JP2019093548A - Long polyimide laminate and method for producing the same - Google Patents

Abstract

To provide a polyimide material capable of stably providing a flexible printed wiring board (FPC) that prevents positional deviation when being connected to other component and a circuit material even when a wiring width and an interval formed on the FPC are made to be extremely small.SOLUTION: A polyimide laminate has a thermoplastic polyimide resin layer on at least one surface of a non-thermoplastic polyimide film, when the width is set at 150 mm or more, a heat shrinkage ratio in the longitudinal direction of the film at a glass transition temperature of the laminate is represented by α and a heat shrinkage ratio in the width direction thereof is represented by β, 2.1<α<0.1, -2.5<β<-0.5 and -0.1<α×β<6.0 are satisfied. In the polyimide laminate, preferably, the glass transition temperature of the polyimide laminate is 100-300°C.SELECTED DRAWING: None

Description

  The present invention relates to a polyimide film having a small dimensional change rate.

  A polyimide film is used as a substrate of a flexible printed wiring board. Adhesive layer from printed wiring board using 3-layer flexible metal-clad laminate in which metal foil is pasted to insulating film via thermosetting adhesive along with weight reduction, miniaturization and high functionality of electronic products in recent years The demand is shifting to a flexible printed wiring board (hereinafter also referred to as a two-layer FPC) using a two-layer flexible metal-clad laminate (hereinafter also referred to as a two-layer FCCL) using a thermoplastic polyimide.

  As a typical manufacturing method of the two-layer FPC, there is a method of bonding while heating a metal foil to a laminate in which a thermoplastic polyimide layer is provided on a polyimide film. When manufacturing two-layer FCCL industrially, it bonds together using a heat | fever roll laminating apparatus or a double belt press apparatus, drawing | feeding out continuously the said roll-shaped wide laminated body and metal foil.

  A circuit is formed on the metal foil portion by etching etc. using the two-layer FCCL obtained in this way, and a two-layer FPC is manufactured. However, when the dimensional change after processing into the FPC becomes large, There is a problem that the position of the circuit deviates from the component mounting position, and the connection between the component to be mounted and the FPC can not be established.

  On the other hand, conventionally, the problem of dimensional change in the processed FPC is considered to be caused by the large thermal expansion coefficient and the hygroscopic expansion coefficient of the polyimide film and the high water absorption coefficient. That is, it is considered that the wiring as designed can not be formed because the dimensional change of the polyimide film due to heat or water absorption in the processing steps of FCCL and FPC is larger than the dimensional change of the metal foil. For this reason, efforts have been made to a polyimide film having a thermal expansion coefficient equivalent to that of a metal foil, and a polyimide film having a low hygroscopic expansion coefficient and a low water absorption coefficient. For example, in patent document 1, the problem of a dimensional change and heat resistance is solved by selecting the composition of a polyimide film.

  By the way, a heat shrinkage rate may be measured as a physical property of a polyimide film. It is considered that a lower heat shrinkage rate is better. As also described in Patent Document 1, the heat shrinkage ratio is often measured at a temperature in the range of 150 ° C. to 250 ° C. for 30 minutes to 1 hour of heating. This is often used to predict dimensional change when mounting a component on a flexible printed wiring board substrate by soldering, lamination of an anisotropic conductive film, or the like.

  A film-like bonding member in which an adhesive layer containing a thermoplastic polyimide is formed on one side or both sides of a polyimide film, and the dimensional change rate in the TD direction when heated at 250 ° C. for 30 minutes is -0.01% to- Patent Document 2 discloses an adhesive bonding member which is 0.10% and has a dimensional change rate in the MD direction of + 0.01% to + 0.10%. The dimensional change rate in the TD direction when heated at 250 ° C. for 30 minutes is the size of the film-like bonding member and the size after the metal layer is laminated thereon and the one removed by etching under the above conditions. Ratio. According to Patent Document 2, the dimensional change rate of FCCL can be improved by previously providing dimensional distortion that cancels dimensional change in the MD direction and TD direction generated by thermal lamination in film-like bonding, that is, dimensional change during heating. Have been described.

  As described above, various efforts have been made to the problem of dimensional change, but with the miniaturization and high performance of electronic devices, the miniaturization and thinning of FPC wiring are also progressing, and the dimensional change required for polyimide materials is required. The level of rates has become quite high, and the dimensional change issues are becoming more difficult to solve as the technology advances.

Japanese Patent Publication "Japanese Patent Application Publication No. 2007-196670" (August 9, 2007) Japanese patent publication "Japanese Patent Application Laid-Open No. 2005-335102" (December 8, 2005)

  As the level of dimensional change required increases, conventional approaches alone have become inadequate. That is, as the width and interval of the wiring formed on the FPC become smaller, the dimensional change which has not been a problem in the conventional FPC also becomes a problem. In particular, when FCCL is manufactured by the thermal laminating method, and particularly by the heat roll laminating method, the FCCL manufacturers set different manufacturing conditions, so it would be a problem when manufactured by another laminating method. It is judged that the dimensional change rate is large depending on the manufacturing conditions and the specifications used by FCCL manufacturers and FPC manufacturers, where the problem of dimensional change occurs or the polyimide material which has conventionally been considered to have a small dimensional change rate. The case is coming out. In addition, when two-layer FCCL is continuously manufactured and processed into FPC, there is a problem that parts with large or small dimensional change rate are different depending on the part, and it can not be predicted, and variation between lots Problems are also included. Therefore, it becomes an issue in the industry to provide a polyimide material that can stably provide an FPC that does not generate positional deviation when making connections with other parts and circuit materials even if extremely fine wiring is formed. is there.

The present inventors can solve the above problems by the following novel polyimide laminates.
1) A polyimide laminate having a thermoplastic polyimide resin layer on at least one surface of a non-thermoplastic polyimide film, wherein the laminate has a glass transition point, a width of 150 mm or more, and a glass transition of the laminate Assuming that the heat shrinkage ratio α in the longitudinal direction of the film at the temperature and the heat shrinkage ratio β in the width direction of the film at the glass transition temperature, −2.1 <α <0.1, −2.5 <β <−0. 5 and a range of −0.1 <α × β <6.0.
2) The polyimide laminate according to 1), wherein the glass transition temperature of the polyimide laminate is 100 to 300 ° C.
3) The polyimide laminate is obtained by applying and drying a solution containing at least one of a thermoplastic polyimide precursor and a thermoplastic polyimide on at least one surface of a non-thermoplastic polyimide film. The manufacturing method of the polyimide laminated body as described in 1, and 2).

  The dimensional change after removing the metal foil using the polyimide film laminate of the present invention is 0 ± 0.025% in both the MD and TD directions, and the in-plane variation is σ = 0. It can provide an FCCL of 030%.

