JPH0818237A - Method for manufacturing laminated ceramic circuit board - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a method for manufacturing a laminated ceramic circuit board, which is not affected by surface irregularities of a supporting substrate, has a uniform thickness of a laminated body, and can form surface wiring with high accuracy. According to the present invention, a step of forming a substrate smoothing layer 16 formed on a supporting substrate 15 by coating or printing / drying a slipping material containing an organic binder, and a ceramic slipping material on the substrate smoothing layer 16. Of the coating films 10a to 10e by coating or printing / drying the conductive paste and the conductive film 20 to be the internal wiring pattern 2 by printing / drying the conductive paste in order to obtain a laminate, and the support substrate 15 A method for manufacturing a monolithic ceramic circuit board, comprising a step of, after peeling off a laminated body including a substrate smoothing layer 16 from above, baking 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 forms a laminate in which a coating film serving as a ceramic layer and a conductor film serving as an internal wiring pattern are alternately laminated on a support substrate, and the laminate is peeled from the support substrate. The present invention relates to a method for manufacturing a laminated ceramic circuit board which is then fired.

[0002]

2. Description of the Related Art As described above, a supporting substrate, for example, a ceramic or resin film is used to
There are the following two methods as a method of manufacturing a laminate in which a coating film that is a ceramic layer formed of a ceramic slip material and a conductor film that is an internal wiring pattern formed of a conductive paste are alternately laminated. .

One is a printing multilayer method. This method
A coating film to be a ceramic layer, an internal wiring pattern, and a conductor film to be a via-hole conductor are sequentially laminated and printed on a supporting substrate. Specifically, a coating film to be the lowermost ceramic layer is formed by screen printing and drying a ceramic slip material, and then a conductor film to be an internal wiring pattern is formed on the coating film by using a conductive paste. It is formed by selective printing and drying, and then the coating film to be the ceramic layer is selectively screen-printed on the ceramic slip material so that a part of the conductive film is exposed and a via hole conductor junction is formed. After being formed by drying, a conductive film to be the internal wiring pattern and the via-hole conductor is formed by selective screen printing and drying of a conductive paste, and this process is repeated to form an unbaked laminate. It was After that, the laminate was peeled from the support substrate, the laminate was baked, and surface wiring was formed on the main surface of the baked laminate by baking a conductive paste.

Another manufacturing method is a coating multi-layer method using photocuring. Specifically, the coating film is formed by applying a ceramic slip material containing a photo-curable monomer by a doctor blade method or the like, followed by a drying treatment, and subsequently, a portion other than a portion to be a via-hole conductor penetrating the coating film is photo-cured. Selective exposure process as described above, and a portion to be a via-hole conductor is removed by a development process.

The internal wiring pattern and the conductor film serving as the via-hole conductor are selectively printed with a conductive paste by screen printing or the like, and then dried to fill the removed portion with the conductive paste and to form a via-hole conductor in the coating film. A conductor film to be a wiring pattern including is formed.

These steps are sequentially repeated to form an unfired laminate on the supporting substrate, the laminate is separated from the supporting substrate, the laminate is subjected to a firing treatment, and the main surface of the fired laminate is subjected. The surface wiring was formed by baking a conductive paste.

Particularly in the latter case, the surface of the coating film to be the ceramic layer can be always a flat surface, the conductor film can be accurately formed on the surface, and the positioning and shape of the via-hole conductor are exposed. It is determined only by the control of the position of the photo target in the development process and the shape of the photo target, and the via hole conductor can be formed with an arbitrary shape, for example, a diameter in consideration of the conductor resistance, with high reliability and without misalignment.

[0008]

According to any of the methods, the surface of the laminate peeled from the supporting substrate and in contact with the supporting substrate does not become a flat surface due to the unevenness of the surface of the supporting substrate. There was a problem. For example, when a glass substrate is used as the support substrate, irregularities of several μm to several tens of μm occur. Therefore, it becomes difficult to form the surface wiring on the surface with high accuracy.

If the supporting substrate is not completely parallel to the screen surface (squeegee surface) for printing the ceramic slip material or the blade surface for coating, the thickness of the coating film in contact with the supporting substrate becomes non-uniform. , This allows
The overall thickness of the laminated body also becomes non-uniform, and, for example, variations in shrinkage rate during firing occur.

