JP2009262531A - Laminate manufactuiring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate manufacturing method capable executing stable production at a high yield by avoiding defects in appearance due to transfer of a step at the end of a laminate occurring in a process of manufacturing a metal clad laminated plate for circuit boards using a resin film as the insulation layer and defects in appearance occurring in heat treatment of the laminate and associated with fusion of a molten film with a metal foil of an adjacent layer. <P>SOLUTION: The method for manufacturing a laminate having metal foil on one or both sides of a resin film includes the step of heat-treatment of the wound laminate roll after the film and metal foil are laminated and wound around a winding core in the form of a roll, with at least the winding starting end of the laminate in the roll kept free from the contact pressure from the surface of the outer laminate portion and the winding core surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing a laminate of a resin film and a metal foil. More specifically, the present invention relates to a resin film, particularly a film made of a liquid crystal polymer capable of forming an optically anisotropic molten phase (hereinafter referred to as a film). And a liquid crystal polymer film) and a method for producing a laminate formed by superimposing a metal foil.

  In general, a resin film, particularly a liquid crystal polymer film, is known as a material excellent in high heat resistance, hygroscopic dimensional stability, high frequency characteristics, and the like. Paying attention to such characteristics of the liquid crystal polymer film, it has been studied to use it as an insulating material for an electronic circuit board. When used for an electronic circuit board, a laminate of a liquid crystal polymer film and a metal foil represented by copper foil is suitable as a laminate for a wiring board.

  Conventionally, a hot press apparatus has been used as a technique for producing a laminate composed of a liquid crystal polymer film and a metal foil. As a typical example, there is a method in which a liquid crystal polymer film cut to a predetermined size and a metal foil are placed between upper and lower hot plates of a hot press apparatus and heat-pressed in a vacuum state. However, since this method is a batch method, there is a problem that it is not possible to produce a laminate having a uniform quality in terms of peel strength and the production speed per laminate is slow, resulting in a high cost. Has the disadvantage of becoming.

  Therefore, a method for continuously producing a laminate has been proposed in order to increase the production speed at a low cost (Patent Document 1). This is because the liquid crystal polymer film and the metal foil are overlapped, and the film and the metal foil are placed between the pressure rolls at a temperature in the range from 80 ° C. below the melting point of the liquid crystal polymer to 5 ° C. below the melting point. And thermocompression bonded. Further, the film and the film are passed by passing between heating and pressing rolls including at least one roll having a surface temperature in a range from a temperature lower than the melting point of the liquid crystal polymer by 80 ° C. to a temperature lower than the melting point by 5 ° C. The metal foil is to be crimped.

  Moreover, in order to provide a metal-clad laminate for circuit boards excellent in dimensional stability with high productivity, the first step for performing thermocompression bonding of the above-mentioned liquid crystal polymer film and metal foil was obtained in the first step. The manufacturing method provided with the 2nd process of heat-processing a laminated body above the melting | fusing point of a liquid crystal polymer film is proposed (patent document 2).

  Furthermore, after finishing the first step and the second step, heat treatment and cooling solidification are repeated a plurality of times as the third step in the subsequent stage, and the heat treatment temperature is changed in accordance with the change in the melting point of the liquid crystal polymer at each heat treatment. Has been proposed (Patent Document 3), and it is said that a laminate having excellent heat resistance and wear resistance can be obtained by such heat treatment. In this third step, the heat treatment takes several hours, so the laminated body wound up in a roll shape is heat-treated in a batch type. In this case, the step at the winding end of the laminated body attached to the core is heat treated. There was a problem of transferring to the outer part of the roll and deteriorating the appearance of the laminate at that part. Further, in the laminate having the metal foil only on one side of the liquid crystal polymer film, the film melted during the heat treatment is fused to the metal foil of the adjacent layer, and the surface shape of the metal foil is There was a problem of transferring to the surface.

  As a method of relieving the transfer mark of the step as described above, a winding core is proposed in which convex stepped portions having a height of 1 to 10 times the thickness of the substrate to be wound are provided on the outer periphery of both ends of the winding core. (Patent Document 4). Further, as a similar method, a winding in which a tape that is 1% or less of the width of the base material wound around the outer periphery of both ends of the core and within ± 20% of the base material thickness is placed so as to overlap the base material. A method using a lead has been proposed (Patent Document 5). However, this method cannot sufficiently improve the yield because it is impossible to prevent the generation of a transfer mark at the contact portion between the base material and the tape. Moreover, in the laminated body which has metal foil only on the one side of a liquid crystal polymer film, since it cannot become a technique which prevents a melt | fusion, development of another method is calculated | required.

