JPH11220256A - Manufacturing method of ceramic wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve coherency-between a ceramic substrate and the hardening matter of a conductive paste, by forming a metal coating onto the wall surface of a through hole being formed on the ceramic substrate, and by filling conductive paste into the through hole where the metal coating is formed onto the wall surface. SOLUTION: A through hole 12 is formed on a ceramic substrate 10, and a metal coating 14 is formed on the wall surface of the through hole 12. Conductive paste 16 is filled into the through hole 12, a heat release sheet 18 is applied onto both sides of the ceramic substrate 10 while being pressed, and both end faces of the through hole are blocked. Then, the conductive paste 16 is hardened by heating and at the same time the heat release sheet 18 and the metal coating 14 are eliminated. Finally, a circuit 20 is formed on the surface of the ceramic substrate 10 for manufacturing a ceramic wiring board, thus improving coherency between a ceramic substrate 10 and the hardening matter of filled conductive paste 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 ceramic wiring board having a through hole filled with a metal material and having a circuit formed on a surface thereof.

[0002]

2. Description of the Related Art In recent years, as the miniaturization of electronic devices has accelerated,
Ceramic wiring boards are progressing in the direction of miniaturization, high integration, and compatibility with high frequencies. The characteristics of ceramic wiring boards include the ability to dissipate heat generated from electronic components such as ICs and the ground circuit for high frequencies. Is a problem. Therefore, as a countermeasure, the ground circuit is reinforced by filling the through hole with a metal object to increase the conductivity of the through hole, and the electronic component is mounted on the through hole filled with the metal object to reduce the electronic component. It has been practiced to dissipate heat to the surface opposite to the surface on which it is mounted to improve heat dissipation.

As a method of forming a through hole filled with a metal material, for example, as described in JP-A-3-276790, a conductive paste containing metal powder or the like in a through hole formed in a ceramic substrate is disclosed. After filling, the conductive paste is solidified by heating, and then the solidified material (metallic material) of the conductive paste protruding from the substrate is removed by polishing or the like to flatten the end face of the solidified conductive paste. And Japanese Patent Application Laid-Open No. 5-1672 / 1993.
As described in No. 46, a method of filling a through-hole formed in a ceramic substrate with a low-shrinkage conductive paste and then heating to solidify the conductive paste is used.

However, when the through holes filled with the solidified conductive paste are formed by these methods, there is a problem that the adhesion between the ceramic substrate and the solidified conductive paste is low. Therefore, a thick film paste is applied to the portion of the through hole filled with the solidified conductive paste to cover the end surface of the through hole, and then the thick film paste is baked to form a peel prevention layer on the end surface of the through hole.
Prevention of peeling of solidified conductive paste has been studied. However, in the case of this method, it is necessary to form a land on the surface of the ceramic substrate around the through hole in order to obtain the close contact between the thick film paste and the ceramic substrate,
There has been a problem in that there is a limitation in circuit design and a problem that the size of the ceramic wiring board is large. Therefore, there is a demand for a method of manufacturing a ceramic wiring board that can obtain a ceramic wiring board having excellent adhesion between a ceramic substrate and a solidified product of a filled conductive paste.

[0005] Further, a wiring board obtained by solidifying the conductive paste and removing the solidified material of the conductive paste from the portion protruding from the substrate by polishing or the like has a problem that insulation between circuits formed on the surface is reduced. There was a problem that sometimes. This is because the solidified conductive paste, which has been refined by polishing, adheres to the substrate surface and then adheres to an insulating portion between circuits to be formed. I have. Therefore, there is a demand for a method of manufacturing a ceramic wiring board having an excellent insulating property, since an excessive solidified paste of the conductive paste hardly remains in an insulating portion between circuits formed on the surface of the wiring board.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to fill a through hole formed in a ceramic substrate with a conductive paste. A method for manufacturing a ceramic wiring board, comprising flattening a conductive paste and then forming a circuit on the surface of the ceramic substrate, wherein the ceramic has excellent adhesion between the ceramic substrate and a solidified conductive paste filled therein. An object of the present invention is to provide a method for manufacturing a ceramic wiring board from which a wiring board can be obtained.

