JP2002198646A - Method of manufacturing multilayer wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a multilayer wiring board which can prevent the warp and deformation of a wiring board and can effectively suppress the lateral shrinkage of a constraint sheet. SOLUTION: The method of manufacturing a multilayer wiring board comprises a process of forming a wiring circuit layer 3 on the surface of a green sheet 1 containing ceramic powder comprising silicon oxide powder and glass powder, and then laminating a plurality of the green sheets 1 to form a laminate; a process of laminating the constraint sheet 8 containing forsterite and amorphous components on at least one surface of the laminate to form a molded body; a process of baking the molded body at a melting point or lower of the wiring circuit layer 3; and a process of removing the constraint sheet 8 formed on the surface.

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

[0002]

2. Description of the Related Art Conventionally, a multilayer ceramic wiring board capable of relatively high-density wiring has been frequently used as a wiring board, for example, a multilayer wiring board used for a package for housing a semiconductor element. This multilayer ceramic wiring board is composed of an insulating substrate such as alumina or glass ceramic, and a wiring conductor formed on the surface thereof and made of a metal such as W, Mo, Cu, or Ag. A cavity is formed in a part, a semiconductor element is housed in the cavity, and the cavity is hermetically sealed by a lid.

In recent years, high-density packaging has been required for semiconductor element storage packages for mounting semiconductor elements such as ICs and LSIs, and for hybrid integrated circuit devices on which various electronic components are mounted. , Low resistance, small size and light weight are required, a low dielectric constant is obtained as compared with the alumina-based ceramic material, a low-resistance metal such as Cu can be used for the wiring circuit layer, and the firing temperature is 1000 A so-called glass ceramic wiring substrate having a temperature of less than or equal to ° C. has been receiving more attention.

In such a glass-ceramic wiring board, a constraining sheet made of a layer of an inorganic composition which is not sintered at the firing temperature of the glass-ceramic green sheet is formed on both sides of the glass-ceramic green sheet on which the wiring circuit layer is formed. Then, simultaneous firing, restraint sheet and glass ceramic green sheet are restrained by frictional force,
Japanese Patent Laying-Open No. 7-86743 proposes a method that enables simultaneous firing of a metal foil and a glass ceramic by suppressing firing shrinkage in the planar direction of a glass ceramic green sheet.

[0005] Further, glass that does not crystallize at the firing temperature of the glass ceramic insulating substrate is laminated on both sides of the glass ceramic green sheet on which the wiring circuit layer is formed to form a constrained sheet. Japanese Patent Application Laid-Open No. H10-75060 describes that it can be removed.

[0006]

However, according to the method disclosed in Japanese Patent Application Laid-Open No. Hei 7-86743, the glass ceramic insulating substrate is restrained only by the frictional force and the shrinkage is suppressed. In particular, a thermal expansion coefficient of 8 × 10 ⁻⁶ / ° C. or more, which has recently attracted attention in reducing the average thermal expansion coefficient difference from an external circuit board such as a printed circuit board to enhance mounting reliability, has been noted. 15x
In the case of a glass-ceramic wiring board of 10 ⁻⁶ / ° C., especially 9 × 10 ⁻⁶ / ° C. to 15 × 10 ⁻⁶ / ° C., it becomes difficult to restrain shrinkage only by frictional force, and the restraining sheet is made of glass ceramic insulating substrate. There were problems such as peeling, warpage and deformation.

Further, the method described in JP-A-10-75060 has a problem that even if glass is used as a restraining sheet, it does not react with the green sheet and does not exhibit sufficient restraining force.

Accordingly, it is an object of the present invention to provide a method of manufacturing a multilayer wiring board which is free from warpage or deformation and can effectively suppress shrinkage of a restraint sheet in a planar direction.

[0009]

SUMMARY OF THE INVENTION According to the present invention, the shrinkage of the green sheet is caused by causing the silicon oxide powder contained in the green sheet to react with the forsterite contained in the restraint sheet to bring the green sheet and the restraint sheet into close contact. Can be effectively suppressed.

