FR2500841A1 - Polyphenylene sulphide sheet of specified crystallinity - used for printed circuit board - Google Patents

Abstract

Sheet of high mole wt poly p-phenylene sulphide (PPS) has an index of crystallinity of 2.5-8.0, a crystallite size of 50-100 Angstroms and orientation factors above 0.70 in each of the through, Edge and End directions as measured by wide angle X-ray diffraction. Less than 1.5 wt% of the sheet can be extracted by chloroform. Sheet can be laminated to a thin metallic film to produce a printed circuit board. The PPS has better flexibility and impact resistance than known sheets of PPS, with less resk of cracking when boring or drilling holes through it.

Description

 The present invention relates to a sheet-like material, consisting mainly of poly (p-phenylene sulfide) (hereinafter referred to as PPS), and also to a printed circuit board or substrate employing this material. of the leaf kind.

 Conventionally, as a raw material for a flexible printed circuit board, a polyimide film has been widely used because of its superior thermal endurance.

The polyimide film, as described above, however, has drawbacks such that it is not only extremely expensive but is generally low against strong alkalis such as aqueous sodium hydroxide solution and the like to be used in method of manufacturing the printed circuit board, with a high moisture absorption capacity, this being thus accompanied by dimensional changes according to the humidity variations.

 On the other hand, the PPS formed in a sheet-like configuration having a low moisture-absorbing capacity, has superior performance in such areas as insulation resistance, thermal resistance and thermal insulation. , resistance to chirpic products, etc., and attention has been drawn to PPS as a raw material for printed circuit boards, such as flexible curtain panels or carrier strips for so-called thin wafers. IC.Particularly, the non-elongated PPS film, produced by heating and crystallization of substantially undirected film, has a simple manufacturing process and essentially has no residual deformation resulting from elongation, without any dimensional variation due to a hot shrinkage, even when subjected to a high temperature atmosphere and, therefore, considered to be a suitable substrate for printed circuit boards.

 However, since the conventional non-elongated PPS film has the disadvantages as described below, it can not be applied to end-uses requiring flexibility or flexibility over a long period of time, or including piercing during the process and, thus, it is extremely limited in its range of applicatio # ns in the present circumstances.

 More specifically, the drawbacks of the known PPS film have been such that, firstly, its flexibility, as represented by the folding endurance, is not good enough even immediately after manufacture, whereas this flexibility or this flexibility is reduced to an undesirable point in large proportion as time goes on, and as a result, it has been difficult to maintain favorable flexibility for long periods of time.

 Secondly, since conventional non-elongated PPS films are brittle and weak with respect to shocks, there have been troubles such that cracks or cracks tend to form around the peripheries of the bores or holes. or the films are broken at the location of these cracks in the worst cases, when this drilling is done by punching or drilling.

 Accordingly, it is a principal object of the present invention to provide an improved sheet-like material of non-elongated PPS having superior flexibility and being shock-resistant, with substantial elimination of the drawbacks inherent in conventional film films. Non-elongated PPS of this kind.

 Another object of the present invention is to provide an improved printed circuit board having favorable flexibility for long periods of time and also having a superior piercing ability, which utilizes the improved non-elongated PPS sheet of the type described above. .

To achieve these and other objects, according to a preferred embodiment of the present invention, there is provided a sheet-like material, comprising a composition consisting mainly of high molecular weight poly (p-phenylene sulfide), characterized in that a. the quantity of product extracted by chloro extraction
form is less than 1.5% by weight relative to the weight
total before extraction, and b) i) the crystallinity index is in the range of va
theirs greater than 2.5 and less than 8.0
ii) the crystallite size is in the range of
oo
values greater than 50 A and less than 100 A;
and
(iii) the orientation factors measured in three ways
across, at the edge and at the end are
respectively greater than 0.70, as measured
by the X-ray diffraction process at wide
angle.

en quantité de plus de 90 Ó en mole, et, de préférence, en quantité de plus de 95 tÓ en mole. Si cette unité de sulfure de phénylène orientée en para est en quantité inférieure à 90 Ó en mole, une cristallinité suffisante du polymère n'est pas disponible, alors qu'il est difficile d'obtenir un film supérieur par suite de la mauvaise endurance thermique durant la soudures etc.Further, according to the present invention, there is also provided an improved printed circuit board which comprises the improved sheet-like material of PPS, as described above, and a film or thin metal layer laminated thereon. The high molecular weight PPS to be employed in the present invention should contain the pattern as represented by the structural formula

in an amount of more than 90 mol%, and preferably in an amount of more than 95 mol%. If this para-oriented phenylene sulfide unit is less than 90 mol%, sufficient polymer crystallinity is not available, while it is difficult to obtain a superior film due to poor thermal endurance. during welds etc.

le motif d'éther

le motif de sulfone

le motif de biphényle

le motif de sulfure. de naphtalène

le motif de sulfure de phényle déplacé

où R représente un groupe allyle, le groupe nitro, le groupe phényle, un groupe alkylate), un motif de sulfure de phényle trifonctionnel

etc., dans une gamme telle que cela n'affecte pas grandement la cristallinité, l'aptitude à l'allongement et l'efficacité d'orientation du polymère, mais les comonomères doivent de préférence être en quantité inférieure à 5 % en mole.En particulier, on préfère que les comonomères multifonctionnels ayant une fonctionnalité supérieure à 3 soient en quantité inférieure à 1 Dó. With regard to the remaining amount of the polymer units of less than 10 -2, it is possible that this polymer contains the meta-oriented pattern.

the ether motif

the sulphone pattern

the biphenyl motif

the sulphide pattern. of naphthalene

the phenyl sulfide pattern moved

where R represents an allyl group, the nitro group, the phenyl group, an alkylate group), a trifunctional phenyl sulfide unit

etc., in such a range that it does not greatly affect the crystallinity, elongability and orientation efficiency of the polymer, but the comonomers should preferably be in less than 5 mol%. In particular, it is preferred that the multifunctional comonomers having a functionality greater than 3 be in an amount of less than 1%.

