JP2010034176A - Multilayer wiring board, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board having an insulating base made of glass-ceramics of high thermal expansion with high chemical resistance which has a dense principal surface, and to provide a method of manufacturing the same. <P>SOLUTION: The insulating base 1 has an inner region 12 containing Si, B, Al, Mg, Ba, Ca, Sr and Zr at a predetermined ratio, and a principal-surface nearby region 11 which contains the same components as the inner region 12, but contains 15 to 23% more Mg in terms of MgO, 3 to 6% less Si in terms of SiO<SB>2</SB>than the inner region 12, and nearly the same amounts of other components as the inner region 12, wherein the inner region 12 has a void rate A2 of 3 to 6% and a maximum void diameter B2 of 6 to 9 μm, the rate A1/A2 of the void rate A1 of the principal-surface nearby region 11 to the void rate A2 of the inner region 12 is not larger than 0.6, and the rate B1/B2 of the maximum void diameter B1 of the principal-surface nearby region 11 to the maximum void diameter B2 of the inner region 12 is not larger than 0.7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a multilayer wiring board having a low resistance wiring such as silver and copper, and a method for manufacturing the same, which are applied to a package for housing a semiconductor element, a high-frequency module substrate, and the like.

  Conventionally, in a multilayer wiring board used in the field of mobile communication, etc., low resistance gold, silver, copper or a mixture thereof is used as a material for a wiring layer, and a wiring layer is used as a material for an insulating substrate composed of a plurality of insulating layers. A multilayer wiring board using glass ceramics that can be fired at a temperature lower than the melting point of the material is widely used.

  When manufacturing this multilayer wiring board, a through hole is formed in the ceramic green sheet that becomes an insulating layer after firing, and the through hole is filled with a conductor material that becomes a through conductor after firing, and the through hole is filled with a conductor material. A conductive material to be a wiring layer is applied to the main surface of the ceramic green sheet. A plurality of ceramic green sheets thus prepared are stacked and fired. Then, the wiring layer provided on the main surface is plated to obtain a multilayer wiring board.

As such a multilayer wiring board, for example, when it is mounted on a printed wiring board (motherboard) having a high thermal expansion coefficient containing an organic resin, a crack may occur in the joint due to a stress due to a difference in thermal expansion with the printed wiring board. A thermal expansion coefficient (high thermal expansion coefficient) having a value close to that of the printed wiring board is known so as not to peel off. Specifically, as a high thermal expansion low temperature fired ceramic (glass ceramic) used as an insulating substrate of a multilayer wiring board, a low temperature fired ceramic comprising 30 to 80% by volume of a glass component and 20 to 70% by volume of a filler component ( Glass ceramics), which includes 25 to 60 mol% of SiO ₂ and 25 to 50 mol% of B ₂ O ₃ in the glass component in a total amount of 65 mol% or more, and includes quartz as a filler component (See Patent Document 1).
JP 2004-231454 A

  Here, in the manufacturing process of the multilayer wiring board using the above glass ceramics as the insulating base, the insulating base is eroded by the plating solution during the plating process, and the plating solution remains in the eroded portion, leaving a black trace. There is a problem.

In addition, in order to remove deposits on the main surface before dipping in the plating solution, so-called jet scrub is performed in which fine Al ₂ O ₃ particles are ejected and sprayed at high speed. There is also a problem that the color changes.

  From the above, an insulating substrate made of glass ceramics is required to have at least a densified main surface and chemical resistance.

  The present invention has been made in view of the above circumstances, and provides a multilayer wiring board provided with an insulating substrate made of glass ceramics having a dense principal surface and excellent chemical resistance and high thermal expansion, and a method for manufacturing the same. Objective.

  As a result of intensive studies to achieve the above object, the present inventor, as a result, in the multilayer wiring board having a composition realizing high thermal expansion, the Mg content and the Si content in the region near the main surface are at a predetermined ratio with respect to the inner region. It has been found that the difference can reduce the void ratio and the maximum void diameter in the vicinity of the main surface and improve the chemical resistance, and the present invention has been achieved.

