JPS62273792A - Printed wiring board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention provides a printed wiring that has excellent heat resistance dimensional stability, solder heat resistance, and moisture resistance dimensional stability, and is lightweight, thin, and inexpensive. Regarding boards (including flexible printed wiring boards).

<Prior Art> In recent years, there has been a remarkable trend toward smaller size, lighter weight, and higher performance of electrical and electronic products such as cameras, calculators, watches, and computers. The miniaturization, weight reduction, and high performance of these electrical and electronic products are mainly due to advances in semiconductor elements, such as transistors, ICs, and L
SI is becoming more and more highly integrated into ultra-LSI.

As these semiconductors become more highly integrated, printed wiring boards become narrower in conductor width and conductor gaps, or multilayered.

High density is rapidly progressing due to surface mounting and flexibility. Furthermore, there has been progress from single-sided boards to double-sided boards, from through-hole double-sided boards to multilayer boards, and from flexible printed wiring boards. The insulating base materials for these wiring boards include paper/phenol resin-based PP material, paper/epoxy resin-based PE material.

Insulating materials such as glass cloth/epoxy resin based GE materials have been developed. Among these materials, PP material.

PE materials are used in printed wiring boards for household electronic devices such as color televisions and radios because they are cheap, easy to process, and suitable for mass production. However, P.E.
The material is heat resistant and dimensionally stable.

Moisture dimensional stability is insufficient. In addition, GE materials have excellent mechanical strength, electrical properties, heat resistance, water resistance, and moisture resistance, so ICs require a high degree of reliability.

It is used as a substrate for LSIs and printed wiring boards for electronic devices such as computers, electronic exchanges, and various measuring instruments.

However, the current situation is that GE materials cannot sufficiently respond to the remarkable progress in LSI, and GE materials have the following problems. (1) Poor mechanical properties at high temperatures (2) Mechanical properties due to long-term use at high temperatures.

Significant deterioration of electrical properties (3) Large dimensional change at high temperatures. Therefore, GE materials have poor reproducibility of original dimensions, making it difficult to manufacture high-precision circuits, and have limitations in their use in printed wiring boards for high-density circuits. Furthermore, the temperature linear expansion coefficient is large, making it difficult to mount semiconductor components. Moreover, the productivity of the glass cloth itself is poor. In particular, when trying to make glass cloth that is thin and has a low basis weight, the weavability deteriorates and productivity further decreases, so there is a limit to how low the fabric weight can be made. In addition, the woven fabric itself has a drawback in that it has good strength and one-dimensional stability in the warp and cross directions, but is poor in the diagonal direction.

Furthermore, since it is heavy and thick, if it is multi-layered, the volume becomes large and it becomes heavy. Furthermore, since it is not flexible, it is unsuitable as a material for flexible printed wiring boards.

Single-layer ceramic materials and metal materials have excellent soldering heat resistance, heat-resistant dimensional stability, moisture-resistant dimensional stability, etc., but have the disadvantage that they become extremely heavy when multilayered. Furthermore, ceramic materials have poor flexibility and are unsuitable for flexible printed wiring boards. Metal materials have a large temperature linear expansion coefficient, making them unsuitable for mounting semiconductor components or printed wiring boards for high-density circuits.

-H Insulating base materials for flexible printed wiring boards are mainly polyester films, polyimide films (registered trademark Kabu1-N: manufactured by DuPont), glass fiber cloth impregnated with a flexible resin, or fully scented polyamide paper. (
Registered trademark NOmeX (manufactured by DuPont), etc. are used. Polyester film is inexpensive and has excellent flexibility, but is easily flammable and has poor solder heat resistance and heat-resistant dimensional stability. Polyimide films have excellent flexibility and soldering heat resistance, but are highly hygroscopic, have poor heat-resistant dimensional stability and moisture-resistant dimensional stability, and are extremely expensive. On the other hand, a material made of glass fiber cloth impregnated with a flexible resin, which is excellent in solder heat resistance, good moisture resistance dimensional stability, and is inexpensive, is being used as an insulating base material for flexible printed wiring boards. This film has intermediate performance between polynisdel film and polyimide film, but as a result of the remaining rigidity of the glass fiber itself, it has the drawbacks of poor flexibility and folding durability, as well as being heavy and thick. be. Furthermore, since the flexible resin has a large heat shrinkage rate, heat residual shrinkage rate, and temperature linear expansion coefficient, glass fiber cloth is affected by this and does not have good heat-resistant dimensional stability.

