JP2001185824A - Ceramic wiring board and method of manufacturing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass ceramic wiring board which can control the shrinkage in plan direction and enable fine wiring with excellent surface. SOLUTION: The glass ceramic wiring board on the surface of which the area ratio of voids is adjusted to <=5% is manufactured in such a way that green sheets composed of a glass ceramic composition containing >=20 vol.% amorphous component after burning are prepared, and wiring circuit layers composed of high-purity metallic conductors containing >=99.5 wt.% metallic component are respectively formed on the surfaces of the green sheets. Then the green sheets are laminated upon another and a constraining sheet which is composed mainly of a hardly sinterable ceramic material and containing 0.5-15 vol.% amorphous component is formed on at least one surface of the laminated green sheet body. Finally, the laminated body is sintered and the constraint sheet is removed.

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 suitable for a multilayer wiring board and a package for accommodating a semiconductor element.

[0002]

2. Description of the Related Art In recent years, chip components such as semiconductor elements have been reduced in size and weight, and it has been desired to reduce the size and weight of wiring boards on which these are mounted. In response to such demands, ceramic multilayer wiring boards in which an internal wiring circuit layer is formed within the board are capable of high-density wiring and can be made thinner, so they are important in today's electronics industry. Have been watched.

Conventionally, as a ceramic multilayer wiring board used for a package or the like for housing a semiconductor element,
A wiring circuit layer made of a metal such as W or Mo is formed on the surface or inside of a ceramic insulating substrate such as alumina.
A cavity is formed in a part of the insulating substrate, a semiconductor element is accommodated in the cavity, and the cavity is hermetically sealed by a lid.

In recent years, a high-density package is used for a semiconductor element storage package for mounting a semiconductor element such as an IC or an LSI, and a wiring board applied to a hybrid integrated circuit device on which various electronic components are mounted. , Lower resistance, smaller size and lighter weight are required, a lower dielectric constant is obtained as compared with conventional alumina-based ceramic materials, and Cu is used as a wiring circuit layer.
Therefore, ceramic wiring boards made of glass or a mixture of glass and a ceramic filler and having a firing temperature of 1000 ° C. or lower and using a so-called glass ceramic material as an insulating substrate have attracted much attention because a low-resistance metal such as such can be used. .

However, in such a glass ceramic wiring board, a method of forming a wiring conductor layer is as follows.
A metallizing paste mainly composed of a wiring conductor made of a metal such as Cu or Ag is printed on a surface of a green sheet formed by molding a glass ceramic composition into a sheet shape by a screen printing method or the like and then fired. . However, when such a printing method is used, it is difficult to form a wiring having a width of 100 μm or less, which has been a factor which hinders achievement of further higher density, smaller size and lighter weight which will be required in the future. Also, regarding the electric resistance, since the wiring conductor layer is formed with a conductor paste containing metal powder as a main conductor, there are many voids in the wiring circuit layer after firing, so that it is difficult to reduce the resistance of the wiring conductor layer. was there.

As a method for solving this problem, a method is known in which a wiring circuit layer in a glass ceramic green sheet is formed by etching a metal foil (JP-A-63-14493). However, when the metal foil and the glass ceramic are co-fired, the metal foil itself is substantially dense and hardly shrinks, so that there is a problem that the substrate is warped and cracks occur, which makes practical use difficult.

Therefore, a ceramic sheet made of a hardly sinterable ceramic material which does not sinter at a firing temperature is formed on both sides of a laminated body of glass ceramic green sheets, and then a layer of an inorganic composition is formed. (Japanese Patent Application Laid-Open No. 7-86743) is known which enables simultaneous firing of a metal foil and a glass ceramic by suppressing shrinkage in a plane direction in (1). Japanese Patent Application Laid-Open Nos. 4-2939778 and 5-28867 disclose a method of firing a green sheet obtained by printing and applying a conductive paste on the surface of the green sheet while also suppressing shrinkage in the planar direction.
And JP-A-5-102666.

[0008]

Normally, in the above method, the bonding between the glass ceramic green sheet and the restraining sheet is performed by an organic component such as an organic binder contained in the sheet, and the organic component is After decomposition and volatilization, the contraction of the green sheet is restricted only by the frictional force between the restriction sheet and the green sheet.