That is, the present invention is formed on an insulating substrate in which a plurality of insulating layers made of glass ceramics having quartz as a main crystal are laminated, a through conductor formed in the insulating layer, and a main surface and an inside of the insulating substrate. In the multilayer wiring board including the wiring layer, the insulating base includes 65.3 to 66.7% by mass of Si in terms of SiO ₂ , 3.9 to 4.1% by mass of B in terms of B ₂ O ₃ , and Al. 4.7 to 5.5% by mass in terms of Al ₂ O ₃ , 10.9 to 11.1% by mass in terms of MgO, 13.9 to 1.41% by mass in terms of Ca, and Ba in terms of BaO An inner region containing 9.0 to 11.0% by mass, Sr 0.89 to 0.91% by mass in terms of SrO, and Zr 0.60 to 0.71% by mass in terms of ZrO ₂ , and the inner region And the Mg content is higher than that of the inner region. 15-23% Many Si content 3-6% in terms of SiO ₂ reduced by calculation, and the content of the other component has a substantially equal main surface near region and the inner region, the void ratio of the inner region A2 is 3 to 6%, the maximum void diameter B2 of the inner region is 6 to 9 μm, and the ratio A1 / A2 of the void ratio A1 of the main surface vicinity region to the void ratio A2 of the inner region is 0. The ratio B1 / B2 of the maximum void diameter B1 in the region near the main surface to the maximum void diameter B2 in the inner region is not more than 6, and is 0.7 or less.

The present invention, the _{SiO 2 38~50mol%, B 2 O} 3 to 5~10mol%, 4~9mol% of _Al 2 _{O 3,} MgO and 25~38mol%, CaO and 1～3Mol%, a BaO 7 Glass ceramic green containing 60 to 70% by mass of glass powder containing ˜11 mol%, 1 to 4 mol% of SrO and 0.5 to 1.5 mol% of ZrO ₂ , and 30 to 40% by mass of ceramic filler made of SiO ₂ A sheet is formed, a through-hole penetrating the glass ceramic green sheet is formed and filled with a paste for through conductor, and a conductor paste for wiring layer is formed on the main surface of the glass ceramic green sheet, and the glass ceramic is formed. A laminate is prepared by laminating a plurality of green sheets, and 15 to 18% by mass of the glass powder and the ceramic filler. A method for manufacturing a multilayer wiring board and firing by sandwiching the laminate from above and below the green sheet setter and a 82 to 85 mass%.

According to the multilayer wiring board of the present invention, in an insulating substrate in which a plurality of insulating layers made of glass ceramics having quartz as a main crystal are laminated, Si is converted to 65.3 to 66.7% by mass in terms of SiO ₂ and B is added. terms _of B ₂ O ₃ 3.9-4.1 mass%, 4.7 to 5.5 wt% of Al in terms _{of Al} 2 _{O 3,} 10.9 to 11.1 wt% of Mg in terms of MgO, and Ca 1.39 to 1.41% by mass in terms of CaO, 9.0 to 11.0% by mass in terms of BaO, Sr to 0.89 to 0.91% by mass in terms of SrO, and Zr to 0 in terms of ZrO ₂ The inner region containing 60 to 0.71% by mass and the same component as the inner region, the Mg content is 15 to 23% more in terms of MgO than the inner region, and the Si content is 3 to 6 in terms of SiO ₂ % And the content of other components is almost equal to the inner region The inner surface has a void ratio A2 of 3 to 6%, a maximum void diameter B2 of the inner region of 6 to 9 μm, and the main area relative to the void ratio A2 of the inner region The ratio A1 / A2 of the void ratio A1 in the region near the surface is 0.6 or less, and the ratio B1 / B2 of the maximum void diameter B1 in the region near the main surface to the maximum void diameter B2 in the inner region is 0.7 or less. Therefore, it is possible to realize a multilayer wiring board provided with an insulating base with high thermal expansion and excellent chemical resistance. Thereby, even when immersed in the plating solution, erosion by the plating solution due to voids is suppressed, and resistance to trauma due to jet scrub and the like is improved.

According to the method for manufacturing a multilayer wiring board of the present invention, the _{SiO 2 38~50mol%, B 2 O} 3 to 5~10mol%, _Al 2 _{O 3} the 4~9mol%, 25~38mol% of MgO, CaO 1~3mol%, 7~11mol% of BaO, and the glass powder 60-70% by weight containing 0.5 to 1.5 mol% of 1～4Mol% and ZrO ₂ SrO, the ceramic filler 30 made of SiO ₂ A glass ceramic green sheet containing 40% by mass is formed, a through-hole penetrating the glass ceramic green sheet is formed and filled with a paste for through conductor, and a conductor paste for wiring layer is formed on the main surface of the glass ceramic green sheet And a plurality of the glass ceramic green sheets are laminated to produce a laminate, and the glass powders 15 to 1 are formed. Since the laminate is sandwiched and fired from above and below with a green sheet-shaped setter containing 82% by mass and 82 to 85% by mass of the ceramic filler, a multilayer wiring including an insulating substrate with high thermal expansion having excellent chemical resistance A substrate can be obtained.