In particular, in the case of manufacturing by the latter method,
Since the thickness of the coating film that is in contact with the supporting substrate is non-uniform, conditions are changed when the coating film is exposed and developed. Further, there is a problem that the surface roughness of the supporting substrate causes diffuse reflection of the exposure light of the coating film, which makes it difficult to achieve a via-hole conductor having a predetermined shape.

The present invention has been devised in view of the above-mentioned problems, and an object thereof is to provide a laminated body having a uniform thickness even when a laminated ceramic circuit board is manufactured on a supporting substrate, and to provide surface wiring. The present invention provides a method for manufacturing a laminated ceramic circuit board that can be accurately formed.

Another object of the present invention is to apply a ceramic slip material containing a photo-curable monomer to a coating film, dry it, and subject it to selective exposure treatment and development treatment to obtain the accuracy of the shape of the via-hole conductor. A method of manufacturing a monolithic ceramic circuit board having high cost is provided.

[0013]

According to the present invention, there is provided a method for manufacturing a laminated ceramic circuit board, which comprises forming a predetermined wiring pattern including via-hole conductors on a laminated body formed by laminating a plurality of ceramic layers. On the supporting substrate on which the substrate smoothing layer has been formed by applying and drying the slip material, the coating film that becomes the ceramic layer by applying or printing and drying the ceramic slip material, and the via hole by printing and drying the conductive paste. A conductor film serving as a wiring pattern including a conductor is sequentially laminated to form a laminated body, and the laminated body including the substrate smoothing layer is peeled from the supporting substrate, and then the laminated body is fired and the substrate smoothing layer is burned down. This is a method for manufacturing a laminated ceramic circuit board.

Further, preferably, the slip material and the ceramic slip material for forming the substrate smoothing layer contain a photo-curable monomer, and after applying the slip material for the substrate smoothing layer, the entire surface of the coating film is exposed to light. Then, after applying the ceramic slip material, in order to remove a portion which becomes a via-hole conductor that penetrates the thickness of the coating film, a selective exposure treatment / development treatment is carried out to produce a laminated ceramic circuit board.

[0015]

According to the present invention, since a laminate is formed on a supporting substrate on which a substrate smoothing layer made of an organic component is formed, even if unevenness exists on the surface of the supporting substrate, the substrate smoothing is achieved. The layers can absorb the irregularities and form a laminate on a substantially flat surface. Therefore, the main surface of the obtained laminated body becomes flat, and the surface wiring can be accurately formed on this surface.

Even if the surface of the supporting substrate is not parallel to the screen (squeegee) surface or the blade surface, by forming this substrate smoothing layer, it is completely parallel to the screen (squeegee) surface or the blade surface. As a result, the thickness of the laminate can be made uniform.

When the laminate is peeled from the supporting substrate,
Even when the substrate smoothing layer is attached to the laminate side, when the laminate is fired, the substrate smoothing layer made of an organic component is completely burned down, so the surface treatment of the fired laminate is performed. For example, even when the surface smoothing is formed, the fact that the substrate smoothing layer is used in the manufacturing process has no effect.

Further, a slip material for forming a substrate smooth layer and a ceramic slip material for a coating film are coated with a slip material for a substrate smooth layer after containing a photo-curable monomer, and then the coating film. The whole surface is exposed to light, the ceramic slip material to be the ceramic layer is applied and dried,
By performing selective exposure / development processing, each exposure processing condition becomes substantially the same, stable exposure processing is possible, and the diameter, shape, position, etc. of the via-hole conductor that penetrates the coating film to be the ceramic layer are accurate. It can be formed well and stably.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a laminated ceramic circuit board according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a laminated ceramic circuit board according to the present 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 an internal wiring pattern for forming a predetermined circuit therein, and a surface wiring pattern formed on the surface of the laminated body 1. 4, 5, a thick film resistor film 6 connected to the surface wiring patterns 4, 5 as necessary, various electronic components 7, and the like.

