JPH09208298A - Porcelain composition fired at a low temperature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a porcelain compsn. stably having a low dielectric constant and a low dielectric tangent in a high-frequency region as a circuit substrate for high frequency, having satisfactory mechanical strength as a multilayered circuit substrate and capable of attaining a multilayered state with Au, Ag or Cu as a circuit conductor by simultaneous firing at a low temp. of 800-1,000 deg.C. SOLUTION: A powdery mixture contg. 50-99.9wt.% glass consisting of SiO2 , Al2 O3 , MgO, ZnO and B2 O3 , 0.01-49.9wt.% zinc oxide and 0.01-49.9wt.% amorphous silica is compacted and fired at 800-1,000 deg.C in a nonoxidizing atmosphere to obtain the objective porcelain compsn. contg. a gahnite crystal phase 1, an enstatite crystal phase 2, an SiO2 crystal phase 3, an Mg2 B2 O5 crystal phase 4 and a glass phase 5 or further contg. a willemite crystal phase and a ZnO crystal phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low temperature fired porcelain composition for a multi-layer circuit board, and more particularly, it is applied to a multi-layer composite circuit board on which semiconductor elements and various electronic parts are mounted. The present invention relates to a high-frequency low-temperature fired porcelain composition capable of wiring gold (Au), silver (Ag) or copper (Cu).

[0002]

2. Description of the Related Art In recent years, with the advent of advanced information technology, information transmission has become faster and higher in frequency, and semiconductor elements to be mounted have also become faster and more highly integrated, and higher packaging density is required. In various circuit boards made of alumina, which have been frequently used, the relative dielectric constant is 9 to 3 at 3 GHz.
Since it is quite large at 9.5, it is said that it is unsuitable for a recent high frequency circuit board or the like.

That is, in order to propagate signals at high speed, a lower dielectric constant is required as a substrate material, and further, in the process of connecting various electronic parts and input / output terminals to the multilayer circuit substrate, the substrate is required. Higher mechanical strength is also required in order to prevent the substrate itself from breaking or chipping from the stress applied to the substrate.

Therefore, as a substrate material satisfying the above requirements, for example, a glass sintered body made of a glass composition containing SiO ₂ , Al ₂ O ₃ and MgO as a main component has been proposed. Although the sintered body has a low dielectric constant, it still has a problem of low mechanical strength, and it does not completely satisfy the above-mentioned requirements. Therefore, various researches and developments have been made to solve the problems.

As a result, as a composition having a low dielectric constant and high strength, for example, a glass composition in which mullite and cordierite are precipitated as a main crystal phase by heat treatment has been proposed (Japanese Patent Laid-Open No. 05-298919). See the bulletin).

[0006]

However, the multilayer circuit board made of the glass composition proposed above has a dielectric constant and a dielectric loss tangent which are required especially as a circuit board for high frequencies.
In addition, there is a problem that not all properties such as mechanical strength are necessarily satisfied.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and its object is to have a sufficient mechanical strength as a multilayer circuit board and to have a low dielectric constant and a low dielectric loss tangent in a high frequency region and to be stable. It also has the characteristic of being 80
Au and Ag, which are simultaneously fired at a low temperature of 0 to 1000 ° C,
An object is to provide a low-temperature fired porcelain composition suitable for high frequencies, which enables multilayering using Cu as a wiring conductor.

[0008]

DISCLOSURE OF THE INVENTION As a result of earnest studies on the above-mentioned problems, the present inventor made use of the softening flow of glass to obtain 80
By firing at 0 to 1000 ° C., it is possible to use Au, Ag, and Cu as wiring conductors for multilayering and fine wiring, and to specify zinc (Zn) oxide and amorphous silica. Glass is combined, the amount of zinc oxide is made smaller than the amount of amorphous silica, and the crystal phases are the garnite crystal phase, the enstatite crystal phase, the SiO ₂ crystal phase, and the Mg ₂ B ₂ O ₅ crystal phase. A glass phase is precipitated, or the amount of zinc oxide in the above combination is equal to or more than the amount of amorphous silica, and the crystal phase is a garnite crystal phase, a SiO ₂ crystal phase, and a willemite crystal phase, By precipitating the enstatite crystal phase, the Mg ₂ B ₂ O ₅ crystal phase, the ZnO crystal phase, and the glass phase, it becomes possible to lower the relative dielectric constant and the dielectric loss tangent, and it is a spinel crystal phase. Ghana By precipitating the door crystalline phase was found that higher strength can be attained, leading to the present invention.

