JP2002047360A - Polyphenylene sulfide film and method of preparing the same and circuit board produced from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a polyphenylene sulfide film suitable as an insulating base material which is excellent in such properties for a circuit board as high frequency, low hygroscopicity, flame retardancy, solder resistance, thermal dimensional stability, hot melt workability or the like, and also to prepare a circuit board produced from the same. SOLUTION: The polyphenylene film (PPS) has a solder resistance of 260 deg.C<=, a thermal shrinkage of <=0.05 in every direction of the film at 200 deg.C for 5 minutes, a dimensional change ratio of <=1% in every direction of the film by using TMA, when temperature is increased from a room temperature to 200 deg.C and is again lowered to the room temperature and a small endothermic peak (Tmeta) appeared before the melting of a crystal in the range between >=(Tm-80) deg.C and <= a melting point (Tm) by a differential scanning calorimetry(DSC).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyphenylene sulfide film, a method for producing the same, and a circuit board using the polyphenylene sulfide film as a base material.

[0002]

2. Description of the Related Art In the field of electric and electronic parts, various characteristics such as solder heat resistance, high dimensional stability against heat and humidity, low water absorption and high frequency characteristics are considered to be high dimensions from the viewpoint of miniaturization and high performance of equipment. There is an increasing demand for an insulating base material that is balanced by:

Conventionally, as a circuit board (wiring board) used as a component of an electric / electronic device, a substrate made of glass cloth impregnated with an epoxy resin (hereinafter abbreviated as glass epoxy substrate), a polyimide film, a fluorine-based material, A base material in which a film and a glass cloth are impregnated with a fluororesin is used. Further, as a circuit board, a board using polyphenylene sulfide (hereinafter abbreviated as PPS) as a base material has been proposed. Specifically, as a circuit board having PPS as a base material, a fiber sheet made of a fibrous material and a resin composition containing PPS as a main component (JP-A-5-3109)
No. 57 gazette).

[0004]

However, these conventional substrates each have the following problems. Glass epoxy substrates are inferior in high-frequency characteristics, and have problems with moisture absorption characteristics.As the frequency increases, the dielectric characteristics further deteriorate.In addition, the laser method cannot be used for through-hole processing, and there is a limit to fineness. is there. Further, the polyimide film is excellent in heat resistance, but is inferior in high frequency characteristics and dimensional stability under moisture absorption. In addition, a substrate in which a fluorine-based film and a glass cloth are impregnated with a fluororesin has a problem that printing or lamination of a metal foil at the time of forming a circuit or paste or plating at the time of through-hole processing is difficult to mount.

[0005] In the case of an unstretched sheet, the PPS film satisfies properties such as low moisture absorption, flame retardancy and high-frequency characteristics, but has insufficient heat resistance as compared with a biaxially oriented film, and is not processed. As the number of processes increases, crystallization proceeds and the process becomes brittle. When the crystal size and the like are controlled, there is no problem in terms of heat resistance and brittleness, but there is a problem that heat deformation easily occurs when heat is applied suddenly as in soldering.

A biaxially oriented PPS film has a high heat shrinkage. For example, when heat is applied in the process of manufacturing a circuit board, the film is deformed due to heat shrinkage, and circuit misalignment is likely to occur. For this reason, processing to reduce the thermal shrinkage by annealing or the like is performed. However, when the thermal shrinkage at 250 ° C. is set to 1% or less, there is a problem that the flatness of the film is significantly deteriorated. .

In the case of a sheet-like material in which a PPS resin is impregnated with a fibrous material such as glass cloth, heat resistance, thermal dimensional stability, moisture absorption, flame retardancy and high frequency characteristics are excellent.
When a force such as bending is applied, cracks occur, and heat-fusibility is poor, and there is a problem in workability of a circuit board. In particular,
In fields where thinning and heat-fusibility are required, applications have been limited.

An object of the present invention is to solve the above-mentioned problems, that is, to improve the PPS while maintaining the surface properties of the film.
Utilizing the excellent high frequency characteristics, low moisture absorption and flame retardancy of
A PPS film suitably used as an insulating base material having excellent workability as a circuit board, such as heat resistance, thermal dimensional stability, heat fusion workability, and through-hole workability, a method for producing the same, and the use of the PPS film. To provide a circuit board.

[0009]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by a heat-treated polyphenylene sulfide film, and have reached the present invention.

That is, the polyphenylene sulfide film of the present invention is (a) a polyphenylene sulfide film comprising a polyphenylene sulfide resin and having a solder heat resistance of 260 ° C. or higher, and (b)
Made of polyphenylene sulfide resin and 200 ° C
Is a polyphenylene sulfide film characterized by having a heat shrinkage of 5% or less in all directions of the film in (c), comprising (c) a polyphenylene sulfide resin, and having a solder heat resistance of at least 260 ° C. A polyphenylene sulfide film characterized in that the heat shrinkage at 200 ° C. for 5 minutes is 0.05% or less in all directions of the film.