  Hereinafter, an embodiment of the multilayer wiring board of the present invention will be described.

  FIG. 1 is a schematic cross-sectional view of an embodiment of a multilayer wiring board according to the present invention, and is an explanatory view showing a situation where upper and lower setters after firing are removed.

  The multilayer wiring board shown in FIG. 1 is formed on an insulating substrate 1 in which a plurality of insulating layers are laminated, a through conductor 2 formed in each of the plurality of insulating layers, and a main surface and inside of the insulating substrate 1. A multilayer wiring board including the wiring layer 3. The main surface of the insulating substrate 1 is the surface of the widest area of the insulating substrate 1 and refers to the upper and lower surfaces shown in FIG.

The insulating base 1 is formed by laminating a plurality of insulating layers 1a, 1b, 1c, and 1d. This insulating substrate 1 has a quartz having a high thermal expansion coefficient (13 × 10 ⁻⁶ / ° C. to 15 × 10 ⁻⁶ / ° C.) as a main crystal, and is reliable for secondary mounting with a printed wiring board (motherboard). It is excellent in nature. In addition, since quartz has a low dielectric constant, attenuation of a transmission signal in a high frequency region can be suppressed, and transmission loss due to signal delay can be reduced. In addition to the quartz, the insulating substrate 1 includes crystals such as BaAl ₂ Si ₂ O ₈ (Cerdian) and MgSiO ₃ (enstatite). The presence of these crystals also contributes to the improvement of the thermal expansion coefficient of the insulating substrate 1.

  Here, the insulating substrate 1 can be divided into an inner region 12 (a region other than the main surface vicinity region 11) and a main surface vicinity region 11.

The inner region 12, from 65.3 to 66.7 wt% of Si in terms of SiO _2, 4.7 to 5.5 wt% of Al in terms _{of Al} 2 _{O 3,} the Mg in terms of MgO 10.9 to 11. 1% by mass, B is 3.9 to 4.1% by mass in terms of B ₂ O ₃ , Ba is 9.0 to 11.0% by mass in terms of BaO, and Ca is 1.39 to 1.41% by mass in terms of CaO , Zr is contained in 0.60 to 0.71 mass% in terms of ZrO ₂ and Sr is contained in 0.89 to 0.91 mass% in terms of SrO, which is a composition suitable for high thermal expansion. On the other hand, the main surface vicinity region 11 includes the same components as the inner region 12, 15 to 23% more Si content Mg content in terms of MgO than the inner region 12 has become 3-6% less in terms of SiO ₂ The other components (Al, B, Ba, Ca, Zr, Sr) have almost equal contents in the main surface vicinity region 11 and the inner region 12. Note that “substantially equal” means that the ratio is different due to the difference between the Si content and the Mg content. Further, the percentage of the Si content and Mg content in the main surface vicinity region 11 which are higher or lower than the Si content and Mg content in the inner region 12 is determined from the composition analysis by fluorescent X-ray analysis of each region. It can calculate by calculating | requiring Si content and Mg content of this area | region, and comparing these.

  The void ratio A2 of the inner region 12 is 3 to 6%, the maximum void diameter B2 of the inner region 12 is 6 to 9 μm, and the void ratio A1 of the main surface vicinity region 11 with respect to the void ratio A2 of the inner region 12 is The ratio A1 / A2 is 0.6 or less, and the ratio B1 / B2 of the maximum void diameter B1 of the main surface vicinity region 11 to the maximum void diameter B2 of the inner region 12 is 0.7 or less.

  As described above, the void ratio and the maximum void diameter in the main surface vicinity region 11 are smaller than the void ratio and the maximum void diameter in the inner region 12, so that the insulation having excellent chemical resistance and a dense main surface is achieved. The substrate 1 is obtained. When the void ratio of the main surface vicinity region 11 exceeds 0.6 times the void ratio of the inner region, or the maximum void diameter of the main surface vicinity region 11 exceeds 0.7 times the maximum void diameter of the inner region 12, Sufficient densification of the surface cannot be obtained, and chemical resistance is lowered.

