the invention to be described later, the conditions of the processing conditions and the measurement (evaluation) are as described below unless otherwise specified.

[Measurement of surface roughness]

Rz (ten-point average thickness) was measured in accordance with JIS B 0601 using a stylus type surface roughness measuring instrument (TENCOR P-10, manufactured by TENCOR Co., Ltd.) under the conditions of a load of 100 μN, a scanning speed of 20 μm/sec, and a measurement distance of 800 μm. .

[Evaluation of the peelability of the spacer film (C)]

The laminate (B/A/C/A/B) containing the spacer film (C) after thermocompression bonding is cut into a width of 10 mm in the longitudinal direction of the press roller, and the direction of lamination is performed (MD) The direction was cut into a length of 150 mm to prepare a strip-like peeling test piece, and the interlayer peeling property of the insulating film (A) and the spacer film (C) was measured in accordance with JIS K 6854-3 (T-type peeling). The peeling speed was set at 100 mm/min.

[Evaluation of the adhesion of metal-clad laminates]

The obtained single-sided metal-clad laminate was cut into a length of 150 mm in the direction of lamination, and was etched by a subtractive method using a commercially available etching solution (ADEKA CHELUMICA FE-210, manufactured by ADEKA AG). The copper foil was formed along the direction in which the lamination was performed to form a linear conductor pattern 7 having a width of 1 mm and a length of 100 mm (refer to Fig. 3). In the linear conductor pattern 7, three patterns are formed at a central position in the width direction of the single-sided metal-clad laminate (longitudinal direction of the pressure roller), and three points are formed at a position spaced apart from each other by 30 mm from the center to the width direction. Adhesion test piece. The three linear conductor patterns of the adhesion test piece were measured for the strength of peeling from the insulating film (A) in accordance with Method B of JIS C 6471 8.1 (stretching in the 180° direction). After that, the average of the peel strengths of the three strips is preferably 1.0 kN/m or more, and 0.5 kN/m or more and less than 1.0 kN/m is acceptable, and when it is less than 0.5 kN/m, it is a bad grade of 3. Evaluate its "adhesiveness". In addition, the difference between the maximum value and the minimum value of the peel strengths of the three pieces was evaluated as "the degree of unevenness of the adhesion".

(Example 1)

A liquid crystal polymer film 1 (melting point 320 ° C) having a thickness of 50 μm and a width of 70 mm was rolled into a roll-shaped elongated film as an insulating film (A), and a commercially available thickness of 12 μm and a width of 70 mm was prepared. The electrodeposited copper foil 2 (surface roughness Rz: 1.6 μm of the insulating film layer and 1.4 μm of the exposed surface) is rolled into a roll-shaped elongated copper foil as a metal foil (B), and then prepared to have a thickness of 50 μm and a width of A 70 mm aluminum foil 3 (the surface and the inner surface are both surface roughness Rz: 1.2 μm) is rolled into a roll-shaped elongated aluminum foil as a spacer film (C). As shown in Fig. 1, these are respectively attached to the insulating film feeding roller A, the metal foil feeding roller B, the spacer film feeding roller C, and the pair of pressing rollers 4 (r1, r2). The film is superimposed and supplied in the order of "electrolytic copper foil 2 / liquid crystal polymer film 1 / aluminum foil 3 / liquid crystal polymer film 1 / electrolytic copper foil 2" (as shown in Fig. 2), which is naturally cooled by hot pressing And the aluminum foil 3 and the liquid crystal polymer film 1 are peeled off by using the peeling roller 6, and the aluminum foil 3 is recovered by the spacer film winding roller C', and the single-sided copper coating of the liquid crystal polymer film 1 and the electrolytic copper foil 2 is bonded. The laminated bodies 5 are each recovered by the product take-up rolls x provided at two places.