[0007] In addition, the insulating portion on the surface of the ceramic wiring board,
An object of the present invention is to provide a method for manufacturing a ceramic wiring board in which a solidified material of an unnecessary conductive paste hardly remains.

[0008]

According to a first aspect of the present invention, there is provided a method for manufacturing a ceramic wiring board, comprising filling a through-hole formed in a ceramic substrate with a heat-solidifying conductive paste, and then applying the conductive paste. In a method for manufacturing a ceramic wiring board, which is manufactured by flattening and then forming a circuit on a surface of a ceramic substrate, a method of filling a conductive paste in a through hole is performed by forming a metal film on a wall surface of the through hole and then forming the metal film on the wall surface. The method is characterized in that a conductive paste is filled into a through hole having a metal film formed thereon.

According to a second aspect of the present invention, there is provided a method of manufacturing a ceramic wiring board according to the first aspect, wherein the metal film is a copper film.

According to a third aspect of the present invention, in the method for manufacturing a ceramic wiring board according to the first or second aspect, the conductive paste is a paste containing silver and rhodium. It is characterized by the following.

According to a fourth aspect of the present invention, in the method for manufacturing a ceramic wiring board according to any one of the first to third aspects, a metal film is formed on a wall surface of the through hole. In this case, a metal film is formed on the surface of the ceramic substrate, and after the conductive paste is flattened, the metal film on the surface of the ceramic substrate is removed.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a ceramic wiring board according to any one of the first to fourth aspects, wherein the conductive paste is filled in the through holes. After filling the through-hole with the conductive paste, the method of flattening the conductive paste is performed by applying a heat-peelable sheet to both sides of the ceramic substrate while applying pressure, closing both end surfaces of the through-hole, and then heating. And removing the heat-peelable sheet.

According to a sixth aspect of the present invention, there is provided a method for manufacturing a ceramic wiring board according to any one of the first to fourth aspects, wherein the through-hole is filled with a conductive paste. The method of flattening the conductive paste is to attach a gas permeable sheet to one surface of the ceramic substrate, close one end surface of the through hole, fill the through hole with the conductive paste, and then from the through hole. After the protruding portion of the conductive paste is removed, the air-permeable sheet is peeled off.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a ceramic wiring board according to any one of the first to fourth aspects, wherein the conductive paste is filled in the through holes. The method of flattening the conductive paste is such that after filling the through-hole with the conductive paste, the conductive paste is solidified, and then the solidified portion of the conductive paste protruding from the through-hole is removed by polishing. The method is characterized by:

According to the present invention, since the metal bond is formed between the metal film formed on the wall surface of the through hole and the solidified conductive paste, the filled conductive paste slightly shrinks when solidified. However, it is considered that separation hardly occurs between the ceramic substrate and the solidified conductive paste, and the adhesion is improved.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a ceramic wiring board according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view illustrating the steps of a method for manufacturing a ceramic wiring board according to one embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating the steps of another embodiment of the method for manufacturing a ceramic wiring board according to the present invention. FIG. 3 is a cross-sectional view for explaining the steps of still another embodiment of the method for manufacturing a ceramic wiring board according to the present invention.

One embodiment of the method for manufacturing a ceramic wiring board according to the present invention is a method of manufacturing a ceramic wiring board, as shown in FIG.
2 is used. Examples of the ceramic substrate 10 include inorganic plates such as alumina, zirconia, and glass ceramic. The method of forming the through-hole 12 is not particularly limited. For example, a method of forming a through-hole by punching or the like before baking and baking and forming, or a method of opening after baking by laser or the like And the like. The size of the through hole 12 and the thickness of the ceramic substrate 10 are not particularly limited, and may be appropriately adjusted according to the characteristics of the ceramic wiring board to be manufactured.

Then, as shown in FIG. 1B, a metal film 14 is formed on the wall surface of the through hole 12. Then, after the conductive paste 16 is filled into the through holes 12 in a later step, the ceramic wiring board obtained by solidifying the conductive paste 16 has excellent adhesion between the ceramic substrate 10 and the solidified conductive paste. Ceramic wiring board. This is because if the filled conductive paste is slightly shrunk when it is solidified, peeling occurs between the ceramic substrate 10 and the solidified conductive paste. When the film 14 is formed, a metal bond is formed between the metal film 14 and the solidified conductive paste, so that peeling between the ceramic substrate 10 and the solidified conductive paste hardly occurs. Is thought to improve.

