JP2003078245A - Method for manufacturing multilayer wiring board - Google Patents

Abstract

(57) [Problem] To produce cracks, delaminations, etc. in an insulating substrate when manufacturing a wiring substrate formed by using a glass ceramic as an insulating substrate and forming a wiring circuit layer made of metal foil on the surface thereof. And stably controls shrinkage in the planar direction. A wiring circuit layer made of metal foil is provided on a surface of a green sheet containing glass powder and inorganic filler powder.
In a method of manufacturing a multilayer wiring board, a green sheet 1 is formed by stacking a plurality of green sheets 1 and firing the stacked body at a temperature equal to or lower than the melting point of the wiring circuit layer 3 while suppressing shrinkage in a planar direction. The rate and the type and amount of the organic binder are adjusted, and the tensile strength of the green sheet based on JIS K6251 is set to 2000 to 5000 KPa.

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, a multilayer wiring board suitable for a package for housing a semiconductor element, and the like.

[0002]

2. Description of the Related Art Hitherto, as a wiring board, for example, a multilayer wiring board used for a package accommodating a semiconductor element, a multilayer ceramic wiring board capable of relatively high-density wiring has been widely used. 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 the portion, the semiconductor element is housed in the cavity, and the cavity is hermetically sealed by the lid.

In recent years, a high density has been achieved in a wiring board applied to a semiconductor element housing package for mounting semiconductor elements such as IC and LSI, which are becoming highly integrated, and a hybrid integrated circuit device in which various electronic components are mounted. In order to obtain a low dielectric constant, a low resistance metal such as Cu can be used for the wiring circuit layer, and the firing temperature can be reduced. 1
The so-called glass-ceramic wiring board having a temperature of 000 ° C. or less is receiving more attention.

In such a glass ceramic wiring board, Cu and Ag are used as a method for forming a wiring circuit layer.
A metallizing paste whose main component is a wiring conductor made of a metal such as the above is printed on an insulating substrate by a screen printing method or the like. However, when such a method is used, it is difficult to form a wiring width of 100 μm or less, which is a cause of hindering the achievement of higher density and smaller size and weight which are required in the future. Regarding the electric resistance, there are many voids because the wiring circuit layer is formed by the paste, and there is a problem that it is difficult to reduce the resistance.

As a method of solving this problem, there is known a method of forming a wiring circuit layer in a glass ceramic green sheet with an etched metal foil (Japanese Patent Laid-Open No. 63-14493). However, when the metal foil and the glass ceramic are co-fired, the metal foil does not shrink, so that the substrate warps and cracks, which makes it difficult to put into practical use.

Therefore, a constraining sheet made of a layer of an inorganic composition that does not sinter at the firing temperature of the wiring substrate is formed on both sides of the glass ceramic wiring substrate, and then simultaneously fired to shrink the wiring substrate in the plane direction. A method has been proposed in which the metal foil and the glass ceramic can be simultaneously fired by suppressing them (JP-A-7-86743).

[0007]

However, although the ceramics hardly shrinks by firing while restraining the shrinkage of the ceramics, the metal foil slightly shrinks due to the influence of heat. Since the metal foil itself has much higher rigidity than ceramics, there is a problem that this shrinkage causes cracks near the interface between the metal foil and the ceramics during firing. Also, when firing,
Since the wiring circuit layer is formed of a dense metal foil, it is difficult to remove the organic binder contained in the green sheet,
There is a problem that delamination easily occurs between the layers of the sheet.

Accordingly, an object of the present invention is to produce a crack or delamination in an insulating substrate when manufacturing a wiring substrate which is made of glass ceramics as an insulating substrate and a wiring circuit layer made of a metal foil is formed on the surface of the insulating substrate. It is an object of the present invention to provide a method for manufacturing a multilayer wiring board that can stably suppress shrinkage in the planar direction without performing the above.

[0009]

As a result of studying the above-mentioned problems, the inventors of the present invention have found that by increasing the green strength of the glass-ceramic green sheet forming the insulating substrate, the stress generated by the thermal contraction of the metal foil is reduced. As a result that the sheet can sufficiently withstand, the occurrence of cracks can be suppressed, and the constraining sheet can effectively suppress the shrinkage of the glass ceramic insulating substrate.

