JP2007268716A - Method for producing laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate manufacturing method which stably produces a laminate suitable for a metal-clad laminate for a circuit board required for high dimensional stability. <P>SOLUTION: In the method for producing the laminate by laminating metal foil on film made of a liquid crystal polymer forming an optically anisotropic molten layer, a windable/conveyable laminate formed by hot-pressing the film and the metal foil in the first process, while being conveyed, is heat-treated at a temperature lower by 10°C than the melting point of the liquid crystal polymer in the second process. The temperature distribution of a conveyance region ranging from 200°C to the maximum heating temperature in the temperature elevation process of the laminate is made ≤±5°C in each position in the width direction. <P>COPYRIGHT: (C)2008,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 film composed of a liquid crystal polymer capable of forming an optically anisotropic melt phase (hereinafter also referred to as a liquid crystal polymer film). It is related with the manufacturing method of the laminated body which overlaps and metal foil.

  In general, a liquid crystal polymer film is known as a material excellent in high heat resistance, hygroscopic dimensional stability, high frequency characteristics, and the like. Focusing on such characteristics of the liquid crystal polymer film, it has been studied to use it for an insulating material of an electronic circuit board. When used for an electronic circuit board, a laminate of a liquid crystal polymer film and a metal foil typified by a 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. There is a method in which a liquid crystal polymer film cut to a predetermined size and a metal foil are placed between the upper and lower hot plates of a hot press apparatus, and then 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 laminated body having a uniform quality in terms of peel strength, etc., and the production speed per laminated body becomes slow, resulting in a cost reduction. It has the disadvantage of becoming expensive.

  Therefore, in order to increase the production speed at a low cost, a method for continuously producing a laminate has been proposed (see, for example, Patent Document 1). By overlapping the liquid crystal polymer film and the metal foil and passing between the pressure rolls, the film and the metal foil are within a range from a temperature 80 ° C. lower than the melting point of the liquid crystal polymer to a temperature 5 ° C. lower than the melting point. The pressure roll is allowed to pass through in a state where it is pressure-bonded at the temperature. And passing the film between a heating and pressing roll containing 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. It is assumed that the metal foil is pressure-bonded.

  Moreover, in order to provide the metal-clad laminate for circuit boards excellent in dimensional stability with high productivity, the first step of thermocompression bonding of the liquid crystal polymer film and the metal foil was obtained in the first step. A manufacturing method has been proposed that includes a second step of heat-treating the laminate at a temperature equal to or higher than the melting point of the liquid crystal polymer film (see, for example, Patent Document 2). In Patent Document 2, when the thermoplastic liquid crystal polymer film and the metal foil are pressure-bonded between the heating rolls in the first step, tension is applied to the thermoplastic liquid crystal polymer film, and the molecules easily change. In the conventional metal-clad laminate, changes in molecular orientation are likely to occur on the film surface with heating, and a metal-clad laminate with good isotropy and dimensional stability cannot be obtained. To do.

  Patent Document 2 proposes that after heat-pressing the liquid crystal polymer film and the metal sheet, heat treatment is performed in a hot-air circulating dryer or in a hot-air heat treatment furnace at a temperature equal to or higher than the melting point of the liquid crystal polymer film. According to the knowledge of the present inventors, the mere disclosure disclosed here is insufficient to improve the dimensional variation of the resulting laminate, even though the dimensional stability can be improved to some extent.

Moreover, regarding a hot stove, it is disclosed by patent document 3, for example. However, the usage mode of a general hot stove has not been determined, and it is not shown how to apply it to the manufacture of a laminate of a metal foil and a liquid crystal polymer film, which is the subject of the present invention.

JP-A-5-42603 JP 2000-343610 A JP 2000-216532 A

  The present invention provides a method for producing a laminate that can stably produce a laminate suitably used for a metal-clad laminate for circuit boards that requires high dimensional stability while suppressing dimensional variations. Objective.

  In order to solve the above-mentioned problems, the present inventors have conducted intensive studies. As a result, when manufacturing a laminate by laminating a liquid crystal polymer film and a metal foil, to the laminate in the heat treatment step after thermocompression bonding and lamination. By controlling the heat treatment in a specific condition, the liquid crystal polymer film and the metal foil are sufficiently bonded at each position in the plane, and a good laminate with little dimensional variation is obtained at each position in the plane. The present invention was completed by finding that it can be stably obtained.

