JP5499766B2 - Glass ceramic substrate, method for manufacturing the same, and wiring substrate - Google Patents

Description

  The present invention relates to a glass ceramic substrate, a manufacturing method thereof, and a wiring substrate.

  As a wiring board used for an electronic device, a glass ceramic substrate made of a composition containing glass and a filler is known. A glass ceramic substrate is formed on a surface thereof to form a conductive pattern as a wiring substrate, which is mounted on an electronic device. As electronic devices become smaller and more functional, glass ceramic substrates are also required to be thinner.

  Since the glass ceramic substrate contains glass as a main component, it has a characteristic that it is vulnerable to impact and cracks are likely to occur. For this reason, attempts have been made to improve strength by blending ceramic fillers.

  For example, Patent Document 1 proposes increasing the degree of orientation of the ceramic filler in order to improve the strength of the glass ceramic substrate. Here, it is known that the ceramic filler having a high aspect ratio tends to be entangled with each other, so that the degree of orientation is lowered. For this reason, Patent Document 2 proposes that a ceramic filler having a small aspect ratio is blended to improve the orientation of the ceramic filler and provide a high-strength wiring board.

JP 2002-111210 A JP 2002-128564 A

  The glass ceramic substrate used for the wiring board is required to be further thinned as the electronic product is reduced in height. In addition, since the electrode structure is complicated with the complexity and miniaturization of the circuit board, the stress applied to the glass ceramic substrate is also increased. For this reason, a glass ceramic substrate having higher strength than before has been demanded. However, according to the study by the present inventors, it has been found that the glass ceramic substrate as proposed in Patent Documents 1 and 2 has insufficient strength and has a large variation in strength.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a glass ceramic substrate and a wiring substrate having sufficiently excellent strength. It is another object of the present invention to provide a method for producing a glass ceramic substrate capable of stably producing a glass ceramic substrate having sufficiently excellent strength.

  In the present invention, it contains glass and a plate-like alumina filler dispersed in the glass, the plate-like alumina filler has an aspect ratio of 20 or more, and an X-ray diffraction peak of the (104) crystal plane of the plate-like alumina filler. A glass ceramic substrate having an intensity ratio of an X-ray diffraction peak of the (006) crystal plane to 1.0 or more is provided.

  The glass ceramic substrate of the present invention has a sufficiently high strength and a high fracture toughness value. The present inventors infer one of the factors that can obtain such an effect as follows. In the present invention, when an alumina filler having a specific shape and aspect ratio is used with glass, two crystal planes are specified as the intensity ratio of the X-ray diffraction peak of the alumina filler, and the intensity ratio is set to a predetermined value. It is specified above. For this reason, it becomes possible to improve the orientation degree of the alumina filler having a high aspect ratio, which is considered to contribute to the improvement of the strength and fracture toughness values.

  Moreover, in this invention, it is preferable that the average plate diameter of a plate-like alumina filler is 2-8 micrometers. As a result, when forming wiring on the surface of the glass ceramic substrate while having sufficiently high strength, the glass capable of maintaining high reliability of the wiring substrate even when the wiring pitch is miniaturized. It can be a ceramic substrate.

  Further, the surface roughness Ra of the glass ceramic substrate of the present invention is preferably 0.3 μm or less. As a result, it is possible to improve the mountability when mounting as a wiring board.

  The present invention also provides a wiring board comprising the glass ceramic substrate and a conductor on the glass ceramic substrate. Since such a wiring board includes the glass ceramic substrate having the above-described characteristics, it has a sufficiently excellent strength.

  In the present invention, a slurry containing glass powder and a plate-like alumina filler having an aspect ratio of 20 or more is applied onto a substrate to form a film, and a film forming process for producing a green sheet, and firing the green sheet And a firing step of obtaining a glass ceramic substrate having an intensity ratio of the X-ray diffraction peak of the (006) crystal plane to the X-ray diffraction peak of the (104) crystal plane of the plate-like alumina filler is 1.0 or more. A method for producing a glass ceramic substrate is provided.

  The glass ceramic substrate manufacturing method of the present invention uses glass and an alumina filler having a specific shape and aspect ratio. At the same time, two crystal planes are specified as the intensity ratio of the X-ray diffraction peak of the alumina filler, and a glass ceramic substrate in which the intensity ratio of the peaks is a predetermined value or more is manufactured. For this reason, it becomes possible to improve the orientation degree of the alumina filler having a high aspect ratio, which is considered to contribute to the improvement of the strength and fracture toughness values.

  In the firing step in the method for producing a glass-ceramic substrate of the present invention, it is preferable to fire a laminate having a green sheet and another green sheet having a smaller thermal shrinkage than the green sheet so as to sandwich the green sheet. . Thereby, the shrinkage of the green sheet serving as the glass ceramic substrate is suppressed, and the disorder of orientation caused by the variation in shrinkage can be suppressed. As a result, a glass ceramic substrate having a sufficiently high strength can be obtained.

  According to the present invention, it is possible to provide a glass ceramic substrate having a sufficiently excellent strength and a wiring substrate including such a glass ceramic substrate. Moreover, the manufacturing method of the glass-ceramics substrate which can manufacture the glass-ceramics substrate which has the fully outstanding intensity | strength stably can be provided.

