JP2014128913A - Method for manufacturing double-sided metal-clad laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a double-sided metal-clad laminate that realizes the manufacture of a double-sided metal-clad laminate having excellent interlayer adhesion between an insulation film and a metal foil and having no variations in adhesive strength with industrially good productivity while suppressing the occurence of appearance defects such as wrinkles and the like.SOLUTION: In the method for manufacturing a double-sided metal-clad laminate having metal foil (B, B') adhesively bonded to both sides of an insulation film (A) having an adhesive surface comprising a thermoplastic resin, the double-sided metal-clad laminate is produced by, using a divider film (C) having a heat capacity in a range of 50-150 J/m, laminating the insulation film (A), the metal foils (B, B') and the divider film (C) in the order of (r)/(B)/(A)/(B')/(C)/(B')/(A)/(B)/(r) between a pair of pressure rollers (r, r), followed by thermal compression bonding and then separating from the divider film (C) to obtain two double-sided metal-clad laminates.

Description

  The present invention relates to a method for producing a double-sided metal-clad laminate in which a metal foil is bonded to both sides of an insulating film having an adhesive surface made of a thermoplastic resin.

  With the recent reduction in size, weight and functionality of electrical devices, the use of flexible circuit boards has increased. For example, metal foil is applied to insulating films such as polyimide films and liquid crystal polymer films whose surfaces are thermoplastic. A crimped metal-clad laminate is preferably used. As a method for producing a laminate having such a structure, a method in which an insulating film and a metal foil are conveyed by a roll-to-roll method and continuously heat-pressed through a pair of pressure rolls while being heated is generally employed. Has been.

  For example, in Patent Document 1, when a metal foil is thermocompression bonded to one side of an adhesive sheet having a thermoplastic resin layer on both sides of a heat resistant film, a protective material is provided between the pressure surface of the thermocompression bonding apparatus and the adhesive sheet. There has been proposed a method for preventing the thermoplastic resin layer on the side where the metal foil is not laminated from being fused to a metal roll or a protective film. However, in this method, the pressure buffering effect for uniformly applying pressure is poor, and particularly when a thin adhesive sheet or a thin metal foil is used, an unadhered portion or a portion with low adhesive strength is generated due to pressure variation. In addition to this, there is a problem that voids are formed between the adhesive sheet and the metal foil, resulting in appearance defects such as wrinkles.

  Further, in Patent Document 2, when a liquid crystal polymer film and a metal foil are overlapped and thermocompression bonded with a metal pressure roll, a heat resistant resin film is further overlapped and laminated on the side in contact with the metal pressure roll. A method of manufacturing a body has been proposed. According to this method, since a heat-resistant resin film is interposed between the laminate for production and the roll, a certain buffering effect can be expected, but conversely, the heat of the pressure roll is transmitted to the laminate. The thermal effect is hindered, and there is a possibility that the adhesive force between the metal foil and the liquid crystal polymer film is lowered or the adhesive force varies.

  Further, in Patent Document 3, in a method for producing a laminate in which a thermoplastic polymer film and an adherend are pressure-bonded while being heat-treated between rolls, the thermoplastic polymer film and the adherend are overlapped, and from both sides thereof. There has been proposed a method in which a film and an adherend are firmly bonded in a short time by pressing in a state of being sandwiched between covering materials. However, this method has drawbacks such that the protective material is in direct contact with the heating and pressing surface, so that the protective material is rapidly deteriorated, and the number of reuses of the protective material is reduced, resulting in an increase in manufacturing cost. As in the case of Patent Document 2, the heat transfer effect for transferring the heat of the pressure roll to the laminated body is hindered, and there is a possibility that the adhesive force between the metal foil and the liquid crystal polymer film is lowered or the adhesive force is varied. is there.

  Furthermore, in Patent Document 4, as a method for producing a metal-clad laminate with high productivity on an industrial scale, lamination is performed in a mode in which a single-sided metal-clad laminate is laminated on both sides of a separation film at the time of lamination, A method for peeling a single-sided metal-clad laminate from a spacing film is shown. This method relates to a method for producing a single-sided metal-clad laminate, and an insulating film is in contact with the separation film. Therefore, in patent document 4, in order to improve the peelability with an insulating film, the surface roughness of a separation film is prescribed | regulated. Therefore, this technique does not teach the case of producing a double-sided metal-clad laminate in which the spacing film is in contact with the metal foil, and this is not applicable.