That is, after forming a wiring circuit layer on the surface of a green sheet containing a ceramic powder containing a silicon oxide powder and a glass powder, a plurality of the green sheets are laminated to form a laminate. A step of laminating a constraining sheet containing forsterite and an amorphous component on at least one surface to form a molded body, and firing the molded body at a temperature equal to or lower than the melting point of the wiring circuit layer, Removing the restraint sheet on the surface.

In particular, it is preferable to form a reaction product between silicon oxide of the green sheet and forsterite of the constrained sheet between the ceramic green sheet and the constrained sheet during firing. Further, it is preferable that the reactant is an enstatite crystal phase. Accordingly, the binding between the restraint sheet and the green sheet is strengthened, and the restraint sheet can sufficiently suppress the shrinkage of the green sheet.

It is preferable that the restraining sheet further contains alumina and / or silicon oxide. By containing alumina and silicon oxide, the coefficient of thermal expansion of the restraint sheet can be adjusted, and alumina has the effect of improving the adhesion to the green sheet. Further, by adding silicon oxide, the adhesiveness to the glass ceramic substrate during firing can be further improved.

[0013] Further, the restraining sheet is 25-99.
5% by volume forsterite, 0 to 40% by volume silicon oxide, 0 to 60% by volume alumina and 0.5 to 15% by volume
Of an amorphous component of By controlling the composition within this range, it is possible to stably suppress shrinkage in the planar direction.

Further, it is preferable that the softening point of the amorphous component contained in the restraint sheet is lower than the firing temperature. By setting the firing temperature at or above this softening point, the adhesion of the green sheet to the glass component can be further increased.

Further, the average thermal expansion coefficient difference between the green sheet and the restraint sheet at 40 to 400 ° C. is 3 ×
It is preferably at most 10 ⁻⁶ / ° C. Thereby, generation of cracks due to a difference in thermal expansion during cooling can be suppressed.

Further, it is preferable that the filling rate of the powder before firing the constraining sheet is 51 to 63% in relative density. Thereby, the restraint by the restraint sheet is improved, and the shrinkage of the glass ceramic insulating substrate in the planar direction can be effectively suppressed.

Furthermore, it is preferable that the wiring circuit layer is made of a metal foil, and in particular, is made of at least one selected from Cu, Ag, Au, Ni, Pt, and Pd. This is because the electric resistance is low and simultaneous firing with glass ceramic is possible.

It is preferable that the wiring circuit layer made of the metal foil is buried from the surface of the green sheet to the inside. This is to prevent separation between layers when laminating the respective green sheets.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for manufacturing a multilayer wiring board according to the present invention will be described with reference to a process chart showing an example of a method for manufacturing a multilayer wiring board according to the present invention in FIG.

First, glass powder and ceramic powder are prepared as raw material powders for the green sheet. For example, a glass powder having an average particle size of 0.5 to 10 μm, particularly 1 to 5 μm, and an average particle size of 0.5 to 10 μm, particularly 1 to 5 μm
Prepare a 5 μm ceramic powder.

As the glass powder, at least a silicon oxide (SiO ₂ ) component, Al ₂ O ₃ , B ₂ O ₃ , ZnO, Pb
O, an alkaline earth metal oxide, a glass powder containing at least one of alkali metal oxides, for example,
SiO ₂ -B ₂ O _{3 based, SiO 2 -B 2 O 3 -Al} 2 O 3 -MO
Borosilicate glass, alkali silicate glass, Ba, and the like (where M represents Ca, Sr, Mg, Ba or Zn)
System glass, Pb system glass, Bi system glass and the like.

These glasses remain as amorphous glass even after firing, or are subjected to alkali metal silicate, quartz, cristobalite,
What precipitates at least one kind of crystal of cordierite, mullite, enstatite, anorthite, sergian, spinel, garnite, diopside, ilmenite, willemite, dolomite, petalite or a substituted derivative thereof is used.