[0011] A circuit board according to the present invention is characterized in that an electric circuit is provided on at least one surface of the above-mentioned polyphenylene sulfide film.

The method for producing a polyphenylene sulfide film of the present invention is characterized in that a polyphenylene sulfide film consisting of a single layer or a multilayer is heat-treated at a temperature range of 200 ° C. to 350 ° C. for a period of 1 minute to 10 hours. This is a method for producing a polyphenylene sulfide film.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below.

The polyphenylene sulfide film of the present invention is basically composed of a polyphenylene sulfide (PPS) resin.

The polyphenylene sulfide resin referred to in the present invention is a resin containing preferably at least 70 mol%, more preferably at least 80 mol% of a PPS component. Such PP
If the S component is less than 70 mol%, the crystallinity and thermal transition temperature of the polymer are low, and various characteristics such as low moisture absorption, flame retardancy and high frequency characteristics characteristic of the resin composition containing PPS as a main component are impaired. Sometimes.

In the above PPS resin, if it is less than 30 mol% of the repeating unit, preferably less than 20 mol%,
A unit containing another copolymerizable sulfide bond may be contained. As a repeating unit of less than 30 mol%, preferably less than 20 mol% of the repeating unit, for example, a trifunctional unit, an ether unit, a sulfone unit, a ketone unit, a meta bonding unit, an aryl unit having a substituent such as an alkyl group, Specific examples include a biphenyl unit, a terphenylene unit, a vinylene unit, and a carbonate unit, and one or more of them can be used. In this case, the constituent unit is
Any of random or block copolymerization methods may be used.

The molecule of the PPS resin is preferably a straight-chain or linear polymer having a molecular weight of 50,000 or more, but the present invention is not limited to this. A polymer having a crosslinked structure may be used.

In the present invention, by using PPS which has been crosslinked / high molecular weight by heating in advance as the PPS resin, the object can be achieved with a short heat treatment time of the film. A specific method for cross-linking / polymerizing the PPS resin is to use a heating vessel in an atmosphere of an oxidizing gas such as air or oxygen or in a mixed gas atmosphere of the oxidizing gas and an inert gas such as nitrogen or argon. A method in which heating is performed at a predetermined temperature until a desired melt viscosity is obtained can be exemplified. The heat treatment temperature is usually 170
To 280 ° C., preferably 200 to 270 ° C., and the time is usually 0.5 to 100 hours, preferably 2 to 50 hours. You can get the level.

The PPS resin may contain a low molecular weight oligomer. The molecular weight distribution of the low molecular weight oligomer is in the range of 100 to 2000, and the low molecular weight oligomer contained in the PPS resin can be removed by washing with a solvent such as diphenyl ether. In the present invention, the treatment in boiling xylene for 36 hours is performed. Is preferably 1.5% by weight or less.

In the present invention, the PPS resin may be used alone or as a polymer alloy.
As polymer for alloy, use polyester, liquid crystal polyester, polyamide, polyolefin, polyimide, polyamide imide, polyether imide, polyarylate, polyether imide, modified polyphenylene sulfide, polyether ether ketone, polyether sulfone, polysulfone, etc. But not limited to these. The mixing ratio of the alloy polymer to the PPS resin is preferably about 0.1 to 30% by weight.

The PPS film of the present invention has a solder heat resistance of at least 260 ° C., preferably at least 280 ° C., more preferably at least 290 ° C. 260 ° C solder heat resistance
If it is less than the above, it may be deformed or warped during soldering. In addition, lead-free solder has been pointed out and lead-free solder has been put into practical use. However, lead-free solder has a melting point higher than that of conventional solder by 30 ° C or more, and must have a solder heat resistance of 290 ° C or more. Is preferred. Of course, the higher the solder heat resistance, the better, but for that purpose, the heat treatment temperature of the film also increases, and the surface properties of the film deteriorate. Therefore, the upper limit of practical use is about 310 ° C. as the solder heat resistance.

In the PPS film of the present invention, 20
It is necessary that the heat shrinkage for 5 minutes at 0 ° C. is not more than 0.05% in all directions of the film. 200 ° C
When the heat shrinkage ratio in the above is more than 0.05%, the circuit is likely to be deformed or misaligned during the production of the circuit board. The smaller the heat shrinkage ratio, the better. Here, the heat shrinkage rate is 20
The amount of dimensional change when aged at a temperature of 0 ° C. for 5 minutes is divided by the sample length before aging and expressed as a percentage.