JP 2008-272958 A WO 2004/108397 JP 2001-88219 A WO2011 / 093427 publication

  The present invention provides a double-sided metal-clad laminate that is excellent in industrial productivity with excellent interlaminar adhesion between an insulating film and a metal foil, without variation in adhesive strength, and suppressing occurrence of appearance defects such as wrinkles. It is an object to provide a method that can be manufactured.

  As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have determined that the combination of the insulating film and the metal foil is symmetric about the distance film so as to be symmetrical up and down. By stacking and thermocompression bonding with pressure rolls, there is no risk of film fusing to the pressure rolls, and the pressure between the pressure rolls is more evenly transmitted. In addition, it has been found that two sets of double-sided metal-clad laminates with stable quality can be obtained at one time by separating or peeling from the separation film, and the like. Was completed.

That is, the present invention is a method for producing a double-sided metal-clad laminate in which metal foils (B, B ′) are bonded to both surfaces of an insulating film (A) having an adhesive surface made of a thermoplastic resin on at least the surface. Then, using the separation film (C) having a heat capacity in the range of 50 to 150 J / m ² , (r ₁ ) / (B) / (A) between the pair of pressure rolls (r ₁ , r ₂ ) / (B ′) / (C) / (B ′) / (A) / (B) / (r ₂ ) in order of insulating film (A), metal foil (B, B ′), And the two-sided metal-clad laminate obtained by separating and peeling the double-sided metal-clad laminate from the separation film (C) and then thermocompression bonding the separation film (C). It is a manufacturing method of a body.

  Further, in the present invention, the pair of pressure rolls is composed of a metal surface roll having a surface temperature adjusting function, the surface roughness Rz of the roll surface is Rzr, and the surface of the metal foil (B) in contact with the roll surface When the surface roughness Rz is RzB and the surface roughness Rz of the separation film (C) in contact with the surface of the metal foil (B) is RzC, both Rzr-RzB and RzC-RzB are ± 0.8 μm or less. It is preferable to do so.

  In the present invention, the insulating film (A) is preferably composed of a thermoplastic liquid crystal polymer film or a heat resistant resin film provided with a thermoplastic resin layer on both sides of the heat resistant resin layer. In the present invention, preferably, the separation film (C) may be selected from an aluminum foil, a heat-resistant resin film, or a composite film having a metal foil on the front and back surfaces of the resin film. In the invention, the metal foil (B) is preferably a copper foil having a thickness of 1 to 100 μm.

  According to the present invention, a high-quality double-sided metal-clad laminate excellent in interlayer adhesion between an insulating film and a metal foil is produced industrially with high productivity, eliminating wrinkles and variations in adhesive strength. Will be able to. That is, the production method of the present invention can significantly increase the industrial production efficiency as compared with the conventional method, and can produce a high-quality double-sided metal-clad laminate at a lower cost. And since the double-sided metal-clad laminate obtained by the present invention is high quality and excellent in reliability, for example, it is suitably used as a circuit board for which fine pattern formation is required, or as a substrate material for a multilayer circuit board. be able to.

FIG. 1 is a schematic side view illustrating a method for producing a double-sided metal-clad laminate according to an embodiment of the present invention. FIG. 2 is a schematic plan view illustrating the test piece used for evaluating the adhesion between the insulating film and the metal foil.

Hereinafter, the present invention will be described in detail.
In the present invention, between the pair of pressure rolls (r ₁ , r ₂ ), a metal foil (B) / insulating film (A
) / Metal foil (B ′) / separating film (C) / metal foil (B ′) / insulating film (A) / metal foil (B) in the order of thermocompression bonding and separating film (C ) To produce two double-sided metal-clad laminates in which metal foils (B, B ′) are bonded to both sides of the insulating film (A) at the same time.

  Here, the insulating film (A) used in the present invention has an adhesive surface made of a thermoplastic resin, and the metal foil (B, B ′) can be bonded to the adhesive surface by thermocompression bonding. There is no particular limitation as long as it includes i) a thermoplastic resin film, and ii) a heat resistant resin film in which a thermoplastic resin layer is provided on both sides of the heat resistant resin layer. Moreover, what laminated | stacked these 1 type (s) or 2 or more types into multiple layers can also be used.

  Among these, as i) insulating film (A) made of a thermoplastic resin film, for example, polyethylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, acrylonitrile / styrene copolymer resin, thermoplastic polyimide resin, liquid crystal polymer, etc. Among these, from the viewpoint of processability, electrical characteristics, heat resistance, and the like, a liquid crystal polymer or a thermoplastic polyimide resin is preferably used.

