JPH0782011A - Ceramic substrate and manufacturing method thereof - Google Patents

Abstract

(57) [Summary] [Structure] A ceramic substrate made of glass and crystals and containing a metal element, wherein the metal element is Cr,
A ceramics substrate which is one or more elements selected from Ti, Cu, Mn, Co and Fe, and the ceramics substrate is colored gray or black by containing these metal elements. [Effect] It is possible to provide a ceramic substrate that is sufficiently densified, has excellent properties such as moisture resistance and water resistance, and that can prevent the transmission of ultraviolet rays. Further, when the alignment target mark is formed on the ceramic substrate, the contrast with the ceramic substrate can be made clear. Further, since the ceramic substrate has a low softening point, it is possible to manufacture a substrate having the above-mentioned characteristics even if it is fired in an oxidizing atmosphere at 1000 ° C. or less.
Cu or the like can be used as the circuit wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic substrate and a method for manufacturing the same, and more particularly to a ceramic substrate often used as a multilayer wiring board for mounting electronic parts and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, ceramics have been increasingly used as a substrate material in multilayer wiring boards on which highly integrated LSIs and various electronic components are mounted, because of the demands for downsizing and reliability. Alumina is a representative example of these ceramics. Since this alumina has advantages such as high strength and excellent heat resistance, it occupies a large proportion in the ceramics for the substrate material,
On the other hand, since the relative permittivity is large, it causes a delay of the transmission signal, and the coefficient of thermal expansion is much larger than that of silicon, so that there is a problem that reliability cannot be secured when mounting components. Furthermore, alumina has a firing temperature of 15
Since it is as high as 00 ° C. or higher, it is necessary to use W or Mo having a high melting point and a large electric resistivity for the wiring in the inner layer, and therefore, there is a problem that the electric resistance becomes large when the wiring is miniaturized. There is.

In order to solve such a problem, therefore, the relative permittivity is made small, the coefficient of thermal expansion is made close to that of silicon, and a metal material having a low melting point such as Cu, Ag or Ag-Pd is used as the inner layer conductor. Research and development of low-temperature fired ceramics substrate materials that can be fired are underway.

Generally, a low temperature fired ceramics substrate is manufactured by mixing a glass material and a crystal material called an aggregate and firing the mixture. However, the number of combinations of glass materials and crystal materials is extremely large, and when they are combined, a synergistic effect is exerted during firing, and the characteristics of the resulting ceramic substrate (dielectric constant, thermal expansion coefficient, firing temperature, segregation strength) Etc.) changes. Therefore, it has been difficult to find the best combination and to manufacture a ceramic substrate having a stable composition and structure capable of always exhibiting certain characteristics.

Against this background, the strength is high, the speed of signal transmission is high, and the size of the mounted element is large without impairing the excellent characteristics that the relative permittivity is low and the coefficient of thermal expansion is close to that of silicon. As a low temperature fired ceramics substrate that can be applied to the above, cordierite (2MgO.2Al ₂ O _{3 as} disclosed in JP-A-2-225338 is disclosed.
The attention has been paid to 5SiO ₂ ) -based crystallized glass.

By the way, such a crystallized glass usually constitutes a sintered body in a state where glass and a crystalline aggregate are compounded, so that the sintered body itself is white and translucent. Has translucency. The characteristic of being white and translucent is also found in other packaging materials such as alumina, aluminum nitride, and mullite.

When the packaging material made of the above-mentioned material is irradiated with ultraviolet rays, a part of the ultraviolet rays may pass therethrough, which may adversely affect the life of the IC memory.

Japanese Unexamined Patent Publication (Kokai) No. 63-242971 discloses an aluminum nitride sintered body which contains alkaline earth metal tungsten and rare earth oxide and exhibits a black color in order to prevent transmission of this ultraviolet ray. .

On the other hand, the positioning when connecting the semiconductor integrated circuit element and the package external lead terminal with the semi-automatic wire bonder is performed by detecting the alignment target mark formed on the package with a sensor.
However, when the package is white, the contrast between the gold alignment target mark and the white package is weak, and an error may occur in alignment.