The polyphenylene sulfide film of the present invention is a multilayer film having the same or different degrees of orientation, such as a biaxially oriented film of the above-mentioned PPS resin or a laminated film of a biaxially oriented film and an unoriented film. It can be suitably obtained by heat treatment. The heat-treated film may be used as a biaxially oriented PPS film alone or as a biaxially oriented PP film.
It can be used as a film laminated like an S film / biaxially oriented PPS film, or a film in which an unoriented PPS film is laminated on at least one surface of a biaxially oriented PPS film. The effect of the heat treatment is an effect of improving the solder heat resistance temperature of the PPS film and reducing the heat shrinkage at 200 ° C. However, when a biaxially oriented PPS film is subjected to heat treatment, the flatness tends to deteriorate due to heat shrinkage. For this reason, a measure is taken to constrain the width and / or longitudinal direction of the film and shrink it at a predetermined rate. On the other hand, when a film in which an unoriented PPS film is laminated on at least one surface of a biaxially oriented PPS film is heat-treated, the heat shrinkage can be reduced while maintaining better film flatness. Further unoriented PP
In a three-layer laminated PPS film in which an S film is used as a core layer and a biaxially oriented PPS film is disposed on both surface layers, better planarity can be obtained. In this case, the width direction and / or the vertical direction of the film can be reduced. Heat treatment can be performed without restraint.

As described above, when only the non-oriented PPS film is heat-treated, it becomes very brittle because it is not stretch-oriented and cannot be used for a circuit board to be bent and used. A long time is required for the heat treatment. On the other hand, by forming a laminated film in which an unoriented PPS film and a biaxially oriented PPS film are laminated, even when subjected to a heat treatment, the film does not become brittle and has excellent flatness and solder heat resistance. A film having a small shrinkage can be obtained, and the above problem can be solved.

Prior to lamination of the PPS film,
It is preferable to subject the surface of the unoriented film made of PPS and / or the biaxially oriented film to a corona discharge treatment, an ultraviolet treatment, a plasma treatment or the like according to the purpose.

As a method of laminating the PPS film,
For example, biaxially oriented PPS is provided on both sides of an unoriented PPS film.
When laminating films, (1) heat-sealing three sheets under high temperature and pressure, (2) melt-extruding PPS directly between two biaxially oriented PPS films, or (3) A method of applying an adhesive to the adhesive side of the oriented PPS film or the biaxially oriented PPS film, and laminating by a roll press, a hot plate press, or the like may be used.

Among these methods, in the above method (1), the temperature is 180 ° C. to 270 ° C., the pressure is 1 to 20 kg.
/ Cm ^{2 by} a roll press, a hot plate press or the like. In the case of laminating three layers in this manner, first, a two-layer body is prepared under the above conditions, and a biaxially oriented PPS is further formed on the unoriented PPS film side of the obtained two-layer body.
Films can be laminated or three layers can be laminated simultaneously. As described above, in the present invention, a multilayer polyphenylene sulfide film structure in which polyphenylene sulfide films having the same or different degrees of orientation are laminated can be obtained.

The PPS film of the present invention is a biaxially oriented PPS
Although it may be a film, it is preferably a laminated film in which an unoriented PPS film is laminated on at least one surface of a biaxially oriented PPS film, and more preferably a non-oriented PPS film.
A laminated film in which a biaxially oriented PPS film is laminated on both sides of a PS film is preferable. In the case of a laminated film composed of an unoriented PPS film and a biaxially oriented PPS film, the thickness of the unoriented PPS film relative to the total film thickness is preferably in the range of 20 to 90% from the viewpoint of balancing each property, and more preferably. It is in the range of 40-80%.

At least one of the PPS films of the present invention is preferably biaxially oriented.
The degree of orientation of the PS film is preferably in the range of 0.07 to 1.0, and more preferably in the range of 0.5 to 0.7. The degree of orientation as used herein refers to Through, Edge, and End measured by a wide-angle X-ray diffraction method.
The orientation degree measured in each direction is referred to, and the orientation degree in any of the above directions is preferably in the range of 0.07 to 1.0, more preferably a biaxially oriented film in the range of 0.5 to 0.7. Is preferred. Here, the degree of orientation measured from a certain direction means that an X-ray plate photograph is taken by X-ray incidence from that direction, and the intensity of diffraction from the (200) plane of the PPS crystal is measured on the equator with a microdensitometer. Ratio of black point degree I (φ = 30 °) in the 30 ° direction as well as black point degree I (φ = 0 °) when scanning in the direction I (φ = 30 °) /
I (φ = 0 °). Therefore, unoriented P
The PS film preferably has a degree of orientation of less than 0.07. The smaller the degree of orientation, the better.

In the laminated film, the difference in the degree of orientation of each layer can be found from the difference in the lightness and darkness caused by the difference in the orientation of each layer by cutting out the cross section of the film as an ultrathin section and observing it with polarized light. The Raman spectrum of the cross section of the film is measured with polarized light, and the difference in the degree of orientation of each layer can be measured based on the intensity ratio of the Raman band in each measurement direction.

The PPS film of the present invention can be used at room temperature to 20%.
The dimensional change at room temperature when the temperature is raised to 0 ° C. and returned to room temperature is preferably 1% or less, and more preferably 0.3% or less in all directions of the film. If the dimensional change rate exceeds 1%, a circuit shift occurs in a processing step of mounting components, and the yield decreases. Here, the dimensional change rate was determined by thermomechanical analysis (TMA). A sample having a width of 4 mm and an initial length of 15 mm was subjected to a load of 4.67 g / mm ² and a temperature rise / fall rate of 20 ° C./min from room temperature. When the temperature was raised to 200 ° C. and returned to room temperature again under the same conditions, the dimensional change at room temperature was divided by the initial length,
It is expressed as a percentage. Here, room temperature is 23 ° C. ±
2 ° C.

