JP2010056271A - Multilayer wiring board and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer wiring board having wiring using a low-resistance conductor as a main component and high in coefficient of thermal expansion and insulation reliability and a method of manufacturing the board. <P>SOLUTION: The invention is characterized in that in the multilayer wiring board of the type that a through conductor 2 and a wiring layer 3 having at least one kind of low resistance conductors selected from a group consisting of Cu, Ag and Au as the main component are formed in an insulating substrate 1 formed by laminating a plurality of glass ceramic insulating layers 11, 12, 13, 14 containing quartz as a main crystal and forsterite as a sub crystal, the void fraction of the insulating substrate 1 is not more than 5%, the content of quartz is 30 to 40 mass%, the content of forsterite is 16 to 25 mass% and the content of cordierite is less than 1.0 mass% in the insulating substrate 1 obtained by the Rietveld analysis from the peak intensity of X-ray diffraction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is applied to a package for housing a semiconductor element, a high-frequency module substrate, and the like, and relates to a multilayer wiring board having wiring mainly composed of a low-resistance conductor and a manufacturing method thereof.

  In recent years, with the advent of the advanced information era, information transmission has become faster and higher in frequency, and mounted semiconductor elements are more highly integrated, and electronic devices that process high-frequency signals above GHz level, such as optical communication and high-speed interfaces. Electronic devices such as mobile phones and PDAs (Personal Digital Assistants) are rapidly spreading.

  The wiring board used in such electronic devices is printed on the printed circuit board due to the stress caused by the difference in thermal expansion between the printed circuit board and the printed circuit board. The thermal expansion coefficient of the insulating substrate constituting the wiring board is the thermal expansion coefficient of the printed wiring board in order to prevent the solder joint with the wiring board from peeling off or cracking in the solder joint. And a value close to (high thermal expansion coefficient).

In response to this requirement, the insulating substrate contains 5 to 30% by weight of Li ₂ O, 20 to 80% by volume of lithium silicate glass having a yield point of 400 to 800 ° C., and a filler containing at least forsterite and quartz. Wiring comprising a sintered body having a linear thermal expansion coefficient of 8 to 18 ppm / ° C. at 40 ° C. to 400 ° C. obtained by firing a molded body containing 20 to 80% by volume of the total amount of components. A substrate has been proposed (see Patent Document 1).
Japanese Patent Laid-Open No. 9-74153

  However, in the wiring board described in Patent Document 1, an insulating base made of a sintered body having a high thermal expansion coefficient can be obtained by increasing the filler component containing forsterite and quartz. Since the component is reduced and the sinterability is lowered, a sintered body having a low void ratio (void ratio of 5% or less) cannot be obtained.

  On the other hand, in order to cope with higher speed of information transmission and higher integration of semiconductor elements, it is also required that the insulating layer is a thin layer with a narrow pitch. Therefore, it is necessary to ensure high insulation reliability by using an insulating substrate with a low void ratio.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multilayer wiring board including a wiring mainly composed of a low-resistance conductor and having a high thermal expansion coefficient and insulation reliability, and a method for manufacturing the same. .

  The present invention mainly includes at least one low-resistance conductor selected from the group consisting of Cu, Ag, and Au inside an insulating substrate in which a plurality of glass ceramic insulating layers containing quartz as a main crystal and forsterite as a subcrystal are laminated. In a multilayer wiring board having through conductors and wiring layers as components, the void ratio of the insulating base is 5% or less, and the quartz content in the insulating base determined by Rietveld analysis from the peak intensity of X-ray diffraction The amount is 30 to 40% by mass, the forsterite content is 16 to 25% by mass, and the cordierite content is less than 1.0% by mass.