1 is a schematic cross-sectional view showing a preferred embodiment of a wiring board according to the present invention. It is a top view which shows an example of the plate-like alumina filler contained in the glass-ceramics substrate which is suitable embodiment of this invention. It is a side view which expands and shows a part of side surface in the glass ceramic substrate which is suitable embodiment of this invention. 1 is an X-ray diffraction chart of a glass ceramic substrate which is a preferred embodiment of the present invention. It is process sectional drawing which shows typically the manufacturing method of the glass-ceramics substrate which is suitable embodiment of this invention. 18 is an X-ray diffraction chart of a glass ceramic substrate of Example 15. FIG. 18 is an X-ray diffraction chart of a glass ceramic substrate of Example 17. FIG. 10 is an X-ray diffraction chart of a glass ceramic substrate of Comparative Example 3. 10 is an X-ray diffraction chart of a glass ceramic substrate of Comparative Example 5. FIG.

  In the following, preferred embodiments of the present invention will be described with reference to the drawings as the case may be.

  FIG. 1 is a schematic cross-sectional view of the wiring board of the present embodiment. A wiring board 10 shown in FIG. 1 has a laminated structure in which glass ceramic substrates 11a, 11b, 11c and 11d (hereinafter collectively referred to as glass ceramic substrates 11a to 11d) are laminated in this order. Further, the wiring board 10 is opposite to the inner conductor 13 provided between the glass ceramic substrates adjacent in the vertical direction in FIG. 1 and the 11b (11c) side of the glass ceramic substrate 11a (11d) which is the outermost layer. And a via conductor 12 that electrically connects the inner conductor 13 and the surface conductor 14 to each other.

  Each of the glass ceramic substrates 11a to 11d contains glass and a plate-like alumina filler dispersed in the glass. The content of the plate-like alumina filler is preferably 20 to 35% by volume, more preferably 22.5 to 35% by volume, with respect to the total amount of glass and plate-like alumina filler. Hereinafter, each component will be described in detail.

<Plate-like alumina filler>
The glass ceramic substrates 11a to 11d of the present embodiment include a plurality of plate-like alumina fillers. The average plate diameter of the plate-like alumina filler is preferably 2 to 10 μm, more preferably 2 to 8 μm. When the average plate diameter of the plate-like alumina filler is less than 2 μm, high orientation of the plate-like alumina filler tends to be difficult to obtain. On the other hand, if the average plate diameter of the plate-like alumina filler exceeds 10 μm, the electrical characteristics of electronic components and the like may be affected when the wiring pitch of the wiring board is small.

  The average thickness of the plate-like alumina filler is preferably 0.4 μm or less, more preferably 0.03 to 0.3 μm, from the viewpoint of further improving the strength of the glass ceramic substrates 11a to 11d. If the average thickness of the plate-like alumina filler is reduced, it becomes possible to increase the number of plate-like alumina fillers contained in the glass ceramic substrates 11a to 11d with the same content, thereby improving the strength of the glass ceramic substrates 11a to 11d. Can be made. On the other hand, when the average thickness of the plate-like alumina filler exceeds 0.3 μm, the good orientation of the plate-like alumina filler tends to be impaired.

  The average aspect ratio of the plate-like alumina filler is preferably 20 or more, more preferably 25 to 70, from the viewpoint of further improving the strength of the glass ceramic substrates 11a to 11d. When the average aspect ratio of the plate-like alumina filler is less than 20, good orientation of the plate-like alumina filler tends to be impaired.

  FIG. 2 is a top view showing an example of a plate-like alumina filler contained in the glass ceramic substrate of the present embodiment. FIG. 2 shows the plate surface shape of the plate-like alumina filler 20. That is, the plate surface of the plate-like alumina filler 20 has an octagonal shape. When the plate surface of the plate-like alumina filler 20 is not a regular octagon as shown in FIG. 2, the plate diameter of the plate-like alumina filler 20 can be obtained as an average value of the major axis y and the minor axis x on the plate surface. That is, the plate diameter of the plate-like alumina filler 20 can be obtained as an average value of the long side and the short side of the smallest rectangle inscribed in the plate-like alumina filler 20. When the smallest square inscribed in the plate-like alumina filler 20 is a square, the length of one side is the plate diameter.

  The thickness of the plate-like alumina filler 20 is the maximum length in the direction perpendicular to the plate surface. The average plate diameter and average thickness are respectively the arithmetic average values of the measured values of the plate diameter and thickness of 500 plate-like alumina fillers randomly extracted from the electron microscope image. The average aspect ratio is calculated by (average plate diameter) / (average thickness).

  The plate-like alumina filler contained in the glass ceramic substrate of the present embodiment has a planar shape viewed from a direction perpendicular to the plate surface as shown in FIG. 2, such as a circle, an ellipse, or a polygon that approximates a circle or an ellipse. Those having a small anisotropic shape are preferred. From the viewpoint of improving the strength of the glass ceramic substrates 11a to 11d, the planar shape of the plate-like alumina filler is preferably a hexagon, more preferably a regular hexagon.

  FIG. 3 is an enlarged side view showing a part of the side surface of the glass ceramic substrate 11a of the present embodiment. As shown in FIG. 3, the plate-like alumina filler 20 dispersed in the glass 22 of the glass ceramic substrate has a plate surface facing substantially the same direction and substantially parallel to the surface A. Thus, the plate-like alumina filler 20 has a good orientation. The quality of this orientation can be judged by the intensity ratio of the peaks of the (104) crystal plane and the (006) crystal plane determined by X-ray diffraction measurement using CuKα rays.