It is a schematic diagram of the sample for measurement of thermal lami distortion. It is a plot of total internal distortion and the dimensional change before and behind etching. It is a schematic diagram which shows the acquisition position of the measurement sample of a heating contraction rate.

  The present invention is a polyimide laminate having a thermoplastic polyimide resin layer on at least one surface of a non-thermoplastic polyimide film, and having a width of 150 mm or more, and heating the laminate in the longitudinal direction at the glass transition temperature of the laminate. The shrinkage factor α and the heat shrinkage factor β in the width direction of the laminate at the glass transition temperature are −2.1 <α <0.1 and −2.5 <β <−0.5, and It is a long polyimide layered product which has become the range of -0.1 <alphax beta <6.0.

  In the polyimide laminate of the present invention, the heat shrinkage ratio α in the longitudinal direction (MD direction) of the film at the glass transition temperature of the polyimide laminate, the heat shrinkage ratio β in the width direction (TD direction) of the laminate, and α-β The absolute value of is within a specific range. As a method of reducing the dimensional change rate conventionally known, from the viewpoint of film production, typically, the coefficient of linear expansion of the film is made as close as possible to that of copper foil to reduce the difference in dimensional change due to heat. There is a way. However, when the inventors examined the dimensional change rate at the time of FPC preparation of various polyimide laminates toward realization of smaller dimensional change when finally processed into FPC, the linear expansion coefficient is the same. However, it was found that the dimensional change was not always the same. That is, it has been found that the linear expansion coefficient alone can not be explained. This is because the dimensional change of the material obtained by laminating the film laminate (size: 120 mm in MD direction × 120 mm in TD direction) as described later with the copper foil and the dimensional change in the MD direction and TD direction There is a difference in the dimensional change in the MD and TD directions of the material obtained by laminating it with a copper foil by rotating it and the correlation coefficient between the dimensional change and the linear expansion coefficient in the experiments conducted by the present inventors. Was confirmed by the fact that Therefore, we aim to realize smaller dimensional changes when finally processed into FPCs, and how do dimensional changes occur in the processes of polyimide material manufacture, FCCL manufacture, and FPC manufacture The analysis was performed to determine if it occurred.

  In many cases, FCCL is manufactured by a method of thermally laminating a wide polyimide film laminate and a metal foil while continuously feeding it out, and thereafter, a wiring is formed by etching to become an FPC. Focusing on the strain released by this etching, it was estimated from both theoretical and experimental sides what strain is accumulated in the polyimide film laminate as it goes through these manufacturing processes. First, a polyimide laminate is subjected to thermal lamination in a state of having a strain frozen at the time of film formation. For example, a thermoplastic polyimide-containing layer is provided on a non-thermoplastic polyimide film, and the film is already subjected to various stresses in the process of obtaining a wide and long laminate, and these become polyimide laminates. It remains as distortion. Although this distortion remains with the metal foil and is laminated by thermal lamination, since thermal lamination is usually performed continuously in many cases, the tension applied to the machine feed direction (longitudinal direction; MD direction) at that time Further, distortion is further accumulated in the polyimide laminate inherent in FCCL due to heat applied at the time of lamination, fixation by a pressure surface at the time of lamination, and the like. If a circuit is formed by etching in this state, it is considered that the dimensional change occurs because the distortion is released by the etching. Considering this, it can be considered that the dimensional change rate also differs in the MD direction and the TD direction because the amount of accumulated strain is different in the MD direction and the TD direction. Therefore, the total strain generated from the production of the polyimide laminate to the production of the FCCL, that is, the total strain inherent in the portion of the polyimide laminate which has become the FCCL, is a key in reducing the dimensional change before and after the etching of the metal layer. I thought it would be.

Therefore, the present inventors, as represented by the following formula (1), the total internal strain remaining in the polyimide laminate in FCCL is a strain accumulated in the laminate in the process of producing the polyimide laminate (hereinafter referred to as It is assumed that it is the sum of distortion (also referred to as film formation distortion) and distortion (hereinafter also referred to as heat lamination distortion) accumulated further by force and heat applied in the process of heat lamination.
Film formation distortion + thermal laminal distortion = total internal distortion remaining in the polyimide laminate in FCCL formula (1)
Then, a polyimide laminate having various film-forming distortions is produced in FCCL using a plurality of thermal laminating conditions, and a large number of data of dimensional change rate is acquired to reduce the dimensional change rate. It was considered statistically whether such a laminate. This will be described more specifically.

  The strain accumulated from the production of the polyimide laminate to the production of the FCCL is the total internal strain remaining in the FCCL and is represented by the formula (1).

  The film-forming distortion employ | adopted the heat contraction rate at the time of heating for 30 minutes at the glass transition temperature of a polyimide laminated body. The cause of the heat shrinkage ratio is the residual strain of the polyimide laminate, and there are two types of residual strain: orientation distortion and freeze distortion. Orientation strain is considered to be near the glass transition temperature, and freezing strain is considered to release strain below the glass transition temperature. Because it is necessary to release both strains in order to estimate these two strains more accurately, measurements heated at the glass transition temperature are important. The heating for 30 minutes is because it is believed that this degree of heating will fully release all distortion. The heat shrinkage was measured in the MD and TD directions of the laminate.

  Next, thermal lami distortion can be determined by the following measurement. A film laminate (size: MD direction 120 mm × TD direction 120 mm) from which residual strain accumulated in the polyimide film laminate has been removed by heating at a glass transition temperature for 30 minutes is prepared, and drilling is performed as shown in FIG. Apply and measure the dimensions of MD1 / MD2 / TD1 / TD2. For example, assuming that the laminating temperature is 360 ° C., the film is laminated at 360 ° C., 0.6 ton, 1 m / min, and then the dimensions of MD1 / MD2 / TD1 / TD2 are measured again, and the dimensional change before and after laminating is determined. It calculates about MD direction (average of MD1 and MD2) and TD direction (average of TD1 and TD2). The thermal lamination strain at 360 ° C. differs depending on the MD direction at 0.05% and the TD direction at 0.35%. In this way, the thermal lami distortion can be considered to be constant if the lamination temperature is determined.

  The present inventors adjusted samples (size: MD direction 120 mm × TD direction 120 mm) of polyimide laminates having various heat shrinkage rates. This is various from the film which produces a laminated body in sheet | leaf, or the film in which a dimensional change rate is not stabilized by a site | part in the laminated body produced continuously, in other words, a long polyimide laminated body unsuitable for manufacture of FCCL. It did by collecting the part. At this time, a heat shrinkage ratio in the MD direction and a heat shrinkage ratio in the TD direction were dare different from each other. By rotating the sample by 90 degrees with respect to the laminating direction, two data sets can be obtained from one sample. These samples were laminated with copper foil to prepare FCCL, and the dimensional change rate after copper foil etching was confirmed. The relationship between the total internal strain remaining in the polyimide laminate in the FCCL and the dimensional change rate after copper foil etching was determined as shown in Table 1 and FIG.