It is important that the ceramic powder contains at least SiO ₂ powder such as quartz and cristobalite. In addition to this, alumina powder, zirconia powder, mullite powder, forsterite powder, enstatite powder, spinel powder And at least one selected from the group consisting of magnesia powder.

The above glass powder and ceramic powder are
For example, 10 to 90% by volume of glass powder, especially 50 to 80%
% By volume and 10 to 90% by volume of ceramic powder, in particular 20
Mix at a rate of ５０50% by volume. After adding an organic binder or the like to the mixture, the mixture is formed into a sheet by a doctor blade method, a rolling method, a pressing method, or the like, and has a thickness of about 50 to 50.
A green sheet 1 of 0 μm is prepared.

Next, the green sheet 1 has a diameter of 80 to 2 by laser, micro drill, punching or the like.
A via hole conductor 2 is formed as shown in FIG. 1A by forming a through hole of 00 μm and filling the inside with a conductive paste.

This conductor paste is used to match the metal components such as Cu and Ag, an organic binder such as an acrylic resin, an organic solvent such as toluene, isopropyl alcohol and acetone, and the firing shrinkage behavior of the green sheet. It is formed by mixing a fixed amount of ceramic powder.

The organic binder is mixed at a ratio of 0.5 to 15.0 parts by weight with respect to 100 parts by weight of the metal and the ceramic component, and 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. It is desirable to be done. In addition, it is desirable to add 6 to 40 parts by weight of the ceramic powder (silicon oxide, alumina, glass, etc.) to 100 parts by weight of the metal component from the viewpoint of matching the firing shrinkage behavior of the green sheet.

Next, a wiring circuit layer 3 is formed on the surface of the green sheet 1. The wiring circuit layer 3 can be formed by a printing method or the like using a conductor paste containing a metal conductor powder for forming the via-hole conductor 2 described above, but in particular, the width of the wiring circuit layer 3 is 75 μm or less, In particular, 50 μm or less, and the pitch of the wiring circuit layer 3 is 150 μm.
m or less, especially 100 μm or less,
It is desirable to use metal foil. Examples of the metal foil include Cu, Ag, Au, Ni, and P having a purity of 99% by weight or more.
It is desirable that the material be made of at least one high-purity metal selected from the group consisting of t and Pd.

The wiring circuit layer 3 made of such a metal foil
It is known that a method of forming a desired circuit by a method such as a well-known photo-etching method after bonding a metal foil to a surface of a green sheet is known. However, such a method involves altering the green sheet by an etching solution. ,
It is desirable to form by a transfer method.

As a method of forming the wiring circuit layer 3 by the transfer method, first, a high-purity metal conductor, particularly a metal foil, is bonded onto a transfer film 5 made of a polymer material, and a mirror image resist is formed on the surface of the metal conductor. Is preferably applied in the form of a circuit pattern, followed by etching and resist removal.

Then, as shown in FIG. 1B, after the transfer film 5 on which the wiring circuit layer 3 of the mirror image is formed is aligned with the surface of the green sheet 1 on which the via-hole conductor 2 is formed and laminated and pressed. By peeling off the transfer film 5, one unit of the green sheet 1 including the wiring circuit layer 3 to which the via-hole conductor 2 is connected can be formed.

When the transfer film 5 is laminated and pressure-bonded to the surface of the green sheet 1, for example, the wiring circuit layer (metal foil) 3 is thermally pressed at 50 to 80 ° C. under a pressure of 10 to 20 MPa to form the wiring circuit layer (metal foil) 3 on the green sheet. It is desirable to buried the green sheet 1 from the surface into the inside of the substrate.
It is possible to prevent the occurrence of peeling or cracking at the interface due to the difference in thermal expansion between 0 and the wiring circuit layer (metal foil) 3 and the difference in thermal expansion between the constraint sheet 8 and the wiring circuit layer 3 described below. Also, due to the thickness of the highly rigid wiring circuit layer 3 made of a metal foil, a gap is generated at the interface between the constraint sheet 8 and the green sheet 1 at the end of the wiring circuit layer 3, and the constraint sheet 8 and the green sheet 1 at that portion are formed. As a result, the end of the wiring circuit layer 3 can be prevented from peeling off during firing.