  That is, the present invention relates to a laminate manufacturing method for manufacturing a laminate by laminating a film made of a liquid crystal polymer that forms an optically anisotropic melt phase and a metal foil, in the first step, the film and the In a second step of performing heat treatment at a temperature lower than the melting point of the liquid crystal polymer by 10 ° C. or higher while transporting the transportable laminate formed by thermocompression bonding with the metal foil, 200 in the temperature increasing process of the laminate is performed. It is a method for producing a laminate, wherein the temperature distribution in the conveyance region from 0 ° C. to the maximum heating temperature is within ± 5 ° C. at each position in the width direction.

  According to the present invention, in the so-called second step after laminating a liquid crystal polymer film and a metal foil, a laminate having excellent dimensional characteristics is produced by transporting the laminate while reducing temperature variations in the width direction. It is possible to manufacture with good performance. The laminate produced here is not damaged by the high heat resistance, moisture absorption dimensional stability, high frequency characteristics, etc. possessed by the liquid crystal polymer, and is excellent in adhesion to metal foil. It is useful as a laminate used for a representative wiring board.

  Hereinafter, the manufacturing method of the laminated body which concerns on this invention is explained in full detail, referring an accompanying drawing as needed. The following embodiments and examples do not limit the production method of the laminate of the present invention.

  The present invention is a method for producing a laminate by laminating a film made of a liquid crystal polymer that forms an optically anisotropic melt phase and a metal foil, and the film 4 and the metal foils 5 and 5 ′ are heated. A first step (see FIG. 1) for forming a laminate that can be wound and conveyed formed by pressure bonding, and a heat treatment at a temperature of 10 ° C. lower than the melting point of the liquid crystal polymer while the laminate 6 is conveyed by crosslinking. Two steps (see FIGS. 2 and 4) are essential manufacturing steps. In FIG. 1, two metal foils 5 and 5 ′ are shown, but the present invention is applicable even if one of them is used.

  First, the 1st process of the manufacturing method of the laminated body which concerns on this invention can use the conventionally well-known thermocompression bonding process, as long as a film and metal foil are thermocompression-bonded and a laminated body is formed. For example, in order to stably obtain a laminate of uniform quality in the first step of the present invention, as shown in FIG. 1, a film 4 made of a liquid crystal polymer that forms an optically anisotropic molten phase and a metal The film 4 and the metal foil 5, 5 ′ are laminated by overlapping the foils 5, 5 ′ and passing between the pressure rolls 1, 1 ′. In particular, in the step of passing the film 4 and the metal foil 5, 5 ′ between the pressure rolls 1, 1 ′, the heating means 2, 3 are provided outside the pressure rolls 1, 1 ′, and the film 1, It is desirable to heat or insulate the metal foils 5 and 5 ′ and the pressure rolls 1 and 1 ′.

  The film 4 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 a melt phase that forms optical anisotropy is polarized when observing a sample in a molten state under a direct microscope with a polarizing microscope equipped with a heating device. Is a polymer that permeates.

The raw material of the liquid crystal polymer of the film 4 is not particularly limited, but known thermotropic liquid crystal polyesters and polyesteramides derived from the compounds (1) to (4) and derivatives thereof exemplified below. Can be mentioned. 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 350 ° C. in the following measurement methods in terms of heat resistance and workability. Here, melting | fusing point of said liquid crystal polymer film means the melting peak temperature in a differential scanning calorimetry method (DSC) when the film used for thermocompression bonding is heated at the temperature increase rate of 10 degree-C / min. The film may be blended with 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 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 orthogonal to the film direction (TD direction). A balanced film is obtained.

  A preferable thickness range of the liquid crystal polymer film is 500 μm or less, more preferably 10 to 500 μm, and particularly preferably 50 to 250 μm. When the film thickness exceeds 500 μm, the film becomes rigid and difficult to handle, such as being difficult to wind in a roll. On the other hand, if the film thickness is less than 10 μm, the film is easily torn and difficult to handle.

