JP4535576B2 - Manufacturing method of multilayer wiring board - Google Patents

Description

【００５４】
【表２】

【００５５】
【表３】

【００５６】
表１〜３の結果から明らかなように、拘束シート中のガラス含有量が０．５体積％以下の試料Ｎｏ．１では、拘束シートがガラスセラミック絶縁基板から剥離してしまい、絶縁基板の収縮率が大きいものであった。また、拘束シート中のガラス含有量が１５体積％を越える試料Ｎｏ．５では、拘束シート自体が収縮して絶縁基板の収縮率が大きくなった。
【００５７】
さらに、ガラスセラミックス絶縁基板と拘束シートとの平均熱膨張係数差が３×１０^-6／℃を越える試料Ｎｏ．７、１２、１３では、いずれもガラスセラミック絶縁基板内にクラックが生じてしまった。
【００５８】
これに対して、本発明に従い、有機バインダーを含む拘束シート中に０．５〜１５体積％のガラス粉末を添加するとともに、拘束シートとガラスセラミック絶縁基板との平均熱膨張係数差を３×１０^−６／℃以下とした試料Ｎｏ．２〜４、１０、１４〜１９では、いずれも拘束シートの剥離やガラスセラミック絶縁基板へのクラックの発生がなく、ガラスセラミック絶縁基板の収縮率が０．５％以下、配線回路層２．２μΩ・ｃｍ以下の優れた特性を有するものであった。
【００５９】
【発明の効果】
以上詳述したとおり、本発明によれば、有機バインダーを含む拘束シート内にグリーンシートに含まれるガラス粉末と同一のガラス成分を所定量添加するとともに、ガラスセラミック絶縁基板と拘束シートとの熱膨張係数を近似させることによって、拘束シートの剥離やガラスセラミック絶縁基板へのクラックの発生等を抑制でき、拘束シートによって効果的にガラスセラミック絶縁基板の収縮を抑制することができる。
【００６０】
また、配線回路層として高純度の金属箔を使用し、転写法によって形成することによって、低抵抗で、微細配線化が可能な高寸法精度の多層配線基板を提供することができる。
【図面の簡単な説明】
【図１】本発明の多層配線基板の製造方法を説明するための工程図である。
【図２】本発明の多層配線基板の製造方法によって得られる多層配線基板の概略断面図である。
【符号の説明】
１ ガラスセラミックグリーンシート
２ ビアホール導体
３、６ 配線回路層
５ 転写フィルム
８ 拘束シート
１０ ガラスセラミック絶縁基板
Ａ 多層配線基板
Ｂ 電子部品[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a multilayer wiring board suitable for a multilayer wiring board, a package for housing semiconductor elements, and the like.
[0002]
[Prior art]
Conventionally, a multilayer ceramic wiring board capable of relatively high density wiring is widely 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 made of metal such as W, Mo, Cu, or Ag formed on the surface thereof. A cavity is formed in the part, a semiconductor element is accommodated in the cavity, and the cavity is hermetically sealed by a lid.
[0003]
In recent years, in a wiring board applied to a package for housing a semiconductor element in which semiconductor elements such as IC and LSI, which have been highly integrated, are mounted, and a hybrid integrated circuit device in which various electronic components are mounted, the density and There is a demand for resistance and reduction in size and weight, and a low dielectric constant is obtained compared to alumina-based ceramic materials, and a low-resistance metal such as Cu can be used as a wiring circuit layer. The so-called glass-ceramic wiring board has attracted more attention.
[0004]
However, in such a glass ceramic wiring board, as a method for forming a wiring circuit layer, a metallized paste mainly composed of a wiring conductor made of a metal such as Cu or Ag is printed on an insulating substrate by a screen printing method or the like. To do. 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 achievement of further higher density and reduction in size and weight that will be required in the future. There was also a problem in that it was difficult to reduce the electrical resistance because there were many voids in order to form the wiring circuit layer with paste.
[0005]
As a method for solving this problem, a method of forming a wiring circuit layer in a glass ceramic green sheet with an etched metal foil is known (Japanese Patent Laid-Open No. 63-14493). However, when the metal foil and the glass ceramic are fired at the same time, the metal foil is not shrunk, so that there is a problem that the substrate warps and cracks occur, making it difficult to put it to practical use.