That is, according to the method for producing a multilayer wiring board of the present invention, a wiring circuit layer made of high-purity metal foil is formed on the surface of a green sheet containing glass powder and inorganic filler powder, and a plurality of the green sheets are laminated. In addition, in the method for manufacturing a multilayer wiring board, which comprises firing the laminate at a temperature equal to or lower than the melting point of the wiring circuit layer while suppressing shrinkage in the planar direction, the tensile strength of the green sheet according to JIS K6251 is 2000. It is characterized by being ~ 5000 KPa.

Further, in such a constitution, the filling rate of the glass powder and the inorganic filler powder in the green sheet is 50% or more, and further, as the organic binder in the green sheet, an acrylic resin, especially i- The tensile strength of the green sheet can be controlled by using BMA (isobutyl methacrylate) and controlling the content of the organic binder in a ratio of 6 to 20 parts by mass with respect to 100 parts by mass of the inorganic component.

High-purity metal foils are made of Cu, Ag, A
1, at least 1 selected from Au, Ni, Pt, and Pd
It is preferable that the thickness of the wiring circuit layer is 30 μm or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a multilayer wiring board according to the present invention will be described below with reference to FIG. 1 which is a process chart showing an example of the method for manufacturing a multilayer wiring board according to the present invention.

In the method for manufacturing a multilayer wiring board according to the present invention, first, as a starting material, the average particle size is 0.5 to 10 μm.
m, especially 1-5 μm glass powder and average particle size 0.5-1
An inorganic filler powder having a particle size of 0 μm, particularly an average particle size of 1 to 5 μm is prepared.

The glass powder used contains at least SiO ₂ as a glass component and contains Al ₂ O ₃ , B ₂ O ₃ and Zn.
A material containing at least one of O, PbO, an alkaline earth metal oxide, and an alkali metal oxide,
For example, SiO ₂ -B ₂ O _{3 based, SiO 2 -B 2 O 3 -Al} 2
Examples include borosilicate glass such as O ₃ —MO type (where M represents Ca, Sr, Mg, Ba or Zn), alkali silicate glass, Ba type glass, Pb type glass, Bi type glass and the like.

[0016] These glasses are also amorphous glasses when they are fired, and when they are fired,
Alkali metal silicate, quartz, cristobalite, cordierite, mullite, enstatite, anorthite, sergian, spinel, garnite, diopside, ilmenite, willemite, dolomite,
A crystal that deposits at least one crystal of petalite or a substituted derivative thereof is used.

Further, as the inorganic filler powder, SiO ₂ such as quartz and cristobalite, Al ₂ O ₃ and Zr are used.
O ₂ , mullite, forsterite, enstatite,
At least one selected from the group of spinel and magnesia is preferably used.

The above glass powder and inorganic filler powder are
In particular, the glass component is mixed with 10 to 90% by weight, especially 40 to 80% by weight, and the ceramic filler component is mixed with 10 to 90% by weight, especially 20 to 60% by weight. Considering the binder removal property and sinterability of the green sheet, the amount of the glass component is preferably 40 to 80% by weight.

After adding an organic binder, a plasticizer and the like to the mixture, it 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 tensile strength of this green sheet is 20 according to JIS K6251.
00-5000KPa, especially 2500-4000KPa
Is important. By controlling the strength of the green sheet within the above range, it is possible to suppress the generation of cracks even when firing the green sheet on which the metal foil is formed while performing the constrained firing, and to remove the organic binder. It is also possible to suppress the occurrence of delamination due to defective binder.

The above-mentioned tensile strength of the green sheet mainly depends on the kind and molecular weight of the organic binder used, the addition amount,
It can be controlled by the filling rate of the inorganic component, the content of the plasticizer, and the like.

First, as the organic binder, it is desirable to use an acrylic resin in order to enhance the strength of the green sheet, remove the binder, and prevent delamination between the substrate layers after firing. As an acrylic resin, i-B
At least one selected from the group consisting of MA (isobutyl methacrylate), N-BMA (normal butyl methacrylate), Et-MA (ethyl methacrylate), and MMA (methyl methacrylate) can be mentioned. Among these, i-BMA is the most preferable. desirable.

When the molecular weight of the organic binder is large, the strength tends to be high, and when the molecular weight is low, the strength tends to be low. Desirably, the molecular weight (MW) is 200,000 to 1,500,000.

Further, as the content of the organic binder increases, the strength of the green sheet can be increased.
From the viewpoint of the strength of this sheet, it is desirable that the amount is 8 parts by mass or more per 100 parts by mass of the inorganic component. However, when the content of the organic binder is too large, it becomes difficult to remove the organic binder and causes delamination. Therefore, the content of the organic binder is preferably 20 parts by mass or less. Optimally, it is 10 to 18 parts by mass.