The laminated body 1 comprises ceramic layers 1a to 1e,
An internal wiring pattern 2 for achieving a predetermined circuit network and generating a capacitive component is provided between the ceramic layers 1a to 1e.
Is arranged. 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. Further, at least one crystal of cordierite, mullite, anorthite, sergian, spinel, garnite, willemite, dolomite, petalite or a substituted derivative thereof is obtained by firing a glass frit containing a plurality of metal oxides as a glass material. Is deposited. The thickness of the ceramic layers 1a to 1e is, for example, about 10 to 100 μm.

Internal wiring pattern 2, via-hole conductor 3
Is Ag-based (Ag simple substance, Ag alloy such as Ag-Pd),
The internal wiring pattern 2 has a thickness of about 8 to 15 μm, and the diameter of the via-hole conductor 3 can be set to an arbitrary value.
For example, the diameter is 80 to 250 μm.

Surface wiring patterns 4 and 5 are formed on both main surfaces of the laminate 1. The surface wiring pattern 4 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 pattern 5 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 patterns 4 and 5 are Ag-based (Ag alone,
Ag alloys such as Ag-Pd), Cu-based (Cu simple substance, Cu
Alloy) and other conductors. The surface wiring pattern 5 is
It is desirable to use the same material as the internal wiring pattern 2.

Further, the surface wiring patterns 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. Further, in the case where the laminate 1 is fired at the same time as firing (for example,
The surface wiring pattern on the lower surface side of the laminated body 1 is set to be fired under the firing conditions of the internal wiring pattern 2.

The surface wiring patterns 4 and 5 include input / output terminal portions and electronic component mounting pads, and although not shown in the drawing, the thick film resistor film 6 and the insulation protection are provided as necessary. A film is formed.

A thick film resistor film 6 is formed on the surface wiring patterns 4 and 5 of such a laminated body 1, and various electronic parts 7 such as chip capacitors, chip resistors, transistors and ICs are soldered. It is mounted by wire bonding.

A method of manufacturing the above-mentioned laminated ceramic circuit board will be described with reference to the process chart of FIG. 2 and the sectional views in the main steps of FIGS. 3 (a) to 3 (j). The manufacturing method will be described using a coating multilayer method using a ceramic slip material having a photocurable monomer.

The method for manufacturing the laminated ceramic circuit board 1 is as follows.
It is roughly divided into a preparatory step (step (a) in FIG. 2), a stacking step (steps (b) to (h) in FIG. 2), and a peeling step (step (i) in FIG. 2). ), Firing treatment step (step (j) in FIG. 2), surface treatment step ((k) in FIG. 2)
Process) and.

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 pattern 2, the via-hole conductor 3, and the conductive film or the conductive paste of the conductor to be the surface wiring pattern 5 are formed. It is a process of preparing each.

[Supporting Substrate] As shown in FIG. 3 (a), the supporting substrate 15 is made of a substrate such as ceramic, glass, or heat resistant resin. 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, and a solvent to form a coating film, and then exposing and curing the entire surface of the coating film. Formed by. Substrate smoothing layer 16
Is at least thick enough to absorb the irregularities of the support 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 process, 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 and in a short-time firing 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.

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 photoinitiator material and the like 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.

Since the exposure treatment is a negative type in which the photo-curable monomer contained in the coating film is photopolymerized, the entire surface of the coating film is exposed to 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.

[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. The ceramic materials may be used as a mixture of two or more kinds. 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 pattern 2 is similar. The average particle size of the glass frit is 1.0 to 6.0 μm, preferably 1.5 to 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 together 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 amount of addition is 2 to 300, preferably 5 to 100, expressed 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 are poor, and when the addition amount is large, the thermal decomposability is poor. Therefore, the addition amount is the solubility and dispersibility in water, Considering the thermal decomposability, it is appropriately added within the above range.

If desired, a sensitizer, a photoinitiator material, etc. may be added to the slip material. 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, the surface wiring pattern 5
Also, this paste may be used. Incidentally, in the conductive paste for the conductor film which becomes the internal wiring pattern 2,
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.

[Laminating Step] In this way, the supporting substrate 1
After the substrate smoothing layer 16 is formed on the substrate 5, the ceramic slip material and the conductive paste are prepared, a substantial stacking process is performed. Although the support substrate 15 simultaneously forms regions of a plurality of laminated bodies so that a plurality of laminated bodies can be finally extracted,
Here, a region of one stacked body will be described.

