JPH02220492A - Printed circuit board - Google Patents

Abstract

PURPOSE:To enhance a heat-resistance and a mechanical property by a method wherein an insulating board is formed of a composite of a specific resin composition component and a glass fiber component. CONSTITUTION:An insulating board is formed of an armoatic polyether copolymer whose content ratio I:II of a repetition unit expressed by Formula I and a repetition unit expressed by Formula II is 15 to 35:65 to 85 (molecular ratio). Alternatively, it is formed of a composite composed of the following: 15 to 85wt.% of a resin composition component composed of 10 to 99wt.% of a copolymer and 1 to 99wt.% of a thermoplastic resin; 85 to 15wt.% of a glass fiber component. Thereby, it is possible to increase a thermal deformation temperature and to sufficiently hold a mechanical strength even at a high temperature; even when an electronic device is bonded by using a solder, it is possible to prevent the insulating board from being deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to printed circuit boards, and more particularly,
This invention relates to printed circuit boards with excellent heat resistance and mechanical properties used in electronic and electrical equipment.

[Conventional technology] Conventional printed circuit boards are made by coating a metal layer such as copper foil on the surface of a composite sheet made of a flat base material such as paper or glass fiber impregnated with thermosetting resin such as epoxy resin or phenol resin. It was formed by providing

However, when such a composite sheet of thermosetting resin is used as a printed circuit board, the working environment may be deteriorated due to the use of solvents etc. when handling the resin, and the Since it takes a long time to cure the plastic resin, it is industrially difficult to work with and is not preferred.

Therefore, in order to solve the above problems of thermosetting resin,
Printed circuit boards using thermoplastic resins such as crosslinked polyethylene and polyphenylene sulfide (hereinafter simply abbreviated as PPS) as resin components have been proposed.

[Problem N that the invention seeks to solve] However, the heat distortion temperatures of these crosslinked polyethylene resins and PPS resins are 135°C and 260°C, respectively, which are below the melting temperature of solder at 260°C, so it is difficult to print electronic devices. It was not easy to bond it to a circuit board by soldering.Also, it was not easy to bond it to a circuit board by soldering.Also, copper foil etc. This is because printed circuit boards with metal layers are difficult to work with in high-temperature environments, such as when soldering.

Its use has been severely limited.

[Means for solving the above-mentioned problems] In order to solve the above-mentioned problems, the present inventors have conducted intensive research, f.
As a result, a substrate formed by combining a specific aromatic polyether copolymer or a resin composition containing this copolymer with glass fibers in a specific ratio is
The present invention was completed based on the discovery that a printed circuit board with excellent heat resistance and mechanical properties can be obtained.

That is, one aspect of the present invention is a printed circuit board formed by forming a conductive layer on the surface of an insulating substrate, in which the insulating substrate has a repeating unit represented by the formula (A) and a repeating unit represented by the formula and the content ratio ([I] : [11) of the repeating unit represented by the formula [I] and the repeating unit represented by the formula [■] is 15 to
35: Resin composition component 1 consisting of an aromatic polyether copolymer having a molar ratio of 65 to 85 or 10 to 99% by weight of the copolymer and 1 to 90% by weight of a thermoplastic resin.
The printed circuit board is a composite of 5 to 5% by weight of B and 85 to 15% by weight of (B) a glass fiber component.

It basically consists of a genus layer.

(Aromatic polyether copolymer composition) The aromatic polyether copolymer may include a repeating unit represented by the formula obtained by reacting dihalogenobenzonitrile with 4.4°-dihydroxybiphenyl, and Halogenobenzophenone and 4,4-
The present invention will be specifically described in detail below.

(1) Insulating substrate The printed circuit board of the present invention comprises an insulating substrate formed of a composite of an aromatic polyether copolymer or a resin composition component containing this copolymer and a glass fiber component, and this insulating substrate. It is an aromatic polyether copolymer with a structure having a repeating unit represented by gold provided on the surface of.

In this invention, the formula [
II and the content ratio of repeating units of formula [11] ([I
I: [■]) is 15-35: 65-85 (molar ratio)
It is important that the molar ratio is preferably within the range of 20-30:70-80 (molar ratio).