  The main surface vicinity region 11 means a region from the main surface of the insulating substrate 1 to a depth of 20 μm, and the thickness of one insulating layer is usually 60 to 120 μm. The region is thinner than the thickness. That is, in the main surface vicinity region 11, the composition of the green sheet for forming the insulating layers 1a and 1d constituting the outermost layer is different from the composition of the green sheet for forming the insulating layers 1b and 1c constituting the inner layer. It is different from what was made. If the composition of the green sheet for forming the insulating layers 1a and 1d constituting the outermost layer is such that it becomes denser after firing than the green sheet for forming the insulating layers 1b and 1c constituting the inner layer. When these layers are laminated, the shrinkage behavior of each layer is different, so that strain due to stress occurs between the outermost layer and the inner layer, and a large number of minute voids are generated between these layers. Since the structure of the present invention is not obtained by laminating green sheets having different shrinkage behaviors as described above, there is no possibility that voids are generated between the layers.

  The through conductor 2 and the wiring layer 3 are formed of a low resistance conductor whose main component is Cu, Ag or the like. Since the insulating substrate 1 (the plurality of insulating layers 1a, 1b, 1c, 1d) is sintered at a temperature of 1000 ° C. or lower, the main components of the through conductor 2 and the wiring layer 3 have the low melting point. And a low-resistance conductor. In addition, inorganic components such as other metals, oxides, glasses, ceramics, and the like may be included in the main components such as Cu and Ag within a range that does not deteriorate the electrical resistance and thermal conductivity. Moreover, since the through conductor 2 and the wiring layer 3 differ in the manufacturing method by application | coating and filling, subcomponents, such as glass and an inorganic filler, and content may differ, for example.

  In order to obtain such a multilayer wiring board, the following manufacturing method is employed.

First, a ceramic filler is prepared. As the ceramic filler, SiO ₂ which is a natural mineral is used in order to contain quartz, which is a crystal extremely effective for high thermal expansion, in the insulating substrate 1. The average particle size of the ceramic filler is preferably 3.5 to 5.0 μm, and the specific surface area is preferably 1.5 to ^2.5 cm ² / g.

Moreover, a glass powder is prepared. The glass powder has an average particle size of 2.0 to 5.0 μm, 38 to 50 mol% of SiO ₂ , 5 to 10 mol% of B ₂ O _{3, 4} to 9 mol% of Al ₂ O ₃ , and 25 of MgO. ˜38 mol%, CaO 1 to 3 mol%, BaO 7 to 11 mol% and SrO 1 to 4 mol%.

Here, since SiO ₂ is a component that forms a glass network structure, if the content of SiO ₂ is less than 38 mol%, the stability of the glass network structure is deteriorated, and the temperature is low at 850 ° C. to 900 ° C. When firing becomes difficult (sinterability is reduced), the insulating substrate 1 (glass ceramics) is difficult to be densified and chemical resistance is reduced. On the other hand, when the content of SiO ₂ exceeds 50 mol%, Mg ₂ Al ₄ Si ₅ O ₁₈ (cordierite) having a low thermal expansion coefficient (3 × 10 ⁻⁶ / ° C. to 4 × 10 ⁻⁶ / ° C.) is precipitated. When the cordierite is precipitated, the thermal expansion coefficient of the glass ceramic is lowered.

If the content of B ₂ O ₃ is less than 5 mol%, the viscosity of the glass is increased, the glass transition temperature is increased, and the sinterability of the glass ceramic may be lowered. On the other hand, when the content of B ₂ O ₃ exceeds 10 mol%, there is an effect of improving the sinterability by lowering the viscosity of the glass, but the amount of B in the non-crystallized amorphous phase after firing increases. At the same time, the coefficient of thermal expansion decreases due to the inhibition of the crystallization of the glass.

When the content of Al ₂ O ₃ is less than 4 mol%, the glass tends to be devitrified in the step of producing the glass. Devitrified glass may have different glass transition temperature, yielding temperature, crystallization start temperature, etc. compared to non-devitrified glass, so the density of glass ceramics fluctuates even when fired under the same conditions. Since the ratio of the crystals to be deposited differs, various characteristics of the resulting glass ceramics may differ. On the other hand, when the content of Al ₂ O ₃ exceeds 9 mol%, the stability of the network structure in the glass is too good, so that the viscosity of the glass is increased and it becomes difficult to spread and the sinterability is lowered.

