JPH0946044A - Method for manufacturing laminated ceramic circuit board - Google Patents

Abstract

(57) An object of the present invention is to provide a method for manufacturing a laminated ceramic circuit board in which the shape of a via-hole conductor is stable and is not affected by surface irregularities of a supporting board. SOLUTION: A colored substrate smoothing layer 16 is formed on a supporting substrate 15, and a coating film 10 is formed on the supporting substrate 15 by coating or printing / drying a ceramic slip material.
First step of forming a to 10e, selective exposure treatment
A second step of forming a through hole by a developing process, a conductor forming a via hole conductor in the through hole of the coating film, and a conductor film forming an internal wiring conductor on the coating film by a printing / drying process of a conductive paste. 3 is sequentially performed to form a laminate, and the substrate smoothing layer 1 is formed on the supporting substrate 15.
A method for manufacturing a monolithic ceramic circuit board, comprising the steps of peeling the laminated body containing 6 and firing the laminated body and simultaneously burning away the substrate smoothing layer 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated ceramic circuit board using a ceramic slip material containing a photocurable monomer.

[0002]

2. Description of the Related Art The present applicant has previously proposed a method for manufacturing a laminated ceramic circuit board using a ceramic slip material containing a photocurable monomer.

Specifically, a ceramic slip material obtained by homogeneously mixing ceramic powder, glass frit, a photo-curable monomer, an organic binder, a solvent and the like is applied or printed on a supporting substrate or the like and dried to form an insulating layer. A first step of forming a coating film, a second step of selectively exposing and developing the coating film to form a through hole to be a via hole conductor, and a conductive paste is printed and filled in the through hole. To form a conductor to be a via-hole conductor and, if necessary, to print a conductive paste on the coating film and dry it to form a conductor film to be an internal wiring conductor. Is formed, and the laminate is fired.

In practice, the lowermost insulating layer of the laminate is formed by a coating film formed on a supporting substrate made of a ceramic or resin film, and the next coating film is a coating film formed before. Will be formed on each.

In the second step, the selective exposure treatment cures only a part of the coating film exposed to the exposure light, and the portion not exposed to the exposure light is removed by the next development treatment. As a result, through holes are formed in the coating film. Therefore, the shape of the through-hole can be arbitrarily formed by controlling the selective exposure process, and even if the through-hole is filled with the conductive paste in the third step, the supporting substrate and the coating already formed are formed. Since the conductive paste does not come off due to the film, a via hole conductor having high connection reliability and high conductivity is formed.

In addition, in the third step, when the coating film which is the uppermost layer is processed, it is only necessary to form the conductor which becomes the via hole conductor, but the surface wiring conductor of the laminate is formed at the same time as the firing of the laminate. When forming, a conductor film to be a surface wiring conductor may be formed in advance.

The supporting substrate is made of a ceramic or a resin film, and after the first to third steps are repeated to form a laminated body portion, the laminated body is peeled from the supporting substrate and fired.

When the laminate is peeled from the above-mentioned support substrate, the peelability between the laminate and the support is particularly enhanced, and the surface shape of the support substrate does not adversely affect the lowermost insulating layer of the laminate. As described above, the present applicant also proposes a manufacturing method in which the substrate smoothing layer is formed on the supporting substrate. This substrate smoothing layer was made of acrylic polyester resin or the like.

[0009]

However, in the first step, the ceramic slip material is applied or printed and dried to form a coating film to be a ceramic layer. The stability of the through-hole formed in the exposure process and the development process in the second step largely affects. Rapid drying will cause cracks on the surface of the coating film of the strip material, so avoid this and set the drying conditions, but if drying is insufficient, overall,
There is a problem that a large amount of solvent remains in the coating film (solvent excess), and when the through hole is formed, the dissolution progresses to a portion other than the predetermined formation position.

On the other hand, if the film is excessively dried, the film becomes too dense, and it becomes difficult for the developer to permeate, resulting in insufficient development (removal).

The present invention has been devised in view of the above-mentioned problems, and an object thereof is to provide a method for manufacturing a laminated ceramic circuit board capable of accurately forming a through hole to be a via hole conductor. Especially.