However, in order to reduce the sinterability, the restraint sheet usually contains only a high-temperature sintering component such as alumina, and contains almost no glass component that generates a liquid phase. In the binding process, it exists as a porous body.

Therefore, when such a constrained sheet is laminated and fired on the surface of a green sheet made of glass powder or a mixture of glass powder and ceramic filler powder, the glass component in the green sheet becomes liquid phase during the sintering process. As a result, the liquid phase component diffuses toward the constraining sheet side, resulting in a problem that the amount of glass on the surface of the green sheet decreases and the surface on which the constraining sheets are laminated tends to be insufficiently sintered.

Such a phenomenon is observed as the amount of the amorphous component after sintering of the glass ceramic composition on the glass ceramic green sheet side increases, and the surface of the wiring substrate becomes a rough surface having many voids. As a result, there are problems such as a decrease in substrate strength and a spread of plating when a wiring circuit layer on the substrate surface is plated.

Accordingly, an object of the present invention is to provide a wiring substrate using glass ceramics as an insulating substrate, which can stably control the shrinkage in the planar direction, enables fine wiring, and has a good surface condition of the substrate. An object of the present invention is to provide a ceramic wiring board and a method for manufacturing the same.

[0013]

Means for Solving the Problems The present inventors have made intensive studies on the above-mentioned problems, and as a result, have found that an appropriate amount of glass is contained in a hardly sinterable restraint sheet laminated on a glass ceramic green sheet. As a result, it has been found that the object can be achieved by preventing the diffusion of the liquid phase component from the glass ceramic green sheet and realizing effective suppression of shrinkage by the restraining sheet.

That is, the ceramic wiring board of the present invention is formed on the surface and / or inside of an insulating substrate made of glass ceramic and containing an amorphous component of 20% by volume or more.
A wiring board on which a wiring circuit layer made of a high-purity metal conductor having a metal component content of 99.5% by weight or more is formed, wherein the void area occupancy on the outermost surface of the insulating substrate is 5% or less. It is characterized by the following.

The method of manufacturing the above ceramic wiring board includes the steps of (a) forming a green sheet made of a glass ceramic composition having an amorphous component content of 20% by volume or more after firing. (B) forming a wiring circuit layer made of a high-purity metal conductor having a metal component content of 99.5% by weight or more on the surface of the green sheet; and (c) forming the wiring circuit layer. Laminating a green sheet; and (d) restraining at least one surface of the green sheet laminate to have a non-sinterable ceramic material as a main component and an amorphous component in an amount of 0.5 to 15% by volume. (E) baking a laminate of the constrained sheet and the green sheet laminate to produce a glass-ceramic substrate having the constrained sheet on its surface; (f) It is desirable that the serial glass-ceramic substrate and a step of removing the binding sheet.

In the above-mentioned manufacturing method, the hardly sinterable ceramic material may be Al ₂ O ₃ , SiO ₂ , Mg
It is preferable that at least one selected from the group consisting of O, ZrO ₂ , BN, and TiO ₂ be the main component, and the softening point of the amorphous component contained in the restraining sheet is determined by firing the glass ceramic composition. It is desirable that the temperature be lower than the temperature.

According to the above-described ceramic wiring board and the method of manufacturing the same, it is desirable that the wiring circuit layer is made of the metal foil, and the wiring circuit layer made of the metal foil is formed on the surface of the insulating substrate or the green sheet. It is desirable to be buried.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a ceramic wiring board according to the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the ceramic wiring board of the present invention. According to the ceramic wiring board 1 of FIG. 1, the insulating substrate 2 is composed of a laminated body formed by laminating a plurality of glass ceramic insulating layers 2a to 2d, and the thickness between the insulating layers and the surface of the insulating substrate is 10 to 10. A wiring circuit layer 3 made of a high-purity metal conductor having a purity of 99.5% by weight or more, particularly a metal foil, having a purity of about 15 μm and a purity of 99% or more is formed. Further, each of the glass ceramic insulating layers 2a to 2d has a diameter of 80 to 20 formed so as to penetrate in the thickness direction.
A 0 μm via-hole conductor 4 is formed, thereby forming a circuit network for connecting the wiring circuit layers 3 and achieving a predetermined circuit. The semiconductor element 5 is mounted on the surface of the wiring circuit layer 3.