The aromatic polyether copolymer has a high glass transition temperature and excellent heat resistance.Also, despite the high glass transition temperature, it has a low crystal melting point and is easy to be molded. It has excellent physical properties, corrosion resistance, etc.

Specifically, the aromatic polyether copolymer in the present invention usually has a glass transition temperature of 165 to 190°C and a low crystal melting point of 340 to 385°C.

In the aromatic polyether copolymer, the [I
When the content of the repeating unit represented by formula I is less than 15 mol %, the glass transition point decreases and heat resistance and moldability deteriorate. On the other hand, if it exceeds 35 mol %, crystallinity is lost and heat resistance and solvent resistance decrease.

The aromatic polyether copolymer may be a random copolymer, a block copolymer, an alternating copolymer, or a mixture thereof; however, depending on the manufacturing method, etc. Considering this, a random copolymer is preferable.

(Production of aromatic polyether copolymer) The aromatic polyether copolymer may contain, for example, 4,4'-dihalobenzophenone, dihalogenobenzonitrile, 4,4'
-dihydroxybiphenyl in the presence of an alkali metal compound in a neutral polar solvent.

-4.4'-dihalobenzophenone - the above 4.4'
-Dihalobenzophenone, for example 4.4'-difluorobenzophenone.

Examples include 4.4'-dichlorobenzophenone and 4-chloro-4'-fluorobenzophenone. In addition, 4
．． In 4'-dihalobenzophenone, the benzene nucleus may be substituted with a different type of halogen atom.

Among these, 4,4'-difluorobenzophenone and 4,4'-dichlorobenzophenone are preferred.

Incidentally, these 4,4'-dihalobenzophenones may be used alone or alternatively.

Two or more types may be used in combination.

m-Dihalogenobenzonitrile - The dihalogenobenzonitrile is, for example, 2
．． 4-difluorobenzonitrile, 2゜6-difluorobenzonitrile, 2,4-dichlorobenzonitrile, 2
．． Examples thereof include 6-dichlorobenzonitrile, 2,4-dibromobenzonitrile, and 2°6-dibromobenzonitrile.

In addition, in the dihalogenobenzonitrile, a different type of halogen atom may be substituted for the benzene nucleus.

Among these, 2,4-dichlorobenzotolyl, 2
．． 6-dichlorobenzonitrile is preferred. These dihalogenobenzonitrile may be used alone or in combination of two or more.

-4,4°-dihydroxybiphenyl-4,4
°-Dihydroxybiphenyl can be used as it is as a salt, but if desired, it can be converted into an alkali metal salt in advance.

It can also be used as an alkali metal salt of 4.4°-dihydroxybiphenyl and serve as both a monomer component and an alkali metal compound component. Note that among the alkali metal salts, sodium salts and potassium salts are preferred.

These various alkali metal salts can be used alone, two or more can be used together as a mixture, or a mixture with 4.4゜dihydroxybiphenyl (dihydroxy form) in any proportion. It can also be used as.

1 Quantity Ratio - 1 the above 4.4'-dihalobenzophenone and the above 4.4°
The ratio of the dihydroxybiphenyl and the dihalogenobenzonitrile used is 65 to 85 mol%, preferably 70 to 80 mol% of the 4,4'-dihalobenzophenone.
The dihalogenobenzonitrile is in the range of 35 to 15 mol%, preferably 30 to 20 mol%, and the 4.4'-dihydroxybiphenyl is in the range of 4.4'-
It is used in the same number of moles as the total amount of dihalobenzophenone and dihalogenobenzonitrile.

- Alkali metal compound - As the alkali metal compound, those capable of converting the 4°4°-dihydroxybiphenyl into an alkali metal salt can be used, but usually an alkali metal carbonate and/or Using alkali metal bicarbonates.

However, when the alkali metal salt of 4,4°-dihydroxybiphenyl is used as a monomer or comonomer, these can also be used in combination with the alkali metal compound.

Examples of the alkali metal carbon salt include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate. Among these, sodium carbonate and potassium carbonate are preferred.

Examples of the alkali metal bicarbonate include lithium carbon hydrogen, sodium hydrogen carbonate, potassium hydrogen carbonate,
Examples include rubidium hydrogen carbonate and cesium hydrogen carbonate.