  When the content of MgO is less than 25 mol%, it is difficult to suppress devitrification. On the other hand, when the content of MgO exceeds 38 mol%, it is possible to expect densification of the glass ceramics due to an increase in the crystallization start temperature, but cordierite is precipitated and the thermal expansion coefficient of the glass ceramics is reduced. There is a risk that.

  When the content of CaO is less than 1 mol%, the viscosity increases and the sinterability of the glass ceramics decreases. On the other hand, when the content of CaO exceeds 3 mol%, there is an effect of decreasing the glass viscosity at a high temperature range and promoting densification of the glass ceramic and increasing the electrical insulation, but the amount of cordierite deposited is large. Thus, the thermal expansion coefficient of the glass ceramic may be lowered.

  If the BaO content is less than 7 mol%, the BaO amount of the non-crystallized non-crystallized phase after firing is reduced, so that the thermal expansion coefficient of the amorphous phase may be lowered. Further, when the content of BaO exceeds 11 mol%, densification of the glass ceramic can be expected due to an increase in the crystallization start temperature, but there is a possibility that the capacitance decreases and the dielectric constant of the glass increases.

When the content of SrO is less than 1 mol%, the amount of SrAl ₂ Si ₂ O ₈ and Ba _0.9 Sr _0.1 Si ₂ O ₈ deposited decreases, so that high strength of the glass ceramic cannot be expected. Further, if the SrO content exceeds 4 mol%, SrO works as a modified oxide in the glass, so that the effect of reducing the viscosity of the glass and improving the wettability can be expected. As a result, it appears as a bulge on the surface, which may reduce the appearance yield.

  Next, 60 to 70% by mass of glass powder and 30 to 40% by mass of ceramic filler are mixed to produce a glass ceramic green sheet. Specifically, a suitable organic binder and organic solvent are mixed with a mixture of glass powder and ceramic filler (total 100 mass%) to obtain a slurry. From the obtained slurry, a glass ceramic green sheet is produced by a desired forming means such as a doctor blade method, a calender roll method, a rolling method or the like.

Here, when the ratio of the glass powder is less than 60% by mass (the ratio of the ceramic filler exceeds 40% by mass), the amount of glass (liquid phase) is insufficient with respect to the specific surface area of the ceramic filler, so that sintering is performed. There is a risk that the density of the insulating substrate 1 (relative density 95% or more) may not be promoted due to a decrease in the properties. On the other hand, if the ratio of the glass powder exceeds 70% by mass (the ratio of the ceramic filler is less than 30% by mass), the glass amount (liquid phase) increases with respect to the specific surface area of the ceramic filler, so that the sinterability However, a large amount of Mg ₂ Al ₄ Si ₅ O ₁₈ (cordierite) is precipitated from the glass component (glass powder). Thereby, since the amount of deposited quartz is relatively reduced, the thermal expansion coefficient of the insulating substrate 1 (glass ceramic) may be lowered.

  Next, a through-hole is formed in the glass ceramic green sheet by punching or laser processing, and the conductive paste containing Cu powder or Ag powder as a main component is filled in the through-hole. Moreover, a conductor pattern for a wiring layer is formed on a desired glass ceramic green sheet by a screen printing method or a gravure printing method using a conductor paste containing Cu powder or Ag powder as a main component.

  A laminated body is produced by laminating a plurality of thus produced glass ceramic green sheets. Specifically, a laminate is obtained by a thermocompression bonding method or a method of pressurizing and laminating using a lamination aid.

And a laminated body is baked. Here, in firing, a green sheet-like setter containing 15 to 18% by mass of glass powder constituting the glass ceramic green sheet and 82 to 85% by mass of ceramic filler made of SiO ₂ constituting the glass ceramic green sheet. 4 is prepared, and it is important that the laminated body is sandwiched from above and below by the setter 4 and fired. This setter 4 is formed by adding an organic binder and an organic solvent to a mixture of glass powder constituting the glass ceramic green sheet and ceramic filler made of SiO ₂ constituting the glass ceramic green sheet. The amount is appropriately adjusted. The setter 4 is formed to a thickness of about 800 to 1200 μm by, for example, a doctor blade method. Moreover, the average particle diameter of the glass powder which comprises the setter 4 is about 3-5 micrometers, and the average particle diameter of a ceramic filler is about 2-5 micrometers, and it is not managed as severely as a glass ceramic green sheet. FIG. 1 shows a state after the laminate is sandwiched and fired by the setter 4 and the setter 4 is pulled away from the multilayer wiring board after firing.