[0006]
Therefore, a constraining sheet made of an inorganic composition layer that does not sinter at the firing temperature of the wiring substrate is formed on both surfaces of the glass ceramic wiring substrate, and then fired simultaneously to suppress shrinkage in the planar direction of the wiring substrate. Therefore, a method that enables simultaneous firing of metal foil and glass ceramic has been proposed (Japanese Patent Laid-Open No. 7-86743).
[0007]
[Problems to be solved by the invention]
In the method of firing using the restraint sheet described above, the glass ceramic green sheet and the restraint sheet are in close contact with an organic component such as an organic binder contained in the sheet, but the organic component is decomposed by firing. Thereafter, the restraint sheet and the glass ceramic insulating substrate are restrained only by the frictional force, and the shrinkage after firing of the glass ceramic insulating substrate is suppressed.
[0008]
However, in this method, the glass ceramic insulating substrate is restrained only by the frictional force and the shrinkage is suppressed, so that it is easily affected by the surface state of the green sheet and the lamination condition. In some cases, the restraining force of the restraining sheet is reduced. As a result, there is a problem that peeling from the glass ceramic insulating substrate, warping or deformation occurs.
[0009]
Therefore, by adding an amorphous component to the constraining sheet, joining the constraining sheet and the glass ceramic insulating substrate with the amorphous component, and enhancing the adhesion between the two, the constraining force of the constraining sheet And a method for suppressing the shrinkage in the plane direction more stably. However, even in this case, the glass ceramic insulating substrate and the restraining sheet react firmly at the time of firing, so that a thermal stress is generated between the two during cooling after firing, in the glass ceramic insulating substrate or There has been a problem that cracks and the like occur near the constraining sheet adhesion surface of the insulating substrate.
[0010]
An object of the present invention is to provide a method for manufacturing a multilayer wiring board in which glass ceramics is used as an insulating substrate, and a non-sinterable constraining sheet is laminated on the surface of the insulating substrate laminate, and then fired. It is an object of the present invention to provide a method for manufacturing a multilayer wiring board capable of stably controlling the shrinkage in the plane direction without generating cracks or the like.
[0011]
[Means for Solving the Problems]
As a result of studying the above problems, the present inventors have added a predetermined amount of glass component in the constraining sheet and made the constraining sheet approximate the thermal expansion coefficient of the glass ceramic insulating substrate and the constraining sheet to a predetermined range. It has been found that the peeling of the glass ceramic and the generation of cracks in the glass ceramic insulating substrate can be suppressed, and the restraint sheet can effectively suppress the shrinkage of the glass ceramic insulating substrate.
[0012]
That is, the method for producing a multilayer wiring board of the present invention comprises a step of preparing a green sheet containing glass powder and ceramic powder, a step of forming a wiring circuit layer on the surface of the green sheet, and the wiring circuit layer. A step of laminating a plurality of the formed green sheets to form a laminate;
At least one surface of the laminate, with containing as a main component sintering-resistant ceramic material, the same glass component and the glass powder contained in the green sheet contains 0.5 to 15 vol%, and the organic laminating a binding sheet containing a binder, the stacked body restraining sheets are stacked, including the organic binder and then fired at a temperature lower than the melting point of the wiring circuit layer, the surface of the glass ceramic insulating substrate Oyo in beauty and the multilayer wiring board in part that having a wiring circuit layer on the surface of the multilayer wiring board, the average thermal expansion coefficient difference at 40 to 400 ° C. and the glass ceramic insulating substrate is a 3 × 10 -6 ^/ ℃ or less The method includes a step of obtaining a bonded sheet and a step of removing the sheet from the multilayer wiring board .
[0013]
Here, as the flame sinterable ceramic _{material, Al 2 O 3, SiO 3} , MgO, ZrO 2, BN, those mainly containing at least one and / or the composite oxide thereof selected from the group of TiO ₂ It is desirable to use
[0014]
Moreover, it is desirable to use a metal foil as the wiring circuit layer , and it is desirable to use at least one selected from Cu, Ag, Al, Au, Ni, Pt, and Pd as the metal foil.
[0015]
Furthermore, Rukoto to form a wiring circuit layer made of the metal foil so as to fill the inside from the surface of the green sheet is preferable.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the manufacturing method of the multilayer wiring board of the present invention will be described based on the process chart showing an example of the manufacturing method of the multilayer wiring board of the present invention shown in FIG.
