JP4785340B2 - Polyimide metal laminate - Google Patents

Description

  The present invention relates to a polyimide metal laminate widely used for flexible wiring boards and the like.

  In recent years, with the downsizing and portability of electronic devices, the use of polyimide metal laminates capable of high-density mounting of components and elements as circuit board materials is increasing. In order to cope with higher density, a polyimide metal laminated board suitable for processing a fine pattern having a wiring width of 10 to 50 μm is desired, and components and elements are mounted on such fine processing and fine processing. In some cases, there is an increasing demand for a small amount of external warping.

  For example, as described in Non-Patent Document 1, a method for reducing the warpage has been studied. For example, as shown in Non-Patent Document 1, a polyimide precursor having a linear expansion coefficient of 18 and 22.4 ppm / ° C. is approximately equal to that of the copper foil. It is shown that a polyimide metal laminate obtained by applying and drying a polyamic acid as a body is a substantially flat plate. However, the method of applying and drying polyamic acid on the copper foil has a problem that the time required for drying becomes extremely long when the thickness of the polyimide layer is increased.

  Therefore, there is a method in which a polyimide film having a wide thickness range is bonded to a metal foil. For example, Patent Document 1 discloses that a polyimide metal laminate obtained by applying an adhesive to a polyimide film having a linear expansion coefficient of 15 to 16 ppm / ° C. and a thickness of 50 μm and laminating with a copper foil is a substantially flat plate. It is disclosed. However, this method uses an adhesive that is inferior in heat resistance and insulation, so it is used for recent wiring board applications using lead-free solder that requires high temperatures and fine pattern applications that require high insulation characteristics. There are cases where it is not possible.

  On the other hand, as a method that does not use an adhesive, a production method is known in which a metal is formed on a polyimide film by vacuum deposition or sputtering. For example, as disclosed in Patent Document 2, a polyimide metal laminated plate or the like obtained by a method in which a base metal is formed on a polyimide film by a sputtering method and then a copper layer is formed by plating, and these are substantially flat plates. The reason seems to be that a high temperature is not required in the production process and that there is almost no warpage resulting from the difference in coefficient of linear expansion between copper and polyimide. However, this method requires not only special equipment such as vacuum deposition and sputtering, but also the electrical resistance of the base metal layer before plating is large, and plating defects called pinholes are likely to occur during copper plating, resulting in poor conduction. There is a fatal problem that has not yet been resolved.

Therefore, a method is known in which a copper foil and a non-thermoplastic polyimide film are bonded together using a heat-resistant thermoplastic polyimide as an adhesive. For example, Patent Document 3 discloses a polyimide metal laminate obtained by thermocompression bonding a polyimide film and a copper foil with thermoplastic polyimide. However, as shown in the prior art, when the polyimide film to be used is in the range of 15 to 22.4 ppm / ° C., which is expected to have no warpage, the warpage of the polyimide metal laminate is substantially flat. Even so, the warp after the metal layer was removed by etching was large, and a new problem that warp anisotropy occurred in MD and TD occurred. As described above, the warpage of the polyimide metal laminate is considered to occur due to the difference in linear expansion coefficient between the metal layer and the polyimide layer, but the warpage when the metal is removed cannot be explained. Moreover, since the metal layer becomes a circuit and most of the metal is removed, the shape after the metal layer of the polyimide metal laminate is removed is the most important in the final form of the polyimide metal laminate usually used. However, a satisfactory product could not be obtained by the conventional method.
"Journal of Applied Polymer Science" Vol.51, pp. 1647-1653 Japanese Patent No. 3356560 Japanese Patent Laid-Open No. 6-23634 Japanese Unexamined Patent Publication No. 7-193349

  The problem to be solved by the present invention is that the polyimide metal laminate and the polyimide alone after removing the metal are small in warpage, and there is no anisotropy in MD and TD. Furthermore, in heat resistance and fine workability It is to provide an excellent polyimide metal laminate efficiently.

  As a result of intensive studies to solve the above-mentioned problems, the present applicant has found that a linear expansion of TD and MD of a non-thermoplastic polyimide film in a polyimide / metal laminate including at least one non-thermoplastic polyimide film layer. The inventors have found that the above problem can be solved by using an absolute value of the coefficient difference within a specific value, and have reached the present invention.

