JPS62247587A - Manufacture of ceramic 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 [Field of Industrial Application] The present invention relates to a method of manufacturing a ceramic substrate, and more particularly to a method of manufacturing a ceramic substrate having a conductor circuit.

[Conventional technology]

The core layer of the eggplant is made from scratch, and the mainstream manufacturing method is the screen printing method using conductive paste. The following points have been pointed out as problems with this method.

10 Various screens are required depending on the shape of the pattern to be formed, making it difficult to change the pattern. Therefore, the time and expense required for changes will increase.

(2) The use of a screen causes phenomena such as bleeding of patterns and disturbance of edges, making it difficult to form fine lines.

(3) Since the drying time of the pattern is relatively long, when it is desired to form overlapping patterns, it is necessary to provide sufficient drying time, resulting in poor workability.

(4) Screen printing on a substrate with a curved surface is very difficult.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is to solve the above-mentioned difficulties in the conventional manufacturing method of a ceramic substrate having a conductive circuit.

[Means for solving problems]

This problem was solved by forming a composition layer on a transparent sheet, which consists of a binder whose main components are money luck powder, inorganic powder (excluding money luck powder), and ultraviolet curable resin, and then forming a mask film over it. After that, the bonding material is cured by irradiating ultraviolet rays from above, and after development, the uncured portion is removed to form a circuit pattern. Then, the ceramic green sheet composition is applied onto the circuit pattern, dried, and fired. This is achieved by

[Function and structure of the invention]

In the present invention, a desired pattern is formed without using a screen at all, so all the problems caused by using a screen are eliminated. That is, using a binder made of metal powder, inorganic powder (excluding metal powder, the same applies hereinafter), and ultraviolet curing resin, a mask film is used to irradiate and cure ultraviolet rays so that only the desired pattern can be irradiated with ultraviolet rays. In addition, since a means for removing the uncured portion after development is adopted, a desired pattern can be formed without using a screen at all as in the conventional method.

For this reason, the disadvantages based on the use of screens, namely the above (1)
), (2) and (4) are solved before they occur.

In addition, since such an ultraviolet curable binder is used, the curing is significantly faster than with conventional methods, and the above (3)
The difficulty of is solved.

In the method of the present invention, first, a binder layer consisting mainly of money powder, inorganic powder, and ultraviolet curing resin is formed on a transparent sheet. The metal powder in this case is used to construct the circuit pattern, and therefore, the gold luck powder used here is widely used to construct the circuit pattern, and specifically, for example, gold, platinum, silver, copper,
These include aluminum, tin, nickel, tungsten, molybdenum, etc., and alloys such as gold-platinum, silver-platinum, and silver-palladium may also be used as mixed powders if necessary. The particle size of metal powder is generally 0.1 to 30.1
7 m, preferably about 0.5 to 5 pm.

Inorganic powders are used for the purpose of improving adhesion to ceramic substrates during firing, and are widely used as long as they can improve adhesion, such as A120.
3, S iO2, M g Os T i O-Cr2
O3, talc, etc. may be used alone or in combination, and glass frit etc. may also be used.

The particle size of the inorganic powder at this time is usually about 0.1 to 10 μm.

The binder of the present invention is a resin composition comprising an ultraviolet curable resin, an initiator, and various additives as required. As the ultraviolet curable resin, resins that can be cured by ultraviolet light are used, such as epoxy resin, epoxy acrylic resin, urethane acrylic resin, polyester acrylic resin, alkyd acrylic resin, silicone acrylic resin,
Examples include polyene/polythiol-based spiran resins and amino alkyd resins. Conventionally used photoinitiators are used as initiators to be added to the above-mentioned ultraviolet curable resin, such as Lewis acid diazonium salts, Lewis acid sulfonium salts, Lewis acid iodonium salts, benzophenone compounds, hensifhenone/amine compounds. , acetophenones, benzoin ethers, p-benzoylbenzyl chloride, etc., and one or more of these may be appropriately selected and used depending on the type of ultraviolet curing resin. The amount used in this case is usually about 0.5 to 10 ffl parts per too many parts of the ultraviolet curable resin.

Further, if necessary, ordinary additives such as colorants and anti-aging agents may be added in addition to the ultraviolet curable resin and the photoinitiator.

As mentioned above, the binder in the present invention is mainly composed of money powder, inorganic powder, and ultraviolet curing resin, and the blending amount of each of these is 100 parts by weight and 9 parts by weight of the total amount of both powders. 3 to 50 parts by weight, preferably 5 to 3 Off! f
This is part f1. However, the mixing ratio of the metal powder and the inorganic powder is 3 to 50 parts by weight, preferably 5 to 20 parts by weight, per 100 parts by weight of the money luck powder.

This bonding material is formed on a transparent sheet to a thickness of usually about 5 to 100 .mu.m, preferably about 10 to 50 .mu.m, either as it is or by adding a suitable solvent if necessary.

As the transparent sheet, polyester, polyvinyl chloride, nylon, polyethylene, polypropylene, EVA, etc. can be used. Film thickness is 10-100
It is about μm.