Thereafter, the electrolytic copper foil 2, the liquid crystal polymer film 1, and the aluminum foil 3 are all moved at a speed of 0.7 m/min, and between the two pressure rollers 4 each having a surface temperature of 240 ° C, with the roller between them The pressure is 40kN/m for thermocompression bonding, and after hot pressing, the laminate is cooled by natural cooling, and the aluminum foil 3 is recovered by the spacer film winding roller C', and is recovered by the product winding roller x disposed at two places. The one-sided copper clad laminate 5 of the first embodiment. The pressurizing roller 4 of the apparatus used in the first embodiment is composed of a carbon steel metal roller having a length of 130 mm and a roller diameter of 150 mm.

In the above-mentioned first embodiment, the interlayer peeling of the liquid-polymer polymer film 1 and the aluminum foil 3 after the thermocompression bonding was carried out extremely smoothly without any defects, and the liquid crystal polymer of the recovered single-sided copper-clad laminate 5 was visually observed. When the film surface and the electrodeposited copper foil surface were not confirmed, cracking, wrinkles, and surface roughness were not observed. In the manufacturing process, the single-sided copper-clad laminate 5 of the first embodiment is subjected to hot-pressing by the pressure roller 4 and before being fed to the peeling roller 6, the peeling test piece is cut, and the liquid crystal polymer film 1 and the aluminum foil are measured. As a result of the interlaminar peelability of 3, it was confirmed that the value of the interfacial peeling was unmeasurable, and it was excellently peeled off. In addition, one of the single-sided copper-clad laminates 5 recovered from the two was subjected to the above-described operation to form an adhesion test piece, and the adhesion between the liquid crystal polymer film 1 and the electrolytic copper foil 2 was evaluated. The "adhesiveness" evaluated based on the average of the peel strengths obtained from the three linear conductor patterns was good. In addition, the "degree of unevenness in adhesion" obtained from the difference between the maximum value and the minimum value of the peel strengths of the three strips was 0.03 kN/m, and it was confirmed that the liquid crystal polymer film 1 and the electrolytic copper foil 2 were The surface is evenly followed. The results are shown in Table 1.

(Example 2)

Except for the spacer film (C), a non-thermoplastic commercially available heat-resistant polyimide film 3 having a thickness of 50 μm (Tg: 340 ° C, surface and inner surface are both roughness Rz: 0.9 μm) was used. 1 A single-sided metal-clad laminate of Example 2 was obtained in the same manner.

In the second embodiment, the interlayer peeling of the liquid crystal polymer film 1 and the heat-resistant polyimide film 3 after the thermocompression bonding was carried out extremely smoothly without any defects, and the recovered single-sided copper-clad laminate 5 was visually observed. On the surface and the inner surface, cracks, wrinkles, and rough surfaces were not confirmed at all. Further, in the measurement using the peeling test piece, it was confirmed that the interfacial peeling was 0.07 kN/m. In addition, in the evaluation based on the adhesion test piece, the "adhesiveness" was good, and the "degree of unevenness of adhesion" was 0.02 kN/m, and it was confirmed that the liquid crystal polymer film 1 and the electrolytic copper foil 2 were The surface is evenly followed. The results are shown in Table 1.

(Example 3)

Example 3 was carried out in the same manner as in Example 1 except that the spacer film (C) was a double-sided copper-clad laminate (ESPANEX M series product (MB12-25-12CEG) manufactured by Nippon Steel Chemical Co., Ltd.). Single-sided copper-clad laminate. The double-sided copper-clad laminate has a polyimide film having a thickness of 25 μm as an insulating layer at its center, and a copper foil having a thickness of 12 μm is provided on both surfaces thereof, and the surface roughness (Rz) of the exposed surface of the copper foil is It is 1.0 μm.

