JPS61167544A - Printed substrate - 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] The present invention uses a ceramic, metal, or alloy plate as a substrate, which not only has good heat resistance but also good heat dissipation and dimensional stability due to heat. Regarding printed circuit boards. More specifically, (A) metal or alloy plate, (8) ceramic layer, (C) (1) ethylene-
A crosslinked layer of a mixture consisting of an acrylic acid copolymer and/or an ethylene-methacrylic acid copolymer and (2) a saponified product of an ethylene-acetic vinyl copolymer and (D) a conductive metal layer are laminated in sequence. The purpose is to provide a printed circuit board that uses a ceramic board as a substrate, which not only has good heat resistance but also good heat dissipation and excellent dimensional stability due to heat. It is.

With the development of the electronics industry, electronic components have become smaller and the use of ceramic printed circuit boards, which have both high density and high density, has become popular. Ceramic boards used as printed circuit boards not only have good electrical properties but also have thermal stability, and take advantage of their small dimensional change in the thickness direction to create through-hole printed circuit boards (multilayer boards) on both sides. It is used as. Conventionally, alumina and the like have been used as ceramic materials for ceramic plates.

The reason for this is that conventionally, laminating copper foil on ceramic plates has rarely been done.

This is because there is no adhesive that has good adhesion to either ceramic materials or copper. Some attempts have been made to use epoxy resin as an adhesive, but it has not been put to practical use because its stone contact properties are not necessarily satisfactory.
This is because even if an epoxy resin were used to bond the ceramic plate and the copper foil, the circuit would be likely to break due to the difference in thermal expansion coefficient between the two.

Based on these facts, in order to manufacture ceramic printed circuit boards, tungsten, molybdenum,
After alternately printing and drying a conductive paste mainly composed of powder of a metal with a high melting point such as manganese and an insulating paste mainly composed of powder of ceramics (for example, alumina), a weakly reducing paste is applied to prevent metal oxidation. A wet ceramic multilayer printed circuit board obtained by firing in an atmosphere of There is a dry ceramic multilayer printed circuit board that repeats the process. In order to miniaturize and increase density, wet ceramic multilayer wiring boards are sintered with a
Thermal shrinkage of ~20% occurs, causing problems such as wire breakage.

In addition, as a printed circuit board that takes advantage of its heat dissipation properties, there is a printed circuit board that uses ceramics on a metal plate as an insulating substrate by thermal spraying using plasma flame spraying, arc flame spraying, or the like.

However, ceramic substrates manufactured by such conventional methods have the following drawbacks.

The solvent in the conductor and insulation paste that is repeatedly printed on the ceramic substrate expands the green sheet and causes a dimensional change.In other words, when the conductor and insulation paste dries, the volatile solvent causes the green sheet to shrink in volume, and this process is repeated. This changes the dimensions of the substrate. In particular, there are drawbacks that vary depending on the type of circuit. In addition, when printing these conductors, the occurrence of scratches, wire breakage due to adhesion of dust, and pinholes increases, and when screen printing is used, there is a limit to the width of the circuit line, which prevents high density. Furthermore, the printed circuit has many irregularities, which currently reduces the reliability of the connection with the chip when mounting the circuit.

Instead of the conventional etching method for copper-clad laminates, we have developed an additive method that applies plastic plating technology to draw circuits directly onto the resin board using electroless plating, and a substratification method that uses a combination of this plating and etching method. Eve method started to be used. The reason why this additive method has become popular is that it is an effective method for simultaneously forming through-holes and pattern plating for high-volume, low-mix resin laminates. The performance has been improved and it is now possible to obtain highly fine lines. Recently, a resistless method has also been developed in which ultraviolet rays are directly applied to a photoreaction catalyst mixed in the adhesive layer through a photomask to precipitate metal nuclei and electroless plating is performed.

However, the conventional paper-phenolic resin, glass-epoxy resin, and polyimide resin substrates used in these additive methods do not have good adhesion to the plating film, resulting in blistering, peeling, and thickening. When thermal stress is applied due to the large coefficient of thermal expansion in the horizontal direction,
In particular, cracks often occur in the plated parts of fine patterns. Furthermore, when drilling holes in multilayer boards, smearing occurs, which prevents connection with plating and reduces connection reliability. Moreover, the surface of thermally sprayed ceramics is markedly uneven, and the ceramic insulating layer is porous, making it impossible to bond with metal layers such as plating.
metal base.

