JP2003198130A - Method of manufacturing ceramic multilayer substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a ceramic multilayer substrate which has assured good yield and improved reliability. <P>SOLUTION: In this method of manufacturing the ceramic multilayer substrate, a conductor pattern 1 is formed, with an intaglio printing method, on a ceramic substrate 2 and an insulated layer 21 is formed at least on the conductor pattern 1. Particularly, a process to remove residues at the surface of the intaglio after filling of conductive paste and a process for chemical wet etching of the baked conductor pattern and subsequent cleaning step are added to this method. <P>COPYRIGHT: (C)2003,JPO

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 ceramic multilayer substrate for mounting electronic parts.

[0002]

2. Description of the Related Art In recent years, electronic devices have been downsized,
As a result, there is no end to the miniaturization of electronic components used in electronic devices. The same applies to a ceramic multilayer substrate on which electronic components are mounted, and there is a trend toward realizing higher density wiring by miniaturization technology of conductors and via holes forming circuits or multilayer technology.

As this prior art, Japanese Patent Laid-Open No. 11-1216
Japanese Unexamined Patent Publication No. 45-45 discloses a method for manufacturing a ceramic multilayer substrate by the intaglio transfer method. The conventional method for manufacturing a ceramic multilayer substrate will be described with reference to FIG.

Grooves are formed on the surface of the flexible resin base material in a pattern corresponding to the conductor pattern of the first layer, that is, an intaglio is formed (A), and the grooves are filled with a conductive paste (B) and removed. A step (C) of foaming and drying, a step (D) of forming an adhesive layer on a ceramic substrate, a step (E) of bonding the intaglio plate and the ceramic substrate by applying heat and pressure within a predetermined range, and an intaglio plate. Is separated from the ceramic substrate to transfer the pattern of the conductive paste onto the ceramic substrate (F) and fired (G) to form the conductor pattern of the first layer, and on the conductor pattern of the first layer A step (H) of forming an insulating layer by printing, a step (I) of drying and baking the insulating layer, a step (J) of polishing the insulating layer to expose the via portion, and further a step of Print the second layer conductor pattern on Dense ceramic multilayer substrate is manufactured by a process (K).

[0005]

However, in the above-described conventional manufacturing method, when the conductor pattern width (L) and the conductor pattern interval (S) are further narrowed, specifically, L / S = 20 μm. When narrower than / 20 μm,
It has the following problems. Since the flexible resin base material is made of resin, the narrower the groove spacing of the intaglio plate, the more easily the groove is deformed due to the stress of the squeegee when the paste is filled, and as a result, when the intaglio plate is reused many times. There is a problem that the durability of the intaglio is reduced. As the groove spacing of the intaglio becomes narrower, a slight amount of the conductive paste residue on the surface of the intaglio during paste filling causes a short circuit between conductor patterns or a decrease in insulation between conductor patterns, resulting in a decrease in reliability. Have. As the groove spacing of the intaglio becomes narrower, that is, the conductor pattern spacing becomes narrower, it becomes very difficult to print the insulating paste on the conductor pattern without entraining air bubbles, and as a result, the reliability decreases. Have. The narrower the groove width of the intaglio, that is, the narrower the conductor pattern width, the more uneven the pressure applied to the intaglio and the ceramic substrate in the step of bonding the intaglio and the ceramic substrate, the more easily the ceramic substrate is damaged. Further, there is a problem that the transfer yield of the conductor pattern is deteriorated.

Therefore, an object of the present invention is to provide a method for manufacturing a ceramic multilayer substrate which solves the above problems.

[0007]