As the wiring circuit layer 3, a wiring circuit layer 6 occupying 50% or more of the area of the green sheet surface, such as a ground layer for transmitting a high-frequency signal, is shown in FIG. In particular, the thermal expansion coefficient of the main component metal of the wiring circuit layer 6 is, for example, 16 to
When the temperature is as high as 17 × 10 ⁻⁶ / ° C., the above-described conductor paste is used to prevent peeling and cracking due to a difference in average thermal expansion coefficient between the wiring circuit layer 6 and the glass ceramic insulating substrate 10 and the restraining sheet 8. It is desirable to form by a printing method by using.

Thereafter, a plurality of green sheets 1a to 1d obtained in the same manner are laminated and pressed to form a laminate.
For laminating the green sheets 1, a method of applying heat and pressure to the stacked green sheets 1 to perform thermocompression bonding, a method of applying an adhesive made of an organic binder, a plasticizer, a solvent, or the like between the sheets and performing thermocompression bonding, etc. Can be adopted.

Next, a raw material powder for the restraint sheet 8 is prepared. For example, a glass powder having an average particle size of 0.5 to 10 μm, particularly 1 to 5 μm, and an average particle size of 0.5 to 10 μm
m, especially a forsterite powder having an average particle size of 1 to 5 μm, and optionally an alumina powder having an average particle size of 0.5 to 10 μm, especially an average particle size of 1 to 5 μm and / or an average particle size of 0.5.
A silicon oxide powder having an average particle size of 1 to 5 μm is prepared.

The glass powder contains at least a silicon oxide (SiO ₂ ) component, and includes Al ₂ O ₃ , B ₂ O ₃ , ZnO,
It contains at least one of PbO, alkaline earth metal oxides and alkali metal oxides, for example, SiO ₂ —B ₂ O ₃ , SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ −
MO type (where M is Ca, Sr, Mg, Ba or Zn
Borosilicate glass, alkali silicate glass, etc.
Ba-based glass, Pb-based glass, Bi-based glass, and the like can be given. This glass powder may be different from the glass powder contained in the green sheet 1, but it is desirable to use the same glass in order to prevent the glass in the green sheet 1 from diffusing.

After adding an organic binder or the like to the mixture, the mixture is formed into a sheet by a doctor blade method, a rolling method, a pressing method, or the like, to produce a green sheet 1 having a thickness of about 50 to 500 μm.

According to the present invention, the constraining sheet 8 shown in FIG. 1D is composed of 25 to 99.5% by volume of forsterite, 0.5 to 15% by volume of an amorphous component, and 0 to 40% by volume of SiO _2. %, And Al ₂ O ₃ is preferably 0 to 60% by volume. By setting such a composition range, the effect of more stably suppressing shrinkage in the planar direction can be obtained, and FIG.
Is obtained.

The composition of the green sheet 1 was adjusted.
The average thermal expansion coefficient difference (hereinafter simply referred to as the average thermal expansion coefficient difference) between 40 ° C. and 400 ° C. between the glass ceramic insulating substrate 10 and the restraint sheet 8 obtained by baking the above is 3 × 10 ⁻⁶ / ° C.
^Or less, especially 2 × 10 ⁻⁶ / ° C. or less, further 1 × 10 ⁻⁶ / ° C.
° C or less, and thereby, it is possible to prevent cracks or peeling occurring near the bonding surface of the constraining sheet 8 of the glass ceramic insulating substrate 10 during cooling after firing, or cracks occurring in the glass ceramic insulating substrate 10. it can.

In particular, the thermal expansion coefficient of the constraining sheet is adjusted to 8 to 15 × 10 ⁻⁶ / by adjusting the addition amounts of silicon oxide and alumina.
The temperature can be controlled in the range of ° C. to easily match the coefficient of thermal expansion with the green sheet.