That is, the low temperature fired porcelain composition of the present invention comprises at least SiO ₂ , Al ₂ O ₃ , MgO, ZnO and B.
50 to 99.9% by weight of glass containing ₂ O ₃ , 0.01 to 49.9% by weight of Zn oxide, and 0.01 to 49.9% by weight of amorphous silica. A low temperature fired porcelain composition suitable for a multi-layer circuit board for high frequency containing,
A sintered body obtained by firing at a low temperature of 800 to 1000 ° C. by changing the ratio of the amount of Zn oxide and the amount of amorphous silica is a garnite crystal phase, an enstatite crystal phase, and a SiO ₂ crystal. Phase, a Mg ₂ B ₂ O ₅ crystal phase, and a glass phase, or a garnite crystal phase and S
It is characterized by containing an iO ₂ crystal phase, a willemite crystal phase, an enstatite crystal phase, a Mg ₂ B ₂ O ₅ crystal phase, a ZnO crystal phase and a glass phase.

[0010]

According to the low temperature fired porcelain composition of the present invention, by containing zinc oxide as a filler component, a garnite crystal phase or a willemite crystal phase exhibiting a low dielectric constant and a low dielectric loss tangent is precipitated, and the filler component is further added. By including amorphous silica as described above, similarly, by depositing an enstatite crystal phase exhibiting a low dielectric constant and a low dielectric loss tangent, a low dielectric constant and a dielectric loss tangent suitable for high frequencies can be obtained.

Further, SiO ₂ --Al ₂ O ₃ --MgO--Z
with nO-B ₂ O ₃ based glass by blending zinc oxide as a filler component, by precipitating the gahnite crystal phase is a spinel-type crystal phase from the glass component, resulting flexural strength of the sintered body Get higher

Furthermore, the low temperature fired porcelain composition of the present invention comprises 8
Since it can be fired at the same time as the internal wiring layer of Au, Ag or Cu at a low temperature of 00 to 1000 ° C., it is easy to achieve a fine wiring of a multilayer circuit board or a package for accommodating semiconductor elements equipped with these wiring conductors. it can.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The low temperature fired porcelain composition of the present invention will be described in detail below.

According to the low temperature fired porcelain composition of the present invention, at least SiO ₂ , Al ₂ O ₃ , MgO, ZnO and B are used.
_{If the} amount of glass containing ₂ O ₃ is less than 50% by weight, in other words, if the total amount of the amount of oxides of Zn as a filler component and the amount of amorphous silica is more than 50% by weight, then 800
At a firing temperature of up to 1000 ° C., the porcelain cannot be sufficiently densified, and conversely, when the glass amount is more than 99.9% by weight or the filler component is less than 0.1% by weight, the dielectric constant is 5%. Higher than 0.6 and dielectric loss tangent is 20 × 1
^Greater than 0-4.

Therefore, the content of the glass is 50 to 9
It is specified to be 9.9% by weight, and more preferably in the range of 60 to 95% by weight.

Next, a schematic diagram of the structure of the sintered body of the low temperature fired porcelain composition of the present invention is shown in FIGS.

As shown in FIG. 1, the low temperature fired porcelain composition of the present invention comprises a garnite crystal phase 1, an enstatite crystal phase 2, a SiO ₂ crystal phase 3, and a Mg ₂ B ₂ O ₅ crystal phase 4.
And a glass phase 5, and the garnite crystal phase 1 exists as a main crystal in the sintered body.

As described above, according to the present invention, a low dielectric constant and a low dielectric loss tangent can be obtained by allowing the sintered body to contain the garnite crystal phase and simultaneously the enstatite crystal phase and the SiO ₂ crystal phase. it can.

Further, by adjusting the firing temperature and precipitating the garnite crystal phase, which is a spinel type crystal phase, in the sintered body, the crystal phase exists in a form that reinforces the network of each crystal phase. It is possible to obtain a sintered body having high dynamic strength.

Further, by reacting B ₂ O ₃ in the glass to precipitate a Mg ₂ B ₂ O ₅ crystal phase, chemical resistance can be remarkably improved.