 In addition, it is necessary that the apparent melt viscosity of the polymer is in the range between 2,000 and 100,000 poises and preferably between 3,000 and 50,000 poises under conditions of a temperature of 3000C and a shear rate. of 200 (seconds) 1, and, furthermore, that the non-Newtonian coefficient (hereinafter referred to as the N-value), under the conditions indicated above, is preferably in the range between 0.9 and 2, Polymers with extremely high or low viscosity are not only preferable from the point of view of uniformity during extrusion, the surface condition of the resulting film, etc., but they also give rise to extreme difficulties during the process. biaxial elongation, whereas they are not preferable because, when the crosslinking content or the branching content is high, the value of N exceeding 2.0, the efficiency of orientation, the variation of 'thickness and the rough surface appearance, etc. by elongation are adversely affected.

Although there is no absolutely unique relationship between the apparent melt viscosity, the value
N and the so-called "melt flow index" (hereinafter referred to as MFI), generally used as an index for the melt viscosity of resins, the MFI of the
PPS that can be used in the present invention is in the range of approximately 10 to 130.

 On the other hand, as far as the degree of polymerization is concerned, the exact values are not available, since the measurements are difficult to take because of the lack of solubility of the PPS in the general organic solvents at the normal temperature, with marked differences according to comonomer compositions and degrees of crosslinking, etc. but the values can be considered to be in the region of approximately 50 to 1,000.

The addition of additives, such as antioxidants, heat stabilizers, lubricants, nucleating agents, ultraviolet radiation absorbing products, colorants, and the like. The PPS employed in the present invention, in a normally accepted amount, will not cause any particular problems. In addition, mixing small amounts of other kinds of polymers and
PPS of the present invention in such a range that does not interfere with achieving the objects of the present invention, to improve fluidity, fine tuning crystallimity and the like, also does not present a disadvantage.

 However, in cases where the sheet according to the present invention is to be used as an electrical insulation material additional care must be taken in preparing the PPS resin and in selecting the additives in order to avoid isolation of insulation resistance. . Although the PPS itself has an extremely favorable electrical insulation resistance, in the range of low temperatures to high temperatures, this electrical resistance is undesirably decreased in a marked amount, if any substance that serves as a support For electrical conduction (for example, metal ion or the like) is contained therein. Therefore, for the preparation of polymers, it is essential to carefully remove carrier substances such as an earth ion, etc. and, simultaneously, it is essential not to bring these substances to be added or mixed externally.

 In the sheet material of the present invention it is required that the amount of product extracted, when the chloroform treatment is carried out under the conditions as indicated later, be less than 1.5 m by weight. (Preferably 1.2% by weight) relative to the total weight before extraction. The foil material having this amount of extract product exceeding 1.5 OD by weight has poor flexibility and poor impact resistance, these properties being remarkably degraded as time goes by, and Accordingly, the objects of the present invention can not be achieved by this sheet.

 Although it is not clear why the PPS sheet having the high amount of product extracted, as described above, has lower flexibility and impact resistance, it can be assumed that this is attributed to the fact that the amorphous region of the heated and crystallized sheet to withstand flexibility and impact resistance, crystallites of a low molecular weight composition, which must be extracted with chloroform, are formed, thus resulting in a loss of this flexibility and this impact resistance.

 The crystal structure of the sheet material according to the present invention is characterized by the following three sets of parameters, as measured by the wide-angle X-ray diffraction method.

 First, the crystallinity index should be in the range of values greater than 2.5 and less than 8.0 (preferably above 3.0 and below 6.0). crystallinity number, as designated above, can be defined by the ratio (200 / I25) between the maximum intensity (I200) of the Miller index diffraction peak (200) of the PPS crystal in the diffraction pattern wide-angle x-rays of the sheet, and the intensity (I25) for 26 = 250C for the same profile.If the crystallinity index as described above is less than 2.5, the mechanical strength in a high temperature atmosphere, such as a solder bath, is low, with poor thermal endurance, whereas, when the crystallinity index exceeds 8.0, the resulting sheet becomes brittle or brittle, with loss of flexibility and impact resistance.

 Then, the dimensions of the PPS crystallites in the sheet (referred to as C.sub.SC below, i.e., apparent crystal dimensions) must be in the range of values greater than 50 and less than 50. 100. The crystallite size referred to above means the apparent crystallite size to be obtained by applying the Scheller formula to half the width of the Miller index diffraction peak of (200) of the PPS crystal. If the ACS is less than 50A, it may result in poor thermal endurance, while any sheet having an ACS value exceeding 100 is difficult to obtain in fact.

Thirdly, it is also required that the orientation factors as measured in three crosswise, edge and end directions (hereinafter referred to as Gold) must respectively be greater than 0.70. The orientation factor7 as measured in a certain direction as indicated above, is defined by the ratio of 9 = 308 / in = 0 between the photodensity (Id = f) 0), obtained by operating modes such as the fact than to take an X-ray plate image by the Laue method, by X-ray incidence in this certain direction, and scanning the diffraction ring (200) of the crystal of
PPS by a microphotensensometer in the radial direction along the equatorial line, and the photodensity (I = 300) obtained in a similar manner in a direction of 300.