In the production of the third embodiment, the interlayer peeling of the liquid crystal polymer film 1 and the heat-resistant polyimide film 3 after the thermocompression bonding was carried out extremely smoothly without any defects, and the recovered single-sided copper-clad laminate was visually observed. When the surface and the inner surface of the body 5 were not found, cracks, wrinkles, and rough surfaces were not observed at all. In addition, in the measurement using the peeling test piece, it was confirmed that the interface peeling was 0.04 kN/m; in the evaluation based on the adhesion test piece, the "adhesiveness" was good, and the "degree of unevenness of adhesion" was 0.03. kN/m, and it was confirmed that the single-sided copper-clad laminate 5 was uniformly followed in the plane. The results are shown in Table 1.

(Comparative Example 1)

A single-sided copper-clad laminate of Comparative Example 1 was obtained in the same manner as in Example 1 except that the spacer film (C) was a composite polyimide film having a thickness of 25 μm and a thermoplastic polyimide layer having a surface and an inner surface. body. The composite polyimine film is formed by setting a thermoplastic polyylide waist of about 2 μm on both sides of a non-thermoplastic polyimide of about 21 μm, and the surface and the inner surface of the thermoplastic polyimide. The thickness (Rz) was 2.3 μm.

In the comparative example 1, the composite polyimide film used as the spacer film was not peeled off smoothly from the liquid crystal polymer film 1 after the hot pressing, and it was confirmed to be 0.50 kN/m in the measurement using the peeling test piece. Cohesive failure. Further, when the surface and the inner surface of the recovered single-sided copper-clad laminate 5 were visually observed, the roughness of the surface of the liquid crystal polymer film was confirmed to be rough due to aggregation failure. On the other hand, in the evaluation based on the adhesion test piece, although the "adhesiveness" is acceptable, the "degree of unevenness of adhesion" is 0.15 kN/m, which is compared with the results of the examples. The adhesion in the plane of the single-sided copper clad laminate 5 is uneven. The results are shown in Table 1.

(Comparative Example 2)

A single-sided copper-clad laminate of Comparative Example 2 was produced in the same manner as in Example 1 except that the spacer film (C) was not used, and the single-sided copper-clad laminate was intended to be laminated after being subjected to hot pressing and cooling. The liquid crystal polymer film 1 used as the insulating film (A) was thermally welded to each other, and was 0.70 kN/m in the measurement of the peeling test piece, and the aggregation failure was confirmed. Further, after the obtained single-sided copper-clad laminate was visually observed, the surface of the liquid crystal polymer film was roughened due to aggregation failure, and a single-sided copper-clad laminate having a good appearance could not be obtained.

(Comparative Example 3)

The single surface of Comparative Example 3 was prepared in the same manner as in Example 1 except that the "electrolytic copper foil 2 / liquid crystal polymer film 1 / aluminum foil 3" was superposed between the pair of pressure rollers 4 in the same order. Copper laminate.

In the comparative example 3, only one single-sided copper-clad laminate was obtained, but the interlayer peeling of the liquid-polymer polymer film 1 and the aluminum foil 3 after the thermocompression bonding was smoothly performed, and the single-sided copper-clad laminate was recovered. The surface and the inner surface of the body 5 were not confirmed to have cracks, wrinkles, or rough surfaces. Further, in the measurement by the peeling test piece, it was confirmed that the interface peeling was 0.01 kN/m, and in the evaluation based on the adhesion test piece, "adhesiveness" was acceptable. However, the "degree of unevenness in adhesion" was 0.17 kN/m, and as compared with the results of the examples, it was found that the in-plane uniformity was not good.

(Comparative Example 4)

The same procedure as in Example 1 was carried out except that the "aluminum foil 3 / the electrolytic copper foil 2 / the liquid crystal polymer film 1 / the aluminum foil 3" were overlapped between the pair of pressure rollers 4, and the comparative example 4 was produced. Single-sided copper-clad laminate.