  The material of the metal foil 5, 5 '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 manufactured by a rolling method or an electrolysis method can be used. The metal foil is subjected to physical surface treatment such as roughening treatment or chemical surface treatment such as acid cleaning for the purpose of ensuring the adhesive strength with the liquid crystal polymer film, as long as the effect of the present invention is not impaired. 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 18 μm. Although it is preferable to reduce the thickness of the metal foil from the point that a fine pattern can be formed, if the thickness is too thin, the metal foil may be wrinkled in the manufacturing process, and a circuit may be formed as a wiring board. In such a case, the wiring may be broken or the reliability of the circuit board may be lowered. 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 of the liquid crystal polymer film 4 and the metal foils 5 and 5 'is performed between 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. In particular, at least one of them is desirably a resin-coated metal roll having a resin coating layer having a thickness of 0.02 to 5 mm on the surface of the metal roll. The other one is suitably a rubber roll, a metal roll, or a resin-coated metal roll, but it is desirable to use a resin-coated metal roll having a resin coating layer in the same thickness range as described above. In order to improve the adhesion between the liquid crystal polymer film and the metal foil, and also to keep the pressure roll surface temperature constant, the above resin-coated metal roll is used, and the thickness of the coating layer is within the above range. Is desirable. 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. It is more preferable.

  In the case of at least one of the pressure rolls, particularly the resin coating layer metal roll, it is preferable to heat the metal roll portion inside the pressure roll 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. Such heating is preferable from the viewpoint of making the surface temperature of the pressure roll uniform. The material of the resin coating layer includes rubber, and specifically, a material having high heat resistance and elasticity such as fluorine rubber, silicon rubber, and polyimide is preferable. In the present invention, since thermocompression bonding to the liquid crystal polymer film is usually performed at a temperature 20 to 60 ° C. lower than the melting point of the liquid crystal polymer, the heat resistance temperature of the resin coating layer is also required to be heat resistance in this temperature range. The resin coating layer may be composed of only a single layer or a plurality of resin layers.

Various known processes can be adopted as the first process of the production method of the present invention. However, by performing the first step having the following characteristics as shown in FIG. 1, it is possible to provide a laminated body that can be wound and transported in a stable quality to the second step.
In FIG. 1, the heating means 2 is a heating booth that covers the entire pressure rolls 1, 1 ′. The surface of the heating / pressurizing roll needs to be heated or kept warm from the outside of the roll. As a method of heating or keeping warm, a method of arranging a pressure roll in the booth or a method of installing a furnace immediately before the pressure roll is preferable. As will be described later, it is more preferable to use both a method of arranging a pressure roll in the booth and a method of installing the furnace 3 immediately before the pressure roll.

  The structure of the heating booth 2 is a sealed structure that surrounds the entire pressure roll, and is preferably covered with a heat insulating material. The inside of the booth is heated, and it is preferable to keep the temperature in the specified range described above constant. The heating method in the booth is not particularly limited, but a hot air circulation blower, a ceramic heater, or the like is preferable. Fans may be installed in the booth. A structure in which a part of the booth can be opened is preferable for the paper passing work and cleaning of the metal foil.

  Moreover, the heating means 3 shown in FIG. 1 is a furnace installed in the front | former stage of the nip part of a pressure roll. The inside of the furnace is preferably maintained in a range from a temperature 5 ° C. lower than the melting point of the liquid crystal polymer to a temperature 150 ° C. lower than the melting point, particularly in a range from a temperature 40 ° C. lower than the melting point to a temperature 100 ° C. lower than the melting point. . When the temperature is lower than 150 ° C. above the melting point, wrinkles may occur. When the temperature is 5 ° C. lower than the melting point, the film may be cut in the furnace.

Next, the 2nd process of the manufacturing method of the laminated body concerning this invention is demonstrated according to FIG.
The laminate that can be wound and conveyed in the first step may be used in the second step after being wound up in a roll, or may be applied directly from the first step to the second step. In the present invention, the film and the metal foil in the form wound in the roll form in the first step are prepared, and the film is continuously conveyed by roll-to-roll, and the productivity is improved by pressure bonding in the process. A process is desirable.