Ceramic sprayed substrates have only been formed with circuits using conductive adhesives, etc. Therefore, there is a need for the development of a method for forming circuits on ceramic sprayed substrates by direct plating, vacuum evaporation, etc.

From the above, the present invention does not have these drawbacks, takes advantage of the heat dissipation characteristics of conventional ceramic substrates, and improves the lack of strength, which is the drawback of ceramic substrates, by thermally spraying ceramics on a metal plate base. The purpose of this invention is to obtain a printed circuit board.

μ According to the present invention, the above problem is solved.

(A) Plate of aluminum, copper or iron or alloys of these metals; (B) Ceramic layer; (C) (1) ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer” [hereinafter ``copolymer (1)''] and (2) ``ethylene-vinyl acetate copolymer'' [hereinafter referred to as ``copolymer (2)''], and ) Conductive metal layers are sequentially laminated, the thickness of the metal or alloy plate is 0.1 to 5 mm, the thickness of the ceramic layer is 100 mm to 10 mm, and the crosslinked material is boiling. The layer contains at least 80% by weight of a residue having a diameter of 0.1 mm or more after extraction treatment with toluene for 3 hours, and the proportion of copolymer (1) in the mixture is 20 to 80% by weight. The thickness is from 0.2 microns to 1000 microns,
And the thickness of the conductive metal layer is 100 to 200 microns.

Furthermore, this layer can be formed by a printed circuit board formed by any one of metal vapor deposition, electroless plating, and a combination of electroless plating and electrolytic plating.

(A) Metal and alloy plate The metal and alloy plate used in the present invention plays a role such as heat radiation, and has a thickness of 0.1 to 51 mm.
In particular, those with 0.2 to 2.5 layers are preferable.The types of metals include aluminum, copper, iron, and alloys containing these metals as main components (for example, aluminum alloys, stainless steel, bronze).

CB) Ceramic layer The ceramic layer used in the present invention can be manufactured by firing to form a plate or by forming a thin film on the surface of a metal plate.

Methods for forming thin films include chemical vapor deposition (CVD), which uses chemical reactions, and film deposition methods, which use physical means, such as vacuum evaporation, sputtering, and thermal spraying. Among these methods, the vacuum evaporation method is
This is a method of depositing a substance under a high vacuum, usually 10'Torr or less, and is performed by resistance heating, high frequency heating, electron impact, laser heating, etc. Furthermore, a commonly used thermal spraying method can be used; a high heat source (for example, plasma) is used to melt the high-melting point ceramic, and at the same time the material is sprayed at high speed to coat the surface of the material. This is the way to do it.

For example, 1. When argon, helium, hydrogen, nitrogen, etc. are used as the gas for plasma generation, the flame can reach an extremely high temperature of approximately 1500°C. Other methods include flame spraying and arc spraying using oxygen-acetylene, in which particles fly at high speeds around the speed of sound and form a dense ceramic coating on the surface of the metal plate. With flame spraying it is possible to reach temperatures of about 2400°C, and with arc spraying it is possible to reach temperatures of about 5000°C. This plasma can be preferably used because 1) the plasma flame is a neutral flame, so the oxidation-reduction force is weak, and the thermal spray material (ceramic material) is less likely to change in quality due to oxidation or reduction. In this method, 1 (IKW low energy thermal spray gun to 200KW
It is possible to use a gun that matches the size and shape of the object up to the thermal spray gun.

In addition, the sintering method varies depending on the particle size, particle size distribution, agglomeration state, impurities, etc. of the starting material ceramics, as well as the sintering conditions such as the forming method, sintering temperature, time, and atmosphere. A sintered product is obtained. This sintering method also includes reaction sintering method, pressure sintering method, ()IP method, HIP method),
There are pressureless sintering methods, gas pressure sintering methods, etc. Furthermore, recently, injection molding methods have become popular for mass production.

In this method, ceramic powder and an organic binder are generally mixed in advance, the resulting mixture is used to make a primary molded product using an injection molding machine, and the product is made into a product through a degreasing process and a main sintering process.

The methods for forming and sintering the thin film are industrially practiced and widely known.