In Comparative Example 4, only one single-sided copper-clad laminate was produced in the same manner as in Comparative Example 3, but the interlayer peeling of the liquid-polymer polymer film 1 and the aluminum foil 3 after the thermocompression bonding was smoothly performed and recovered. The surface and the inner surface of the single-sided copper-clad laminate 5 were completely free from cracks, wrinkles, and rough surfaces. In the measurement by the peeling test piece, it was confirmed that the interface peeling was 0.01 kN/m, and the "adhesiveness" was good in the evaluation based on the adhesion test piece. However, the "unevenness of adhesion" was 0.07 kN/m, and as compared with the results of the examples, it was found that the uniformity in the in-plane was not good.

From the above results, according to the production method of the present invention, it is possible to produce a high-quality single-sided surface which is excellent in industrial strength and which does not cause wrinkles and subsequent unevenness, and which has excellent adhesion between the insulating film and the metal foil. Metal-clad laminate. Further, the present invention is not limited to the above embodiments, and various changes can be made.

1‧‧‧Liquid polymer film (insulating film (A))

2‧‧‧Electrolytic copper foil (metal foil (B))

3‧‧‧Aluminum foil (spacer film (C))

4‧‧‧Pressure roller

5‧‧‧Single-sided copper-clad laminate

6‧‧‧ peeling roller

7‧‧‧Line conductor pattern

A‧‧‧Insulating film feed roller

B‧‧‧metal foil feeding roller

C‧‧‧ spacer film feed roller

C'‧‧‧ spacer film take-up roller

MD‧‧‧Layer direction

R1, r2‧‧‧ pair of pressure rollers

x‧‧‧Product take-up roller

Fig. 1 is a side view showing a manufacturing apparatus of a single-sided metal-clad laminate according to an embodiment of the present invention.

Fig. 2 is a schematic view showing the vicinity of the pressure roller.

Fig. 3 is a plan view showing the test piece used in the evaluation of the adhesion between the insulating film and the metal foil.

1. . . Liquid crystal polymer film (insulating film (A))

2. . . Electrolytic copper foil (metal foil (B))

3. . . Aluminum foil (spacer film (C))

4. . . Pressurized roller

5. . . Single-sided copper-clad laminate

6. . . Stripping roller

A. . . Insulating film feed roller

B. . . Metal foil feeding roller

C. . . Spacer film feed roller

C’. . . Spacer film take-up roller

MD. . . Lamination direction

R1, r2. . . Pair of pressure rollers

x. . . Product take-up roller

Claims (6)

A method for producing a single-sided metal-clad laminate, which is a method for producing a single-sided metal-clad laminate having a metal foil followed by an insulating film having a bonding surface made of a thermoplastic resin, characterized in that the surface is used and The inner surface is a spacer film having a surface roughness (Rz) of 2.0 μm or less, and one of the pressure rollers/the aforementioned metal foil/the aforementioned insulating film/the aforementioned spacer film/the aforementioned insulation between the pair of pressure rollers In the order of the film/the metal foil/the other pressure roller, the insulating film, the metal foil, and the spacer film are laminated and thermocompression-bonded, and then peeled off from the spacer film to obtain two single-sided metal-clad laminates. The method for producing a single-sided metal-clad laminate according to the first aspect of the invention, wherein the insulating film is composed of a thermoplastic liquid crystal polymer film or a heat-resistant resin film having a thermoplastic resin layer on at least one surface thereof. . The method for producing a single-sided metal-clad laminate according to the first or second aspect, wherein the spacer film is composed of an aluminum foil, a heat-resistant resin film, or a composite of a metal foil on a surface and an inner surface of the resin film. The film is composed of. The method for producing a single-sided metal-clad laminate according to the first or second aspect of the invention, wherein the one or both sides of the spacer film are subjected to a release treatment. The method for producing a single-sided metal-clad laminate according to claim 1 or 2, wherein the metal foil is copper having a thickness of 1 to 100 μm. Foil. The method for producing a single-sided metal-clad laminate according to the first or second aspect of the invention, wherein the interlayer insulating strength between the insulating film and the spacer film after thermocompression bonding is 0.1 kN/m or less.