The present invention also includes a step of making a ceramic filler by attaching a plurality of TiO ₂ particles at a ratio of 3 to 10 parts by mass with respect to 100 parts by mass of the filler body so as to cover the surface of the filler body made of quartz, and 38～50Mol% of Si in terms of SiO _2, and 5 to 10 mol% of B in terms _of B 2 _{O 3,} and 4～9Mol% of Al in terms _{of Al} 2 _{O 3,} and 25～38Mol% of Mg in terms of MgO A step of preparing a glass powder containing 1 to 3 mol% of Ca in terms of CaO and 7 to 11 mol% of Ba in terms of BaO, and 30 to 40% by mass of the filler body and 60 to 70 of the glass powder. A step of producing a glass ceramic green sheet containing the ceramic filler and the glass powder so as to have a mass% ratio, and the glass ceramic green Forming a through-hole penetrating the sheet and filling the through-conductor paste and applying a wiring layer conductor paste to one main surface of the glass ceramic green sheet; and filling the through-conductor paste and the A step of producing a glass ceramic green sheet laminate by laminating a plurality of the glass ceramic green sheets coated with the conductor paste for wiring layers; and a step of firing the glass ceramic green sheet laminate. A method for manufacturing a multilayer wiring board.

According to the multilayer wiring board of the present invention, quartz having a high thermal expansion coefficient (13 to 15 × 10 ⁻⁶ / ° C.) is 30 to 40% by mass, and a high thermal expansion coefficient (about 10 × 10 ⁻⁶ / ° C.). By containing the forsterite having 16 to 25% by mass, an insulating substrate having a high thermal expansion coefficient can be realized. Thereby, the secondary mounting reliability with the external circuit board (printed wiring board) of a multilayer wiring board is securable.

  Further, according to the multilayer wiring board of the present invention, since the insulating base made of the glass ceramic insulating layer has a void ratio of 5% or less, high insulation reliability can be obtained.

According to the method for manufacturing a multilayer wiring board of the present invention, a glass powder having a composition for precipitating a high thermal expansion forsterite crystal, and 100 parts by mass of the filler body so as to cover the surface of the filler body made of quartz. A ceramic filler having a plurality of TiO ₂ particles attached at a rate of 3 to 10 parts by mass is mixed so that the filler body is 30 to 40% by mass and the glass powder is 60 to 70% by mass. Since a ceramic green sheet is produced, laminated and fired, a multilayer wiring board having a high thermal expansion coefficient and an insulating base with a void ratio of 5% or less can be obtained.

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

  FIG. 1 is a schematic sectional view of an embodiment of a multilayer wiring board according to the present invention. The multilayer wiring board shown in FIG. 1 includes a glass ceramic insulating layer 11 in an insulating substrate 1 in which a plurality of glass ceramic insulating layers 11, 12, 13, and 14 containing quartz as a main crystal and forsterite as a sub crystal are laminated. , 12, 13, and 14, and a wiring layer 3.

The 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 specifically contains 30 to 40% by mass of quartz. is doing. This quartz is mixed as a ceramic filler in the raw material stage (glass ceramic green sheet) and remains in the glass ceramic insulating layers 11, 12, 13, 14 after firing in an almost intact ratio. Since quartz has a high coefficient of thermal expansion, the presence of quartz is extremely important for increasing the coefficient of thermal expansion of the insulating substrate 1. 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.

  Here, it is important that the quartz content in the insulating substrate 1 determined by Rietveld analysis from the peak intensity of X-ray diffraction is 30 to 40% by mass. If the quartz content is less than 30% by mass, a sufficiently high coefficient of thermal expansion cannot be obtained. If it exceeds 40% by mass, the raw material ceramic filler is large, so the sinterability is reduced and the void ratio is high. Because it becomes.

In addition, it is important that the content of forsterite (Mg ₂ SiO ₄ ) in the insulating substrate 1 obtained by Rietveld analysis from the peak intensity of X-ray diffraction is 16 to 25% by mass. Although forsterite is a crystal having a high thermal expansion coefficient (about 10 × 10 ⁻⁶ / ° C.), although not as much as quartz, the presence of forsterite also contributes to increasing the thermal expansion coefficient of the insulating substrate 1. . This is because if the forsterite content is less than 16% by mass, the amount of enstatite having a lower thermal expansion coefficient than that of forsterite increases, and a sufficiently high thermal expansion coefficient cannot be obtained. When the forsterite content exceeds 25% by mass, a high thermal expansion coefficient can be obtained, but voids increase as the content increases.

