JP2003128431A - Lead-free glass and glass ceramic composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lead-free glass having low dielectric constant and low dielectric loss for production of electronic circuit boards by firing at 900 deg.C or less. SOLUTION: The lead-free glass comprises 35-53 mol% of SiO2 , 0-10 mol% of B2 O3 , 5-18 mol% of Al2 O3 , 5-40 mol% of MgO, 7-40 mol% of CaO, 0-20 mol% of SrO+BaO, 0-10 mol% of ZnO, and 0-5 mol% of TiO2 +ZrO2 , and has 0.13 or more mole ratio of Al2 O3 /(MgO+CaO).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-free glass and a glass-ceramic composition suitable for producing an electronic circuit board by firing.

[0002]

2. Description of the Related Art Conventionally, an alumina substrate manufactured by sintering alumina powder has been widely used as an electronic circuit substrate.

[0003]

In the above alumina substrate, since the sintering temperature of the alumina powder is as high as about 1600 ° C., tungsten (melting point: 3400 ° C.), molybdenum, and Only high melting point metals such as (melting point: 2620 ° C.) could be used. Therefore, there is a problem that a non-high melting point metal such as silver (melting point: 962 ° C.) having a low specific resistance but a melting point of 1600 ° C. or less cannot be used as a material for the electrode.

Recently, 900, which replaces the alumina powder
There is a demand for a material for an electronic circuit board, which can be baked at a temperature of not higher than ° C to produce an electronic circuit board. An object of the present invention is to provide a lead-free glass and a glass ceramic composition that solve the above problems.

[0005]

Means for Solving the Problems The present invention is essentially expressed as mol% based on the following oxides: SiO ₂ 35 to 53%, B ₂ O ₃ 0 to 10%, Al ₂ O ₃ 5 to 18%. %, MgO 5-40%, CaO 7-40%, SrO + BaO 0-20%, ZnO 0-10%, TiO ₂ + ZrO ₂ 0-5%, SiO ₂ + Al ₂ O ₃ is 59% or less, Al _Two
Provided is a lead-free glass having an O ₃ / (MgO + CaO) molar ratio of 0.13 or more.

A glass-ceramic composition consisting essentially of the lead-free glass powder and a ceramic filler, wherein the lead-free glass powder is expressed as a mass percentage of 4
A glass-ceramic composition containing 0% or more is provided.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The lead-free glass of the present invention (hereinafter referred to as the glass of the present invention) is usually powdered to give a glass powder. The glass powder is suitable for producing an electronic circuit board by mixing it with a filler or the like as necessary and firing it.
The glass powder of the present invention precipitates crystals when fired at 900 ° C.

The glass transition point T _G of the present invention is preferably 800 ° C. or lower. If it exceeds 800 ° C, it may be difficult to produce a fired body that can be used as an electronic circuit board by firing the glass powder of the present invention at 900 ° C or lower. The temperature is more preferably 750 ° C or lower, and particularly preferably 725 ° C or lower.

When the glass of the present invention is used for producing an electronic circuit substrate for forming a silicon chip, the powder of the glass of the present invention is fired at 900 ° C. to obtain a fired product at 50 to 350 ° C.
Average linear expansion coefficient α at 30 × 10 ⁻⁷ / ° C. to 80
It is preferably × 10 ⁻⁷ / ° C. 80 x ^10-7
If the temperature exceeds / ° C, it may be difficult to match the expansion coefficient with the silicon chip when the silicon chip is formed on the electronic circuit board. More preferably 78 × 10 ⁻⁷
/ ° C or lower. If it is less than 30 × 10 ⁻⁷ / ° C., it may be difficult to match the expansion coefficient with the silicon chip.

The dielectric constant ε at 1 MHz of the fired body obtained by firing the glass powder of the present invention at 900 ° C. is 8.
It is preferably 5 or less. If it exceeds 8.5, when the glass of the present invention is used for an electronic circuit board, power consumption may increase. It is more preferably 8.0 or less, and particularly preferably 7.7 or less.

The dielectric loss tan δ at 20 ° C. and 1 MHz of the fired body obtained by firing the glass powder of the present invention at 900 ° C. is preferably 0.0040 or less.
If it exceeds 0.0040, power consumption may increase when it is used for manufacturing an electronic circuit board. More preferably 0.0
It is 030 or less, and particularly preferably 0.0020 or less.