Examples of the liquid crystal polymer include known thermotropic liquid crystal polyesters and thermotropic liquid crystal polyester amides derived from the compounds classified into the following (1) to (4) and derivatives thereof.
(1) Aromatic or aliphatic dihydroxy compounds (2) Aromatic or aliphatic dicarboxylic acids (3) Aromatic hydroxycarboxylic acids (4) Aromatic diamines, aromatic hydroxyamines or aromatic aminocarboxylic acids

Among the liquid crystal polymers obtained from these raw material compounds, aromatic liquid crystal polymers that do not contain an aliphatic chain in the molecule are preferred. As a typical example of such a liquid crystal polymer, a copolymer having a structural unit represented by the following formula obtained using 6-hydroxy-2-naphthoic acid and p-hydroxybenzoic acid as raw materials can be given. Incidentally, m ₂ and n ₂ in the formula is a positive number indicating the presence molar ratio of the respective structural units.

  In consideration of heat resistance and workability in thermocompression bonding, the liquid crystal polymer is preferably in the range of 200 to 400 ° C, more preferably in the range of 250 to 350 ° C, and the transition temperature to an optically anisotropic melt phase. It is good to have. The liquid crystal polymer may be blended with, for example, a lubricant, an antioxidant, a filler, and the like, as long as the characteristics are not impaired.

  Examples of the method for forming a liquid crystal polymer into a film include a T-die method, a laminate stretching method, and an inflation method. In the inflation method and the laminate stretching method, stress is applied not only in the mechanical axis direction of the film (MD direction) but also in the direction perpendicular to this (TD direction), so the balance of mechanical properties in the MD and TD directions. An excellent film can be obtained. In addition, a commercial item can also be used for a liquid crystal polymer film, for example, Kuraray Co., Ltd. Vecstar (registered trademark), Japan Gore-Tex Co., Ltd. BIAC, STABIAX (both are registered trademarks), etc. can be used. .

  The thermoplastic polyimide resin can be formed by imidizing (curing) the precursor polyamic acid, and the polyamic acid reacts with a known diamine and acid anhydride in the presence of a solvent. Can be manufactured.

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

  Examples of the diamine used include 4,4′-diaminodiphenyl ether, 2′-methoxy-4,4′-diaminobenzanilide, 1,4-bis (4-aminophenoxy) benzene, and 1,3-bis (4 -Aminophenoxy) benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4 Examples include '-diaminobiphenyl and 4,4'-diaminobenzanilide. Examples of the acid anhydride include pyromellitic anhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, and 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride. Products, 4,4′-oxydiphthalic anhydride and the like. Each of the diamine and the acid anhydride may be used alone or in combination of two or more. In addition, a polyimide resin is not limited to what is obtained from the said diamine and an acid anhydride.

  When a thermoplastic polyimide resin film is used as the insulating film (A), the film can be formed into a film from a polyamic acid which is a precursor of the polyimide resin by a known method such as a tenter method or a cast method. In the tenter method, which is one of the typical methods, a polyamic acid solution is cast on a rotating drum, peeled off from the rotating drum in the form of a polyamic acid gel film, and heated and cured (imidized) in a tenter furnace. This is a method of forming a polyimide film. The casting method is a method in which a polyamide acid solution is applied to an arbitrary supporting substrate, dried, and then heat-treated and cured (imidized) to form a polyimide film. The imidization can be performed, for example, by heating for a time within a range of 1 to 60 minutes under a temperature condition within a range of 80 to 400 ° C. In addition, a lubricant, an antioxidant, a filler, etc. can be mix | blended with a polyimide resin in the range which does not impair the characteristic, for example.

  As the insulating film (A), ii) when a heat resistant resin film provided with a thermoplastic resin layer on both sides of the heat resistant resin layer is used, the heat deformation temperature of the heat resistant resin layer is higher than that of the thermoplastic resin layer. However, a non-thermoplastic polyimide resin film is particularly preferable. The non-thermoplastic polyimide resin can be produced by reacting a known diamine and an acid anhydride in the presence of a solvent in the same manner as the thermoplastic polyimide. It can be a polyimide resin. As this non-thermoplastic polyimide resin film, for example, Kapton EN, Kapton H, Kapton V (all trade names) manufactured by Toray DuPont Co., Ltd., Apical NPI (trade names manufactured by Kaneka Chemical Co., Ltd.) ), Upilex S (trade name) manufactured by Ube Industries, Ltd., and the like. The non-thermoplastic polyimide resin film preferably has a glass transition temperature of 300 ° C. or higher, and more preferably does not deform at the thermocompression bonding temperature by a roll.