In the present invention, the insulating substrate 2 is made of glass powder,
Alternatively, it is formed of a glass ceramic obtained by firing a mixture of a glass powder and a ceramic filler powder.
It is desirable that the composition be fired from a composition comprising 30 to 90% by weight of the ceramic filler component.

As the glass component used, at least
Also SiO_TwoContaining, Al_TwoO_Three, B_TwoO _Three, ZnO, Pb
O, alkaline earth metal oxides, alkali metal oxides
Containing at least one of the following,
For example, SiO_Two-B_TwoO_ThreeSystem, SiO_Two-B_TwoO_Three-Al_TwoO
_ThreeSystem, SiO_Two-B_TwoO_Three-Al_TwoO_Three-MO system (where M is
Indicates Ca, Sr, Mg, Ba or Zn. E)
Silicate glass, alkali silicate glass, Ba glass
, Pb-based glass, Bi-based glass, and the like.

These glasses are also amorphous glasses by firing, and lithium silicate, cordierite, mullite, anorthite, cellian, spinel, garnite, willemite, dolomite, petalite and the like are obtained by firing. What precipitates at least one kind of crystal of the substituted derivative is used.

Examples of the ceramic filler include SiO ₂ such as quartz glass, quartz, and cristobalite;
Al ₂ O ₃ , ZrO ₂ , mullite, forsterite, enstatite, cordierite, spinel and the like are preferably used.

In the ceramics obtained by firing the above composition, various crystal phases such as a crystal phase by a ceramic filler, a crystal phase precipitated from a glass component, and a crystal phase formed by a reaction between the glass component and the ceramic filler are included. However, the glass ceramic of the present invention is composed of a ceramic containing an amorphous component amount, in other words, a glass amount of 20% by volume or more.

As described above, in the case of a sintered glass-ceramic containing 20% by volume or more of an amorphous component, if the ceramic is fired using a porous constraining sheet as described above, the diffusion of the glass component causes the surface of the ceramic to diffuse. Causes a large amount of voids, but in the ceramic wiring board of the present invention, the void area occupancy on the outermost surface of the ceramic insulating substrate is 5% or less, particularly 3%, based on a special manufacturing method described later. It is possible to manufacture a wiring board having excellent surface properties excellent in denseness as described below.

Further, according to the present invention, the wiring circuit layer made of metal foil can be formed by using a material having a low Young's modulus of 120 GPa or less, particularly 110 GPa or less, and even 100 GPa or less of the glass ceramic forming the insulating substrate. Generation of stress due to formation can be reduced.

The Young's modulus of the glass ceramic varies depending on the material and the mixing ratio of the glass and the ceramic filler. For example, as a ceramic filler, Al ₂ O ₃ is 50% by weight because of its high Young's modulus.
With the above blending, the Young's modulus becomes larger than 120 GPa. In particular, in order to achieve a high thermal expansion and a low Young's modulus, it is desirable to contain at least one of the above-mentioned SiO ₂ , forsterite, and enstatite as a filler.

In the wiring board of the present invention, the wiring circuit layer 3
Is made of a high-purity metal conductor of 99.5% by weight or more, and is desirably made of at least one kind of metal foil selected from Cu, Ag, Al, Au, Ni, Pt, and Pd. Further, the via-hole conductor 4 is provided in the wiring circuit layer 3.
It is desirable that a conductor composed of the same components as described above is filled.

The wiring circuit layer on the surface of the ceramic wiring board is used as a pad for mounting various electronic components 5 such as an IC chip, as a shielding conductor film, and as a terminal electrode for connecting to an external circuit. Then, various electronic components 5 are joined to the wiring circuit layer 3 via solder, a conductive adhesive, or the like. Although not shown, a thick-film resistor film such as tantalum silicide or molybdenum silicide, a wiring protection film, or the like may be further formed on the surface of the wiring substrate as necessary.