First, as a step of stacking step of FIG. 2B, as shown in FIG. 3B, the surface wiring pattern on the lower surface side of the stack 1 is formed on the substrate smoothing layer 16 of the supporting substrate 15. A conductor film 50 to be 5 is formed. Specifically, the conductor film 50 having a predetermined shape is formed by screen printing of the above-described conductive paste in the region of the support substrate 15 that will be each laminated body. Then, if necessary, the entire surface is exposed to light and cured.

Next, as a step of FIG.
As shown in (c), a ceramic coating film 10e to be the ceramic layer 1e is formed. The coating film 10e of the ceramic slip material is formed over the entire surface of the substrate smoothing layer 16 of the supporting substrate 15 so as to cover the conductor film 50 formed on the substrate smoothing layer 16 and beyond each region. Specifically, the above-mentioned ceramic slip material is applied by a doctor blade method or the like,
Drying (120 ° C in batch type drying furnace, in-line type drying furnace)
Do the following).

Next, as a step of FIG.
As shown in (d), the ceramic coating film 10e is selectively exposed and developed to form the through recesses 30.

In the exposure process, since the through recess 30 is formed at a position which becomes the via hole conductor 3 penetrating the thickness of the ceramic layer 1e, a photo target having a predetermined pattern so that the exposure light is not irradiated only on this portion is coated with a coating film. 10
Exposure conditions when the substrate smoothing layer 16 is formed by being placed close to or on the substrate e (15 to 2 of low-pressure, high-pressure, and ultra-high-pressure mercury lamp system).
Exposure light of 0 mW / cm ² is irradiated for about 5 to 30 seconds)
Process.

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.

The shape, diameter and the like of the through hole 30 which becomes the via-hole conductor 3 can be arbitrarily set by controlling the shape of the photo target by the above-mentioned selective exposure processing and development processing. 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 fine surface processing of a semiconductor chip or the like, there is no displacement in the penetrating recess 30 of the via hole conductor 3 formed under the control of the photo target, and the conduction reliability of the via hole conductor 3 is high. Greatly improved.

Next, as a step of FIG.
As shown in (e), the through-hole recess 30 formed in the coating film 10e is filled with the conductor 31 serving as the via-hole conductor 3, and the ceramic layer 1e is formed on the ceramic coating film 10e.
Then, the conductor film 20 to be the internal wiring pattern 2 between the ceramic layer 1d and the ceramic layer 1d is formed.

Specifically, the above-mentioned conductive paste is printed in a predetermined shape by screen printing to obtain the coating film 1
The conductor 31 serving as the via-hole conductor 3 is filled in the through recess 30 of 0e. At the same time as this printing, the coating film 10
A conductor film 20 to be the internal wiring pattern 2 having a predetermined pattern is formed on the substrate e. After that, a drying process is performed, an exposure process is performed, and photocuring is performed.

When the shape of the through recess 30 is large, first, the conductor 31 is filled in the through recess 30 with a conductive paste using a dispenser or the like, and then the conductor film 20 to be the internal wiring pattern 2 is formed. It may be formed by printing.

Next, by repeating the step of FIG. 2C,
As shown in FIG. 3F, a coating film 10d that will be the ceramic layer 1d is formed on the coating film 10e that will be the ceramic layer 1e. Specifically, the above ceramic slip material is applied so as to cover the conductor 31 serving as the via-hole conductor 3 formed on the ceramic coating film 10e and the conductor film 20 serving as the internal wiring pattern 2 formed on the ceramic coating film 10e. Apply by doctor blade method etc. and dry.

As a result, the coating surface of the ceramic coating film 1d is uniform regardless of the shape and the laminated state of the conductor 31 which becomes the via-hole conductor 3 covered by the coating film 1d and the conductor film 20 which becomes the internal wiring pattern 2. It can be a flat surface.

Next, the step of FIG. 2D and the step of FIG.
Is applied to the coating film 10d to form a penetrating recess which becomes the via-hole conductor 3 in the coating film 1d, and a conductor 31 which becomes the via-hole conductor 3 is filled and formed in the penetrating recess, and at the same time the internal wiring pattern 2 is formed. The conductor film 20 is formed. Further, the process of FIG. 2C to the process of FIG. 2E is repeated depending on the laminated structure of the laminated body 1. In this way, the conductor film 20 to be the internal wiring pattern 2 between the ceramic layers 1b and 1a is formed.