(104) crystal face of the plate-like alumina filler and (006) intensity ratio of X-ray diffraction peak in the crystal plane, (104) crystal face and (006) peak intensity of the area reference crystal plane, respectively _{I (006)} and when the _{I (104),} can be determined the ratio of _{I (006)} with respect to _{I (104),} i.e. by equation _{I (006) / I (104} ).

I ₍₀₀₆₎ / I ₍₁₀₄₎ (hereinafter referred to as peak intensity ratio α) of the plate-like alumina filler of the present embodiment is 1.0 or more. The plate-like alumina filler having such a peak intensity ratio α has a good orientation in the glass ceramic substrates 11a to 11d. The peak intensity ratio α is preferably 1.5 or more, more preferably 2.0 or more, and even more preferably 3.0 or more, from the viewpoint of a glass ceramic substrate having further excellent strength. As the peak intensity ratio α increases, the orientation of the plate surface of the plate-like alumina filler becomes more uniform and the orientation becomes better. Thus, the glass-ceramic substrate of this embodiment has excellent strength and high toughness because the orientation of the plate surface of the plate-like alumina filler is almost uniform and the orientation is good. The peak intensity ratio α is not particularly limited, but practically the upper limit is about 20.

  FIG. 4 is a chart showing X-ray diffraction measurement results of the glass ceramic substrate of the present embodiment. A chart A in FIG. 4 is an X-ray diffraction chart measured by irradiating the surface A of the glass ceramic substrate 11a in FIG. 3 with X-rays using a commercially available X-ray diffractometer. A chart B in FIG. 4 is an X-ray diffraction chart measured by irradiating the surface B of the glass ceramic substrate 11a in FIG. 3 with X-rays using a commercially available X-ray diffractometer.

  Chart A shows peaks of the (104) crystal plane and the (006) crystal plane more clearly than Chart B. The peak intensity ratio α of the present embodiment is a value calculated from the peak of the chart A measured by irradiating the surface A, that is, the surface substantially parallel to the plate surface of the plate-like alumina filler 20 with X-rays. Since chart A is an X-ray diffraction peak measured by irradiating X-rays on a plane substantially parallel to the plate surface of the plate-like alumina filler 20, the (104) crystal plane of the plate-like alumina filler 20 and (006) Crystalline peaks are clearly shown. Therefore, the peak intensity ratio α can be calculated with high accuracy from the peak intensity of each peak. As described above, in this embodiment, in order to improve the orientation of the plate-like alumina filler 20 having a specific aspect ratio, a surface to be irradiated with X-rays is specified, and an optimum crystal plane is determined according to the surface. Has been identified. As a result, the strength of the glass ceramic substrate can be sufficiently increased, and variations in strength can be sufficiently reduced. In Chart B, since the plate-like alumina filler 20 has a higher aspect ratio, the peaks of the (104) crystal plane and the (006) crystal plane are less clear than in Chart A. For this reason, it is difficult to calculate an accurate peak intensity ratio α from the X-ray diffraction peak of Chart B.

  In addition, although the (110) crystal plane is considered as another crystal plane showing the orientation of the plate-like alumina filler, this (110) crystal plane is not detected in Chart A. Therefore, it is considered that the orientation of the plate-like alumina filler cannot be defined by the (110) crystal plane.

  The glass ceramic substrates 11 a to 11 d may further contain a ceramic filler other than the plate-like alumina filler 20. Examples of the ceramic filler other than the plate-like alumina filler include at least one selected from the group consisting of magnesia, spinel, silica, mullite, forsterite, steatite, cordierite, strontium feldspar, quartz, zinc silicate, zirconia and titania. And spherical or plate-like fillers formed of the above materials. Moreover, the glass ceramic substrates 11a to 11d may contain spherical alumina. From the viewpoint of further increasing the strength of the glass ceramic substrates 11a to 11d, the ratio of the plate-like alumina filler is preferably 80% by volume or more of the total ceramic filler.

<Glass>
Examples of the material of the glass 22 included in the glass ceramic substrates 11a to 11d include glass powder made of at least one of (1) an amorphous glass material and (2) a crystallized glass material. (2) A crystallized glass material is a material in which a number of fine crystals are precipitated in a glass component during heating and firing, and is also referred to as glass ceramic.

The glass 22 is preferably formed using (2) a crystallized glass material among (1) an amorphous glass material and (2) a crystallized glass material. (2) As a crystallized glass material, for example, (i) glass containing SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ and an alkaline earth metal oxide, and (ii) SiO ₂ , CaO, MgO, Diopside crystal glass containing Al ₂ O ₃ and CuO can be used.

The suitable composition of the glass of (i) and the suitable composition of the glass 22 in the glass ceramic substrates 11a-11d at the time of using the glass of (i) are demonstrated. The glass 22 preferably contains SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ and an alkaline earth metal oxide. The content of SiO ₂ is preferably 46 to 60% by mass, and more preferably 47 to 55% by mass based on the total amount of glass 22. When the content of SiO ₂ in the glass of (i) is less than 46% by mass, vitrification tends to be difficult. On the other hand, when the content of SiO ₂ in the glass of (i) exceeds 60% by mass, the melting point becomes high and low-temperature sintering tends to be difficult.