 In addition, the cross direction designated above is represented by the direction perpendicular to the surface of the sheet, the direction on the edge by the direction parallel to the surface of the sheet and also to the transverse direction of the sheet, and the direction to the extrema by the direction parallel to the surface of the sheet and also to the longitudinal direction of this sheet. If the d> OF value as described above is less than 0.7, the thermal contraction is likely to occur as a result of the residual deformation after elongation.

Subsequently, the manufacturing process of the
sheet according to the present invention will be explained below.

 Firstly, the PPS polymer to be used for the production of the sheet-like material according to the present invention can be obtained by causing an alkali metal sulfide to react with a para-dihalobenzene in polar organic solvents under conditions high temperatures and high pressures. In particular, it is preferable to cause sodium sulfide to react with p-dichlorobenzene in polar high amide polar solvents such as N-methylpyrrolidone and the like. In the case indicated above, it is very desirable to carry out the reaction at temperatures from 2300.degree. C. to 2800.degree. C. by adding a product known as a polymerization modifier, such as a caustic alkali, or an alkali metal carboxylate, for the settings of the degree of polymerization. The pressure in the autoclave and the time for the polymerization can be suitably determined according to the kinds and amounts of modification products to be employed, depending on the desired degree of polymerization, etc. To maintain the electrical isolation performance of the film to be obtained finally, it is desirable to wash the polymerized polymer (generally in powder form) with non-metal ion-containing water to remove by-product salt, polymerization-modifying products, etc. ., thus to keep the concentration of the ion carriers low enough. In the case indicated above, the total ash content in the polymer should preferably be less than 5,000 ppm, the calcium being less than 1,000 ppm and sodium less than 50C ppm.

 The PPS polymer thus obtained is sent to a known melt extrusion equipment, represented by an extruder, to be converted into a sheet-like configuration, but, in the case where a larger quantity is required. Since the chloroform extract is contained in the polymer, the amount of product extracted from the sheet material does not fall within the range as defined by the present invention, and thus only one material of the foil type having poor flexibility and poor impact resistance is achieved.

 In the case as described above, it is desirable to pretreat the polymer before sending it to the forming process. For this purpose, it is possible to use, for example, a process whereby the polymer powder, obtained by polymerization and washing with water, is further washed or rinsed in a suitable organic solvent while being kept at temperatures above the temperature. ambient (preferably greater than 500C), under normal or increased pressure. The organic solvents which can be employed in the above treatment may be, for example, methylene chloride, NMP (N-methyl-pyrrolidone), chloroform, toluene, etc. Similarly, acetone heated to a temperature close to its boiling point may also be employed.

 During the formation of the PPS polymers according to the sheet-like configuration by the melt extruder equipment, the melt-form PPS is susceptible to gelation by contact with the melt. oxygen and, accordingly, it is desirable to replace the polymer inside the hopper of the extruder above. etc. by an inert gas or to reduce the pressure.

 The molten resin is continuously extruded from slot-shaped dies (eg T-die, circular die etc.) to be forcibly cooled. As a means for this force cooling, it is possible to selectively or selectively employ combination, a method for casting on a cooled metal drum, a method for spraying gas or liquid at low temperature or a method for immersion in a liquid at low temperatures or analongues.For forced cooling, as described herein above, the molten PPS is rapidly cooled to a temperature above the transition temperature in the vitreous state, for its one-time conversion into a sheet in the amorphous and undirected state. during forced rofroidlssemont, the stretching (stretching) of the sheet in the longitudinal direction or in the transverse direction, or years in both directions, not only does not present any problem may It is also preferable from the point of view of flexibility and impact resistance, as long as 110F of the finally obtained sheet is limited to values greater than 0.70. However, in general, this elongation must be performed in a state where the sheet temperatures are above 220-2300C. For example, a method can be used in which, immediately after extruding the PPS from the circular die an elongation of 3 to 10 times with respect to the surface is applied by the use of air pressure (so-called blowing or swelling process).

 In the manner as described above, the material formed in the configuration of a sheet as an intermediate product is obtained. "Sheet-like material" according to the present invention means a material formed as a thin sheet, having an approximate thickness of less than 5 mm, and generally represents formed articles normally referred to as films, sheets, plates, etc.

 Subsequently, a thermal constant deformation of the dimensions is performed in order to improve the heat endurance. The "thermal constant deformation of the dimensions" according to the present invention means a heat treatment under conditions such that the size variation, before and after the heat treatment, is less than + 20 o.

 The heat treatment, as described above, is carried out by bringing the sheet to be treated into contact with a flow of liquid or heated gas or with the surface of a solid (the "temperature" and the "time" for the treatment thermal to be mentioned later are nothing other than the temperature of the heating medium and the time of contact with this heating medium).

More specifically, the examples of this heat treatment may include a method for contacting a heated roll (hereinafter referred to as a roll heat treatment process), a method of using a spreader, a method of to blow a heated airflow on a roll, etc.

The temperatures for the above heat treatment are set within a range of greater than 1500C to less than 2800C. Temperatures below 1500C are not preferable since there is a possibility that the ACS of the sheet to be obtained is less than
o 50 A, while, on the other hand, if the temperature exceeds 2800C, it becomes difficult to perform the heat treatment by the method described above, since the material of the kind of sheet to be treated tends to lose its shape as a result of the softening .