That is, the present invention relates to the following.
(1) A polyimide and metal laminate including at least one non-thermoplastic polyimide film layer, the width direction of the non-thermoplastic polyimide film layer (hereinafter sometimes referred to as TD) and the length direction ( The polyimide metal laminate is characterized in that the absolute value of the difference in average linear expansion coefficient at 100 ° C. to 200 ° C. is sometimes 0 ppm / ° C. or more and 6 ppm / ° C. or less.
(2) The polyimide metal laminate according to (1), wherein the non-thermoplastic polyimide film layer has an average linear expansion coefficient at 250 ° C. to 350 ° C. of −20 ppm / ° C. to 1000 ppm / ° C.
(3) When a measurement sample with a polyimide metal laminate plate of 35 mm in MD and TD and a strip of 2 mm in length is left at 23 ° C, 50% RH, 24 hr or longer, the warpage of both MD and TD is 3 mm or less. The polyimide metal laminate is characterized in that the warpage of the entire polyimide layer after removing the metal by etching is 3 mm or less for both MD and TD under the same conditions.

  According to the present invention, the obtained polyimide metal laminate can efficiently provide a polyimide metal laminate having a substantially flat warp of the entire polyimide layer after removing the metal and having no anisotropy in MD and TD. The polyimide metal laminate is excellent in heat resistance because it is made of polyimide that does not use an epoxy or acrylic adhesive, and is excellent in fine workability by using a metal foil having no pinhole.

Hereinafter, the present invention will be described in detail.
The polyimide metal laminate of the present invention is a polyimide and metal laminate including at least one non-thermoplastic polyimide film layer, and the width direction of the non-thermoplastic polyimide film (hereinafter sometimes referred to as TD) and The absolute value of the linear expansion coefficient difference in the length direction (hereinafter sometimes referred to as MD) at 100 ° C. to 200 ° C. needs to be 0 ppm / ° C. or more and 6 ppm / ° C. or less, preferably 0 ppm / More than 5 ° C / ° C. If it is in this range, the anisotropy of warping hardly occurs.

  Here, regarding the method of measuring the linear expansion coefficient in the width direction and the length direction, a non-thermoplastic polyimide having a width of about 4 mm and a length of about 20 mm is used using TMA-4000 manufactured by McScience (currently Bruker XS). After measuring the amount of expansion and contraction of the film in an air atmosphere, a load of 0.049 N, and a temperature increase rate of 10 ° C./min, average linear expansion coefficients of 100 to 200 ° C. and 250 to 350 ° C. were calculated, respectively.

  Furthermore, the average linear expansion coefficient of 250 ° C. to 350 ° C. of the non-thermoplastic polyimide film layer is −20 to 1000 ppm / ° C., preferably −15 to 500 ppm / ° C., more preferably −10 to 100 ppm / ° C. It is preferable to reduce the warp when the metal layer is removed. If it is less than −20 ppm / ° C., the strain remaining inside the polyimide is large and warping is likely to occur due to heating, and if non-thermoplastic polyimide exceeding 1000 ppm / ° C. is used, it may be deformed by heat when mounting elements or components. It is not preferable.

  The polyimide layer in contact with the metal is preferably a thermoplastic polyimide in terms of adhesion, and is not particularly limited as long as its glass transition temperature (Tg) is about 150 to 350 ° C.

  The thickness of the thermoplastic polyimide is preferably 0.1 μm or more and 10 μm or less, more preferably 0.1 or more and 5 μm or less, and still more preferably 0.1 or more and 3 μm or less.

  In the polyimide metal laminate of the present invention, the non-thermoplastic polyimide film layer includes a diamine containing phenylenediamine and / or diaminodiphenyl ether, an acid dianhydride being biphenyltetracarboxylic dianhydride and / or benzophenonetetracarboxylic acid. It is preferable that it is a polyimide manufactured from what contains a dianhydride and / or pyromellitic dianhydride.

  The thickness of the non-thermoplastic polyimide film layer is preferably 3 μm to 250 μm, more preferably 5 μm to 100 μm, and still more preferably 10 μm to 50 μm.