In addition, fully aromatic polyamide paper (registered trademark Homex, manufactured by DuPont) has come into use in some cases, but N
Omex■Paper has good flexibility and is less expensive than polyimide film, but it is resistant to soldering heat.

It has poor heat resistance and dimensional stability, and is also highly hygroscopic and has poor moisture resistance and dimensional stability. Solder heat resistance is hygroscopic (equilibrium moisture content),
There is a close causal relationship with heat resistant dimensional stability. In other words, the phenomenon of blistering, peeling, or curling between the conductor and the base material in the solder heat resistance test is due to the equilibrium moisture content and heat-resistant dimensional stability (heat shrinkage rate, heat residual shrinkage rate, temperature linear expansion coefficient) This can be explained by: In the solder heat resistance test, when the temperature of the paper layer rises rapidly on a solder bath exceeding 260℃, water rapidly evaporates and passes between the paper layers and scatters into the outside air, but if the equilibrium moisture content is high, This amount of water vapor is large. As a result, a large amount of high-pressure water vapor is blocked between the paper layers, causing blistering and peeling. Further, if the temperature linear expansion coefficient or heat shrinkage rate is large, large curls will occur on the solder bath, and if the residual heat shrinkage rate is large, curls will remain even after cooling to room temperature after the solder heat resistance test.

When using Nomex ■ paper, in order to eliminate blistering, peeling, and curling, it is thoroughly dried or heat-treated to remove distortion, and then soldered before re-absorbing moisture. However, not only is the process complicated, but it is also very easy to reabsorb moisture even after drying, making it difficult to completely prevent blistering, peeling, and curling.

Various materials have been studied to compensate for the drawbacks of these base materials. For example, Japanese Patent Publication No. 52-27189 discloses the use of Sea 1~, which is a nonwoven fabric made of aromatic polyamide fibers and polyester fibers impregnated with a resin, as a base material.

When used as a mixture of aromatic polyamide fibers and polyester fibers under optimal blending conditions, this sheet has a smaller thermal expansion coefficient at 30 to 160°C and lower hygroscopicity than Nomex paper, making it easier to use in the soldering process. It is stated that no blistering, peeling, or curling occurs. However, since the sheet contains polyester fibers, even if it is coated with a thermosetting resin, the polyester fibers substantially soften and melt during the soldering process, resulting in insufficient solder heat resistance and heat-resistant dimensional stability.

Furthermore, Japanese Patent Publication No. 56-1792 discloses the use of a resin-impregnated sheet of nonwoven fabric made of aromatic polyamide fibers, acrylic fibers, and stretched polyester fibers as an insulating base material. 52-27
Similar to the sheet of Publication No. 189, it contains polyester fibers and is coated with a thermosetting resin, but the polyester fibers are substantially softened and melted during the soldering process, so the soldering heat resistance and heat resistance X1 method are stable. inferior in sex.

Furthermore, JP-A-60-126400 also discloses a paper-like product obtained by wet-processing a slurry of aromatic polyamide fibers and polyester fibers and then heat-pressing the slurry, which can be applied to flexible printed wiring boards. However, as mentioned above, it is difficult to achieve sufficient solder heat resistance and heat-resistant dimensional stability due to the inclusion of polynisder fibers.

Furthermore, Japanese Patent Application Laid-Open No. 60-230312 discloses a flexible printed wiring board whose insulating base material is Sea 1, which is a nonwoven fabric or paper containing aramid fibers as a main component and impregnated with a resin containing diallyl phthalate resin as a main component. Disclosed.

Furthermore, JP-A No. 60-260626 discloses a sheet in which an aramid nonwoven fabric is impregnated with a resin and has a specific ratio of weight, apparent density, tensile strength in the machine direction/tensile strength in the transverse direction. .

Further, Japanese Patent Publication No. 60-52937 discloses a copper-clad laminate using a sheet made of an aromatic polyamide fiber cloth coated or impregnated with an epoxy resin and/or polyimide resin and dried.