In order to achieve this object, the invention according to claim 1 of the present invention is that a first conductor pattern is formed on a ceramic substrate by intaglio printing, and the first conductor pattern is formed on the first conductor pattern. A method for manufacturing a ceramic multilayer substrate, comprising forming an insulating layer, comprising: (a) forming a first groove on a surface of a flexible resin substrate in a pattern corresponding to a first conductor pattern; A step of manufacturing an intaglio in which the second groove is formed deeper than the first groove in a pattern corresponding to the via portion; and (b) filling the first and second grooves with a conductive paste to remove bubbles. A drying step, and (c) a step of refilling with an additional conductive paste to compensate for the volume reduction due to the drying of the conductive paste dried in the step (b), re-defoaming and re-drying. Repeating the number of times, and A step of removing a conductor residue remaining on the surface of the intaglio after filling with paste, (e) a step of attaching the intaglio and the ceramic substrate by applying heat and pressure within a predetermined range, and (f) this intaglio From the ceramic substrate, transferring the pattern of the conductive paste onto the ceramic substrate to form the first conductor pattern, and (g) printing and forming the first insulating layer on at least the first conductor pattern. A step, (h) a step of printing and forming a second conductor pattern on the first insulating layer, (i) a first conductor pattern after the step (f) and a second conductor pattern after the step (h) A method for manufacturing a ceramic multilayer substrate, comprising the steps of chemically wet-etching at least one of the above, and then cleaning it, even if the wiring density is high and the space between the conductor patterns is extremely narrow. Mari is high, it is possible to highly reliable ceramic multilayer substrate.

According to the second aspect of the invention, the wet etching in the step (i) uses nitric acid having a concentration of 25 to 40%,
The method for producing a ceramic multilayer substrate according to claim 1, wherein etching is performed for 5 to 5 minutes. When a general Ag-based material is used as a conductor material, Ag powder scattered between conductor patterns due to diluted nitric acid is generated. Since it is removed as silver nitrate, the insulation between the conductor patterns is increased, and as a result, the reliability of the ceramic multilayer substrate is improved. Note that when the concentration of nitric acid is low, the etching time becomes long, as a result, the productivity is deteriorated, and when the concentration is high, the etching rate becomes high, making it difficult to control the etching state. It will be excessively etched. Therefore, the concentration of nitric acid should be 25 to 40%, and the etching time should be 0.5 to 5 minutes.

According to a third aspect of the invention, in the step (g), a first insulating layer is formed by printing on the entire surface of at least the first conductor pattern, air bubbles are removed from the first insulating layer, and then dried. The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding the dry film of the first insulating layer, and firing.
Insulation defects due to the presence of bubbles not only between the conductor patterns of the same layer but also between the first and second conductor patterns are suppressed, and as a result, the reliability of the ceramic multilayer substrate is improved.

According to a fourth aspect of the present invention, in the step (g), a first insulating layer is formed by printing on the entire surface of at least the first conductor pattern, air bubbles are removed from the first insulating layer, and then dried. The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding the first insulating layer after firing, and the high density is achieved even if the via size and the via pitch are reduced. Since the via can be exposed, the top surface of the via and the surface of the insulating layer are the same and can be flattened. Furthermore, since no bubbles remain between the first insulating layer and the via, excellent insulative properties are achieved. The transfer can be performed with a high yield and the reliability is excellent.

According to a fifth aspect of the present invention, in the step (g), a first insulating layer is printed on the entire surface at least on the first conductor pattern, air bubbles are removed from the first insulating layer, and then dried. The method for producing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding the dry film of the first insulating layer, and after firing, polishing or grinding is performed again. Since the vias can be exposed at a high density, the top surface of the via and the surface of the insulating layer are on the same level, and the flattening process is easy, so it can be manufactured at low cost, and no bubbles remain between the insulating layer and the via. It also has excellent insulating properties and enables intaglio transfer from the second layer onward with a high yield, and also has excellent reliability.

According to a sixth aspect of the present invention, there is provided a method for producing a ceramic multilayer substrate according to the first aspect, in which a dielectric layer is formed by printing on a part of the ceramic substrate, air bubbles are removed from the dielectric layer, and then drying is performed. The formation of the dielectric layer has the effect of reducing power supply noise, and also has the effect of excellent insulation due to the absence of air bubbles between the dielectric layer and the via, high yield, and excellent reliability. .

The invention according to claim 7 is the method for producing a ceramic multilayer substrate according to claim 1, wherein in the step (e), pressure is applied by compressed air between the intaglio and the ceramic substrate and the press. The pressure applied to the ceramic substrate is not directly applied from the press body, but it is applied to the intaglio surface and the ceramic substrate surface with compressed air, so that even if there is unevenness in the thickness of the substrate, the pressure distribution is made uniform and damage to the ceramic substrate This has the effect of significantly reducing transfer defects of the conductor pattern.