  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 in 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 laminate 6 that can be transported in the first step is maintained substantially horizontally in the width direction (from the front side of the drawing to the heel direction) and is bridged almost horizontally. There is a second step in which heat treatment is performed at a temperature of 10 ° C. lower than the melting point of the liquid crystal polymer while being conveyed. The upper limit of the heat treatment temperature in the second step is desirably 10 ° C. or higher than the melting point of the liquid crystal polymer. Above this temperature, the film will melt. On the other hand, when the heat treatment temperature is less than 10 ° C. lower than the melting point of the liquid crystal polymer, the heat resistance and workability of the laminate are not improved. In the heat treatment in the second step, the temperature distribution in the conveyance area in the temperature rising process from at least 200 ° C. to the maximum heating temperature is ±± at each position in the width direction of the laminate (arbitrary conveyance positions are the same as each other). It is necessary to control within 5 ° C. That is, after reaching the maximum heating temperature in the second step, for example, when the temperature is lowered in the furnace, the temperature distribution at each position in the width direction is not necessarily controlled within ± 5 ° C. However, it is preferable to control the temperature distribution in the width direction within ± 5 ° C. as much as possible within the range in which the temperature of 70 ° C. is lowered from the maximum heating temperature from the viewpoint of further improving the accuracy of dimensional variation. If the temperature variation in this process cannot be controlled within ± 5 ° C., the dimensional variation of the laminated body to be manufactured becomes large, which makes it unsuitable as a wiring board laminated body.

  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. In the present invention, the temperature raising process (or heating conveyance area) up to the position where the maximum heating temperature in the second step is reached can be rapidly raised in a short time, or a plurality of furnaces with different temperature settings can be slowly set. Both can be employed in combination and raising the temperature stepwise. Here, in the case where the temperature raising process up to the position where the maximum heating temperature of the laminated body is reached is rapidly raised in a short time, it is desirable to perform heating at an average temperature rising rate of 15 to 30 ° C./second. In addition, when the temperature raising process up to the position where the maximum heating temperature is reached is gradually raised in combination with a plurality of heating furnaces having different temperature settings, an average temperature raising rate of 0.5 to 1 ° C / It is desirable to perform heating in the range of seconds (see FIG. 4). When a plurality of furnaces with different temperature settings are combined to raise the temperature stepwise, the temperature difference from the adjacent heating furnace is preferably in the range of 10 to 30 ° C, particularly in the range of 10 to 20 ° C.

  When heat is applied to the laminate using a gas (thermal fluid) flow, such as a hot air heating furnace or a hot air circulating heating furnace, the temperature distribution control in the heating furnace is controlled in the heating furnace. It is preferable to control the flow of hot air in the furnace by an installed baffle plate or baffle plate (in this specification, unless otherwise specified, these are referred to as a baffle plate). The shape of the current plate used is not particularly limited. For example, as shown in FIG. 3A, a rectangular flat plate processed into a comb shape or a combination of two pieces can be slid. The thing made into was preferable. It is also possible to finely adjust the flow rate by sliding a combination of two current plates shown in FIG.

When the rectifying plate is installed in the furnace, it is preferable that the rectifying plate is installed substantially vertically with respect to the longitudinal direction of the laminate as shown in FIG. By installing the rectifying plate in the region up to the maximum heating temperature in the furnace, the temperature distribution in the width direction of the laminate can be controlled more finely, which in turn is effective in suppressing in-plane variations in the dimensional stability of the laminate. Is. Interval for installing the rectifying plate (t _1), the size of the furnace, when the distance to the laminate (t _2/2) is affected by such, tried with the laminate longitudinal, 5 cm the distance to the laminate When it is within the range, a range of 5 to 20 cm is preferable, and a range of 10 to 13 cm is more preferable. Moreover, it is preferable that a hot air shall be 5-10 m / min.

  In the laminate obtained by such a manufacturing method, the temperature distribution in the conveyance region in the temperature rising process from 200 ° C. to at least the maximum heating temperature is controlled within ± 5 ° C. at each position in the width direction of the laminate. Therefore, it has a good shape, the film layer has the excellent mechanical strength, electrical properties and heat resistance of the liquid crystal polymer, and the film layer is not only at the metal foil and normal temperature conditions but also at high temperature conditions It is firmly bonded even underneath. Therefore, it is useful as a material for producing FPC, TAB tape and the like.

  In the above-mentioned best embodiment, the laminated body has a structure of one liquid crystal polymer film and one or two metal foils. However, the laminate produced in the present invention may be any layer as long as it includes at least one liquid crystal polymer film and at least one metal foil. For example, the two-layer structure shown in the following I), II) Examples of the three-layer structure shown in IV), the four-layer structure of V), and the five-layer structure of VI) can be exemplified. In the following I) to VI), in the case of a laminate having two or more films, at least one film in contact with the metal foil is a liquid crystal polymer film.