However, until now, there are no known base materials for printed wiring boards that are excellent in solder heat resistance, have a temperature linear expansion coefficient as low as that of semiconductor components, and are fully compatible with surface mounting, have good moisture resistance and dimensional stability, and are lightweight and inexpensive. It has not been done.

OBJECTS OF THE INVENTION The present invention overcomes the drawbacks of conventional substrates made of resin-impregnated films, paper, fiber cloth, and nonwoven fabrics.

In other words, it has excellent solder heat resistance and has a temperature linear expansion coefficient as small as that of semiconductor components, so when used as a printed wiring board, cracks will not occur in the solder joints due to the heat cycle that occurs with surface mounting of semiconductor components. There is no. Furthermore, it is an object of the present invention to provide a paper-like material having excellent heat-resistant and dimensional stability, in which a high-density circuit does not undergo dimensional changes due to expansion and contraction, resulting in circuit defects. In addition, it has a low coefficient of linear expansion in humidity, so there is little curling at high humidity, and it has excellent moisture resistance and dimensional stability, which does not cause dimensional changes in high-density circuits due to expansion or contraction, resulting in circuit defects. A paper-like material that is thin, has a small volume even when multi-layered, and is light, and has excellent flexibility even when used as a single layer, so it can be used as a base material or coverlay for flexible printed wiring boards. This is what we intend to provide.

<Structure of the Invention> The printed wiring board of the present invention includes wholly aromatic polyetheramide short fibers and meta-based wholly aromatic polyamide pulp,
Temperature linear expansion coefficient (αT) is -20×10-6/℃≦α,
≦20x 10-6/''C, and a sheet made of a paper-like material and a resin is used as a base material or a coverlay.

The wholly aromatic polyether amide short fibers referred to herein are high modulus wholly aromatic polyether amide copolymers composed of the following repeating units (I>), which are fully stretched and highly molecularly oriented. These are etheramide copolymer fibers and/or short fibers obtained by crushing and fibrillating the fibers.

This short material is flame retardant, has large O and I values, has good adhesion to resin, and has excellent heat resistance.

Furthermore, the equilibrium moisture content, heat shrinkage rate, and heat residual shrinkage rate are small. What is also noteworthy is that the temperature linear expansion coefficient takes a negative value. These properties are extremely unique among full-strength polyamide short fibers, and they provide excellent heat and moisture resistance dimensional stability, especially when compared with polymetaphenylene isophthalamide short fibers.

The single fiber fineness of wholly aromatic polyetheramide short fibers is 0.1
-10 de, preferably 0.3-5 de. 09
Below lde, there are many difficulties in spinning technology (thread breakage).

occurrence of fuzz, etc.). On the other hand, if it exceeds 10 de, it becomes impractical in terms of mechanical properties.

Further, the length of the wholly aromatic polyetheramide staple fiber is preferably 1 to 60 mm, more preferably 3 to 40 mm. If the cut length is too small, the mechanical properties of the paper-like material obtained will deteriorate, and if the cut length is too large, the paper-like material will have poor formation and its mechanical properties will also deteriorate.

Furthermore, wholly aromatic polyT-tylamide short fibers are easily fibrillated by mechanical shearing force. By fibrillating, it is possible to produce short fibers with a fineness that is difficult to spin.Using fibrillated short fibers improves the texture of paper-like products and makes them of excellent quality.

In the present invention, a meta-based wholly aromatic polyamide composed of the following repeating unit (II) is used as a binder material for the wholly aromatic polyetheramide short fibers.

Specifically, they include poly(metaphenylene isophthalamide) and poly(metaphenylene isophthalamide terephthalamide) copolymers. The meta-based wholly aromatic polyamide preferably has an intrinsic viscosity (ηinh) of 0.7 or more. The intrinsic viscosity (ηinh) is 0.5g/100
This is a value measured at 30°C using an N-methylpyrrolidone solution of rd.

When producing pulp from a meta-based wholly aromatic polyamide solution, for example, the method described in Japanese Patent Publication No. 35-11851 is used. That is, a polymer solution is introduced into a solvent that is compatible with the solvent constituting the polymer but incompatible with the polymer while stirring at high speed, and the polymer is precipitated while applying a shearing force. In this case, the manufacturing apparatus described in Japanese Patent Publication No. 36-40479 and Japanese Patent Application Laid-Open No. 52-15621 can be used. In addition to water, alcohol, glycol, glycerin, etc., an aqueous solution of a calcium chloride aqueous solution and a dipolymer solvent can be used as the non-solvent to precipitate the pulp.