In the PPS film of the present invention, the fine endothermic peak Tmeta by DSC is preferably in the range of not more than the melting point Tm and not less than (Tm-80) ° C, more preferably not less than (Tm-70) ° C. It is.
The minute endothermic peak Tmeta is a temperature corresponding to the heat treatment temperature of the film, is observed as a minute peak, and is generated due to melting of an incomplete portion of the crystal structure formed by the heat treatment. Therefore, there may be two or more minute endothermic peaks.

Further, the humidity expansion coefficient β of the PPS film of the present invention is desirably 4 (× 10 ⁻⁶ /% RH) or less. When the humidity expansion coefficient β exceeds 4 (× 10 ⁻⁶ /% RH), there is a drawback that the displacement of the conductor pattern occurs due to the moisture absorption expansion, and the yield decreases in the processing step of mounting the components.

As described above, as a method for producing a PPS film having special properties having specific solder heat resistance and heat shrinkage according to the present invention, a usual biaxially oriented PPS film, for example, a PPS film before processing is used. The heat of fusion ΔH _{1 of the} crystal is 35 J /
g or more, or a multilayer film obtained by laminating such a biaxially oriented PPS film and an unoriented PPS film is heat-treated at a temperature in the range of 200 to 350 ° C. near the melting point of PPS for 1 minute to 10 hours. Can be obtained. The heat treatment temperature may be increased stepwise or may be treated at the same temperature, but the film before heat treatment does not have high heat resistance, and it is preferable to perform the high temperature heat treatment stepwise. . For example, a multi-step heat treatment in which the temperature is increased to 260 ° C. after the treatment at 200 ° C. for 30 minutes, and the treatment is performed at a temperature of 260 ° C. for 1 hour. Further, in the multi-stage heat treatment, the heat shrinkage of the film in a wider temperature range can be reduced. It is needless to say that a stepwise heat treatment in which the temperature is lowered after the treatment at a high temperature and the heat treatment is further performed may be used.

The heating can be carried out in an ordinary atmosphere, in air containing ozone, or in an inert atmosphere such as in nitrogen. However, when the PPS film to be heat-treated at this time is an unoriented film only, the film is stretched and deformed by the heat treatment, and it is difficult to perform a heat treatment with a uniform appearance and good flatness, and the obtained film is brittle. And practicality is often lost. On the other hand, a biaxially oriented PPS film alone may be used, but the flatness is likely to deteriorate due to heat shrinkage. Therefore, a PPS film stretch-oriented on at least one side of an unoriented PPS film, specifically, a PPS film oriented biaxially in the longitudinal direction and / or the width direction, is laminated, and is laminated with ordinary air or ozone. By heating at 200 to 350 ° C. near the melting point for about 1 minute to 10 hours in air or an inert atmosphere containing P.
A PS film can be obtained.

These heat treatments can be carried out in a continuous process in the form of rolls or sheets obtained by stacking a large number of cut sheets. In order to reduce the heat shrinkage, it is effective to freely shrink the film by heat treatment, and it is preferable that the film be heat-treated in a state in which the longitudinal direction and / or the width direction of the film are unconstrained. Further, at this time, better flatness can be maintained by performing heat treatment while applying a pressure of 100 Pa or more to the film surface. Further, by using a laminated film of an unoriented PPS film and a biaxially oriented PPS film as a film, a film having better flatness can be obtained.

In the heat treatment, the heat treatment may be carried out in the above-mentioned air atmosphere or in an inert atmosphere. Alternatively, the heat treatment may be carried out after a crosslinking treatment with radiation or peracetic acid. In the present invention, after the above-described heat treatment, a relaxation treatment may be further performed. The relaxation process is
150 ° C. to 280
C. for 1 minute to 24 hours.

The PPS film of the present invention is particularly suitable as a base material for a circuit board. The circuit board of the present invention
An electric circuit is formed on at least one side of the PPS film. The electric circuit is an electric passage formed by patterning a conductor. As the conductor, a metal such as copper, aluminum, or iron, or a conductive paint containing copper, silver, carbon, or the like is generally used. Further, an electric component or an electronic component may be mounted on the electric circuit. Further, two or more circuit boards may be laminated. Drilling, laser, melt penetration method and the like are easy to drill in such a circuit board. The circuit is formed by applying a photosensitive resin to the metal foil attached to the PPS film, baking the circuit shape with light, removing the unexposed resin, and in the case of copper foil using an aqueous ferric chloride solution. Etching method, P
There is a method of pressing a PS film with a mold having a circuit shape to form the circuit shape, and pouring a conductive paint into the circuit portion. Since the PPS film of the present invention has particularly excellent thermal dimensional stability, it can be suitably used for a circuit forming method by press molding.