  Further, the thermoplastic resin layers provided on both surfaces of the heat resistant resin layer may be formed from a resin having a glass transition temperature at least below the heating temperature in thermocompression bonding, and the type of resin is particularly limited. However, for example, thermoplastic polyimide resin, thermoplastic liquid crystal polymer, polyether ether ketone, polyethylene naphthalate and the like can be exemplified. The thermoplastic resin layer may be formed by bonding a thermoplastic resin film to a film material composed of a heat resistant resin layer, and is formed by applying a polyimide precursor on the film material by a casting method or the like. You may make it do.

  The thickness of the insulating film (A) is preferably 5 to 200 μm, more preferably 10 to 100 μm. If the insulating film (A) is too thin, the rigidity is lowered, and problems such as wrinkles and tearing may occur in the manufacturing process of the metal-clad laminate and the processing process of the wiring board using the obtained laminate. On the other hand, if the thickness is too thick, the insulating film lacks flexibility, making it difficult to transport by roll-to-roll in the manufacturing process of metal-clad laminates, and circuit-processed wiring boards are also difficult to fit in a narrow housing. May cause problems.

  The material of the metal foil (B, B ′) used in the present invention is not particularly limited, and examples thereof include gold, silver, copper, stainless steel, nickel, and aluminum. Of these, copper foil and stainless steel foil are preferred from the viewpoints of conductivity, ease of handling, price, and the like. Of these, any copper foil produced by a rolling method or an electrolytic method can be used. In addition, for the purpose of improving the adhesive strength with the insulating film, in addition to physical surface treatment such as roughening treatment, the metal foil is subjected to chemical surface treatment such as acid cleaning, UV treatment and plasma treatment in advance. Also good.

  The thickness of the metal foil (B, B ′) is preferably 1 to 100 μm, more preferably 5 to 70 μm, and still more preferably 8 to 20 μm. It is desirable to reduce the thickness of the metal foil because it is easy to form a fine pattern in circuit processing. However, if it is too thin, the metal foil tends to wrinkle in the manufacturing process of the metal-clad laminate, and the circuit processing is performed. In the wiring board, the wiring is easily broken, and the reliability as the wiring board may be reduced. On the other hand, when the thickness is too thick, when the circuit is formed by etching the metal foil, the side surface of the circuit is likely to be tapered, which is disadvantageous for fine pattern formation.

The separation film (C) used in the present invention needs to have a heat capacity in the range of 50 to 150 J / m ² . If the heat capacity is less than 50 J / m ² , the variation in the adhesion between the copper foil and the insulating layer of the double-sided copper clad laminate to be produced becomes large, while if the heat capacity exceeds 150 J / m ² , the separation film ( Not only does the adhesiveness between the copper foil on the side in contact with C) and the insulating layer not fully develop, but also the adhesiveness tends to vary.

    Further, the separation film (C) needs to have heat resistance that can withstand the thermocompression bonding temperature, and needs to be easily separated or peelable from the metal foil (B ′) after thermocompression bonding. From the latter viewpoint, the front and back surfaces of the separation film (C) are preferably those having a surface roughness (Rz) of 2.0 μm or less, preferably 0.5 to 1.5 μm. As such a separation film (C), a heat-resistant resin film such as a non-thermoplastic polyimide film or a polyamide film, or a metal foil such as an aluminum foil or a stainless steel foil is preferably used. Moreover, the composite film which has metal foil on the front and back of the resin film can also be used.

  About the separating film (C), you may make it mold release process the single side | surface or both surfaces of a separating film (C) in order to improve peelability with metal foil (B ') after thermocompression bonding. As a specific method of the release treatment, for example, a method of providing a heat-resistant release resin film such as a silicone resin or a fluorine resin on the separation film (C) can be mentioned.

  The thickness of the separation film (C) is preferably 10 to 300 μm, more preferably 20 to 150 μm, and still more preferably 30 to 100 μm. If the separation film (C) is too thin, the pressure buffering effect that uniformly disperses the pressure during thermocompression bonding is reduced, and the interlayer adhesion between the insulating film (A) and the metal foil (B) of the finished metal-clad laminate is reduced. Variation may occur. On the other hand, if it is too thick, there is a risk that the roll-to-roll method may be hindered or the workability when peeling from the metal-clad laminate after thermocompression bonding may be deteriorated.