  Then, a good correlation was obtained between the total internal strain and the dimensional change. As a result, when the total internal strain remaining in the polyimide laminate in FCCL is unexpectedly zero, the dimensional change rate after metal layer etching does not necessarily become zero, but the strain within a certain range is I found it better to have it. The reason is not clear, but it is speculated that part of the laminate plastically deforms when the laminate exceeds the glass transition temperature during heat lamination. This is based on a technical idea different from that of Patent Document 2 whose purpose is to reduce the dimensional change rate before and after heating the FPC obtained by the etching. On the other hand, when using a polyimide laminate having a glass transition point, when FCCL is produced by a thermal lamination method, plastic deformation of the copper foil in the MD direction and TD direction contraction and the film following it are subjected to viscoelastic deformation It is preferable that it is a laminated body which has a glass transition point, since it is easy.

  The present inventors first determine the value of total internal strain so as to reduce the dimensional change rate, and then determine the appropriate value of film formation strain for each of the MD direction and the TD direction using Equation (1). The Moreover, the same measurement and analysis were performed about the case where 320 degreeC and 380 degreeC were assumed as lamination temperature. The reason for adding the analysis when the lamination temperature is 320 ° C and 380 ° C is to obtain the total internal strain so as to reduce the dimensional change rate with high accuracy as much as possible, or copper foil type, laminate during FCCL manufacture This is because there is a possibility of changing the laminating temperature by 320 to 380 ° C. depending on the material. As a result of acquiring and analyzing a large number of data to see the correlation between the total internal strain and the rate of dimensional change in this manner, the heat shrinkage rate in the machine feed direction when the polyimide laminate and metal foil are thermally laminated is -2 .1 and less than 0.1, and the heat shrinkage rate in the direction orthogonal to the machine direction is greater than -2.5 and less than -0.5, and (heat shrinkage rate in the machine feed direction) x (cross direction) It was found that the difference in dimensional change rate between the MD direction and the TD direction becomes smaller when the heat shrinkage rate of (1) is greater than -0.1 and not more than 6.0. Industrially, FCCL is manufactured by continuously feeding and laminating a roll-like wide polyimide laminate with a metal foil, so that the heat shrinkage ratio α in the longitudinal direction of the polyimide laminate is at the time of thermal lamination In the machine feed direction, the width direction β is in the orthogonal direction. And polyimide laminates satisfying −2.1 <α <0.1, −2.5 <β <−0.5, and −0.1 <α × β <6.0, respectively. For example, an FPC with a small dimensional change rate can be obtained.

  Thus, as the physical properties of the polyimide laminate that can be controlled to reduce the dimensional change before and after etching of FCCL manufactured by thermal lamination, the heat shrinkage rate can be selected, and the range to be controlled is determined. If it is in the above-mentioned range at least at both ends and the central part of the long polyimide laminate, an FPC having a small dimensional change rate can be industrially obtained. The dimensional change rate is analyzed in each of MD and TD directions from the viewpoint of film formation distortion of polyimide laminate and thermal lamination distortion accumulated during thermal lamination to be crushed, and a method for determining the optimum film formation distortion in each direction is used. It has not been reported so far and has been found based on the above analysis and data by the present inventors.

  The preferred range of α is -0.5% to -2.0%, and more preferably -0.9% to -1.4%. The preferred range of β is −2.3% to −1.1%, more preferably −1.9% to −1.5%. Further, the preferable range of α × β is 0.3 <α × β <3.0. The range of these preferable values and the range of the more preferable values are set based on the above-mentioned data and analysis.

  The glass transition temperature of the polyimide laminate refers to the peak top temperature of the loss coefficient (tan δ) when the dynamic viscoelasticity measurement is performed under the measurement conditions of frequencies of 1 Hz, 5 Hz, 10 Hz, and 3 ° C./min. For measurement of the heat shrinkage rate, samples (size: 12 cm × 12 cm) are obtained from three places shown in FIG. 3, and the dimensions of MD1 / MD2 / TD1 / TD2 are measured. Next, the dimensions of MD1 / MD2 / TD1 / TD2 when heated at the glass transition temperature for 30 minutes are measured again, and the rate of change in each of MD and TD (average of MD1 and MD2 and average of TD1 and TD2) Ask for It is necessary to reduce the dimensional change rate of the FPC using FCCL obtained by continuously performing the thermal lamination that the heat shrinkage ratio falls within the above-mentioned range at three places shown in the figure. These are because they are measurement sites suitable for confirming the characteristics of the entire polyimide laminate.

  The polyimide laminate of the present invention is a long laminate suitable for industrial FCCL production, and has a width of 150 mm or more, preferably 250 mm or more, and more preferably 500 mm or more. The difference between the maximum value and the minimum value of α measured at three locations is preferably 0.10% or less. The difference between the maximum value and the minimum value of β measured at three locations is preferably 0.10% or less. The difference between the maximum value and the minimum value of α-β obtained at three locations is preferably 0.10% or less.

  The polyimide laminate of the present invention has a thermoplastic polyimide resin layer on at least one surface of a non-thermoplastic polyimide film. Therefore, first, the production of the non-thermoplastic polyimide film will be described.

  The diamine used for producing the non-thermoplastic polyimide film is not particularly limited, but at least one type of diamine which is likely to exhibit β relaxation is used since the polyimide finally obtained needs to exhibit β relaxation. It is preferable to do. Because it depends on the structure of acid dianhydride, it is not possible to uniquely determine the diamine expressing β relaxation, but when using a diamine having a biphenyl skeleton and a phenyl skeleton, the obtained polyimide exhibits β relaxation Easy to do. Specifically, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-3,3'-hydroxybiphenyl, 1,4-diaminobenzene, 1,3-diaminobenzene, 4,4'-bis (4-aminophenoxy) biphenyl and the like. In order to control various properties such as mechanical strength, it is also possible to use diamines other than the above as a part of the raw materials, as long as the polyimide finally obtained exhibits β relaxation. Specific examples of the diamine other than the above include 4,4′-diaminodiphenyl ether, 2,2-bis {4- (4-aminophenoxy) phenyl} propane, 1,3-bis (4-aminophenoxy) benzene, 1 And 4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene and the like.