JP-A-5-42603 JP 2000-343610 A JP 2000-44797 A Japanese Patent Laid-Open No. 9-58935 JP 2002-308483 A

  In view of such circumstances, the present invention is a poor appearance due to the transfer of the step of the laminate winding start end generated in the manufacturing process of a metal-clad laminate for circuit boards using a resin film, particularly a liquid crystal polymer film as an insulating layer, Laminate that can be stably manufactured at a high yield by preventing the appearance defect associated with fusion between the melted film and the metal foil of the adjacent layer generated during the heat treatment of the laminate having the metal foil only on one side of the film It aims at providing the manufacturing method of.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by performing a heating step for increasing heat resistance under specific conditions. It came to be completed.
That is, the present invention is a method for producing a laminate having a metal foil on one side or both sides of a resin film, for example, a liquid crystal polymer film, and after laminating the film and the metal foil and winding it in a roll on a core ( For example, after transporting the transportable laminate formed by thermocompression bonding of the film and the metal foil in the first step and transporting it in the second step, after winding this around a roll core), When the laminate roll is heat-treated by a heating furnace or a heating device in the third step, at least winding of the laminate in the wound laminate roll (roll wound under a predetermined tension by a winding device or the like) In this manufacturing method, the take-off end is subjected to a heat treatment in a state where it does not receive contact pressure from the outer surface of the laminated body and the core surface.
Here, the state where the contact pressure is not received is a state where the contact pressure is not substantially generated at the contact portion at the time of heating and the transfer pressure is not generated at the winding start end step, or the state where the contact pressure is not received by no contact at all. Say.
Further, the state where the contact pressure is not received is performed by unwinding and unfolding the roll in a vertically placed state (a state where the longitudinal direction of the core is perpendicular to the ground), and winding the roll. Then, it can carry out by changing the outer diameter of this core.
Further, particularly in a laminate having a metal foil only on one side of the liquid crystal polymer film, it is possible to heat-treat the take-up laminates at a distance of 5 μm or more even in a laminate other than the winding start end. preferable.
According to the above means, the following operation can be obtained.

  According to the manufacturing method of the present invention, it is possible to prevent the appearance defect due to the transfer of the step of the laminate winding start end. Furthermore, in a laminate having a metal foil only on one side of the film, transfer of the surface shape of the metal foil to the film surface can be prevented. Since the laminate produced here is excellent, without impairing the high heat resistance, hygroscopic dimensional stability, high-frequency characteristics, etc. specific to the liquid crystal polymer, and without impairing the adhesion between the liquid crystal polymer film and the metal foil, For example, it is useful as a laminate used for a circuit board typified by a flexible circuit board.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 7 show embodiments of the present invention, and the method for producing a laminate of the present invention is not limited to the following embodiments, and various modifications are made within the scope not departing from the gist of the present invention. Of course, can be added.

This invention is a method of manufacturing the laminated body 5 which has the metal foil 4, 4 'on the one side or both sides of the liquid crystal polymer film 3, as shown in FIGS. After laminating the liquid crystal polymer film 3 and the metal foil 4 and winding the wound core around the winding core with a predetermined winding force, when the winding roll 8 is heat-treated, at least start winding of the laminate in the roll The end is heat-treated with no contact pressure from the outer laminate surface and the core surface.
Further, heat treatment is performed so that the laminated body other than the winding start end is not subjected to contact pressure, and the winding laminated bodies in the roll are separated from each other by 5 μm or more.
The winding roll of the present invention is a second step shown in FIG. 2 in which the transportable laminate 5 formed by thermocompression bonding of the liquid crystal polymer film 3 and the metal foils 4 and 4 ′ in the first step shown in FIG. The laminate roll 8 wound in the form of a roll on a metal core after being heat-treated as necessary while being conveyed is used.

  More specifically, the embodiment of the present invention relates to a method of manufacturing a laminate by superimposing a film 3 made of a liquid crystal polymer that forms an optically anisotropic melt phase and a metal foil 4. . A first step (FIG. 1) for forming a transportable laminate formed by thermocompression bonding with the liquid crystal polymer film 3 and / or metal foils 4, 4 ′, and heat treatment while transporting the laminate 5 by cross-linking And a third step (FIG. 3) in which the laminate subjected to the second step is subjected to heat treatment.