Examples of the metal forming the metal film 14 include copper and nickel. In the case of copper, the adhesion between the ceramic substrate 10 of the obtained ceramic wiring board and the solidified conductive paste is particularly high. Excellent and preferred. In addition,
When the thickness of the metal film 14 is 0.1 μm or more,
In particular, the adhesiveness is excellent and preferable. The method for forming the metal film 14 on the wall surface of the through hole 12 is not particularly limited, and examples thereof include a sputtering method, a CVD method (chemical vapor deposition), and a plating method.

If the metal film 14 is formed after the wall surface of the through hole 12 is roughened before the metal film 14 is formed, the adhesion between the ceramic substrate 10 and the metal film 14 is improved. This is preferable because the adhesion between the ceramic substrate 10 of the ceramic wiring board to be obtained and the solidified conductive paste is improved. As a method of roughening the wall surface of the through-hole 12, for example, a method of treating with hydrofluoric acid, phosphoric acid, alkali, or the like can be used.

Next, as shown in FIG. 1C, the conductive paste 16 is filled in the through holes 12. The conductive paste 16 is not particularly limited as long as it is a heat-solidification type paste that becomes a metal when solidified. For example, the paste contains silver powder or copper powder. Examples of the paste include a paste and a paste containing gold powder. In the case of a paste containing silver and rhodium, the difference in volume before and after solidification is small, so that the conductive paste 16 can be easily flattened, which is preferable. The method for filling the conductive paste 16 is not particularly limited, and is performed by a printing method, a press-fitting method, or the like.
Fill 6.

Next, as shown in FIG. 1D, a heat-peelable sheet 18 is attached to both surfaces of the ceramic substrate 10 while applying pressure, thereby closing both end surfaces of the through-holes 12 and simultaneously pressing the surface of the ceramic substrate 10. Metal film 14 formed on
And the end face of the conductive paste 16 are substantially flush with each other,
The portion of the conductive paste 16 protruding from the end surface of the through hole 12 is spread on the surface of the metal film 14 around the through hole 12 to flatten the conductive paste 16.

The heat-peelable sheet 18 is a sheet formed of a resin that forms a solid that can be peeled off by heat, or a resin obtained by adding an insulating filler to these resins. It is to be noted that, in place of the heat-peelable sheet 18, a solvent or an alkali-peelable sheet may be used for flattening in the same manner. 16 is deteriorated when it is solidified, and peeling tends to be difficult.
The heat-peelable sheet 18 is preferred.

Next, as shown in FIG. 1 (e), the conductive paste 16 is solidified by heating, and the heat-peelable sheet 18 is removed. The heating conditions are such that the conductive paste 16 is solidified and the temperature and time are appropriately adjusted so that the heat-peelable sheet 18 can be removed before heating. In addition,
After the heat-peelable sheet 18 is once removed by heating, the conductive paste 16 may be solidified by further heating. The heating in the latter half may not be performed in this step, but may be performed after several subsequent steps.

Next, as shown in FIG. 1F, the metal film 14 on the surface of the ceramic substrate 10 is removed. Then, when the portion of the conductive paste 16 protruding from the end surface of the through hole 12 is flattened, the solidified conductive paste 16 spread on the surface of the metal film 14 around the through hole 12 also becomes Removed together with the ceramic substrate 1
The solidified surplus of the conductive paste 16 hardly remains on the insulating portion on the surface of No. 0. This is because the conductive paste 16 is stretched and thinned when the heat-peelable sheet 18 is applied while being pressed, and the solidified material of the conductive paste 16 removed in this step is also very thin. This is because the metal film 14 is easily removed by a spray pressure or an osmotic pressure of the etchant when the metal film 14 is removed.

Next, as shown in FIG. 1G, a circuit 20 is formed on the surface of the ceramic substrate 10 to manufacture a ceramic wiring board. As a result, a ceramic wiring board having excellent adhesion between the ceramic substrate 10 and the solidified product of the conductive paste 16 and having less excess solidified material of the conductive paste 16 remaining on the insulating portion on the surface of the ceramic substrate 10 is obtained. .