Next, in the step of FIG. 2F, the ceramic layer 1a is formed on the coating film 10b to be the ceramic layer 1b.
A coating film 10a that becomes In addition, this process is shown in FIG.
The process is substantially the same as that of (c).

Next, in the step of FIG. 2G, the via-hole conductor 3 is formed on the coating film 10a to be the ceramic layer 1a.
To form a through recess. Note that this step is substantially the same as the step shown in FIG.

Next, as a step of FIG.
As shown in (g), the conductor 31 serving as the via-hole conductor 3 is filled in the through recess formed in the ceramic coating film 10a. In this step, the conductive paste is printed on the through recesses or the conductive paste is supplied by a dispenser and dried.

Since the laminating step of the laminated body 1 is completed, the photo-curing of the conductor 31 which becomes the via-hole conductor 3 by the exposure process can be omitted.

After the stacking process is completed, each stack 1
It is desirable to form the dividing groove by press molding or the like according to the shape of the above.

[Peeling Step] Next, as a step of FIG. 2I, as shown in FIG. 3H, the supporting substrate 15 to the substrate smoothing layer 16 and the conductor film 50 to be the surface wiring pattern 5 are included. Ceramic coating films 10a to 10e, conductor film 20 to be internal wiring pattern 2, conductor 31 to be via-hole conductor 3
The unfired laminated body consisting of is peeled off.

As described above, the peeling interface is the interface between the supporting substrate 15 and the substrate smoothing layer 16, and the substrate smoothing layer 1 is provided on the laminate side.
6 is left. Therefore, even if the peeling is mechanically performed, for example, the support substrate 15 is curved, and the cutter blade is slid on the peeling interface in a planar manner, the laminate itself is not adversely affected (cracking due to peeling) and is stable. Can be peeled off.

In addition, at the interface between the supporting substrate 15 and the substrate smoothing layer 16, a resin layer which causes a foaming reaction at 120 ° C. (drying temperature) or higher is provided, or in the substrate smoothing layer 16. , A member that causes a foaming reaction is mixed, and heat treatment is performed at 120 ° C or higher to facilitate peeling,
In addition, a sheet that dissolves in an organic solvent is interposed at the interface between the support substrate 15 and the substrate smoothing layer 16, or a sheet that dissolves the support substrate 15 itself in an organic solvent is used, and peeling is performed by immersion in the organic solvent. You may do so. 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, in the step of FIG. 2 (j), as shown in FIG. 3 (i), the substrate smoothing layer 16 separated from the supporting substrate 15 and the conductor film 50 to be the surface wiring pattern 5 are formed. The unbaked laminated body containing is fired. 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 serving as the internal wiring pattern 2, the conductor 31 serving as the via-hole conductor 3, the organic component contained in the conductor film 50 serving as the surface wiring pattern 5, and the substrate smoothing layer 1
6 is burned out, and is performed in a temperature range of 600 ° C. or less, for example.

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 conductor film 20 that becomes the internal wiring pattern 2, the conductor 31 that becomes the via-hole conductor 3, and the conductor film 5 that becomes the surface wiring pattern 5.
A conductive material of No. 0, for example, a silver-based powder is grain-grown to reduce the resistance and is integrated with the ceramic layers 1a to 1e. This is the peak temperature of 850-105
It is performed until reaching 0 ° C.

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 the 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 pattern 2, the conductor 31 becomes the via-hole conductor 3 and the conductor film 50 becomes the surface wiring pattern 5, and the baked large size It becomes a laminated substrate.

[Surface Treatment Step] Next, as a step of FIG. 2 (k), as shown in FIG. 3 (h), surface treatment is performed on both main surfaces of the fired large-sized laminate substrate.

For example, the surface wiring pattern 4 is formed by printing, drying, and baking a copper-based conductive paste, for example, so as to connect to the via-hole conductor 3 formed in the ceramic layer 1a on the main surface on the upper surface side of the large-sized laminate substrate. To form.
Here, the copper-based surface wiring pattern 4 and the via-hole conductor 3 of a silver-based conductor are joined. Therefore, considering the eutectic temperature of silver and copper, low temperature (eg 780 ° C or lower)
It is important to carry out in a reducing atmosphere or a neutral atmosphere in order to be calcinable and to prevent the oxidation of copper.