  The acid dianhydride is also not particularly limited, but it is preferable to use at least one acid dianhydride which is apt to develop β relaxation. Although it also depends on the structure of diamine, β acid relaxation is likely to be expressed using acid dianhydride having a biphenyl skeleton and a phenyl skeleton also for acid dianhydride. Specific structures include 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride, pyromellitic acid dianhydride, and the like. With regard to the acid dianhydride, it is possible to use acid dianhydrides other than the above as a part of the raw materials, as long as the polyimide finally obtained exhibits β relaxation. Specifically, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, etc. are mentioned.

  The polyamic acid which is a precursor of polyimide is obtained by mixing and reacting the above diamine and acid dianhydride in an organic solvent so as to be substantially equimolar. As the organic solvent to be used, any solvent can be used as long as it dissolves polyamic acid, but amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like N, N-dimethylformamide and N, N-dimethylacetamide can be particularly preferably used. The solid content concentration of the polyamic acid is not particularly limited, and when it is in the range of 5 to 35% by weight, a polyamic acid having sufficient mechanical strength can be obtained when it is used as a polyimide.

  The order of addition of the raw material diamine and acid dianhydride is not particularly limited, but it is possible to control the properties of the obtained polyimide not only by the chemical structure of the raw material but also by controlling the order of addition.

  In addition, when 1,4-diaminobenzene and pyromellitic dianhydride are used as raw materials, the polyimide structure obtained by combining the two has low durability to a desmear liquid, so the addition order is adjusted and both are directly bonded It is preferable not to form the same structure.

  A filler may be added to the polyamic acid for the purpose of improving various properties of the film such as slidability, thermal conductivity, conductivity, corona resistance, loop stiffness and the like. Any filler may be used, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica and the like.

  In addition, thermosetting resins such as epoxy resin and phenoxy resin, and thermoplastic resins such as polyether ketone and polyether ether ketone may be mixed within a range that does not impair the characteristics of the entire resin layer obtained. As a method of adding these resins, a method of adding to the above polyamic acid as long as it is soluble in a solvent can be mentioned. If the polyimide is also soluble, it may be added to the polyimide solution.

In the present invention, the method for producing the non-thermoplastic polyimide film is
i) reacting an aromatic diamine with an aromatic tetracarboxylic acid dianhydride in an organic solvent to obtain a polyamic acid solution,
ii) casting a film forming dope containing the above polyamic acid solution on a support,
iii) peeling off the gel film from the support after heating on the support;
iv) further heating to imidize the remaining amic acid and drying it;
Is preferred.
In the following steps ii), thermal imidization and chemical imidization are roughly classified. The thermal imidization method is a method in which a polyamic acid solution is used as a film-forming dope to flow to a support without using a dehydrating ring-closing agent or the like, and imidization is promoted only by heating. One chemical imidization method is a method of promoting imidization by using a polyamic acid solution to which a dehydrated ring-closing agent and / or a catalyst is added as a film-forming dope. Either method may be used, but the chemical imidation method is more excellent in productivity.

  As a dehydrating ring-closing agent, an acid anhydride represented by acetic anhydride can be suitably used. As the catalyst, tertiary amines such as aliphatic tertiary amines, aromatic tertiary amines and heterocyclic tertiary amines can be suitably used.

  As a support which casts film forming dope, a glass plate, aluminum foil, an endless stainless steel belt, a stainless steel drum etc. may be used suitably. The heating conditions are set according to the thickness and production rate of the finally obtained sheet, and after partial imidization and / or drying, the support is peeled off to obtain a polyamic acid film (hereinafter referred to as gel film). .

  The end of the gel film is fixed and dried to avoid shrinkage on curing to remove water, residual solvent, residual conversion agent and catalyst, and to fully imidize the remaining amic acid to contain polyimide. Sheet is obtained. The heating conditions may be appropriately set according to the thickness of the sheet finally obtained and the production rate, but the temperature is preferably 350 ° C. to 500 ° C., and the heating time is 15 seconds to 30 seconds. Is preferred.

  The term "non-thermoplastic" refers to a material which is melted when the film is heated to about 450 ° C. to 500 ° C. and retains the shape of the film.

  Next, the thermoplastic polyimide resin used for the thermoplastic polyimide resin layer will be described. The aromatic diamine and the aromatic tetracarboxylic acid dianhydride used for the thermoplastic polyimide resin may be the same as those used for the non-thermoplastic polyimide film, but in order to obtain a thermoplastic polyimide, It is preferable to react a diamine having flexibility with an acid dianhydride. Examples of flexible diamines include 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-bis (3-aminophenoxy) biphenyl, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 2,2-bis (4-aminophenoxyphenyl) ) Examples of propane and acid dianhydride include pyromellitic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid Acid dianhydride, 4,4'- oxydiphthalic acid dianhydride, etc. are mentioned. Thermoplastic means that it has a glass transition temperature and in the thermomechanical analysis (TMA) of the compression mode (probe diameter 3 mmφ, load 5 g) (10 ° C. to 400 ° C. (heating rate: 10 ° C./min) The one that causes permanent compression deformation in the temperature range of In addition, other resin and additive may be contained in the thermoplastic polyimide resin layer as needed. The preferable glass transition temperature of the thermoplastic polyimide resin layer in the present invention is 100 ° C to 300 ° C.

  As a method of providing a thermoplastic polyimide resin layer, a method of applying a thermoplastic polyimide precursor on the non-thermoplastic polyimide film obtained as described above and imidization thereafter, or applying a thermoplastic polyimide solution It includes, but is not limited to, a method of drying. The glass transition temperature of the polyimide laminate is preferably 280 ° C. or more, and more preferably 320 ° C. or more, from the viewpoint of the heat laminating temperature.

  The higher the solvent retention rate of the gel, the higher the adhesion strength between the belt and the gel, which is stretched in the MD direction at the time of gel peeling, shrinks in the TD direction at Poisson's ratio, and shrinks / shrinks in the MD and TD directions respectively. Distortion in the direction of expansion is accumulated. When the tension applied to the gel pulled off from the belt is large, the gel is stretched in the MD direction, and the TD direction shrinks at Poisson's ratio, and strain in the shrinkage / expansion direction is accumulated during heating in the MD and TD directions. The temperature at which heating of the gel begins is also affected. Since the gel contains a solvent and the imidization rate is also low, the higher the heating start temperature, the more volatilization and curing shrinkage of the solvent proceed rapidly, and the heat shrinkage rates in the MD and TD directions increase. In addition, the film temperature decreases toward the heating furnace outlet, and strain accumulates from the point where the temperature is below the glass transition temperature of non-thermoplastic polyimide, so the larger the difference between the maximum temperature of imidization and the temperature at the furnace outlet, the MD direction and The heat shrinkage of TD increases.