As for the type of ceramics, alumina (AM203)
, silicon nitride (Si3 N4), silica (Si0
2), titanium nitride (TiN), titanium carbide (Ti
e) Fermented zirconium (zirconia, ZrO2)
, AlI3 03-5i02 series (mullite porcelain)
ZrO2・5i02, beryllum oxide (Bed),
Magnesium oxide (magnesia, Mg0), BaTiO
3,5iTi03, boron nitride (BN), and boron carbide (84C). Among these ceramics, alumina and silicon nitride are preferable. In particular, alumina is relatively inexpensive and has good heat resistance and thermal conductivity. , not only has excellent mechanical strength, impact resistance, electrical insulation and chemical durability, but also is easy to process, so it can be preferably used.

The thickness of the ceramic substrate varies depending on the method of forming the thin film and the method of firing. In the method of forming a thin film,
In general, it is 100A to 0.1μ, particularly preferably 1 to 100μ, and in the firing method, it is usually 50μ to 1OI, and 0
．． 1mm to 1.5cm is desirable.

(C) Mixture (1) Ethylene-acrylic acid copolymer and ethylene-
Methacrylic acid copolymers and/or ethylene-acrylic acid copolymers used to produce the mixtures of the invention
Methacrylic acid copolymer is produced by combining ethylene and acrylic acid or ethylene and methacrylic acid at high pressure (generally 50 kg/
crn' or more, preferably 100 kg/crn'' or more) in the presence of a free radical generator (usually an organic peroxide).The physical properties of each of these are well known. This is what is being done.

The copolymerization ratio of acrylic acid or methacrylic acid in these copolymers is 1 to 50% by weight, respectively.

A copolymerization ratio of acrylic acid or methacrylic acid in these copolymers is preferably 5 to 50% by weight. If the copolymerization ratio of acrylic acid or methacrylic acid is less than 1% by weight, it is impossible to obtain a uniformly thin walled product. On the other hand, if it exceeds 50% by weight, softening may occur. point becomes too low, making handling and transportation inconvenient.

(2) Saponified product of ethylene-vinyl acetate copolymer,
The saponified product of ethylene-vinyl acetate copolymer used to produce the mixture of the present invention is obtained by saponifying (hydrolyzing) the ethylene-vinyl acetate copolymer. Hydrolysis is generally carried out using caustic soda in methyl alcohol.In producing the saponified product of the present invention, it is usually desirable to have a hydrolysis rate of 90% or more. The combination is obtained by copolymerizing ethylene and vinyl acetate in the same manner as the above-mentioned ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer. The copolymerization ratio of vinyl acetate in this ethylene-vinyl acetate copolymer is generally 1 to 80% by weight, particularly preferably 5 to 60% by weight, and the copolymerization ratio of vinyl acetate in this copolymer is 1% by weight. If the amount is less than 80%, it is not possible to obtain a uniformly thin walled product, while if it exceeds 80fi amount%,
The softening point decreases, making handling at room temperature difficult.

Saponified products of these ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, and ethylene-vinyl acetate copolymers are industrially produced and used in a wide variety of fields, and we will discuss their manufacturing methods. is also well known.

(3) Mixing ratio The mixing ratio of ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer in the mixture of the present invention is 20 to 80% by weight (i.e., ethylene-vinyl acetate copolymer The mixing ratio is preferably 80-20% by weight), 25-75% by weight, particularly 30-70%
% by weight is preferred. If the mixing ratio of the ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer in these mixtures is less than 20% by weight, the number of carboxyl groups (-COOH) is lower than the hydroxyl group (-
OH), hydroxyl groups that do not contribute to the condensation reaction remain, resulting in poor heat resistance. On the other hand, 80
If it exceeds % by weight, on the contrary, there are too many carboxyl groups contributing to the condensation reaction, so that unreacted groups remain and heat resistance and moisture resistance are not improved, which is not desirable.