  The non-thermoplastic polyimide and thermoplastic polyimide of the present invention can be used as long as they do not impair the purpose of the present invention, such as other compounds and resins such as maleimide compounds, polyethylene, polypropylene, polycarbonate, polyarylate, polyamide, polysulfone, polyethersulfone, poly An appropriate amount of ether ketone, polyether ether ketone, polyphenyl sulfide, modified polyphenylene oxide, polyamide imide, polyether imide, epoxy resin, or the like can be blended.

  In the polyimide metal laminate of the present invention, the non-thermoplastic polyimide film can be produced by a known technique, and the method is not particularly limited. For example, a polyamic acid and / or a polyimide solution is used as a base material (glass plate). , A metal plate or a heat-resistant resin film), and then peeled off from the substrate and heated. In order to accelerate the reaction, a known dehydrating agent or ring-closing agent may be used. In particular, in order to minimize the residual stress that causes structural changes such as reaction, volume shrinkage, and orientation and crystallization in the imidization and drying process, and to make it uniform in the film, It is desirable to uniformly manage the drying temperature and the tension during transportation.

  Moreover, it is also preferable to heat anneal for the purpose of removing the residual stress of the finished film. As a heating device, a normal heating furnace, an autoclave, or the like can be used. As a heating atmosphere, air, inert gas (nitrogen, argon), or the like can be used. As the heating method, either a method of continuously heating a film or a method of leaving the film in a heating furnace while being wound around a core is preferable. As the heating method, a conductive heating method, a radiant heating method, a combination method thereof, and the like are preferable. The heating temperature is preferably in the temperature range of 200 to 600 ° C. The heating time is preferably in the time range of 0.05 to 5000 minutes.

  The type of metal used in the present invention is not particularly limited, and examples thereof include copper and copper alloys, stainless steel and alloys thereof, nickel and nickel alloys (including 42 alloys), aluminum and aluminum alloys, and the like. Copper and copper alloy are preferable. Moreover, what formed the antirust layer, the heat-resistant layer (for example, plating processing of chromium, zinc, etc.), a silane coupling agent, etc. on these metal surfaces can also be utilized. Preferably, copper and / or nickel, zinc, iron, chromium, cobalt, molybdenum, tungsten, vanadium, beryllium, titanium, tin, manganese, aluminum, phosphorus, silicon, etc. and at least one component and copper are included. These are copper alloys, which are preferred for use in circuit processing. A particularly desirable metal foil is a copper foil formed by rolling or electrolytic plating, and its preferred thickness is 3 to 150 μm, more preferably 3 to 35 μm, and more preferably 3 to 12 μm.

  Even if the metal foil is not subjected to any roughening treatment on both sides, it may be subjected to roughening treatment on one side or both sides, but preferably a low-roughness or non-roughening treatment foil is preferred. Specific examples of commercial products that can be used include F1-WS, F0-WS (trade name, manufactured by Furukawa Circuit Foil), BHY, NK120 (trade name, manufactured by Japan Energy), SLP, USLP (manufactured by Nippon Electrolytic Co., Ltd.) Product name), TQ-VLP, SQ-VLP, FQ-VLP (trade name, manufactured by Mitsui Kinzoku Mining Co., Ltd.), C7025, B52 (trade name, manufactured by Olin), and the like.

  Non-thermoplastic polyimide and metal can be thermocompression-bonded by applying a polyamic acid and / or polyimide solution of a thermoplastic polyimide precursor to a non-thermoplastic polyimide film and drying it, or pasting it on the metal in advance. After forming the plastic polyimide by the same method, there is a method of pasting with a non-thermoplastic polyimide film, and a hot press method and / or a continuous laminating method can be used for the pasting. As the hot press method, for example, the metal foil cut into a predetermined size of a press machine and polyimide can be superposed and thermocompression bonded by a hot press.

  Although there is no restriction | limiting in particular as a continuous laminating method, For example, there exists the method of pinching and sticking between rolls. As this roll, a metal roll, a rubber roll or the like can be used. Although there is no restriction | limiting in a material, Steel materials and stainless steel material are used as a metal roll. It is preferable to use a processing roll with increased surface hardness such as hard chrome plating or tungsten carbide on the surface. As the rubber roll, it is preferable to use heat-resistant silicon rubber or fluorine-based rubber on the surface of the metal roll.