The content of B ₂ O ₃ is preferably 0.5 to 5% by mass, more preferably 1 to 3% by mass, based on the total amount of the glass 22. When the content of B ₂ O ₃ in the glass 22 exceeds 5% by mass, the moisture resistance tends to decrease. On the other hand, when the content of B ₂ O ₃ in the glass 22 is less than 0.5% by mass, the vitrification temperature tends to increase and the density tends to decrease.

The content of Al ₂ O ₃ is preferably 6 to 17.5% by mass, more preferably 7 to 16.5% by mass, based on the total amount of the glass 22. If the content of Al ₂ O ₃ in the glass 22 is less than 6% by mass, sufficiently excellent strength may be impaired. On the other hand, when the content of Al ₂ O ₃ in the glass 22 exceeds 17.5% by mass, vitrification tends to be difficult.

  The content of the alkaline earth metal oxide is preferably 25 to 45 mass%, more preferably 30 to 40 mass%, based on the total amount of the glass 22. Examples of the alkaline earth metal oxide include MgO, CaO, BaO, and SrO. These alkaline earth metal oxides may contain only one kind or two or more kinds. Among alkaline earth metal oxides, it is preferable to contain a combination of SrO and other alkaline earth metal oxides. When SrO is used in combination with at least one selected from the group consisting of CaO, MgO and BaO, the viscosity of the molten glass is lowered, and the degree of freedom of the sintering temperature can be increased. For this reason, manufacture of the glass ceramic substrates 11a-11d can be made easy.

  The content of SrO with respect to the total amount of the alkaline earth metal oxide is preferably 60% by mass or more, more preferably 80% by mass or more. If this content is less than 60% by mass, the difference in thermal expansion coefficient between the glass 22 and the plate-like alumina filler 20 tends to increase, and the strength of the glass ceramic substrates 11a to 11d tends to decrease.

  The total content of CaO, MgO and BaO with respect to the total amount of the alkaline earth metal oxide is preferably 1% by mass or more. The content of CaO and MgO with respect to the total amount of the alkaline earth metal oxide is preferably 0.2% by mass or more, and more preferably 0.5% by mass or more. The content of CaO with respect to the total amount of the alkaline earth metal oxide is preferably less than 10% by mass. The content of MgO with respect to the total amount of the alkaline earth metal oxide is preferably 4% by mass or less. When the content of CaO and MgO is larger than the above value, the thermal expansion coefficient becomes too small, the strength of the glass ceramic substrates 11a to 11d tends to decrease, and the control of the crystallinity of the glass tends to be difficult. is there. From the viewpoint of achieving both the ease of production of the glass ceramic substrates 11a to 11d and the strength of the glass ceramic substrate, the total content of CaO and MgO with respect to the total amount of the alkaline earth metal oxide is preferably less than 10% by mass. . The content of CaO with respect to the total amount of the alkaline earth metal oxide is preferably 5% by mass or less.

  The content of BaO with respect to the total amount of the alkaline earth metal oxide is preferably 5% by mass or less. When this content exceeds 5% by mass, the dielectric constant tends to increase.

  Next, the suitable composition of the glass 22 in the glass-ceramic substrates 11a-11d at the time of using the crystal glass of (ii) and the crystal glass of (ii) is demonstrated. The crystal glass of (ii) precipitates diopside crystal glass as a main crystal by firing.

In the diopside crystal glass, SiO ₂ is a glass network former and a constituent component of the diopside crystal. The content of SiO ₂ is preferably 40 to 65% by mass, more preferably 45 to 65% by mass, based on the total amount of diopside crystal glass. If the content of SiO ₂ is less than 40% by mass, vitrification tends to be difficult. On the other hand, when the content of SiO ₂ exceeds 65% by mass, the density tends to decrease.

  In the diopside crystal glass, CaO is a constituent component of the diopside crystal. The content of CaO is preferably 20 to 35% by mass and more preferably 25 to 30% by mass with respect to the total amount of diopside crystal glass. When the CaO content is less than 20% by mass, the dielectric loss tends to increase. On the other hand, when the CaO content exceeds 35% by mass, vitrification tends to be difficult.

  In the diopside crystal glass, MgO is a constituent component of the diopside crystal. The content of MgO is preferably 11 to 30% by mass, more preferably 12 to 25% by mass, based on the total amount of diopside crystal glass. If the content of MgO is less than 11% by mass, crystals tend to hardly precipitate. On the other hand, when the content of MgO exceeds 30% by mass, vitrification tends to be difficult.

In the diopside crystal glass, Al ₂ O ₃ is a component that adjusts the crystallinity of the glass. The content of Al ₂ O ₃ is preferably 0.5 to 10% by mass and more preferably 1 to 5% by mass with respect to the total amount of diopside crystal glass. When the content of Al ₂ O ₃ is less than 0.5% by mass, the crystallinity becomes too strong and glass forming tends to be difficult. On the other hand, when the content of Al ₂ O ₃ exceeds 10% by mass, diopside crystals tend to be difficult to precipitate.

  In the diopside crystal glass, CuO is a component that gives electrons to Ag and suppresses diffusion into glass ceramics. The content of CuO is preferably 0.01 to 1.0 mass% with respect to the total amount of the diopside crystal glass component. When the content of CuO is less than 0.01% by mass, the above effects tend not to be sufficiently exhibited. On the other hand, when the CuO content exceeds 1.0 mass%, the dielectric loss tends to be too large.