[0012]

According to a first aspect of the invention, a ceramic slip material composed of a ceramic filler, a glass frit, a photocurable monomer, an organic binder and a solvent is applied or printed / dried on a supporting substrate. A first step of forming a coating film to be a layer, a second step of forming a through hole in the coating film by selective exposure treatment / development processing, and a via hole conductor by printing and filling a conductive paste into the through hole. Forming a conductor, and forming a conductor film to be an internal wiring conductor on the coating film by printing and drying a conductive paste. Repeating the first to third steps to stack the conductor film. In the method for manufacturing a laminated ceramic circuit board, which comprises forming a body and firing the laminated body formed on the supporting substrate, the ceramic layer is formed. Nunomaku is a method for producing a multilayer ceramic circuit board obtained by removing 85～97Wt% of the total solvent of the ceramic slip material by drying.

[0013]

According to the present invention, the coating film in the first step, that is, after the coating or printing of the ceramic slip material and the dry treatment, is 85 to 9% of the total solvent of the ceramic slip material.
7 wt% is removed. Therefore, excessive development in the second step due to insufficient drying can be effectively suppressed. In addition, it prevents densification of the coating film due to overdrying,
The insufficient development in the second step can be effectively suppressed. With this, it is possible to easily form the through hole having the predetermined hole shape with high accuracy by the developing process.

As a result, the connection between the via-hole conductor of the laminated ceramic circuit board and the internal wiring conductor can be made extremely reliable.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a laminated ceramic circuit board according to the present invention will be described below with reference to the drawings. FIG.
It is sectional drawing of the laminated ceramic circuit board which concerns on this invention.

In FIG. 1, reference numeral 10 denotes a monolithic ceramic circuit board. The monolithic ceramic circuit board 1 is a laminated body 1 having internal wiring conductors forming a predetermined circuit therein, and a surface wiring conductor formed on the surface of the laminated body 1. 4, 5, a thick film resistor film 6 connected to the surface wiring conductors 4, 5 as necessary, various electronic components 7, and the like.

The laminated body 1 comprises ceramic layers 1a to 1e,
Internal wiring conductors 2 for achieving a predetermined circuit network and for generating a capacitance component are arranged between the ceramic layers 1a to 1e. In addition, a via-hole conductor 3 is formed in each of the ceramic layers 1a to 1e so as to penetrate in the thickness direction of the layer.

The ceramic layers 1a to 1e are, for example, 850.
It consists of a glass-ceramic material that allows firing at relatively low temperatures around 1050C. Specific ceramic materials include cristobalite, quartz, corundum (α
Alumina), mullite, cordierite and the like can be exemplified. In addition, by firing a glass frit containing a plurality of metal oxides as a glass material, at least one kind of crystal of cordierite, mullite, anorthite, Celsian, spinel, garnite, willemite, dolomite, petalite or a substituted derivative thereof is obtained. Is deposited. The thickness of the ceramic layers 1a to 1e is, for example, about 10 to 100 μm.

The internal wiring conductor 2 and the via-hole conductor 3 are A
The internal wiring conductor 2 has a thickness of about 8 to 15 μm, and the via-hole conductor 3 has an arbitrary diameter. The internal wiring conductor 2 has a thickness of about 8 to 15 μm, and the internal wiring conductor 2 has a thickness of about 8 to 15 μm. However, the diameter is, for example, 80 to 250 μm.

Surface wiring conductors 4 and 5 are formed on both main surfaces of the laminate 1. The surface wiring conductor 5 on the upper surface side of the laminated body 1 in the figure is formed by baking on the surface of the laminated body 1, and the surface wiring conductor 4 on the lower surface side of the laminated body 1 in the figure is embedded in the ceramic layer 1e. Are formed as described above and are flush with the surface of the ceramic layer 1e. The surface wiring conductors 4 and 5 are made of Ag-based (Ag simple substance, Ag alloy such as Ag-Pd) or Cu-based (Cu simple substance, Cu alloy) conductors.

Further, the surface wiring conductors 4 and 5 are made of a Cu-based material, which has excellent migration resistance and enables high density. Incidentally, in the case of a copper-based conductor, it is necessary to perform baking in a reducing atmosphere or a neutral atmosphere. When firing the laminated body 1 at the same time as firing, a material that can be fired under the firing conditions of the internal wiring conductor 2, for example, a silver-based conductor material is used.