  A 1st process can use a conventionally well-known thermocompression-bonding process only when forming a laminated body by thermocompression-bonding a liquid crystal polymer film and metal foil. For example, in order to stably obtain a laminate of uniform quality in the first step, as shown in FIG. 1, a film 3 made of a liquid crystal polymer that forms an optically anisotropic melt phase and metal foils 4, 4 Both or any one of 'is overlapped and passed between the pressure rolls 1, 1 ′, thereby laminating both or any one of the liquid crystal polymer film 3 and the metal foils 4, 4 ′. In particular, in the step of passing both or one of the liquid crystal polymer film 3 and the metal foils 4 and 4 ′ between the pressure rolls 1 and 1 ′, a heating booth 2 is appropriately provided outside the pressure rolls 1 and 1 ′. It is desirable to provide and heat or keep the liquid crystal polymer film 3, the metal foils 4, 4 ′ or both of them and the pressure rolls 1, 1 ′.

  The liquid crystal polymer film 3 is made of a liquid crystal polymer that forms an optically anisotropic melt phase. A liquid crystal polymer that forms an optically anisotropic melt phase is also called a thermotropic liquid crystal polymer. As is well known to those skilled in the art, a polymer that forms an optically anisotropic melt phase is a highly transparent material that transmits polarized light when a sample in a molten state is observed under a direct microscope with a polarizing microscope equipped with a heating device. Is a molecule.

The raw material of the liquid crystal polymer film 3 is not particularly limited, and examples thereof include known thermotropic liquid crystal polyesters and polyester amides derived from the compounds (1) to (4) exemplified below and derivatives thereof. be able to. However, in order to form a polymer liquid crystal, there is an appropriate range for each combination of raw material compounds.
(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

  Typical examples of the liquid crystal polymer obtained from these raw material compounds include a copolymer having a structural unit represented by the following formula.

  The liquid crystal polymer film preferably has a melting point temperature of 200 to 400 ° C., particularly 250 to 320 ° C. in terms of heat resistance and workability. Here, the melting point of the liquid crystal polymer film refers to a melting peak temperature in differential scanning calorimetry (DSC) when a film to be subjected to thermocompression bonding is heated at a rate of temperature increase of 10 ° C./min. The film may contain a lubricant, an antioxidant, a filler and the like as long as the characteristics of the film are not impaired.

  The liquid crystal polymer film is obtained by extrusion molding. Although any extrusion molding method can be applied, the known T-die method, laminate stretching method, inflation method and the like are industrially advantageous. In particular, in the laminate stretching method and the inflation method, stress is applied not only in the film conveyance direction (MD: Machine Direction) but also in the width direction (TD: Transverse Direction) orthogonal thereto, so that mechanical properties in MD and TD are applied. A film with balanced properties can be obtained.

  A preferable thickness range of the liquid crystal polymer film is 500 μm or less, more preferably 10 to 250 μm, and particularly preferably 15 to 150 μm. When the film thickness exceeds 500 μm, the film becomes rigid and difficult to wind in a roll shape, so handling is difficult. On the other hand, if the film thickness is less than 10 μm, the film may be easily torn and difficult to handle.

  The material of the metal foils 4 and 4 'is not particularly limited in the present invention. Examples include gold, silver, copper, stainless steel, nickel, and aluminum. Examples of metal foils that are preferably used include copper foils and stainless steel foils. As the copper foil, any copper foil produced by a rolling method or an electrolytic method can be used. The metal foil is subjected to physical surface treatment such as roughening treatment and chemical surface treatment such as acid cleaning within the range that does not impair the effect of the present invention, for the purpose of ensuring adhesion with the liquid crystal polymer film. May be.

  A preferable thickness range of the metal foil is 5 to 150 μm, more preferably 6 to 70 μm, and particularly preferably 9 to 35 μm. It is preferable to reduce the thickness of the metal foil from the viewpoint that a fine pattern can be formed. However, if the thickness is too thin, the metal foil is wrinkled in the manufacturing process, and a circuit is formed as a wiring board. In some cases, the reliability of the circuit board may be reduced, for example, the wiring may be broken. On the other hand, when the thickness of the metal foil is increased, the side surface of the circuit is tapered when the metal foil is etched, which is disadvantageous for fine pattern formation.

  The thermocompression bonding between the liquid crystal polymer film 3 and the metal foils 4 and 4 ′ is performed by the pressure rolls 1 and 1 ′, and usually a pair of pressure rolls is used. Examples of the pair of pressure rolls 1 and 1 ′ include a rubber roll, a metal roll, and a resin-coated metal roll. Although the pressure at the time of press-bonding by the pressure rolls 1 and 1 ′ is not particularly limited as long as it can be uniformly pressed in the width direction, it is preferably 5 to 200 kN / m, and preferably 10 to 40 kN / m. Is more preferable.