Further, as shown in FIG. 2, the low temperature fired porcelain composition of the present invention has a garnite crystal phase 1, a SiO ₂ crystal phase 3, a willemite crystal phase 6, an enstatite crystal phase 2 and Mg ₂ B _{2. 2} O ₅ crystalline phase 4, ZnO crystalline phase 7,
It is composed of a glass phase 5 and a garnite crystal phase 1
Exists as a main crystal in the sintered body.

As described above, the garnite crystal phase is allowed to exist in the sintered body, and at the same time, the SiO ₂ crystal phase, the willemite crystal phase, the enstatite crystal phase, the Mg ₂ B ₂ O ₅ crystal phase, and the ZnO crystal phase. It is possible to obtain a low dielectric constant and a low dielectric loss tangent also by allowing the presence of.

Further, similarly to the description of FIG. 1, precipitation of a garnite crystal phase to enhance mechanical strength, and Mg ₂ B
It is also possible to improve the chemical resistance by precipitating a ₂ O ₅ crystal phase.

In the system composed of the crystal phase shown in FIG. 2, the glass is almost crystallized and exists only at the triple point, so that the dielectric loss tangent is low and the mechanical strength is high. .

Next, a specific method of manufacturing a low-temperature fired ceramic composition of the present invention, as a starting material, SiO ₂ -Al
₂ O ₃ —MgO—ZnO—B ₂ O ₃ based glass 50 to 9
9.9% by weight, particularly preferably 60 to 95% by weight, 0.01 to 49.9% by weight of zinc oxide and 0.01 to 49.9% by weight of amorphous silica as filler components. ,
Particularly, the zinc oxide is mixed in an amount of 5 to 29% by weight, and the amorphous silica is mixed in an amount of 1 to 25% by weight.

The zinc oxide as the filler component can be added in various forms such as ZnO powder, carbonate capable of forming ZnO in the firing process, nitrate, acetate and the like.

It is important for the zinc oxide to precipitate a garnite crystal phase or a willemite crystal phase by a reaction with glass. From this viewpoint, the particle size of the powder is 1.5 μm or less, particularly 1 μm. It is desirable that the powder is a fine powder having a particle size of 0.0 μm or less.

On the other hand, when amorphous silica is used as the filler component, it is important to precipitate an enstatite crystal phase by reaction with glass, and the amorphous silica powder has a particle size of 1.5 μm or less. In particular, fine powder having a particle size of 1.0 μm or less is desirable.

Further, as a starting material, SiO ₂ --Al ₂
The O ₃ —MgO—ZnO—B ₂ O ₃ system glass is used because the spinel type crystal phase is precipitated by using this system glass, and this crystal phase exists in a form that reinforces the glass network, This is because a strong sintered body can be obtained.

Further, glass of such a system is used in an amount of 50 to 99.9.
The amount added in the range of wt% is that when the glass amount is less than 50 wt%, the densification temperature of the sintered body becomes higher than 1000 ° C. and the conductor of gold, silver or copper cannot be used, This is because the bending strength of the porcelain itself decreases when the amount is more than 99.9% by weight.

Therefore, SiO ₂ --Al ₂ O ₃ --MgO--
The addition amount of ZnO-B ₂ O ₃ based glass, more preferably 60-95 wt%, and most preferably 70 to 85 wt%.

As a more specific composition of the glass of such a system, SiO ₂ is 40 to 45% by weight and Al ₂ O ₃ is 25 to 45% by weight.
30 wt%, MgO 8-12 wt%, ZnO 6-9
Wt%, B ₂ O ₃ is desirably 8-11% by weight.

A binder is appropriately added to the mixed powder which is added and mixed in the above-described proportion, and then the powder is molded into a predetermined shape.
₂ , 800 to 100 in a non-oxidizing atmosphere such as Ar
Baking at a temperature of 0 ° C. for 0.1 to 5 hours. If the firing temperature at this time is lower than 800 ° C, the porcelain will not be sufficiently densified and
If the temperature exceeds 00 ° C, the conductor of gold, silver or copper cannot be used.