The surface wiring conductors 4 and 5 include an input / output terminal portion and an electronic component mounting pad, and a thick film resistor film 6 and an insulating protective film are formed as necessary.

The surface wiring conductors 4 and 5 of such a laminated body 1
A thick-film resistor film 6 is formed on the substrate, and various electronic components 7 such as a chip-shaped capacitor, a chip-shaped resistor, a transistor, and an IC are mounted by soldering, wire bonding, or the like.

A method of manufacturing the above-mentioned laminated ceramic circuit board will be described.

The method for manufacturing the laminated ceramic circuit board 1 is as follows.
The process is roughly divided into a preparation process before lamination, and a laminate forming process including first to third processes, a peeling process, a firing treatment process, and a surface treatment process.

In the preparation step, the support substrate 15, the ceramic slip material of the ceramic coating film to be the ceramic layers 1a to 1e, the internal wiring conductor 2, the via-hole conductor 3, and the conductive paste of the conductor film or the conductor to be the surface wiring conductor 5 are prepared. It is a process of preparing each.

[Supporting Substrate] As shown in FIG. 2A, the supporting substrate 15 is a substrate made of ceramic, glass, heat-resistant resin, or the like. The substrate smoothing layer 16 is formed.

The substrate smoothing layer 16 is formed by applying and drying a slip material obtained by homogeneously kneading an organic binder, a photocurable monomer, a coloring agent and a solvent to form a coating film, and then exposing the entire surface of the coating film to light exposure. It is formed by curing. The thickness of the substrate smoothing layer 16 is at least thick enough to absorb the irregularities of the supporting substrate 15, for example, 20 μm or more.

Here, the organic binder has excellent thermal decomposability so that it can be burned out at a relatively low temperature and in a short-time firing step, and at the same time, it determines the viscosity of the slip, and therefore acrylic acid or methacrylic acid is used. An ethylenically unsaturated compound having a carboxyl group and an alcoholic hydroxyl group such as an acid polymer is preferable.

The photo-curable monomer has excellent thermal decomposability so that it can be burned out at a relatively low temperature in a short baking step, and it is photopolymerized by exposure after coating and drying of the slip material. A monomer having a secondary or tertiary carbon, which is capable of forming free radicals and chain-growth addition polymerization, is preferable, for example, an alkyl acrylate such as butyl acrylate having at least one polymerizable ethylene group. And their corresponding alkyl methacrylates are effective. In addition, polyethylene glycol diacrylates such as tetraethylene glycol diacrylate and methacrylates corresponding to them can be mentioned.

The ratio of the photo-curable monomer to the organic bander is about 1 to 3: 5.

The colorant can be exemplified by an azo-based or anthraquinone-based dye, and the substrate smoothing layer 16 formed by this exhibits a color with high light absorption such as red, brown, green or blue.

As the solvent, an organic solvent or an aqueous solvent can be used. In the case of an aqueous solvent, the photocurable monomer and the organic binder must be water-soluble,
A hydrophilic functional group such as a carboxyl group is added to the monomer and the organic binder. The amount of addition is 2 to 300, preferably 5 to 100, when expressed by acid value.

In the above slip material, the photo-curable monomer and the organic binder must be completely pyrolyzed in the process of firing the laminate as described above.
A material is selected that decomposes at a temperature of ≤C, preferably of ≤500C.

Further, a sensitizer, a photoinitiating material, etc. may be added to the slip material, if necessary. For example, examples of the photoinitiator-based material include benzophenones and acyloin ester compounds.

As a method of applying the slip material, for example,
A doctor blade method (knife coating method), a roll coating method, a printing method and the like can be mentioned. In particular, a doctor blade method or the like is preferable because the surface of the substrate smoothing layer 16 can be easily flattened. The amount of the solvent added is adjusted according to the coating method to adjust the viscosity to a predetermined value.

As a drying method, a batch-type drying furnace or an in-line-type drying furnace is used, and the drying condition is 120 ° C.
The following is desirable. Further, since rapid drying may cause cracks on the surface, it is important to avoid rapid heating.