First, for example, glass powder having an average particle size of 0.5 to 10 μm, particularly 1 to 5 μm, and ceramic powder having an average particle size of 0.5 to 10 μm, particularly an average particle size of 1 to 5 μm are prepared. The glass component used contains at least SiO ₂ and contains at least one of Al ₂ O ₃ , B ₂ O ₃ , ZnO, PbO, alkaline earth metal oxide, and alkali metal oxide. For example, borosilicate such as SiO ₂ —B ₂ O ₃ , SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ —MO (wherein M represents Ca, Sr, Mg, Ba or Zn) Examples thereof include glass, alkali silicate glass, Ba glass, Pb glass, and Bi glass.
[0017]
These glasses are also amorphous when fired, and by firing, alkali metal silicates, quartz, cristobalite, cordierite, mullite, enstatite, anorthite, serdian, spinel, garnite, diop Those which precipitate at least one kind of crystals of side, ilmenite, willemite, dolomite, petalite and substituted derivatives thereof are used.
[0018]
As the ceramic filler, at least one selected from the group consisting of SiO ₂ such as quartz and cristobalite, Al ₂ O ₃ , ZrO ₂ , mullite, forsterite, enstatite, spinel and magnesia is preferably used.
[0019]
In particular, the glass powder and the ceramic powder are mixed in a proportion of 10 to 90% by volume, particularly 50 to 80% by volume, and 10 to 90% by volume, particularly 20 to 50% by volume, of the ceramic filler component. After adding an organic binder or 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.
[0020]
Next, a through-hole having a diameter of 80 to 200 μm is formed in the green sheet 1 by laser, micro drilling, punching or the like, and a conductor paste is filled therein to form a via-hole conductor 2. The conductive paste is formed by mixing a metal component such as Cu or Ag and an organic binder such as an acrylic resin, toluene, isopropyl alcohol, acetone or the like. The organic binder is desirably mixed in an amount of 0.5 to 15.0 parts by weight with respect to 100 parts by weight of the metal component, and the organic solvent is mixed in an amount of 5 to 100 parts by weight with respect to 100 parts by weight of the solid component and the organic binder. In addition, you may add some glass components etc. in this conductor paste.
[0021]
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 the metal conductor powder for forming the above-described via-hole conductor 2, but the width of the wiring circuit layer 3 is particularly 75 μm or less, In particular, it is desirable to use a metal foil in order to make a fine wiring of 50 μm or less and the wiring circuit layer 3 pitch of 150 μm or less, particularly 100 μm or less. The metal foil is preferably made of at least one high-purity metal selected from the group consisting of Cu, Ag, Al, Au, Ni, Pt, and Pd having a purity of 99% by weight or more.
[0022]
For the wiring circuit layer 3 made of such a metal foil, a method of forming a desired circuit by a technique such as a well-known photo-etching method after bonding the metal foil to the surface of the green sheet is known. Since the green sheet is altered by the etching solution, it is desirable to form it by a transfer method.
[0023]
As a method for forming the wiring circuit layer 3 by the transfer method, first, a high-purity metal conductor, particularly a metal foil, is bonded onto the transfer film 5 made of a polymer material, and then a mirror image resist is applied to the surface of the metal conductor as a circuit pattern. A method of performing etching treatment and resist removal after coating in a shape is suitable.
[0024]
Then, the transfer film 5 on which the mirror circuit wiring circuit layer 3 is formed is aligned with the surface of the green sheet 1 on which the via-hole conductor 2 is formed, and is laminated and pressure-bonded. A unit of the green sheet 1 including the connected wiring circuit layers 3 can be formed.
[0025]
When the transfer film 5 is laminated and pressure-bonded to the surface of the green sheet 1, the wiring circuit layer (metal foil) 3 is removed from the surface of the green sheet 1 by thermocompression bonding at, for example, 50 to 80 ° C. and a pressure of 10 to 20 MPa. It is desirable to forcibly embed in the interior, whereby the difference in thermal expansion between the glass ceramic insulating substrate 10 on which the green sheet 1 is baked and the wiring circuit layer (metal foil) 3, and the restraint sheet 8 and the wiring circuit layer described later. 3 can be prevented from peeling or cracking at the interface due to the difference in thermal expansion from 3. Further, due to the thickness of the highly rigid wiring circuit layer 3 made of metal foil, a gap is generated at the interface between the restraining sheet 8 and the green sheet 1 at the end of the wiring circuit layer 3, and the restraining sheet 8 and the green sheet 1 at that portion. As a result, the end of the wiring circuit layer 3 can be prevented from peeling off during firing.