I) Film / metal foil II) Metal foil / film / metal foil III) Film / film / metal foil IV) Film / metal foil / film V) Metal foil / film / film / metal foil VI) Metal foil / film / metal Foil / film / metal foil

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples. In addition, evaluation of the laminated body obtained in the Example is based on the following method.

<Method for evaluating laminate>
(1) Appearance: A laminate obtained by pressure-bonding a liquid crystal polymer film and a metal foil and a film obtained by etching the metal foil were observed visually and with an optical microscope to examine the presence or absence of deformation.
(2) Delamination strength: The delamination strength at room temperature was measured by peeling a metal foil having a width of 1 mm from the metal foil removal surface at 180 °.
(3) Dimensional change rate after cumulative heating, dimensional change rate variation:
The dimensional change rate and the in-plane variation σ are obtained as follows in accordance with IPC-TM650.2.4.4. That is, the copper-clad laminate (the liquid crystal polymer layer surface) cut out in a sheet shape is marked with 25 points (L = 50 mm) equally in the longitudinal direction and the width direction so as to include the center point, The change rate (dimensional change rate) before and after removing the copper foil was measured for a total of 40 spaced dimensions, and 3 times the standard deviation was defined as the in-plane variation 3σ. In addition, the sample after copper foil removal is heat-processed in a stationary state at 200 degreeC for 30 minutes. Here, the dimensional change rate (%) was calculated by the following equation, and the standard deviation was defined as the in-plane variation σ.
Dimensional change rate (%) = (length after removing copper foil−length before removing copper foil) / length before removing copper foil × 100

Two types of heating furnaces used in the present invention are shown below.
<Heating furnace A>
2 is a hot-air heating furnace shown in FIG. 2, in which a plurality of comb-shaped baffle plates made of stainless steel as shown in FIG.
It is a hot air type heating furnace shown in FIG. 4, and consists of three units of heating furnace.

Example 1
An electrolytic copper foil with a thickness of 18 μm was superposed on both sides of a liquid crystal polymer film (trade name Bexter, melting point 280 ° C.) having a thickness of 25 μm and simultaneously supplied at a rate of 2 m / min between a pair of pressure rolls. . The roll surface was heated to 230 ° C. by a heating mechanism inside the roll. The heating / pressurizing roll was placed in the booth, and the booth was heated to an arbitrary set temperature by a hot air circulation blower.

  In the subsequent second step, the laminate was subjected to a heat treatment using a hot air heating furnace. At this time, the heat treatment was performed by passing through a hot-air heating furnace. The furnace region was divided into a temperature region from 200 ° C. to the maximum heating temperature (region A), a maximum heating temperature region (region B), In addition, the temperature variation at each position in the width direction was controlled within ± 5 ° C. in each of the positions of the respective transport regions when the region (region c) was lower than the maximum heating temperature within 10 ° C. after the region B. . Here, in the area A, the temperature was increased from 200 ° C. at an average rate of temperature increase of 30 ° C./second, and in the area B, heated at 277 ° C. for 2 minutes and then passed through the area 270 ° C. The heating furnace A shown in FIG. 2 was used as the heating furnace. In addition, the liquid crystal polymer film and the electrolytic copper foil were continuously manufactured by a roll-to-roll method using a roll-shaped material as a raw material. The evaluation results of the obtained laminate are shown in Table 1.

(Example 2)
The laminated body which passed through the 1st process was made like Example 1, and the laminated body was heat-processed with the hot air type heating furnace in the following 2nd process. At this time, the heat treatment was performed by gradually raising the temperature by passing through a hot-air heating furnace. The furnace area was set to a temperature area (area A ′) having an average furnace temperature of 240 ° C. The temperature of each position in the width direction at each position of the transfer region when the temperature region (region b ′) with an average temperature of 260 ° C. and the temperature region (region c ′) with an average temperature in the furnace of 277 ° C. are set. Variation was controlled within ± 5 ° C. The average rate of temperature increase from 200 ° C. to the maximum heating temperature was 1 ° C./second. The heating furnace B shown in FIG. 4 was used as the heating furnace. In addition, the liquid crystal polymer film and the electrolytic copper foil were continuously manufactured by a roll-to-roll method using a roll-shaped material as a raw material. The evaluation results of the obtained laminate are shown in Table 1.