In addition, although the time for the heat treatment is one of the main factors in determining the crystallinity index, the index may also vary according to the properties of the polymer employed, the processes and the time for the heat treatment and, thus, the adjustment is required so that the crystallinity index falls in the range as previously described
In the following step, in order to obtain the printed circuit board according to the present invention, it is a general practice to apply a metal foil, represented by a copper foil, to the foil material obtained by the process. described above by the use of a suitable adhesive or by using a method for forming a metal chip on the sheet surface by methods such as vacuum coating or metallization, etc., but Alternatively, another method may be employed in which a PPS laminate material and a metal foil are produced by applying the PS to the wire mesh by extrusion or melting the PPS sheet and the foil. ## EQU1 ## after which the PPS laminate is heat treated for crystallization of PPS. feel invention, as described above 1, the failure of: flexibilixé "re Shock" and "ability puncture", which is the inherent disadvantage to non-traditional elongated films
PPS has been substantially improved, and thus the improved sheet-like material with extremely high reliability has been advantageously presented in its applications, for example, to a printed circuit board, this being accompanied by methods of piercing and bending or folding.

 In addition, the printed circuit board according to the present invention is also superior by its electrical characteristics at high frequencies as well as by its resistance to chemicals, its resistance to moisture, its flexibility, its piercing ability and its thermal endurance, and a printed circuit board having various well-balanced features such as that according to the present invention has not yet been conventionally proposed so far.

 Subsequently, description will be given below of the definitions of the characteristic values of the polymer and sheet material used in the present invention and also methods of measurement and evaluation.

(1) Amount of product extracted with chloroform
Approximately 10 g of the sample cut into square pieces, each about 1 cm in length and width, are accurately measured by a chemical scale and the weight is represented by Ag.

 Subsequently, the sample thus measured is placed in a so-called Soxhlet extraction device containing in about 100 cm 3 of chloroform for extraction by a bath of hot water at 650 ° C. for 24 hours.

 Then, the extracted liquid is transferred into a weighing bottle (its weight is represented by Bg), accurately weighed in advance, with subsequent addition of a main washing liquid obtained by washing the inside of the extraction device. by a small amount of chloroform, for subsequent drying in a hot air oven at a temperature of 300C until the liquid disappears.

In the next step, after transfer to the air oven: hot at 650 ° C and drying for one hour, the sample is cooled to ambient temperature in a desiccator containing silica gel and, subsequently, accurately weighed by the balance for chemicals (weight is represented by Cg).

The results thus obtained are applied to the following equation in order to obtain the quantity of product extracted (Wex in% by weight).
Wex = 100 (CB) iA (2) Wide angle X-ray diffraction method OF (orientation factor): each of the samples being aligned in the elongation direction and transformed (for fixing each film during formation a 5 mm collodion solution in amyl acetate) is used in a 1 mm thick, 1 mm wide and 10 nm long strip, the X-rays are directed to be incident. along the surface of the film (in the directions on the edge and at the end to take the photograph of the X-ray image on a plate.For the X-ray production device, the so-called Model unit is used D-3F of the company called Rigaku Denki, the spokes
Ka of Cu being passed through a Ni filter, the conditions of 40 kv-20mA being used for the X-ray source. The distance between the sample and the film was set at 41 m. #, And we adopted a multi-exposure method (38 cm and 30 minutes) by the use of so-called Kodak films, of the screenless type. In the next step, the degree of orientation (OF) for each sample was defined as entant.
OF = I # = 30 / I # = One reads the photodensity of the diffraction peak with indices of
Miller of (200) on plate X-ray image photography, scanning by a dicterometer in a radial direction from the center of the plate image, at the positions of # = On (on the equatorial line), 100, 203, and 08 represents the maximum intensity of the scan at 30, and I # = 0 represents the maximum intensity for the scanning of the equatorial liglis. # = 00 and # = 1800 were used for 9 = 0 and those of the resistance d = 30 and # = and for I # = 300.

 In relation to what has been indicated above, the densitometer measurement conditions are as follows.

 As a device, the so-called Sakura PDM-5 type A microdensitometer model manufactured by the so-called Konishiroku Photo Industry Co. was used, the range of measurement densities of 0.0 - 4, OD (minimum conversion of measurement for a surface of 4), optical magnifications of 100 times, slit width of 1 and a height of 100, while the speed of movement of the film is 50 p / s for an abacus speed of 1 mm / s.

 ACS (apparent crystal size) and crystallinity index: to cancel the orientation effect of the sample, the method of rotating the sample in a plane was adopted and the diffraction pattern was measured by the method of refraction. As a device for producing X-rays, the so-called Model D-8C unit manufactured by the company called Rigaku Denki was used, whereas the Cu Ka radiation that was passed through the Ni filter under the conditions of FIG. 35 kV - 15 mA was used as an X-ray source. For the goniometer, the so-called PMG-A2 model unit manufactured by Rigaku Denki was used, and the sample was mounted on a rotary table for sample , which can be rotated at a speed of 80 rpm, a divergence slot of 10, a receiving slot of 0.15 mm and a scattering slot (dispersion) of 10 being used for the slit system . The sweep rate of 20 was 1 / minS while the speed of the chart was 1 cm / min. Each of the samples was cut into a square having a 20 min side and was stacked to a thickness of 0.5 mm to prepare the measurement sample.