[0026]
When the wiring circuit layer 6 is formed as the wiring circuit layer 3 such as a ground layer for transmitting a high-frequency signal, the wiring circuit layer 6 occupies 50% or more of the area ratio of the wiring circuit layer to the surface area of the green sheet. When the thermal expansion coefficient of the main component metal of ⁶ is as high as 16 to 17 × 10 ⁻⁶ / ° C., for example, peeling caused by the difference in average thermal expansion coefficient between the wiring circuit layer 6 and the glass ceramic insulating substrate and the restraint sheet In order to prevent cracks, it is desirable to form by the printing method using the above-described conductor paste.
[0027]
Thereafter, a plurality of green sheets 1a to 1d obtained in the same manner are laminated and pressure-bonded to form a laminate. For the lamination of the green sheets 1, a method of applying heat and pressure to the stacked green sheets 1 and thermocompression bonding, a method of applying an adhesive composed of an organic binder, a plasticizer, a solvent, etc. between the sheets, and thermocompression bonding, etc. Can be adopted.
[0028]
Next, in order to suppress the planar direction shrinkage, along with containing as a main component sintering-resistant ceramic material at the firing temperature of the laminate of green sheets 1 a to 1 d, a glass powder contained in the green sheet the same glass component containing 0.5 to 15 vol%, and a binding sheet 8 containing the organic binder in one or both surfaces of the laminate of the green sheets 1a~1d by pressure laminating to prepare a laminate.
[0029]
According to the present invention, the average thermal expansion coefficient difference at 40 to 400 ° C. of glass ceramic insulating substrate 10 obtained by firing the green sheet 1 and the restraining seat 8 (hereinafter, simply referred to as average thermal expansion coefficient difference.) Is 3 × 10 ⁻⁶ / ° C. or less, particularly 2 × 10 ⁻⁶ / ° C. or less, which causes cracks or peeling that occurs near the bonding surface of the restraining sheet 8 of the glass ceramic insulating substrate 10 during cooling after firing. Or, cracks generated in the glass ceramic insulating substrate 10 can be prevented.
[0030]
In the present invention, the glass ceramic insulating substrate 10 has a thermal expansion coefficient of 8 × in order to reduce the difference in average thermal expansion coefficient from an external circuit board such as a printed circuit board and improve mounting reliability. It is desirably 10 ⁻⁶ / ° C. or higher, particularly 9 to 17 × 10 ⁻⁶ / ° C. or higher. Further, in terms of reducing the firing shrinkage on the surface (main plane) of the glass ceramic insulating substrate 10, it is desirable that the thermal expansion coefficient of the constraining sheet 8 is less than or equal to the thermal expansion coefficient of the glass ceramic insulating substrate 10, and the glass ceramic insulating substrate. From the standpoint that the tensile stress associated with the difference in thermal expansion does not remain in 10, it is desirable that the thermal expansion coefficient of the constraining sheet 8 be equal to or greater than the thermal expansion coefficient of the glass ceramic insulating substrate 10. In particular, it is desirable that the thermal expansion coefficient of the restraint sheet 8 is equal to or less than the thermal expansion coefficient of the glass ceramic insulating substrate 10.
[0031]
This restraint sheet 8 containing an organic binder is a sheet-like slurry in which an organic binder, a plasticizer, a solvent and the like are added to an inorganic component mainly composed of a hardly sinterable ceramic material and containing 0.5 to 15% by weight of glass. It can be obtained by molding. The hardly sinterable ceramic material is specifically composed of a ceramic composition that does not become densified at a temperature of 1000 ° C. or less, and specifically, Al ₂ O having an average particle diameter of 1 to 20 μm, particularly 3 to 10 μm. ₃ , at least one selected from the group consisting of SiO ₂ , MgO, ZrO ₂ , BN, TiO ₂ and / or composite oxides thereof, in particular powders such as forsterite (Mg ₂ SiO ₄ ), enstatite (MgSiO ₃ ), etc. Is mentioned. Further, an organic binder, a plasticizer and the same materials as those for forming the green sheet as a solvent, specifically acrylic binder, plasticizer DBP, etc., IPA, acetone, solvent, etc. can be suitably used, such as toluene .