For example, in the case of polymetaphenylene isophthalamide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. are used as a solvent, but in this case, it is preferable to use an aqueous solution of these as a nonsolvent.

In addition, inorganic salts (
For example, it is preferable that lithium chloride, calcium chloride, etc.) remain as little as possible.

For example, a homo mixer, a working mixer, etc. are used as the apparatus for producing pulp. Further, this stirring is not limited to the rotary mixing type, but may also be performed by, for example, a T-shaped line mixer or a rotary line mixer. Furthermore, special public Sho 3B-40
It is also preferable to use the equipment shown in Publication No. 479@ or Japanese Unexamined Patent Publication No. 15621/1983. When these devices are used, the specific surface area of the pulp is generally increased, and as a result, the mechanical properties of the paper-like material, such as tensile strength, tear strength, and elongation at break, are improved. The specific surface area here is the surface area per unit mass. The resulting pulp is fully usable as is, but may be reprocessed if necessary. For example, the pulp is subjected to a treatment such as beating, which is carried out prior to papermaking in general paper manufacturing. By performing such a treatment, the specific surface area of the pulp is generally increased, and as a result, the mechanical properties of the paper-like product are improved.

A paper-like material composed of short fibers and pulp can be obtained by a conventionally known method.

That is, the dry method using a card or air lay method (such as land univer), the wet method using a paper machine, etc. are preferred, but the wet method is preferable in order to obtain a paper-like material with a uniform and good texture.

In the wet method, paper can be made by dispersing and/or beating the pulp into a dilute slurry and then dispersing short fibers therein, or by dispersing and disintegrating both at the same time, or by performing necessary pretreatments such as further beating. preferable. A conventional paper machine is used for paper making. Paper can be made by hand, but industrially it can be made using a fourdrinier paper machine, a short wire paper machine, a cylinder paper machine, a rotary paper machine, etc.

If the amount of pulp in the slurry is small, the mechanical properties of the paper-like product obtained will deteriorate. On the other hand, if there is too much pulp, the mechanical properties of the paper-like product obtained will deteriorate. In general, the content of polyvalent phenylene terephthalamide short fibers is preferably 5 to 95% by weight, preferably 20 to 80% by weight, and the content of pulp is 95 to 5% by weight, preferably 80 to 20% by weight.

The paper-like material is subjected to heat and pressure treatment as necessary. For example, when calendering is performed, the surface temperature of the calender roll is 2
Preferably, the temperature is 50° C. or higher and the pressure is 50 kMCI or higher.

When forming a paper-like product, the repeating unit (II) serves as a binder for the wholly aromatic polyetheramide short fibers.
In addition to pulp composed of thermoplastic heat-resistant polymer fibrous binders (polyester such as polyethylene prephthalate, polyamide such as 6°6-nylon, polysulfone) as necessary.

polyphenylene sulfide, etc.). In the wet method, water-dispersible binders, powdered binders, etc. can also be used.

On the other hand, other short fibers other than wholly aromatic polyether amide short fibers and meta-based wholly aromatic polyamide pulp, such as glass short fibers, ceramic short fibers, carbon fibers, fully aromatic polyester short fibers, polyether ether ketone short fibers, etc. Heat-resistant fibers such as fibers can be included as long as the purpose of the invention is not impaired.

The paper-like material containing wholly aromatic polyetheramide short fibers and meta-based wholly aromatic polyamide pulp in the present invention has a basis weight of 10 to 300 (+/Td, preferably 15 to 250 (
It/m. If the basis weight is less than 109/m, the formation will deteriorate and the uniformity of the resulting paper-like material will be poor.

On the other hand, if the basis weight exceeds 300 Myd, papermaking becomes difficult.