Between a pair of pressure rolls (r ₁ , r ₂ ), (r ₁ ) / (B) / (A) / (B ′) / (C) / (B ′) / (A) / (B) / In order to thermocompression-bond the insulating film (A), the metal foils (B, B ′), and the separation film (C) stacked in the order of (r ₂ ), a pair of pressure rolls equipped with a heating mechanism is used. A known heating and pressurizing apparatus can be used. At that time, for the insulating film (A), the metal foil (B, B ′), and the separation film (C), long materials wound in a roll shape are used in combination with a heating and pressing device. The continuous production of double-sided metal-clad laminates becomes possible. Further, there is no particular limitation on the pressure roll temperature and the pressure condition of the pressure roll, but the thermoplastic resin of the insulating film (A) is favorably bonded to the metal layer (B, B ′) by deformation or the like. Therefore, it is preferable to carry out at a temperature slightly lower than the Tg or melting point of the thermoplastic resin. For example, when a liquid crystal polymer film is used for the insulating film (A), a temperature range that is 5 to 100 ° C. lower than the melting point is preferable, and a temperature range that is 20 to 80 ° C. lower than the melting point is more preferable. In addition, the pressurizing pressure is preferably in the range of 20 to 200 kN / m.

In the present invention, the surface roughness Rz on the surface of the pressure roll (r ₁ , r ₂ ) is Rzr, and the surface roughness of the surface of the metal foil (B) in contact with the surface of the pressure roll (r ₁ , r ₂ ). When Rz is RzB and the surface roughness Rz of the separating film (C) in contact with the surface of the metal foil (B) is RzC, the value of Rzr-RzB is preferably ± 0.8 μm or less, Rzr-RzB and RzC-RzB is more preferably ± 0.8 μm or less, and this value is particularly preferably in the range of ± 0.01 to 0.5 μm. When these differences are larger than the above values, differences in characteristics such as adhesion of mass-produced double-sided copper-clad laminates are likely to occur.

In the present invention, the insulating film (A) and the metal foils (B, B ′) arranged on both the upper and lower sides of the spacing film (C) are symmetrical positions about the spacing film (C). Since the relationship is established, thermocompression bonding can be performed with the temperature of the pair of pressure rolls (r ₁ , r ₂ ) being the same, and unnecessary heat loss between the rolls can be prevented. Moreover, since all of the pressure rolls are in contact with the metal foil (B), the heat conduction from the pressure roll is not easily inhibited. And after thermocompression bonding, as will be described in the following examples, the metal foil (B ′) and the separation film (C) can be separated or peeled off very easily, eliminating variations in adhesive strength, Occurrence can be prevented, and a high-quality double-sided metal-clad laminate with good adhesion can be obtained with high productivity.

  EXAMPLES Next, although an Example demonstrates this invention more concretely, this invention is not restrict | limited to these content. In the examples of the present invention to be described later, unless otherwise specified, processing conditions and measurement (evaluation) conditions are as follows.

[Measurement of surface roughness]
In accordance with JIS B 0601, using a stylus type surface roughness tester (TENCOR, TENCOR P-10), Rz (10-point average) under the conditions of a load of 100 μN, a scanning speed of 20 μm / second, and a measurement distance of 800 μm. (Roughness) was measured.

[Adhesion evaluation of metal-clad laminates]
The obtained double-sided copper clad laminate was cut into a length of 150 mm in the laminating direction (MD direction), and the copper foil was etched by a subtractive method using a commercially available etching solution (Adeka Kermica FE-210, manufactured by ADEKA Co., Ltd.). Then, a linear conductor pattern 7 having a width of 1 mm and a length of 100 mm was formed along the laminating direction (FIG. 2). At this time, the linear conductor pattern 7 is formed at three positions, a center position in the width direction (length direction of the pressure roll) of the double-sided metal-clad laminate, and a position 10 mm away from the center in the left and right directions in the width direction, An adhesion test piece was obtained. A test piece was formed on each of the copper foil surface (B) in contact with the laminate roll and the copper foil surface (B ′) in contact with the separating film, and the adhesion was evaluated. About the three linear conductor patterns of this adhesion test piece, the intensity | strength which peels from an insulating film (A) was measured according to JISC 6471 8.1 method B (180 degree direction peeling). Then, “adhesiveness” was evaluated in two stages, in which the case where the average value of the three peel strengths was 0.8 kN / m or more was good and the case where it was less than 0.8 kN / m was bad. Further, regarding the variation in adhesion, the difference between the maximum value and the minimum value of the three peel strengths is good when it is less than 0.3 kN / m, and it is poor when 0.3 kN / m or more is bad. The “adhesion variation” was evaluated.