From the half-width of the Miller index diffraction peak of (200), the apparent crystal size (ACS) was obtained using the Scheller formula: ACS () = k # / sscos #, ss = [B = K / S cosO (,) 2] (B ') 1/2
where K: Scheller constant (K = 1)
wavelength of the X-rays (R = 1, 5418
20: Bragg angle (o)
half width after correction (radian)
B: half width measured in fact
B ': half width standard corrected sample
(Si monocrystal)
In addition, relative to the crystallinity index obtained from the diffraction pattern of each sample, the maximum intensity (I 2 U) for the Miller index diffraction peak of (200) and the intensity (125) for . 2 # = 25, as internal standard, were measured, the ratio between them being defined as the crystallinity index (I2oo / 125) (3) Apparent melt viscosity (p0) and non-Newtonian coefficient (N) ).

Using an extrusion plastometer viscometer having a capillary-shaped matrix of length
L and of radius R, when the production (yield) in volume, during the extrusion of the polymer under pressure P and at temperature T, is represented by Q, the shear stress
o Apparent T, the apparent shear rate y and the apparent viscosity are defined as follows
TJ (RP) / (2L)
# = (4 #) / ([# R)
= T /
In the case above, the apparent melt viscosity po is defined by the value, for # = 200 (s) 1, of a
o curve p = f (y). to obtain by taking p, at the indicated time, with respect to various values of #.

On the other hand, the non-Newtonian coeffieient N is defined by the inverse of the value, for oy = 200 {s), of
o D
d log g (#) g (y) / d loq # which is the complete logarithmic differential function of a curve T = g (#) to obtain while carrying T with respect to various values of i. Its value N, as described above, is equal to index n, assuming that the relationship between the shear stress S and the shear rate D of the polymer at the melt eta (called flow curve) can be provided approximately by the formula D = aSn (a and n are constants).

In the present invention, the measured value for
T = 3000C was adopted using a matrix having a length L of 10 mm and a radius R of 0.5 mm.

(4) Glass transition temperature (Tv) and
melting point (Tf).

These values were measured by the so-called
DSC, then Tf was defined by the maximum temperature (peak temperature) of the melting curve.

(5) Tensile strength and elongation
According to the method presented in JIS 1702, the measurements were taken using an experimental tensile device of the "Instron" type.

(6) Thermal contraction
A. Cut the sample film into ribbon-like form,
each ribbon measuring 10 mm wide and 250 mm long
LATIONS.

B. Two marked lines are drawn in the direction transver
dirty in a parallel relationship to each other, to a
interval of about 200 mm, and one measures accurately
the interval between the marked lines by using a dis
positive says casedometer (range designated by A mm).

C. Place the above sample in a hot air oven
at 250 C, a charge of 1 g being applied to the front of the
the sample, and remove the sample after having
let stand in the oven for 10 minutes.

D. We measure the interval between the two marked lines of
again using the casedometer (designated interval
by B mm).

E. The thermal contraction (o) is defined by the expression
100 (AB) / A.

(7) Folding endurance
The endurance value at 200C folding was measured
according to the process presented in JIS P-8115 (process known as
MIT).

(8) Defects rate in the drilling process
A. In the case of a sheet
The sheet being cut in a strip form
with a width of 35 mm and a length of 10 m,
pinion teeth perforations of the carrier tape
for so-called thin slices IC are formed on the
opposite sides of the strip, using a machine
perforation for the carrier strips for the
thin slices called IC. Ensult, counting the name
of perforations formed with cracks on the
peripheral edges, by visual inspection, the rate of die
defects in the piercing process is defined by the
rate relative to the total number of perforations.

B.In the case of a printed circuit board substrate
Using a drill of 1 mm in diameter, 1,000
holes or bores are formed in the substrate to by
shot from the metal foil side, following a configura
of the checkerboard type, at intervals of 10 mm, and in
the number of holes with cracks on their
peripheral edges is counted by visual inspection so
to define the defect rate during the piercing process
the rate in relation to the total number of holes.

(9) Welding ability
A.In the case of a sheet
The film cut into squares having 50 mm in length and
width is floated on a hand solder bath
kept at a temperature of 250 C for the observation of
Dimensional stability at this time. Then we
applies a voltage of approximately 0.5 kg / mm,
at the opposite edges of the film in the solder bath, for
the visual examination of the degree of elongation at this moment.

The results of the evaluation are represented by the
four following signs
g: the dimensional stability is favorable,
almost without lengthening.

although favorable in terms of stability
dimenslonnelle, the lengthening is important
: the elongation is weak but bad stabi
dimensional dimensionality
X: poor dimensional stability, with large
elongation
B. In the case of a circuit board substrate im
premium
The evaluation is carried out according to the presented process
in JIS C-6481, and the swelling and peeling at the
film surface and on the surface of the copper foil
were visually examined.

The results of the evaluation were represented by the following signs
0: neither the swelling nor the coat is remarkable
X: both swelling and peeling are
outstanding (10) Resistance to chemicals
The evaluation was carried out according to the method presented in IPC (Institute of Printed Circuits) Test Methods Manual No. 2, 3, 2, and the indications were provided as follows according to the residual rate or retention of resistance to the peel removal.

0: Residual rate over 80 aj inclusively
X: Residual rate less than 80
Below, examples are given for the purpose of explaining the present invention without any limitation.