The printed wiring board in the present invention has a temperature linear expansion coefficient (α
) is -20X 10-6 /℃≦αT≦20X10-6
It is characterized by using a paper-like material whose temperature is /℃. The temperature linear expansion coefficient (αT) referred to here refers to the thermomechanical analyzer (TM)
A) is the value when measured at a temperature range of 100 to 200°C at a heating rate of 10°C/min under the conditions of a sample length of 15 mm and an initial load of 2.0 ( ).α1 is -20×10-6/'
If it is less than C, the value of α■ (O~IO
Since it is too small compared to X 10 (i/℃"), it is difficult to set α□ to O~IOX 10-6 /℃ when combined with resin. On the other hand, α■ exceeds 20X 10-6 /℃ Similarly, it is too large compared to α1 of semiconductor components for mounting, so when combined with resin, α is 0 to IOX 1
It becomes difficult to set the temperature to 0-6/℃. Therefore, the present invention
-20
10-6 /℃≦αT≦20X 10-6 /℃
It was discovered that αT can be made to be approximately the same as (X 10-6 /°C). In the present invention, α■ is -10
, 3X 10-6 /℃ and meta-based wholly aromatic polyamide pulp whose α■ is 31.3X10-6, the α1 of each cancels each other out. It has been found that αT of the obtained paper-like material becomes a positive value or a negative value extremely close to O. On the other hand, αT is −
0, I
When used in combination with a meta-based wholly aromatic polyamide pulp having a temperature of 0.degree.

In other words, the aromatic polyetheramide short am has the ability to sufficiently suppress the expansion of meta-based wholly aromatic polyamide pulp, which is a binder component, in paper-like materials, and this is because α1 is polymethphenylene. It has a particularly large negative value compared to isophthalamide short fibers, and it is a rigid molecular chain in which the benzene ring and amide bond are connected at the para position.1
This is due to the inherent fiber properties of wholly aromatic polyetheramide short fibers, such as the inclusion of ether bonds in the molecular chain.

Thus, the paper-like material containing wholly aromatic polyether amide short fibers and meta-based wholly aromatic polyamide pulp is -20X
10-6 /℃≦αT≦20X α of 10-610C
, and when combined with a resin, it has the ability to sufficiently suppress the expansion of the resin and the resulting sheet has an α of the same level as that of the semiconductor component for mounting (0 to IOX 10-6/℃). It is possible to make it a thing. It is preferable that α■ of the paper-like material is a negative value, since the effect of offsetting with the resin becomes larger.

Furthermore, the paper-like material made of the wholly aromatic polyetheramide short fibers and the meta-based wholly aromatic polyamide pulp in the present invention has a heat shrinkage rate, a heat residual shrinkage rate, an equilibrium moisture content, and a humidity linear expansion coefficient that are higher than those of the conventional total. It is characterized by being significantly smaller than aromatic polyamide paper. The paper-like material is impregnated with or coated with a resin to form an electrically insulating layer and used as a base material or coverlay for a printed wiring board. At this time, various surface treatments may be applied to improve the adhesion between the paper-like material and the resin. The resin to be used is selected to have excellent electrical properties, chemical resistance, solvent resistance, water resistance, heat resistance, and adhesive properties. Preferred resins include polyfunctional epoxy compounds, imide compounds,
Polyfunctional isocyanate compounds, phenol/formalin condensates, resorcinol/formalin condensates, melamine/formalin condensates, xylene/formalin condensates, alkylbenzene/formalin condensates, unsaturated polyesters,
Polyfunctional allyl compound (diallyl phthalate).

Examples include triallyl(iso)cyanure-1 and the like), polyfunctional (meth)acrylic compounds (including epoxy acrylate and urethane acrylate), imide compounds, and amidimide compounds.

Preferred are polyfunctional epoxy compounds and imide compounds.

These are polyfunctional isocyanate compounds, phenol/formalin condensates, unsaturated polyesters, and diallylphthalate resins.

On the other hand, to improve adhesion and, if necessary, flexibility, use polyolefins (polyisobutylene, etc.), polyvinyls (polyvinyl chloride, polyacrylic esters, polyvinyl acetate, polyvinyl formal, polyvinyl acetal, polyvinyl butyral). It is desirable to mix or react with the resin, a rubber type (polyisobutylene, polybutadiene, chlorosulfonated polyethylene, polyepichlorohydrin, polychloroprene, etc.), a silicone type, a fluorine type, etc., or a copolymer thereof.