Japanese Unexamined Patent Publication No. 63-291860 discloses a mullite crystal phase and an alkaline earth metal glass phase which contain molybdenum in order to clarify the contrast between the alignment target mark and the package. A black mullite sintered body is disclosed.

[0011]

However, the above-mentioned JP-A-63-242971 and JP-A-63-29 are mentioned above.
In the sintered body disclosed in Japanese Patent No. 1860, a raw material compact to which metallic tungsten, metallic molybdenum, oxides thereof or alkali metal oxides thereof are added is fired in a reducing atmosphere to blacken the sintered body. When a molded body containing the metal or the like is fired in an oxidizing atmosphere that is normally fired, tungsten and molybdenum in the sintered body become oxides, and the obtained sintered body does not turn black. There was a problem.

The present invention has been made in view of the above problems, and it is sufficiently densified by firing at a temperature of 1000 ° C. or less in an oxidizing atmosphere, and various substrates such as moisture resistance and water resistance are provided. It is an object of the present invention to provide a gray or black-colored ceramic substrate which has characteristics satisfying the above requirement and can prevent the transmission of ultraviolet rays, and a method for manufacturing the same.

[0013]

In order to achieve the above object, a ceramic substrate according to the present invention is a ceramic substrate made of glass and crystals and containing a metal element, wherein the metal element is Cr or Ti. One or more elements selected from Cu, Mn, Co and Fe, and the ceramic substrate is colored gray or black by containing these metal elements. .

The method for producing a ceramic substrate according to the present invention is a method for producing a ceramic substrate in which glass powder, crystal grains and a metal compound are mixed and fired in a temperature range of 850 ° C. or higher and lower than 1000 ° C. The metal compound is composed of one or more compounds selected from Cr, Ti, Cu, Mn, Co and Fe or a mixture of these compounds, and the metal compound colors the ceramic substrate gray or black. It is characterized by that.

[0015]

According to the ceramic substrate having the above-mentioned structure, the ceramic substrate is made of glass and crystals and contains a metal element, and the metal element is Cr, Ti,
It is one or more elements selected from Cu, Mn, Co and Fe, and the ceramic substrate is colored gray or black by containing these metal elements, and is sufficiently densified. The ceramic substrate is excellent in various properties required for the ceramic substrate, such as moisture resistance and water resistance, and can prevent the transmission of ultraviolet rays. Further, when the alignment target mark is formed on the ceramic substrate, the contrast with the ceramic substrate becomes clear. Further, since the ceramics substrate has a low softening point, a ceramics substrate having the above-mentioned characteristics can be obtained even if the ceramics substrate is fired in an oxidizing atmosphere at 1000 ° C. or less, and Ag or Cu can be used for circuit wiring. Becomes

According to the method for producing a ceramic substrate having the above-mentioned structure, the glass substrate, the crystal grains and the metal compound are mixed and fired in a temperature range of 850 ° C. or more and less than 1000 ° C. The metal compound is composed of one or more compounds selected from Cr, Ti, Cu, Mn, Co and Fe or a mixture of these compounds, and the ceramic substrate is colored gray or black by the metal compound. As a result, the glass ceramics has a reduced porosity and is sufficiently densified, is excellent in various properties required for the ceramics substrates such as moisture resistance and water resistance, and is capable of preventing the transmission of ultraviolet rays.

In the ceramic substrate, the composition of the glass is borosilicate glass, lead borosilicate glass, crystallized glass such as cordierite crystallized glass or anorthite crystallized glass, and glass having other compositions. A composition having a composition that softens between 800 ° C and 800 ° C is preferable. This is because when a wiring pattern containing a low-resistance conductor such as Ag, Cu, Ag-Pd, or Au is formed inside or on the surface of the raw material powder compact and the compact and the wiring are simultaneously fired, This is because it is necessary to set the firing temperature of the molded body to 1000 ° C. or lower, and for that purpose, the softening point of the glass is preferably within the above range.

