JP2000143332A - Glass ceramic burned at low temperature - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass ceramic enabling the integration of a low-resistance conductor by simultaneous burning and suitable as an insulation layer of a multilayer printed circuit board for mounting a high-frequency analog circuit by using glass powder having a specific composition and ceramic powder at a specific ratio and burning at a specific temperature. SOLUTION: The amounts of glass powder and ceramic powder are 50-100 wt.% and 0-50 wt.%, respectively. The composition of the glass powder is SiO2: 35-65 wt.%, B2O3: 5-35 wt.%, CaO: 2-20 wt.%, Al2O3: 5-25 wt.% (the CaO:Al2O3 ratio is 1:1-2.5), TiO2: 0.5-5 wt.%, ZrO2: 0.5-5 wt.%, ZnO: 0.5-5 wt.%, MgO: 0-5 wt.%, SrO: 0-5 wt.%, BaO: 0-5 wt.% and group 1A element oxide: 0-1 wt.% in terms of oxides and the burning temperature is 850-1,000 deg.C. Multilayer printing with a low-resistance material can be performed and a substrate having excellent high-frequency characteristics can be produced by the use of the ceramic.

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 inorganic composition which can be fired simultaneously with low-resistance conductors such as Au, Ag, and Cu. Has a dielectric constant and low dielectric loss,
The present invention relates to a low-temperature fired glass ceramic suitable as an insulating layer of a multilayer wiring board for microwaves and millimeter waves.

[0002]

2. Description of the Related Art A low-temperature fired glass-ceramic multilayer wiring board is capable of multi-layered wiring, high-density and small-sized by fine wiring, low-resistance conductors Au, Ag and Cu can be selected as wiring materials, and an insulating layer. It has been used as an effective means for improving the performance of electronic devices, because the signal propagation speed can be increased by lowering the dielectric constant. Furthermore, since high-frequency analog circuits can be electrically shielded by high-density arrangement of solid conductor planes and via holes, miniaturization and high performance can be achieved by integrating transceiver modules and DC and RF circuits. It has been developed into a communication device module or the like including a high frequency analog circuit in a microwave band region.

[0003]

In the field of high-frequency communication equipment such as mobile communication and satellite communication, applications of systems in the ultra-high frequency band such as microwaves and millimeter waves are expected in the future. In a module equipped with such an analog circuit in the ultra-high frequency band, it is essential to suppress signal transmission loss. Therefore, the dielectric loss of the insulating layer material and the use of the conductive material in the glass ceramic multilayer wiring board are required. Low resistance is required.

It is an object of the present invention to sinter at a temperature of 1000 ° C. or less, that is, to simultaneously sinter low-resistance conductors such as Au, Ag, and Cu, and to reduce the dielectric constant at frequencies in the microwave and millimeter wave regions. An object of the present invention is to provide a low-temperature fired glass ceramic suitable for an insulating layer of a multilayer wiring board for mounting a high-frequency analog circuit having a low dielectric loss and a high efficiency.

[0005]

Means for Solving the Problems The present inventors have repeatedly studied various glass compositions in order to solve the above-mentioned problems in the conventional low-temperature fired glass ceramics.
In _{2 -B 2 O 3 -CaO-Al} 2 O 3 based glass certain composition range, the glass softening point is low, with it can be fired 1000 ° C. or less in complex with various ceramics,
They were found to crystallize during the firing process and show low dielectric constant and low dielectric loss.

That is, the low-temperature fired glass ceramic of the present invention has a glass powder content of 50 to 100 wt.
%, Ceramic powder 0 to 50 wt%, and the glass powder is 35 to 65 wt% of SiO _{2 in} terms of oxide.
_{B 2 O 3 5~35wt%, CaO2~20wt} %, Al 2
O ₃ 5-25 wt%, and the ratio of CaO and _{Al 2 O 3 1: 1~1:} 2.5, TiO 2 0.5~5wt%, Zr
O ₂ 0.5-5 wt%, ZnO 0.5-5 wt%, Mg
O0-5wt%, SrO0-5wt%, BaO0-5w
It has a composition of 0% to 1% by weight of a Group 1A element oxide, and is densified at a firing temperature of 850 to 1000 ° C.