Example 1
As the insulating film (A), a long film in which a liquid crystal polymer film 2 (melting point: 320 ° C.) having a thickness of 50 μm and a width of 30 mm is wound in a roll shape is prepared, and the metal foil (B, B ′) has a thickness A commercially available electrolytic copper foil 1 and 1 ′ having a width of 12 μm and a width of 40 mm (surface roughness Rz: insulating film laminated surface 1.6 μm, exposed surface 1.4 μm) is prepared as a long copper foil wound in a roll shape, As the spacing film (C), a commercially available heat-resistant polyimide film 3 having a thickness of 50 μm and a width of 40 mm, which is non-thermoplastic (Tg: 340 ° C., both surface roughness Rz: 0.9 μm, heat capacity 79.8 J / m ² ) Was prepared as a long heat-resistant polyimide film wound in a roll shape. As shown in FIG. 1, these are set on an insulating film feeding roll A, metal foil feeding rolls B and B ′, and a separation film feeding roll C, respectively, and between a pair of pressure rolls 4 (r ₁ , r ₂ ). , And supply in an order of "electrolytic copper foil 1 / liquid crystal polymer film 2 / electrolytic copper foil 1 '/ heat resistant polyimide film 3 / electrolytic copper foil 1' / liquid crystal polymer film 2 / electrolytic copper foil 1", It cools naturally after thermocompression bonding, the heat resistant polyimide film 3 and the electrolytic copper foil 1 ′ are delaminated by the peeling roll 6, the heat resistant polyimide film 3 is recovered by the separation film winding roll C ′, and the liquid crystal polymer film 2 And the double-sided copper clad laminate 5 in which the electrolytic copper foils 1 and 1 ′ are bonded to each other are collected by the product take-up rolls x installed at two locations.

  Electrolytic copper foils 1, 1 ′, liquid crystal polymer film 2 and heat-resistant polyimide film 3 are all moved at a speed of 0.7 m / min, and both are pressed between pressure rolls 4 having a surface temperature of 280 ° C. Thermocompression bonding is performed at a pressure between rolls of 40 kN / m. After thermocompression bonding, the laminate is cooled by natural cooling, and the heat-resistant polyimide film 3 is collected by the separation film winding roll C ′, and two product winding rolls are collected. In x, the double-sided copper clad laminate 5 according to Example 1 was collected. The pressure roll 4 of the apparatus used in Example 1 is a carbon steel metal roll having a surface roughness Rz of 1.6 μm having a surface temperature adjusting function inside a roll having a length of 130 mm and a roll diameter of 150 mm. Using.

  In Example 1 described above, delamination of the heat-resistant polyimide film 3 as the separation film and the electrolytic copper foil 1 ′ after thermocompression bonding was performed very smoothly without any trouble, and the collected double-sided copper-clad laminate 5 was visually observed. As a result of confirmation, no tears, wrinkles, or rough surfaces were observed. In addition, from one side of the double-sided copper clad laminate 5 collected at two locations, an adhesion test piece is prepared as described above, and an adhesion evaluation between the liquid crystal polymer film 2 and the electrolytic copper foil 1 and 1 ′ is performed. As a result, the “adhesion” evaluated by the average value of the peel strengths obtained with the three linear conductor patterns was 0.83 kN / m and 1.02 kN / m, respectively, which were favorable. Furthermore, the “adhesion variation” obtained from the difference between the maximum value and the minimum value of the three peel strengths is 0.27 kN / m and 0.08 kN / m, respectively. It was confirmed that the copper foils 1 and 1 ′ were uniformly bonded in the plane. The results are shown in Table 1.

(Example 2)
As the spacing film (C), a commercially available heat-resistant polyimide film 3 (Tg: 340 ° C., surface roughness Rz: 0.9 μm, heat capacity 119.6 J / m ² ) on both sides is used. A double-sided copper-clad laminate according to Example 2 was obtained in the same manner as Example 1 except that.

  In Example 2, delamination between the electrolytic copper foil 1 ′ and the heat-resistant polyimide film 3 after thermocompression bonding was performed very smoothly without any defects. In addition, the evaluation using the adhesion test piece shows that “adhesion” is good, “adhesion variation” is also good, and the liquid crystal polymer film 2 and the electrolytic copper foils 1 and 1 ′ are uniform in the plane. It was confirmed that it was adhered to. The results are shown in Table 1.