In the diopside crystal glass component, SrO, ZnO, and TiO ₂ are components added to facilitate vitrification. The content of each component with respect to the total amount of the diopside crystal glass component is preferably 0 to 10% by mass, and more preferably 0 to 5%. When each of these components exceeds 10% by mass, the crystallinity becomes weak, the amount of diopside deposited decreases, and the dielectric loss tends to increase.

  The diopside crystal glass component may contain components other than the above components as long as the characteristics such as dielectric loss are not impaired.

  Of the glasses (i) and (ii), the glass 22 in the glass ceramic substrates 11a to 11d is preferably formed using the crystal glass (ii) from the viewpoint of obtaining a further excellent strength.

  The surface roughness Ra of the glass ceramic substrates 11a to 11d of the present embodiment is preferably 0.5 μm or less, more preferably 0.4 μm, from the viewpoint of further increasing the strength and improving the mountability to electronic components. Or less, more preferably 0.3 μm or less. The surface roughness Ra of the glass ceramic substrates 11a to 11d can be changed by adjusting the particle size of the glass powder used as a raw material. The average particle diameter (D50) of the glass powder is preferably 2 μm or less, more preferably 1.8 μm or less. In addition, the average particle diameter in this specification is a volume average particle diameter (d (50)) measured using a commercially available laser diffraction type particle size distribution measuring apparatus.

  As mentioned above, although preferred embodiment of the glass-ceramics board | substrate of this invention and a wiring board provided with the same was described, this invention is not limited to the said embodiment. For example, the wiring board may be composed of a single glass ceramic substrate. Further, only one of the plurality of laminated glass ceramic substrates may be used as the glass ceramic substrate of the above embodiment. Further, the number of glass ceramic substrates provided on the wiring board is not limited.

  Next, a preferred embodiment of the method for producing a glass ceramic substrate of the present invention will be described with the wiring substrate 10 as an example. FIG. 5 is a process cross-sectional view for explaining a method of manufacturing the wiring substrate 10 shown in FIG.

  In the method for manufacturing a glass ceramic substrate of the present embodiment, first, as shown in FIG. 5A, a green sheet for a substrate on which at least one of a via conductor pattern 2, an internal conductor pattern 3, and a surface conductor pattern 4 is formed. 1a to 1d are prepared.

  The substrate green sheets 1a to 1d contain glass and a plate-like alumina filler dispersed in the glass. These green sheets 1a to 1d for substrates can be formed by the following procedure.

  First, the plate-like alumina filler 20 is prepared. The plate-like alumina filler 20 is, for example, a reaction step in which an aluminate and an acidic aluminum salt are reacted in a state containing water to obtain a mixture containing alumina and / or an alumina hydrate and a neutralized metal salt, It can obtain by the manufacturing method which has a baking process which bakes this mixture at 1000-1600 degreeC.

  In the reaction step, first, sodium hydroxide is dissolved in water to prepare a sodium hydroxide solution. In this sodium hydroxide solution, metallic aluminum and disodium hydrogen phosphate are mixed and stirred to prepare a mixed solution in which metallic aluminum and disodium hydrogen phosphate are dissolved. An aluminum sulfate aqueous solution is added to the mixed solution while stirring until the pH becomes 6 to 8, and a cloudy gel-like mixture (a mixture containing alumina and / or alumina hydrate and neutralized metal salt) is obtained. Thereafter, the mixture is dried to remove moisture.

  In the firing step, the dried mixture is fired at 1000 to 1600 ° C. for 2 to 8 hours to obtain a fired product. Water is added to the obtained fired product for washing and filtration, and the obtained solid content is dried. Through the above steps, a plate-like alumina filler 20 having a predetermined size can be obtained.

  The plate-like alumina filler 20 is mixed with, for example, glass powder and an organic vehicle containing a binder, a solvent, a plasticizer, a dispersant, and the like to prepare a slurry-like dielectric paste. Here, in order to improve the orientation of the plate-like alumina filler, it is necessary to sufficiently disperse the plate-like alumina filler in the dielectric paste. On the other hand, it is necessary to sufficiently prevent the plate-like alumina filler 20 from being damaged during mixing. Therefore, from the viewpoint of improving the dispersibility of the plate-like alumina filler 20 while preventing the plate-like alumina filler 20 from being damaged, the mixing is performed using a ball mill rather than a mixing device using a medium (for example, a bead mill). Is preferred. Moreover, it is preferable to perform mixing over time from a viewpoint of reducing the impact at the time of mixing. Specifically, the mixing time is preferably 40 hours or longer.

  The content of the plate-like alumina filler 20 in the dielectric paste is preferably 22.5 to 32.5% by volume. If the dispersibility of the plate-like alumina filler is insufficient, the good orientation of the plate-like alumina filler in the glass ceramic substrate tends to be impaired.

  Examples of the binder include polyvinyl butyral resin and methacrylic acid resin. Examples of the plasticizer include dibutyl phthalate. Examples of the solvent include toluene and methyl ethyl ketone.

  The prepared dielectric paste is formed into a film by a doctor blade method or the like on a support such as a polyethylene terephthalate (PET) sheet. Thus, the substrate green sheets 1a to 1d can be formed on the support. By performing film formation by the doctor blade method, the plate surface of the plate-like alumina filler can be oriented so as to be substantially parallel (horizontal direction) to the main surface of the substrate green sheet. Thereby, a glass ceramic substrate having a sufficiently excellent strength can be formed.