When a wiring board is produced using such a low temperature fired porcelain composition, for example, the mixed powder prepared as described above is subjected to a known tape forming method such as a doctor blade method or a rolling method. After molding a green sheet for forming an insulating layer, a powder of Au, Ag, or Cu, particularly C, is formed on the surface of the green sheet as a metallization for a wiring layer.
Using a metal paste containing u powder, a wiring pattern is formed on the surface of the sheet by means of screen printing, gravure printing, offset printing, or the like. In some cases, a through hole is formed in the sheet and the paste is placed in the through hole. Fill. Then, after laminating and pressing multiple sheets,
By firing under the conditions described above, the wiring layer and the insulating layer can be fired at the same time.

[0035]

EXAMPLES Hereinafter, the low-temperature fired porcelain composition of the present invention will be described in detail. First, SiO ₂ -Al ₂ O ₃ -Mg
As O-ZnO-B ₂ O ₃ based crystalline glass, crystalline glass A: SiO ₂ 44 wt% -Al ₂ O ₃ 29 wt% -MgO11 wt% -ZnO7 wt% -B ₂ O ₃ 9 wt% crystalline Glass B: Two kinds of glass of 50% by weight of SiO _2, 25% by weight of Al ₂ O _{3, 9} % by weight of MgO, 8% by weight of ZnO and 8% by weight of B ₂ O _3, and zinc oxide (ZnO having an average particle diameter of 1 μm or less). ) And amorphous silica (SiO ₂ ) were mixed according to the composition of Table 1.

Then, an organic binder, a plasticizer, and toluene were added to the mixture, and a green sheet having a thickness of 300 μm was prepared by the doctor blade method. After that, 5 sheets of this green sheet are laminated, and 100 at a temperature of 50 ° C.
A pressure of kg / cm ² was applied for thermocompression bonding.

The thus obtained laminate was debindered at a temperature of 700 ° C. in a nitrogen atmosphere containing water vapor and then fired in dry nitrogen under the conditions shown in Table 1 to sinter the low temperature fired porcelain composition. Got the body

[0038]

[Table 1]

Using the sintered body for evaluation, the dielectric constant, dielectric loss tangent and flexural strength were measured and evaluated by the following methods.

First, with respect to the dielectric constant and the dielectric loss tangent, a sample with a diameter of 10 mm and a thickness of 5 mm was cut out from the sintered body, and
It was measured by a cylindrical resonator method using a network analyzer and a synthesized sweeper at -20 GHz.

Specifically, the dielectric substrate of the sample is sandwiched between copper plate jigs having a diameter of 50 mm for measurement, and TE011 of the resonator is measured.
The dielectric constant and dielectric loss tangent were calculated from the resonance characteristics of the modes.

Next, the bending strength is 70 mm from the sintered body.
mm, thickness 3 mm, width 4 mm to prepare a measurement sample, JI
A three-point bending test was performed according to the specifications of S-C-2141.

Further, as a comparative example, a sintered body was prepared and evaluated in the same manner as above, except that crystalline silica and calcia (CaO) were used as the filler component instead of the zinc oxide and the amorphous silica.

Further, instead of the crystalline glass, crystalline glass C: SiO ₂ 55.2% by weight-Al ₂ O ₃ 12% by weight-B ₂ O ₃ 4.4% by weight-BaO 20% by weight-ZnO 6.7 wt% -Na ₂ O1.6 wt% -ZrO ₂ 0.1 wt% crystalline glass D: SiO ₂ 60.7 wt% -Al ₂ O ₃ 9.3 wt% -B ₂ O ₃ 5 wt% -SrO15 with .4 wt% -ZnO8.6 wt% -K ₂ O1 wt% of the two glass was evaluated in the same manner as described above the average particle size of various combinations of the respective filler 1.0 .mu.m.

[0045]

[Table 2]

As is clear from the results shown in the table, a garnite crystal phase, an enstatite crystal phase, and a Si
O ₂ crystal phase, Mg ₂ B ₂ O ₅ crystal phase and glass phase precipitated, or garnite crystal phase, SiO ₂ crystal phase, willemite crystal phase, enstatite crystal phase, Mg ₂ B ₂ The present invention in which the O ₅ crystal phase, the ZnO crystal phase, and the glass phase are precipitated has a dielectric constant of less than 5.6,
Dielectric loss tangent is 10 × 10 ^-4 or less, strength is 22 kg / mm ²
The above values are high, and it can be seen that the dielectric characteristics are particularly excellent.