EXAMPLE 1
(1) Polymerization of PPS
A. Polymerization of High Molecular Weight PPS (Presented as PPS-A) Used in the Present Invention
32.6 kg of sodium sulfide (250 moles, containing 40% by weight of water of crystallization), 100 g of sodium hydroxide, 18.0 kg (125 moles) of sodium benzoate and 79.2 kg of N-methyl 2-pyrrolidone (hereinafter referred to as NMP) were placed in an autoclave, and, little by little, the temperature was increased to 250 ° C. while stirring in order to remove the distillation liquid in an amount of 7%. Containing 37.5 kg (255 moles) of 1,4-dichlorobenzene (hereinafter referred to as DCB) and 20.0 kg of NMP were added to the remaining mixture to heating at 251: OC for 3 hours.

The reaction product was stripped in methylene chloride at 380C for 2 hours, washed 8 times in hot water, and then dried at 800C for 24 hours using a vacuum drying device; thus, 21.9 kg of high molecular weight PPS (81% yield), with apparent melt viscosity of 4,200 poises, N value of 1.6, Tg of 910C and Tf of 280 ° C were obtained. .

B. Polymerization of PPS (designated PPS-B) as a com
parison
In the procedures similar to that described above, the polymerization was carried out for 5 hours at 2650C with 8-fold washing with hot water, without extraction with methylene chloride, and with subsequent drying. thus, approximately 20 kg of dried PPS having an apparent melt viscosity of 3,500 poises, an N value of 1.6, a Tg value of 88 C and a Tf value of 279 C were obtained.

(2) Thermoforming
PPS-A and PPS-B, obtained by the processes as described in (1) above, were each sent to a 40 mm diameter extruder and melted at a temperature of 3100C, then extruded from a T-die having a linear lip length of 600 mm and a clearance of 0.2 mm, to be cast on a metal drum maintained at a surface temperature of 650C for cooling and solidification; thus, amorphous films A1 and B1 with a width of 550 mm and a thickness of 50 μm have been obtained (method of rolling). In addition, PPS-A and PPS-B were each supplied to a 38 mm diameter extruder for melting at a temperature of 310 ° C, and then extruded from a 50 mm circular die. diameter and 0.5 mm clearance. Immediately after, air is directed into the tube of molten film for blowing 10 times on its supersurface, for subsequent rapid cooling by a stream of air; thus, amorphous films A-2 and B-2 having a width of 250 mm and a thickness of 50 μm (tube process) were obtained.

(3) Heat treatment
The amorphous films Al, A-2, B1 and B-2 were subjected to the heat treatment by employing a broadening only at 2600 C for 30 seconds, and thus All, A-2-1 films were obtained. Bll and 8-2-1.

(4) Properties of the obtained films
Table I shows the properties of the films obtained. More specifically, the films All and A-2-1 are those according to the present invention, while the films 8-1-1 and 8-2-1 are films other than those according to the present invention.

TABLE I

<tb> symbols <SEP><SEP> MUS <SEP><SEP> Quanti- <SEP><SEP> U # <SEP><SEP>(<SEP>Factor><SEP> ACS <SEP><SEP> (di- <SEP><SEP> Index
<tb> of <SEP> movie <SEP> em- <SEP><SEP> ex <SEP><sep>SEP>
<tb><SEP> folded <SEP> treats <SEP> A <SEP> tra- <SEP> A <SEP> the former <SEP> On <SEP><SEP> apparent <SEP><SEP> screams
<tb><SEP> at <SEP> at <SEP> trem <SEP> at <SEP> at <SEP> at <SEP> talli
<tb><SEP> chloro- <SEP> cris- <SEP> nity
<tb><SEP> form <SEP> tiux) <SEP>
<tb><SEP> (t <SEP> in <SEP> (A) <SEP>
<tb><SEP> weight) <SEP>. <SEP>
<Tb>

All <SEP> A <SEP> 0.71 <SEP> 0.89 <SEP> 0.94 <SEP> 0.91 <SEP> 72 <SEP> 5.1
<tb> A-2-1 <SEP> A <SEP> 0.69 <SEP> 0.95 <SEP> 0.80 <SEP> 0.79 <SEP> 70 <SEP> 5.4
<tb> B11 <SEP> B <SEP> 1.98 <SEP> 0.90 <SEP> 0.96 <SEP> 0.89 <SEP> 73 <SEP> 5.5
<tb> 8-2-1 <SEP><SEP> B <SEP> 1.95 <SEP> 0.96 <SEP> 0.81 <SEP> 0.82 <SEP> 74 <SEP> 5.7
<tb> (5) Rating
The table shows the evaluation results of the films described above.

 As it is clear from Table II, the films according to the present invention are superior not only in their mechanical properties and their dimensional stability at high temperatures, but also in the flexibility and piercing ability which have been connected. the disadvantages of conventional films, while having less degradation of flexibility and piercing ability as a function of time. On the other hand, known films having a large amount of chloroform extract product exhibit poor flexibility and poor piercing ability.