The invention according to claim 8 is the method for producing a ceramic multilayer substrate according to claim 1, wherein the flexible resin substrate has an elastic modulus of 500 kg / cm ² or more. Since the base material has a high elastic modulus, even if the groove spacing of the intaglio is narrow, deformation of the grooves due to the stress of the squeegee is unlikely to occur, so the life of the intaglio is greatly extended, and as a result, it is greatly effective in reducing the production cost. At the same time, since the deformation of the groove is small, the conductor residue on the surface of the intaglio plate is small, and the short circuit defect between patterns can be reduced.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a ceramic multilayer substrate according to the present invention will be described below with reference to embodiments and drawings.

(Embodiment 1) The invention described in claims 1, 2, 7 and 8 will be described with reference to the present embodiment 1 and FIGS.

The ceramic multilayer substrate according to the first embodiment is
As shown in FIG. 1, there is a first conductor pattern 3 on a ceramic substrate 2 having a conductor line width of 10 μm, a line interval of 20 μm, and a conductor film thickness of 10 μm after firing. It has a via 11 having a diameter of 50 μm. A first insulating layer 21 is formed on the first conductor pattern 3.
And a second conductor pattern 4 further thereon, and the second conductor pattern 4 is electrically connected to the via 11.

Next, the manufacturing method of the first embodiment will be described in the order of steps. First, the first conductor pattern 3 is manufactured by intaglio transfer printing. In FIG. 2, the intaglio 40 used was a polyimide film, which was a flexible resin substrate having a thickness of 125 μm, as a material. Then, the polyimide film was irradiated with a laser beam having a wavelength of 248 nm in the ultraviolet region using an excimer laser device to form the first groove 12 having a shape corresponding to a desired conductor pattern. That is, since the polyimide irradiated with the laser beam is decomposed by the photochemical reaction, the first groove 12 corresponding to the line of the first conductor pattern 3 is formed in the polyimide film.
In the first embodiment, the width of the groove 12 is 12 μm and the depth of the groove 12 is 16 μm. Next, a second groove 13 having a pattern corresponding to the via 11 of the first conductor pattern 3 was formed in the first groove 12 using the same excimer laser device as described above. The diameter of the deepest part of the second groove 13 is 65 μm, and the groove depth is 90 μm.
And

When an excimer laser is used as the method for forming the grooves 12 and 13 as the flexible resin base material, any material that can be decomposed by a photochemical reaction can be used. In addition to polyimide, polyethylene terephthalate can be used. Also, polyetherimide, aramid, etc. can be used.
Now, as the grooves 12 and 13 of the intaglio 40 become finer patterns, the following problems occur. That is, as shown in FIG. 2, a squeegee 41 is used to fill the grooves 12 and 13 with the conductor paste 42, but the sliding causes abrasion of the surface of the intaglio 40 and deformation of the grooves 12 and 13, and the ceramic The reliability as a multi-layer substrate decreases. However, by using a flexible resin base material having an elastic modulus of 500 kg / cm ² or more, deformation of the grooves 12 and 13 and abrasion of the surface thereof can be significantly reduced.

In the first embodiment, the elastic modulus is 930 kg / c.
m ² polyimide film and elastic modulus 1500 kg / cm ²
The aramid film was used, but the groove was not deformed at all even after 100 times of use. On the other hand, the conventional elastic modulus is 50
In the case of the pattern of the present design, the polyimide film of less than 0 kg / cm ² has a very narrow groove interval of 18 μm, and therefore the groove is deformed and damaged after 20 times of use, so that it cannot be used.

In the first embodiment, the intaglio 4 is intended to enhance the peelability between the conductor film 42 filled in the grooves 12 and 13 and transferred and the polyimide film.
A peeling layer (not shown) was formed on the surface of No. 0, especially on the surfaces of the grooves 12 and 13. A fluorocarbon monolayer was used for the release layer.

Next, an Ag paste is applied as the conductor paste 42 on the surface of the intaglio plate 40 on which the release layer is formed.
Then, the surplus Ag paste on the surface of the intaglio plate 40 is removed by scraping the surface of the intaglio plate 40 after coating with a squeegee 41, and the grooves 12 and 13 are sufficiently filled with the Ag paste.

When the intaglio 40 is filled with the conductive paste 42, the widths of the grooves 12 and 13 are particularly narrowed or the second groove 1 is filled.
As shown in FIG. 3, the bubbles 8 tend to remain as shown in FIG. 3 (a). Therefore, in the first embodiment, the intaglio plate 40 filled with the conductor paste 42 is put in a vacuum device to defoam, and the surface of the intaglio plate 40 is scratched again with the squeegee 41 to eliminate bubbles 8 as shown in FIG. 3B. The conductor paste 42 was filled.