Further, the filling rate of the powder before baking the constraining sheet 8 is represented by a relative density and is preferably 51 to 63%. By increasing the relative density, the adhesion between the constrained sheet 8 and the green sheet laminate in the raw stage is improved, so that the shrinkage of the glass ceramic insulating substrate 10 in the plane direction can be effectively suppressed.

Next, the restraining sheet 8 is replaced with the green sheet 1a.
To 1d are laminated under pressure on at least one surface of the laminate to produce a laminate. Thereby, it is possible to suppress the green sheet from shrinking in the plane direction during firing. In order to effectively suppress shrinkage, it is preferable that the constraining sheet be laminated on both surfaces of the laminate of the green sheets 1a to 1d whose main component is a ceramic material that is difficult to sinter at the firing temperature.

In the present invention, as the glass ceramic insulating substrate 10, the thermal expansion coefficient of the glass ceramic insulating substrate 10 is reduced in order to reduce the average thermal expansion coefficient difference from an external circuit substrate such as a printed circuit board and improve the mounting reliability. The coefficient is 8 ×
It is preferably at least 10 ⁻⁶ / ° C., particularly preferably 9 to 15 × 10 ⁻⁶ / ° C.

In order to reduce the firing shrinkage on the surface (principal plane) of the glass ceramic insulating substrate 10, the thermal expansion coefficient of the restraining sheet 8 is limited to the glass ceramic insulating substrate 1.
It is desirable that the thermal expansion coefficient of the constraining sheet 8 is not less than the thermal expansion coefficient of the glass ceramic insulating substrate 10 in that the tensile stress due to the difference in thermal expansion does not remain in the glass ceramic insulating substrate 10. It is desirable that In particular, it is desirable that the thermal expansion coefficient of the constraining sheet 8 be equal to or less than the thermal expansion coefficient of the glass ceramic insulating substrate 10.

The constraining sheet 8 is made of a non-sinterable ceramic material as a main component, and is formed into a sheet-like slurry by adding an organic binder, a plasticizer, a solvent, etc. to an inorganic component containing 0.5 to 15% by weight of glass. Obtained by molding. The non-sinterable ceramic material is specifically composed of a ceramic composition that does not densify at a temperature of 1000 ° C. or less,
Specifically, the average particle size is 0.5 to 10 μm, particularly 1 to 5 μm
Al ₂ O ₃ , SiO ₂ , forsterite (Mg ₂ SiO
₄ ) powder. It is important that the forsterite is contained in the constraining sheet 8 in an amount of 25 to 99.5% by volume in order to increase the adhesion by reacting with the SiO ₂ powder in the green sheet. Preferably, it is contained by volume.

As the organic binder, plasticizer and solvent, the same materials as those used to form the green sheet made of glass ceramic, specifically, an acrylic binder, a plasticizer such as DBP, and a solvent such as IPA, acetone and toluene are used. Etc. can be suitably used.

According to the present invention, it is important that the constraining sheet 8 contains a glass component, that is, an amorphous component in an amount of 0.5 to 15% by volume. This is because the amorphous component is 0.
If the content is less than 5% by volume, the restraining force of the shrinkage of the green sheet 1 by the restraining sheet 8 is small, and the glass component from the green sheet 1 diffuses and moves toward the restraining sheet 8 by the capillary phenomenon in the firing step. As a result, many voids are generated on the surface of the glass ceramic insulating substrate 10 after sintering. If the amorphous component is more than 15% by volume, sintering of the restraining sheet 8 itself starts and shrinks due to sintering. As a result, it becomes difficult to suppress shrinkage of the green sheet 1 and sintering occurs. After, restraint sheet 8
Is difficult to remove from the glass ceramic insulating substrate 10. The preferred glass amount of the restraining sheet 8 is 1 to 12% by volume, and the most preferred range is 3 to 10% by volume.