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

Here, the surface wiring pattern 5 on the back surface side is
It is formed in the laminating process of the laminated body 1, and its surface is flush with the surface of the laminated body 1. Therefore, for example, the thick film resistor film 6
In forming the film, a step is not formed at the end of the thick film resistor film 6, and the step of the resistor film 6 does not occur. Also, when mounting an electronic component 7 such as an IC chip, since the bonding surface of the electronic component is the surface of the laminated body 1 and the surface wiring pattern 5, especially in the case of a surface mount type electronic component or a flip chip type IC chip. It is suitable for mounting and joining.

Then, the large-sized laminated substrate is divided into laminated bodies having a predetermined shape along the dividing grooves formed before firing. As a result, the laminated ceramic circuit board having the structure shown in FIG. 1 is completed.

Although the surface wiring pattern 5 on the lower surface side of the laminated body 1 was formed in a part of the laminating step in the above-described embodiment, the surface wiring pattern 4 on the upper surface side of the laminated body 1 is
It can also be formed by a surface treatment step performed on the fired laminate. Alternatively, conversely, the surface wiring pattern 4 on the upper surface side may be formed in the final step of the stacking step and may be performed integrally with the firing of the stack.

Further, although the dividing grooves are formed in the above-described manufacturing process before peeling the laminated body 1 from the supporting substrate 15, it is important to form the dividing grooves before firing, and after peeling the supporting substrate 15. 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,
As a pre-lamination treatment step, a substrate smoothing layer 16 is formed on the supporting substrate 15 by applying a slip material containing an organic binder that is burned down in the firing step, and then a laminate (ceramic layer 1a) is formed on the substrate smoothing layer 16. Coating films 10a to 10e having a thickness of ˜1 g and a conductor film 2 serving as an internal wiring pattern 2
0, and a conductor film 31 to be the via-hole conductor 3 are laminated to form an unfired laminated substrate). Therefore, the unevenness of the surface of the support substrate 15 is absorbed by the substrate smoothing layer 16, and a uniform flat surface can be formed without affecting the main surface on the lower surface side of the laminate 1. That is, in performing the surface treatment on the main surface on the lower surface side of the laminated body 1, the thick film resistor film 6 is formed,
The electronic component 7 can be mounted stably and with high reliability.

Further, since the substrate smoothing layer 16 is formed by the doctor blade method of the slip material, the substrate smoothing layer 16
Since the surface of the laminated body is parallel to the drape surface of the doctor blade method of the ceramic slip material thereafter, the laminated body 1
Does not vary in thickness. This stabilizes the sintering shrinkage rate during firing.

Further, since the substrate smoothing layer 16 is formed between the actual supporting substrate 15 and the laminated body 1, when the coating film 10e to be the ceramic layer 1e is formed and the exposure processing is performed, the exposure light is exposed. Does not diffusely reflect on the uneven surface of the support substrate 15, so that highly accurate exposure processing is achieved,
The through recess 30 that becomes the stable via-hole conductor 3 is formed.

Further, in the above-described manufacturing method, the coating surface of the ceramic coating films 10a to 10e is always flat regardless of the internal wiring pattern 2 on the lower side and the laminated shape. Therefore, the conductor film 20 to be the internal wiring pattern 2 can be accurately formed on the coated surface. Also, regarding the surface wiring pattern 4, since the surface on the upper side of the laminated body 1 becomes flat, when forming the surface wiring pattern 4,
It can be stably formed.

Further, since the conductor 31 to be the via-hole conductor 3 is formed by filling the through recess 30 formed by the selective exposure process / development process with the conductive paste, the shape and diameter of the via-hole conductor 3 can be controlled. Becomes extremely easy,
Moreover, since the formation position of the via-hole conductor 3 can be controlled accurately, the connection reliability is improved.

Since the ceramic coating film is formed on the entire surface by the doctor drading method, it becomes easy to control the thickness of the ceramic coating film.