The filled Ag paste is dried together with the intaglio plate 40 using a drier to evaporate the organic solvent in the Ag paste. Therefore, the volume of the Ag paste filled in the grooves 12 and 13 is reduced by the amount corresponding to the evaporation of the organic solvent. Therefore, in order to compensate for this volume reduction, the step of filling the Ag paste and the step of drying are repeated again. By repeating this, the thickness of the Ag paste filled after drying can be made substantially equal to the depth of the grooves 12 and 13. In the first embodiment, filling, defoaming and drying were repeated 3 times.

Next, on the surface of the intaglio plate 40, grooves 12, 13 are formed.
In order to remove the conductor paste residue 9 adhering to the other parts, for example, as shown in FIG.
A micron ultrafine fiber cloth 30 is attached to a wiping squeegee 31 and wiped. Conductor paste residue 9
The particle size of the Ag powder is about 2 μm or less, and the fiber diameter of a normal cloth is about 15 μm, so it is difficult to completely remove the Ag powder. Therefore, when a cloth is used for wiping, the fiber diameter is preferably 2 μm. As a result, as shown in FIG. 3D, the surface of the intaglio plate 40 was cleaned to remove Ag powder that causes a short circuit between the grooves.

On the other hand, in the ceramic substrate 2, as shown in FIG. 4, the through holes 7 were filled with a conductive paste by screen printing, dried and fired. Note that Ag-Pd was used as the conductor paste.

Then, an adhesive layer 4 made of a thermoplastic resin so that the conductor pattern is transferred onto the ceramic substrate 2.
4 was formed on the ceramic substrate 2. As a forming method, a method of applying a mixed solution of toluene, acetone, and alcohol in which a polyvinyl butyral resin (hereinafter abbreviated as PVB), which is a thermoplastic resin, is applied to the surface of the ceramic substrate 2 by a dip method, and then drying is used. I was there. As a result, a P layer having a thickness of 5 μm is formed on the entire surface of the ceramic substrate 2.
The VB layer is formed as the adhesive layer 44. Next, FIG. 5 (a)
As shown in, the surface of the intaglio 40 on which the grooves 12 and 13 are formed and the adhesive layer 44 are opposed to each other, and the intaglio 40 and the ceramic substrate 2 are heated and pressed to bond them together.

The temperature of the bonding step was 150 ° C.
This was a temperature about 30 ° C. higher than the glass transition point of the thermoplastic resin used, that is, PVB, and it was confirmed that the transferability of the conductor pattern at this time was good.

Another bonding method is shown in FIG. 5 (b). In FIG. 5B, the ceramic substrate 2 on which the adhesive layer 44 is formed and the spacer 36 having substantially the same material thickness as the ceramic substrate 2 are provided on the outer peripheral portion of the ceramic substrate 2 and the spacer 36 is sandwiched between the intaglio plate 40 and the film 46, and the pressure plate 37 is used. Insert it from above and below.
The pressure plate 37 is provided with a heat-resistant O-ring 38 made of rubber on the outer periphery.
A notch 39 is provided in the central portion of so as not to hit the surface of the ceramic substrate 2. The pressure plate 37 is heated and pressed by the press jig 45, and then the compressed air 35 is sent to the pressure plate 37 to be pressed between the intaglio 40 and the ceramic substrate 2. At the time of this bonding, the heater temperature was set to 170 ° C. because the compressed air 35 slightly lowers the thermal conductivity. As a result, it was confirmed that the substrate did not crack and the transferability was good.

Next, as a transfer step, the temperature of the intaglio 40 and the ceramic substrate 2 bonded as shown in FIG. 6 is lowered to room temperature, and then the intaglio 40 is peeled from the ceramic substrate 2 to form the first conductor pattern 3. Dried conductor paste 4
3 is transferred. At this time, since the intaglio 40 is highly flexible, the intaglio 40 can be bent at an angle of 90 ° or more. As a result, the intaglio plate 40 can be easily peeled off.