Next, a method for manufacturing the ceramic wiring board of the present invention will be described. First, a glass-ceramic composition was prepared by mixing the above-mentioned inorganic filler component with the above-mentioned crystallized glass or amorphous glass, and an organic binder, a plasticizer, an organic solvent, etc. were added to the mixture to prepare a slurry. After that, it is formed into a sheet by a doctor blade method, a rolling method, a pressing method, etc., and has a thickness of about 50 to 500.
A green sheet of μm is prepared.

As the organic binder, those conventionally used for ceramic green sheets can be used. For example, acrylic binders (a homopolymer or a copolymer of acrylic acid, methacrylic acid or their esters,
Specifically, an acrylate ester copolymer, a methacrylate ester copolymer, an acrylate-methacrylate ester copolymer, etc.), a polyvinyl butyral type, a polyvinyl alcohol type, an acryl-styrene type, a polypropylene carbonate type, a cellulose type And the like.

Next, a diameter of 80 to 20 is applied to the green sheet by laser, micro drill, punching or the like.
A through hole of 0 μm is formed, and the inside thereof is filled with a conductive paste. The conductive paste is formed by homogeneously mixing an organic binder such as an acrylic resin and an organic solvent such as toluene, isopropyl alcohol, and acetone, in addition to the metal powder containing Cu or Ag as a main component. The organic binder is used in an amount of 0.5 to 100 parts by weight of the metal component.
Preferably, the organic solvent is mixed at a ratio of 5 to 100 parts by weight with respect to 100 parts by weight of the solid component and the organic binder. Note that a slight glass component or the like may be added to the conductor paste.

Next, a wiring circuit layer made of a high-purity metal conductor, particularly a metal foil, is formed on the surface of the green sheet.
A wiring circuit layer made of such a metal foil is formed by bonding a metal foil to the surface of a green sheet and then forming a desired circuit by a known method such as a photo-etching method. It is desirable to form the green sheet by a transfer method because there is a possibility that the liquid may deteriorate the quality of the green sheet.

As a method of forming a wiring circuit layer by a transfer method, first, a high-purity metal conductor, particularly a metal foil, is adhered onto a transfer film made of a polymer material or the like, and then a mirror image resist is formed on the surface of the metal conductor. After applying in a circuit pattern,
An etching process and a resist removal are performed to form a mirror image wiring circuit layer.

Then, the transfer film on which the mirror image wiring circuit layer is formed is positioned on the surface of the green sheet on which the via-hole conductor is formed and laminated and pressed, and then the transfer film is peeled off to obtain the wiring connected to the via-hole conductor. One unit of a green sheet having a circuit layer can be formed.

Thereafter, a plurality of green sheets obtained in the same manner are laminated and pressed to form a laminate. Green sheets are laminated by applying heat and pressure to the stacked green sheets and thermocompression bonding, or by applying an adhesive consisting of an organic binder, plasticizer, solvent, etc. between the sheets and thermocompression bonding. It is possible.

Next, in order to suppress shrinkage in the plane direction, a constraint sheet mainly composed of a hardly sinterable ceramic material is applied to both sides or one side of the glass ceramic green sheet laminate at the firing temperature of the green sheet laminate. A laminate is prepared by pressure lamination.

This constrained sheet is obtained by molding a slurry in which an organic binder, a plasticizer, a solvent, and the like are added to an inorganic component composed of a hardly sinterable ceramic material and glass to form a sheet. The non-sinterable ceramic material is specifically composed of a ceramic composition that does not densify at a temperature of 1000 ° C. or less, and specifically includes Al ₂ O ₃ , SiO ₂ ,
At least one type of ceramic powder selected from the group consisting of MgO, ZrO ₂ , BN, and TiO ₂ may be used. As the organic binder, plasticizer and solvent, the same materials as those used for the glass ceramic green sheet can be used.