  When a pressure roll has a metal roll as a component, it is preferable to heat the inside with an internal heating means. For example, it is preferable to use a heating / pressurizing roll having a metal roll portion provided with a heating mechanism of a dielectric heating system or a heat medium circulation system.

  Various known processes can be adopted as the first process of the production method of the present invention. However, by carrying out the first step having the following characteristics as shown in FIG. 1, a laminate that can be wound up and transported stably in quality can be provided to the second step.

  The surface of the heating / pressurizing roll is preferably heated or kept warm from the outside of the roll. In FIG. 1, the heating booth 2 covers the entire pressure rolls 1, 1 ′ and keeps the heat.

  The structure of the heating booth 2 is preferably a sealed structure that surrounds the entire pressure roll and is further covered with a heat insulating material. It is preferable that the inside of the booth is heated so that the temperature within a specified range is kept constant. Although the heating method in a booth is not specifically limited, A hot air circulation blower, a ceramic heater, etc. can apply preferably. A fan may be installed in the booth. A structure in which a part of the booth can be released for the paper passing work and cleaning of the metal foil is preferable.

  Next, the 2nd process of the manufacturing method of the laminated body which concerns on this invention is demonstrated according to FIG. The laminate that can be wound and conveyed through the first step may be used in the second step after being wound into a roll, or may be used directly from the first step to the second step.

  In this invention, the range whose laminated body width is 70-1200 mm is suitable, and the range which is 200-640 mm is more preferable. When the laminated body width is less than 70 mm, the dimensional characteristics of the laminated body are less likely to vary, and the effect of the second step is small. On the other hand, when the laminated body width exceeds 1200 mm, the dimensions of equipment members including rolls are excessive, and temperature control tends to be difficult.

As shown in FIG. 2, in the second step of the present invention, the transportable laminate 5 obtained in the first step is cross-linked while maintaining its width direction (from the front side to the back side in the drawing) almost horizontally. It is preferable to perform the heat treatment at a temperature of 20 ° C. or lower than the melting point of the liquid crystal polymer while being conveyed. Moreover, it is preferable that the upper limit of the heat processing temperature of a 2nd process is below the temperature 10 degreeC higher than melting | fusing point of a liquid crystal polymer. Such heat treatment eliminates the tension of the liquid crystal polymer film that occurs when the metal foil is pressure-bonded between the heating rolls in the first step, the fluctuation of the molecule, and the change in molecular orientation due to the heating of the surface, etc. It becomes a laminated body with good property and dimensional stability. If the temperature is lower than the temperature related to the melting point, the tension and the molecular orientation change of the liquid crystal polymer film are not sufficiently eliminated, and good dimensional stability cannot be obtained. It is not preferable because melting occurs to deteriorate the appearance.
The laminated body thus treated is wound around a metal core by receiving a rotational torque (predetermined tension) of the winding device by a winding device (not shown).

In the second step, the means for the heat treatment is not limited, but it is preferable to use a heating furnace from the viewpoint that the laminate can be accurately heat-treated without contacting the laminate. When using a heating furnace, the kind is not specifically limited, A hot air type heating furnace, a hot air circulation type heating furnace, an infrared heater type heating furnace, etc. are illustrated as a preferable thing.
The winding device is not particularly limited, and can be used with a known device. Further, the material of the winding core is not limited to the metal core. As will be described later, a winding core having a structure capable of adjusting the diameter can also be used.

  In the third step of the present invention, heat treatment is performed after the second step for the purpose of improving the heat resistance and workability of the laminate. The type of the apparatus used at this time is not particularly limited as long as it is a furnace that can be heated in an inert gas atmosphere, and a batch type furnace is preferable because stable productivity is obtained. Moreover, regarding a heating system, an infrared heater type heating furnace, a graphite heater type heating furnace, a metal wire type heating furnace, etc. are illustrated as a preferable thing.

  The batch type furnace used in the third step is not particularly limited as long as the laminated body subjected to the second step can be brought into a heated state, but the range of the furnace volume of 8 to 500 L is suitable. The range of 40-300L is more preferable. If the furnace volume is less than 8 L, it is too small to contain the laminate roll 8 from the second step. On the other hand, if the volume of the furnace exceeds 500 L, the size of the equipment-like member becomes excessive and temperature control tends to be difficult.