  Next, conductor patterns (wiring patterns, electrode pads, via holes, etc.) are formed on the substrate green sheets 1a to 1d. Specifically, a through-hole (via hole) is formed at a predetermined position of the substrate green sheets 1a to 1d, and the via conductor pattern 2 is formed by filling the conductor paste therein. Also, a conductor paste is printed in a predetermined pattern on the surface of the substrate green sheets 1b and 1c which are the inner layers, and the inner conductor pattern 3 is formed. Further, the surface conductor pattern 4 is formed on the substrate green sheets 1a and 1d arranged on the outermost side. Electronic elements (inductors, capacitors, etc.) may be formed on the substrate green sheets 1a to 1d as necessary.

  The conductive paste used for forming the conductor pattern can be prepared, for example, by kneading a conductive material made of various conductive metals or alloys such as Ag, Ag-Pd alloy, Cu, Ni, and the organic vehicle. The organic vehicle used for the conductive paste contains a binder and a solvent as main components. There is no restriction | limiting in particular in the compounding ratio of a binder, a solvent, and an electrically-conductive material, For example, 1-15 mass% of binders and 10-50 mass% of solvents can be mix | blended with respect to an electrically-conductive material. You may add the additive selected from various dispersing agents, a plasticizer, etc. to an electrically conductive paste as needed.

  Next, as shown in FIG. 5B, the substrate green sheets 1a, 1b, 1c and 1d are laminated in this order to obtain a laminate. A pair of shrinkage-suppressing green sheets 5 serving as a constraining layer is disposed so as to sandwich the laminated body in the laminating direction. By sandwiching the laminate composed of the substrate green sheets 1a to 1d with the shrinkage-suppressing green sheet 5, it is possible to suppress shrinkage in the in-plane direction (direction perpendicular to the lamination direction) of the laminate during firing described later. it can.

  Moreover, by suppressing the shrinkage | contraction of the in-plane direction of a laminated body in this way, disorder of the orientation of the plate-like alumina filler which arises by shrinkage | contraction dispersion | variation can be reduced. That is, it is possible to maintain the good orientation of the plate-like alumina filler that has been oriented before firing. Therefore, a sintered body having a high degree of orientation can be obtained, and a glass ceramic substrate with further excellent strength can be obtained.

  Examples of the material (hereinafter referred to as “shrinkage suppressing material”) used for the shrinkage suppressing green sheet 5 serving as the constraining layer include tridymite, cristobalite, quartz, fused silica, alumina, mullite, zirconia, aluminum nitride, boron nitride, Examples include magnesium oxide, silicon carbide, and calcium carbonate.

  The shrinkage suppression material preferably contains a material that does not shrink at the firing temperature of the substrate green sheets 1a to 1d. Of the above-mentioned materials, tridymite is preferable because it has a function as a constraining layer and can be easily peeled. When tridymite is used, after the laminate is fired, the shrinkage-suppressing green sheet 5 is naturally peeled due to the difference in thermal expansion. In order to further improve the peelability, the constraining layer preferably has a laminated structure in which a layer made of calcium carbonate is laminated on a layer made of tridymite.

  Next, as shown in FIG. 5C, the laminate (temporary stack) in which the shrinkage-suppressing green sheets 5 are arranged on both sides is pressed. By performing baking after pressing, the substrate green sheets 1a to 1d become glass ceramic substrates 11a to 11d, and the via conductor pattern 2 in the via hole becomes the via conductor 12, as shown in FIG. Further, the inner conductor pattern 3 becomes the inner conductor 13, and the surface conductor pattern 4 becomes the surface conductor 14.

  Next, as shown in (e) of FIG. 5, the shrinkage-suppressing green sheet 5 is peeled from the glass ceramic substrates 11a and 11b. Through the above steps, the glass ceramic substrates 11a to 11d and the wiring substrate 10 including the glass ceramic substrates 11a to 11d can be obtained. You may perform the measurement process which performs at least 1 X-ray-diffraction measurement of 11a-11d of a glass ceramic substrate after a baking process.

  As described above, the method for manufacturing the glass ceramic substrates 11a to 11d and the wiring substrate 10 shown in FIG. 1 has been described. However, the method for manufacturing the glass ceramic substrate and the wiring substrate of the present invention is not limited to the method described above. For example, in the above-described manufacturing method, the shrinkage suppressing green sheet 5 is disposed and the laminate is fired. However, the laminate is fired without the shrinkage suppressing green sheet 5 being disposed, and the glass ceramic substrate and A wiring board may be manufactured.

  The contents of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

( Reference Example 1)
Preparation of glass ceramic substrate]
A glass powder A (a crystallized glass powder with SiO ₂ , CaO, MgO, Al ₂ O ₃ and CuO as main components and depositing diopside) and a plate-like alumina filler were prepared. Table 1 shows the average plate diameter, average thickness, and average aspect ratio of the plate-like alumina filler.

  An organic vehicle was prepared by mixing 19.4 g of acrylic resin, 59.1 g of toluene, 3 g of ethanol, and 6.5 g of a plasticizer (butyl butyl phthalyl glycolate). And the glass powder A, the plate-like alumina filler, and the prepared organic vehicle were mix | blended, and it mixed for 72 hours using the ball mill, and prepared the dielectric paste.