As the glass component contained in the restraining sheet 8, in order to easily remove the organic component from the green sheet 1 and to enhance the adhesion between the glass ceramic insulating substrate 10 and the restraining sheet 8, It is desirable that the softening point be equal to or lower than the firing temperature of the laminate of the green sheets 1a to 1d and higher than the decomposition and volatilization temperature of the organic component in the constraining sheet 8. Specifically, the softening point of the glass in the constraint sheet 8 is preferably about 450 to 1100 ° C.
Further, the glass is desirably a powder of 0.5 to 10 μm.

The thickness of the constraining sheet 8 laminated on the laminate of the green sheets 1a to 1d increases the constraining force, facilitates the volatilization of organic components, and improves the removability of the constraining sheet 8 from the glass ceramic insulating substrate 10. Considering the thickness of the laminate of the green sheets 1a to 1d,
00%, especially 30-150%, even 50-100%
It is good to be. The thickness of the restraint sheet 8 is
It indicates the thickness of the constraint sheet 8 laminated on one surface.

Next, the laminate was heated in an oxidizing or weakly oxidizing atmosphere at 100 to 850 ° C., particularly 400 to 750 ° C., to decompose and remove organic components in the green sheet 1 and the via-hole conductor paste. Later, 800-1100
Co-firing in an oxidizing or non-oxidizing atmosphere at ℃. When a conductor that is not oxidized by heat treatment such as a Cu conductor is used as the wiring circuit layer, the firing must be performed in a non-oxidizing atmosphere. When a conductor that is not oxidized by the heat treatment such as an Ag conductor is used as the wiring circuit layer, firing is performed. The atmosphere can be performed in an oxidizing atmosphere such as the air.

If the cooling rate after the firing in this firing is too fast, cracks occur due to the temperature difference and the thermal expansion difference between the insulating substrate 10, the wiring circuit layer 3, and the restraint sheet 8, so that the cooling rate is 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, if desired, the constraining sheet 8 is removed by ultrasonic cleaning, polishing, water jet, chemical blast, drive blast, wet blast or the like, whereby the multilayer wiring board A of the present invention can be manufactured.

The multilayer wiring board A obtained by the above method
Since the shrinkage during firing is suppressed only in the thickness direction by the constraint sheet 8, the shrinkage in the plane of the laminate is reduced, for example, when the laminate has a rectangular shape, the contraction rate of the length of one side is reduced. 0.5% or less, and since the green sheet 1 is uniformly and securely bonded over the entire surface by the restraining sheet 8, warpage or deformation due to partial peeling of the restraining sheet 8 or the like is prevented. Can be prevented.

It is preferable that the silicon oxide contained in the green sheet 1 and the forsterite contained in the constrained sheet 8 react between the green sheet 1 and the constrained sheet 8 during firing to form a reactant. It is particularly preferred that this reaction product is in the enstatite crystal phase. As described above, by forming a reactant such as enstatite between the green sheet 1 and the restraining sheet 8, the bonding force between the green sheet 1 and the restraining sheet 8 can be increased, and the surface direction of the green sheet can be enhanced. The contraction sheet efficiently suppresses shrinkage, and a shrinkage ratio of 0 is also possible.

Therefore, according to the present invention, a glass ceramic having a wiring circuit layer formed on the surface and / or inside thereof, a constraining sheet containing forsterite provided on at least the main surface of the glass ceramic, and A sintered body including a constraining sheet and a reaction layer such as an enstatite crystal phase formed between the glass ceramics is obtained, and a multilayer wiring board can be manufactured by removing the constraining sheet and a reactant. .

For example, as shown in FIG.
Is composed of a laminated body formed by laminating a plurality of glass ceramic insulating layers 10a to 10d having a thickness of 50 to 250 μm, and a high thickness of about 9 to 18 μm is formed between the insulating layers 10a to 10d and on the surface of the insulating substrate 10. A wiring circuit layer 3 made of a pure metal foil is adhered and formed. Further, a via-hole conductor 2 having a diameter of 80 to 200 μm is formed so as to penetrate through the thickness direction of each of the glass ceramic insulating layers 10 a to 10 d, thereby connecting the wiring circuit layers 3 to achieve a predetermined circuit. Is formed. An electronic component B such as a semiconductor element is mounted and mounted on the surface of the wiring circuit layer 3.