In the third step, the laminate 5 that can be wound and conveyed through the second step is wound on a metal core 11 and then heated in a heating box as shown in FIG.
When heating, the method of unwinding and unfolding, and the method of shrinking the diameter of the core itself, from the outer laminate surface and the core surface where the laminate winding start end affixed to the core is unwound It can be set as the state which does not receive a contact pressure. With such a structure, the internal contact pressure can be reliably removed.
In the method of unwinding and unfolding, as shown in FIGS. 3A and 4, the laminate roll 8 is unwound in a state in which it is placed vertically (a state where the longitudinal direction of the core is perpendicular to the ground). It is preferable to develop. When changing the diameter of the core, in addition to working in a vertically placed state as described above, the work may be done in a horizontally placed state as shown in FIG.

  Moreover, in the laminated body which has a metal foil only on one side of the film, the outer laminated body surface and the inner laminated surface obtained by unwinding the laminated body portion 12 other than the laminated body winding start end 15 attached to the core 11. It is preferable that the contact pressure is not received. In this case, each laminate surface can be separated by 5 μm or more, more preferably, within a range of 30 μm or more and less than 10 cm, and this can be placed in the furnace as it is. If the separation distance formed at this time is less than 30 μm, the heat treatment may not sufficiently prevent the fusion due to thermal expansion in the thickness direction of the liquid crystal polymer film. Becomes excessive and the convenience of the furnace used for the heat treatment becomes difficult in terms of equipment.

  Specifically, as shown in FIGS. 4 and 5, unrolling and unfolding is performed on a metal tray 14 that receives the laminate roll, and the roll is unrolled from the winding core 11. It is preferable that the part has a guide ring 13 that can support the unrolled laminate 12 and has a diameter larger than the initial laminate roll diameter. The materials of the metal core, the metal tray and the guide ring are not particularly limited, but stainless steel and aluminum are preferable.

Specifically, in order to adjust the diameter of the core so as not to receive the contact pressure, the core shown in FIG. 6 is used.
As shown in FIG. 6, the core 21 has a cylindrical shape, and has a slit 22 along the axial direction on the outer peripheral wall of the core. As shown in FIG. 7, the opening width S of the slit 22 is preferably formed within a range of 5% or less of the outer circumference (entire circumference including the slit width) length L. By shrinking the opening width of the slit, the outer diameter of the core can be changed as shown in FIG.
In addition, a slit opening variable device 23 can be provided on the core 21. As the variable device, for example, as shown in FIG. 6, nut and bolt attachment members 24 and 25 are provided on the outer wall of each end across the slit. The attachment member 24 is provided with a nut 26 as a first engagement member, and the attachment member 25 is provided with a screw 27 as a second engagement member by bridging between the slits to adjust the screwing relationship. By doing so, the opening width of the slit is varied.
In the above embodiment, the variable device is formed by tightening the bolt and the nut. However, if the above effect is obtained by the engagement relationship of the engagement member made of the bridging member, the bolt and nut are screwed together. There is no limitation, and a variable device using an engagement relationship between the gear and the ratchet or other known engagement relationship may be used. Moreover, you may provide in either the inner side or the outer side of an outer wall.

When such a core 21 is fixed to the core support shaft (support shaft fixed by applying pressure to the inner periphery of the core, such as an air shaft) of the winding device, The opening width of the slit can be controlled by adjusting the pressure received by the peripheral portion from the support shaft, whereby the diameter can be arbitrarily changed. Further, by passing a bolt through the slit and allowing the slit opening width to be adjusted within the above 5% range by tightening or loosening the bolt, the diameter can be varied in a wider range.
The laminated body is wound around the core 21 with the slit 22 opened, and the slit 22 is closed and the diameter of the core 21 is reduced to form a space between the core 21 and the laminated body 16. The laminated body winding start end 15 attached to the core 21 is not brought into contact with the adjacent portion of the laminated body 16 (FIG. 7B). The opening width of the slit is a range in which the bolts are not bent when handed over, and there is no hindrance to tightening or loosening. More preferably, the opening width S is 2% or less of the core outer peripheral length L. It is.
When the core is subjected to heat treatment, the material is preferably metal, and stainless steel and aluminum are exemplified as preferable materials.

  When winding the laminated body around the winding core 21, other materials can be entrained as necessary. When an electric heating method is used for the heating method, it is necessary to ensure insulation between the roll layers, and therefore an insulating material is entrained. Although this insulating material has heat resistance and is not particularly limited as long as it does not have a surface shape that deteriorates the appearance of the laminate, a polyimide film is exemplified as a preferable material.