The exposure treatment is a negative type in which the photo-curable monomer contained in the coating film is photo-polymerized, so that the entire surface of the coating film is irradiated with low-pressure, high-pressure, and ultra-high-pressure mercury lamp exposure light. The exposure conditions are such that the exposure light of 10 to ²⁰ mW / cm ² is irradiated for about 5 to 30 seconds. As a result, the coating film is photocured by causing a photopolymerization reaction of the photocurable monomer.

Although the colored substrate smoothing layer 16 is provided on the surface of the supporting substrate 15 described above, the substrate smoothing layer 16 may be omitted by subjecting the supporting substrate 15 itself to a coloring treatment. I do not care. Specifically, a supporting substrate made of a polyester resin containing the above coloring material is used.

[Ceramic Slip Material] The ceramic slip material is formed by homogeneously kneading ceramic powder, glass frit, photocurable monomer, binder and solvent.

The ceramic powder is an insulating ceramic material such as cristobalite, quartz, corundum (α-alumina), mullite or cordierite, BaTiO ₃ , Pb ₄ F.
e ₂ Nb ₂ O _12, the dielectric ceramic material, such as TiO _2, Ni-Zn ferrite, (referred to ceramic in a broad sense) Mn-Zn ferrite Do to as magnetic ceramic material can be mentioned, its average particle size 1 0.0-6.0μ
m, preferably 1.5 to 4.0 μm. Note that two or more ceramic materials may be used in combination. In particular, the use of corundum is advantageous in terms of cost.

The glass frit is a glass frit as long as it crystallizes cordierite, mullite, anorthite, sergian, spinel, garnite, willemite, dolomite, petalite or a derivative thereof or a spinel structure crystal phase by firing treatment. Well, for example, B ₂ O
Examples thereof include glass frits containing ₃ , SiO ₂ , Al ₂ O ₃ , ZnO and alkaline earth oxides. Such a glass frit has a wide vitrification range and a yield point of 600 to
This is because the temperature is around 800 ° C., so that it is suitable for low temperature firing at about 850 to 1050 ° C., and the sintering behavior with the conductor film to be the internal wiring conductor 2 is similar. The average particle size of the glass frit is 1.0 to 6.0 μm, preferably 1.5.
Is about 3.5 μm.

The composition ratio of the above-mentioned ceramic material and glass material is such that when firing at a relatively low temperature of 850 to 1050 ° C., the ceramic material is 10 to 60 wt%, preferably 30 to 50 wt%. Is 90-40
wt%, preferably 70 to 50 wt%.

When the ceramic material is used in combination with a dielectric ceramic material or a magnetic ceramic material, the characteristic peculiarity of the ceramic material may be deteriorated. Therefore, glass frit is added as necessary.

The photocurable monomer is used for the substrate smoothing layer 16
The materials used for can be used. This is to make the exposure conditions substantially the same. The photocurable monomer is added in a predetermined amount so that the portion other than the exposed portion can be easily removed by the developing treatment after the exposure treatment. For example, 5 to 15w for solid components (ceramic material and glass material)
It is t% or less. For the binder, it is necessary to give importance to wettability with the solid content, and the material used for the substrate smoothing layer 16 can be used. The addition amount is preferably 25 wt% or less with respect to the solid content.

As the solvent, an organic solvent or an aqueous solvent can be used. In the case of an aqueous solvent, the photocurable monomer and binder must be water-soluble, and a hydrophilic functional group such as a carboxyl group is added to the monomer and binder.

The addition amount is from 2 to 300, preferably from 5 to 100, in terms of acid value.

When the addition amount is small, the solubility in water and the dispersibility of the powder of the fixed component deteriorate, and when the addition amount is large, the thermal decomposability deteriorates. Therefore, the addition amount depends on the solubility and dispersibility in water, Considering the thermal decomposability, it is appropriately added within the above range.

Further, a sensitizer, a photoinitiator material, etc. may be added to the slip material as required. For example, examples of the photoinitiator-based material include benzophenones and acyloin ester compounds.

[Conductive paste] The conductive paste is A
Conductive material powder such as g-based (Ag simple substance, Ag alloy such as Ag-Pd), Cu-based (Cu simple substance, Cu alloy), for example, silver-based powder, low melting point glass component, binder and solvent homogeneously kneaded Is used. Also, this paste may be used for the surface wiring conductor 5. The internal wiring conductor 2
In the conductive paste for the conductor film that becomes, the photocurable monomer used for the ceramic slip material may be added. When the conductive paste containing the photocurable monomer is used, the conductor film is printed and dried, or the conductor is filled and dried, and then photocured by an exposure process.