Next, a method for producing a PPS film of the present invention and a method for producing a circuit board using the PPS film will be specifically described, but the present invention is not limited thereto. As the linear PPS resin used in the present invention, a PPS resin produced by a known method can be used. For example, sodium sulfide and p-dichlorobenzene are reacted in an amide-based polar solvent such as N-methyl-2-pyrrolidone (NMP) at high temperature and high pressure. If necessary, a copolymer component such as trihalobenzene can be included. As a polymerization degree regulator, caustic potassium or an alkali metal carboxylate is added.
To carry out a polymerization reaction. After the polymerization, the polymer is cooled, and the polymer is converted into a water slurry and filtered through a filter to obtain a granular polymer. This is placed in an aqueous solution such as acetate for 30 to 100
Stirring at 10 ° C. for 10 to 60 minutes, and 30 to 30
After washing several times at 80 ° C. and drying, a PPS powder polymer is obtained. After washing the powdered polymer with NMP at an oxygen partial pressure of 10 Torr or less, preferably 5 Torr or less, 30-80
Wash several times with deionized water at ℃ and dry under reduced pressure of 5 Torr or less. The polymer thus obtained is a substantially linear PPS polymer (resin), and the melt crystallization temperature Tmc of the PPS resin is 160 to 190 ° C.
, A stable stretched film can be formed. Of course, if necessary, other polymer compounds, silicon oxide, magnesium oxide, calcium carbonate, titanium oxide, aluminum oxide, crosslinked polyester, crosslinked polystyrene, mica, talc, kaolin and other inorganic and organic compounds and thermal decomposition inhibitors, A heat stabilizer and an antioxidant may be added.

The PPS resin (raw material) thus obtained is supplied to a known extruder and melted under reduced pressure with a small amount of oxygen, and then the molten resin is appropriately removed in order to remove foreign substances in the raw material. Extrusion is performed while filtering through a filter, for example, a sintered metal, a porous ceramic, sand, a wire mesh, or the like.
After that, it is measured by a gear pump and then discharged from the die, and then adhered to the cooling medium such as the drum by a known adhesion method such as electrostatic application, air chamber method, air knife method or press roll method. It is cooled and solidified and quenched to obtain an unoriented amorphous PPS film.

Next, the obtained non-oriented amorphous PPS film was brought into contact with a heated roll by 90 to 13
After raising the temperature to 0 ° C, stretching in the longitudinal direction by 2.5 to 4 times, and once cooling, biting the end of the film with a tenter clip, stretching in the width direction by 2 to 4 times at 100 to 160 ° C Then, a biaxially oriented PPS film is obtained by performing a heat treatment at 200 to 280 ° C. for about 10 to 100 seconds under a relaxation of about 0 to 10%. Of course, the stretching method is not limited, and a simultaneous biaxial stretching method can be used instead of the sequential two-time stretching. At this time, the driving method of the film gripping clip includes a screw method, a pantograph method, and a linear motor driving method. However, a linear motor drive system is preferable because the stretching control can be easily performed. These production methods are described in JP-B-63-12772.

The heat of fusion Δ of the crystal thus obtained
The temperature of a biaxially oriented film having an H ₁ of about 38 J / g is raised at once at a temperature of 200 to 350 ° C. near the melting point of the biaxially oriented PPS film in an air atmosphere or an inert atmosphere, or stepwise. Let the temperature range from 1 minute to 10 minutes
After a heat treatment for about an hour, a relaxation treatment is performed at 150 to 280 ° C. for 1 minute to 24 hours to obtain a PPS film having a heat of fusion ΔH ₂ of 30 J / g or less.

The PPS film thus obtained has a solder heat resistance of 260 ° C. or higher and 5 ° C. at 200 ° C.
Heat shrinkage rate per minute is 0.05% or less.
When the temperature was raised to 00 ° C. and returned to room temperature, the dimensional change at room temperature was 1% or less, and the coefficient of humidity expansion β was 4 ppm /% RH.
Satisfies the following requirements. The method of providing a metal layer on the PPS film is such that a metal foil is superimposed on the surface of the PPS film, and a temperature of 200 to 300 ° C.
Assuming that the melting point of the S film is Tmk, Tmk−30 ° C.
The heat fusion is performed under the conditions of Tmk + 50 ° C. and a pressure of 1 to 30 kg / cm ² . Further, a metal layer can be provided on the surface of the PPS film by a method such as vapor deposition, sputtering, plating, or an adhesive.

A circuit board can be obtained by forming a desired circuit pattern on the metal layer of the insulating base material thus obtained by etching (for example, with an aqueous ferric chloride solution).
Further, a circuit board having electric circuits provided on both sides of the insulating base material of the present invention may be further laminated via a PPS film. Furthermore, a multilayer circuit board can be manufactured by combining an electric circuit with a circuit board provided with a conductor other than metal, for example, a conductive paste or the like by silk printing or the like, and performing heat fusion under the above conditions. Further, through holes may be provided in the above-mentioned multilayer circuit board. The through hole can be provided by a method such as a drill, a laser, and a melt penetration method. Further, the respective layers can be connected to each other by a method such as a plating method. Further, electronic components and the like are mounted on the circuit board by soldering or the like as necessary.