The crystallization peak temperature T _C of the glass of the present invention is preferably 990 ° C. or lower. 9 above 990 ° C
It may not crystallize when fired at 00 ° C., or even if it crystallizes, the rate of crystal precipitation is small, and the electrical insulation of the electronic circuit substrate on which the silver electrode is formed may be lowered, that is, the glass is Before sufficient crystallization, silver for electrode formation may diffuse into the glass and the electrical insulation of the electronic circuit board may deteriorate. T _C is more preferably 970
C. or lower, particularly preferably 960.degree. C. or lower. In addition, T
_C is a crystallization peak temperature determined by differential thermal analysis.

The glass of the present invention is preferably one in which anorthite precipitates when the powder is fired at 900 ° C. If the anorthite does not precipitate when fired at 900 ° C., the above α becomes large, which may make it difficult to use the glass of the present invention for producing an electronic circuit substrate for forming a silicon chip.

The glass of the present invention is preferably one in which diopside is deposited when the powder is fired at 900 ° C. If diopside does not precipitate when baked at 900 ° C., the tan δ may increase. In order to further reduce the tan δ, it is more preferable that the glass of the present invention has both diopside and enstatite precipitated when the powder is fired at 900 ° C.

When the glass of the present invention is used for producing an electronic circuit board for forming a silicon chip, it is preferable that both anorthite and diopside are deposited when the powder is fired at 900 ° C. It is particularly preferred that all of anorthite, diopside and enstatite are precipitated.

Next, the components of the glass of the present invention will be described with mol% simply referred to as%. SiO ₂ is a network former and a component that lowers ε, and is essential. Further, SiO ₂ is a constituent component of anorthite and diopside. If it is less than 35%, ε tends to be large, and anorthite or diopside tends not to precipitate. It is preferably at least 40%. 53%
Above that, T _C becomes high. It is preferably 50% or less, more preferably less than 45%.

B ₂ O ₃ is not essential, but may be contained up to 10% in order to reduce T _G. If it exceeds 10%, the chemical durability is lowered. It is preferably 8% or less, more preferably 4% or less.

Al ₂ O ₃ is a component that stabilizes the glass and improves the chemical durability, and is essential. It is also a component of anorthite. If it is less than 5%, the glass tends to be unstable, or the chemical durability of the glass tends to deteriorate, and anorthite is unlikely to precipitate. It is preferably 5.6% or more, more preferably 7% or more, particularly preferably 8% or more. If it exceeds 18%, the glass melting temperature becomes high, or T _G becomes high. Preferably 15% or less, more preferably 12% or less, particularly preferably 10%
It is the following.

The total content of SiO ₂ and Al ₂ O ₃ SiO ₂ + Al ₂ O ₃ is 59% or less. If it exceeds 59%, T _C tends to be high. It is preferably 56% or less.

MgO has the effect of lowering ε, lowering tan δ, stabilizing the glass, or lowering the glass melting temperature, and is essential. If it is less than 5%, the effect is small. It is preferably at least 15%, more preferably at least 20%. If it exceeds 40%, the glass becomes rather unstable. It is preferably 35% or less, more preferably 33% or less.

CaO is a component that lowers the glass melting temperature and is essential. It is also a component of anorthite. If it is less than 7%, the glass melting temperature becomes high, and
Anorthite becomes difficult to deposit. It is preferably at least 10%, more preferably at least 12%. If it exceeds 40%, devitrification tends to occur. It is preferably 30% or less, more preferably 25% or less, and particularly preferably 20% or less.

Al_TwoO_ThreeContent of MgO and Ca
Molar ratio of total O content Al_TwoO _Three/ (MgO + Ca
If O) is less than 0.13, it is difficult for anorthite to precipitate.
It Preferably 0.14 or more, more preferably 0.16
That is all. Al_TwoO_Three/ (MgO + CaO) is preferred
Or less than 0.23. If it exceeds 0.23, tan δ is large.
There is a risk of hearing. More preferably 0.21 or less
is there. Al_TwoO_Three/ (MgO + CaO) is 0.14 or more
And, SiO_TwoIs preferably less than 50%
Good

Neither SrO nor BaO is essential, but in order to lower the glass melting temperature, the total content of these two components, SrO + BaO, may be contained up to 20%. If it exceeds 20%, the glass tends to devitrify, or ε becomes large. It is preferably 10% or less.