[Layered Body Forming Step] The laminated body forming step is a first step of forming a coating film to be a ceramic layer by coating or printing / drying a ceramic slip material containing a photocurable monomer, and the coating film. Second step of forming a through hole by selective exposure processing and development processing, forming a via hole conductor by printing and filling a conductive paste in the through hole, and printing and drying the conductive paste on the coating film. The third step is to form a conductor film to be an internal wiring conductor by processing. In addition, in the laminated body in the manufacturing process, a plurality of laminated body regions are formed at the same time so that a plurality of laminated bodies can be finally extracted, but here, only one laminated body region will be described.

First, the lowermost ceramic layer 1 of the laminated body 1
The ceramic coating film 10e to be e is formed in the first step. That is, as shown in FIG. 2B, a ceramic coating film 10e to be the ceramic layer 1e is coated on the substrate smoothing layer 16 of the supporting substrate 15 with the above-mentioned ceramic slip material by a doctor blade method or the like and dried (batch). Type drying oven or in-line type drying oven).

As a method of applying the slip material, for example,
A doctor blade method (knife coating method), a roll coating method, a printing method and the like can be mentioned. In particular, a doctor blade method or the like is preferable because the surface of the substrate smoothing layer 16 can be easily flattened. The amount of the solvent added is adjusted according to the coating method to adjust the viscosity to a predetermined value.

The drying method is 120 ° C. or lower, and depending on the thickness of the coating film, a drying treatment is carried out at 60 to 80 ° C. for 10 minutes to 30 minutes. 85
~ 92 wt% solvent is removed.

Next, in the second step, a through hole (actually, the lower hole opening is closed by the supporting substrate, which is hereinafter referred to as a through recess) 30 is formed in the ceramic coating film 10e as the via hole conductor 3. To do. That is, it is formed by the selective exposure process shown in FIG. 2C and the development process shown in FIG.

In the exposure process, since the through recess 30 is formed at the position which becomes the via hole conductor 3 penetrating the thickness of the ceramic layer 1e, the photo target having the predetermined conductor which is not irradiated with the exposure light is applied to only this part. Exposure conditions when the substrate smoothing layer 16 is formed by being placed close to or on 10e (10 to 20 m of low-pressure, high-pressure, and ultra-high-pressure mercury lamp system).
The exposure light of W / cm ² is irradiated for about 5 to 30 seconds).

In FIG. 2 (c), 32 is a photo target, the arrow indicates the exposure light, and the dotted portions of the coating film 10e are the portions that are photo-cured by the exposure processing.

In the development process, organic chlorocene, 1,1,1-trichloroethane, and a water-based alkaline developing solvent are sprayed onto the coating film 10e subjected to the selective exposure process, for example, by a spray developing method or a paddle developing method. Or contact or develop. Then, if necessary, washing and drying are performed.

By this selective exposure process and development process, the through recess 30 is formed in the coating film 10e at the position to be the via-hole conductor 3, and all the portions remaining by the development process are photo-cured. become.

The shape and diameter of the through recess 30 formed in the second step can be arbitrarily set by controlling the shape of the photo target. That is, it is possible to easily increase the size of the via-hole conductor 3 that connects between the wires for supplying a relatively large current, such as the power supply wires and the ground potential wires.

The exposure using the photo target is
Generally, since it is used for microfabrication of a semiconductor chip or the like, there is no positional deviation in the through recess 30 of the via hole conductor 3 formed by being controlled by the photo target, and the conduction reliability of the via hole conductor 3 is large. improves.

Next, in a third step, the through recess 30 of the coating film 10e is filled with the conductor 31 which becomes the via hole conductor 3, and the conductor which becomes the internal wiring conductor 2 between the ceramic layers 1e and 1d is formed. The film 20 is formed.