Next, the ceramic substrate 2 to which the dried conductor paste 43 has been transferred as described above is subjected to the peak temperature 850.
Bake under a temperature profile of ° C. Since the conductor pattern is formed on the ceramic substrate 2 to be fired through the adhesive layer 44, combustion gas is vigorously generated from the adhesive layer 44 depending on the setting of firing conditions, which may cause a defect in the conductor pattern. Peeling and deformation may occur. In order to prevent the occurrence of such a problem, the temperature corresponding to the temperature from the start to the end of the burning of the adhesive layer 44 is 20.
The temperature gradient during the temperature increase from 0 ° C to 500 ° C is set to 200 ° C / H.
It is desirable to be r or less.

Through the above steps, the first conductor pattern 3 is formed, the minimum line width is 10 μm, and the minimum line interval is 20.
7 μm, a conductor film thickness after firing of 10 μm, a via diameter of 50 μm, and a via height of 60 μm were obtained. The size of the grooves 12 and 13 was smaller than that of the grooves 12 and 13 because the conductor material shrank due to firing. Now, very fine scattered conductor powder 19 was found between the conductor patterns. The conductor powder 19 scatters together with the binder in the conductor paste when the first conductor pattern 3 is fired, and the insulation property is likely to be lowered as the conductor pattern is made finer. Then, in order to remove the scattered conductor powder 19, a wet etching process is chemically performed.

The method is to dilute nitric acid to a concentration of 30%, immerse the ceramic substrate 2 on which the first conductor pattern 3 is formed in the nitric acid solution at room temperature for about 30 seconds, and then wash with pure water to remove nitric acid and nitric acid. The produced silver nitrate was removed. The conductor powder 19 scattered by this step could be completely removed as shown in FIG.

As a result, the insulation resistance between the patterns of the first conductor pattern 3 is improved from about 100 KΩ to 1 GΩ or more. In addition, the electric resistance of the first conductor pattern 3 is 0.4 Ω at the maximum line length, The area resistance value of was as low as 3.5 mΩ, which was a very small conductor resistance.

Next, as shown in FIG. 8A, the first insulating layer 21 was printed on the ceramic substrate 2 having the first conductor pattern 3 formed thereon by a screen printing method. As this material, a paste of crystallized glass having substantially the same thermal expansion coefficient as that of the ceramic substrate 2 was used. First insulating layer 2
In No. 1, the pattern interval of the first conductor pattern 3 is as narrow as 20 μm, and the film thickness thereof is as thick as 10 μm, so that the bubbles 26 of the insulating layer easily remain. Therefore, the bubbles 2 in the insulating layer
6 is removed. That is, the ceramic substrate 2 is placed in a pressure vessel, compressed air is injected, and a pressure of 5 Kg / cm ^{2 is applied} for 10 seconds.
The air bubbles 26 in the insulating layer can be removed by applying pressure for a minute. As another method for removing the bubbles 26 in the insulating layer, it is also possible to use a method for removing the bubbles 8 generated when the conductive paste 42 is filled in the intaglio 40. Then, the first insulating layer 21 was dried and fired.

Next, the formation of the second conductor pattern 4 is performed as shown in FIG.
As shown in FIG. 5, the first insulating layer 21 was formed by screen printing according to the rule of L / S = 100 μm / 100 μm and baking. The second conductor pattern 4 and the first conductor pattern 3 are electrically connected via the via 11.

By the above manufacturing method, it is possible to obtain a highly reliable ceramic multilayer substrate having a high insulation resistance between conductor patterns, a short circuit defect between conductor patterns, a high manufacturing yield, and a high manufacturing yield.

In addition, since the intaglio surface and the surface of the ceramic substrate 2 are pressed by compressed air pressure in the bonding step, the pressure distribution is made uniform even if the thickness of the substrate is uneven.
It is possible to reduce breakage of the ceramic substrate 2 and transfer failure of a fine conductor pattern.

Furthermore, since the elastic resin base material has a high elastic modulus of 500 kg / cm ² or more, even in a pattern in which the groove spacing of the intaglio is extremely narrow, the grooves are unlikely to be deformed and the intaglio life is very long. As a result, the production cost can be reduced.

(Embodiment 2) The invention according to claim 3 will be described with reference to Embodiment 2 and FIGS. 10 (a) to 10 (e). 10A to 10E are partial cross-sectional views showing the manufacturing process of the second embodiment.

First, as shown in FIG. 10A, the steps up to the step of forming the first conductor pattern 3 were exactly the same as those of the first embodiment.