Further, it is desirable that the filling rate of the inorganic component composed of the glass powder and the inorganic filler powder in the green sheet is 50% or more. If the filling rate is less than 50%, the strength of the sheet will be lower than 2000 KPa. In particular, the filling rate is preferably 51 to 63%. When the sheet is formed by the doctor blade method, the drying temperature of the forming line is preferably 40 ° C to 65 ° C. This is to control the filling rate of the powder in the sheet to the above value.

In addition, a plasticizer such as DBP (dibutyl phthalate) may be added to the green sheet in order to impart elasticity, and the larger the amount of such plasticizer added, the more the sheet is formed. Since the strength tends to decrease, the content of the plasticizer is preferably 3 to 10 parts by mass, particularly 4 to 8 parts by mass with respect to 100 parts by mass of the inorganic component.

The strength of the green sheet is 2000K.
When it is lower than Pa, the green sheet cannot easily withstand the stress generated by the thermal contraction of the wiring circuit layer made of the metal foil when co-fired with the wiring circuit layer of the high-purity metal foil, and thus the green sheet is likely to be cracked. . If it is higher than 5000 KPa, it becomes difficult to remove the organic binder added to the green sheet, and delamination occurs between the substrate layers after firing.

Next, a diameter of 80 to 2 is applied to the green sheet 1 by a laser, a microdrill, punching or the like.
A via hole conductor 2 is formed by forming a through hole of 00 μm and filling the inside with a conductor paste (FIG. 1 (1)).
The conductor paste is formed by mixing a metal component such as Cu and Ag and an organic binder such as an acrylic resin and an organic solvent such as toluene, isopropyl alcohol and acetone. The organic binder is 0.5 to 15.0 parts by mass with respect to 100 parts by mass of the metal component, and the organic solvent is 5 with respect to 100 parts by mass of the solid component and the organic binder.
It is desirable to mix them at a ratio of about 100 parts by mass. A slight amount of glass component or the like may be added to this conductor paste.

Next, the wiring circuit layer 3 is formed on the surface of the green sheet 1. The wiring circuit layer 3 can also be formed by a printing method or the like using a conductor paste containing a metal conductor powder for forming the above-mentioned via-hole conductor 2, but in particular, the width of the wiring circuit layer 3 is 75 μm or less, Especially 50 μm or less, and the pitch of the wiring circuit layer 3 is 150 μm
In order to make fine wiring of m or less, especially 100 μm or less,
It is desirable to use metal foil. As the metal foil, Cu having a purity of 99.5% by weight or more,
It is desirable to be composed of at least one high-purity metal selected from the group consisting of Ag, Al, Au, Ni, Pt, and Pd.
The thickness of the metal foil is preferably 30 μm or less in order to prevent delamination between the substrate layers after firing. In order to improve the adhesion to the green sheet, the surface roughness of at least one of the metal foils is most preferably 0.6 μm or more, particularly 2 μm or more in Rz.

A wiring circuit layer 3 made of such a metal foil
Is known to form a desired circuit by a method such as a well-known photo-etching method after adhering a metal foil to the surface of the green sheet. However, such a method changes the quality of 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 adhered onto the transfer film 5 made of a polymer material, and then a mirror image resist is formed on the surface of the metal conductor. A method in which the resist is applied in the form of a circuit pattern and then the etching treatment and the resist removal are performed is preferable.

Then, the transfer film 5 having the mirror image wiring circuit layer 3 formed thereon is aligned with the surface of the green sheet 1 on which the via-hole conductor 2 is formed and laminated and pressure-bonded,
By peeling off the transfer film 5, the via-hole conductor 2
One unit of the green sheet 1 having the wired circuit layer 3 connected to each other can be formed (FIG. 1 (2)).

Thereafter, a plurality of green sheets 1a to 1d obtained in the same manner are laminated and pressure-bonded to form a laminated body (FIG. 1 (3)). For stacking 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 composed of an organic binder, a plasticizer, a solvent, etc. between the sheets and performing thermocompression bonding, etc. Can be adopted.

Next, in order to suppress shrinkage in the plane direction, the constraining sheet 8 containing a ceramic material that is difficult to sinter at the firing temperature of the laminated body of the green sheets 1a to 1d is used as the glass ceramic green sheets 1a to 1d. The laminated body is manufactured by pressure laminating on both sides or one side of the laminated body of FIG.
(4)).