(4) Mixing method To produce the mixture of the present invention, the saponified products of the above ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer and ethylene-vinyl acetate copolymer are uniformly mixed. This can be achieved by As a mixing method, tri-blending may be performed using a mixer such as a Henschel mixer, which is commonly used in the field of olefin polymers, or a mixer such as a Banbury mixer, Niegoo, roll mill, and screw extruder. It can be obtained by melt-kneading using. At this time, a homogeneous mixture can be produced by tri-blending in advance and melt-kneading the resulting mixture. In addition, the carboxylic acid group (-C:0OH) possessed by the ethylene-acrylic acid and/or ethylene-methacrylic acid copolymer used for melt crosstalk and the hydroxyl group (-C:0OH) possessed by the saponified product of the ethylene-vinyl acetate copolymer. -OH) does not undergo a crosslinking reaction (condensation reaction) in the wood structure, and it is necessary that fish eyes do not occur (slight crosslinking may be allowed). Therefore, the melting temperature is lower than that of these ethylene-acrylic acid compounds. This is the temperature at which the polymer and/or the saponified product of the ethylene-methacrylic acid copolymer and the ethylene-vinyl acetate copolymer melts, but at which no crosslinking reaction occurs. The melting temperature varies depending on whether or not a crosslinking accelerator is added in the latter stage, as well as their type and amount added, but in the case where a crosslinking accelerator is not added, it is usually 180°C or lower, especially 100°C or less.
50°C is preferable; below 100°C is not preferable because these resins are not completely melted; on the other hand, when a crosslinking accelerator is added (blended), the temperature is generally 140°C.
or less, and is carried out at a temperature of 100°C or higher.

In producing this mixture, stabilizers against oxygen, light (ultraviolet light) and heat, metal deterioration inhibitors, flame retardants, electrical property improvers and antistatic agents commonly used in the field of olefinic polymers are used. , additives such as lubricants, processability improvers, and adhesion improvers may be added to the extent that they do not impair the characteristics (physical properties) of the thin-walled product of the present invention.
Furthermore, by adding a crosslinking accelerator such as an epoxy compound, P-)luenesulfonic acid and AM-impropoxide, ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer and ethylene - The crosslinking described below with the saponified vinyl acetate copolymer can be further completed. The amount added is usually at most 0.1 part by weight (preferably 0.01 to 0.05 part by weight) per 100 parts by weight of these resins. Furthermore, alumina.

It is also possible to improve the insulation by adding an insulating ceramic such as silicon nitride.

Furthermore, the function of the present invention can be further improved by filling with inorganic powder, glass fiber, glass beads, etc.

The mixture obtained as described above is produced into a thin-walled product as described below. When using a thin material in the form of a film or sheet, an extruder, which is widely used in the production of T-gui film, which is commonly used in the field of thermoplastic resins, and film by the inflatable wrapping method, is used. The temperature is below 250°C. Karini, 2
When extruded at temperatures exceeding 50°C, some of the saponified products of the ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer and ethylene-vinyl acetate copolymer crosslink, forming small gel-like particles. A uniform extrusion molded product cannot be obtained due to the occurrence of crosslinking.For these reasons, the extrusion temperature should be kept in the same temperature range as in the case of melt mixing described above, regardless of whether a crosslinking accelerator is added (compounded) or not. be.

In any of the above cases, after manufacturing the thin-walled objects, the thin-walled objects with good transparency are made by rapidly cooling them in a water-cooling roll or a water bath to prevent adhesion between the thin-walled objects or between the thin-walled objects and a take-up roll. can get. The thickness of the thin wall thus obtained is between 0.2 and 1000 microns, preferably between 0.2 and 500 microns, particularly preferably between 0.2 and 200 microns.

It is important that neither the mixtures described above nor the thin-walled products described above are crosslinked. In other words, "3 with boiling toluene"
After the extraction process, the amount of "residue with a diameter of 0.1 micron or more" (hereinafter referred to as "extraction residue") is generally at most 15% by weight, preferably 10% by weight or less, particularly 5% by weight or less.
It is preferably less than % by weight. If the extraction residue of mixtures and thin-walled products exceeds 15% by weight, the moldability will decrease when producing mixtures and thin-walled products, resulting in a uniform thin-walled product (molded product).
is not obtained.

In manufacturing the printed circuit board of the present invention, the above-mentioned metal or alloy plate, ceramic layer, and thin material are placed in this order, and the copolymer (1 ) and the saponified copolymer (2) crosslink, resulting in a laminate with good adhesiveness.

(Spring heating/pressure treatment The thin-walled product obtained as described above exhibits the same behavior as a normal thin-walled product because crosslinking has hardly progressed. In order to impart heat resistance to the thin-walled product, It is important to heat and pressurize within the range of 400℃.
20-30 minutes in the range of 00-180℃, 180-24
By heating and pressurizing for 10 to 20 minutes at 0°C and 0.1 to 10 minutes at 240 to 400°C, a crosslinking reaction (condensation reaction) occurs within the resin, improving adhesiveness and heat resistance. Significantly improved. The pressurization conditions are generally 5Kg/Cm' (gauge pressure) or more, and 10 to 200
Kg/crn' is desirable, especially 10-10
0 Kg/crn' is preferred. Furthermore, in order to obtain uniform adhesion, a method of applying pressure with a slight load under vacuum and reduced pressure is also used.