  The polyimide film laminate of the present invention thus obtained can be laminated with a metal foil to produce FCCL. The metal foil that can be used in the present invention is not particularly limited, but in the case of using the flexible metal-clad laminate of the present invention for electronic device and electric device applications, for example, copper or copper alloy, stainless steel or the like A foil made of an alloy, nickel or nickel alloy (including 42 alloy), aluminum or aluminum alloy can be mentioned. In general flexible metal-clad laminates, copper foils such as rolled copper foils and electrolytic copper foils are often used, but they can also be preferably used in the present invention.

  In order to bond the metal foil and the polyimide film laminate, for example, a continuous treatment using a heat roll laminating apparatus having a pair or more of metal rolls or a double belt press (DBP) can be used. Among them, the polyimide film laminate of the present invention exhibits a remarkable effect when using a heat roll laminating apparatus having a pair or more of metal rolls.

  Although the specific configuration of the means for carrying out the thermal lamination is not particularly limited, a protective material is disposed between the pressing surface and the metal foil in order to improve the appearance of the resulting laminate. It is preferable to do. As the protective film to be used, any film can be used as long as it can withstand the heating temperature of the thermal laminating process, and heat resistant plastic such as non-thermoplastic polyimide film, metal foil such as copper foil, aluminum foil, SUS foil etc. may be mentioned. Among them, a non-thermoplastic polyimide film can be suitably used, from the viewpoint that the balance of heat resistance, reusability and the like is excellent.

  The heating temperature in the heat lamination step is generally 320 ° C. to 380 ° C. The laminating speed in the heat laminating step is preferably 0.5 m / min or more, and more preferably 1.0 m / min or more. If it is 0.5 m / min or more, sufficient thermal lamination is possible, and if it is 1.0 m / min or more, productivity can be further improved.

  The pressure in the thermal laminating step is preferably in the range of 49 N / cm to 490 N / cm (5 kgf / cm to 50 kgf / cm), and 98 N / cm to 320 N / cm (10 kgf / cm to 30 kgf / cm). It is more preferable to be within the range.

  The tension applied to the laminate during lamination is preferably 0.01 N / cm to 2 N / cm, more preferably 0.02 N / cm to 1.5 N / cm, and particularly preferably 0.05 N / cm to 1.0 N / cm. . If the tension is below this range, it may be difficult to obtain a flexible metal-clad laminate with a good appearance, and if it is above this range, dimensional stability tends to be poor.

  In FCCL using the polyimide film laminate of the present invention, the dimensional change rate after removing the metal foil is 0 ± 0.025% in both the MD direction and the TD direction, and the in-plane variation is σ = It is 0.030%.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

(Method of measuring glass transition temperature)
The loss coefficient (tan δ) was determined by DMS 6100 manufactured by SII Nano Technology, and the temperature at the peak top was taken as the glass transition temperature.
Sample measurement range; width 9 mm, distance between jaws 20 mm
Measurement temperature range: 0 to 440 ° C
Heating rate: 3 ° C / min Strain amplitude: 10μm
Measurement frequency: 1, 5, 10 Hz
Minimum tension / compression force; 100mN
Tension / compression gain; 1.5
Force amplitude initial value: 100 mN
(Method of measuring heat shrinkage of polyimide film laminate)
Take a sample of 120 mm × 120 mm and measure the dimensions of MD1 / MD2 / TD1 / TD2. Next, the dimensions of MD1 / MD2 / TD1 / TD2 when heated at glass transition temperature × 30 minutes were measured again, and the change rates in each of the MD direction and the TD direction were determined.

(Measurement method of dimensional change rate)
A 12 μm electrolytic copper foil (3EC-M3S-HTE (K)) is placed on both sides of a long (255 mm wide) polyimide laminate, and protective materials (Apical 125 NPI: Kaneka) are placed on both sides, The heat lamination was performed using a machine under conditions of a lamination temperature of 360 ° C., a lamination pressure of 0.6 tons, and a lamination speed of 1.0 m / min to prepare a double-sided copper-clad board (FCCL). The obtained FCCL was cut into a size of 120 mm × 120 mm, holes of 1.0 mmφ in diameter were made at intervals of 80 mm at four corners of the FCCL, and the distance between the centers of the circles was measured before and after etching the entire copper surface. The dimensional change was measured using a CNC image processing measurement system under conditions of a temperature of 25 ° C. and a humidity of 60%. The distance before etching MD1 / TD1 and the distance after etching were MD2 / TD2, and the dimensional change was calculated by the following equation.
Dimensional change rate MD (%) = [(MD2-MD1) / MD1] × 100
Dimensional change rate TD (%) = [(TD2-TD1) / TD1] × 100
In addition, before measurement of the distance after copper etching, the sample was left for 90 minutes under conditions of temperature 25 ° C. and humidity 60% to eliminate the influence of water absorption of the polyimide. The dimensional change rate was obtained by averaging the values obtained by measuring three sheets in each of the MD direction and the TD direction.

<Relationship between total internal strain and dimensional change of polyimide laminate>
(Sample preparation of polyimide laminate)
(Film number 1)
From a polyimide laminate having a width of 1600 mm and a length of 1000 m, a sample having a size of 120 mm × 120 mm was cut out from a position 1740 mm from the end of the film.

(Film number 2, 3, 4)
From the polyimide laminate having a width of 1600 mm and a length of 2000 m, three samples with a size of 120 mm × 120 mm (film numbers 2, 3 and 4, respectively) were obtained according to the position of FIG.

(Film numbers 5, 6, 7, 8, 9, 10)
Three samples (film numbers 5, 6, and 7) of 120 mm × 120 mm were obtained from the site of 10 m from the feeding of the polyimide laminate having a width of 1,600 mm and a length of 3,000 m according to the position of FIG. Further, three samples of 120 mm × 120 mm in size were obtained (film numbers 8, 9 and 10, respectively) according to the position shown in FIG.

(Film numbers 11, 12, 13)
Three samples of 120 mm × 120 mm in size were obtained (film numbers 11, 12 and 13 respectively) according to the position of FIG. 3 from a site of 10 m from the feeding of a polyimide laminate having a width of 1600 mm and a length of 3000 m.

(Measurement of heat shrinkage rate of polyimide film laminate)
About all the obtained samples (film numbers 1 to 13) of 120 mm × 120 mm size, the heat shrinkage was measured by the method described in (Measuring method of heat shrinkage of polyimide film laminate).