ZnO is not essential, but may be contained up to 10% in order to lower the glass melting temperature. 10%
If it exceeds the above range, the chemical durability, especially the acid resistance is deteriorated. It is preferably 5% or less.

[0025] Although TiO ₂ and ZrO ₂ is not essential, but in order to lower the glass melting temperature, or to facilitate precipitation of crystals during firing total TiO ₂ and ZrO ₂ content of these two components You may contain in the range up to 5%. If it exceeds 5%, the glass becomes unstable or ε becomes large. It is preferably 3% or less, more preferably 2% or less.

The glass of the present invention consists essentially of the above components, but may contain other components within the range not impairing the object of the present invention. The total content of the "other components" is preferably 10% or less. If it exceeds 10%, the glass may be easily devitrified. It is more preferably 5% or less.

Examples of the above-mentioned "other components" are as follows. That is, Bi ₂ O ₃ , P ₂ O ₅ , F or the like may be contained in order to lower the glass melting temperature. Further, in order to color the glass, Fe ₂ O ₃ , MnO, C
_{uO, CoO,} may contain coloring components such as _{V 2 O 5, Cr 2 O} 3.

The glass of the present invention is a lead-free glass containing no PbO. Further, the glass of the present invention is Li
It is preferable not to contain an alkali metal oxide such as ₂ O, Na ₂ O or K ₂ O. When these components are contained, electric insulation may be lowered and tan δ may be increased.

Next, the components of the glass-ceramic composition of the present invention will be described below using the mass percentage notation. The glass powder of the present invention is essential. If it is less than 40%, it becomes difficult to sinter, and it becomes difficult to produce an electronic circuit board by firing at 900 ° C or lower. It is preferably 55% or more.

The ceramic filler is a component that lowers α of the fired body or increases the strength of the fired body and is essential. If it exceeds 60%, it becomes difficult to sinter. It is preferably 45% or less.

The ceramic filler has a melting point of 1000 ° C.
The above ceramic powder or softening point is 1000 ° C
The above glass powder is preferable. Also baked
If you want to lower adult α, α of ceramic filler
Is 90 × 10 ^-7It is preferably below / ° C.

The ceramic filler is α-quartz (transition temperature: 1450 ° C.), amorphous silica (T _S : 1500).
° C), alumina (melting point: 2050 ° C), magnesia (melting point: 2820 ° C), forsterite (melting point: 1890)
℃), cordierite (transition temperature: 1450 ° C), mullite (melting point: 1850 ° C), zircon (melting point: 1680)
C.) and zirconia (melting point: 2710.degree. C.), preferably one or more powders of an inorganic substance selected from the group consisting of: When it is desired to reduce α of the fired body, the ceramic filler is more preferably one or more powders of an inorganic material selected from the group consisting of amorphous silica, alumina, cordierite, mullite and zircon. Alumina is more preferred.

The glass-ceramic composition of the present invention consists essentially of the above components, but may contain other components within the range not impairing the object of the present invention. The total content of the "other components" is preferably 10% or less. It is more preferably 5% or less. Examples of the "other components" include heat resistant color pigments.

When the glass-ceramic composition of the present invention is used for producing an electronic circuit board, it is usually used as a green sheet. That is, the glass ceramic composition is mixed with the resin. Next, a solvent or the like is added to form a slurry, and the slurry is formed into a sheet on a film such as polyethylene terephthalate by a doctor blade method or the like. Finally, it is dried to remove the solvent and the like to obtain a green sheet. Examples of the resin include polyvinyl butyral and acrylic resin, and examples of the solvent include dibutyl phthalate, dioctyl phthalate and butylbenzyl phthalate. The green sheet is fired to form an electronic circuit board.

[0035]

[Examples] Raw materials were mixed and mixed so that the composition shown in mol% in the column of SiO _{2 to} ZnO in the table was mixed, and the mixed raw materials were put into a platinum crucible and melted at 1500 ° C. for 120 minutes. The molten glass was poured out. A part of the obtained glass was crushed with an alumina ball mill for 10 hours to obtain glass powder. The remaining glass was gradually cooled at a temperature near the glass transition point in a lump state. Incidentally, _"Al 2 _O 3 / RO" in the table shows the _{Al 2 O 3 / (MgO +} CaO).