[Measurement Methods for Physical Properties] Next, the measurement methods used in the present invention will be described below.

1. Solder heat resistance According to JIS C5013, this refers to the maximum temperature at which a sample is immersed in a solder bath so that it can freely shrink, and the flatness does not deteriorate. The higher the temperature (° C.), the better the solder resistance.

2. Heat shrinkage ratio The direction of the film is set as the reference direction, cut out to 100 mm x 10 mm each in the reference direction and the 90 degree direction of the reference direction, mark the conductor part of the circuit, and accurately measure the distance between the marks in the longitudinal direction with a microscope. Read (xmm).
Next, after aging for 5 minutes in a furnace (hot air method) heated to a temperature of 200 ° C., the distance is accurately measured (ym
m). The heat shrinkage rate (%) in each direction was determined by the following formula, and the value was shown in the direction in which the heat shrinkage rate was large. 2. Heat shrinkage (%) = (xy) / xx100 Dimensional change rate by thermo-mechanical analysis (TMA) Thermo-mechanical analysis (TMA) was performed using a TMA / SS6100 manufactured by Seiko Instruments Inc. on a test film having a width of 4 mm and an initial length of 15 mm.
g / mm ² , and the temperature was raised from room temperature to 200 ° C. under the condition of a temperature rising / falling rate of 20 ° C./min. Expressed as a percentage.

4. Humidity expansion coefficient β (× 10 ⁻⁶ /% RH) A sample is cut out to a width of 10 mm, and a constant-load elongation tester (Nippon Automatic Control Co., Ltd., constant load) set in a thermo-hygrostat (PKL-50D manufactured by Daiei Chemical Co., Ltd.) Elongation testing machine), sandwich the sample so that the distance L between the chucks is 150mm,
Humidification from 5 RH% to 85 RH% at 25 ° C. (ΔRH = 8
0RH%), the humidity expansion coefficient β was determined by the following equation from the deformation amount ΔL. β = (ΔL / L) / ΔRH, and the unit is 10 ⁻⁶ /% RH.

5. Thermal characteristics As a differential scanning calorimeter, R manufactured by Seiko Electronics Industry Co., Ltd.
Using a DC-220 robot DSC and a disk session SSC / 5200 manufactured by the company as a data analyzer, a 5 mg sample was collected, and the temperature was raised from room temperature to a heating rate of 2%.
The minute endothermic peak Tmeta was measured in the course of heating to 350 ° C. at 0 ° C./min. Thereafter, the sample was taken out into the air, rapidly cooled, and again heated from room temperature at a rate of 20 ° C./min.
The endothermic peak area where the crystal appeared when the temperature was raised to 50 ° C. and melted was determined. In the case of a laminated film, the heat of fusion of all the laminated films was determined.

6. Fusing Characteristics (1) Thermal Fusing Characteristics A rolled copper foil having a thickness of 35 μm was fused to the surface of the sample at 320 ° C., and the state when the obtained laminated sheet was folded was evaluated according to the following criteria. ：: no peeling at the bent part △: peeling occurred at the bent part 30% of the bent part
Less than ×: Peeling generated at the bent part is 30% of the bent part
End 7. Flatness A sample obtained by cutting the film into a 150 mm square parallel to the longitudinal direction and the width direction was placed in parallel on a flat table, and the floating height of the film from the table was measured and divided into the following four ranks. ◎: less than 2 mm ○: 2 mm or more and less than 3 mm △: 3 mm or more and less than 5 mm ×: 5 mm or more

[0051]

(Example 1) A linear PPS resin (Ryton T1881) manufactured by Toray Industries, Inc. was used, and 0.12% by weight of thyroid 300 as an additive and 0.05% by weight of calcium stearate were added thereto. Was supplied to a known single-screw extruder having a cylinder diameter of 150 mm, and 310
After melting at 0 ° C., the mixture was passed through a filter box for cutting foreign substances of 10 μ or more, and extruded into a film from a T-die die having a lip width of 1200 mm and a lip gap of 1.5 mm. An electrostatic charge is applied to the molten film extruded in this manner, and a casting drum (diameter 8) having a surface temperature of 25 ° C.
(00 mm). The cast film thus obtained was an amorphous, non-oriented film. The obtained film is supplied to a longitudinal stretching machine comprising a group of heating rolls, stretched 3.6 times at a film temperature of 100 ° C., and subsequently stretched 3.5 times at 100 ° C. in a width direction using a tenter. Further, the film was heat-treated at 270 ° C. for 15 seconds, relaxed by 8% in the width direction of the tenter, and edge-cut off to obtain a biaxially oriented film having a thickness of 50 μm. Heat of fusion ΔH of crystals of this film measured by DSC
₁ was 39 J / g.