That is, as shown in FIG. 2E, the coating film 1
The conductor 31 serving as the via-hole conductor 3 is filled in the penetrating recess 30 by printing the above-mentioned conductive paste in the penetrating recess 30 of 0e by screen printing. In addition, the coating film 1
The conductor film 20 to be the internal wiring conductor 2 is formed by screen-printing the above-mentioned conductive paste on 0e in a predetermined shape. After that, a drying process is performed, an exposure process is performed if necessary, and a photocuring process is performed. The through recess 3
When the shape of 0 is large, first, the conductive paste may be filled in the through recess 30 with the conductor 31 using a dispenser or the like, and then the conductor film 20 to be the internal wiring conductor 2 may be formed by printing. .

Next, the first step to the third step are sequentially repeated to form a laminated structure on the supporting substrate 15 in which a conductor film to be the internal wiring conductors 2 ... And a conductor 31 to be the via hole conductor 3 are formed. Form a body (unfired). This state is shown in FIG.
It shows in (d).

In the third step performed on the coating film which is the uppermost layer of the laminated body, it is not necessary to form the internal wiring conductor, so only the conductor 31 that becomes the via-hole conductor 3 is filled. Also, at the end of the laminated body forming step, if necessary,
The dividing grooves may be formed by press molding or the like depending on the shape of each laminated body 1.

[Peeling Step] Next, as shown in FIG. 2F, the ceramic coating films 10 a to 10 a are removed from the support substrate 15.
e, the unfired laminated body including the conductor film 20 that becomes the internal wiring conductor 2 and the conductor 31 that becomes the via-hole conductor 3 is peeled off.

Here, even if part or all of the substrate smoothing layer 16 adheres to the laminate side, it will be completely burned out by the subsequent firing process.

A resin material which causes a foaming reaction at 120 ° C. (drying temperature) or higher is added to the substrate smoothing layer 16, or a resin layer which causes a foaming reaction on the surface of the substrate smoothing layer 16 is added. If provided, it can be easily peeled off by heat treatment at 120 ° C. or higher.

Further, by interposing a sheet that dissolves in an organic solvent at the interface between the supporting substrate 15 and the substrate smoothing layer 16, or by using a sheet that dissolves the supporting substrate 15 itself in an organic solvent, the sheet can be immersed in the organic solvent. Peeling may be performed. When using a sheet that dissolves in an organic solvent, it is important to use a ceramic slip material, a conductive paste as a binder, a photocurable monomer as an aqueous system, and a solvent as pure water.

[Firing Step] Next, the unfired laminate separated from the support substrate 15 is subjected to firing treatment. The firing process includes a binder removal process and a sintering process.

The binder removal process is performed by the ceramic coating film 10.
a to 10e, the conductor film 20 to be the internal wiring conductor 2, the conductor 31 to be the via-hole conductor 3, the organic components contained in the conductor film 50 to be the surface wiring conductor 5, and the substrate smoothing layer 16 are burned down. , For example, in a temperature range of 600 ° C. or lower.

In the sintering process, the coating films 10a to 10e are used.
The glass component of is crystallized and uniformly dispersed in the grain boundaries of the ceramic powder to give the laminate 1 a certain strength, and at the same time,
The conductive material of the conductor film 20 serving as the internal wiring conductor 2, the conductor 31 serving as the via-hole conductor 3, and the conductor film 50 serving as the surface wiring conductor 5, for example, silver-based powder is grain-grown to reduce the resistance, and at the same time, the ceramic layer is formed. It is to be integrated with 1a to 1e. This is done until a peak temperature of 850-1050 <0> C is reached.

The firing atmosphere differs depending on the material of the conductive paste. As described above, in the case of the Ag-based conductor, the atmosphere (oxidizing) atmosphere or neutral atmosphere is used, and in the case of the Cu-based conductor, the reducing atmosphere is used. It is performed in an atmosphere or a neutral atmosphere.

As a result, the coating films 10a to 10e become the ceramic layers 1a to 1e, the conductor film 20 becomes the internal wiring conductor 2, and the conductor 31 becomes the via-hole conductor 3 to achieve a large-sized laminated substrate.

When the laminate is peeled from the supporting substrate,
Even if a part or all of the substrate smoothing layer 16 is attached to the laminated body side, the organic binder component is completely burned out by this baking treatment.

[Surface Treatment Step] Next, surface treatment is performed on both main surfaces of the fired large-sized laminate substrate.