Since the thin-walled article obtained by the present invention exhibits thermocompression adhesion (adhesiveness) at a temperature of 100° C. or higher, the effects of the present invention can be further enhanced by bonding it to metal at the same time as the crosslinking treatment. That is, a mixture of an ethylene-acrylic acid copolymer and/or an ethylene-methacrylic acid copolymer and a saponified product of an ethylene-vinyl acetate copolymer exhibits thermoplasticity at a temperature of 250°C or lower; By heating and pressurizing the material to a temperature above .degree. C., it undergoes a crosslinking reaction and exhibits adhesive properties at the same time.

To produce a laminate in this way, a thin section of the uncrosslinked mixture is placed on the side of a two-layer ceramic layer consisting of a metal or alloy plate and a ceramic layer.

It is sufficient to heat and pressurize to the temperature range mentioned above. If air or the like is involved between the protective surface and the thin object, it is necessary to perform thermocompression bonding using a hot press, a hot roll, or the like. Heating temperature is 3
Although it is possible to obtain products with sufficient adhesion even below 00°C, if heat resistance is required, the temperature as high as possible (
Usually, it is preferable to carry out pressure bonding at a temperature of 200 to 300 degrees Celsius. By carrying out heat pressure bonding at a temperature 10 to 20 degrees Celsius higher than the required heat resistance temperature, a thin article with good heat resistance and adhesiveness can be obtained.

The printed circuit board of the present invention can be manufactured by providing a conductive metal layer on the laminate obtained as described above.

To obtain this conductive metal layer, a method of vapor depositing metal,
Examples include a method of electroless plating and a method of combining electroless plating and electrolytic plating.

(1) Vapor deposition As a method for vapor depositing the metal, commonly used resistance heating, vacuum heating vapor deposition such as electron beam heating, 1M conduction heat, thermal radiation heating, or sputtering can be applied. Examples of metal vapor deposits used include metals such as aluminum, gold, copper, nickel, and platinum, as well as alloys containing these as main components (50% by weight or more) (e.g., stainless steel), especially for microcircuits. Platinum and gold are often used, but when forming a circuit by etching after forming a thin film, copper, aluminum, and alloys containing these as main components are preferably used.

The thickness of the deposited conductive thin film can be freely selected depending on the conditions of the equipment used, but is usually 100 Angstroms to 100 microns, preferably 1000 Angstroms to 20 microns.

Furthermore, copper, nickel,
It is also possible to electroplate a metal such as gold to protect the surface and prevent corrosion, or to apply solder on the conductive path through a solder bath.

A so-called full additive method is also possible in which one circuit is formed by vapor deposition on the surfaces of the metal or alloy plate and ceramic layer and on the inner surfaces of the through-holes by the vapor deposition carried out in the present invention. Generally, the insulating material used in the fully additive method is one coated with an adhesive on the surface, but the insulating material of the present invention is made of ethylene-acrylic acid copolymer and/or ethylene-methacrylic acid copolymer "Thin material obtained from a mixture consisting of an acid copolymer and a saponified product of ethylene-vinyl acetate copolymer"
(hereinafter referred to as "rE-E thin material") has excellent adhesion to the deposited material without using an adhesive. Furthermore, it is possible to form conductor circuits by common circuit forming methods, such as cutting E-E thin materials to specified dimensions and drilling holes (punching method, drilling method, and pressing method). Then, pattern formation is by screen printing with a negative pattern or by masking unnecessary parts with a photosensitive agent. By depositing this masked E-E thin film, a metal deposited film having a specified thickness is formed on the unmasked circuit portion, thereby forming a pattern. Excellent alkali resistance is a necessary condition for long-term immersion in mask printing.

Usually, it is possible to form a layer that serves as both a photosensitizer and an adhesive, which is used in the commonly used full additive method, and then expose this layer to light to make it easy to bond and form a vapor deposited film only on the circuit area. It is being done. but,
The printed wiring board of the present invention does not require the use of these materials, and the directly vapor-deposited metal film layer has good adhesion and adhesion on the surface of the thin E-E material, making it suitable for mass production. (1) Ordinary etching has no drawbacks (such as generation of whiskers and pattern breakage), and it is possible to form precise circuits. After vapor deposition, corrosion prevention for circuit protection, and even IC
It is also possible to plate with gold, tin, solder, etc. to mold the chip.