(Example 3)
Double-sided copper-clad laminate (Espanex M series (MB12-25-12REQ) manufactured by Nippon Steel Chemical Co., Ltd., surface roughness Rz: 0.85 μm, heat capacity 122.8 J / m ² ) A double-sided copper-clad laminate according to Example 3 was obtained in the same manner as Example 1 except that was used. This double-sided copper-clad laminate has a polyimide resin with a thickness of 25 μm as an insulating layer at the center, and a copper foil with a thickness of 12 μm is provided on both sides, and the surface roughness (Rz of the exposed surface of the copper foil) ) Is 0.85 μm.

  Also in the manufacture of Example 3, the delamination of the electrolytic copper foil 1 ′ after thermocompression bonding and the double-sided copper-clad laminate 3 which is a separation film was performed very smoothly without any defects. Further, in the evaluation using the adhesion test piece, “adhesion” is good, “adhesion variation” is also good, and the obtained double-sided copper clad laminate 5 is uniformly bonded in the surface. It was confirmed. The results are shown in Table 1.

Example 4
The same procedure as in Example 1 was performed except that an aluminum foil having a thickness of 25 μm (surface roughness Rz: 1.2 μm, heat capacity 60.5 J / m ² ) was used as the separation film (C). A double-sided copper clad laminate according to Example 4 was obtained.

  Also in the manufacture of Example 4, the delamination of the electrolytic copper foil 1 ′ after thermocompression bonding and the aluminum foil 3 as the separation film was performed very smoothly without any defects. Further, in the evaluation using the adhesion test piece, “adhesion” is good, “adhesion variation” is also good, and the obtained double-sided copper clad laminate 5 is uniformly bonded in the surface. It was confirmed. The results are shown in Table 1.

(Example 5)
The same procedure as in Example 1 was performed except that an aluminum foil having a thickness of 50 μm (surface roughness Rz: 1.2 μm, heat capacity 121.1 J / m ² ) was used as the separation film (C). A double-sided copper-clad laminate according to Example 5 was obtained.

  Also in the manufacture of Example 5, delamination of the electrolytic copper foil 1 ′ after thermocompression bonding and the aluminum foil 3 as the separation film was performed smoothly without any problem. Further, in the evaluation using the adhesion test piece, “adhesion” is good, “adhesion variation” is also good, and the obtained double-sided copper clad laminate 5 is uniformly bonded in the surface. It was confirmed. The results are shown in Table 1.

(Comparative Example 1)
As the spacing film (C), a commercially available heat-resistant polyimide film 3 (Tg: 340 ° C., surface roughness Rz: 0.9 μm, heat capacity 39.9 J / m ² ) on both sides is used. A double-sided copper-clad laminate according to Comparative Example 1 was obtained in the same manner as Example 1 except that.

  Also in the manufacture of Comparative Example 1, delamination between the heat-bonded electrolytic copper foil 1 ′ and the heat-resistant polyimide film 3, which is a separation film, was performed very smoothly without any defects. However, in the evaluation with the adhesion test piece, the “adhesion” was good, but the “variation in adhesion” was 0.32 kN / m, and compared with the results of the examples, the double-sided copper-clad laminate The in-plane adhesion was found to be non-uniform. The results are shown in Table 1.

(Comparative Example 2)
As the separation film (C), a commercially available heat-resistant polyimide film 3 (Tg: 340 ° C., surface roughness Rz: 0.9 μm, heat capacity 159.5 J / m ² ) on both sides is used. A double-sided copper-clad laminate according to Comparative Example 2 was obtained in the same manner as Example 1 except that.

   Also in the manufacture of Comparative Example 2, delamination between the heat-bonded electrolytic copper foil 1 ′ and the heat-resistant polyimide film 3, which is a separation film, was performed extremely smoothly without any defects. However, in the evaluation with the adhesion test piece, “adhesion” was good, but “adhesion variation” was 0.40 kN / m, which is a double-sided copper clad laminate compared with the results of the examples. The in-plane adhesion was found to be non-uniform. The results are shown in Table 1.

(Comparative Example 3)
As the spacing film (C), a commercially available heat-resistant polyimide film 3 (Tg: 340 ° C., surface roughness Rz: 0.9 μm, heat capacity 199.4 J / m ² ) on both sides is used. A double-sided copper-clad laminate according to Comparative Example 3 was obtained in the same manner as Example 1 except that.