According to the present invention, a glass component, in other words, an amorphous component, is contained in the restraining sheet in an amount of 0.5 to 15% by volume.
It is important to include. This is because the amount of glass is 0.5
If the content is less than the volume%, the restraining force of the shrinkage of the glass ceramic green sheet by the restraining sheet is small, and the diffusion of the glass component from the glass ceramic green sheet in the firing step becomes remarkable. Many voids occur. On the other hand, if the glass content is more than 15% by volume, the restraining sheet starts to sinter, which makes it difficult to restrain shrinkage of the glass ceramic green sheet, and removes the restrained sheet after sintering from the glass ceramic. This is because it becomes difficult. The amount of glass in the restraint sheet is 1 to 10% by volume
It is desirable that

The glass component contained in the constrained sheet desirably has a softening point not higher than the firing temperature of the glass-ceramic green sheet laminate and higher than the decomposition and volatilization temperature of the organic component in the constrained sheet. Specifically, the softening point of the glass in the constraint sheet is 450 to 1100.
It is preferable that the temperature is about ° C. Glass has a softening point of 450
When the temperature is lower than ℃, the softened glass when removing the organic components from the glass-ceramic green sheet blocks the removal path of the decomposed and volatilized organic components, and the organic components may not be completely removed. On the other hand, when the softening point of the glass exceeds 1100 ° C., there is a possibility that the glass ceramic green sheet does not function as a binder to the green sheet under ordinary firing conditions.

The glass component contained in the above-mentioned glass ceramic green sheet may be different from the above-mentioned glass component, or is preferably the same in order to prevent the glass of the glass ceramic green sheet from diffusing.

The thickness of the constraining sheet laminated on the glass ceramic green sheet is preferably at least 10% of the thickness of the glass ceramic green sheet laminated body on one side only. The force may decrease. Further, in consideration of the ease of volatilization of the organic component and the ease of removal of the restraint sheet from the glass ceramic substrate, the thickness of the restraint sheet is preferably 400 μm or less.

When a constraining sheet is laminated and pressed on the surface of the glass ceramic green sheet laminate, a wiring circuit layer made of a high-purity metal, particularly a metal foil, is completely embedded in the surface or the interface of the green sheet. Is desirable. This is because, due to the thickness of a highly rigid metal such as a metal foil, a gap is easily generated between the constraining sheet and the surface of the glass ceramic green sheet at the end of the wiring circuit layer. As a result, the adhesive force between the constraining sheet and the glass ceramic green sheet in the portion decreases, and the constraining force of the constraining sheet near the formation of the wiring circuit layer becomes non-uniform. As a result, the ends of the wiring circuit layer may peel off during firing. There is.

In order to embed the wiring circuit layer, it is desirable to apply a pressure of 10 MPa or more at the time of transfer to the green sheet surface or at the time of laminating the restraining sheet.
With this pressure, the wiring circuit layer made of metal foil can be forcibly buried.

Next, the laminate is subjected to heat treatment in a nitrogen atmosphere at 100 to 800 ° C., particularly 400 to 750 ° C. to decompose and remove organic components in the green sheet and the via-hole conductor paste. Co-firing in a nitrogen atmosphere. When an Ag conductor is used as the wiring circuit layer, the firing can be performed in the air. If the cooling rate after firing is too fast, cracks occur due to the difference in thermal expansion between the insulating substrate and the wiring circuit layer. Therefore, the cooling rate is desirably 400 ° C./hr or less.

During firing, a load may be applied by placing a weight on the upper surface of the laminate to prevent warpage. An appropriate load is 50 Pa to 1 MPa.

Thereafter, the constraining sheet is subjected to ultrasonic cleaning, polishing,
Water jet, chemical blast, sand blast, wet blast (method of spraying abrasive grains and water) and the like are included.

As a result, the shrinkage during firing of the obtained ceramic wiring board is suppressed only in the thickness direction by the restraint sheet, so that shrinkage in the lamination plane is reduced by 0.5%.
In addition, since the glass ceramic green sheet is uniformly and securely bonded over the entire surface by the restraining sheet, it is possible to prevent warpage or deformation due to partial peeling of the restraining sheet or the like. .

Further, according to the present invention, since the glass component on the surface of the glass ceramic green sheet can be prevented from diffusing to the constrained sheet side, the surface of the constrained sheet lamination side after firing is not insufficiently sintered. A ceramic wiring board having a good surface with a void area occupancy of 5% or less can be manufactured.

[0049]

EXAMPLE 1 The glass ceramic wiring board of the present invention is evaluated based on one example.

First, as shown in Table 1, in order to adjust the content of the amorphous component after sintering, SiO ₂ —B ₂ O ₃ —A
l ₂ O ₃ based crystallized glass or SiO ₂ -B ₂ O ₃ -Ba,
O-based amorphous glass and Al ₂ O ₃ , ZrO ₂ , and SiO ₂ as ceramic filler components were weighed to prepare glass ceramic compositions A to F in Table 1.