Examples of the crystals formed in the ceramic substrate include cordierite, anorthite, alumina, mullite, quartz and cristobalite.

By forming these crystal phases in the ceramic substrate, the fold strength is increased, and the thermal expansion coefficient of the entire substrate can be controlled by the thermal expansion coefficient of each crystal phase.

The metal element in the ceramic substrate is added in the form of one kind or two or more kinds of metal compounds or a mixture of these compounds, a part of which is melted into the glass to form glass. Some of which are dispersed in the glass or crystals in the form of oxides.

Examples of the crystal grains (aggregates) include alumina, mullite, cordierite, anorthite,
Examples thereof include spinel and quartz.

The metal compounds mixed in the glass powder and the crystal grains are Cr, Ti, Cu, Mn, Co and Fe.
It is one or two or more compounds selected from or a mixture of these compounds. The type of the metal compound is not particularly limited, but examples thereof include metal oxides and halides. Of these compounds, oxides are preferred,
Specific examples thereof include, for example, TiO ₂ , CuO, MnO.
₂ , Mn ₂ O ₃ , Cr ₂ O ₃ , CoO, Fe ₂ O _{3 and the} like can be mentioned. The oxide may be a single compound, a mixture thereof, or a compound of these oxides. Further, the compound of the above metal oxide may be a mixture of two or more of these.

The purpose of coloring the ceramics substrate in gray or black is to reduce the ultraviolet transmittance by this coloring and to clarify the contrast between the alignment target mark formed on the ceramics substrate and the ceramics substrate. Therefore, black is preferable because it is difficult to transmit ultraviolet rays and the like and has a clear contrast with the alignment target mark.

In order to stabilize the black color of the ceramic substrate, it is preferable to use a compound of metal oxides among the above-mentioned metal compounds, for example, CoO—Fe ₂ O ₃ —Cr.
_{2 O 3 -Mn 2 O 3,} CuO-Fe 2 O 3 -Mn 2 O
_{3, CoO-Fe 2 O 3} -Mn 2 O 3, Fe 2 O 3 -M
n ₂ O ₃ is preferred.

[0025]

EXAMPLES AND COMPARATIVE EXAMPLES Examples and comparative examples of the ceramic substrate and the manufacturing method thereof according to the present invention will be described below.

First, as a glass powder, SiO ₂ : 75
_{wt%, B 2 O 3:} 20wt%, Al 2 O 3: 1.5w
t%, the balance Li ₂ O, K ₂ O, Na ₂ O, TiO ₂ ,
Borosilicate glass having a composition of Fe ₂ O _{3 and having} an average particle size of 0.1 to 10 μm, SiO ₂ : 63 wt
%, Na ₂ O: 7.6 wt%, K ₂ O: 6 wt%, Ca
O: 0.3 wt%, MgO: 0.2 wt%, PbO: 2
Lead borosilicate glass having a composition of 1 wt% and the balance of B ₂ O ₃ and Al ₂ O _{3 and having} an average particle size of 0.1 to 10 μm.
, CaO: 18 wt%, SiO ₂ : 54 wt%,
Al ₂ O ₃ : 18 wt%, B ₂ O ₃ : 10 wt% anorthite crystallized glass having an average particle size of 0.1 to 10 μm, or MgO: 15 wt
%, Al ₂ O ₃ : 15 wt%, SiO ₂ : 50 wt%,
B ₂ O ₃ : 19 wt%, K ₂ O: 1 wt% of cordierite crystallized glass having an average particle size of 0.1
The one having a thickness of 10 μm was used. As the crystal grains (aggregate), Al ₂ O ₃ having an average grain size of 0.1 to 10 μm was used.

The above-mentioned glass powder, crystal grains and metal compound are mixed in the proportions shown in Table 1, and then the mixture is mixed with polyacrylic resin as an organic binder, dioxyl adipate as a plasticizer and xylene and butanol as a solvent. Add an appropriate amount of each and knead to about 10,000
The slurry was cps.