The thus obtained biaxially oriented PPS film having a thickness of 50 μm was rolled at 280 ° C.
After continuous heat treatment in air for 2 hours in an oven heated to a temperature of 290 ° C., continuous heat treatment was further performed in an oven heated to 290 ° C. for 2 hours. Thereafter, a relaxation treatment was performed at a temperature of 200 ° C. under no tension. From the DSC curve, the thus obtained film has a minute endothermic peak Tmeta of 210 ° C., and a heat of fusion ΔH _{2 of the} crystal of 29 J / g, which is colored brown, but has a solder heat resistance of 294 ° C. Yes, the dimensional change at room temperature measured by TMA was 0.05%, the flatness was good as ○, and the glossiness of the surface was high. Table 1 shows the characteristics.

Then, the thus obtained 50 μm
A 1 oz. (36 μm thick) rolled copper foil was heat-sealed on the PPS film. The method of heat fusion is hot plate press method,
The conditions for heat fusion were a temperature of 300 ° C., a pressure of 10 kg / cm ² , a pressing time of 1 hour, and rapid cooling to 50 ° C. in the pressed state. Next, the copper foil was etched into an electric circuit pattern with an aqueous ferric chloride solution to obtain a circuit board.

The circuit board thus obtained had good heat-sealing property with the copper foil. Table 1 shows the results.

(Example 2) The biaxially oriented PPS film obtained in Example 1 was superimposed on both sides of an unoriented PPS film before stretching cast in the same manner as in Example 1.
Under a condition of a temperature of 260 ° C. and a pressure of 10 kg / cm ² , they were laminated by hot plate pressing. The thickness configuration was such that the biaxially oriented PPS film portion of both surface layers was 50 μm, and the unoriented PPS film portion was 200 μm. The obtained laminated film was heat-treated in the same manner as in Example 1. The biaxially stretched PPS
The laminated film of the film / unoriented PPS film / biaxially oriented PPS film has a slightly endothermic peak Tmeta of 212 ° C. from the DSC curve and is colored brown, but has a solder heat resistance of 289 ° C. The measured dimensional change at room temperature was 0.25%, the flatness was also excellent with ◎, and a product having flexibility was obtained.
Table 1 shows the properties of the laminated film.

A rolled copper foil was heat-sealed on the laminated PPS film thus obtained in the same manner as in Example 1, and the copper foil was etched into an electric circuit pattern with an aqueous ferric chloride solution to obtain a circuit board. . The circuit board obtained in this manner had good heat-fusibility with a copper foil. Table 1 shows the results.

Example 3 A biaxially oriented PPS film obtained in the same manner as in Example 1 was subjected to a heat treatment at a temperature of 200 ° C. without tension for 1 hour, and then at 260 ° C. with no tension. For 1 hour. From the DSC curve, the film obtained in this manner showed a slight endothermic peak Tme.
ta is 210 ° C., 265 ° C., the film is colored brown, but the solder heat resistance is 260 ° C., the dimensional change at room temperature measured by TMA is 0.03%, and the flatness is ○. And the glossiness of the surface was high. Table 1 shows the characteristics.

A rolled copper foil was thermally fused on the PPS film thus obtained in the same manner as in Example 1, and the copper foil was etched into an electric circuit pattern with an aqueous ferric chloride solution to obtain a circuit board. The circuit board obtained in this manner had good heat-fusibility with a copper foil. Table 1 shows the results.

Example 4 The biaxial PPS film obtained in Example 1 was superimposed on both surfaces of an unoriented PPS film before stretching cast in the same manner as in Example 1.
Roll pressing was performed at a temperature of 260 ° C. and a linear pressure of 20 kg / cm. The resulting laminated PPS film is biaxially oriented PP
The S film portion was 50 μm, and the unoriented PPS film portion was 200 μm. The laminated PPS film was cut into a square of 50 cm square, and sandwiched between iron plates. Due to the weight of the iron plate, a surface pressure of 300 Pa is applied to the laminated PPS film. The width and the longitudinal direction of the film are unrestricted, and the film can freely shrink. In this state, heat treatment was performed in a hot air oven at 200 ° C. for 1 hour, and then the temperature of the hot air oven was increased to 260 ° C., and then heat treatment was performed for 1 hour. After heat treatment 4
It cooled to 30 degreeC over time, and the sample was obtained. The resulting film is a DS.
From the C curve, it was found that the endothermic peak Tmeta at 212 ° C.
° C, and the film is colored brown, but the solder heat resistance is 260 ° C, the dimensional change at room temperature measured by TMA is 0.01%, and especially the flatness is also excellent.
And the glossiness of the surface was high. Table 1 shows the characteristics.

A rolled copper foil was heat-sealed on the PPS film thus obtained in the same manner as in Example 1, and the copper foil was etched into an electric circuit pattern with an aqueous ferric chloride solution to obtain a circuit board. The circuit board obtained in this manner had good heat-fusibility with a copper foil. Table 1 shows the results.

(Comparative Example 1) The biaxially oriented PPS film obtained in Example 1 was subjected to the biaxially oriented PPS film without heat treatment.
Rolled copper foil was heat-sealed on the film in the same manner as in Example 1, and the copper foil was etched into an electric circuit pattern with an aqueous ferric chloride solution to obtain a circuit board.