The restraint sheet 8 is composed mainly of a hardly sinterable ceramic material, and a slurry in which an organic binder, a plasticizer, a solvent and the like are added to an inorganic component to which glass is added in an amount of 0.5 to 15% by mass as required. It is obtained by molding into a sheet. As the non-sinterable ceramic material, specifically, 1000 ° C.
It is composed of a ceramic composition that does not densify at the following temperatures, and specifically has an average particle size of 1 to 20 μm, and particularly 3 to
10 μm Al ₂ O ₃ , SiO ₂ , MgO, ZrO ₂ , B
At least one selected from the group consisting of N and TiO ₂ and /
Or these complex oxides, especially forsterite (M
Examples of the powder include g ₂ SiO ₄ ) and enstatite (MgSiO ₃ ). The organic binder, the plasticizer, and the solvent are the same materials as those that form the glass ceramic green sheet, specifically, acrylic binder, DBP.
And the like, solvents such as IPA, acetone, and toluene can be preferably used.

As the glass component contained in the constraining sheet 8, in order to easily remove the organic component from the glass ceramic green sheet 1, and to improve the adhesiveness between the glass ceramic insulating substrate 10 and the constraining sheet 8. And the softening point is glass ceramic green sheets 1a to 1
It is desirable that the temperature is not higher than the firing temperature of the laminated body of d and higher than the decomposition volatilization temperature of the organic component in the constraining sheet 8. Specifically, the softening point of the glass in the constraining sheet 8 is 450 to 1.
It is preferably about 100 ° C. Furthermore, it is desirable that the glass is a powder having a particle size of 1 to 20 μm.

The glass component contained in the constraining sheet 8 described above may be different from the glass component contained in the glass ceramic green sheet 1, but the diffusion of the glass in the glass ceramic green sheet 1 is prevented. Above all, it is desirable to use the same glass.

Glass-ceramic green sheets 1a-1
The thickness of the constraining sheet 8 laminated on the laminated body of d is a glass ceramic green in consideration of enhancing the constraining force, facilitating the volatilization of the organic component, and considering the removability of the constraining sheet 8 from the glass ceramic insulating substrate 10. Sheets 1a-1
It is preferably 10 to 200% of the thickness of the laminated body of d. The thickness of the restraint sheet 8 refers to the thickness of the restraint sheet 8 laminated on one surface.

Next, the above laminated body was heat-treated 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. After 800-1100
Simultaneous firing in an oxidizing or non-oxidizing atmosphere at ℃. When a conductor such as a Cu conductor that is not oxidized by heat treatment is used as the wiring circuit layer, the firing atmosphere must be a non-oxidizing atmosphere. When a conductor such as an Ag conductor that is not oxidized by heat treatment is used as the wiring circuit layer, the firing is performed. The atmosphere can be an oxidizing atmosphere such as the air.

If the cooling rate after 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 the cooling rate is 400 ° C. It is desirable that it is / hr or less.

In addition, a load may be applied by placing a weight on the upper surface of the laminate to prevent warpage during firing. A suitable load at that time is 50 Pa to 1 MPa.

Thereafter, if desired, the constraining sheet 8 is removed by ultrasonic cleaning, polishing, water jet, chemical blasting, sand blasting, wet blasting, dry blasting or the like, whereby the multilayer wiring board A of the present invention can be manufactured. .

Multilayer wiring board A obtained by the above method
Since the shrinkage during firing is suppressed only in the thickness direction by the restraint sheet 8, the shrinkage in the plane of the laminate is, for example, when the laminate has a rectangular shape, the shrinkage ratio of the length of one side is It is possible to suppress it to 0.5% or less, and since the glass-ceramic green sheet 1 is bonded uniformly and surely over the entire surface by the restraint sheet 8,
It is possible to prevent the restraint sheet 8 from being warped or deformed due to partial peeling or the like (FIG. 1 (5)).

FIG. 2 shows a schematic sectional view of an example of a multilayer wiring board obtained by the above method. According to the multilayer wiring board A of FIG. 2, the insulating substrate 10 has a thickness of 50 to 250.
A plurality of glass ceramic insulating layers 10a to 10d each having a thickness of 10 μm are laminated to form a laminated body.
The thickness is 30 μm between 10 d and on the surface of the insulating substrate 10.
Hereinafter, the wiring circuit layer 3 made of a high-purity metal foil having a thickness of 9 to 18 μm is adhered and formed. Further, a via-hole conductor 2 having a diameter of 80 to 200 μm is formed so as to penetrate the glass ceramic insulating layers 10a to 10d in the thickness direction, thereby connecting the wiring circuit layers 3 to achieve a predetermined circuit. Circuit network is formed. An electronic component B such as a semiconductor element is mounted and mounted on the surface of the wiring circuit layer 3.