(Measurement method of dimensional change rate)
The film MD direction of film No. 1 (film size 120 mm × 120 mm) is set in the machine feed direction of the heat roll laminate, and heat is applied at a lamination temperature of 320 ° C., a lamination pressure of 0.6 tons, and a lamination speed of 1.0 m / min. It laminated and produced the double-sided copper-clad board (FCCL) (copper foil: 3EC-M3S-HTE (K), 12 micrometers). FCCL was prepared in the same manner as described above, with laminating temperatures set to 360 ° C. and 380 ° C. Holes with a diameter of 1 mm were made at intervals of 80 mm at four corners of the obtained FCCL, and the distance between the centers of the circles was measured before and after etching the entire copper surface. The dimensional change was measured using a CNC image processing measurement system under conditions of a temperature of 25 ° C. and a humidity of 60%. The distance before etching MD1 / TD1 and the distance after etching were MD2 / TD2, and the dimensional change was calculated by the following equation.
Dimensional change rate MD (%) = [(MD2-MD1) / MD1] × 100
Dimensional change rate TD (%) = [(TD2-TD1) / TD1] × 100
In addition, before measurement of the distance after copper etching, the sample was left for 90 minutes under conditions of temperature 25 ° C. and humidity 60% to eliminate the influence of water absorption of the polyimide. The dimensional change rate was obtained by averaging the values obtained by measuring three sheets each of MD and TD.

The film TD direction of film No. 1 (film size 120 mm × 120 mm) is set in the machine feed direction of the heat roll laminate, and heat is applied at a lamination temperature of 320 ° C., a lamination pressure of 0.6 tons, and a lamination speed of 1.0 m / min. It laminated and produced the double-sided copper-clad board (FCCL) (copper foil: 3EC-M3S-HTE (K), 12 micrometers). FCCL was prepared in the same manner as described above, with laminating temperatures set to 360 ° C. and 380 ° C. Holes with a diameter of 1 mm were made at intervals of 80 mm at four corners of the obtained FCCL, and the distance between the centers of the circles was measured before and after etching the entire copper surface. The dimensional change was measured using a CNC image processing measurement system under conditions of a temperature of 25 ° C. and a humidity of 60%. The distance before etching MD1 / TD1 and the distance after etching were MD2 / TD2, and the dimensional change was calculated by the following equation.
Dimensional change rate MD (%) = [(MD2-MD1) / MD1] × 100
Dimensional change rate TD (%) = [(TD2-TD1) / TD1] × 100
In addition, before measurement of the distance after copper etching, the sample was left for 90 minutes under conditions of temperature 25 ° C. and humidity 60% to eliminate the influence of water absorption of the polyimide. The dimensional change rate was obtained by averaging the values obtained by measuring three sheets in each of the MD direction and the TD direction.

The film MD direction of film numbers 2 to 13 (film size 120 mm × 120 mm) is set in the machine feed direction of the heat roll laminate, and the conditions of laminating temperature 360 ° C., laminating pressure 0.6 tons, laminating speed 1.0 m / min. The heat lamination was performed by this, and the double-sided copper clad board (FCCL) was produced (copper foil: 3EC-M3S-HTE (K), 12 micrometers). Holes with a diameter of 1 mm were made at intervals of 80 mm at four corners of the obtained FCCL, and the distance between the centers of the circles was measured before and after etching the entire copper surface. The dimensional change was measured using a CNC image processing measurement system under conditions of a temperature of 25 ° C. and a humidity of 60%. The distance before etching MD1 / TD1 and the distance after etching were MD2 / TD2, and the dimensional change was calculated by the following equation.
Dimensional change rate MD (%) = [(MD2-MD1) / MD1] × 100
Dimensional change rate TD (%) = [(TD2-TD1) / TD1] × 100
In addition, before measurement of the distance after copper etching, the sample was left for 90 minutes under conditions of temperature 25 ° C. and humidity 60% to eliminate the influence of water absorption of the polyimide. The dimensional change rate was obtained by averaging the values obtained by measuring three sheets each of MD and TD.

The film TD direction of film numbers 2 to 13 (film size 120 mm × 120 mm) is set in the machine feed direction of the heat roll laminate, and the conditions of laminating temperature 360 ° C., laminating pressure 0.6 tons, laminating speed 1.0 m / min. The heat lamination was performed by this, and the double-sided copper clad board (FCCL) was produced (copper foil: 3EC-M3S-HTE (K), 12 micrometers). Holes with a diameter of 1 mm were made at intervals of 80 mm at four corners of the obtained FCCL, and the distance between the centers of the circles was measured before and after etching the entire copper surface. The dimensional change was measured using a CNC image processing measurement system under conditions of a temperature of 25 ° C. and a humidity of 60%. The distance before etching MD1 / TD1 and the distance after etching were MD2 / TD2, and the dimensional change was calculated by the following equation.
Dimensional change rate MD (%) = [(MD2-MD1) / MD1] × 100
Dimensional change rate TD (%) = [(TD2-TD1) / TD1] × 100
In addition, before measurement of the distance after copper etching, the sample was left for 90 minutes under conditions of temperature 25 ° C. and humidity 60% to eliminate the influence of water absorption of the polyimide. The dimensional change rate was obtained by averaging the values obtained by measuring three sheets in each of the MD direction and the TD direction.

(Measurement of thermal lami distortion)
The residual strain was measured as follows for all the samples after measurement of the heat shrinkage of the polyimide film laminate (the samples after heating at the glass transition temperature for 30 minutes to remove the film formation distortion). Prepare a sample, perform drilling as shown in FIG. 1, and measure the dimensions of MD1 / MD2 / TD1 / TD2. The film was laminated with copper foil (3EC-M3S-HTE (K), 12 μm manufactured by Mitsui Mining & Smelting Co., Ltd.) under the conditions of 360 ° C., 0.6 ton, 1 m / min, and then the film was again subjected to MD1 / MD2 / TD1 / TD2 The dimensions are measured, and the percent dimensional change before and after lamination is determined for the MD direction (average of MD1 and MD2) and the TD direction (average of TD1 and TD2). This was taken as a heat laminant distortion at a lamination temperature of 360 ° C. Similarly, when the lamination temperature was 320 ° C., the thermal lami distortion was also measured when the lamination temperature was 380 ° C.