In the above manufacturing method, the conductive paste also contains a photocurable monomer. Therefore, in forming the internal wiring pattern 2, a conductive film may be formed on the entire surface, and then selective exposure processing and development processing may be performed according to the shape of the internal wiring pattern 2. In addition, during the development process after the coating film of the ceramic slip material is formed, the conductive paste or the developing solution is controlled so that the conductive film 20 which becomes the internal wiring pattern 2 exposed from the lower opening of the through recess 30 is not attacked by the developing solution. , It is not necessary to include a photocurable monomer in the conductive paste,
Also, the exposure process can be omitted.

In the laminating step described above, the ceramic slip material containing the photocurable monomer is replaced with the ceramic slip material containing no photocurable monomer (ceramic paste), and the ceramic paste is selectively shaped. That is, you may form by screen printing so that the part used as a via-hole conductor may be exposed. In this case, the photo-curable monomer can be omitted also in the conductive paste for forming the conductor film to be the internal wiring pattern 2, and the exposure process and the development process can be omitted in both cases.

[0095]

As described above, according to the present invention, in order to form a laminated body on a supporting substrate having a substrate smoothing layer formed on the surface thereof, the surface of the laminated body, that is, the main surface on the supporting substrate side is supported. A flat surface can be obtained without being affected by the unevenness of the surface of the substrate.

Therefore, the surface wiring pattern or the thick film resistor film can be formed on this surface, or the electronic device can be mounted stably.

Further, in particular, even if the supporting substrate is slightly inclined, it can be corrected by the substrate smoothing layer and can be made completely parallel to the screen (squeegee) surface and the blade surface, and the thickness of the coating film can be improved. In addition, the thickness of the laminate can be made uniform, and the shrinkage rate during firing is stable.

When the laminate is peeled from the supporting substrate,
Even when the substrate smoothing layer is adhered to the side of the laminate, the organic binder component is not completely burned out when the laminate is fired, and thus the surface treatment of the fired laminate, for example, the surface The use of the substrate smoothing layer in the manufacturing process does not affect the formation of wiring or the like.

Further, a photo-curable monomer is contained in a slip material for forming a substrate smoothing layer or a ceramic slip material serving as a coating film, the slip material serving as a substrate smoothing layer is applied, and then the coating film is formed. The whole surface is exposed to light, the ceramic slip material to be the ceramic layer is applied and dried,
By performing selective exposure / development processing, each exposure processing condition becomes substantially the same, stable exposure processing is possible, and the diameter, shape, position, etc. of the via-hole conductor that penetrates the coating film to be the ceramic layer are accurate. It can be formed well and stably.

[Brief description of drawings]

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

FIG. 2 is a process drawing for explaining the manufacture of the laminated ceramic circuit board of the present invention.

3 (a) to 3 (j) 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 pattern 20 ...・ ・ ・ Conductor film that will become internal wiring pattern ・ ・ ・ ・ ・ ・ ・ ・ Via hole conductor 30 ・ ・ ・ ・ ・ ・ Through hole 31 ・ ・ ・ ・ conductor that becomes via hole conductor 4,5・ Surface wiring pattern 15 ・ ・ ・ ・ ・ ・ Supporting substrate 16 ・ ・ ・ ・ ・ ・ ・ ・ Smoothing substrate

Claims (2)

[Claims] 1. A method for manufacturing a laminated ceramic circuit board, comprising: forming a predetermined wiring pattern including a via-hole conductor on a laminated body formed by laminating a plurality of ceramic layers; applying and drying a slip material made of an organic component. Conductor that becomes a wiring pattern including a via-hole conductor by coating and printing / drying a ceramic slip material, and a coating film that becomes a ceramic layer on a supporting substrate on which a substrate smoothing layer has been formed by processing. A laminated ceramic characterized in that a film and a film are sequentially laminated to form a laminated body, the laminated body including the substrate smoothing layer is peeled off from the supporting substrate, and then the laminated body is fired and the substrate smoothing layer is burned off at the same time. Circuit board manufacturing method. 2. The slip material and the ceramic slip material for forming the substrate smoothing layer contain a photo-curable monomer, and after applying the slip material for the substrate smoothing layer, the coating film is subjected to the entire surface exposure treatment to obtain a ceramic. 2. The multilayer ceramic circuit board according to claim 1, wherein after the slip material is applied, a selective exposure treatment / development treatment is performed in order to remove a portion which becomes a via-hole conductor penetrating the thickness of the coating film. Production method.