In addition, it is important that the cordierite (Mg ₂ Al ₄ Si ₅ O ₁₈ ) content in the insulating substrate 1 obtained by Rietveld analysis from the peak intensity of X-ray diffraction is less than 1.0% by mass. Since cordierite is a crystal having a low coefficient of thermal expansion (3-4 × 10 ⁻⁶ / ° C.), when it is precipitated until the cordierite content is 1.0 mass% or more, the content of quartz and forsterite Even in the above range, the thermal expansion coefficient of the insulating substrate 1 is lowered. Therefore, it is important that the cordierite content is less than 1.0% by mass.
The presence of forsterite also contributes to increasing the thermal expansion coefficient of the insulating substrate 1. This is because if the forsterite content is less than 16% by mass, the amount of enstatite having a lower thermal expansion coefficient than that of forsterite increases, and a sufficiently high thermal expansion coefficient cannot be obtained. When the forsterite content exceeds 25% by mass, a high thermal expansion coefficient can be obtained, but voids increase as the content increases.

  Furthermore, it is important that the insulating substrate 1 has a void ratio of 5% or less. Because forsterite is a crystal deposited from glass rather than being mixed as a ceramic filler in the raw material stage, it has a high thermal expansion while having a void ratio of 5% or less, unlike those with low raw glass and low sinterability. It was possible to realize. Thereby, when immersed in a plating solution, erosion by the plating solution due to voids is suppressed.

In addition to the quartz and forsterite, the insulating substrate 1 contains, for example, enstatite (6-8 × 10 ⁻⁶ / ° C.) having a relatively high thermal expansion coefficient in a proportion of 5 to 15% by mass. The total amount of occupies 70-80 mass% of the insulating substrate 1. In addition, glass (non-crystalline phase) exists in the crystal grain boundary, and in this glass, in addition to Si, B, Al, Mg, Ca and Ba contained in glass powder as a raw material powder described later As shown in FIG. 2, Ti resulting from a plurality of TiO ₂ particles 42 attached so as to cover the filler main body 41 is included.

  The insulating substrate 1 is provided with a through conductor 2 and a wiring layer 3 mainly composed of at least one low resistance conductor selected from the group consisting of Cu, Ag and Au, thereby forming a multilayer wiring board. . Since the insulating substrate 1 is made of the glass ceramic described above, it can be fired at a low temperature of 800 ° C. to 1000 ° C. in the manufacturing process, and therefore a group of Cu, Ag and Au having a low resistance and a low melting point. The main component is at least one low-resistance conductor selected from The through conductor 2 and the wiring layer 3 contain other metal, glass, oxide, carbide, nitride, and other inorganic components as long as they do not deteriorate the electrical resistance and thermal conductivity as necessary. Also good.

As described above, the multilayer wiring board of the present invention can have a thermal expansion coefficient of the insulating base 1 as high as 11.5 × 10 ⁻⁶ / ° C. or higher, and can be compared with a printed wiring board (mother board). The next mounting reliability will be excellent. Moreover, the multilayer wiring board of the present invention can have a void ratio as low as 5% or less, and has excellent insulation reliability.

  An embodiment of a method for manufacturing a multilayer wiring board according to the present invention will be described.

First, a ceramic filler is produced. As shown in FIG. 2, the ceramic filler has a configuration in which a plurality of TiO ₂ particles 42 are attached so as to cover the surface of the filler main body 41 made of quartz. The average particle diameter of the TiO ₂ particles is 0.1 μm or less while the average particle diameter of the filler body 41 is 2.0 to 5.0 μm.

  Quartz, which is a material for forming the filler body 41, is a crystal that is extremely important for achieving high thermal expansion, and is contained in the insulating substrate 1 after being fired at an almost unchanged rate contained in the glass ceramic green sheet.