Further, in FIG. 2, the wiring circuit layer 3 on the surface is
Is used as a pad for mounting various electronic components B such as an IC chip, as a conductor film for shielding, and as a terminal electrode connected to an external circuit.
Are bonded to the wiring circuit layer 3 via solder or a conductive adhesive. Although not shown, a thick film resistor film such as tantalum silicide or molybdenum silicide or a wiring protection film may be further formed on the surface of the multilayer wiring board A, if necessary.

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

According to the present invention, when the wiring board as described above is manufactured, the wiring circuit layer 3 is formed of a high-purity metal foil, whereby the resistance of the wiring circuit layer 3 can be reduced. At the same time, since shrinkage in the xy direction can be effectively suppressed during firing, a wiring board with high dimensional accuracy can be manufactured. As a result, it is possible to form a highly precise fine pattern as the wiring circuit layer. Further, based on the present invention, the occurrence of cracks near the interface between the wiring circuit layer 3 made of metal foil and the insulating substrate 10,
It is possible to effectively prevent the occurrence of delamination.

[0048]

EXAMPLES First, SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —BaO
Glass powder with an average particle size of 5 μm and an average particle size of 5 μm
m quartz powder was weighed at a ratio of 50% by mass: 50% by mass, and 100 parts by mass of this inorganic component was mixed with isobutyl methacrylate having an average weight molecular weight of 500,000 as an organic binder in the ratio shown in Table 1, and D as a plasticizer
BP (dibutyl phthalate) was mixed at a ratio of 6 parts by mass, and 30 parts by mass of toluene was further added as a solvent and mixed, and the prepared slurry was used to prepare a green sheet having a thickness of 500 μm by a doctor blade method. In order to control the filling rate of the green sheet powder, the drying temperature of the molding line was set to 55 ° C. Regarding the strength evaluation of the manufactured green sheet, a dumbbell-shaped test piece (dumbbell-shaped No. 1 type) was prepared from the green sheet according to JIS K6251 (vulcanized rubber tensile test method), and the test piece was vertically oriented by an autograph. Table 1 shows the tensile strength calculated from the load when the test piece was pulled and cut, and the cross-sectional area of the test piece. In addition, the filling rate of the inorganic components of the green sheet was calculated, and the results are also shown in Table 1.

Next, with respect to Cu powder having an average particle diameter of 5 μm, 8 mass% of SiO ₂ powder as a filler component, and 2 mass parts of acrylic resin as an organic binder with respect to 100 mass parts of these inorganic components, Acetone as solvent 75
The mixture was added and kneaded at a ratio with the mass part to prepare a paste-like paste for via-hole conductors. Then, a via hole was formed in a predetermined portion 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 above Cu, Ag, Ag-Pd, and Ag-Pt metal foils were adhered and etched to form a wiring circuit layer, and a transfer sheet was produced. The wiring width was 50 μm and the wiring circuit layer pitch was 100 μm. However, because of the etching, a very fine wiring circuit layer could be formed as compared with the conventional screen printing method.

Then, an adhesive composed of an 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 green sheet having the via hole is aligned with the position of the via hole. While stacking transfer sheets,
Thermocompression bonding was performed at 15 MPa. After that, the transfer sheet was peeled off to form a wiring circuit layer of one unit including a wiring circuit layer to which the via-hole conductor was connected. Further, five arbitrary one unit green sheets were laminated to form a laminated body.

On the other hand, forsterite powder having an average particle size of ₂ μm and SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ — having an average particle size of 3 μm are used.
A constraining sheet having a thickness of 250 μm and containing 95% by mass and 5% by mass of BaO-based glass powder was prepared. The organic binder, the plasticizer, the solvent and the like during the production of the sheet were the same as the green sheet. This constraining sheet was coated with an adhesive made of an acrylic organic solvent and pressure-laminated on both sides of the green sheet laminate at 60 ° C. and 20 MPa to obtain a laminate comprising the constraining sheet and the glass ceramic green sheet.