  The prepared dielectric paste was formed on a polyethylene terephthalate film by a doctor blade method to form a plurality of green sheets for a substrate. A plurality of green sheets for a substrate were laminated and pressed at 74 MPa, and then fired at 900 ° C. for 1 hour in the air to obtain a multilayered glass ceramic substrate. The total thickness of the fired glass ceramic substrate was 0.2 mm, and the content of the plate-like alumina filler in the glass ceramic substrate was as shown in Table 1.

Next, the X-ray diffraction measurement of the glass ceramic substrate was performed using a commercially available X-ray diffractometer. The measurement surface was the surface A in FIG. In the obtained X-ray diffraction chart, the area-based peak intensities (I ₀₀₆ , I ₁₀₄ ) of the (006) crystal plane and (104) crystal plane of the plate-like alumina filler were determined, and the ratio of I _{006 to} I ₁₀₄ was determined. (I ₀₀₆ / I ₁₀₄ ) was determined (referred to as peak intensity ratio 1). The results were as shown in Table 1.

[Evaluation of glass ceramic substrate]
In accordance with JIS C2141, a three-point bending strength test of the glass ceramic substrate produced as described above was performed. Specifically, one side of the glass ceramic substrate is supported at two points, and a load is gradually applied to an intermediate position between the two points on the opposite side to measure the load when the glass ceramic substrate is cut. Based on this, the three-point bending strength (MPa) was calculated. The bending strength was measured at 30 points to determine an average value (average bending strength). The results are shown in Table 1.

( Reference Examples 2 to 6 Example 7 and Comparative Example 2)
As shown in Table 1, a glass ceramic substrate was prepared in the same manner as in Reference Example 1 except that plate-like alumina fillers having different sizes and shapes were used, and X-ray diffraction measurement was performed. Then, evaluation was performed in the same manner as in Reference Example 1. Table 1 shows the peak intensity ratio 1 and evaluation results of X-ray diffraction.

It should be noted that the embodiment 11 and Reference Example 5, subjected to X-ray diffraction measurement of the obtained laminated body by laminating a plurality of green sheets for a _substrate, the ratio of _{I 006} for _{I 104 (I 006 / I 104} ) (Referred to as peak intensity ratio 2). The results were as shown in Table 1.

(Examples 7 to 12 and Comparative Example 2)
A plurality of green sheets were produced in the same manner as in Reference Examples 1 to 6 and Comparative Example 1. A laminate was obtained by laminating a plurality of substrate green sheets. A pair of shrinkage-suppressing green sheets containing tridymite were laminated so as to sandwich the laminate in the lamination direction, and pressed at 74 MPa. Then, it baked at 900 degreeC in air | atmosphere for 1 hour, and obtained the glass-ceramic board | substrate of a multilayer structure. The thickness of the fired glass ceramic substrate was 0.2 mm, and the content of the plate-like alumina filler in the glass ceramic substrate was as shown in Table 1.

X-ray diffraction measurement and evaluation were performed in the same manner as in Reference Examples 1 to 6 and Comparative Example 1. X-ray diffraction peak intensity ratio 1 and evaluation results were as shown in Table 1.

(Examples 13 to 18, Comparative Example 3)
As shown in Table 2, the size and blending amount of the plate-like alumina filler were changed, and the glass powder B (SiO ₂ , CaO, MgO, Al ₂ O ₃ and CuO as main components instead of the glass powder A, Glass ceramic substrates of Examples 13 to 18 and Comparative Example 3 were produced in the same manner as in Example 1 except that crystallized glass powder that precipitates diopside was used. And it carried out similarly to Example 1, and performed the X-ray-diffraction measurement and evaluation. The X-ray diffraction peak intensity ratio 1 and the evaluation results are shown in Table 2.

About Example 16 and Comparative Example 3, the fracture toughness value (K _IC ) was measured based on JIS-R-1607. As a result, it was confirmed that Example 16 had a higher fracture toughness value. It was confirmed that the higher the orientation of the plate-like alumina filler, the higher the fracture toughness value.

(Example 19)
A glass ceramic substrate was prepared in the same manner as in Example 14 except that the mixing time using the ball mill after blending the glass powder B, the plate-like alumina filler, and the prepared organic vehicle was changed from 72 hours to 48 hours. did. And it carried out similarly to Example 14, and performed X-ray-diffraction measurement and evaluation. X-ray diffraction peak intensity ratio 1 (I ₀₀₆ / I ₁₀₄ ) and evaluation results are shown in Table 2.

(Comparative Example 4)
A glass ceramic substrate was produced in the same manner as in Example 14 except that the mixing time using the ball mill after blending the glass powder B, the plate-like alumina filler, and the prepared organic vehicle was changed from 72 hours to 24 hours. did. And it carried out similarly to Example 14, and performed X-ray-diffraction measurement and evaluation. X-ray diffraction peak intensity ratio 1 (I ₀₀₆ / I ₁₀₄ ) and evaluation results are shown in Table 2.

  FIG. 6 is an X-ray diffraction chart of the glass-ceramic substrate of Example 15. As shown in FIG. 6, in the X-ray diffraction chart of Example 15, clear peaks derived from the (006) crystal plane and the (104) crystal plane could be confirmed. On the other hand, the peak of the (110) crystal plane could not be confirmed.

  FIG. 7 is an X-ray diffraction chart of the glass ceramic substrate of Example 17. As shown in FIG. 7, in the X-ray diffraction chart of Example 17, clear peaks derived from the (006) crystal plane and the (104) crystal plane could be confirmed. On the other hand, the peak of the (110) crystal plane could not be confirmed.