Further, when the TiO ₂ particles 42 are attached so as to cover the surface of the filler main body 41 made of quartz at a desired ratio, the wettability between the filler main body 41 and the glass powder is improved, and the core is formed at an early stage of firing. It serves as a forming material and promotes crystal growth of glass. As a result, forsterite can be precipitated efficiently. Here, the desired ratio is a ratio of 3 to 10 parts by mass with respect to 100 parts by mass of the filler body 41. If the amount of the plurality of adhered TiO ₂ particles 42 is less than 3 parts by mass with respect to 100 parts by mass of the filler body 41, it becomes difficult to deposit forsterite in an amount of 16% by mass or more in the insulating base 1 after firing. High thermal expansion cannot be achieved. On the other hand, if the amount of the plurality of adhered TiO ₂ particles 42 exceeds 10 parts by mass with respect to 100 parts by mass of the filler body 41, the crystal phase precipitated from the TiO ₂ particles 42 increases, which is necessary for sintering. As the amount of glass is reduced and closed pores cannot be efficiently discharged, the sinterability of the insulating substrate 1 is lowered. Therefore, the void ratio is increased, and the chemical resistance and the insulation reliability are lowered.

Here, in order to adhere the plurality of TiO ₂ particles 42 so as to cover the surface of the filler main body 41, a method of putting in a jet mill can be mentioned. Specifically, TiO ₂ particles 42 are charged into a jet mill at a rate of 15 to 100 grams with respect to 500 grams of the filler body 41, and rotated so as to have a peripheral speed of 80 to 90 m / s for 3 to 5 minutes. it is, adhesion amounts of the plurality of TiO ₂ particles relative to the filler main body 41 of the 100 parts by weight can be adjusted in the range of 3 to 10 parts by weight. Note that adhering so as to cover the surface means a state in which the surface does not exist in one place but is dispersed to some extent over the entire surface. However, it is not so strict that the same number of particles must exist in each region when divided into each region.

Next, glass powder is prepared. The glass powder has an average particle size of about 2.0 to 5.0 μm, 38 to 50 mol% Si in terms of SiO ₂ , 5 to 10 mol% B in terms of B ₂ O ₃ , and Al ₂ O _3. It contains 4 to 9 mol% of Al in terms of conversion, 25 to 38 mol% of Mg in terms of MgO, 1 to 3 mol% of Ca in terms of CaO, and 7 to 11 mol% of Ba in terms of BaO. For convenience, the oxide equivalent content of each component will be described as the oxide content.

Since Si 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 becomes poor, and firing at a low temperature of 850 ° C. to 900 ° C. is difficult. Become. Thereby, sinterability falls and a void will increase. On the other hand, when the content of SiO ₂ exceeds 50 mol%, cordierite having a low thermal expansion coefficient is likely to precipitate, and the thermal expansion coefficient of the insulating substrate 1 is lowered.

When 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 may be lowered. On the other hand, if the content of B ₂ O ₃ exceeds 10 mol%, there is an effect that the viscosity of the glass is lowered and it is easy to spread and wet, but the crystallization of the glass is inhibited and the amorphous phase is increased. The thermal expansion coefficient of the insulating substrate 1 is greatly reduced.

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. And various characteristics may be different. 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 rises and it becomes difficult to spread. Therefore, sinterability falls and a void will increase.

  When the content of MgO is less than 25 mol%, devitrification easily occurs. On the other hand, when the content of MgO exceeds 38 mol%, the crystallization start temperature becomes high, so that it can be densified (low void), but a large amount of cordierite is precipitated and the thermal expansion coefficient of the insulating substrate 1 is increased. May decrease.

  When the content of CaO is less than 1 mol%, the viscosity of the glass increases and the sinterability decreases. On the other hand, when the content of CaO exceeds 3 mol%, there is an effect of reducing the glass viscosity in the high temperature range and promoting densification, but a lot of cordierite is precipitated and the thermal expansion coefficient of the insulating substrate 1 is increased. May decrease.

  When the content of BaO is less than 7 mol%, the amount of BaO in the amorphous phase is decreased, and the thermal expansion coefficient of the amorphous phase may be lowered. On the other hand, when the BaO content exceeds 11 mol%, densification can be expected due to an increase in the crystallization start temperature, but the dielectric constant may increase.