[0032]
According to the present invention, it is important to contain the same glass Ingredients glass powder contained in the green sheet into this restraining seat 8 0.5 to 15 vol%. It the amount of glass is less than 0.5 vol%, binding force firing shrinkage of the glass ceramic green sheet 1 by restraining seat 8 is small, the glass component side restraining seat 8 from green sheet 1 at the firing step As a result of diffusion and movement due to capillary action, many voids are generated on the surface of the sintered glass ceramic wiring board 10. Conversely, if the amount of glass is more than 15 vol%, binding sheet 8 itself results shrinks by sintering starts sintering, it becomes difficult to suppress the shrinkage of the green sheet 1, sintered This is because it becomes difficult to remove the restraint sheet 8 from the glass ceramic wiring board 10 later. The preferred glass amount of the restraint sheet 8 is 1 to 12% by volume, and the most preferred range is 3 to 10% by volume.
[0033]
As the glass component contained in the binding sheet 8 comprising an organic binder, for easy removal of the organic components from the green sheet 1, and for increasing the adhesion between the glass-ceramic insulating substrate 10 and the restraining seat 8 in, in the following the firing temperature of the laminate of the softening point is green sheet 1 a to 1 d, and higher is more desirable than the decomposition volatilization temperature of the organic components in restraining seat 8 containing the organic binder. Specifically, the softening point of the glass component in the constraining sheet 8 containing the organic binder is preferably about 450 to 1100 ° C. Furthermore, the glass component is desirably a powder of 1 to 20 μm.
[0034]
The glass component contained in the binding sheet 8 containing the above-mentioned organic binder, the same glass component in preventing the diffusion of glass in the green sheet 1.
[0035]
According to the present invention, the thermal expansion coefficient of the constraining sheet 8 can be adjusted by changing the kind of the hardly sinterable ceramic material and glass and the particle size of the powder.
[0036]
The thickness of the restraining seat 8 containing an organic binder which is laminated on the laminate of green sheets 1a~1d, the removal of the restraining seat 8 from the glass ceramic insulating substrate 10 One only facilitate volatilization of organic components to increase the restraining force considering sex may be 10 to 200% of the thickness of the laminate of green sheets 1 a to 1 d. In addition, the thickness of the restraint sheet 8 containing the said organic binder points out the thickness of the restraint sheet 8 containing the organic binder laminated | stacked on one surface.
[0037]
Next, the laminated body is 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 via-hole conductor paste, and then 800 Co-firing in an oxidizing or non-oxidizing atmosphere at ˜1100 ° C. In addition, when using a conductor that is not oxidized by heat treatment such as a Cu conductor as the wiring circuit layer, the firing atmosphere needs to be performed in a non-oxidizing atmosphere. When using a conductor that is not oxidized by heat treatment such as an Ag conductor as the wiring circuit layer, firing The atmosphere can be an oxidizing atmosphere such as air.
[0038]
If the cooling rate after firing in this firing is too fast, cracks are generated due to temperature differences and thermal expansion differences between the insulating substrate 10, the wiring circuit layer 3, and the constraining sheet 8, so the cooling rate is 400 ° C./hr or less. It is desirable that
[0039]
Further, a load may be applied by placing a weight on the upper surface of the laminate in order to prevent warping during firing. The load is suitably 50 Pa to 1 MPa.
[0040]
Thereafter, the multilayer wiring board A of the present invention can be produced by removing the constraining sheet 8 by ultrasonic cleaning, polishing, water jet, chemical blasting, sand blasting, wet blasting, or the like, if desired.
[0041]
In the multilayer wiring board A obtained by the above method, the shrinkage at the time of firing is suppressed only in the thickness direction by the restraint sheet 8, so the shrinkage in the plane of the laminate is, for example, when the laminate is rectangular. , it is possible to one side of the length of shrinkage reduced to 0.5% or less, since deer even green sheet 1 is uniformly and securely bonded over the entire surface by restraining seat 8, one restraining seat 8 It is possible to prevent warping or deformation from occurring due to partial peeling or the like.
[0042]
A schematic cross-sectional view of an example of a multilayer wiring board obtained by the above method is shown in FIG.