  In addition, two upper and lower metal rolls, called belt laminate, are combined into one set, and two or more seamless stainless steel belts are placed between the upper and lower rolls arranged in series. Pressurization and further laminating may be performed by heating with a metal roll or other heat source.

As the laminating temperature, a temperature range of 200 to 400 ° C. is preferable. As a preferable heating method, a radiation heating method such as far infrared, an induction heating method, and the like can be used in addition to the conductive heating method.
It is also preferable to perform the heat annealing described above after the hot pressing method and / or continuous lamination.

  As a coating method, a polyamic acid / polyimide composition solution (hereinafter collectively referred to as varnish) can be directly applied and dried. In consideration of workability, the content of polyamic acid / polyimide in the varnish is preferably 5 to 70% by weight. The viscosity at 25 ° C. is preferably 1 to 100,000 cps.

  As a method for coating, a known method such as a die coater, a comma coater, a roll coater, a gravure coater, a curtain coater, or a spray coater can be employed. It can be suitably used depending on the thickness to be applied, the viscosity of the varnish, and the like.

  As a method for drying and curing the applied varnish, a normal heating and drying furnace can be used. As the atmosphere of the drying furnace, air, inert gas (nitrogen, argon) or the like can be used. The drying temperature is appropriately selected depending on the boiling point of the solvent, but a temperature range of 60 to 600 ° C. is preferably used. The drying time is appropriately selected depending on the thickness, concentration, and type of solvent, but is preferably about 0.05 to 500 minutes.

  In addition, the appearance of the finished polyimide metal laminate is measured at 23 ° C, 50 mm, with a strip of 35 mm and a length of 2 mm to avoid problems during transportation and focusing during the exposure process. It is preferable that the warpage of both MD and TD is 3 mm or less when left at% RH for 24 hours or more. Furthermore, the warpage of the entire polyimide layer after etching away the metal must be 3 mm or less for both MD and TD in order to facilitate the mounting of parts and devices, and the work for incorporation into mobile phones and video cameras. preferable.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In addition, the physical property in an Example was measured with the following method.
(1) Glass transition temperature (Tg)
The varnish synthesized on the copper foil (brand name F0-WS) manufactured by Furukawa Circuit Foil Co., Ltd. was applied to a dryness of about 20 μm and heated at 7 ° C / min in an oven purged with nitrogen to 50-270 ° C. After drying and imidization, the film obtained by etching away the copper foil was subjected to loss elastic modulus (E) obtained with a solid viscoelasticity device RSAII (manufactured by Rheometrics) at a nitrogen atmosphere, 1 Hz, and a heating rate of 5 ° C / min. ”) To obtain the peak
(2) Linear expansion coefficient (ppm / ° C)
Using TMA-4000 manufactured by Mac Science (currently Bruker XS), a non-thermoplastic polyimide film with a width of about 4 mm and a length of about 20 mm is placed in an air atmosphere, a load of 0.049 N, and a heating rate of 10 ° C./min. After measuring the amount of expansion and contraction, average linear expansion coefficients of 100 to 200 ° C. and 250 to 350 ° C. are calculated, respectively.
(3) Peel strength (kN / m)
A conductor with a length of 50 mm and a width of 1 mm is formed by etching a metal foil with a ferric chloride solution heated to 40 ° C., washing with water and drying at room temperature, and in accordance with the method prescribed in JIS C-6471 The metal conductor side is peeled off from the polyimide layer from the edge of the side, the peel angle is 90 °, and the stress when the peel speed is 50 mm / min is measured and calculated.
(4) Warpage (mm)
"Before copper etching"
Etching resist is applied, dried, exposed and developed so that the conductor pattern is 35mm wide x 2mm long, etched with 40 ° C ferric chloride solution (40 Baume), and then the excess polyimide film is cut. After forming a measurement sample and leaving it for 24 hours or more in an atmosphere of 23 ° C. × 50% RH, place the sample as shown in FIG. 1 with an magnifying projector (PJ-300 manufactured by Mitutoyo Corporation), and the maximum warpage Measure (R). The direction of warping was defined as positive when the metal layer was in the convex state as shown in FIG.