Using a slurry prepared by adding an acrylic resin as a binder, DBP (dibutyl phthalate) as a plasticizer, and toluene and isopropyl alcohol as a solvent, a green sheet having a thickness of 500 μm was prepared by a doctor blade method. Produced.

First, in order to measure the content of glass after sintering of the composition shown in Table 1, the composition was molded,
It baked at ℃, and produced a 10 × 10 × 3 mm test piece.
The obtained test piece was finely ground using a mortar, and the content of glass (crystallinity) was measured by the Rietveld method. Table 1 shows the measurement results.

[0053]

[Table 1]

To 100 parts by weight of the various glass ceramic compositions, 12 parts by weight of an acrylic resin, 6 parts by weight of a phthalic acid-based plasticizer, and 30 parts by weight of toluene as a solvent were added and mixed by a ball mill to prepare a slurry. The slurry was formed into a glass ceramic green sheet having a thickness of 300 μm by a doctor blade method.

Next, Cu alone having an average particle size of 5 μm, an acrylic resin as an organic binder, and dibutyl phthalate as a solvent were added and kneaded to prepare a paste-like paste sample for via-hole conductor. The amount of the organic binder in the via hole paste sample was 2.0 parts by weight based on 100 parts by weight of the main component, and a solvent was added at a ratio of 75 parts by weight based on the solid component and the organic binder. Then, via holes were formed at predetermined locations of the green sheet, and the via holes were filled with the aforementioned Cu paste.

Next, a purity of 99.9 was applied to the surface of the polymer film.
% Or more of the Cu foil was bonded and etched, and then a wiring circuit layer was formed. Although the wiring width was 0.05 mm, an extremely fine wiring circuit layer could be formed as compared with the conventional screen printing method due to the formation by etching.

Then, the transfer sheet was laminated on the green sheet on which the via-hole conductor was formed while aligning the via-hole, and thermocompression-bonded at 60 ° C. and 15 MPa. Thereafter, by peeling off the transfer sheet, a single wiring layer having a wiring circuit layer to which via-hole conductors were connected could be formed.

Similarly, five wiring layers are formed,
These were laminated to form a glass ceramic green sheet laminate.

Next, as a restraining sheet, a purity of 99.99 was used.
% Alumina was added using the same glass as the glass component in the green sheet, to produce a 250 μm-thick restraint sheet made of various compositions shown in Table 2. Note that the organic binder, plasticizer, solvent, and the like during sheet production were exactly the same as for the green sheet.

[0060]

[Table 2]

The obtained constrained sheet was pressed against both sides of the green sheet laminate 1 at 60 ° C. and a pressure of 20 MPa to obtain a laminate.

Next, this laminate is placed on an Al ₂ O ₃ setter and fired at 700 ° C. in a nitrogen atmosphere to decompose and remove organic components such as an organic binder. The firing was performed at 900 ° C. for 1 hour. Thereafter, the constraining sheet was removed by blasting to produce a wiring board.

The external appearance of the wiring board was observed, and the presence or absence of deformation / adhesion was confirmed. The surface state of the wiring board was observed with a scanning electron microscope photograph, and the void area occupancy was determined by image analysis.

The conduction resistance of the wiring layer was evaluated using the obtained wiring board. About evaluation, width 0.05
A copper wiring layer having a thickness of 20 mm and a length of 20 mm is formed in advance, the wiring resistance is measured using a tester, and the cross section of the copper wiring layer is measured using a scanning electron microscope (SEM) and a microscope having a copper wiring length of 40 times. The resistivity was calculated from the obtained area and length. In addition, as for the judgment of pass / fail, the resistivity is 2.5 μΩ · c
m or less was defined as a good product.

Further, the shrinkage rate was calculated by measuring the outer edge of the insulating substrate before firing, with a micrometer, and measuring the outer edge after firing with a micrometer.

Examples 2, 3, and 4 The substrate materials were the same as in Example 1, and the conductor materials were Ag and Ag.
Using / Pd and Ag / Pt, a wiring board was manufactured in the same specifications as in Example 1. The firing was performed at 900 ° C. in the air. Table 3 shows the evaluation results.