For the printed wiring board of the present invention, any of the fully additive adhesive printing method, adhesive photography method, and direct method can be used.

The feature is that the direct method can also be performed.

(2) Electroless plating Nickel plating, highly corrosion-resistant zinc/nickel alloy plating, copper plating, etc. are generally known as electroless plating, that is, chemical plating. The thickness is uniform on the surface of
Copper sulfate plating is usually put into practical use because it has excellent adhesion and ductility between the material (substrate) and the plating film, allowing a dense plating film to be obtained. According to this sulfuric acid steel plating, it is possible to obtain a product having fine crystals, leveling (uniform thickness), stable workability, and excellent physical properties.

Generally, in copper sulfate plating, copper sulfate and sulfur are used to supply metallic copper into the solution and improve the conductivity and uniform electrodeposition of the solution. Additionally, chloride ions (as a catalyst) and appropriate amounts of brighteners are used. In addition, polyoxyethylene and polyoxypropylene derivatives may be used to enhance leveling.A typical composition is to add 5 to 40 g of copper sulfate (CuSO.5HO) to the aqueous solution in step 11.

For example, caustic soda (NaOH), ammonium chloride (NHC1), etc. are used as an I adjustment agent (!l buffer), and to prevent abnormal precipitation of copper in an aqueous solution, for example, EDTA-2Na (ethylenediamine) is used. Sodium salt of tetraacetic acid) and formalin (IcHO) as a reducing agent are added. Furthermore, these chemistries (
It is also possible to electrolytically plate copper, nickel, gold, or other metals on conductive surfaces (paths) of electroless plating to protect the surface and prevent corrosion, or to place solder on conductive paths through a solder bath. It is.

This is a so-called full additive method in which one circuit is formed by electroless conductive plating on the surface of the thin object and the inner surface of the through hole by chemical plating carried out in the present invention, and it is etched like a laminate covered with copper foil. The feature is that no process is required. Generally, the insulating material used in the fully additive method has a plating catalyst added to it or has an adhesive coated on its surface, but the E-E of the present invention Thin-walled materials have excellent adhesion to electroless copper even without the use of catalysts or adhesives. Furthermore, it is possible to form a conductive circuit by a general circuit forming method, for example:
A thin E-E material is cut to specified dimensions and holes are made on the surface of a metal or alloy plate that has been thermally sprayed with ceramics (
Any of the punching method, drilling method, and press processing may be used), and then pattern formation is performed by screen printing with a negative pattern or by masking unnecessary portions with a photosensitive agent. This masked E-E thin object is placed in an electroless copper plating solution, and copper plating of a specified thickness is deposited on the unmasked circuit portions to form a pattern. Mask printing and photosensitizers must have excellent alkali resistance because they are immersed in electroless plating solution for a long time.

Usually, a layer is formed that serves as both a photosensitive agent and an adhesive, which is used in the commonly used full additive method, and by exposing this layer to light, only the circuit area becomes a layer that is easy to bond and deposit electroless copper plating. things are being done. However, in the printed circuit board of the present invention, there is no need to use these, and the electroless copper plating layer is directly formed on the surface of the E-E thin object with good adhesion and adhesion, making it suitable for mass production. Not only is it possible to form precise circuits using normal etching without any defects (such as hair formation or pattern breakage). After chemical plating, it is also possible to plate with gold, soot, powder, etc. for corrosion prevention for circuit protection and for molding IC chips.

The printed circuit board of the present invention can be used with any of the fully additive adhesive printing method, adhesive photography method, and direct method, but the greatest feature is that the direct method can be used.

Hereinafter, the printed circuit board of the present invention, the laminate used for manufacturing this printed circuit board, and the printed circuit board will be explained with reference to the drawings.

FIG. 1 is a partially enlarged cross-sectional view of a representative example of the printed circuit board of the present invention. Moreover, FIG. 2 is a partially enlarged sectional view of a typical example of the laminate used to manufacture this printed circuit board.