"After copper etching"
Etch the metal foil of the polyimide metal foil laminate with 40 ° C ferric chloride solution (40 Baume) to make a polyimide-only film, then cut the film to be 35mm wide x 2mm long Then, a measurement sample was formed, and the amount of warpage was measured under the same conditions as the “before copper etching” sample. The direction of warping was defined as positive when the metal layer was in the convex state with the metal layer inside.

Abbreviations for the solvents, acid dianhydrides, and diamines used in the examples are as follows.
DMAc: N, N-dimethylacetamide NMP: N-methyl-2-pyrrolidone PPD: p-phenylenediamine ODA: 4,4′-diaminodiphenyl ether m-BP: 4,4′-bis (3-aminophenoxy) biphenyl APB : 1,3-bis (3-aminophenoxy) benzene BPDA: 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride PMDA: pyromellitic dianhydride BTDA: 3,3 ′, 4,4 '-Benzophenone tetracarboxylic dianhydride

Synthesis example 1
<Synthesis of thermoplastic polyimide precursor>
To a container equipped with a stirrer and a nitrogen introduction tube, DMAc 1718.6 g was added as a solvent, 146.2 g of APB was added thereto, and the mixture was stirred at room temperature until dissolved. Thereafter, 157.1 g of BTDA was added and stirred at 60 ° C. to obtain a polyamic acid solution. The obtained polyamic acid solution had a polyamic acid content of 15% by weight, an E-type viscosity at 25 ° C. of 500 mPa · s, and a Tg of 195 ° C.

Synthesis example 2
<Synthesis of thermoplastic polyimide precursor>
In a vessel equipped with a stirrer and a nitrogen introduction tube, 714.9 g of DMAc solvent was added, and 24.86 g (30 mol%) of APB and 39.75 g (70 mol%) of ODA were added thereto, and stirred at room temperature until dissolved. It was. Thereafter, PMDA was added with a total diamine mole of 1, 60.3 g of 0.975 mole, and stirred at 60 ° C. to obtain a polyamic acid solution. 1,3-bis (3-maleimidophenoxy) benzene was added to the resulting varnish so as to be 10 wt% with respect to the polyamic acid, and the mixture was stirred at room temperature for 2 hours. The obtained polyamic acid solution had a polyamic acid content of 15% by weight, an E-type viscosity at 25 ° C. of 300 mPa · s, and a Tg of 313 ° C.

Synthesis example 3
<Synthesis of non-thermoplastic polyimide precursor>
To a container equipped with a stirrer and a nitrogen introducing tube, 846.9 g of DMAc and 362.9 g of NMP were added as solvents, and 16.2 g (30 mol%) of PPD and 49.1 g (49 mol%) of ODA were added thereto. Heated to ~ 60 ° C to dissolve. Then, after cooling to about 30 ° C. with ice, 25.1 g of BPDA was added, heated to 60 ° C. and stirred for about 2 hours. Furthermore, m-BP 38.7g (21mol%) was added, and it stirred, keeping temperature at 60 degreeC. Finally, 84.4 g of PMDA was added and stirred at 60 ° C. for 2 hours to obtain a polyamic acid solution. The obtained polyamic acid solution had a polyamic acid content of 15% by weight and an E-type viscosity at 25 ° C. of 400 mPa · s.

Synthesis example 4
<Synthesis of non-thermoplastic polyimide precursor>
To a container equipped with a stirrer and a nitrogen introduction tube, 644 g of DMAc and 161 g of NMP are added as solvents, 40.5 g (75 mol%) of PPD and 17.5 g (17.5 mol%) of ODA are added thereto, and 50-60 with stirring. Heated to ° C to dissolve. Then, after cooling to about 30 ° C. with ice, 78.0 g of BPDA was added and heated to 60 ° C. and stirred for about 2 hours. Further, 13.8 g (7.5 mol%) of m-BP was added and stirring was performed while maintaining the temperature at 60 ° C. Finally, 51.3 g of PMDA was added and stirred at 60 ° C. for 2 hours to obtain a polyamic acid solution. The resulting polyamic acid solution had a polyamic acid content of 20% by weight and an E-type viscosity at 25 ° C. of 19000 Pa · s.