Among these, sodium hydrogen carbonate and potassium hydrogen carbonate are preferred.

The alkali metal carbonates and alkali metal bicarbonates are usually used in the form of anhydrous substances, but if desired, they can also be used in the form of water-containing substances such as hydrates and thick aqueous solutions.

It is desirable that the water added to the reaction system and the water produced by the reaction be appropriately removed from the reaction system during or prior to the reaction (condensation reaction).

The alkali metal salts may be used alone or
Any two or more types may be used together in any ratio as a mixture.

The amount of the alkali metal salt used is usually 1.00 per 1/2 mole of the 4.4°-dihydroxybiphenyl.
~3.0θ gram equivalent, preferably 1.
It is within the range of 0.05 to 2.00 gram equivalents.

(11) Neutral Polar Solvent (11) As the neutral polar solvent, known ones can be used. Specifically, for example, dimethylformamide, diethylformamide, dimethylacetamide, diethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, diethylsulfoxide, sulfolane, dimethylimidazolidinone, diethylimidazolidinone,
Examples include biphenyl sulfone.

Among these, N-methylpyrrolidone and sulfolane are preferred, and N-methylpyrrolidone is particularly preferred.

In addition, these neutral polar solvents may be used alone, or two or more may be used in combination as a mixed solvent, etc.
Furthermore, it can also be used as a mixed solvent with other inert solvents, especially aromatic solvents such as benzene, toluene, and xylene that can azeotropically remove water from the reaction system.

-1 Reaction Conditions 11 The dihalogenobenzonitrile, the 4°4°-dihalobenzophenone, and the 4.4' dihydroxybiphenyl described in a above are mixed in the neutral polar solvent in the presence of the alkali metal compound. When producing the aromatic polyether copolymer by reacting (condensation reaction) in
The temperature is in the range of 50 to 380°C, preferably 180 to 33°C.
It is in the range of 0°C.

Moreover, the monomer concentration is suitably 0.1 to 4 mol/crossing (total monomer amount (mol)/solvent amount (text)).

The reaction time cannot be specified uniformly because it varies depending on the type of sulfuric acid or alkali metal compound used, the proportion used, the reaction temperature, etc., but it is usually in the range of 0.1 to 10 hours, preferably 1 hour. ~3 hours.

There is no particular restriction on the reaction pressure, and the reaction may be carried out under reduced pressure, normal pressure, or increased pressure, but it is usually preferable to carry out the reaction near normal pressure.

The reaction atmosphere is usually preferably under an inert atmosphere such as under an inert gas flow of nitrogen, argon, helium, etc. or under reduced pressure exhaust.

In addition, the aromatic polyether copolymer thus obtained preferably has a melt viscosity of 3.000 voids or more at 400°C6, and if it is less than this, the heat resistance and mechanical strength are insufficient. .

(Glass fiber component) As the other glass fiber component constituting the insulating substrate, fibers of various types of glass such as quartz glass and soda glass can be used. There are no limitations, and for example, it may be manufactured by a direct melting method or by a marble method.

Specifically, glass fiber is basically formed by stretching glass from a molten state, but mainly long fibers are formed continuously from a platinum nozzle, molten glass is ejected from pores using centrifugal force, There are short fibers called glass wool, which are made into mat-like fiber aggregates by blowing combustion gas or water vapor, and the long fibers include E glass (SiOz4jL 20z・CaO・N
Typical examples include alkali-resistant glass containing ZrO2 and acid-resistant glass C glass (SiOz・A fL203 ・CaO・MgO・Zn).
O, B 203 , Na 20-K 20 series), etc.

In addition, if these glass fibers are subjected to surface treatment in advance, functional groups may be introduced onto the surface of the glass fibers, and these functional groups improve the wettability with the aromatic polyether copolymer that is the matrix. As a result, it is possible to improve the mechanical strength, etc. of the resulting insulating substrate.

Such surface treatments include, for example, chemical oxidation methods, electrolytic oxidation methods, gas phase oxidation methods, and coating methods using organic and/or inorganic compounds. , these can be combined for surface treatment. A preferred surface treatment includes, for example, a treatment method using a silane coupling agent.

Furthermore, the short fibers include 5iO2-AfL203・Na
Examples include 20-CaO/MgO/B2O3 glass.