In these figures, 1 is a metal or alloy plate,
2 is a ceramic layer obtained by thermal spraying. Moreover, 3 is a crosslinked product of E-E thin material. Furthermore, 4 is a conductive metal layer. The printed circuit board shown in Figure 1 was obtained by the direct method of the full Φ additive method, but it could also be obtained by any of the other methods such as adhesive printing, adhesive photography, and vacuum evaporation. Of course, it is possible to manufacture it.

In manufacturing the printed circuit board of the present invention, there is no need to further use an adhesive commonly used between the ceramic layer and the conductive metal layer, which not only omits the adhesive application step but also The insulating adhesive resin layer exhibiting thermoplastic properties does not cause blistering during heating due to volatile substances (e.g. organic solvents) contained therein. It undergoes a crosslinking reaction by heat treatment and becomes a thin, crosslinked product, which has the advantage of significantly improved heat resistance.

- The present invention will be explained in more detail below with reference to Examples.

In addition, in the Examples and Comparative Examples, the heat resistance test was performed using the obtained film as UL 79B (printed wiring board).
7.1 A copper-clad reprinted board consisting of a ceramic layer with the test pattern shown in Figure 1 was held at 220°C.
t, Lead/M = 55/45 (Ilf amount ratio) Lead/Tin held in a certain solder bath and 300°C = 90710 (
It was evaluated by floating it in a solder bath for 180 seconds (weight ratio).

Examples 1 to 6, Comparative Examples 1 to 6 Melt flow index (measured according to JIS -6760 at a temperature of 190°C and a load of 2.1 ekg, hereinafter referred to as "Ni, ■") is 300 g /
Ethylene-acrylic ugly copolymer (density 0J
54 g/C, obtained by saponifying ethylene-vinyl acetate copolymer with 100 parts by weight of acrylic acid copolymerization ratio of 20% by weight (hereinafter referred to as "rEA^") and vinyl acetate copolymerization ratio of 28% by weight. (saponification degree 97.5%, M, 1.75 g/10 min.

Density 0.951 g/cm", hereinafter "saponified material"
100 parts by weight of 5 parts by weight using a Henschel mixer
The mixture [hereinafter referred to as “mixture
(A)" was produced. Also, instead of the ethylene-acrylic rigid copolymer used in producing the mixture (A), M, 1. Ethylene-methacrylic copolymer with a density of 200 g/1G (density 0.950 g/1G)
e m', methacrylic acid copolymerization ratio 25% by weight) was used in the same manner as mixture (A) [hereinafter referred to as "mixture (
B)" was manufactured.

The mixture (A) thus obtained, the mixture, and the EA^ and saponified material used to produce the mixture (A) were each put into an extruder (diameter: 40 mm) equipped with a T-die.
a+s, dice Ill! A film (thickness: 20 microns) was molded using a cylinder (30 cm, rotation speed: 85 revolutions/min) under the conditions shown in Table 1 for the cylinder temperature.

Each film thus obtained was heated at 250°C and
2 each using a heat press machine at 00℃ for 10 minutes each.
Ceramics are laminated on the surface of a metal or alloy plate whose type and thickness are shown in Table 2 as shown in Figure 2 at 0 kg/cm" (gauge pressure). The properties of the film produced as described above are shown in Table 1, and the results of the heat resistance test of the laminate were bonded (layer A) at the bonding temperatures shown in Table 2. Table 2 shows that in Examples 5 and 6, the film obtained in Example 3 was used as the adhesive layer, and in Comparative Example 6, the commonly used epoxy resin (adhesion - spray plate) was used as the adhesive layer. “A 11 is an aluminum plate (thickness
1.0mm) Low soda alumina (A 203 content 8
8.8% by weight, true density 3. The thickness obtained by sintering l31 g / Cm', average a[0,8 micron] is 1. °B” means silicon carbide (α-5in, true density 3.22g/cm
", average grain size 2 microns)" refers to a silicon carbide plate with a thickness of 0.5 mm obtained by sintering.

In addition, 11 C11 is made of gray alumina CAJL203 = 98% by weight on a silicon steel plate with a thickness of 1.5 mm, ↑
f02 = 2.3% by weight) to a thickness of approximately 1 micron, and 'D' refers to a plate obtained by plasma spraying alumina sprayed plate of A above with an epoxy adhesive. It means something that is glued.

In addition, in Comparative Examples 1 to 3, as shown in Table 1,
Gel was generated on the surface of the resulting film, making it impossible to manufacture printed circuit boards.

Each of the laminates thus obtained was masked except for the circuit using a screen printing machine.