On the other hand, in Sample Nos. 1, 14, 15 and 27 in which the amount of glass is less than 50% by weight, densification cannot be achieved unless the firing temperature is raised to 1200 ° C. or higher and 1400 ° C. Is also as high as 20 × 10 ⁻⁴ or more, and conversely, in Sample Nos. 10 and 23 in which the weight exceeds 99.9% by weight, the strength is low as 18 kg / mm ² or less and the dielectric loss tangent is also 20 × 1.
It is as high as ^0-4 .

When the amount of one of the fillers is less than 0.01% by weight, as in sample numbers 11 and 24,
Both of them have a low strength of 20 kg / mm ² or less.

On the other hand, as a comparative example, sample No. 32 using crystalline silica as the filler has a low dielectric constant,
The dielectric loss tangent is as high as 35 × 10 ^−4, and sample number 33 using calcia has a high dielectric constant and a high dielectric loss tangent, which does not satisfy the object of the present invention.

Further, in Sample Nos. 34 to 37 of Comparative Examples using the crystallized glasses C and D, it was not possible to sufficiently densify by firing in a low temperature range of 800 to 1000 ° C.,
It can be seen that in any case, a sintered body having a low dielectric constant, a low dielectric loss tangent and a high strength cannot be obtained.

[0051]

As described in detail above, since the low temperature fired porcelain composition of the present invention has a low dielectric constant and a small dielectric loss tangent, it can be optimized and miniaturized in microwave circuit elements for high frequency applications. Further, by strengthening the substrate material, it is possible to improve the bonding of leads to the input / output terminal portion and the reliability of the substrate during mounting, and since it is possible to fire at a low temperature of 800 to 1000 ° C., Au, Ag, Cu, etc. Can be formed by simultaneous firing, and can be applied as a multilayer wiring substrate for various high frequencies or a substrate for a package for housing a semiconductor element.

[Brief description of drawings]

FIG. 1 is a schematic view of the structure of the low-temperature fired porcelain composition of the present invention.

FIG. 2 is a schematic view of another structure of the low temperature fired porcelain composition of the present invention.

[Explanation of symbols]

1 Garnite Crystalline Phase 2 Enstatite Crystalline Phase 3 SiO ₂ Crystalline Phase 4 Mg ₂ B ₂ O ₅ Crystalline Phase 5 Glass Phase 6 Willemite Crystalline Phase 7 ZnO Crystalline Phase

Claims (2)

[Claims] 1. At least silica (SiO ₂ ), alumina (Al ₂ O ₃ ), magnesia (MgO), zinc oxide (Z
nO) and a glass containing boron oxide (B ₂ O ₃ ) of 50 to
99.9% by weight and 0.01 to 0.01% of zinc (Zn) oxide.
49.9% by weight, and amorphous silica (SiO ₂ ) of 0.
01 to 49.9 comprises a proportion by weight%, and the molded article the amount of the zinc oxide (ZnO) is composed of amorphous silica mixed powder is smaller than (SiO ₂₎ content, nitrogen (N _2), 800 to 1000 in a non-oxidizing atmosphere such as argon (Ar)
The sintered body obtained by firing at a temperature of ℃, Gunite crystal phase, Enstatite crystal phase, SiO ₂ crystal phase, M
A low temperature fired porcelain composition comprising a g ₂ B ₂ O ₅ crystal phase and a glass phase. 2. At least silica (SiO ₂ ), alumina (Al ₂ O ₃ ), magnesia (MgO), zinc oxide (Z
nO) and a glass containing boron oxide (B ₂ O ₃ ) of 50 to
99.9% by weight and 0.01 to 0.01% of zinc (Zn) oxide.
49.9% by weight, and amorphous silica (SiO ₂ ) of 0.
A molded body made of a mixed powder containing 01 to 49.9% by weight and containing zinc oxide (ZnO) in an amount equal to or more than the amount of amorphous silica (SiO ₂ ) is mixed with nitrogen (N ₂ ),
800 to 10 in a non-oxidizing atmosphere such as argon (Ar)
The sintered body obtained by firing at a temperature of 00 ° C. contains a garnite crystal phase, a SiO ₂ crystal phase, a willemite crystal phase,
Enstatite crystal phase, Mg ₂ B ₂ O ₅ crystal phase, Z
A low-temperature fired porcelain composition comprising an nO crystal phase and a glass phase.