These glass fibers generally have a diameter of 5 to 20 mm, preferably 7 to 15 mm, and a length of about 0.1 to 30 mm.

This glass fiber is used in the form of a woven fabric, a non-woven fabric, or a short fiber.

(Additive components) When forming an insulating substrate, antioxidants, thermal stabilizers, A crystal nucleating agent, etc. can be added.

The antioxidants include phenolics such as 2,6-di-tert-butyl-para-cresol, phenyl-β
- Amine type such as naphthylamine, sulfur type such as lauryl stearyl thiodipropionate, phosphorus type such as tridecyl phosphite, hydrazine type such as N-salicyloyl N°-aldehyde hydrazine, amide such as N,N'-biphenyl oxide system etc. can be used.

As the heat stabilizer, a lead salt stabilizer, a metal soap, a metal salt liquid stabilizer, an organic tin stabilizer, an antimony stabilizer, a nonmetallic stabilizer, etc. can be used.

As the crystalline nucleating agent, titanium oxide, talc, etc. can be used.

The insulating substrate of (a) is made by mixing the aromatic polyether copolymer component and the short fiber glass fiber component and compression molding the mixture to form (a) the long fiber glass fiber into a mat shape. By scattering pellets or powdered aromatic polyether copolymer component onto the formed glass fiber component or into a woven proboscis shape, and then heating and compression molding the aromatic polyether copolymer component, or (c) aromatic polyether copolymer component. After forming a polymer component into a sheet and laminating this sheet onto a glass fiber component formed into a long fiber mat or woven fabric,
By heating and compression molding, the glass fiber and the aromatic polyether copolymer can be integrally formed.

Since the insulating substrate composited in this manner can maintain its shape by the glass fibers even at high temperatures, its mechanical properties such as bending strength and tensile strength are improved, and its thermal deformation temperature is significantly increased.

(2) Conductive layer A conductive layer provided on the surface of the insulating substrate.

It can be formed from an electrolytic metal foil of a metal selected from copper, aluminum, nickel, and silver, or a metal foil obtained by rolling.

Such a conductive layer usually has a thickness of 5 to 500 gm, preferably 10 to 100 gm, especially 15 to 50 gm in the case of rolled copper foil.
In the case of electrolytic copper foil, the thickness is about 10 to 50 μm.

In order to form the conductive layer of the metal foil on the insulating substrate, the temperature is generally 50 to 200°C after applying an adhesive to the surface of the insulating substrate or sandwiching the adhesive layer film.

Preferably at a temperature of Zoo-150°C, generally 0,1
~l Okg/cm2. Preferably 1-5 kg/cm
Compress and mold using pressure 2.

Further, the conductive layer can be formed on the surface of the insulating substrate by a non-electrolytic deposition method, a vapor deposition method, a vaporization method, a sputtering method, or the like.

Note that the conductive layer can be formed not only on one side but also on both sides of the insulating substrate.

(3) Printed circuit board The printed circuit board thus obtained is then subjected to a conductor pattern formed by a subtractive method (photoetching method) or an additive method, and then through holes are formed by a drill to form an electronic device. By welding with solder, electronic computers, electronic exchangers, O
A equipment, wire communication equipment, wireless communication equipment, electronic application equipment,
Industrial electronic equipment such as electrical measuring instruments, televisions, radios,
It can be used as a printed circuit board for consumer electronic equipment such as tape recorders, audio equipment, video tape recorders, etc.

[Examples] In order to more specifically explain the printed circuit board of the present invention, Examples are given below, but the present invention is not limited thereto.

(Example 1) l) Production of aromatic polyether copolymer In a reaction chamber with an inner volume of 5×, equipped with a stirring device, a Dean-Starck trap filled with toluene, and an argon blowing tube, 2.6
-cyclobenzonitrile 32.34g (0,188
mole), 4.4'-dihydroxybiphenyl 139.6
G, (0.75 mol), * potassium acid 124.39 g
(0,9 mol) and N-methylpyrrolidone! ,! l
was added, and the temperature was raised from room temperature to 195°C over 1 hour while blowing argon gas. After the temperature was raised, a small amount of toluene was added and the produced water was removed by azeotropy.