On the other hand, the resin forming the sheet of the present invention is not limited to thermosetting resins, but may also be thermoplastic resins such as Teflon, polyether, etherketone, polyphenylene sulfide, polycarbonate, and polyethersulfone.

Since these resins are impregnated or coated on paper-like materials to form a part of the base material or coverlay, they are especially those whose temperature linear expansion coefficient (α■) is not very large, preferably αT≦
200 x 10-6/℃, more preferably αT≦
A resin having a temperature of 100 x 10-6/°C is preferred.

A conventional impregnation method is used to apply the resin to paper-like materials.

Although a coating method can be used, for example, a film of the above resin is coated on a paper-like material alone or on a paper-like material and a conductor (
For example, a base material, a coverlay, or a printed circuit board can be manufactured by sandwiching the material between the materials (for example, copper foil) and performing hot-pressure molding. Alternatively, a base material, a coverlay, or a printed circuit board can be manufactured by scattering powder of the above-mentioned resin onto a single paper-like material or between a paper-like material and a conductor, and performing hot-pressure molding. By laminating a paper-like material and a film or powder, a laminated base material or printed circuit board with a high basis weight can be obtained.

In addition, lubricants, adhesion promoters, flame retardants, stabilizers (antioxidants) may be added to the resin within a range that does not impair the performance of the present invention.

UV absorbers, polymerization inhibitors, etc.), mold release agents, plating activators, and inorganic or organic fillers (talc, etc.).

Titanium oxide, fluorine polymer fine particles, pigments, dyes.

Calcium carbide, etc.) may be added.

After curing, the obtained sheet can be attached to a conductor layer or a printed wiring board on which a circuit has already been formed using an adhesive. It can also be laminated with the formed pudding/wiring board and cured by heating and pressurizing.

After curing, a conductive layer can be formed on the sheets 1 to 1 by physical vapor deposition or chemical vapor deposition, or a printed wiring board can be obtained by partially laminating the metal resist and forming a conductive layer by chemical plating. . Furthermore, the paper-like material may be laminated on the conductive layer thus formed via a resin to form a coverlay printed wiring board.

That is, in the present invention, a sheet made of a paper-like material and a resin may be used only as a base material of a printed wiring board, or may be used as a coverlay, or may be used as a base material and a coverlay.

<Effects of the Invention> The printed wiring board of the present invention has a low equilibrium moisture content of the paper-like material itself, and its heat shrinkage rate, heat residual shrinkage rate, and temperature linear expansion coefficient are extremely small. The solder heat resistance of the board for use is excellent. Furthermore, the temperature linear expansion coefficient of resin-impregnated paper can be made comparable to that of semiconductor components for mounting, so when used as a printed wiring board, it is possible to prevent solder bonding from the heat cycle that occurs when surface mounting semiconductor components. There will be no cracks in the parts.

Furthermore, since it has high heat-resistant dimensional stability, high-density circuits will not undergo dimensional changes due to expansion and contraction, resulting in circuit defects. Furthermore, since the humidity coefficient of linear expansion is small, there is little curling at high humidity, and the humidity-resistant dimensional stability is high, so even in a high-humidity atmosphere, a high-density circuit will not undergo dimensional changes and circuit defects.

<Example> The present invention will be explained in more detail with reference to Examples below.

The measurement method used in the examples is as follows.

Fiber measurement method in Table 1 (1) Tensile strength A universal tensile tester with a sample grip interval of 25 cm.

Instron 4 at a tensile speed of 10 Cm/min.
It was measured using C.

(2) Initial elastic modulus Strength measurement based on JISL-1017
It was calculated according to the following formula from the strength difference between 1 and 2% elongation in the elongation curve.

Modulus (g/de) − (strength difference between 1 and 2% (g/de)) xloo(3
) Density was determined by floating a sample in a mixture of carbon tetrachloride and n-hebutane.

(4) Crystallinity, orientation, crystal size determined from X-ray scattering intensity. The device is RU-3 manufactured by Rigaku Denki.
11 was used.

(5) Ripple fibers with an equilibrium moisture content of 5 g were washed in cyclohexane at 50° C. for 20 minutes to remove attached oil and the like. Next, JISL-10
After pre-drying for 1 hour at 50°C in accordance with 13, it was left in a desiccator at 20°C and 65% RH adjusted with sulfuric acid for 72 hours, and then its weight was measured. Next, the weight after drying at 105° C. for 2 hours was measured to calculate the equilibrium moisture content (%).