It is desirable that the winding tension when winding the laminated body or the accompanying winding material around the winding core 21 is 1 kgf or more and less than 7 kgf. When the winding tension is less than 1 kgf, the laminated body and the accompanying winding material are easily loosened during conveyance in the winding device, which may cause wrinkles. On the other hand, when the winding tension is 7 kgf or more, a strong stress is accumulated inside the roll after winding, which may cause the base material to buckle during heat treatment and deteriorate the appearance.
The core and the heat treatment method have been studied and developed for the purpose of producing a laminate composed of a liquid crystal polymer and a metal foil, but its use is not limited to the laminate, By appropriately adjusting the treatment conditions, for example, it is possible to apply to a wide range of winding laminates such as a laminate using a material other than the liquid crystal polymer, a resin film, and a metal foil.

  The heat treatment temperature in the third step is preferably not less than a temperature 30 ° C. lower than the melting point of the liquid crystal polymer and not more than 10 ° C. higher than the same melting point. More preferably, the temperature is in the range of 10-30 ° C. lower than the melting point of the liquid crystal polymer. When the heat treatment temperature is less than 30 ° C. lower than the melting point of the liquid crystal polymer, the heat resistance of the laminate is not sufficiently improved, and when the temperature exceeds 10 ° C. higher than the melting point of the liquid crystal polymer, the film is melted. Remarkably deteriorate the appearance.

  In the heat treatment of the third step, after reaching the heat treatment temperature, the heat treatment time maintained at that temperature is suitably in the range of 60 minutes to 240 minutes, and preferably in the range of 80 to 200 minutes. If the heat treatment time exceeds 240 minutes, the liquid crystal polymer film may be defective in appearance. In addition, if the heat treatment time is less than 60 minutes, the effect of improving the heat resistance and workability of the laminate may not be sufficient.

  The heat treatment in the third step is suitably performed in an inert gas atmosphere, and is preferably performed in a nitrogen gas atmosphere. When heat treatment is performed in air, the metal foil on the surface of the laminate may be discolored due to oxidation. After the heat treatment, after cooling, the atmosphere can be replaced with air, and the laminate can be taken out.

  The laminate obtained by the production method of the present invention has a good appearance, retains the excellent mechanical strength, electrical properties, chemical resistance and heat resistance of the liquid crystal polymer, and the film layer is a metal. It is firmly bonded to the foil not only at room temperature but also at high temperature. Therefore, it is useful as a material for producing FPC, TAB tape and the like.

In the above-mentioned best embodiment, the laminate has a structure of one liquid crystal polymer film and one or two layers of metal foil. However, the laminate manufactured in the present invention may be any layer as long as it includes at least one film and at least one metal foil. For example, the two-layer structure shown in the following (1) and the three layers (2) A structure, a four-layer structure of (3), or a five-layer structure of (4) can be exemplified.
In addition, in the manufacturing method of such embodiment, although it does not have the objective effect like a liquid crystal polymer, it can be applied to a general resin film.

(1) Metal foil / film (2) Metal foil / film / metal foil (3) Metal foil / film / film / metal foil (4) Metal foil / film / metal foil / film / metal foil

(Examples and Comparative Examples)
EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples.

  Evaluation of the laminates obtained in the examples was visually inferior in appearance (transfer marks caused by steps at the laminate winding start end affixed to the core, and buckling in the laminate layers other than the winding start end, etc. In the laminate having a metal foil only on one side of the liquid crystal polymer film, the presence or absence of transfer of the surface shape of the metal foil by fusion between the film and the adjacent metal foil is observed.

Example 1
In the first step, a 9 μm thick electrolytic copper foil is superimposed on both sides of a liquid crystal polymer film (trade name Bexter, melting point 280 ° C.) having a thickness of 50 μm, and at the same time, continuously at 1 m / min between a pair of pressure rolls. Supplied to. The roll was heated at 250-260 ° C. by an internal heating mechanism. The heating / pressurizing roll was placed in a booth, and the booth was heated to 200 to 230 ° C. by a hot air circulation blower.

  In the subsequent second step, the laminate was heat-treated with a hot air heating furnace. At this time, the heat treatment was performed by passing it through a hot-air heating furnace for about 100 seconds. The maximum temperature region in the furnace was 10 ° C. lower than the melting point of the liquid crystal polymer, and was continuously treated at 2 m / min. It wound up on the metal core with the take-off device.