By using such a setter 4, in the insulating substrate 1 of the multilayer wiring board after firing, the Mg content is 15 to 23% higher than the inner region 12 in terms of MgO, and the Si content is 3 to 6% in terms of SiO _2. A small main surface vicinity region 11 can be formed, the ratio A1 / A2 of the void ratio A1 of the main surface vicinity region 11 to the void ratio A2 of the inner region 12 is 0.6 or less, and the maximum void diameter B2 of the inner region 12 The ratio B1 / B2 of the maximum void diameter B1 in the main surface vicinity region 11 can be set to 0.7 or less. This is considered to be due to the glass component being transferred between the glass ceramic green sheet and the setter 4 constituting the surface layer of the laminate during firing (Si and Mg are moving). It is done.

  Here, when the content of the glass powder exceeds 18% by mass (when the content of the ceramic filler is less than 82% by mass), the denseness of the main surface of the setter 4 after the heat treatment increases and reacts with the insulating substrate 1. There is a possibility that the debye gas discharge route formed by adhesion or burning out of the organic binder may be reduced, and the devitrification property may be lowered. On the other hand, when the content of the glass powder is less than 15% by mass (when the content of the ceramic filler exceeds 85% by mass), the glass component in the setter 4 is relatively reduced, so that the glass ceramic green sheet and the setter are reduced. There is a risk that the glass component (Si and Mg) between 4 and 4 will not be exchanged.

  And the laminated body clamped from the upper and lower sides with the setter 4 is baked at the temperature of 850-900 degreeC. In firing, organic components such as an organic binder blended for molding are first removed. The removal of the organic component is performed by holding at a temperature of 700 to 750 ° C. for 1 to 5 hours in an air atmosphere or a nitrogen atmosphere. Next, as the main baking, baking is performed at a temperature of 850 ° C. to 900 ° C. for 1 to 2 hours. The firing atmosphere is appropriately selected according to the metal species of the wiring layer. A non-oxidizing atmosphere is selected when Cu is used as the wiring layer, and an oxidizing atmosphere is selected when Ag is used.

As the glass powder, a glass powder having the composition shown in Table 1 and a ceramic filler made of SiO ₂ were prepared and weighed and mixed so as to have the ratio shown in Table 1. The average particle size of the glass powder was 3.9 μm, and the average particle size of the filler body was 3.5 μm.

  To this mixture, a binder containing isobutyl methacrylate as a main chain and toluene as a solvent was added as an organic binder, and dibutyl phthalate was added as an organic solvent and mixed well to prepare a slurry. Then, a glass having a thickness of 100 μm was formed by a doctor blade method. A ceramic green sheet was prepared.

  A through-hole is formed in the obtained glass ceramic green sheet by punching, and the through-hole is filled with a paste for penetrating conductors containing Cu as a main component. Further, a wiring layer containing Cu as a main component using a screen printing method. A conductive paste was deposited.

  The plurality of glass ceramic green sheets thus produced were aligned and 14 layers were laminated by thermocompression bonding to obtain a laminate.

On the other hand, a glass powder having the same composition as the glass powder constituting the glass ceramic green sheet and a ceramic filler composed of SiO ₂ having an average particle diameter of 4 μm are mixed so as to have the ratio shown in Table 1, A setter was produced by forming a thickness of 1000 μm by a blade method.

  Then, the laminate is sandwiched from above and below by a setter, debindered at a temperature of 725 ° C. for 3 hours in a nitrogen atmosphere containing water vapor, and then heated at a rate of temperature increase of 300 ° C./Hr. Then, the main baking was performed at a temperature of 860 ° C. for 1 hour in a nitrogen atmosphere to obtain a multilayer wiring board having a length of 45 mm, a width of 45 mm, and a thickness of 5 mm.

  The following measurements were performed on the multilayer wiring board obtained by the above method.

  First, the composition analysis of the main surface vicinity area | region and the inner side area | region was performed, respectively. Specifically, the measurement sample is polished to expose a cross section at a position of 20 μm from the main surface (region near the main surface) and a cross section at a position of 100 μm from the main surface (inner region) to expose the composition of each region. Was measured by fluorescent X-ray analysis. Tables 1 and 2 show the measurement results of the difference (in%) for the composition of the inner region and the components different from the inner region of the main surface vicinity region. Note that the minus display means that the component amount in the main surface vicinity region is small, and the plus display indicates that the component amount in the main surface vicinity region is large.