Examples 5, 6, and 7 The restraining sheets were made of SiO ₂ , Mg, and
Evaluation was made as O and ZrO ₂ . Table 3 shows the evaluation results.

Comparative Example 1 The same specifications as in Example 1 were used, and the conductor was formed by a conventional screen printing method from the transfer of a metal foil. Since the wiring width was as fine as 0.05 mm, disconnection occurred. Table 3 shows the evaluation results.

[0069]

[Table 3]

Table 3 shows that the glass content of the substrate material was 2
Sample No. less than 0% by volume. Sample No. 1 in which the amount of glass in the restraint sheet was less than 0.5% by volume. In No. 7, since the restraint sheet was peeled off during firing, firing shrinkage occurred,
The state of the substrate surface was also rough, and the void ratio was larger than 5%.

The glass content of the restraint sheet is 15% by volume.
Sample no. In No. 14, the constraining sheet adhered badly and was difficult to peel off. In the comparative example, the sample No. in which the wiring circuit layer was formed by the screen printing method was used. 2
In No. 1, disconnection occurred. In the other samples using the metal foil, a good wiring circuit layer could be formed without any problem.

[0072]

As described in detail above, according to the present invention,
A ceramic circuit board having a wiring circuit layer made of a low-resistance metal such as Cu or Ag, capable of stably controlling shrinkage in a planar direction, enabling fine wiring, and having a good surface condition of the board. Obtainable.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view for explaining an example of a ceramic wiring board of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic wiring board 2 Insulating board 2a-2d Insulating layer 3 Wiring circuit layer 4 Via-hole conductor 5 Semiconductor element

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H05K 3/46 C04B 35/00 J F term (Reference) 4E351 AA07 AA12 BB30 BB49 CC17 DD01 DD04 DD05 DD06 DD10 DD19 DD20 DD54 GG11 4G030 AA07 AA08 AA10 AA17 AA32 AA35 AA36 AA37 CA08 GA14 GA15 GA20 PA21 5E346 AA12 AA15 AA24 AA38 AA43 BB01 CC18 CC31 CC32 CC39 CC60 DD02 DD12 DD33 EE24 EE25 EE29 FF18 GG03 HGG08

Claims (8)

[Claims] 1. The surface of an insulating substrate made of glass ceramics and containing at least 20% by volume of an amorphous component and / or
Alternatively, a wiring board in which a wiring circuit layer made of a high-purity metal conductor having a metal component content of 99.5% by weight or more is formed, wherein the void area occupation ratio on the outermost surface of the insulating substrate is 5%. % Or less. 2. The ceramic wiring board according to claim 1, wherein said wiring circuit layer is made of a metal foil. 3. The circuit board according to claim 2, wherein the wiring circuit layer made of the metal foil is embedded in a surface of the insulating substrate.
The ceramic wiring board as described. (A) the content of the amorphous component after firing is 20;
And (b) forming a wiring circuit layer comprising a high-purity metal conductor having a metal component content of 99.5% by weight or more on the surface of the green sheet. Forming (c)
Laminating a green sheet on which the wiring circuit layer is formed; and (d) at least one surface of the green sheet laminated body contains a non-sinterable ceramic material as a main component,
And a step of laminating a restraint sheet containing 0.5 to 15% by volume of an amorphous component, and (e) firing a laminate of the restraint sheet and the green sheet laminate to hold the restraint sheet on the surface. Producing a glass ceramic substrate;
(F) removing the restraining sheet from the glass ceramic substrate. 5. The method according to claim 4, wherein the high-purity metal conductor having a metal component content of 99.5% by weight or more is made of a metal foil. 6. The hard-to-sinter ceramic material is Al
_{2 O 3, SiO 2, MgO} , ZrO 2, BN, 4. a manufacturing method of a ceramic wiring board, wherein a composed mainly of at least one selected from the group consisting of TiO _2. 7. The method according to claim 5, wherein in the step (d), the wiring circuit layer made of the metal foil is embedded in a surface of the green sheet. 8. The method according to claim 4, wherein the softening point of the amorphous component contained in the constraining sheet is lower than the firing temperature of the glass ceramic composition.