Synthesis example 5
<Synthesis of non-thermoplastic polyimide precursor>
In a container equipped with a stirrer and a nitrogen introduction tube, 199.5 g of NMP was added as a solvent, and 15.51 g of PPD was added thereto and stirred at room temperature until dissolved. Thereafter, 41.99 g of BPDA was added in four portions and stirred at 60 ° C. to obtain a polyamic acid solution. The obtained polyamic acid solution had a polyamic acid content of 23% by weight, and an E-type viscosity at 25 ° C. of 55000 mPa · s.

Synthesis Example 6
<Synthesis of non-thermoplastic polyimide precursor>
To a container equipped with a stirrer and a nitrogen introduction tube, 189.9 g of NMP was added as a solvent, and 3.6 g (25 mol%) of PPD and 20.0 g (75 mol%) of ODA were added thereto and stirred at room temperature until dissolved. . Thereafter, 16.76 g (58 mol%) of PMDA and 16.37 g (42 mol%) of BPDA were added and stirred at 60 ° C. to obtain a polyamic acid solution. The obtained polyamic acid solution had a polyamic acid content of 23% by weight and an E-type viscosity at 25 ° C. of 25900 mPA · s.
Example 1

  The polyamic acid solution of Synthesis Example 6 (hereinafter referred to as varnish) is applied to glass with an applicator, dried at about 100 ° C. for 30 minutes, the polyamic acid film is peeled off from the glass, fixed to the support frame, and then about 150 ° C. for 10 minutes. About 200 ° C. for 10 minutes, about 250 ° C. for 10 minutes, about 300 ° C. for 10 minutes, and about 370 ° C. for 10 minutes for imidization reaction and solvent removal, thereby obtaining a 25 μm thick non-thermoplastic polyimide film.

Then, the varnish of Synthesis Example 1 was applied to the first surface of the non-thermoplastic polyimide film by a bar coater so that the thickness after drying was 2 μm, dried at 150 ° C. for 2 minutes, and then the second surface of Synthesis Example 3 was applied. The varnish is applied with a roll coater so that the thickness after drying is 2 μm, dried at 70 ° C. for 5 minutes and 110 ° C. for 5 minutes, and then dried in a drying oven at 140 ° C. for 2 minutes, 180 ° C. for 5 minutes, and 265 ° C. for 2 minutes. The polyimide insulation film whose 1st surface is a thermoplastic polyimide resin layer and 2nd surface is a non-thermoplastic polyimide resin layer was obtained. Then, the metal foil and the insulating film were placed on the side of the metal foil under the condition of pressure of 2.5 MPa at 260 ° C. with a press machine using silicon rubber as a cushioning material on electrolytic copper foil (F0-WS thickness 9 μm manufactured by Furukawa Circuit Foil Co., Ltd.) Were laminated so that the thermoplastic polyimide layer was in contact with each other, and then annealed in a batch type autoclave at a temperature of 300 ° C. for 4 hours in a nitrogen atmosphere to obtain a polyimide metal laminate. Table 1 shows the linear expansion coefficient of the non-thermoplastic polyimide film and the evaluation results of the obtained polyimide metal foil laminate.
Example 2

On the same copper foil as in Example 1, the varnish of Synthesis Example 2 was applied with a bar coater so that the thickness after drying was 0.5 μm, dried at 80 ° C. for 10 minutes, and further, Synthesis Example 4 The dried varnish was applied with an applicator so that the thickness after drying was 10 μm, dried at 100 ° C. for 15 minutes, and further the varnish of Synthesis Example 1 was applied with a bar coater so that the thickness after drying was 2 μm. After drying at 80 ° C. for 10 minutes, drying at 150 ° C. for 10 minutes, 180 ° C. for 10 minutes, 240 ° C. for 10 minutes, 270 ° C. for 10 minutes, and then drying at 450 ° C. for 10 minutes in a nitrogen atmosphere, copper foil / thermoplastic polyimide / A laminated board having a configuration of non-thermoplastic polyimide / thermoplastic polyimide was obtained. Next, the non-thermoplastic polyimide film was produced in the same manner as in Example 1, and pressed and annealed in the same manner as in the previous laminate and Example 1, to obtain a polyimide metal laminate. The linear expansion coefficient of the non-thermoplastic polyimide film and the results of evaluating the obtained polyimide metal foil laminate are shown in Table 1.
Example 3