In addition, the crystal phase in the insulating substrate was identified. This identification was performed by analyzing the X-ray diffraction (XRD) measurement result (peak intensity ratio) by the Rietveld method. Regarding the Rietveld method, the “Crystal Analysis Handbook” Editorial Committee edited by the Crystallographic Society of Japan, “Crystal Analysis Handbook”, Kyoritsu Publishing Co., Ltd., September 1999, p. The method described in 492-499 was used. Specifically, a standard sample of Cr ₂ O ₃ is added to the sample to be evaluated, and RETAN-2000 is applied to an X-ray diffraction pattern in a range of 2θ = 10 ° to 80 ° measured by a diffractometer method. by using the program, from the correlation between the amount of standard samples of Cr ₂ O ₃ was added and the diffraction pattern by standard sample of Cr ₂ O _3, evaluate the crystal structure and the amount contained in a sample to be evaluated did. The results are shown in Table 1 as precipitated crystals. The precipitated crystals were arranged in descending order from the left side.

  Then, the void ratio and the maximum void diameter in the main surface vicinity region and the inner region were measured. First, the measurement sample was cut in the stacking direction, embedded and fixed, and the cut surface was mirror-polished, and then the void state was observed with a secondary electron image of a scanning microscope (SEM). Specifically, a SEM (secondary electron image) is cut out from a cross section at a position of 20 μm from the main surface of the measurement sample (region near the main surface) and a cross section at a position of 100 μm (inner region), and a 500 times SEM photograph is taken. The void ratio and the maximum void diameter were calculated using an image analyzer. Specifically, a void was projected onto the OHP film, and the void portion was painted black. The ratio of the void portion and the dense portion in the porcelain was calculated for the filled OHP with Luzex (metal microscope), and the void ratio and the maximum void diameter were calculated. The results are shown in Table 2.

  Next, the ratio A1 / A2 of the void ratio A1 in the main surface vicinity region to the void ratio A2 in the inner region and the ratio B1 / B2 of the maximum void diameter B1 in the main surface vicinity region to the maximum void diameter B2 in the inner region are obtained. It was. The results are shown in Table 2.

  Furthermore, the thermal expansion coefficient of the obtained insulating substrate was measured. The test piece for measuring the thermal expansion coefficient was a prism with a side of 1.5 mm × 4.5 mm × 15 mm, and the thermal expansion curve from room temperature to 400 ° C. was measured using a thermomechanical analyzer to determine the linear expansion coefficient. . Table 2 shows this value as the thermal expansion coefficient.

  Furthermore, in order to confirm the chemical resistance of the obtained multilayer wiring board, it was immersed in chemicals such as ammonium persulfate, ammonium acid fluoride, and sulfuric acid, and the presence or absence of a red check was confirmed. The results are shown in Table 2.

As shown in Table 1, samples within the scope of the present invention (sample No. 1 to No. 5, No. 7 to No. 10, No. 12 to No. 15, No. 17, No. 18, No. 18, 20, No. 21, No. 23) satisfying a high coefficient of thermal expansion of 10.5 × 10 ⁻⁶ / ° C. or more, and excellent chemical resistance in which erosion of the plating solution due to voids is suppressed. It can be seen that a multilayer wiring board is obtained.

On the other hand, sample No. which is outside the scope of the present invention. In No. 6, since the amount of SiO ₂ in the raw glass powder is small, the amount of precipitation of Serdian (BaAl ₂ Si ₂ O ₈ ) and enstatite (MgSiO ₃ ), which are silicate compounds, is reduced. The coefficient was less than 10.5 × 10 ⁻⁶ / ° C.

In addition, sample No. which is outside the scope of the present invention. No. 11 had a large amount of MgO in the raw glass powder, so cordierite (Mg ₂ Al ₄ Si ₅ O 1 ₈ ) was precipitated and the thermal expansion coefficient was less than 10.5 × 10 ⁻⁶ / ° C. Further, since the Si content in the region near the main surface is not less than 3% less than the inner region, and the Mg content in the region near the main surface is not more than 15% more than the inner region, the void ratio and the maximum void in the region near the main surface The diameter was also outside the scope of the present invention, and the chemical resistance after plating was poor (determination by red check was x).

In addition, sample No. which is outside the scope of the present invention. In No. 16, since the amount of BaO in the raw glass powder is small, the amount of precipitation of Serdian (BaAl ₂ Si ₂ O ₈ ), which is a silicate compound, in the glass ceramic is reduced, so that the thermal expansion coefficient is 10.5. It became less than ^x10 < ^-6 > / ^degreeC .