According to the multilayer wiring board A of FIG. 2, the insulating substrate 10 is composed of a laminate formed by laminating a plurality of glass ceramic insulating layers 10a to 10d having a thickness of 50 to 250 μm, and the insulating layers 10a to 10d and the insulating layers are insulated. A wiring circuit layer 3 made of high-purity metal foil having a thickness of about 9 to 18 μm is deposited on the surface of the substrate 10. Further, a via-hole conductor 2 having a diameter of 80 to 200 μm formed so as to penetrate the thickness direction of each glass ceramic insulating layer 10a to 10d is formed, 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 on the surface of the wiring circuit layer 3.
[0043]
In FIG. 2, the wiring circuit layer 3 on the surface is used as a pad for mounting various electronic components B such as an IC chip, as a conductor film for shielding, and further as a terminal electrode connected to an external circuit. The electronic component B is 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 protective film, or the like may be further formed on the surface of the multilayer wiring board A if necessary.
[0044]
Further, in FIG. 2, a wiring circuit layer forming a ground layer formed by printing the above-described conductor paste is formed inside the insulating layers 10a to 10d.
[0045]
【Example】
First, a crystallized glass and a ceramic filler shown in Table 1 are weighed, and an acrylic resin as a binder, DBP (dibutyl phthalate) as a plasticizer, toluene and isopropyl alcohol as solvents and a mixture and a prepared slurry are used. A green sheet having a thickness of 500 μm was prepared by a doctor blade method. Table 1 shows the thermal expansion coefficient at 40 to 400 ° C. of glass ceramics obtained by firing the above-mentioned green sheet in the firing conditions described below (in nitrogen, at 950 ° C. for 1 hour).
[0046]
Next, for Cu powder having an average particle size of 5 μm, 8% by weight of SiO ₂ powder as a filler component, 2 parts by weight of acrylic resin as an organic binder for these inorganic components, and 75% by weight of acetone as a solvent. The paste was added and kneaded at a ratio to the part to prepare a paste for via-hole conductor. And the via hole was formed in the predetermined location of the green sheet, and the said via hole paste was filled in the via hole.
[0047]
On the other hand, the metal film shown in Table 1 having a purity of 99.5% or more was bonded to the polymer film, and etching was performed to form a wiring circuit layer, thereby producing a transfer sheet. Although the wiring width was 50 μm and the wiring layer pitch was 100 μm, a very fine wiring circuit layer could be formed as compared with the conventional screen printing method because of the formation by etching.
[0048]
Then, after applying the adhesive composed of the organic component used for forming the green sheet to the wiring circuit layer forming surface of the transfer sheet by screen printing, the transfer sheet is aligned with the position of the via hole on the green sheet in which the via hole is formed. Was laminated by thermocompression bonding at 60 ° C. and 15 MPa to embed the wiring circuit layer from the green sheet surface to the inside. Thereafter, the transfer sheet was peeled off to form a unit wiring layer including a wiring circuit layer to which via-hole conductors were connected. Further, five sheets of these arbitrary unit green sheets were laminated to form a laminate.
[0049]
On the other hand, a constraining sheet containing an organic binder having a thickness of 250 μm made of a composition of ceramic powder having an average particle diameter of 2 μm and glass powder having an average particle diameter of 5 μm shown in Table 2 was prepared. The organic binder, plasticizer, solvent, and the like at the time of preparing the sheet were the same as the green sheet, and Table 2 shows the average thermal expansion coefficient at 40 to 400 ° C. after firing, which will be described later. The constraining sheet containing this organic binder was pressure laminated at 60 ° C. and 20 MPa on both sides of the green sheet laminate to obtain a laminate.
[0050]
Next, this laminate is 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, and further in a nitrogen atmosphere at 950 ° C. Firing was performed for 1 hour. The cooling rate after firing was set to 300 ° C./hr. Thereafter, the constraining sheet (inorganic composition that was not sintered) was removed by blasting to produce a multilayer wiring board.
[0051]
The appearance of the obtained multilayer wiring board was observed to confirm the presence or absence of deformation and cracks. Moreover, the conduction resistance of the wiring circuit layer was evaluated using this multilayer wiring board. For evaluation, wiring resistance was measured with a tester at both ends of a wiring circuit layer (width 50 μm) made of copper foil, a cross section of the 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.
[0052]
Further, the shrinkage rate due to firing of the glass ceramic insulating substrate was measured by measuring the length of one side before and after firing of the insulating substrate (l ₁ , l ₂ ), and the shrinkage rate ((l ₁ −l ₂ ) / l ₁ × 100. %) Was calculated. The results are shown in Table 3.