Next, the glass ceramic green sheet containing a ceramic filler and glass powder is produced so that a filler main body may become a ratio of 30-40 mass% and glass powder 60-70 mass%. Specifically, an appropriate organic binder, organic solvent, or the like is added to a mixture of ceramic filler and glass powder, and then a glass ceramic green sheet is produced by a doctor blade method, a rolling method, or the like. Here, the ceramic filler and the glass powder are prepared so that the ratio of the filler main body and the glass becomes the above ratio in consideration of the ratio between the filler main body and the TiO ₂ particles attached thereto in the ceramic filler.

When the proportion of the filler body 41 is less than 30% by mass (the proportion of the glass powder exceeds 70% by mass), the glass amount (liquid phase) increases with respect to the specific surface area of the ceramic filler, so that the sinterability is improved. However, since the quartz is reduced, the thermal expansion coefficient of the insulating substrate 1 is lowered. Further, a large amount of Mg ₂ Al ₄ Si ₅ O ₁₈ (cordierite) with low thermal expansion is precipitated from the glass component (glass powder). On the other hand, when the proportion of the filler body 41 exceeds 40% by mass (the proportion of the glass powder is less than 60% by mass), the amount of glass (liquid phase) is insufficient with respect to the specific surface area of the ceramic filler. May decrease, and the densification of the insulating substrate 1 (void ratio of 5% or less) may not be promoted.

When TiO ₂ is contained in the glass powder, forsterite cannot be precipitated in an amount of 16% by mass or more, and the sinterability is lowered due to stabilization of the glass structure and an increase in viscosity. Even if TiO ₂ is used as a particle and mixed as a separate filler without adhering to the filler body 41 (quartz filler), the crystallization point of the glass is lowered at a low temperature without changing the glass transition point, softening point, and yield point. Since the glass is wet with respect to the filler main body 41 (quartz filler), the sinterability decreases and the number of voids increases.

  Next, a through-hole penetrating the glass ceramic green sheet is formed and filled with the through conductor paste, and the wiring layer conductor paste is applied to one main surface of the glass ceramic green sheet.

  Formation of the through hole in the glass ceramic green sheet is performed by a method such as punching, laser, or etching. The through-conductor paste filled in the through-hole is obtained by kneading an organic binder and an organic solvent into silver powder, copper powder or gold powder as a main component. Furthermore, it may contain inorganic components such as other metals, glass, oxides, carbides, nitrides and the like as long as they do not deteriorate the electrical resistance and thermal conductivity. For the filling, a screen printing method is used by using a metal mask in which holes are perforated at positions opposite to the through holes or an emulsion mesh screen mask. At this time, as a method for extruding the through-conductor paste through the mask, a method using a normal plate-like (or sword-shaped) squeegee made of polyurethane or the like may be used. A method of pressure injection may be used.

  The wiring layer conductor paste is applied by a screen printing method or the like. As the conductor paste for wiring layers, similar to the paste for through conductors, silver powder, copper powder, or gold powder as the main component, with organic binder and organic solvent kneaded, and if necessary, electrical resistance, thermal conductivity As long as it does not deteriorate the material, those containing other metals, glass, oxides, carbides, nitrides and other inorganic components are used. It should be noted that the wiring layer conductor paste used here may have a different viscosity from the through conductor paste filled in the through holes by means of, for example, varying the amount of the organic solvent. By making the viscosity lower than that of the paste for through conductors, the thickness can be reduced and an accurate pattern can be formed. On the other hand, the through-conductor paste can be prevented from dripping after filling by increasing the viscosity. Further, the wiring layer conductor paste and the through conductor paste may have different main components and subcomponents such as glass and inorganic filler.

  The glass ceramic green sheet is filled with the through conductor paste and coated with the wiring layer conductor paste, and then dried at 60 to 100 ° C. for about 1 to 3 hours.

  Next, a plurality of glass ceramic green sheets that have been filled with the paste for through conductors and coated with the conductor paste for wiring layers are laminated to produce a glass ceramic green sheet laminate. Specifically, a glass ceramic green sheet laminate is obtained by a method of laminating by pressurization using a thermocompression bonding method or a laminating aid.

  Finally, the glass ceramic green sheet laminate is fired.