According to the low-temperature fired glass ceramics of the present invention, it is possible to form a multilayer wiring with low-resistance conductors and to obtain a multilayer wiring board excellent in high-frequency characteristics.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The low-temperature fired glass ceramic of the present invention has a glass powder content of 50 to 100 wt.
%, Ceramic powder 0 to 50 wt%, and the glass powder is 35 to 65 wt% of SiO _{2 in} terms of oxide.
_{B 2 O 3 5~35wt%, CaO2~20wt} %, Al 2
O ₃ 5-25 wt%, and the ratio of CaO and _{Al 2 O 3 1: 1~1:} 2.5, TiO 2 0.5~5wt%, Zr
O ₂ 0.5-5 wt%, ZnO 0.5-5 wt%, Mg
O0-5wt%, SrO0-5wt%, BaO0-5w
t%, and Na ₂ O, K ₂ O, L
i ₂ O has a composition of 0 to 1% by weight and alumina and CaAl ₂ Si as main crystals in the firing process.
O ₆ is deposited.

SiO _{2 is} 35 to 65 wt% in terms of oxide,
_{B 2 O 3 5~35wt%, CaO2~20wt} %, Al 2
O _{3 in} the range of _{5 to} 25 wt%, and CaO and Al ₂ O
The composition in which the ratio of ₃ is in the range of 1: 1 to 1: 2.5 precipitates a crystal phase of alumina and CaAl ₂ SiO ₆ by firing,
It exhibits characteristics of low dielectric constant and low dielectric loss. In particular, S
_{iO 2 35~65wt%, B 2 O} 3 5~30wt%, Ca
O2~17.5wt%, in a range of Al ₂ O ₃ 5~17.5wt%, is yet the ratio of CaO and Al ₂ O ₃ 1: 1~
Compositions in the 1: 2.5 range are preferred because they have relatively low glass softening points and exhibit low dielectric constants and low dielectric losses.
The glass softening point of the composition is very high and sintering at temperatures below 1000 ° C. is difficult.

[0010] Further, TiO2 is added to the composition._Two0.5-5 wt%,
ZrO_Two0.5-5 wt%, ZnO0.5-5 wt%
When added, it is possible to reduce the
The effect of reducing the softening point is obtained. Over 5 wt%
Addition is not preferred because it significantly impairs the dielectric properties.
Also, the addition of less than 0.5 wt% is almost expected to be effective.
I can't. Preferably TiO_Two1-3 wt%, ZrO_Two1-3
wt%, ZnO1-3wt% is low dielectric constant and low dielectric
The loss can be maintained and the glass softening point can be lowered.
Good. In addition, MgO0-5 wt%, SrO0-5 wt%
% And BaO 0-5 wt% are the same as the above-mentioned additives.
Is effective in lowering the glass softening point. 5
Since the addition of more than wt% significantly impairs the dielectric properties,
Not desirable. Preferably, MgO 0.5-3 wt%, Sr
Add 0.5 to 3 wt% of O, 0.5 to 3 wt% of BaO
But keeps low dielectric constant, low dielectric loss and glass softening point
Can be reduced. Further lower the glass softening point
If_TwoO, K_TwoO, Li _Two0 to 1 wt% of O added
Is effective, but Na_TwoO, K_TwoO and Li_TwoO addition amount
Addition of more than 1 wt% increases the dielectric loss
Therefore, it is not preferable.

That is, 35-65 wt% of SiO ₂ , B ₂
O _{3 5 to} 35 wt%, CaO _{2 to 20} wt%, Al ₂ O ₃
5 to 25 wt%, and CaO: Al ₂ O ₃ = 1: 1 to 1:
_{2.5, TiO 2 0.5~5wt%, ZrO} 2 0.5~5
wt%, ZnO0.5-5wt%, MgO0-5wt
%, SrO 0 to 5 wt%, BaO 0 to 5 wt%, Na ₂ O, K ₂ O, Li ₂ O 0 to ₁ wt.
Glass composition consisting%, preferably SiO ₂ 35 to 65
_{wt%, B 2 O 3 5~30wt} %, CaO2~17.5w
t%, Al ₂ O ₃ 5-17.5 wt%, and CaO: Al
₂ O ₃ = 1: 1 to 1: 2.5, TiO ₂ 1 to ₃ wt%, Z
_{rO 2 1~3wt%, ZnO1~3wt%,} MgO0.
5-3 wt%, SrO0.5-3 wt%, BaO0.5
A glass composition comprising from 3 to 3 wt% has a low glass softening point, and a glass ceramic comprising 50 to 100 wt% of the glass powder and 0 to 50 wt% of a ceramic powder is 10%.
It can be fired at a temperature of 00 ° C. or less. As a result, the glass ceramic is characterized in that multilayer wiring using low-resistance conductors such as Au, Ag, and Cu can be performed by simultaneous firing, and that the glass ceramic has a low dielectric constant and a low dielectric loss in microwave and millimeter wave frequency bands. Can be provided.