Next, this laminated body is placed on an Al ₂ O ₃ setter and heated to 700 ° C. in a nitrogen atmosphere in order to decompose and remove organic components such as an organic binder, and further 950 ° C. in a nitrogen atmosphere. Firing for 1 hour. The cooling rate after firing was 300 ° C / hr. After that, the constraining sheet (inorganic composition which is not sintered) was removed by blasting to produce a multilayer wiring board.

With respect to the obtained multilayer wiring board, the appearance and the cross section of the board were observed to confirm the presence or absence of deformation, delamination and cracks, and for each sample, the occurrence rate in 50 samples was examined.

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

Further, the conduction resistance of the wiring circuit layer was evaluated using this multilayer wiring board. For the evaluation, the wiring resistance at both ends of the wiring circuit layer (width 50 μm) made of copper foil was measured with a tester, the cross section of this wiring circuit layer was scanned with a scanning electron microscope (SEM), and the length of the copper wiring was measured with a microscope. The specific resistance was calculated from the shape of the obtained wiring circuit layer. As a result, in any of the samples, the specific resistance of the wiring circuit layer made of the metal foil was as good as 1.8 to 2.2 μΩ · cm.

[0057]

[Table 1]

As is clear from the results shown in Table 1, the tensile strength of the green sheet was N of less than 2000 KPa.
o. Since Nos. 1, 18 and 19 had low strength, many cracks were generated at the interface between the ceramic insulating substrate and the wiring circuit layer made of metal foil. On the other hand, as the strength increased, the occurrence of cracks was reduced, but the addition amount of the organic binder exceeded 20 parts by mass, and the strength of the green sheet exceeded 5000 KPa. In Nos. 9, 13, and 25, defective binder removal occurred, and delamination frequently occurred between insulating layers.

On the other hand, according to the present invention, the sample No.
In Nos. 2-8, 10-12, 14-17, and 20-24, there is no peeling of the constraining sheet, occurrence of cracks in the glass ceramic insulating substrate, and internal delamination, and the shrinkage rate of the glass ceramic insulating substrate is 0. It had excellent characteristics of 0.5% or less and a wiring circuit layer of 2.2 μΩ · cm or less.

[0060]

As described in detail above, according to the present invention,
By controlling the tensile strength of a green sheet having a wiring circuit layer made of a metal foil, it is possible to suppress peeling of the constraining sheet and the occurrence of cracks in the glass-ceramic insulating substrate, etc. Can be suppressed.

Further, by using a high-purity metal foil as the wiring circuit layer and forming it by a transfer method, it is possible to provide a multi-layer wiring board with low resistance and high dimensional accuracy capable of fine wiring.

[Brief description of drawings]

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

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

[Explanation of symbols]

1 green sheet 2 Via hole conductor 3, 6 wiring circuit layer 5 Transfer film 8 restraint sheet 10 Glass-ceramic insulating substrate A multilayer wiring board B electronic components

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Hamano             Kyocera Co., Ltd. 1-4 Yamashita Town, Kokubun City, Kagoshima Prefecture             Shikisha Research Institute F term (reference) 5E346 AA12 CC16 CC31 CC32 CC34                       CC37 CC38 CC39 DD12 EE22                       EE25 EE30 HH33

Claims (6)

[Claims] 1. A wiring circuit layer made of a metal foil is formed on the surface of a green sheet containing glass powder and inorganic filler powder to laminate a plurality of the green sheets, and the laminated body is below the melting point of the wiring circuit layer. In the method for producing a multilayer wiring board, which is fired at a temperature of 10% while suppressing shrinkage in the plane direction, JIS K625 of the green sheet is used.
The tensile strength based on 1 is 2000 to 5000 KPa. 2. The method for manufacturing a multilayer wiring board according to claim 1, wherein the filling rate of the glass powder and the inorganic filler powder in the green sheet is 50% or more. 3. The organic binder in the green sheet,
An acrylic resin is used, The manufacturing method of the multilayer wiring board of Claim 1 or Claim 2 characterized by the above-mentioned. 4. The green sheet contains the organic binder in an amount of 6 to 20 parts by mass with respect to 100 parts by mass of an inorganic component, according to any one of claims 1 to 3. Manufacturing method of multilayer wiring board. 5. The organic binder contains i-BMA (isobutyl methacrylate).
5. The method for manufacturing a multilayer wiring board according to claim 4. 6. The high-purity metal foil is made of Cu, Ag, A.
1, at least 1 selected from Au, Ni, Pt, and Pd
The method for manufacturing a multilayer wiring board according to any one of claims 1 to 5, which is made of a seed.