Next, formation of the first insulating layer 21 formed on the first conductor pattern 3 is performed by using the via 1 as shown in FIG. 10B.
It was formed by screen printing so that all of the above 1 was also printed. As in the first embodiment, the first insulating layer 21 removes bubbles and is dried, and then the via 1 is formed as shown in FIG.
1 was ground by a grinding machine until flattened by several μm. In this step, the entire upper surface of the via 11 is exposed from the first insulating layer 21.

Next, in this state, firing was performed under a temperature profile with a peak temperature of 850 ° C. When fired, FIG.
As shown in (d), the film thickness of the first insulating layer 21 becomes thin due to volume contraction due to firing, and the via 11 is relatively 6 μm thick.
It becomes a projecting shape.

Next, the formation of the second conductor pattern 4 is performed as shown in FIG.
As shown in 0 (e), a ceramic multilayer substrate was formed on the first insulating layer 21 by screen printing according to the rule of L / S = 100 μm / 100 μm and firing. The second conductor pattern 4 and the first conductor pattern 3 are electrically connected via the via 11.

The difference between the second embodiment and the first embodiment is that the first insulating layer 21 is formed on the upper surface of the via 11 and then the upper surface of the via 11 is exposed by grinding, which will be described below. Have an effect.

That is, as the via size and via pitch of the first conductor pattern 3 become smaller, the first insulating layer 2 becomes smaller.
In No. 1, it is extremely difficult to form a pattern in which only the via portion is not printed by screen printing in terms of accuracy. However, according to the means of the second embodiment, the vias 11 that can be formed by the first conductor pattern 3 can be accurately exposed. Therefore, the density of the vias 11 is higher than that of the first embodiment. A wiring pattern and a ceramic multilayer substrate will be obtained. In addition, since the first insulating layer 21 is fired after completely removing bubbles, the insulating property between the conductor patterns is enhanced and a highly reliable ceramic multilayer substrate can be obtained.

(Embodiment 3) The invention according to claim 4 will be described with reference to this Embodiment 3 and FIGS. 11 (a) to 11 (d). 11A to 11D are partial cross-sectional views showing the manufacturing process of the third embodiment.

First, as shown in FIG. 11A, the steps up to the step of forming the first conductor pattern 3 were exactly the same as those of the first embodiment.

Next, formation of the first insulating layer 21 formed on the first conductor pattern 3 is performed by using the via 1 as shown in FIG. 11B.
It was formed by screen printing so that all of the above 1 was also printed. As in the first embodiment, the first insulating layer 21 was defoamed, dried, and then fired under a temperature profile with a peak temperature of 850 ° C. Then, as shown in FIG. 11 (c), the first insulating layer 27 baked by a polishing machine is polished,
The surface of the fired first insulating layer 27 was planarized by polishing the fired first insulating layer 27 until all the vias 11 were completely exposed.

Next, an adhesive layer is applied to the surface of the substrate obtained in the step of FIG. 11C, and then the second conductor pattern 4 is processed by the same step as the step of forming the first conductor pattern 3. An intaglio plate having the above-described groove was formed, and transfer formation was performed using the intaglio plate to form the second conductor pattern 4 as shown in FIG. 11D. The wiring rule of the second conductor pattern 4 is also the same as the wiring rule of the first conductor pattern 3. Since this second conductor pattern 4 is also a fine pattern, it was etched with a nitric acid solution like the first conductor pattern 3 to remove the conductor powder 9 scattered between the conductor patterns.

The third embodiment differs from the second embodiment in that the first insulating layer 21 is baked and then flattened, and has the following advantages. That is, the upper surface of the via 11 and the surface of the first insulating layer 21 are on the same plane, and the planarization is also superior to that of the second embodiment. Not only screen printing but also intaglio transfer can be used, resulting in
It is possible to obtain a ceramic multilayer substrate having a wiring pattern of higher density than that of the second embodiment. The second conductor pattern 4 is also a fine pattern similar to the first conductor pattern 3, but since the conductor powder 9 scattered by the nitric acid solution is removed by etching, the insulation resistance between the conductor patterns becomes high, and as a result, the ceramics. It has the effect of improving reliability as a multilayer substrate.

(Embodiment 4) The invention according to claim 5 will be described with reference to Embodiment 4 and FIGS. 12 (a) to 12 (f). 12A to 12F are partial cross-sectional views showing the manufacturing process of the fourth embodiment.