Next, using this slurry, a sheet having a thickness of 0.2 mm was formed by a doctor blade method, and the sheet was formed at 80 ° C. to about 1 mm.
It was dried for 0 minutes. After that, this sheet is placed in the atmosphere at 10 ° C.
The temperature is raised at a rate of / min, and baked at about 900 ° C for 30 minutes,
The manufacture of the sintered body of the ceramic substrate was completed.

The types and ratios of raw materials are shown in Table 1-1 below.
The characteristics of the obtained ceramic substrate are shown in Table 1-2 below.
Shown in.

In Comparative Examples 1 to 7, metal compounds such as MoO ₃ , WO ₃ , Cr ₂ O ₃ , TiO ₂ , CoO and F were used.
Using e ₂ O ₃ and ZnO, the glass powder, crystal grains (aggregate) and metal compound shown in Table 1-1 below are shown in Table 1-1.
The mixture was mixed in the ratio shown in, and thereafter, a sintered body of a ceramic substrate was manufactured in the same manner as in the example. The characteristics of the obtained ceramic substrate are shown in Table 1-2.

[0031]

[Table 1-1]

[0032]

[Table 1-2]

As is clear from Table 1-2, the ceramic substrates according to the examples have a black color, and their characteristics also satisfy the various characteristics required for the substrates.

The ceramic substrate according to the example has a black color, but when the amount of the metal compound added is reduced, the ceramic substrate has a gray color.

In Comparative Examples 1 to 7, metal compounds such as MoO ₃ , WO ₃ , TiO ₂ , Cr ₂ O ₃ , CoO,
Fe ₂ O ₃ and ZnO are used, and although the sintered body is sufficiently densified, it does not show gray or black.

[0036]

As described in detail above, the ceramic substrate according to the present invention is a ceramic substrate made of glass and crystals and containing a metal element, wherein the metal element is Cr, Ti, Cu, Mn. One or two or more elements selected from Co, Fe, and Co., and the ceramic substrate is colored gray or black by containing these metal elements, and is sufficiently densified and has moisture resistance. The ceramic substrate has excellent properties such as water resistance and can prevent the transmission of ultraviolet rays. Further, when the alignment target mark is formed on the ceramic substrate, the contrast with the ceramic substrate can be made clear. Further, the ceramic substrate is
Since it has a low softening point, even if it is fired in an oxidizing atmosphere at 1000 ° C. or lower, it is possible to produce the one having the above characteristics, and Ag or Cu can be used as the circuit wiring.

Further, according to the method for manufacturing a ceramic substrate having the above-mentioned structure, a method for manufacturing a ceramic substrate in which glass powder, crystal grains and a metal compound are mixed and fired in a temperature range of 850 ° C. or higher and lower than 1000 ° C. The metal compound is composed of one or more compounds selected from Cr, Ti, Cu, Mn, Co and Fe or a mixture of these compounds, and the ceramic substrate is colored gray or black by the metal compound. Therefore, the porosity of the glass ceramics is reduced to sufficiently densify it, and the moisture resistance,
It is possible to manufacture a ceramic substrate which has excellent properties such as water resistance and is sufficiently colored.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H05K 1/03 B 7011-4E

Claims (2)

[Claims] 1. A ceramic substrate comprising glass and crystals and containing a metal element, wherein the metal element is C.
It is one or more elements selected from r, Ti, Cu, Mn, Co and Fe, and the ceramic substrate is colored gray or black by containing these metal elements. Characteristic ceramics substrate. 2. A method for producing a ceramic substrate, which comprises mixing glass powder, crystal grains and a metal compound and firing the mixture in a temperature range of 850 ° C. to less than 1000 ° C., wherein the metal compound is Cr, Ti, Cu, Mn. 2. The ceramic according to claim 1, comprising one or more compounds selected from the group consisting of Co, Fe and Co or Fe or a mixture of these compounds, and coloring the ceramic substrate gray or black with the metal compound. Substrate manufacturing method.