In FIG. 2, the wiring circuit layer 3 on the surface
Are used as pads for mounting various electronic components B such as IC chips, as conductive films for shielding, and as terminal electrodes for connection to external circuits.
Are bonded 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 multilayer wiring board A as necessary.

Further, in FIG. 2, the insulating layers 10a to 10a
A wiring circuit layer 3 serving as a ground layer formed by printing the above-described conductor paste is formed inside 10d.

[0060]

EXAMPLES First, glass and ceramics shown in Table 1 were weighed, and an acrylic resin was used as a binder, DBP (dibutyl phthalate) was used as a plasticizer, and toluene and isopropyl alcohol were used as a solvent. And a thickness of 50 by the doctor blade method.
A 0 μm green sheet was produced. Table 1 shows the firing conditions of the green sheet described below (in nitrogen, 950
C. for 1 hour) shows the coefficient of thermal expansion of glass ceramics obtained by firing at 40 to 400 ° C.

Next, Cu powder having an average particle size of 5 μm, Au
8 wt% of SiO ₂ powder as a filler component with respect to the powder, Ni powder, Pt powder, Pd powder and Ag powder,
To these inorganic components, 2 parts by weight of an acrylic resin as an organic binder and 75 parts by weight of acetone as a solvent were added and kneaded to prepare a paste-like via-hole conductor paste. Then, a via hole was formed at a predetermined position of the green sheet, and the via hole paste was filled in the via hole.

On the other hand, the polymer film has a purity of 99.5%
The metal foils shown in Table 1 above were adhered and etched to form a wiring circuit layer, thereby producing a transfer sheet. The wiring width was 50 μm, and the wiring layer pitch was 100 μm.

Then, an adhesive composed of the organic component used for forming the green sheet is applied to the surface of the transfer sheet on which the wiring circuit layer is formed by screen printing, and then the via sheet is aligned with the position of the via hole on the green sheet where the via hole is formed. While laminating the transfer sheet, 60 ℃,
The wiring circuit layer was embedded from the surface of the green sheet to the inside by thermocompression bonding at 15 MPa. Thereafter, the transfer sheet was peeled off to form a unit wiring layer having a wiring circuit layer to which the via-hole conductor was connected. Also, five sheets of any one of these green sheets were laminated to form a laminate.

On the other hand, at least one of a forsterite powder having an average particle diameter of 2 μm, a glass powder having an average particle diameter of 5 μm, and, if desired, at least one of SiO ₂ powder and Al ₂ O _{3 having} an average particle diameter of 3 μm has the composition shown in Table 1. Mixed, thickness 250μ
m restraint sheet was produced. The filling rate of the restraint sheet was calculated from the size and weight, the density was divided by the theoretical density, the relative density was calculated, and this was defined as the filling rate.

The organic binder, plasticizer, solvent and the like used in the preparation of the sheet were the same as those of the green sheet, and the average thermal expansion coefficient at 40 to 400 ° C. after firing described later is shown in Table 1. This constrained sheet was laminated under pressure at 60 ° C. and 20 MPa on both sides of the green sheet laminate to obtain a laminate.

Next, this laminate was placed on an Al ₂ O ₃ setter and heated to 700 ° C. in a steam-containing nitrogen atmosphere to decompose and remove organic components such as an organic binder.
Further, firing was performed in a nitrogen atmosphere. The firing temperatures are shown in Table 1. The cooling rate after firing was 300 ° C./hr.
After that, the constraining sheet was removed by blasting to produce a multilayer wiring board.

The appearance of the obtained multilayer wiring board was observed, and the presence or absence of deformation and cracks was confirmed. The conduction resistance of the wiring circuit layer was evaluated using this multilayer wiring board. For evaluation, a wiring circuit layer made of copper foil (width 5
0 μm), the wiring resistance was measured with a tester, the cross section of the wiring circuit layer was measured using a scanning electron microscope (SEM), and the length of the copper wiring was measured using a microscope. The specific resistance was calculated from the shape.