The method of forming the circuit 20 is as follows.
There is no particular limitation, and sputtering, CVD
Method, plating method and the like. In this case, after forming a resist on a portion of the surface of the ceramic substrate 10 where the circuit 20 is not formed, a metal for forming the circuit 20 is applied to a portion where the resist is not formed to form the circuit 20. The circuit 2 is provided on the entire surface of the ceramic substrate 10.
After forming the film for forming the circuit 0, the portion where the circuit 20 is to be formed is covered with an etching resist, and then the film of the uncovered portion is removed to form the circuit 20, and then the etching resist is removed. It may be formed by a removing method. The circuit 20 is not limited to being formed only on the surface of the ceramic substrate 10, but may be formed on the surface of a solidified conductive paste 16 as well.

In the above embodiment, the metal film 14 is formed on the wall surface of the through hole 12 and the entire surface of the ceramic substrate 10.
The embodiment in which the ceramic substrate 1 is formed has been described.
However, the present invention is not limited to the case where the metal film 14 is formed on at least the wall surface of the through hole 12, and the adhesion between the ceramic substrate 10 and the solidified conductive paste 16 is excellent. A ceramic wiring board is obtained.

In the above embodiment, as a method of flattening the conductive paste 16, after filling the through hole 12 with the conductive paste 16, the heat-peelable sheet 18 is pressed on both surfaces of the ceramic substrate 10. Paste while attaching 1
After closing both the end faces of No. 2, the embodiment of the method of removing the heat-peelable sheet 18 by heating (hereinafter referred to as Method A) has been described, but the present invention is not limited to this method. After attaching a breathable sheet to one surface of the ceramic substrate 10 to close one end surface of the through hole 12, the through hole 12 is filled with the conductive paste 16, and then the through hole 1 is filled.
After removing the portion of the conductive paste 16 protruding from the second, the air-permeable sheet is peeled off (hereinafter referred to as method B), or the conductive paste 16 is filled in the through-hole 12 and then filled with the conductive paste 16. And then through-hole 1
After a method of polishing and removing a solidified portion of the conductive paste 16 at a portion protruding from the second (hereinafter, referred to as a method C) or supplying an amount of the conductive paste 16 in anticipation of a shrinkage rate at the time of solidification, A method of flattening by solidification may be used. In these cases as well, a ceramic wiring board is obtained in which the solidified surplus conductive paste 16 hardly remains on the insulating portion on the surface of the ceramic substrate 10. The method A is preferable because it can be easily flattened.

As a specific method of the above method B, for example, as shown in FIG. 2C, a gas permeable sheet 22 is formed on one surface of the ceramic substrate 10 having the metal film 14 formed on the wall surface of the through hole 12. paste. The air permeable sheet 22 is a sheet through which air in the through-holes 12 passes through the air permeable sheet 22 when the conductive paste 16 is filled, and includes, for example, paper having an opening such as Japanese paper or irregularities on the surface. A sheet through which air escapes in a plane direction through the concave portion may be used.

Next, as shown in FIG. 2D, after the conductive paste 16 is filled into the through holes 12 from the side where the air permeable sheet 22 is not attached, the air permeable sheet 22 is not attached. By removing the portion of the conductive paste 16 protruding to the side of the surface and then peeling off the breathable sheet 22, the conductive paste 16 is flattened as shown in FIG. As a method of removing the conductive paste 16, for example, the protruding portion of the conductive paste 16 is transferred to the cloth by moving a cloth impregnated with a solvent along the surface of the ceramic substrate 10.

As a specific method of the method C, for example, as shown in FIG. 3C, the through hole 12 of the ceramic substrate 10 having the metal film 14 formed on the wall surface of the through hole 12 is formed.
The conductive paste 16 is supplied so as to fill the whole. Next, after heating to solidify the conductive paste 16, FIG.
As shown in (d), a second metal film 24 is formed on the surface of the ceramic substrate 10. As a method of forming the second metal film 24, a method similar to the method of forming the metal film 14 formed on the wall surface of the through hole 12 can be used.