Then, the reaction was carried out at a temperature of 195°C for 30 minutes.
Then 4,4'-difluorobenzophenone 122.8
A solution of 5 g (3 moles at 0,511°C) dissolved in 1.5 J1 of N-methylpyrrolidone was added and the reaction was further carried out for 1 hour. 6 After the reaction was completed, the product was pulverized with a blender (manufactured by Warning). Thoroughly wash with wood and dry to obtain aromatic polyether copolymer 2 in the form of white powder.
58 g (yield lOO%) was obtained.

When measuring the thermal properties of this aromatic polyether copolymer, the glass transition temperature (Tg) was 182°C, the melting point was 379°C, and the thermal decomposition onset temperature (Td) was 562°C (5% weight loss in air). )was there.

2) Production of printed circuit board The pellets of the aromatic polyether copolymer described above are extruded and the content of the aromatic polyether copolymer in the insulating board is set to the value shown in Table 1. wall thickness 0.5
Two sheets (50 mm x 50 mm) were manufactured.

Next, a continuous glass fiber mat (manufactured by Asahi Fiberglass Co., Ltd.: GSM, M2SO4) 3 with one sheet in between
A laminate having a layered structure was obtained.

Then, this entire layer was heated to 400°C for 50m.
m x 50m m c7) Supply to flat plate mold, 6k
It was heated and compressed for 5 minutes at a pressure of g/cm2. then 250
The mixture was transferred to a cooling press set at .degree. C. and cooled for 5 minutes under a pressure of 30 kg/cm2 to obtain an insulating substrate made of a composite sheet with a thickness of 1.1 mm.

An insulating substrate made of this composite sheet is used as an insulating substrate, and after bonding an electrolytic copper foil to this insulating substrate with an epoxy resin adhesive, heat and pressure treatment is performed at a temperature of 120°C and a pressure of 5 kg/c*2. A printed circuit board in which the copper foil and the insulating board were integrated was obtained.

Various physical properties of this printed circuit board were measured according to the following measurement method.

Heat distortion temperature (ASTM-0648) Bending strength (ASTM-0790) Peel strength of copper foil (JIS-CG481) Dielectric constant dielectric loss tangent (A!97M-0150) The results are shown in Table 1.

(Example 2) A printed circuit board was manufactured in the same manner as in Example 1 except that the resin content and glass fiber content were changed to those shown in Table 1.

The results are shown in Table 1.

(Example 3) A resin obtained by blending 20 parts by weight of polyether ether ketone with 80 parts by weight of the aromatic polyether copolymer prepared in (1) of Example 1 and melt-kneading the mixture. A printed circuit board was manufactured using the composition in the same manner as in Example 1 (2) above.

The results are shown in Table 1.

(Comparative Example 1) A printed circuit board was manufactured in the same manner as in Example 1, except that a thermoplastic resin, polyether ether ketone (hereinafter simply abbreviated as PEEK) manufactured by IC1, UK, was used as the resin component. The physical properties were measured in the same manner as in Example 1.

The results are shown in Table 1.

(Hereinafter, blank space) [Effects of the invention] The printed circuit board of the present invention thus obtained has the following:
Since the thermal deformation temperature is high and the insulating substrate can maintain sufficiently high mechanical strength even at high temperatures, the insulating substrate will not be deformed even when electronic devices are welded with solder.

Since the thermal deformation temperature of the printed circuit board of the present invention is about 335°C, it will not deform at a temperature of about 260°C, which is the melting temperature of solder, and various electronic devices can be easily welded. It is extremely useful.

Claims (1)

[Claims] (1) In a printed circuit board formed by forming a conductive layer on the surface of an insulating substrate, the insulating substrate has a repeating unit represented by the formula (A) ▲Mathematical formula, chemical formula, table, etc.▼[I] , formula▲There are mathematical formulas, chemical formulas, tables, etc.▼ [II] It has a repeating unit represented by the formula [I] and the repeating unit represented by the formula [II]. Content ratio ([I]:[II]) is 15 to 35
: 65-85 (molar ratio), or a resin composition component consisting of 10-99% by weight of the copolymer and 1-99% by weight of a thermoplastic resin 15-85
% by weight and (B) a glass fiber component of 85 to 15% by weight.