The ceramic powder may be any of alumina, silica, mullite, cordierite, forsterite and the like, but those having a low dielectric constant and a low dielectric loss include:
This is preferable so as not to deteriorate the dielectric characteristics. A composite of glass and ceramics is desirable because the strength can be improved. However, if the ratio of the ceramic powder exceeds 50 wt%, it is not desirable because a high firing temperature is required. Preferably, the ratio of the ceramic powder is 5 to 30 wt% from the viewpoints of dielectric properties, strength, and firing temperature.

[0013]

EXAMPLES The present invention will be described more specifically below, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 A glass having a composition as shown in the composition ratio of Table 1 was produced and wet-pulverized using alcohol as a dispersion medium. After sieving and granulating, the alcohol was filtered off and dried to obtain a glass powder having an average particle size of about 2 μm. Next, an alumina powder having an average particle diameter of 1 μm was weighed so as to be 5% by weight of alumina and 95% by weight of the above glass powder, and mixed with a ball mill for 3 hours using alcohol as a dispersion medium. The mixture was dried to obtain a homogeneous mixed powder A. Similarly, a glass powder having a composition shown in Table 1 was wet-pulverized, granulated, filtered and dried to obtain a glass powder having an average particle size of 2 μm. Next, alumina powder having an average particle diameter of 1 μm, alumina 10% by weight, and glass powder 9
0%, 30% alumina, and 70% glass powder were weighed, and mixed powder B,
And a mixed powder C was prepared. After adding an organic binder, a plasticizer, and a solvent serving as a dispersion medium to each of the mixed powders A, B, and C, the mixture is sufficiently kneaded with a ball mill to have a viscosity of 300.
A slurry of 0-10000 cps was prepared. As the organic vehicles such as a binder, a plasticizer, and a solvent, those commonly used are sufficient, and there is no particular limitation on the components thereof. Each of the obtained slurries was formed into a green sheet having a thickness of 50 μm to 200 μm by a slip casting film forming method. In addition, a green sheet laminate was obtained by hot pressing the produced green sheet. The three types of green sheet laminates obtained by the above steps are fired in air at a maximum temperature of 1000 ° C.
Fired bodies A, B and C were obtained. The fired bodies A, B, and C correspond to the mixed powders A, B, and C, respectively. The dielectric properties of each fired body were evaluated by processing each fired body into a cylindrical shape having a diameter of about 12 mm and a height of about 5 mm, and measuring a dielectric constant and a dielectric loss tangent by a cavity resonator method. 10 of fired bodies A, B, C
The dielectric constant in the GHz band is 7.2, 7.4, respectively.
7.5, the dielectric loss tangent is 0.0012 and 0.00, respectively.
15, 0.0018, which was confirmed to be low dielectric constant and low dielectric loss.

Example 2 Glasses having compositions shown in Table 1 were produced, and glass powders D and E each having an average particle diameter of about 2 μm were prepared in the same process as in Example 1. did. After adding an organic binder, a plasticizer, and a solvent serving as a dispersion medium to each of these glass powders D and E, the mixture is kneaded with a ball mill and has a viscosity of 3000 to 10000 c.
A ps slurry was made. Each of the obtained slurries was formed into a green sheet having a thickness of about 100 μm by a slip casting film forming method, and the produced green sheets were laminated and hot pressed to obtain a green sheet laminate D.
E. The green sheet laminate D made of glass having the composition shown in the composition ratio in Table 1 was exposed to air at a maximum temperature of 9
Firing was performed at 00 ° C. to obtain a fired body D. Further, a green sheet laminate E made of glass having a composition shown in the composition ratio of Table 1 was fired in air at a maximum temperature of 850 ° C. to obtain a fired body E. Each fired body is about 12mm in diameter and about 5mm in height
When the dielectric constant and the dielectric loss tangent were measured by the cavity resonator method, the dielectric constants of the fired bodies D and E in the 10 GHz band were 6.0 and 6.4, respectively.
It was 0.0011 and 0.0018, respectively, and it was confirmed that the material had a low dielectric constant and a low dielectric loss. Also,
The crystal phase was identified by X-ray diffraction. From the fired body D, in addition to the glass phase, alumina and CaAl ₂ Si
It was confirmed that O ₆ precipitated alumina from the fired body E in addition to the glass phase.