In the subsequent third step, the laminated body wound up in a roll was placed in a vertically unwound state, left standing in a heating furnace, and then heated in a nitrogen atmosphere. Moreover, the nitrogen pressure in the furnace was 1 × 10 ⁵ Pa, the set heating temperature was 260 ° C., and after reaching the set temperature, the temperature was maintained for 90 minutes and the heat treatment was performed. The evaluation results of the obtained laminate are shown in Table 1.

(Comparative Example 1)
Like Example 1, it was set as the laminated body at the 1st process, and it heat-processed with the hot air type heating furnace in the following 2nd process. The subsequent third step was performed in the same manner as in Example 1 except that the roll-shaped laminate was placed in the furnace vertically without unwinding. The evaluation results of the obtained laminate are shown in Table 1.

(Example 2)
Like Example 1, it was set as the laminated body at the 1st process, and it heat-processed with the hot air type heating furnace in the following 2nd process. The subsequent third step was carried out in the same manner as in Example 1 to confirm the reproducibility of the effects of the invention. The evaluation results of the obtained laminate are shown in Table 1.

(Example 3)
In the first step, an electrolytic copper foil having a thickness of 9 μm was superposed on one side of a liquid crystal polymer film similar to that in Example 1, and continuously supplied at a rate of 1 m / min between a pair of pressure rolls. The roll was heated at 210-260 ° C. by an internal heating mechanism. The heating / pressurizing roll was placed in a booth, and the booth was heated to 230 ° C. by a hot air circulation blower.

  In the subsequent second step, the laminate was heat-treated with a hot air heating furnace. At this time, the heat treatment was performed by passing it through a hot-air heating furnace for about 200 seconds. The maximum temperature region in the furnace was 10 ° C. lower than the melting point of the liquid crystal polymer, and the heat treatment was continuously performed at 1 m / min. In the subsequent third step, each of the separated widths of the laminated body that was unrolled vertically was set to 5 μm to 80 μm, and heat treatment was performed under the same conditions as in Example 1. Table 2 shows the evaluation results of the obtained laminate.

(Comparative Example 2)
As in Example 3, a laminate was formed in the first step, and heat treatment was performed in a subsequent second step using a hot air heating furnace. In the following 3rd process, it carried out like Example 3 except having left the roll-shaped laminated body in the furnace by placing horizontally without unwinding. Table 2 shows the evaluation results of the obtained laminate.

Example 4
As in Example 3, a laminate was formed in the first step, and heat treatment was performed in a subsequent second step using a hot air heating furnace. The subsequent third step was carried out in the same manner as in Example 3 to confirm the reproducibility of the effects of the invention. Table 2 shows the evaluation results of the obtained laminate.

(Example 5)
As in Example 1, a laminate was formed in the first step, and in the subsequent second step, the laminate was subjected to heat treatment by a hot air heating furnace. At this time, the heat treatment was performed by passing it through a hot-air heating furnace for about 100 seconds. However, the maximum temperature region in the furnace was set at 270 ° C. and was continuously treated at 2 m / min. Winded up.
In the subsequent third step, as shown in FIG. 6 and FIG. 7 (a), the plastic core is applied to the core (stainless steel) having an outer peripheral length of 50 cm according to the present invention having an open width of 1 cm with the slit fully opened. After rewinding the laminated body wound up at a take-up tension of 1 kgf, a space is formed by closing the slit and reducing the diameter of the core, and the laminate winding start end attached to the core and the laminated The body layer was not in contact. This was left to stand in a heating furnace and then subjected to a heat treatment in a nitrogen atmosphere. Moreover, the nitrogen pressure in the furnace was 1 × 10 ⁵ Pa, the set heating temperature was 260 ° C., and after reaching the set heating temperature, the temperature was maintained for 90 minutes and the heat treatment was performed. Table 3 shows the evaluation results of the obtained laminate.

(Comparative Example 3)
Like Example 5, it was set as the laminated body at the 1st process, and it heat-processed with the hot air type heating furnace in the following 2nd process. In the subsequent third step, the laminated body was rolled up on a roll core (stainless steel cylinder) having an outer peripheral length of 50 cm without slits, wound up at a tension of 1 kgf, placed in a furnace and left standing. Performed as in Example 5. Table 3 shows the evaluation results of the obtained laminate.

(Example 6)
Like Example 5, it was set as the laminated body at the 1st process, and it heat-processed with the hot air type heating furnace in the following 2nd process. In the subsequent third step, the laminate wound around the plastic core is wound to a tension of 8 kgf on the core (made of stainless steel) of the present invention having an opening width of 1 cm with the slit fully opened. Then, the slit was closed and the diameter of the core was reduced to form a space, which was carried out in the same manner as in Example 5 except that it was placed in a furnace and left standing. Table 3 shows the evaluation results of the obtained laminate.