  In addition, sample No. which is outside the scope of the present invention. 19, since the raw glass powder is less than 60% by mass and the ceramic filler exceeds 40% by mass, the ratio A1 / A2 of the void ratio A1 in the vicinity of the main surface to the void ratio A2 in the inner region in the glass ceramic is The result that the ratio of the maximum void diameter B1 in the main surface vicinity region to the maximum void diameter B2 in the inner region does not satisfy 0.7 or less does not satisfy 0.7 or less, and the chemical resistance after plating is not good. (Judgment by red check is x).

In addition, sample No. which is outside the scope of the present invention. No. 22, the glass powder of the raw material exceeds 70% by mass, and the ceramic filler is less than 30% by mass. Therefore, in the composition of the inner region after firing, the mass of quartz is less than 40% by mass, and the thermal expansion coefficient is 10. It was less than 5 × 10 ⁻⁶ / ° C.

  In addition, sample No. which is outside the scope of the present invention. 24, in a setter that sandwiches a laminate of glass ceramic green sheets from above and below, the glass amount of the setter exceeds 18% by mass and the amount of ceramic filler is less than 82% by mass. Since the surface was not sufficiently densified, the chemical resistance after plating was not good (determination by red check was x).

  In addition, sample No. which is outside the scope of the present invention. No. 25, in a setter that sandwiches a laminated body of glass ceramic green sheets from above and below, the glass amount of the setter is less than 15% by mass, and the amount of ceramic filler exceeds 85% by mass. Similarly to 24, since the main surface of the multilayer wiring board after firing was not sufficiently densified, the chemical resistance after plating was not good (determination by red check was x).

It is explanatory drawing which shows the condition which removes the upper and lower setters after baking while showing the schematic cross section of one Embodiment of the multilayer wiring board of this invention.

Explanation of symbols

1: Insulating substrate 1a, 1b, 1c, 1d: Insulating layer 11: Main surface vicinity region 12: Inner region 2: Through conductor 3: Wiring layer

Claims (2)

Insulating substrate in which a plurality of insulating layers made of glass ceramics having quartz as a main crystal are laminated, a through conductor formed in the insulating layer, and a wiring layer formed in the main surface and inside of the insulating substrate In multilayer wiring boards,
It said insulating substrate is 4.7 to the Si 65.3-66.7 wt% in terms of SiO _2, a B _B 2 _{O 3} in terms of 3.9-4.1 wt%, the Al in terms _{of Al} 2 _{O 3} 5.5% by mass, Mg from 10.9 to 11.1% by mass in terms of MgO, Ca from 1.39 to 1.41% by mass in terms of CaO, and Ba from 9.0 to 11.0% by mass in terms of BaO , an inner region that contains 0.60 to 0.71 wt% from 0.89 to 0.91 wt% of Sr in terms of SrO and Zr in terms of ZrO _2, than the inner region comprises the same components as the interior region 15 to 23% mg content in terms of MgO many Si content 3-6% less in terms of SiO _2, and the content of the other component has a substantially equal main surface near region and the inner region,
The void ratio A2 of the inner region is 3 to 6%, the maximum void diameter B2 of the inner region is 6 to 9 μm, and the ratio of the void ratio A1 of the region near the main surface to the void ratio A2 of the inner region A multilayer wiring board, wherein A1 / A2 is 0.6 or less and a ratio B1 / B2 of a maximum void diameter B1 in the main surface vicinity region to a maximum void diameter B2 in the inner region is 0.7 or less . The _{SiO 2 38~50mol%, B 2 O} 3 to 5~10mol%, _Al 2 _{O 3} the 4~9mol%, MgO of 25~38mol%, 1~3mol% of CaO, 7~11mol% of BaO, SrO was prepared and 1～4Mol% and 60-70 wt% glass powder of ZrO ₂ containing 0.5 to 1.5 mol%, the glass-ceramic green sheet containing a 30 to 40 wt% ceramic filler composed of SiO _2, A through hole penetrating the glass ceramic green sheet is formed and filled with a paste for through conductor, and a conductor paste for wiring layer is formed on the main surface of the glass ceramic green sheet, and a plurality of the glass ceramic green sheets are laminated. To produce a laminated body, and the glass powder 15 to 18% by mass and the ceramic filler 82 to 85 quality. % And a method for manufacturing a multilayer wiring board and firing by sandwiching the laminate from above and below the green sheet setter including.

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