FIGS. 12A to 12D are shown in FIGS.
The formation of the first insulating layer 21 as shown in FIG.
The steps were exactly the same until firing. Therefore, FIG. 12 (d)
As shown in FIG. 6, the via 11 is in a state of relatively protruding from the fired first insulating layer 27 by about 6 μm.

Next, as shown in FIG. 12E, the upper surface of the via 11 was polished by a polishing machine so as to have the same height as the surface of the fired first insulating layer 27. The subsequent formation of the second conductor pattern 4 was performed by using exactly the same method as in the third embodiment, as shown in FIG.

The fourth embodiment differs from the third embodiment in that it has a grinding process and a polishing process, and has the following advantages.

That is, the second conductor pattern 4 can be a wiring pattern having a higher density than that of the second embodiment, and the same effect as that of the third embodiment can be obtained.

Further, compared to the third embodiment, the state of FIG. 12 (e) can be easily achieved in a short time. That is, since the dry film of the insulating layer 21 is ground in the grinding step, it can be ground very easily in a short time. In the polishing step, only the exposed portion of the via 11 is ground, which is also very easy. Polishing is possible in a short time.

(Fifth Embodiment) The fifth embodiment of the present invention will be described with reference to FIG. FIG. 13 is a partial cross-sectional view showing the manufacturing process of the fifth embodiment.

The first to fourth conductor patterns 3, 4, 5 and 6 were formed in multiple layers on one surface of the ceramic substrate 2 by the same method as in the third embodiment. A dielectric layer 23 was formed on the other surface by screen printing, and the dielectric layer 23 was pressed to remove the bubbles in the same manner as in the method of removing the bubbles 26 of the first embodiment, and then dried and baked. By removing the air bubbles in the dielectric layer 23 as described above, the withstand voltage between the power supply electrode 24 and the ground electrode 25 can be improved, and as a result, the reliability of the ceramic multilayer substrate is improved.

In the fifth embodiment, the dielectric layer 2 described above is used.
A high dielectric constant material with a dielectric constant of 5000 is used as the material of 3,
Although the film thickness is set to 40 μm, it is not limited to this and it is possible to remove bubbles by using a material having another dielectric constant and form the dielectric layer 23 without pinholes.

[0061]

As described above, the present invention is a method for manufacturing a ceramic multilayer substrate, in which a first conductor pattern is formed on a ceramic substrate by intaglio printing, and an insulating layer is formed on the first conductor pattern. , A first groove is formed on the surface of the flexible resin base material in a pattern corresponding to the first conductor pattern, and a second groove is formed from the first groove in a pattern corresponding to the via portion of the first conductor pattern. A step of manufacturing an intaglio formed even deeper, a step of filling the first and second grooves with a conductive paste, defoaming and drying, and a volume reduction amount due to drying of the conductive paste dried in the step. Refilling with an additional conductive paste to compensate for the above, a step of repeating a step of re-defoaming and re-drying a predetermined number of times, and removing a conductive residue remaining on the surface of the intaglio plate after filling the conductive paste. And the intaglio process A step of bonding the lamic substrate by applying heat and pressure within a predetermined range, and a step of peeling the intaglio plate from the ceramic substrate and transferring the pattern of the conductive paste onto the ceramic substrate to form the first conductor pattern. A step of printing a first insulating layer on at least the first conductor pattern, and a second step on the first insulating layer.
A method for producing a ceramic multilayer substrate, comprising: a step of printing and forming a conductor pattern; and a step of chemically wet-etching at least one of the fired first conductor pattern and the second conductor pattern, and then cleaning the ceramic multilayer substrate. , The conductive residue remaining on the surface of the intaglio plate after being filled with the conductive paste is removed, and at least one of the fired first conductor pattern and the second conductor pattern is chemically wet-etched to form a space between the conductor patterns. The insulating property can be improved, and as a result, the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a ceramic multilayer substrate according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a manufacturing process according to an embodiment of the present invention.

3A to 3D are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a manufacturing process according to an embodiment of the present invention.

5 (a) and 5 (b) are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

FIG. 6 is a sectional view showing a manufacturing process according to an embodiment of the present invention.

7A to 7B are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

8 (a) and 8 (b) are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

FIG. 9 is a sectional view showing a manufacturing process according to an embodiment of the present invention.