The obtained laminate was plated at 72°C with a chemical plating solution having the following composition in an aqueous solution of 11.
A 0 micron copper plating film was obtained.

CuSO4/ 5H2010g EDTA・2Na・2H2030g HC:HO (36g)
3mJINaOH12g After plating was completed, the masking was washed off, washed with water, and dried ("plating" is written in the "Conductive metal" column of Table 2).

In addition, a laminate obtained in the same manner was coated with 2×10
Platinum was deposited in -8 torr to obtain a metal film with a thickness of 1000 mm ("vacuum deposited" is written in the column "Conductive metal" in Table 2).

A heat resistance test was conducted on each printed circuit board thus obtained. The results are shown in Table 2.

(Hereinafter, blank space) The film obtained in Example 3 was rated according to JIS K-81311.
Volume resistivity, dielectric constant (IM&), dielectric loss tangent, and withstand voltage were measured according to the following.

The volume resistivity is 1014Ω・cm and the dielectric constant is 3.5
Met. In addition, the dielectric loss tangent is 0.2, and the withstand voltage is 2.
From the above results, the crosslinked product of the present invention (thin walled product obtained by heating and pressurizing the mixture) only has good adhesion to metal or alloy plates on which ceramics have been sprayed. Not,
It also has excellent heat resistance.

Moreover, it is clear that it can be used as a wiring board for ceramic spaces because of its good electrical insulation properties.

The printed circuit board obtained by the present invention not only has good heat resistance and heat dissipation as described above, but also has significantly improved reliability of electrical insulation, and has excellent cross-linking ability and adhesion when pressurized at high temperatures. It exhibits typical effects as it was invented based on an idea completely different from that of conventional heat-resistant polymer chemistry.

(1) Since the crosslinked material layer is thermally bonded to the ceramic layer of the substrate in which the ceramic layer is provided on a metal or alloy plate, an insulating layer with a uniform thickness and surface can be obtained. Therefore, fine-patterned circuits can be drawn using inexpensive methods such as direct plating.

(2) Excellent electrical properties (for example, insulation, withstand voltage, and dielectric loss tangent performance) and heat dissipation.

(3) It has good heat resistance and can not only withstand temperatures of 250°C or higher, but also can be applied without using the adhesive by applying pressure at temperatures of 100°C or higher. It can be bonded well to metal or alloy plates. For this reason, it not only fully demonstrates the heat dissipation properties of ceramics, but also
It is ideal for high-density mounting because it takes full advantage of its small dimensional change performance.

As described above, the printed circuit board of the present invention not only has good electrical properties such as insulation resistance and dielectric constant, but also has good heat dissipation, dimensional stability, heat resistance, chemical resistance, moisture resistance, etc. It also has features such as the ability to draw circuits on the substrate by plating or vacuum deposition.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a portion of a typical example of a printed circuit board on which a circuit is formed by vacuum deposition, plating, etc., as shown in FIG. 2, which will be described later. Further, FIG. 2 is an enlarged sectional view of a portion of a typical example of a printed circuit board having a structure in which a crosslinked material is laminated on one side of a metal or alloy plate with ceramics sprayed on it. 1... Metal or alloy plate 2... Ceramic layer 3... Crosslinked material 4... Conductive metal layer (depicted by vacuum evaporation, plating, etc.) circuit)

Claims (1)

[Scope of Claims] (A) a plate of aluminum, copper or iron or an alloy of these metals, (B) a ceramic layer, (C) (1) an ethylene-acrylic acid copolymer and/or an ethylene-methacrylic acid copolymer A crosslinked layer of a mixture of a polymer and (2) a saponified ethylene-vinyl acetate copolymer and (D) a conductive metal layer are sequentially laminated, and the thickness of the metal or alloy plate is 0. 1 to 5 mm, the thickness of the ceramic layer is 100 Å to 10 mm, the crosslinked product contains at least 80% by weight of residues with a diameter of 0.1 micron or more after extraction treatment with boiling toluene for 3 hours, and of ethylene-
The mixing ratio of the acrylic acid copolymer and/or the ethylene-methacrylic acid copolymer is 20 to 80% by weight, the thickness of this layer is 0.2 microns to 1000 microns, and the thickness of the conductive metal layer is The width is 100Å to 200Å
micron, and this layer is formed by any one of metal vapor deposition, electroless plating, and a combination of electroless plating and electrolytic plating.