  From the X-ray diffraction charts of FIGS. 6 and 7, it was confirmed that in the case of a plate-like alumina filler having a high aspect ratio, the orientation of the plate-like alumina filler cannot be determined from the X-ray diffraction peak of the (110) crystal plane. .

FIG. 8 is an X-ray diffraction chart of the glass ceramic substrate of Comparative Example 3. In FIG. 8, the peaks of the (006) crystal plane, the (104) crystal plane, and the (110) crystal plane were confirmed. From the intensity of each of these peaks, I ₀₀₆ / (I ₁₁₀ + I ₀₀₆ ) was calculated to be 0.8.

(Examples 20 to 22)
A glass ceramic substrate was produced in the same manner as in Example 11 except that glass powder B having an average particle size shown in Table 3 was used. And it carried out similarly to Example 11, and performed the X-ray-diffraction measurement and evaluation. The X-ray diffraction peak intensity ratio 1 and the evaluation results are shown in Table 3. In addition, the arithmetic average roughness (Ra) at any ten points on the surface of the glass ceramic substrate was measured using a surface roughness meter according to JIS B0601 (1994). The measurement results were as shown in Table 3.

( Reference Examples 23 and 24)
A glass ceramic substrate was produced in the same manner as in Reference Example 4 except that the content of the alumina filler in the glass ceramic substrate was changed as shown in Table 3 by changing the blending amount of the plate-like alumina filler. And it carried out similarly to the reference example 4, and performed the X-ray-diffraction measurement and evaluation. The X-ray diffraction peak intensity ratio 1 and the evaluation results are shown in Table 3.

(Examples 25 and 26)
A glass ceramic substrate was produced in the same manner as in Example 10 except that the amount of the alumina filler was changed and the content of the alumina filler was changed as shown in Table 3. And it carried out similarly to Example 11, and performed the X-ray-diffraction measurement and evaluation. The X-ray diffraction peak intensity ratio 1 and the evaluation results are shown in Table 3.

(Comparative Example 5)
Glass in the same manner as in Example 1 except that an amorphous alumina filler (average particle size: 1.5 μm, Showa Denko KK, trade name: AL-43-M) was used instead of the plate-like alumina filler. A ceramic substrate was produced. And it carried out similarly to Example 1, and performed the X-ray-diffraction measurement and evaluation. As a result, the peak intensity ratio 1 of X-ray diffraction was 0.04, and the bending strength was 250 MPa.

FIG. 9 is an X-ray diffraction chart of Comparative Example 5. As shown in FIG. 9, it was confirmed that when the amorphous alumina filler was used, the peak of the (006) crystal plane was smaller than the peak of the (110) crystal plane. From this result, it was confirmed that the peak intensity ratio 1 of each Example calculated by I ₀₀₆ / I ₁₀₄ is a value peculiar to the glass ceramic substrate containing a plate-like alumina filler.

  According to the present invention, it is possible to provide a glass ceramic substrate having a sufficiently excellent strength and a wiring substrate including such a glass ceramic substrate. Moreover, the manufacturing method of the glass-ceramics substrate which can manufacture the glass-ceramics substrate which has the fully outstanding intensity | strength stably can be provided.

  DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 1d ... Green sheet | seat for board | substrates, 2 ... Via conductor pattern, 3 ... Internal conductor pattern, 4 ... Surface conductor pattern, 5 ... Green sheet for shrinkage | contraction suppression, 10 ... Wiring board, 11a, 11b, 11c, DESCRIPTION OF SYMBOLS 11d ... Glass ceramic substrate, 12 ... Via conductor (conductor), 13 ... Internal conductor (conductor), 14 ... Surface conductor (conductor), 20 ... Plate-like alumina filler, 22 ... Glass.

Claims (6)

A slurry containing glass powder and a plate-like alumina filler is applied onto a substrate to form a film, and a film forming process for producing a green sheet is provided, and thermal contraction is smaller than that of the green sheet so as to sandwich the green sheet. A glass ceramic substrate obtained by a firing step of firing a laminate having a green sheet,
The green sheet is
Containing glass and a plate-like alumina filler dispersed in the glass,
The plate-like alumina filler has an aspect ratio of 25 or more and 70 or less,
A glass ceramic substrate having an intensity ratio of an X-ray diffraction peak of the (006) crystal plane to an X-ray diffraction peak of the (104) crystal plane of the plate-like alumina filler is 1.0 or more.   The glass ceramic substrate according to claim 1, wherein the alumina filler has an average plate diameter of 2 to 8 μm. The glass ceramic substrate according to claim 1, wherein the surface roughness Ra is 0.3 μm or less.   The wiring board which has a glass-ceramics board | substrate as described in any one of Claims 1-3, and a conductor on this glass-ceramics board | substrate. A film forming step of applying a slurry containing glass powder and a plate-like alumina filler having an aspect ratio of 20 or more on a substrate to form a green sheet,
The green sheet is fired to obtain a glass ceramic substrate in which the intensity ratio of the X-ray diffraction peak of the (006) crystal plane to the X-ray diffraction peak of the (104) crystal plane of the plate-like alumina filler is 1.0 or more. And a firing step. A method for producing a glass ceramic substrate.   The method for producing a glass ceramic substrate according to claim 5, wherein the glass powder has an average particle size of 2 μm or less.

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