TABLE II

<tb> Sample
<tb><SEP> of <SEP> film <SEP> All <SEP> A-2-1 <SEP> Bll <SEP> B-2-1
<tb> Results
<tb> evaluation
<tb> Resistance <SEP> to <SEP> the <SEP> pull
<tb> (kg / mm2) <SEP> (Direction <SEP> from <SEP> la
<tb> machine) <SEP> 8.0 <SEP> 8.5 <SEP> 7.8 <SEP> 8.1
<tb> Lengthening <SEP> (D) <SEP> (Direction
<tb> of <SEP> the <SEP> machine <SEP> 7 <SEP> 4 <SEP> 7 <SEP> 1 <SEP> 6 <SEP> 5 <SEP> 6 <SEP> 6
<tb> Contraction <SEP> thermal <SEP> (%)
<tb> (SEP <SEP> Direction) <SEP><SEP> o, <SEP> 4 <SEP> 0.5 <SEP> o, <SEP> 5 <SEP> 0.5
<tb> Stamina <SEP> Immediately
<tb> at <SEP> folding <SEP> after <SEP> the <SEP>
<tb> (number <SEP> brication <SEP> 5200 <SEP> ~ <SEP> -6500 <SEP> 900 <SEP> 1300
<tb><SEP> times <SEP> 100 C, <SEP> after
<tb><SEP> 30 <SEP> bears <SEP> 3600 <SEQ> 4300 <SEQ> 440 <SEQ> 670
<tb><SEP><SEP> Rate Immediately
<tb> defects <SEP> after <SEP> the <SEP> fa
<tb> in <SEP><SEP> manufacturing <SEP> D <SEP> 0 <SEP> 1.3 <SEP> 0.9
<tb> process <SEP> i1309C, <SEP> after
<tb> of <SEP> pers <SEP> 30 <SEP> days <SEP> O <SEP> 0 <SEP> 1.7 <SEP> 1.5
<tb> cement
<tb> (point
<tb> çonnaqe)
<tb> Notes <SEP> iPresen- <SEP> Presents <SEP> Arti <SEP> Arti
<tb><SEP><SEP><SEP><SEP><SEP>
<tb><SEP> vention <SEP> vention <SEP> compa- <SEP> compa
<tb><SEP> ratif <SEP> ratify
<Tb>
EXAMPLE 2 (1) amorphous film
The amorphous film A-1 used in Example 1 was used.

(9d Heat treatment
The amorphous film A-1 was subjected to heat treatments at various temperatures for different periods of time using the wiper, and thus All-to-1-5 films having different crystallinity and different ACS (apparent dimensions of the crystals).

(3) Properties and evaluation results of the films obtained
Table III shows the properties and evaluation results of the resulting films.

 In Table III, it is indicated that, even though the amount of product extracted with chloroform is low, films with higher properties are difficult to obtain, since the three sets of parameters during wide-angle X-ray diffraction are not included in the specific range.

TABLE III

<tb> Article <SEP> Unit <SEP> All <SEP> A-1-2 <SEP> A-1-3 <SEP> Al-4 <SEP> A-1- <SEP>
<tb> Temperature <SEP> of <SEP> treats
<tb> ment <SEP> thermal <SEP> 00 <SEP> 260 <SEP> 260 <SEP> 277 <SEP> 130 <SEP> 270
<tb> Time <SEP> of <SEP> Processing <SEP> Se
<tb> thermal <SEP> count <SEP> 30 <SEP> 2 <SEP> 3600 <SEP> 30 <SEP> 60
<tb> Quantity <SEP> of <SEP> product <SEP> Ó <SEP><SEP> in
<tb> extract <SEP> with <SEP> chloro- <SEP> weight
<tb> form <SEP> 0.71 <SEP> 1.1 <SEP> 0.62 <SEP> 1.0 <SEP> 0.69
<tb> or <SEP><SEP> (factor <SEP> of orien
<tb><SEP> tation)
<tb><SEP> A <SEP> through <SEP> 0.89 <SEP> 0.87 <SEP> 0.85 <SEP> 0.95 <SEP> 0.87
<tb><SEP> A <SEP> the end <SEP> 0.94 <SEP> 0.96 <SEP> 0.98 <SEP> 1.00 <SEP> 0.96
<tb><SEP> On <SEP> the <SEP> edge <SEP> 0.91 <SEP> 0.88 <SEP> 0.84 <SEP> 0.97 <SEP> 0.90
<tb> ACS <SEP> (dimension <SEP> appa
<tb><SEP> rent <SEP> of <SEP> crystals) <SEP> A <SEP> 72 <SEP> 69 <SEP> 80 <SE> 45 <SEP> 45
<tb><SEP> Index of <SEP> crystallized
<tb> nity <SEP> 51 <SEP><SEP> 20 <SEP><SEP> 85 <SEP><SEP> 25 <SEP><SEP> 53 <SEP>
<tb> Rate <SEP> of <SEP> contraction
<tb> thermal <SEP> 0.4 <SEP> 0.8 <SEP> 0.3 <SEP> 0.7 <SEP> 0.4
<tb> Stamina <SEP> at <SEP> folding
<tb> (immediately <SEP> after <SEP> the
<tb> manufacturing) <SEP> 5200 <SEP> 8300 <SEP> 240 <SEQ> 2600 <SEQ> 4900
<tb> Suitability <SEP> to <SEP><SEP> welding <SEP> o <SEP> x <SEP> -1 <SEP><SEP> o <SEP> x <SEP> o
<tb> Notes <SEP> Pre- <SEP> Arti- <SEP> Arti <SEP> Arti
<tb><SEP> feels <SEP> key <SEP> key <SEP> key
<tb><SEP><SEP> com <SEP> com <SEP> com
<tb><SEP> ven- <SEP> para- <SEP> para- <SEP> para
<tb><SEP> tion <SEP> tif <SEP> tif <SEP> tif
<Tb>
EXAMPLE 3 (1) Raw material
PPS-A used in Example 1 was used.

(2) Thermoforming
PPS-A was formed by the tube process in point (2) of Example 1. In the above case three kinds of matrices prepared by bringing the slots of circular dies respectively to a value of 0 , 4 mm, 0.8 mm and 2.5 mm were used, with insufflation 8 times, 16 times and 50 times in the respective surfaces, and thus three kinds of films (designated A-3,
A-4 and A-5) each having 50 μm thickness.