Next, as shown in FIG. 3 (e), using a brush-type, buff-type, or sheet-type abrasive 26, the conductive portions of the surface protruding from the surface of the second metal film 24 and the surface of the ceramic substrate 10 are formed. The conductive paste 16 is planarized by mechanically polishing the conductive paste 16. In the case of this method, even when the conductive paste 16 having a large shrinkage rate is used, a large amount of the conductive paste 16 is supplied and the solidified material of the conductive paste 16 is projected from the surface of the ceramic substrate 10 to obtain a flat surface. It is possible and preferable.

Another specific method of the method C is a method in which the second metal film 24 is not formed, and the conductive paste 1 filled in the through hole 12 having the metal film 14 formed on the wall surface is used.
6 is heated and solidified, and then the surface of the metal film 14 formed on the surface of the ceramic substrate 10 and the conductive paste 16 at the protruding portion are mechanically polished using an abrasive 26 to form a conductive paste. 16 is flattened.

[0035]

(Example 1) As a ceramic substrate, 0.5
0.64 mm thick alumina 96 with a through hole of φ
% Of the substrate was used. Then, as a pretreatment for forming a metal film, the wall surface of the through hole and the entire surface of the ceramic substrate are roughened by immersing in phosphoric acid at 330 ° C. for 90 seconds, and then electroless copper plating is performed. A copper film was formed to a thickness of 0.1 μm on the entire wall surface of the ceramic substrate.

Next, the through-hole was filled with a conductive paste (trade name: TR6983, manufactured by Tanaka Kikinzoku Co., Ltd., containing silver and rhodium). This method employs an emulsion thickness of 25 μm.
The printing was repeated using a m screen, and the through-hole was filled with a conductive paste.

Next, a heat-peelable sheet (manufactured by Nitto Denko Corporation, product name Riba Alpha 31) is provided on both sides of the ceramic substrate.
94M) is applied under pressure to close both end surfaces of the through hole, so that the conductive paste protruding from the end surface of the through hole is spread on the surface of the copper film around the through hole. Then, the conductive paste was flattened.

Next, the conductive paste is heated at 125 ° C. for 10 minutes to solidify the conductive paste, the heat-peelable sheet is removed, and the resultant is treated with an aqueous cupric chloride solution to etch the copper film on the surface of the ceramic substrate. Removed. Next, the conductive paste was baked by heating at 850 ° C. for 10 minutes in the air, and then electroless copper plating was performed to form a circuit on the surface of the ceramic substrate to obtain a ceramic wiring board.

Example 2 A ceramic was formed in the same manner as in Example 1 except that the time of the electroless copper plating was extended, and a copper film was formed to a thickness of 0.2 μm on the wall surfaces of the through holes and the entire surface of the ceramic substrate. A wiring board was obtained.

Example 3 As a method of flattening the conductive paste, a gas permeable sheet (Japanese paper) was attached to one surface of a ceramic substrate to close one end surface of a through hole. Similarly, the conductive paste is filled in the through-hole, and then the conductive paste in a portion protruding from the through-hole on the printed surface is removed by wiping with a cloth soaked with acetone, and then heated at 125 ° C. for 10 minutes. The procedure of Example 1 was repeated, except that the conductive paste was solidified and then the air-permeable sheet was peeled off (method B).
A ceramic wiring board was obtained.

(Example 4) As a method of flattening the conductive paste, the conductive paste filled in the through-holes was 125
After heating and solidifying at 10 ° C. for 10 minutes, the method was performed in the same manner as in Example 1 except that the solidified portion of the conductive paste projecting from the through hole was polished and removed using sandpaper (method C). Similarly, a ceramic wiring board was obtained.

(Comparative Example 1) No roughening of the wall surface of the through hole, no electroless copper plating, and flattening of the conductive paste (attaching the heat-peelable sheet while pressing it). A ceramic wiring board was obtained in the same manner as in Example 1, except that the step was not performed and the copper film was not removed before firing the conductive paste.

(Comparative Example 2) Except that the wall surface of the through hole was not roughened, electroless copper plating was not performed, and the copper film was not removed before firing the conductive paste. In the same manner as in Example 1, a ceramic wiring board was obtained.

(Evaluation and Results) The adherence of the solidified product of the filled conductive paste and the flatness of the solidified product of the filled conductive paste of the ceramic wiring boards obtained in the respective examples and comparative examples were evaluated. The remaining state of the solidified conductive paste was evaluated. The adhesiveness of the solidified product of the filled conductive paste is determined by pressing the iron pin with a sharp tip in contact with one end surface of the solidified product of the filled conductive paste to solidify the filled conductive paste. The force when the object came off from the ceramic substrate was measured and defined as the adhesion.