For the glasses of Examples 1 to 6, T _G (unit:
° C.), _{T C} (unit: ° C.), sinterability, precipitated crystals, epsilon, ta
nδ and α (unit: 10 ⁻⁷ / ° C.) were measured or evaluated as follows. Examples 1 to 5 are examples and Example 6 is a comparative example. The sinterability was good for all glasses. Other results are shown in the table.

T _G , T _C : Heating rate 1 by differential thermal analysis
The measurement was performed at room temperature to 1000 ° C. at 0 ° C./min.
Alumina powder was used as a standard substance.

Sinterability: 2 g of glass powder was used for 12.7 m in diameter
A sample was formed by pressure molding into a columnar shape of m. The fired body obtained by holding this sample at 900 ° C. for 60 minutes was visually observed. The good sinterability means that the fired body is densely sintered and no cracks are observed.

Precipitated crystals: The calcined product obtained by calcining glass powder at 900 ° C. for 30 minutes was crushed and the precipitated crystals were identified by X-ray diffraction. In the table, A indicates anorthite, E indicates enstatite, D indicates diopside, and F indicates forsterite.

Ε, tan δ: 40 g of glass powder 60 m
It is put into a m x 60 mm mold and pressure molded,
It was baked at 0 ° C. for 60 minutes. 50 mm x the obtained fired body
After processing into 50 mm × 3 mm, the dielectric constant and dielectric loss at 20 ° C. and 1 MHz were measured using an LCR meter.

Α: A fired body obtained by firing glass powder at 900 ° C. for 30 minutes was processed into a columnar shape having a diameter of 2 mm and a length of 20 mm, which was used as a sample, and measured using a differential thermal expansion meter.

[0042]

[Table 1]

[0043]

According to the present invention, an electronic circuit board having low ε and tan δ and which can be used for forming silicon chips can be produced by firing at a temperature of 900 ° C. or lower. The silver electrode can be simultaneously formed on the electronic circuit board.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C03C 10/06 C03C 10/06 H01B 3/02 H01B 3/02 A 3/08 3/08 A H05K 1 / 03 610 H05K 1/03 610D F-term (reference) 4G062 AA10 AA15 BB01 CC10 DA05 DA06 DB03 DB04 DC01 DC02 DC03 DD01 DD02 DE01 DE02 DE03 DF01 EA01 EB01 EC01 ED03 ED04 EE03 EE04 EE05 EF01 EF02 EF03 EF04 EG01 EG02 EG03 EG04 FA01 FA10 FB01 FB02 FB03 FC01 FC02 FC03 FD01 FE01 FF01 FF02 FG01 FH01 FJ01 FK01 FL01 GA01 GA02 GA10 GB01 GC01 GD01 GE01 GE02 HH01 PP03 KK01 HH08 HH09 PP06 KK KK KK JJ01 KK QQ08 5G303 AA05 AB05 AB15 BA12 CA02 CA03 CB01 CB02 CB03 CB06 CB17 CB30 CB32 CB35 CB38 CB39

Claims (5)

[Claims] 1. In terms of mol% based on the following oxides, essentially, SiO ₂ 35 to 53%, B ₂ O ₃ 0 to 10%, Al ₂ O ₃ 5 to 18%, MgO 5 to 40%, CaO 7-40%, SrO + BaO 0-20%, ZnO 0-10%, TiO ₂ + ZrO ₂ 0-5%, SiO ₂ + Al ₂ O ₃ is 59% or less, Al ₂
Lead-free glass having a molar ratio of O ₃ / (MgO + CaO) of 0.13 or more. 2. SiO ₂ is 50 mol% or less and Al ₂ O
The lead-free glass according to claim 1, wherein the molar ratio of ₃ / (MgO + CaO) is 0.14 or more. 3. A SiO ₂ content of less than 45 mol%.
Or the lead-free glass according to 2. 4. The lead-free glass according to claim 1, 2 or 3, wherein anorthite and diopside are precipitated when powdered and fired at 900 ° C. 5. A glass-ceramic composition consisting essentially of the lead-free glass powder according to claim 1, 2, 3 or 4 and a ceramic filler, wherein the lead-free glass powder is 40% in terms of mass percentage. A glass-ceramic composition containing the above.