(6) Heating shrinkage rate A thermomechanical analyzer (THA: manufactured by Rigaku Denki ■) was used.

At 25°C, 140% RH, both ends of a filament bundle with a sample length of 15 mm were fixed to the device with instant adhesive, and a load of 2 was applied.
．． The temperature was increased to 350°C at a heating rate of 10'C/min, and the temperature was increased to 350°C relative to the sample length (ismm) before heating.
The shrinkage rate was calculated from the ratio of sample lengths.

(7) In the measurement method for heating residual shrinkage rate (6), after reaching 350°C, immediately lower the temperature to 25°C at a cooling rate of 10°C/min, measure the sample length after cooling, and measure the sample length before heating ( 15ml)
The residual shrinkage rate was calculated.

(8) In the measurement method of temperature linear expansion coefficient (6), the temperature is raised to 200'C and immediately 5
Temperature decreased at 10°C/min to 5°C, then immediately increased to 200°C
The temperature was raised at 0°C/min. 100-2 during this second temperature rise
The sample length before and after heating up was measured at 00°C, and the coefficient of linear expansion in the fiber axis direction was calculated.

Measurement method for paper-like materials in Table 2 (1) Thickness Measured using a peacock type thickness gauge in accordance with JIS P-8118.

(2) Equilibrium moisture content Same as the equilibrium moisture content of fibers in Table 1 JIS L-1013
Equilibrium moisture content (%) at 20°C, 165%RH
) was calculated. However, in this case, the sample was not washed with cyclohexane.

(3) Humidity linear expansion coefficient A square sample measuring 20 cm in length and 20 cm in width was pre-dried at 130° C. for 2 hours. then 20°C
The humidity was controlled for one week in a desiccator at 210% RH.

One week later, the lengths of both vertical and horizontal ends of the sample were read using a reading microscope.

Next, the sample was placed in a desiccator at 20° C. and 100% RH, and the humidity was controlled for one week. After the humidity conditioning is completed, read the length of both the vertical and horizontal ends of the sample using a reading microscope.
The humidity linear expansion coefficient at a 90% RH difference was calculated.

(4) Heating shrinkage rate 25°C, 40%RH, sample length 15mm, sample width 4.5mm paper-like material, load 2.0g, heating rate 10°C/min, same as the fiber measurement method in Table 1. Calculated using the method.

(5) Heating residual shrinkage rate Calculated using the same method as the fiber measurement method in Table 1 under the conditions of (4).

(6) Temperature Linear Expansion Coefficient (4) The fibers were determined in the same manner as the method for measuring fibers in Table 1.

The average value of the 8 candies (vertical and horizontal) in (3), (4), (5), and (6) above was calculated.

Measurement methods for copper clad plates in Table 3 (1) Thickness It was measured in the same manner as for the paper-like material in Table 2.

(2) Curl degree at high humidity: Vertical IOCM, horizontal IOCM copper clad plate sample at 20°
It was kept in a C290%RH desiccator for 3 days, and the degree of curl was expressed as the average distance between the two sides that curled closest to each other.

(3) Solder heat resistance, JIS C4481 (Test method for copper-clad laminates for printed circuits)
Compliant with. The sample was a square with a length of 5 cm and a width of 5 cm. Solder bath temperature is 260℃, 280℃.

One hour at 300°C was 60 seconds. After 60 seconds at each temperature, the nails were removed, and after cooling to room temperature, the copper foil surface and sheet surface were examined for blistering and peeling. On the other hand, the curl degree of the sample on the solder bath after 60 seconds at 300° C. and the sample taken out from the solder bath and cooled to room temperature was measured in the same manner as in (2).

(4) Temperature Linear Expansion Coefficient The average value of the horizontal values of rimples obtained by etching a portion of a copper clad plate with ferric chloride to remove copper using the same method as that for measuring paper-like materials in Table 2. was calculated.

Example 1. Comparative Examples 1 to 3 The following wholly aromatic polyamide short fibers (Table 1)
It was used.