A mask film is placed on top of the transparent sheet with the powder sheet layer prepared in this way, and ultraviolet rays are irradiated from above.
Curing, developing, and cleaning are performed. In the method of the present invention, since a mixture of an ultraviolet curable resin and metal powder is used as the binder layer, the transmittance of ultraviolet rays may be slightly lowered. For this reason, as shown in FIG. 1, it is preferable to use the mask film on the transparent film side and irradiate the ultraviolet rays from above, whereby a fine pattern can be obtained. The mask film is used to form a desired circuit pattern, and materials that can block ultraviolet rays are widely used.

Next, a ceramic gelene sheet composition is applied onto the patterned transparent sheet.

As is well known, a ceramic green sheet composition is a mixture of ceramic powder and a binder mixed and dispersed in an organic solvent or water.

As the above-mentioned ceramic powder, powder with an average particle diameter of about 0.1 to 10 μm is used, which is made of various known ceramics such as alumina powder, beryllia powder, stearite powder, barium titanate powder, and magnesium titanate powder. . Moreover, various resins or rubbery polymers such as ethyl cellulose, nitrocellulose, and poly(meth)acrylic acid alkyl ester resins are used as the binder.

The amount of binder used is preferably such that its proportion in the total amount with the ceramic powder is generally about 4 to 30% by weight; if it is too large, it is difficult to obtain good results in the density and quality of the fired ceramic. .

Any organic solvent may be used as long as it can dissolve the above-mentioned binder, and specifically, xylene, toluene, buknol, etc. are used. Water-soluble ones are particularly preferred.
In addition, in addition to the above-mentioned components, the above-mentioned ceramic composition contains arbitrary components such as talc, CaOlMgO, Si○, 5i02, etc., and these arbitrary components are contained in the ceramic green sheet. However, the amount used is preferably 15ffi11% or less of the total amount of the sheet.

The green sheet composition may be applied onto the patterned transparent sheet by any method such as a doctor blade method or a roll coater method.

However, care must be taken to ensure that this coating does not cause deformation of the pattern formed by the above method.

The green sheets formed in this manner may be punched out or stacked to form a multilayer structure.

Next, when subjected to a firing step and heat-treated at a high temperature, the organic binder of the ceramic green sheet and the conductive powder layer is carbonized and disappeared, and a ceramic substrate having a conductive circuit with excellent adhesion between the two is obtained. The heating temperature in the firing process is determined appropriately depending on the ceramic powder in the ceramic green sheet and the M type of the conductor powder layer, but is generally 1000 to 180.
The temperature may be appropriately selected within the range of about 0°C depending on the type of powder.

The atmosphere during firing may be an oxidizing gas atmosphere (including air) or a non-oxidizing gas atmosphere such as a vacuum system or a hydrogen gas atmosphere, depending on the type of each powder mentioned above.For example, if the ceramic substrate is alumina powder, If the conductor powder is platinum powder, an oxidizing gas atmosphere can be used, and if the conductor powder is molybdenum powder, a non-oxidizing gas atmosphere can be used.

By the above method, a ceramic substrate having a highly accurate conductor circuit can be easily obtained.

〔Example〕

EXAMPLES Below, examples of the present invention will be described in more detail. However, in the following examples, parts refer to m9 parts.

Examples 90 parts of tungsten powder (average particle size 1.5 μ), 6 parts of alumina powder (average particle size 2 μ), 2 parts of magnesia powder (average particle size 2 μ), 2 parts of calcia powder (average particle size 2 μ), UV curing After mixing 15 parts of H resin (mixed with 1 part of benzophenone as a photoinitiator to 100 parts of epoxy acrylic resin) and 20 parts of methyl ethyl ketone as a solvent at room temperature, the mixture was placed on a polyester film separator (thickness 50 μm). A powder sheet was formed by coating the powder sheet to a film thickness of 30 μm.Next, a mask pattern was formed on the film side of the powder sheet, and irradiation was performed with an ultra-high pressure mercury lamp.
The resin was cured by irradiating with ultraviolet light at 000 mJ/cm2. Furthermore, a 1.5% aqueous sodium carbonate solution was used as a developing solution, and after immersing the film in the solution for 90 seconds, the uncured portion was washed with distilled water and the film was dried to form a conductor circuit pattern.

Next, 93 parts of alumina powder (average particle size 2 μm), 7 parts of talc
parts, polymethyl methacrylate 5 parts, and xylene 100 parts
A ceramic composition consisting of 2 parts was mixed in a ball mill and coated onto a polyester film by a doctor blade method.

Next, the polyester film was peeled off and baked at 1600° C. for 130 minutes in a hydrogen gas atmosphere.

The appearance of the obtained ceramic substrate was good, and the adhesion between the substrate and the conductor was also good.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a method of mounting a mask sheet when a mask film is stacked on a transparent sheet on which a binder layer is formed and irradiated with ultraviolet rays, which is one step of the method of the present invention. (1)...Transparent sheet (2)...Binding material layer (3)...Mask film (or more)

Claims (1)

[Claims] (1) Metal powder, inorganic powder (excluding metal powder),
A composition layer consisting of a binder mainly composed of and an ultraviolet curing resin is formed on a transparent sheet, a mask film is overlaid, and then ultraviolet rays are irradiated from above to cure the binder,
A method for manufacturing a ceramic substrate, comprising: removing uncured portions after development to form a circuit pattern; then coating a ceramic green sheet composition on the circuit pattern, drying and firing.