Example 3 A glass having a composition shown in the composition ratio in Table 1 was manufactured, and the same process as in Example 1 was performed.
A glass powder having an average particle size of about 2 μm was produced. Next, the glass powder was 80% by weight, and the average particle size was 1 μm.
m of cordierite powder was weighed to 20% by weight, and ethanol was used as a dispersion medium.
After mixing for a period of time, the ethanol was filtered off and dried to obtain a homogeneous mixed powder.
A 00 μm green sheet was produced. The resulting green sheets were laminated and hot pressed to form a green sheet laminate, which was fired at a maximum temperature of 850 ° C. in the atmosphere to produce a sintered body F. About 14mm in diameter, about 6mm in height
When the dielectric constant and the dielectric loss tangent in the 10 GHz band were measured by the cavity resonator method, they were 5.6 and 0.0009, respectively, and it was confirmed that the dielectric constant and the dielectric loss were low. .

Example 4 A glass having a composition shown in the composition ratio of Table 1 was produced, and the same process as in Example 1 was performed.
Glass powder having an average particle size of about 2 μm was obtained. Next, the glass powder was weighed so as to be 90% by weight, and the alumina powder having an average particle size of about 1 μm was weighed so as to be 10% by weight. After mixing with a ball mill for 3 hours using ethanol as a dispersion medium, the ethanol was separated by filtration. Dry to a homogeneous mixed powder. After adding an organic binder, a plasticizer, and a solvent serving as a dispersion medium to the obtained mixed powder, the mixture was sufficiently kneaded with a ball mill to obtain a slurry having a viscosity of about 5000 cps, and a green sheet having a thickness of about 100 μm was prepared by a slip casting film forming method. . After punching the produced green sheet into a predetermined shape, a via hole was formed at a predetermined position of each green sheet, and an Ag paste was embedded in the existing via hole. Further, a wiring pattern was formed by printing an Ag paste on each green sheet by a screen printing method. The green sheets thus produced are laminated,
The laminate was integrated by hot pressing to obtain a laminate. The laminate was fired in the air at a maximum temperature of 900 ° C. to obtain a multilayer wiring board.
The dielectric constant and the dielectric loss tangent of the insulating layer of the multilayer wiring board were measured using the cavity resonator method, and it was confirmed that the dielectric constant and dielectric loss tangent in the 10 GHz band were 7.2 and 0.0009, respectively. When the specific resistance of the conductor was measured, it was about 3
μΩ · cm, and the multilayer wiring board has an insulating layer with a low dielectric constant and a low dielectric loss in a high frequency band, and has a low resistance conductor as an inner layer, and is suitable for a high frequency analog circuit board. Was confirmed.

[0018]

[Table 1]

[0019]

As described above, according to the low-temperature fired glass ceramics of the present invention, firing can be performed at a temperature of 1000 ° C. or less, that is, interiorization by simultaneous firing of low-resistance conductors such as Au, Ag, and Cu is possible. It is possible to provide a multilayer wiring board for mounting a high-frequency analog circuit having an insulating layer having a low dielectric constant and a low dielectric loss at frequencies in the microwave and millimeter wave regions.

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Claims (5)

[Claims] 1. A glass powder of 50-100% by weight.
wt%, it consists of ceramic powder 0~50wt%, SiO ₂ 35~65wt the glass powder is in the terms of oxide
_{%, B 2 O 3 5~35wt%} , CaO2~20wt%, A
l ₂ O ₃ 5~25wt%, and the ratio of CaO and _{Al 2 O 3 1: 1~1:} 2.5, TiO 2 0.5~5wt%, Zr
O ₂ 0.5-5 wt%, ZnO 0.5-5 wt%, Mg
O0-5wt%, SrO0-5wt%, BaO0-5w
A low-temperature fired glass ceramic, which has a composition of 0% to 1% by weight of a Group 1A element oxide and a densification at a firing temperature of 850 to 1000 ° C. 2. Group 1A element oxides are Na ₂ O, K ₂ O,
And low-temperature firing glass-ceramic according to claim 1, characterized in that one or more selected from Li ₂ O. 3. The low-temperature fired glass ceramic according to claim 1, wherein alumina is precipitated during the firing process. 4. The low-temperature fired glass ceramic according to claim 1, wherein CaAl ₂ SiO ₆ precipitates during the firing process. 5. The ceramic powder according to claim 1, wherein the ceramic powder is at least one selected from alumina, silica, mullite, cordierite, and forsterite. The low-temperature fired glass ceramic described.