(Example 7)
Like Example 5, it was set as the laminated body at the 1st process, and it heat-processed with the hot air type heating furnace in the following 2nd process. In the subsequent third step, the same procedure as in Example 5 was performed except that a 75 μm-thick stainless steel foil and a 50 μm-thick polyimide film were wound together at a winding tension of 1 kgf on the laminate, and the accompanying winding material was included. The effectiveness of the effect of the invention was confirmed. Table 3 shows the evaluation results of the obtained laminate.

  The method for producing a laminate according to the present invention can stably produce a laminate suitably used for a metal-clad laminate for circuit boards, which requires high dimensional stability, while suppressing appearance defects in the production process. The industrial applicability is high.

It is a schematic explanatory drawing which shows the 1st process in the manufacturing method of the laminated body which concerns on this invention. It is a schematic explanatory drawing which shows the 2nd process in the manufacturing method of the laminated body which concerns on this invention. It is a schematic explanatory drawing which shows the 3rd process in the manufacturing method of the laminated body which concerns on this invention, (a) is a case where a laminated body is installed vertically, (b) is a schematic explanatory drawing in the case of placing horizontally. . It is a schematic explanatory drawing which shows a mode that the laminated body wound up by roll shape was unwound from a side surface. It is a schematic explanatory drawing which shows a mode that the laminated body wound up by roll shape was unwound from the upper surface. It is a perspective view which shows one embodiment of the winding core which can change the outer diameter used in the manufacturing method of the laminated body which concerns on this invention. FIG. 7 shows a state in which the outer diameter of the winding core shown in FIG. 6 changes, in which (a) shows a state in which the slit is opened, and (b) shows a state in which the laminate is wound with the slit closed. It is a schematic explanatory drawing which shows from above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 '... Pressure roll 2 ... Heating booth 3 ... Liquid crystal polymer film 4, 4' ... Metal foil 5 ... ······················································ 7 10 ........ Heating furnace 11... Metal core 12... Unrolled laminate 13. 14 .... Metal tray 15 .... Laminate end pasted on metal core 16 .... Laminate layer other than laminate end 21 ... ································································· 23 ·····Ne

Claims (11)

  In the method for producing a laminate having a metal foil on one side or both sides of a resin film, after laminating the film and the metal foil and winding it around a roll core, when the laminate roll is heat-treated In addition, at least a winding start end of the laminated body in the roll is heat-treated in a state where it does not receive contact pressure from the outer laminated body surface and the core surface.   The method for producing a laminate according to claim 1, wherein the state in which the contact pressure is not received is performed by unwinding and developing the roll.   The method for producing a laminate according to claim 1, wherein the state of not receiving the contact pressure is performed by changing the outer diameter of the core after winding the roll.   The winding core has a cylindrical shape, has a slit in the axial direction of the outer peripheral wall of the winding core, and has an opening width within 5% of the outer peripheral length. 4. The method for manufacturing a laminate according to claim 3, wherein the outer diameter of the core is reduced by changing the width.   The winding core is provided with a variable device for the opening width of the slit, and the variable device is provided at a first engagement member provided on the outer wall at one end between the slits and at the other end between the slits, and between the slits. The slit is opened by adjusting the engagement relationship between the first engagement member and the second engagement member. The method for producing a laminate according to claim 4, wherein the width is changed.   Heat treatment is performed in a state in which the laminated body other than the winding start end is not subjected to contact pressure, and the winding laminated bodies in the roll are separated from each other by 5 μm or more. The manufacturing method of the laminated body as described in any one term.   The winding laminate roll is a metal core after heat-treating the transportable laminate formed by thermocompression bonding the film and the metal foil in the first step in the second step. The method for producing a laminate according to any one of claims 1 to 6, wherein the laminate is wound into a roll.   The said resin film is a liquid crystal polymer film, The temperature in the said heat processing is 30 degreeC or more lower than the melting | fusing point of this film, and is 10 degrees C or less higher than the same melting point, The claim in any one of Claims 1-7 The manufacturing method of the laminated body of description.   The manufacturing method according to claim 8, wherein, in the heat treatment, after reaching the heat treatment temperature, the heat treatment time maintained at the temperature is in a range of 60 minutes to 240 minutes.   The manufacturing method of the laminated body in any one of Claims 1-9 which perform the said heat processing in inert gas atmosphere.   The said film is a thermotropic liquid crystal polymer, The manufacturing method of the laminated body in any one of Claims 1-10.

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