  The varnish of Synthesis Example 5 was applied to glass with an applicator, dried at about 100 ° C. for 30 minutes, the polyamic acid film was peeled off from the glass, fixed to the support frame, and then fixed at about 150 ° C. for 10 minutes, about 200 ° C. for 10 minutes, about Heating at 250 ° C for 10 minutes, about 300 ° C for 10 minutes, and about 370 ° C for 10 minutes performs imidization reaction and desolvation, then removes the film from the support frame, and further puts it on a stainless steel plate at 350 ° C for 30 minutes under a nitrogen atmosphere Annealing was performed in a sandwiched state to obtain a non-thermoplastic polyimide film having a thickness of 25 μm.

  Thereafter, lamination with copper foil was carried out in the same manner as in Example 1 to obtain a polyimide metal laminate. The linear expansion coefficient of the non-thermoplastic polyimide film and the results of evaluating the obtained polyimide metal foil laminate are shown in Table 1.

Comparative Example 1
The varnish of Synthesis Example 5 was applied to a glass with an applicator, dried at about 100 ° C. for 30 minutes, the polyamic acid film was peeled off from the glass, fixed to the support frame, and then fixed at about 150 ° C. for about 10 minutes, about 200 ° C. for about 10 minutes, about The imidization reaction and the solvent removal were carried out by heating at 250 ° C. for 10 minutes, about 300 ° C. for 10 minutes, and about 370 ° C. for 10 minutes to obtain a non-thermoplastic polyimide film having a thickness of 25 μm. Thereafter, lamination with copper foil was carried out in the same manner as in Example 1 to obtain a polyimide metal laminate. The linear expansion coefficient of the non-thermoplastic polyimide film and the results of evaluating the obtained polyimide metal foil laminate are shown in Table 1.

  Widely used for flexible wiring boards, because the warpage during circuit processing and after processing is small and the anisotropy of warpage is small, so that a polyimide metal laminate can be obtained that has good workability during subsequent device and component mounting. it can.

This is a supplement to the warpage measurement method.

Claims (2)

A laminate having a polyimide film including at least one non-thermoplastic polyimide film layer, a metal layer, and a thermoplastic polyimide layer for bonding the polyimide film and the metal layer,
The non-thermoplastic polyimide film layer is
A thickness of 3～25Myuemu, and the width direction and length direction, the absolute value of the average linear expansion coefficient difference at 100 ° C. to 200 DEG ° C. is adjusted to 0 ppm / ° C. or higher 6 ppm / ° C. within the following ranges And
In both the width direction and the length direction, the average linear expansion coefficient at 100 ° C. to 200 ° C. is adjusted within the range of 11 ppm / ° C. to 19.3 ppm / ° C., and the width direction and the length direction In any case, the average linear expansion coefficient at 250 ° C. to 350 ° C. is adjusted within the range of −10 ppm / ° C. to 100 ppm / ° C.,
The thermoplastic polyimide layer includes a thermoplastic polyimide having a glass transition temperature of 150 ° C. to 350 ° C.,
A polyimide metal laminate characterized by that. The polyimide metal laminate according to claim 1, comprising a polyimide film including at least one non-thermoplastic polyimide film layer, a metal layer, and a thermoplastic polyimide layer that bonds the polyimide film and the metal layer. A manufacturing method of
Providing a non-thermoplastic polyimide film;
In the non-thermoplastic polyimide film, the absolute value of the difference in average linear expansion coefficient between 100 ° C. and 200 ° C. in the width direction and the length direction is 0 ppm / ° C. or more and 6 ppm / ° C. or less; In either case, the average linear expansion coefficient at 100 ° C. to 200 ° C. is 11 ppm / ° C. or more and 19.3 ppm / ° C. or less; and the average linear expansion coefficient at 250 ° C. to 350 ° C. in both the width direction and the length direction. Is a step of performing heat annealing so as to be −10 ppm / ° C. or more and 100 ppm / ° C. or less,
Laminating the heat-annealed non-thermoplastic polyimide film and the metal foil at a temperature of 200 to 400 ° C. through a thermoplastic polyimide layer having a glass transition temperature of 150 to 350 ° C. A method for producing a polyimide metal laminate .

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