For example, a copper-based conductive paste is printed and dried so as to be connected to the via-hole conductors 3 formed in the ceramic layers 1a and 1e on both main surfaces of the large-sized laminate substrate.
The surface wiring conductors 4 and 5 are formed by baking. Here, the copper-based surface wiring conductors 4 and 5 are joined to the silver-based conductor via-hole conductor 3. Therefore, in consideration of the eutectic temperature of silver and copper, it is important that the firing can be performed at a low temperature (for example, 780 ° C. or lower), and further, in a reducing atmosphere or a neutral atmosphere to prevent the oxidation of copper. Is.

After that, if necessary, the thick film resistance film 6 and the protective film are baked to mount various electronic components 7.

In the above embodiment, the surface wiring conductor 4 on the lower surface side of the laminated body 1 was formed after the firing step. For example, on the support substrate 15, prior to the laminated body forming step,
It is also possible to form the conductive paste into a predetermined shape, then form the laminated body, and perform the firing treatment integrally with the firing of the laminated body.

Further, although the dividing grooves are formed before the laminated body 1 is peeled from the supporting substrate 15 in the above manufacturing process, it is important to form the dividing grooves before firing, and after the supporting substrate 15 is peeled. It may be formed on both main surface sides of the laminate. Further, regarding the dividing process performed along the dividing groove, the above-described manufacturing process is performed at the end of the surface treatment process, but the dividing process may be performed before mounting the electronic component 7.

As described above, according to the above manufacturing method,
On the supporting substrate 15 having the substrate smoothing layer 16, a ceramic slip material having a photocurable monomer, which is the first step, is applied or printed, and a coating film is formed by a drying process,
After that, selective exposure processing and development processing in the second step are performed.

Here, in the drying process, 87 to 92 wt% of the solvent initially contained in the ceramic slip material is removed, and the stable through-hole forming the via-hole conductor 3 is formed in the developing process in the second step. 30 can be formed.

This improves the connection reliability between the internal wiring conductor 2 and the surface wiring conductor 5, in particular.

[0084]

EXAMPLES The present inventors investigated the solvent removal rate of the coating film and the developability by the development treatment.

First, the thickness of the coating film of the ceramic strip material is 100 μm and 150 μm, the drying temperature is 60 ° C. and 80 ° C., the drying time is controlled, and the solvent removal rate of the ceramic strip material is measured. The developing property by the development processing was evaluated. The evaluation was conducted by evaluating whether or not the through hole to be the via-hole conductor 3 was completely removed.
2 of the film loss that evaluated whether it was developed in the part other than the through hole
The point was evaluated.

The removal rate with respect to the total amount of the solvent is the total weight X before printing or applying the ceramic slip material (for example, only the supporting substrate), and the total weight when the ceramic slip material is printed or applied (before the drying treatment). (X + ΔX), when forming the ceramic slip material, it can be calculated by measuring the ratio a% of the weight of the solvent to the total solid components including the binder, and the total weight after drying (X + ΔX−Δy).

First, the weight of the coating film before the drying treatment is Δx
And the weight y of the solvent contained in the coating film in this state is
Assuming that the weight obtained by y = Δx × a and reduced by the drying treatment is all solvent, the weight of the dried solvent is Δy. Then, the solvent removal rate is calculated by Δy / y × 100.

Table 1 shows the results.

[0089]

[Table 1]

Sample Nos. 1 to 4 in Table 1 are coated films of 100 μm.
m, the drying time was changed at a drying temperature of 80 ° C, and the solvent removal rate was 80% depending on the drying time.
(Sample No. 1), 92% (Sample No. 2), 95% (Sample No. 3), 98% (Sample No. 4).

In each of these states, when selective exposure and development treatments were carried out, in Sample No. 1 having a solvent removal rate of 80%, a slight film reduction phenomenon was caused even in the exposed portion, which was developed. Will end up.

This is because as much as 20% of the solvent remains in the coating film, and when the through hole is formed, it is dissolved in portions other than the predetermined formation position.

In Sample No. 4 having a solvent removal rate of 98%, sufficient penetrability cannot be obtained.

This is because overdrying causes the coating film after drying to become too dense, which makes it difficult for the developing solution to permeate.