(Comparative Example 1)
In the same manner as in Example 1, the laminated body was subjected to the first step, and in the subsequent second step, the laminated body was subjected to heat treatment using a hot air heating furnace.
In the subsequent second step, the laminate was subjected to a heat treatment using a hot air heating furnace. At this time, the heat treatment was performed by passing through a hot-air heating furnace. The furnace region was divided into a temperature region from 200 ° C. to the maximum heating temperature (region A), a maximum heating temperature region (region B), In addition, the temperature variation of each position in the width direction is within ± 5 ° C at the position of any transport region in region B and C when the region is within 10 ° C lower than the maximum heating temperature after region B (region C) However, the temperature variation of the position in the width direction of the region A could be controlled only within a range of ± 7 ° C. Here, in the area A, the temperature was increased from 200 ° C. at an average rate of temperature increase of 30 ° C./second, and in the area B, heated at 277 ° C. for 2 minutes and then passed through the area 270 ° C. The heating furnace A shown in FIG. 2 was used as the heating furnace, but the width of the baffle plate in the area A was about half that of the first embodiment. In addition, the liquid crystal polymer film and the electrolytic copper foil were continuously manufactured by a roll-to-roll method using a roll-shaped material as a raw material. The evaluation results of the obtained laminate are shown in Table 1.

(Comparative Example 2)
The same operation as in Example 1 was performed except that the heating furnace used was not provided with the baffle plate of the heating furnace A. In any of the areas A, B, and C, the temperature variation in the width direction could be controlled only within a range of ± 7 ° C. The evaluation results of the obtained laminate are shown in Table 1.
In addition, about the laminated body manufactured in Example 1 and 2, the external appearance and delamination strength were measured. As a result, none of the laminates was deformed, and the 1 mm width delamination strength was 1.2 kN / m, which was favorable.

  INDUSTRIAL APPLICABILITY The laminate manufacturing method of the present invention is an industrial application that can stably manufacture a laminate suitably used for a metal-clad laminate for circuit boards that requires high dimensional stability while suppressing dimensional variations. The possibility is high.

It is a schematic explanatory drawing which shows an example of the 1st process in the manufacturing method of the laminated body which concerns on this invention. It is schematic explanatory drawing 1 which shows an example of the 2nd process in the manufacturing method of the laminated body which concerns on this invention. It is an example figure of the baffle plate (baffle plate) used at the 2nd process in the manufacturing method of the laminated body which concerns on this invention. It is schematic explanatory drawing 2 which shows an example of the 2nd process in the manufacturing method of the laminated body which concerns on this invention.

Explanation of symbols

1, 1 '... pressure roll 2 ... heating booth (heating means)
3 .... Furnace (heating means)
4 ... Film 5 ... Metal foil 6 ... Laminate 7 ... Crosslinking roll 8 ... Heating furnace

Claims (6)

In the method for producing a laminate, a film made of a liquid crystal polymer that forms an optically anisotropic melt phase and a metal foil are laminated to produce a laminate,
In the second step, the transportable laminate formed by thermocompression bonding of the film and the metal foil in the first step is subjected to heat treatment at a temperature of 10 ° C. or lower than the melting point of the liquid crystal polymer while being transported. A method for producing a laminate, characterized in that a temperature distribution in a conveying region from 200 ° C. to a maximum heating temperature in a temperature raising process of the laminate is within ± 5 ° C. at each position in the width direction. In the second step, in the temperature rising process before the position at which the maximum heating temperature is reached, the heating treatment for the laminated body at the position at which the temperature reaches 200 ° C to the maximum heating temperature is performed by a heating furnace provided in the transport zone. The manufacturing method of the laminated body of description. The temperature distribution in the heating furnace is controlled by flowing a thermal fluid into the heating furnace, and controlling the temperature distribution by regulating the flow of the thermal fluid with an installed rectifying plate or baffle plate. Method. The manufacturing method of the laminated body of Claim 2 or 3 which heats the temperature rising in the temperature rising process before the position which reaches the maximum heating temperature of a 2nd process in the range of average temperature rising rate 15-30 degreeC / sec. The manufacturing method of the laminated body of Claim 2 which heats the temperature increase in the temperature rising process before the position which reaches the maximum heating temperature of a 2nd process in the range of an average temperature increase rate of 0.5-1 degree-C / sec. The method for producing a laminate according to claim 5, wherein the temperature rise in the temperature raising process before the position reaching the maximum heating temperature in the second step is performed stepwise in a range of 10 to 30 ° C.

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