[0053]
[Table 1]

[0054]
[Table 2]

[0055]
[Table 3]

[0056]
As is clear from the results in Tables 1 to 3, the sample No. In No. 1, the constraining sheet was peeled off from the glass ceramic insulating substrate, and the shrinkage rate of the insulating substrate was large. Further, the sample No. in which the glass content in the constraining sheet exceeds 15% by volume. In 5, the restraint sheet itself contracted and the contraction rate of the insulating substrate increased.
[0057]
Further, the sample No. in which the difference in average thermal expansion coefficient between the glass ceramic insulating substrate and the constraining sheet exceeds 3 × 10 ⁻⁶ / ° C. In Examples 7, 12, and 13, cracks occurred in the glass ceramic insulating substrate.
[0058]
On the other hand, according to the present invention, 0.5 to 15% by volume of glass powder is added to the constraining sheet containing the organic binder, and the difference in average thermal expansion coefficient between the constraining sheet and the glass ceramic insulating substrate is 3 × 10. ^-6 / ° C. to not more than sample No. In 2-4, 10 and 14-19, none of the restraint sheet was peeled off or cracks were generated in the glass ceramic insulating substrate, the shrinkage rate of the glass ceramic insulating substrate was 0.5% or less, and the wiring circuit layer was 2.2 μΩ. -It had the outstanding characteristic below cm.
[0059]
【The invention's effect】
As described above in detail, according to the present invention, a predetermined amount of the same glass component as the glass powder contained in the green sheet is added to the constraining sheet containing the organic binder, and the thermal expansion of the glass ceramic insulating substrate and the constraining sheet is performed. By approximating the coefficient, it is possible to suppress peeling of the constraining sheet, generation of cracks in the glass ceramic insulating substrate, and the like, and it is possible to effectively suppress shrinkage of the glass ceramic insulating substrate by the constraining sheet.
[0060]
Further, by using a high-purity metal foil as the wiring circuit layer and forming the wiring circuit layer by a transfer method, it is possible to provide a multilayer wiring board having a high dimensional accuracy with low resistance and enabling fine wiring.
[Brief description of the drawings]
FIG. 1 is a process diagram for explaining a method for producing 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]
DESCRIPTION OF SYMBOLS 1 Glass ceramic green sheet 2 Via-hole conductors 3 and 6 Wiring circuit layer 5 Transfer film 8 Restraint sheet 10 Glass ceramic insulating board A Multilayer wiring board B Electronic component

Claims (6)

Preparing a green sheet containing glass powder and ceramic powder ;
Forming a wiring circuit layer on the surface of the green sheet ;
Forming a laminate by laminating a plurality of the green sheets on which the wiring circuit layer is formed ;
At least one surface of the laminate, with containing as a main component sintering-resistant ceramic material, the same glass component and the glass powder contained in the green sheet contains 0.5 to 15 vol%, and the organic Laminating a constraining sheet containing a binder ;
The laminate is bound sheet comprising the organic binder are laminated and fired at a temperature below the melting point of the wiring circuit layer, multi-layer wiring each time the unit Oyo surface of the glass-ceramic insulating substrate that having a wiring circuit layer Obtaining a substrate and a surface of the multilayer wiring substrate to which a constraining sheet having an average coefficient of thermal expansion of 40 to 400 ° C. between the glass ceramic insulating substrate and 3 × 10 ⁻⁶ / ° C. or less is bonded;
And a step of removing the constraining sheet from the multilayer wiring board. As the flame sinterable ceramic _{material, Al 2 O 3, SiO 3} , MgO, ZrO 2, BN, be those mainly at least one and / or the composite oxide thereof selected from the group consisting of TiO ₂ The method for producing a multilayer wiring board according to claim 1. Wherein as the glass component contained in the binding sheet containing an organic binder, according to claim 1 or 2 a method for manufacturing a multilayer wiring board wherein the use of what softening point is below the shrink forming temperature. Examples wiring circuit layers, a method for manufacturing a multilayer wiring board according to any one of claims 1 to 3, characterized in that a metal foil. 5. The method of manufacturing a multilayer wiring board according to claim 4, wherein at least one selected from Cu, Ag, Al, Au, Ni, Pt, and Pd is used as the metal foil. Method for manufacturing a multilayer wiring board according to claim 4, wherein that you form a wiring circuit layer made of the metal foil so as to fill the inside from the surface of the green sheet.

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