Fully aromatic polyether amide fiber Technora ■Single yarn fineness 1.5de fiber length 5...
(Manufactured by Teijin ■) Polymetaphenylene isophthalamide fiber Conex ■ Single yarn fineness 1.5de Fiber length 5 mm (Manufactured by Teijin ■) Meta-based wholly aromatic polyamide pulp was produced by the following method.

Dissolve Conex ■ in N-medylpyrrolidone to 12%
A solution was created. On the other hand, a 30% aqueous solution of N-methylpyrrolidone was prepared and used as a nonsolvent.

The rotation speed shown in JP-A-52-15621@publication is 10.
00ORPM and a stirring device with a rotor diameter of 150 mm, the above polymer solution was supplied in a ratio of 1 part and undissolved @ 30 parts while stirring to obtain a meta-based wholly aromatic polyamide pulp.

Next, wholly aromatic polyether amide staple fibers and meta-based wholly aromatic polyamide pulp were mixed at a weight ratio of 50,150 to create a slurry, and the paper was made using a Tarapi square paper machine, followed by a rotary dryer at a surface temperature of 130°C. Contact dry.

After that, the metal roll surface temperature was 290℃, and the linear pressure was 200kg/
A paper-like product having a basis weight of 64 p/m was obtained by heat-pressure treatment with a metal-metal calendar at a speed of 5 m/min (Example 1, Comparative Example 1).

NOmeX paper (NOmeX 410.3 nil manufactured by DuPont), KaptOn film (KaptOn 100
As shown in Table 2 together with the evaluation results (Comparative Examples 2 and 3) for H, 1mil manufactured by DuPont, paper-like materials made of wholly aromatic polyetheramide short fibers and meta-based wholly aromatic polyamide pulp have equilibrium moisture content. The thermal expansion coefficient, humidity linear expansion coefficient, heating shrinkage rate, and heating residual shrinkage rate are extremely small, and the temperature linear expansion coefficient is also O.
It was a small value close to .

Examples 2 to 3 Copper cladding was performed using a paper-like material made of wholly aromatic polyether amide staple fibers listed as 1q in Table 2 and meta-based wholly aromatic polyamide pulp.

Epicoat 1001 (epoxy equivalent: 450~
500, made of oil-based silicone epoxy), Epicoat 154
(Epoxy N176-181. Manufactured by Yuka Shell Epoxy II), 4,4'-cyamino diphenyl sulfone (Roussel Uclaf)
Made by IIN).

After immersing in two types of 40% methyl ethyl ketone solutions consisting of a curing agent mainly consisting of a boron trifluoride complex compound (manufactured by Yuka Shell Epoxy ■), excess resin was removed using a mangle. Next, hot air drying was performed at 90°C for 1 minute and at 120°C for 3 minutes. Next, electrolytic copper foil (@35μm, fabric weight 30
0(]/TIt, made by Nippon Denki ■) was laminated at 130℃,
Press hardening was performed at 80 kg/cm for 2.5 minutes. Further, hot air curing was performed at 150° C. for 2 hours.

In addition, when films of two types of impregnated resin were made and the temperature linear expansion coefficient of the resin itself was measured, it was found that α□-70.4X10-
6/°C (Example 2), αT = 58.3X 10
-6X°C (Example 3).

Both Example 2 and Example 3 have excellent solder heat resistance, do not curl under high humidity, have a temperature linear expansion coefficient extremely close to O, and have high heat resistant dimensional stability. .

Comparative Examples 4 to 6 Paper-like material made of polymetaphenylene isophthalamide staple fibers and meta-based wholly aromatic polyamide pulp (Comparative Example 4)
), NOmeX paper (NOmeX 4103ml 1l
) (Comparative Example 5), Kapton film (Kapton ■ 1
(IOILlmil) Example 2 using (Comparative Example 6)
Copper cladding was carried out using the same method. Table 3 shows the evaluation results of the obtained copper clad board. Both are solder heat resistant.

Curling at high humidity and temperature linear expansion coefficient were poor.

Claims (1)

[Claims] Contains wholly aromatic polyetheramide short fibers and meta-based wholly aromatic polyamide pulp, and has a temperature linear expansion coefficient (α_T) of -20×10^-^6/℃≦α_T≦20×10^-^
A printed wiring board characterized in that a sheet made of a paper-like material and a resin having a temperature of 6/°C is used as a base material or a coverlay.