On the other hand, in the removal rate of 85 to 97%, for example, in sample numbers 2 and 3, there is no film reduction phenomenon, and
A highly accurate and stable through hole can be formed.

Sample Nos. 1 to 4 had a solvent removal rate of 92%.
In the case of (Sample No. 2), a very excellent through hole is formed, and the same solvent removal rate as 92% is set in Sample No. 5 at a drying temperature of 60 ° C. Although the sample No. 5 required a drying time of 20 minutes, the evaluation was exactly the same as that of the sample No. 2. That is, what is important is the solvent removal rate of the coating film, in other words, the residual rate of the solvent after the drying treatment, and there is no particular problem as long as the drying temperature is such that cracks do not occur on the surface.

Sample Nos. 6 to 9 were prepared by setting the coating film to 150 μm and changing the drying time at a drying temperature of 80 ° C. The solvent removal rates were 78% (Sample No. 6) and 85%, respectively, depending on the drying time. (Sample No. 7), 97% (Sample No. 8), 99% (Sample No. 9).

As can be understood from Samples 7 to 8, even when the thickness of the coating film was 150 μm, the drying time was controlled and
By setting the solvent removal rate to 85 to 97% (85% for sample No. 7 and 97% for sample No. 7), a film reduction phenomenon does not occur and a stable through hole with good penetrability is formed. Things will come.

That is, even if there is a change in the film thickness, it is important to set an appropriate drying time according to the film thickness so that the solvent removal rate is 85 to 97%.

As described above, in the present invention, the via-hole conductor 3 connected to the internal wiring conductor 2 and the surface wiring conductor 4 is selectively exposed to the ceramic coating film and developed by using the ceramic slip material containing the photocurable monomer. In the method for manufacturing a laminated ceramic circuit board formed by filling a conductive paste into a through hole formed by a treatment, the solvent removal rate of the coating film by the drying treatment of the ceramic slip material is 85 to 97 w.
By setting t%, it is possible to easily form a highly accurate and stable through hole, and thereby the connection reliability with the internal wiring conductor 2 and the surface wiring conductor 4 is dramatically improved.

[0101]

As described above, according to the present invention, a ceramic slip material containing a photocurable monomer is applied or printed on a supporting substrate, and a drying process is performed to remove the solvent of the coating film before drying. , 85-97 wt%, the subsequent exposure / development treatment of this ceramic coating film does not cause development of the exposed portion, which enables stable development treatment and becomes a ceramic layer. The diameter, shape, and position of the via-hole conductor that penetrates the coating film can be formed accurately and stably. This improves the connection reliability between the internal wiring conductor and the surface wiring conductor.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a multilayer ceramic circuit board according to the present invention.

2 (a) to 2 (f) are cross-sectional views in the main steps of manufacturing the laminated ceramic circuit board of the present invention.

[Explanation of symbols]

 10 ... Multilayer ceramic circuit board 1 ... Multilayer body 1a to 1e ... Ceramic layer 10a to 10e ... Coating film 2 ... Internal wiring conductor 20 ...・ ・ ・ ・ ・ Conductor film that becomes the internal wiring conductor ・ ・ ・ ・ ・ ・ ・ ・ Via hole conductor 30 ・ ・ ・ ・ ・ ・ Through hole 31 ・ ・ ・・ Surface wiring conductor 15 ・ ・ ・ ・ ・ ・ Supporting substrate 16 ・ ・ ・ ・ ・ ・ Substrate smoothing layer

Claims (1)

[Claims] 1. A coating film to be a ceramic layer is formed on a supporting substrate by coating or printing / drying a ceramic slip material comprising a ceramic filler, a glass frit, a photocurable monomer, an organic binder and a solvent. A second step of forming a through hole in the coating film by a selective exposure process / development process; forming a conductor to be a via-hole conductor in the through hole by printing and filling a conductive paste; A third step of forming a conductor film to be an internal wiring conductor on the top by printing and drying a conductive paste, and forming a laminated body by repeating the first step to the third step and forming it on the support substrate. In the method for manufacturing a laminated ceramic circuit board formed by firing the laminated body, the coating film to be the ceramic layer is dried. Method of manufacturing a multilayer ceramic circuit board, characterized in that 85～97Wt% of the total solvent La mix lip material is removed.