Further, the shrinkage rate of the glass ceramic insulating substrate due to firing was measured by measuring the length of one side before and after firing of the insulating substrate (l ₁ , l ₂ ), and the shrinking rate ((l ₁ -l ₂ ) / l ₁ x 10
0%) was calculated. The results are shown in Table 1.

[0069]

[Table 1]

Sample No. of the present invention Nos. 2 to 5, 7 to 13 and 15 to 26 have no cracks or peeling, no deformation, a shrinkage ratio of the glass ceramic insulating substrate of 0.5% or less, and a wiring circuit layer of 2.2 μΩ · cm or less. It had the characteristic which was.

On the other hand, the sample No. 1 in which the silicon oxide powder was not included in the ceramic powder in the green sheet was used. No. 1 and sample N which does not include forsterite in the restraining sheet and is outside the scope of the present invention
o. In No. 6, a crack occurred and the wiring was disconnected.

Further, Sample No. which does not contain an amorphous component in the restraining sheet and is out of the range of the present invention. In No. 14, peeling occurred because the binding force was weak.

[0073]

According to the present invention, the shrinkage of the glass-ceramic insulating substrate in the plane direction due to the restraint sheet can be effectively suppressed by including the silicon oxide powder in the green sheet and the forsterite in the restraint sheet. it can.

[Brief description of the drawings]

FIG. 1 is a process chart for explaining a method for manufacturing a multilayer wiring board of the present invention.

FIG. 2 is a schematic sectional view of a multilayer wiring board obtained by a method for manufacturing a multilayer wiring board of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Green sheet 2 ... Via-hole conductor 3, 6 ... Wiring circuit layer 5 ... Transfer film 8 ... Restriction sheet 10 ... Glass ceramic insulating substrate A ... Multilayer wiring board B. ..Electronic components

Claims (11)

[Claims] 1. A step of forming a wiring circuit layer on the surface of a green sheet containing glass powder and ceramic powder containing silicon oxide powder, and then laminating a plurality of the green sheets to form a laminate. A step of laminating a constraining sheet containing forsterite and an amorphous component on at least one surface of the body to form a molded body, and firing the molded body at a temperature equal to or lower than the melting point of the wiring circuit layer. Removing the constraining sheet on the surface. 2. A method for manufacturing a multilayer wiring board according to claim 1, wherein a reaction product of silicon oxide of the green sheet and forsterite of the restraint sheet is formed between the green sheet and the restraint sheet during firing. . 3. The method according to claim 2, wherein the reactant is an enstatite crystal phase. 4. The constraining sheet further comprises alumina and / or
4. The method for manufacturing a multilayer wiring board according to claim 1, further comprising silicon oxide. 5. The restraint sheet according to claim 5, wherein the content is 25 to 99.5% by volume.
Forsterite, 0-40 volume% silicon oxide, 0
5. The method according to claim 1, comprising 60% by volume of alumina and 0.5% to 15% by volume of an amorphous component. 6. The method for manufacturing a multilayer wiring board according to claim 1, wherein the softening point of the amorphous component contained in the constraining sheet is equal to or lower than a firing temperature. 7. An average thermal expansion coefficient difference between the green sheet after firing and the constrained sheet at 40 to 400 ° C.
The method according to any one of claims 1 to ^{6, wherein the} temperature is not higher than ^10-6 / C. 8. The method for manufacturing a multilayer wiring board according to claim 1, wherein a filling rate of the powder before firing the restraining sheet is 51 to 63% in relative density. 9. The method according to claim 1, wherein said wiring circuit layer is made of a metal foil. 10. The method according to claim 1, wherein the metal foil is made of Cu, Ag, Au, Ni,
The method for manufacturing a multilayer wiring board according to claim 9, comprising at least one selected from Pt and Pd. 11. The method for manufacturing a multilayer wiring board according to claim 9, wherein the wiring circuit layer made of the metal foil is buried inside from the surface of the green sheet.