The flatness of the solidified conductive paste was measured using a surface roughness meter (dektak3030, manufactured by sloan) using the solidified solid of the filled conductive paste and the surrounding ceramic substrate. Was linearly scanned, and the difference between the height of the solidified portion of the filled conductive paste with respect to the surrounding ceramic substrate was measured in 10 holes, and the maximum and minimum values were determined. The residual state of the solidified conductive paste is visually inspected using a magnifying glass of 10 times for the presence or absence of the solidified conductive paste remaining on the surface of the ceramic wiring board. , And the case where it did not remain was evaluated as ○.

The results are shown in Table 1. As shown in Table 1, in each of the examples, the adhesion between the ceramic substrate and the solidified product of the filled conductive paste was superior to that in each of the comparative examples, and the remaining on the surface of the ceramic wiring board. It was confirmed that the amount of the solidified conductive paste was small. Further, in each example, it was confirmed that the flatness of the solidified product of the filled conductive paste was superior to Comparative Example 1.

[0047]

[Table 1]

[0048]

According to the method for manufacturing a ceramic wiring board of the present invention, a ceramic wiring board having excellent adhesion between a ceramic substrate and a solidified conductive paste filled therein can be obtained.

According to the method for manufacturing a ceramic wiring board according to the second aspect of the present invention, in addition to the above-described effects, a ceramic wiring board in which solidified surplus conductive paste hardly remains in the insulating portion on the surface of the ceramic wiring board. Is obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a process of an embodiment of a method for manufacturing a ceramic wiring board according to the present invention.

FIG. 2 is a cross-sectional view illustrating steps of another embodiment of the method for manufacturing a ceramic wiring board according to the present invention.

FIG. 3 is a cross-sectional view illustrating a process in still another embodiment of the method for manufacturing a ceramic wiring board according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 ceramic substrate 12 through hole 14 metal film 16 conductive paste 18 heat-peelable sheet 20 circuit 22 breathable sheet 24 second metal film 26 abrasive

Claims (7)

[Claims] 1. A ceramic wiring board manufactured by filling a through hole formed in a ceramic substrate with a thermosetting conductive paste, flattening the conductive paste, and then forming a circuit on the surface of the ceramic substrate. In the manufacturing method, the method of filling the through hole with the conductive paste is a method of forming a metal film on the wall surface of the through hole and then filling the through hole with the metal film on the wall surface with the conductive paste. Characteristic method for manufacturing a ceramic wiring board. 2. The method according to claim 1, wherein the metal film is a copper film. 3. The method for producing a ceramic wiring board according to claim 1, wherein the conductive paste is a paste containing silver and rhodium. 4. When a metal film is formed on the wall surface of the through hole, the metal film is formed on the surface of the ceramic substrate, and after the conductive paste is flattened, the metal film on the surface of the ceramic substrate is removed. The method for manufacturing a ceramic wiring board according to any one of claims 1 to 3, wherein: 5. After filling the through hole with a conductive paste,
The method of flattening the conductive paste is such that after filling the through-hole with the conductive paste, a heat-peelable sheet is applied to both surfaces of the ceramic substrate while applying pressure to close both end surfaces of the through-hole, and then heated. The method for producing a ceramic wiring board according to any one of claims 1 to 4, wherein the method is a method for removing the heat-peelable sheet by heating. 6. After filling the through-hole with a conductive paste,
The method of flattening the conductive paste is as follows: After attaching a breathable sheet to one surface of the ceramic substrate and closing one end surface of the through hole, filling the through hole with the conductive paste, and then projecting from the through hole The method for manufacturing a ceramic wiring board according to any one of claims 1 to 4, wherein the method is a method of removing a portion of the conductive paste and then peeling off the permeable sheet. 7. After filling the through-hole with the conductive paste,
A method of flattening a conductive paste is a method of filling a conductive paste in a through-hole, solidifying the conductive paste, and then polishing and removing a solidified portion of the conductive paste protruding from the through-hole. The method for manufacturing a ceramic wiring board according to any one of claims 1 to 4, wherein