10 (a) to 10 (e) are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

11 (a) to 11 (d) are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

12 (a) to 12 (f) are cross-sectional views showing a manufacturing process according to an embodiment of the present invention.

FIG. 13 is a sectional view showing a manufacturing process according to an embodiment of the present invention.

FIG. 14 is a flow chart of a conventional manufacturing process.

[Explanation of symbols]

2 Ceramic substrate 3 First conductor pattern 4 Second conductor pattern 7 through holes 8 bubbles 9 Conductor paste residue 11 beer 12 first groove 13 second groove 19 scattered conductor powder 21 First Insulating Layer 22 Second insulating layer 23 Dielectric layer 24 power electrode 25 ground electrode 26 Bubbles in the insulating layer 27 Fired first insulating layer 30 cloth 31 Wiping Squeegee 35 compressed air 36 Spacer 37 Pressure plate 38 O-ring 39 Notch 40 intaglio 41 Squeegee 42 Conductor paste 43 Dry conductor paste 44 Adhesive layer 45 Press jig 46 films

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenichi Kato             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F term (reference) 5E343 AA02 AA23 BB72 DD01 DD56                       DD64 DD76 EE01 ER52 FF23                       GG11                 5E346 AA02 AA13 AA15 AA32 AA43                       AA51 CC16 DD03 DD13 DD34                       EE23 EE32 FF18 GG06 GG07                       GG08 HH31

Claims (8)

[Claims] 1. A method for producing a ceramic multilayer substrate, comprising forming a first conductor pattern on a ceramic substrate by intaglio printing and forming an insulating layer on the first conductor pattern.
(A) A first groove is formed on the surface of a flexible resin substrate in a pattern corresponding to the first conductor pattern, and a second groove is formed in a pattern corresponding to the via portion of the first conductor pattern. A step of manufacturing an intaglio formed deeper than the groove, (b) a step of filling the first and second grooves with a conductive paste, defoaming and drying, and (c) a drying step (b). Refilling an additional conductive paste in order to compensate for the reduced volume of the conductive paste due to drying, re-defoaming and re-drying a predetermined number of times, and (d) adding the conductive paste. A step of removing a conductor residue remaining on the surface of the intaglio plate after filling, (e) a step of attaching the intaglio plate and the ceramic substrate by applying heat and pressure within a predetermined range, and (f) a ceramic plate of the intaglio plate. Peel off the substrate and use conductive paste A step of transferring the pattern onto a ceramic substrate to form a first conductor pattern; (g) a step of printing a first insulating layer on the first conductor pattern; and (h) a first insulating layer. A step of printing and forming a second conductor pattern on the substrate, (i) chemically wet-etching at least one of the first conductor pattern after the step (f) and the second conductor pattern after the step (h), and thereafter. A method for manufacturing a ceramic multilayer substrate, comprising: a step of cleaning. 2. The wet etching in step (i) is 25-4.
The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein 0% nitric acid is used and etching is performed for 0.5 to 5 minutes. 3. In the step (g), a first insulating layer is formed by printing on the entire surface at least on the first conductor pattern, air bubbles are removed from the first insulating layer, and then dried to obtain a dry film of the first insulating layer. 2. The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding. 4. In the step (g), a first insulating layer is formed by printing on the entire surface of at least the first conductor pattern, air bubbles are removed from the first insulating layer, followed by drying, and the first insulating layer is formed after firing. The method for manufacturing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding. 5. In the step (g), a first insulating layer is formed on the entire surface by printing on at least the first conductor pattern, air bubbles are removed from the first insulating layer, and then dried to obtain a dry film of the first insulating layer. The method for producing a ceramic multilayer substrate according to claim 1, wherein the via portion of the first conductor pattern is exposed by polishing or grinding, and after firing, polishing or grinding is performed again. 6. The method for producing a ceramic multilayer substrate according to claim 1, wherein a dielectric layer is formed by printing on a part of the ceramic substrate, bubbles are removed from the dielectric layer, and then dried. 7. The method for producing a ceramic multilayer substrate according to claim 1, wherein in step (e), pressure is applied between the intaglio and the ceramic substrate and the press by compressed air. 8. The flexible resin substrate has an elastic modulus of 50.
The method for producing a ceramic multilayer substrate according to claim 1, which has a pressure of 0 kg / cm ² or more.