(3) Heat treatment
Amorphous films A-3, A-4 and A-5 were respectively heat-treated using the wiper at 2700C for 120 seconds, and thus A-3-1, A- films were obtained. 4-1 and A-5-1.

(4) Properties and evaluation results of films obtained
Table IV shows the properties and the evaluation results of the resulting films.

 In Table IV, it is indicated that in films with a low orientation factor the thermal contraction is increased by the residual deformation due to the orientation, and thus the higher characteristics as in the non-elongated films are lost. undesirable way.

TABLE IV

Sample <tb><SEP> Fili # <SEP>
<tb> Articles <SEP> ~~~~~~~~~~~~~~~~~~~~~~~~
<tb> Quantity <SEP> of <SEP> product <SEP> extract <SEP> at
<tb> chloroform <SEP> (DA <SEP> in <SEP> weight)
<tb> OF <SEP> (Orientation Factor <SEP>)
<tb><SEP> A <SEP> through
<tb><SEP> A <SEP> the end <SEP> z <SEP> 0.86 <SEP> 0.76 <SEP> 0.61
<tb><SEP> On <SEP> the <SEP> edge <SEP> 0.85 <SEP> 0.75 <SEP> 10.59
<tb> ACS <SEP> (apparent <SEP> dimension <SEP> of <SEP> crystals) <SEP> 76 <SEP> 75 <SEP> 72
<tb> index <SEP> of <SEP> stallinity
<tb> Rate <SEP> of <SEP> contraction <SEP> thermal <SEP> (Dt) <SEP> 0.3 <SEP> 0.5 <SEP> 31.6
<tb> Stamina <SEP> at <SEP> folding <SEP> (number <SEP> of
<tb> times)
<tb> Aptitude <SEP> to <SEP> the <SEP> weld <SEP> o <SEP> o
<tb> Presen <SEP> Presen <SEP> Presen
<tb><SEP><SEP><SEP><SEP><SEP> in <SEP>
<tb><SEP> Fri- <SEP> Fri- <SEP> Fri
<tb><SEP> tion <SEP> tion <SEP> tion
<Tb>
EXAMPLE 4 (1) Base film
The PPS (All) film according to the present invention and the comparative film (B11) employed in Example 1 were used.

(2) Preparation of a printed circuit board substrate
at. In the first place, the base film was submitted to a
electric crown treatment by applying
electrical energy at the rate of 3000 joules per 2
m of film.

b. Subsequently, a mainly composed adhesive
of a polyamide of the group of dimer acids (product
said "Milbex 1200") was coated to a thickness of
(After drying) using a
reverse coating (reverse coating).

c. In the next step, with a polished Cu sheet
electrolytically (thickness of 35 μm) for subs
Trades of printed circuit boards stacked by
above, the film was passed through a roll
compression having a linear pressure of 3 kg / cm,
and kept at a temperature of 1000C for the
stratification.

d. The layered material thus obtained was left
rest in a hot air oven at 800C for 4 days,
in order to harden the adhesive, and thus, the
substrate for a printed circuit board.

(3) Evaluation results
Table V presents the results of the evaluation.

In Table V, it is indicated that, in the printed circuit substrate, according to the present invention, the piercing ability, which is related to the disadvantages of conventional substrates employing known non-elongated PPS films, has been improved, while the superior chemical resistance and thermal endurance specific to substrates using PPS films are sufficiently maintained.
TABLE V

<tb><SEP> Movie <SEP> ~~~ <SEP>} 1 <SEP> of <SEP> base <SEP> All <SEP> 8-1-1
<tb> Su <SEP> and <SEP> Evaluation
<tb><SEP> rate of <SEP><SEP> defects in <SEP><SEP> process
<tb> of <SEP> piercing <SEP>(<SEP> piercing) <SEP> O <SEP> j <SEP> 2.1
<tb> Resistance <SEP> to <SEP> products <SEP> chemi
<tb> ques
<tb><SEP> Alcohol <SEP> o <SEP> I
<tb><SEP> Hydrocarbon <SEP> o <SEP> o
<tb><SEP> Ketone <SEP> o <SEP> o
<tb><SEP> Product <SEP> Chlorinated <SEP> o <SEP> o
<tb><SEP> Solvent <SEP> o <SEP> o
<tb><SEP> Acids <SEP> o <SEP> o
<tb><SEP> Base <SEP> - <SEP> o
<tb> Aptitude <SEP> to <SEP> the <SEP> weld <SEP> o <SEP> o
<Tb>
The appreciation of some of the measurement values indicated above must take into account the fact that they come from the conversion of imperial units into metric units.

 The present invention is not limited to the embodiments which have just been described, it is instead capable of modifications and variants that will occur to those skilled in the art.

Claims (2)

 1 - Sheet-like material comprising a composition consisting mainly of high molecular weight poly (p-phenylene sulfide), characterized in that  (a) the amount of product extracted by chloroform extraction is less than 1.5% by weight relative to the total weight before extraction; and  (b) i. the crystallinity index is in the range of values greater than 2.5 and less than 8.0;  ii. the size of the crystallites is in the  o range of values greater than 50 A and less than 100 A; and  iii. the orientation factors measured in three directions across, at the edge and at the end are respectively greater than 0.70, as measured by the wide-angle X-ray diffraction method.  2 - Printed circuit board, characterized in that it comprises the sheet material of poly (p-phenylene sulfide), as indicated in claim 1, and a thin metal film laminated thereon.