   Also in the manufacture of Comparative Example 3, delamination between the electro-deposited copper foil 1 ′ after thermocompression bonding and the heat-resistant polyimide film 3 as a separation film was performed very smoothly without any defects. However, in the evaluation using the adhesion test piece, the “adhesion” between the electrolytic copper foil 1 ′ on the separation film side and the liquid crystal polymer film 2 is 0.51 kN / m, and the adhesion is lower than the results of the examples. I understood that. The results are shown in Table 1.

(Comparative Example 4)
Double-sided copper-clad laminate (Espanex M series (MB12-50-12REQ) manufactured by Nippon Steel Chemical Co., Ltd., surface roughness Rz: 0.85 μm, heat capacity 162.8 J / m ² ) A double-sided copper clad laminate according to Comparative Example 4 was obtained in the same manner as Example 1 except that was used.

   Also in the manufacture of Comparative Example 4, the delamination of the electrolytic copper foil 1 ′ after thermocompression bonding and the double-sided copper-clad laminate 3 as a separation film was performed smoothly without any problems. However, in the evaluation using the adhesion test piece, the “adhesion” between the electrolytic copper foil 1 ′ on the side of the separation film and the liquid crystal polymer film 2 is 0.55 kN / m, and the adhesion is lower than the results of the examples. I understood that. The results are shown in Table 1.

(Comparative Example 5)
A double-sided copper clad laminate according to Comparative Example 5 was obtained in the same manner as in Example 1 except that a 50 μm-thick stainless steel foil (heat capacity 196.7 J / m ² ) was used as the spacing film (C).

   Also in the manufacture of Comparative Example 5, delamination between the electrolytic copper foil 1 ′ after thermocompression bonding and the stainless steel foil 3 as the separation film was performed very smoothly without any defects. However, in the evaluation using the adhesion test piece, the “adhesion” between the electrolytic copper foil 1 ′ on the side of the separation film and the liquid crystal polymer film 2 is 0.71 kN / m, and the adhesion is lower than the results of the examples. I understood that. The results are shown in Table 1.

  From the above results, according to the manufacturing method according to the present invention, a high-quality double-sided metal-clad laminate excellent in interlayer adhesion between the insulating film and the metal foil without wrinkles or variations in adhesive strength is obtained. It was found that it can be produced industrially with high productivity. In addition, this invention is not restrict | limited to the said embodiment, A various deformation | transformation is possible.

1, 1 ': Electrolytic copper foil (metal foil (B, B'))
2: Liquid crystal polymer film (insulating film (A))
3: Heat-resistant polyimide film (spaced film (C))
4: Pressure roll 5: Double-sided copper clad laminate 6: Peeling roll 7: Linear conductor pattern

Claims (5)

A method for producing a double-sided metal-clad laminate in which metal foils (B, B ′) are adhered to both surfaces of an insulating film (A) having an adhesive surface made of a thermoplastic resin on at least a surface, wherein the heat capacity is 50 (R ₁ ) / (B) / (A) / (B ′) / between the pair of pressure rolls (r ₁ , r ₂ ) using the separation film (C) in the range of ˜150 J / m ² (C) / (B ′) / (A) / (B) / (r ₂ ) In order of the insulating film (A), the metal foil (B, B ′), and the separation film (C) Are laminated and thermocompression bonded, and then the double-sided metal-clad laminate is separated or peeled from the separating film (C) to obtain two double-sided metal-clad laminates.   A pair of pressure rolls consists of a roll having a metal surface having a surface temperature adjustment function, the surface roughness Rz of the roll surface is Rzr, and the surface roughness Rz of the surface of the metal foil (B) in contact with the roll surface is RzB. The both surfaces according to claim 1, wherein Rzr-RzB and RzC-RzB are both ± 0.8 µm or less, where RzC is the surface roughness Rz of the separation film (C) in contact with the surface of the metal foil (B). A method for producing a metal-clad laminate.   The method for producing a double-sided metal-clad laminate according to claim 1, wherein the insulating film (A) comprises a thermoplastic liquid crystal polymer film or a heat-resistant resin film having a thermoplastic resin layer on both sides of the heat-resistant resin layer.   The production of the double-sided metal-clad laminate according to claim 1 or 2, wherein the spacing film (C) is selected from an aluminum foil, a heat-resistant resin film, or a composite film having a metal foil on the front and back surfaces of the resin film. Method.   The method for producing a double-sided metal-clad laminate according to any one of claims 1 to 4, wherein the metal foil (B) is a copper foil having a thickness of 1 to 100 µm.

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