(Calculation of thermal lami distortion)
The following theoretical calculation was performed to confirm that the measured actual measurement value of thermal lami distortion can be relied on as a value corresponding to the amount of distortion further accumulated in the polyimide laminate by thermal lamination.
The strain in the case of heat lamination using a copper foil having a width of 270 mm, a thickness of 12 μm, a tensile elastic modulus of 120 GPa, an elastic limit of 0.01% and a CTE (100 ° C. to 200 ° C.) 18 ppm is calculated. At this time, the tension of the copper foil in the MD direction is 50 kgf (490 N), and it is assumed that the heat roll temperature is 360 ° C., the temperature before the heat roll pressure zone is 50 ° C., and the Poisson's ratio of the polyimide film laminate is 0.3. In this case, the strain in the MD direction accumulated during lamination can be calculated as follows. First, the tensile stress in the MD direction is 490 N / (270 mm × 0.12) ≒ 151 Mpa. 490 N was chosen because it is empirically known that it is a tension that can make a good-looking FCCL. Next, the elongation in the MD direction is determined as 151 MPa / 120,000 MPa ≒ 0.0013 (0.13%). At this time, since the elastic limit of the copper foil is 0.10%, the actual elongation of the copper foil is 0.13% −0.10% = 0.03%. It is expressed as +0.03 because it is contraction due to elongation. Although this becomes distortion accumulated in the polyimide film laminated body which follows copper foil, this corresponds with the said actual value well. In the MD direction, since the elastic modulus is assumed to be constant due to temperature, thermal expansion is ignored.

On the other hand, distortion accumulated in the TD direction can be calculated as follows. In the TD direction, thermal expansion tends to occur during thermal lamination, but distortion occurs because the dimensions in the width direction are fixed by the laminating apparatus. That is, TD direction shrinkage = copper foil temperature rise width in heat roll pressure zone × linear expansion coefficient of copper foil = (360 ° C. (laminate temperature) 50 ° C. (temperature just before entering the roll)) × 18 × 10 ⁻⁶ Actual compression in the TD direction = 0.5% −0.1% (elastic limit) = 0.4% at 0.005 (0.5%).

  Further, the shrinkage in the TD direction is a portion which is compressed in the TD direction by being stretched in the MD direction, and this can be calculated by an elongation in the MD direction x Poisson's ratio. Therefore, it is 0.03% (elongation in the MD direction) × 0.3 = 0.009%. From the above, it can be calculated that the total shrinkage in the TD direction = 0.4% + 0.009% ≒ 0.4%, and since it is the distortion as a result of shrinkage in the TD direction, the expression of −0.4 matches well with the above-mentioned measured value .

(Measurement of dimensional change rate after copper foil etching)
The dimensions of MD1 / MD2 / TD1 / TD2 of the sample for which the thermal roll distortion was measured were measured according to the method described in (Method of measuring dimensional change). However, it differs in that a sheet-like sample is used instead of a continuous laminate. Then, the copper foil was removed by etching, and the dimensions of MD1 / MD2 / TD1 / TD2 were measured again.

(Relationship between total internal strain and dimensional change)
Using the film formation distortion and thermal lamination distortion of the polyimide laminate, the heat shrinkage ratio of the sample determined as described above was expressed by the following equation (1)
Film formation strain + thermal laminage strain = total internal strain (1) remaining in the polyimide laminate in FCCL The total internal strain was determined, and the relationship between this and the dimensional change was summarized in Table 1. From this result, assuming that the dimensional change rate after copper foil etching is y and the total internal strain is x, the following relational expression is obtained.
320 ° C y = -0.0781 x + 0.046 (2)
360 ° C. y = −0.031x + 0.0456 (3)
380 ° C. y = −0.0447x + 0.0086 (4)
Next, the dimensional change rate after etching measured by laminating on a single wafer was converted to the dimensional change rate after etching measured by laminating on a long sheet (Table 2). In general, the dimensional change is different between the case of laminating with a long strip and the case of laminating with a single leaf. That is because, in the case of long-length lamination, there are effects such as tension applied to the film at the time of lamination. Assuming that the same film is laminated on a sheet-by-sheet basis and in a long sheet, and the dimensional change rates after etching are y and z, the relationships of formulas (5) and (6) can be confirmed.
MDz = 0.9261 x y + 0.0323 (5)
TDz = 0.5176 × y + 0.0337 (6)
From the relationship of (5) and (6), the relationship between the dimensional change ratio z and the total internal strain x in the case of laminating with a length after copper foil etching was obtained from the relationships of (2) (3) (4). The values of dimensional change rate z and total internal strain x are plotted in FIG.
320 ° C z = -0.485x + 0.0597 (7)
360 ° C. z = −0.0319x + 0.0383 (8)
380 ° C. z = −0.0323x + 0.0366 (9)
At each temperature, a range of total internal strain such that the dimensional change rate z after etching was reduced was first determined. From the preferred total internal strain, apply equation (1) to the MD and TD directions respectively,
Film-forming strain in MD direction + heat laminant strain in MD direction = preferred total internal strain (10)
Film formation strain in the TD direction + thermal lamination strain in the TD direction = preferred total internal strain (11)
From the relational expression, the film formation distortion in the MD direction and the film formation distortion in the TD direction, which the polyimide laminate should have at each lamination temperature, are determined in order to reduce the dimensional change rate. From these results, the heat shrinkage of a polyimide film laminate was determined so as to be an FPC with a small dimensional change even when FCCL was manufactured at a commonly used laminating temperature.

  Lamination temperature (° C) of each film, film formation strain (heat shrinkage ratio α (%), thermal lami strain β (%), total internal strain (strain α + β (%) accumulated after copper foil lamination, copper foil after etching The dimensional change rates (%) of are shown in Tables 1 to 4 in Table 1, 5 to 10 in Table 2, and 11 to 13 in Table 3.

Example 1
46.43 g of 2,2-bis (4-aminophenoxyphenyl) propane (BAPP) was dissolved in 546 g of N, N-dimethylformamide (DMF) cooled to 10 ° C. After 9.12 g of 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) was added and dissolved in it, 16.06 g of pyromellitic dianhydride (PMDA) was added for 30 minutes. Stir to form a thermoplastic polyimide precursor block component.
After 18.37 g of p-phenylenediamine (p-PDA) was dissolved in this solution, 37.67 g of PMDA was added and dissolved by stirring for 1 hour. Furthermore, a DMF solution (PMDA 1.85 g / DMF 24.6 g) prepared separately was carefully added to this solution, and the addition was stopped when the viscosity reached about 3000 poise. The mixture was stirred for 1 hour to obtain a polyamic acid solution having a solid concentration of about 19% by weight and a rotational viscosity of 3400 poise at 23 ° C.

  An imidation accelerator consisting of acetic anhydride / isoquinoline / DMF (weight ratio 2.0 / 0.3 / 4.0) is added to this polyamic acid solution at a weight ratio of 45% with respect to the polyamic acid solution, continuously The mixture was stirred by a mixer, extruded from a T-die, and cast on a stainless steel endless belt running under 20 mm of the die. After heating this resin film at 130 ° C for 100 seconds, peel off the self-supporting gel film from the endless belt (30% by weight of volatile matter content), fix it on a tenter clip, convey it to the heating furnace and dry at 250 ° C. The film was continuously dried and imidated for 30 seconds in a furnace, in a hot air drying oven at 400 ° C. for 30 seconds, and in an IR furnace at 500 ° C. for 30 seconds, to obtain a polyimide film having a thickness of 17.0 μm.