  In firing, first, organic components such as an organic binder blended for molding are removed. The removal of the organic component is performed by holding at a temperature of 400 to 500 ° C. in an air atmosphere or 700 to 750 ° C. in a nitrogen atmosphere for 1 to 5 hours. And as this calcination, the calcination performed for 1-2 hours at the temperature of 850 ° C-900 ° C is made. The firing atmosphere is appropriately selected according to, for example, the metal type of the metallized wiring layer formed in the wiring substrate using the glass ceramic of the present invention as an insulating base. When copper is used as the metallized wiring layer in the wiring substrate, a non-oxidizing atmosphere is selected, and when silver is used, an oxidizing atmosphere is selected.

  By the manufacturing method of the multilayer wiring board described above, the void ratio of the insulating substrate is 5% or less, and the quartz content in the insulating substrate determined by the Rietveld analysis from the peak intensity of X-ray diffraction is 30 to 40% by mass, A multilayer wiring board having a forsterite content of 16 to 25% by mass can be obtained.

As the glass powder, a glass powder and a ceramic filler having the composition shown in Table 1 were prepared and weighed and mixed so that the ratio of the glass powder and the filler body was as shown in Table 1. Here, the adhesion amount (parts by mass) of TiO ₂ particles to 100 parts by mass of the filler body (SiO ₂ particles) in the ceramic filler is as shown in Table 1. Here, the average particle diameter of the glass powder is 3.9 μm, the average particle diameter of the filler body is 3.5 μm, the average particle diameter of the TiO ₂ particles attached so as to cover the filler body is 0.05 μm, and the specific surface area is 50 m. ² / g. In Table 1, sample No. 39 also shows a mixture of forsterite as a filler.

  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.

  Next, a 100 μm through hole was formed in the glass ceramic green sheet using a laser, and a through conductor paste mainly composed of copper powder was filled in the through hole by screen printing. Moreover, the conductor paste for wiring layers which has copper powder as a main component was apply | coated to the one main surface of the glass ceramic green sheet by screen printing.

  Then, the glass ceramic green sheet filled with the through conductor paste and coated with the wiring layer conductor paste is dried at 80 ° C. for 1 hour, and the obtained glass ceramic green sheets are laminated to form a glass ceramic green sheet laminate. The body was made.

  Finally, the glass ceramic green sheet laminate is 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. The main baking was performed at a temperature of 860 ° C. for 1 hour in a nitrogen atmosphere to obtain a sample of a multilayer wiring board.

  And the following measurements were performed with respect to the sample obtained by said method.

  First, the crystal phase in the insulating substrate was identified. This identification was performed by analyzing the measurement result (peak intensity ratio) of X-ray diffraction (XRD) 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, an X 2 in the range of 2θ = 10 ° or more and 80 ° or less measured by a diffractometer method by adding a standard sample of Cr ₂ O ₃ to a sample to be evaluated which was pulverized from an insulating substrate. respect ray diffraction pattern, by using RIETAN-2000 program, 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,} the evaluation sample The crystal structure and amount contained therein were evaluated. The amounts of quartz, forsterite, enstatite and cordierite obtained 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 4.5 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, the void ratio of the obtained insulating substrate was evaluated. The void ratio was determined by polishing the cross section of the obtained insulating substrate, observing with a scanning electron microscope, and analyzing the cross-sectional photograph. The results are shown in Table 2.

As shown in Table 1 and Table 2, samples within the scope of the present invention (Sample No. 2, No. 3, No. 6, No. 7, No. 10, No. 11, No. 14, No. 15) , No. 18, No. 21, No. 22, No. 27, No. 28, No. 29, No. 32, No. 33, No. 34, No. 37), 11.5 × 10 ^It can be seen that an insulating substrate satisfying high insulation reliability with a high coefficient of thermal expansion of ⁻⁶ / ° C. or higher and a low void ratio of 5% or less is obtained.

  On the other hand, sample No. which is outside the scope of the present invention. 1, No. 1 5, no. 9, no. 12, no. 13, no. In No. 17, since the composition of each component in the raw glass powder was outside the scope of the present invention, the properties of the glass such as viscosity and crystallization start temperature changed, and a void ratio of 5% or less could not be achieved.