When a biaxially oriented PPS film that had not been subjected to a heat treatment was floated in a solder bath, the film was deformed at 240 ° C. or higher and the flatness was deteriorated. In addition, the DSC curve showed a slight endothermic peak Tmeta of 255 ° C. and a dimensional change at room temperature measured by TMA of 3.0%. The circuit board obtained from the uncrosslinked biaxially oriented PPS film was not able to adhere well to the rolled copper foil because the biaxially oriented PPS film was thermally deformed when the rolled copper foil was thermally fused. Table 1 shows the properties of the biaxially oriented PPS film and the results of the heat fusion property with the copper foil.

Comparative Example 2 A heat treatment was performed in the same manner as in Example 1 except that the unoriented PPS film before stretching was heat-treated. When the obtained film was floated in a solder bath, the solder heat resistance was about 240 ° C.
From the C curve, the fine endothermic peak Tmeta was 210 ° C., indicating that the film was very brittle and not a practical film. The dimensional change at room temperature measured by TMA was 2%. Table 1 shows the properties of the unoriented crosslinked PPS film.

[0064]

According to the present invention, it is excellent in solder heat resistance, thermal dimensional stability, low hygroscopicity, flame retardancy and high frequency characteristics, and furthermore, as a circuit board for heat fusion workability and through hole processing. A polyphenylene sulfide film suitable as an insulating substrate having excellent processing characteristics and a circuit board using the same are obtained.

[0065]

[Table 1]

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/46 H05K 3/46 T // C08L 81:02 C08L 81:02 F term (reference) 4F071 AA62 AC09 AE05 AF04 AF39 AF40 AF45 AF47 AF53 AF54 AF61 AH13 BA01 BB06 BB07 BB08 BC01 4F073 AA07 AA10 AA12 AA21 AA29 BA32 BB01 GA01 5E346 AA05 AA06 AA12 AA22 AA32 AA51 CC08 DD02 DD34 EE05 EE19H12 EE05 GG18H13

Claims (16)

[Claims] 1. A polyphenylene sulfide film comprising a polyphenylene sulfide resin and having a solder heat resistance of 260 ° C. or higher. 2. A polyphenylene sulfide film comprising a polyphenylene sulfide resin and having a heat shrinkage at 200 ° C. for 5 minutes of 0.05% or less in all directions of the film. 3. A film made of a polyphenylene sulfide resin, having a solder heat resistance of 260 ° C. or higher, and a heat shrinkage of 0.2 mm at 200 ° C. for 5 minutes in any direction of the film.
Polyphenylene sulfide film characterized by being not more than 05%. 4. A multilayer polyphenylene sulfide film in which polyphenylene sulfide films having the same or different degrees of orientation are laminated.
4. The polyphenylene sulfide film according to any one of items 1 to 3. 5. The polyphenylene sulfide film according to claim 4, wherein an unoriented polyphenylene sulfide film is laminated on at least one surface of the biaxially oriented polyphenylene sulfide film. 6. The polyphenylene sulfide film according to claim 5, wherein the thickness of the unoriented polyphenylene sulfide film layer is in the range of 20 to 90% of the total film thickness. 7. A film made of a polyphenylene sulfide resin, wherein a dimensional change at room temperature when the temperature is raised from room temperature to 200 ° C. and returned to room temperature is 1% or less in all directions of the film. Item 7. The polyphenylene sulfide film according to any one of Items 1 to 6. 8. The polyphenylene sulfide film according to claim 7, wherein the dimensional change is 0.3% or less in all directions of the film. 9. A small endothermic peak (Tmeta) appearing before crystal melting by a differential scanning calorimeter (DSC) has a melting point (Tm).
The polyphenylene sulfide film according to any one of claims 1 to 8, wherein the temperature is in the range of (Tm-80) C or higher. 10. The polyphenylene sulfide film according to claim 1, wherein two or more minute endothermic peaks (Tmeta) are present. 11. The coefficient of hygroscopic expansion β is 4 (× 10 ⁻⁶ /% R).
H) Polyphenylene sulfide film according to any one of claims 1 to 10, wherein: 12. A circuit board comprising an electric circuit provided on at least one surface of the polyphenylene sulfide film according to claim 1. 13. A method for producing a polyphenylene sulfide film, comprising heat-treating a single-layer or multi-layer polyphenylene sulfide film at a temperature of 200 ° C. to 350 ° C. for 1 minute to 10 hours. 14. The method for producing a polyphenylene sulfide film according to claim 13, wherein the temperature is increased stepwise and the heat treatment is performed. 15. The method for producing a polyphenylene sulfide film according to claim 13, wherein a heat treatment is performed in a longitudinal direction and / or a lateral direction of the film using a single-wafer-shaped film in an unconstrained state. 16. The heat treatment while applying a pressure of 100 Pa or more to the film surface.
15. The method for producing a polyphenylene sulfide film according to any one of 15.