(Synthesis of Thermoplastic Polyimide Precursor)
29.8 g of BAPP was dissolved in 249 g of DMF cooled to 10 ° C. After 21.4 g of BPDA was added thereto and dissolved, it was stirred for 30 minutes to form a prepolymer. Furthermore, a DMF solution (BAPP 1.57 g / DMF 31.4 g) of BAPP prepared separately was carefully added to this solution, and the addition was stopped when the viscosity reached about 1000 poise. The mixture was stirred for 1 hour to obtain a polyamic acid solution having a solid concentration of about 17% by weight and a rotational viscosity of 1000 poise at 23 ° C.

(Preparation of polyimide laminate)
After diluting the thermoplastic polyamic acid solution with DMF to a solid concentration of 10% by weight, apply a polyamic acid with a comma coater on one side of the non-thermoplastic polyimide film (17.0 μm) so that the final single side thickness becomes 4 μm. The heating was performed by passing through a drying oven set at 140 ° C. for 1 minute. The other side was similarly coated with a polyamic acid so that the final thickness would be 4 μm, and then heating was performed by passing through a drying oven set at 140 ° C. for 1 minute. Subsequently, heating imidization was performed by passing through a far infrared heater furnace having an atmosphere temperature of 360 ° C. for 20 seconds to obtain a polyimide film laminate having a total thickness of 25.0 μm. The heat shrinkage and dimensional change of the obtained film were measured. The heat shrinkage rate was sampled from three places shown in FIG. The results are shown in Table 4.

(Example 2)
46.43 g of 2,2-bis (4-aminophenoxyphenyl) propane (BAPP) was dissolved in 546 g of N, N-dimethylformamide (DMF) cooled to 10 ° C. After 9.12 g of 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) was added and dissolved in it, 16.06 g of pyromellitic dianhydride (PMDA) was added for 30 minutes. Stir to form a thermoplastic polyimide precursor block component.
After 18.37 g of p-phenylenediamine (p-PDA) was dissolved in this solution, 37.67 g of PMDA was added and dissolved by stirring for 1 hour. Furthermore, a DMF solution (PMDA 1.85 g / DMF 24.6 g) prepared separately was carefully added to this solution, and the addition was stopped when the viscosity reached about 3000 poise. The mixture was stirred for 1 hour to obtain a polyamic acid solution having a solid concentration of about 19% by weight and a rotational viscosity of 3400 poise at 23 ° C.

  An imidation accelerator consisting of acetic anhydride / isoquinoline / DMF (weight ratio 2.0 / 0.3 / 4.0) is added to this polyamic acid solution at a weight ratio of 45% with respect to the polyamic acid solution, continuously The mixture was stirred by a mixer, extruded from a T-die, and cast on a stainless steel endless belt running under 20 mm of the die. After heating this resin film at 130 ° C for 100 seconds, peel off the self-supporting gel film from the endless belt (volatile content 45% by weight), fix it on a tenter clip, convey it to the heating furnace, and dry at 350 ° C. The film was continuously dried and imidated for 30 seconds in a furnace, in a hot air drying oven at 400 ° C. for 30 seconds, and in an IR furnace at 500 ° C. for 30 seconds, to obtain a polyimide film having a thickness of 17.0 μm.

  A thermoplastic polyimide precursor was applied to both surfaces in the same manner as in Example 1, dried, and imidized to prepare a polyimide laminate. The heat shrinkage and dimensional change of the obtained film were measured. The heat shrinkage rate was sampled from three places shown in FIG. The results are shown in Table 4.

(Comparative example 1)
46.43 g of 2,2-bis (4-aminophenoxyphenyl) propane (BAPP) was dissolved in 546 g of N, N-dimethylformamide (DMF) cooled to 10 ° C. After 9.12 g of 3,3 ', 4,4'-benzophenonetetracarboxylic acid dianhydride (BTDA) was added and dissolved in it, 16.06 g of pyromellitic dianhydride (PMDA) was added for 30 minutes. Stir to form a thermoplastic polyimide precursor block component.
After 18.37 g of p-phenylenediamine (p-PDA) was dissolved in this solution, 37.67 g of PMDA was added and dissolved by stirring for 1 hour. Furthermore, a DMF solution (PMDA 1.85 g / DMF 24.6 g) prepared separately was carefully added to this solution, and the addition was stopped when the viscosity reached about 3000 poise. The mixture was stirred for 1 hour to obtain a polyamic acid solution having a solid concentration of about 19% by weight and a rotational viscosity of 3400 poise at 23 ° C.

  An imidation accelerator consisting of acetic anhydride / isoquinoline / DMF (weight ratio 2.0 / 0.3 / 4.0) is added to this polyamic acid solution at a weight ratio of 45% with respect to the polyamic acid solution, continuously The mixture was stirred by a mixer, extruded from a T-die, and cast on a stainless steel endless belt running under 20 mm of the die. After heating this resin film at 130 ° C for 100 seconds, peel off the self-supporting gel film from the endless belt (volatile content 60% by weight), fix it on a tenter clip, convey it to the heating furnace and dry it at 300 ° C. The film was continuously dried and imidated for 30 seconds in a furnace, in a hot air drying oven at 400 ° C. for 30 seconds, and in an IR furnace at 500 ° C. for 30 seconds, to obtain a polyimide film having a thickness of 17.0 μm.

  A thermoplastic polyimide precursor was applied to both surfaces in the same manner as in Example 1, dried, and imidized to prepare a polyimide laminate. The heat shrinkage and dimensional change of the obtained film were measured. The heat shrinkage and dimensional change of the obtained film were measured. The heat shrinkage rate was sampled from three places shown in FIG. The results are shown in Table 4.

Claims (3)

  A polyimide laminate having a thermoplastic polyimide resin layer on at least one surface of a non-thermoplastic polyimide film, wherein the laminate has a glass transition point, a width of 150 mm or more, and the glass transition temperature of the laminate. Assuming that the heat shrinkage ratio α in the longitudinal direction of the film and the heat shrinkage ratio β in the width direction of the film at the glass transition temperature are: −2.1 <α <0.1, −2.5 <β <−0.5 A polyimide laminate characterized by being present and in the range of −0.1 <α × β <6.0.   The glass transition temperature of the said polyimide laminated body is 100-300 degreeC, The polyimide laminated body of Claim 1 characterized by the above-mentioned.   The polyimide laminate is obtained by applying and drying a solution containing at least one of a thermoplastic polyimide precursor and a thermoplastic polyimide on at least one surface of a non-thermoplastic polyimide film. The manufacturing method of the polyimide laminated body as described in claim 1 or 2.