In addition, sample No. which is outside the scope of the present invention. 23, no. 24, TiO ₂ particles are not attached to the filler body, and TiO ₂ is contained in the glass powder. Therefore, the glass structure is stabilized and the viscosity is increased, so that the sinterability is reduced and voids are formed. The rate of 5% or less could not be achieved.

Sample No. which is outside the scope of the present invention. 30, no. In No. 35, since the TiO ₂ particles adhered to the filler body in excess of 10% by mass, the crystal phase precipitated from the glass increased, and as a result, a void ratio of 5% or less could not be achieved.

  In addition, sample No. which is outside the scope of the present invention. In No. 36, since the filler main body contained more than 40% by mass, the amount of glass as a liquid phase was insufficient, and could not be densified. As a result, a void ratio of 5% or less could not be achieved.

  In addition, sample No. which is outside the scope of the present invention. In No. 39, since forsterite was mixed as a filler, a void ratio of 5% or less could not be achieved.

  Furthermore, sample no. 8, no. 9, no. 13, no. 20, no. 23, no. 24, no. 25, no. 26, no. 31, no. 38, no. No. 39 has a low content of quartz or forsterite having a high coefficient of thermal expansion, and is a sample no. 4, no. 16, no. 19, no. In No. 38, cordierite with a low coefficient of thermal expansion was precipitated, so that a coefficient of thermal expansion of 11.5 ppm / ° C. or more could not be achieved.

This is the sample No. 4, no. 8, no. 9, no. 13, no. 16, no. 19, no. In No. 20, it is because each component composition in the glass powder of a raw material is outside the scope of the present invention. Sample No. 23, no. In No. 24, TiO ₂ particles are not attached to the filler body, and TiO ₂ is contained in the glass powder. Sample No. 25, no. 26, no. In 31, it is due to the amount of the TiO ₂ particles adhering to the filler body is less than 3 wt%. Sample No. No. 38 has a small amount of raw material filler body (quartz). In No. 39, forsterite was mixed as a filler in the raw material.

It is a schematic sectional drawing which shows one Embodiment of the multilayer wiring board of this invention. It is a schematic diagram showing the state of adhesion of the filler body surfaces of the TiO ₂ particles.

Explanation of symbols

1 ... insulating substrate 11, 12, 13, 14 ... glass-ceramic insulating layers 2 ... through conductors 3 ... wiring layer 41 ... filler body 42 ... TiO ₂ particles

Claims (2)

Through an insulating substrate in which a plurality of glass ceramic insulating layers containing quartz as a main crystal and forsterite as a sub-crystal are laminated, the main component is at least one low-resistance conductor selected from the group consisting of Cu, Ag, and Au. In a multilayer wiring board provided with a conductor and a wiring layer, the void ratio of the insulating base is 5% or less, and the quartz content in the insulating base determined from a peak intensity of X-ray diffraction by Rietveld analysis is 30 to 30. A multilayer wiring board comprising 40% by mass, a forsterite content of 16 to 25% by mass, and a cordierite content of less than 1.0% by mass. Producing a ceramic filler by adhering a plurality of TiO ₂ particles at a ratio of 3 to 10 parts by mass with respect to 100 parts by mass of the filler body so as to cover the surface of the filler body made of quartz;
And 38～50Mol% of Si in terms of SiO _2, and 5 to 10 mol% of B in terms _of B 2 _{O 3,} and 4～9Mol% of Al in terms _{of Al} 2 _{O 3,} and 25～38Mol% of Mg in terms of MgO Preparing a glass powder containing 1 to 3 mol% Ca in terms of CaO and 7 to 11 mol% Ba in terms of BaO;
Producing a glass ceramic green sheet containing the ceramic filler and the glass powder so that the filler body is 30 to 40% by mass and the glass powder is 60 to 70% by mass;
Forming a through-hole penetrating the glass ceramic green sheet and filling with a paste for through conductor, and applying a wiring layer conductor paste to one main surface of the glass ceramic green sheet;
A step of producing a glass ceramic green sheet laminate by laminating a plurality of the glass ceramic green sheets filled with the through conductor paste and coated with the wiring layer conductor paste;
And a step of firing the glass-ceramic green sheet laminate.

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