JP2002037644A - Glass for sealing and sealing material which uses it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a consistent glass for sealing which is P2O5 base and yet highly water resistant. SOLUTION: The glass is P2O5 base containing 0.01-20 mol% of Ga2O3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing glass and a sealing material, and more particularly to a sealing material suitable for hermetically sealing a package having a heat-sensitive element such as a semiconductor integrated circuit and a quartz oscillator. It is.

[0002]

2. Description of the Related Art Conventionally, a sealing material using low melting point sealing glass has been used for hermetic sealing of a highly reliable package on which elements such as a semiconductor integrated circuit and a quartz oscillator are mounted.

As a sealing material of this type, a material obtained by adding a low-expansion refractory filler powder such as lead titanate and willemite to a PbO-based glass powder is known. is, PbO-V ₂ O ₅ -Bi
A sealing material using ₂ O ₃ -based glass is disclosed, and JP-A-63-315536 discloses PbO-Tl ₂ O-B ₂ O.
Sealing materials using ₃ based glass is disclosed.

[0004]

Problems to be Solved by the Invention
The sealing materials disclosed in Japanese Patent No. 502583 and JP-A-63-315536 contain a large amount of PbO and Tl ₂ O, but lead is a harmful substance, and thallium is toxic. Is not preferred.

The sealing material disclosed in JP-A-63-502583 can be sealed at about 330 ° C. However, in order to seal at such a low temperature, a metal clip or the like is used at the time of sealing. And a considerable load must be applied.

Further, the sealing material disclosed in JP-A-63-315536 can be sealed at about 330 ° C.
Depending on the type of package, even if sealed at 330 ° C,
Since the characteristics of the element and the like may be deteriorated, a material that can be sealed at a lower temperature is required.

In recent years, from such circumstances, as a sealing material which is low in harmful substances and toxic substances and can be sealed at a low temperature, P
Attempts have been made to develop a sealing material obtained by mixing a ₂ O ₅ -based sealing glass powder with a refractory filler. This P ₂ O ₅ -based sealing glass has the advantages of a low transition point and good fluidity at low temperatures, but has the problem that the water resistance is reduced and the glass tends to be unstable. If the water resistance of the sealing material is low, it is difficult to obtain a sealing material having long-term reliability that can withstand long-term use in an environment in which a temperature difference occurs at high humidity, and long-term reliability is required. It cannot be used as a sealing material for electronic components mounted on information-related equipment. In addition, when the glass becomes unstable, it becomes difficult to form the glass,
The glass tends to separate phases and cannot be used as a product.

A first object of the present invention is to provide a stable sealing glass which is excellent in water resistance while being a P ₂ O ₅ sealing glass.

A second object of the present invention is to provide a sealing material that can seal a package well at a low temperature of 330 ° C. or less without applying a load.

[0010]

The sealing glass of the present invention is a P ₂ O ₅ -based glass, wherein Ga ₂ O ₃ is contained in an amount of 0.01 to ₂ %.
Characterized by containing 0 mol%, preferably, in _{mole%, AgI + Ag 2 O 15~85} %, P 2 O 5 1
_{0~55%, Ga 2 O 3 0.01~20} %, TeO 2
0~60%, 0~50% ZnO, Nb 2 O 5 0~30
%, WO ₃ 0-30%.

The sealing material of the present invention is a P ₂ O ₅ -based glass, in which 45 to 90% by volume of glass powder for sealing containing 0.01 to 20 mol% of Ga ₂ O ₃ is used. It is characterized by comprising 10 to 55% by volume of the conductive filler powder.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION According to the findings of the present inventors, P ₂
In an O ₅ -based sealing glass, in a composition region in which sealing can be performed at a low temperature, water resistance is likely to be reduced or unstable, but the glass of this system contains a predetermined amount of Ga ₂ O ₃ . In this case, even in a composition region where low-temperature sealing is possible, the water resistance is improved, and the glass is stable and has good fluidity.
It flows well below.

A preferred composition range of the sealing glass of the present invention, in _{mol%, AgI + Ag 2 O15~85%} , P 2 O 5
_{10~55%, Ga 2 O 3 0.01~20} %, TeO
_{2 0~60%, 0~50% ZnO,} Nb 2 O 3 0~3
0%, is a WO ₃ 0 to 30% reason for limiting such compositional range is as follows.

AgI and Ag ₂ O are the main components of the glass to be sealed and are hardly soluble in water, so that they have the effect of increasing the water resistance of the glass.
The viscosity of the glass becomes high, so that low-temperature sealing becomes difficult and the water resistance tends to decrease. On the other hand, if it is more than 85%, vitrification tends to be difficult. A more preferred amount of Ag1 + Ag ₂ O is 35-80%.

[0015] P ₂ O ₅ is also a main component of the glass for sealing, but if it is less than 10%, vitrification becomes difficult, and
%, The viscosity of the glass tends to increase. P ₂ O ₅
Is more preferably 15 to 40%.

Ga ₂ O ₃ has remarkable effects on increasing the stability of glass, improving water resistance, and decreasing the coefficient of thermal expansion.
If the amount is less than 0.01%, the above-described effects are poor,
If it is more than 20%, the viscosity of the glass tends to increase. G
A more preferred amount of a ₂ O ₃ is 0.1 to 10%.

TeO ₂ also has the effect of increasing the stability of the glass, improving the water resistance, and lowering the coefficient of thermal expansion. However, if it exceeds 60%, the viscosity of the glass tends to increase. A more preferred amount of TeO ₂ is from 0 to 20%.

ZnO is also effective in increasing the stability of glass, improving water resistance, and lowering the coefficient of thermal expansion.
If it is more than 50%, the viscosity of the glass tends to increase. Z
A more preferable range of nO is 0 to 30%.

Nb ₂ O ₅ is also effective in increasing the stability of the glass, improving the water resistance, and lowering the coefficient of thermal expansion. However, if it exceeds 30%, the viscosity of the glass increases. A more preferred amount of nb ₂ O ₃ is 0 to 15.

WO _{3 is} also effective in increasing the stability of glass, improving water resistance, and lowering the coefficient of thermal expansion. However, if it exceeds 30%, the viscosity of the glass increases. A more preferred amount of WO ₃ is 0-15%.

In the present invention, 5 mol% or less of Li ₂ O, SiO ₂ , B ₂ O ₃ , Pb
O, Al ₂ O ₃ , MnO ₂ , In ₂ O ₃ , MoO ₃ , Bi
₂ O ₃ , CuO, GeO ₂ , Li, Si, B, Pb, A
1, Mn, In, Mo, Cu, Co, Ge, W, Zn,
Te, Ga, P, Ag halides (excluding AgI)
And Li, Si, B, Pb, Al, Mn, In, Mo,
It is possible to contain sulfides of Cu, Co, Ge, W, Zn, Te, Ga, P, and Ag. However, as described above, since the lead component is a harmful substance, it is desirable not to include it.

Incidentally, the halide means a fluoride, chloride, bromide or iodide. When the metal element is the same, the effect of lowering the viscosity of the glass is larger than that of using an oxide. .

By the way, the above glass for sealing is 30 to 1
The coefficient of thermal expansion in the temperature range of 50 ° C. is 130 to 250
It is as high as × 10 ^-7 / ° C, and its mechanical strength is insufficient as a package sealing material. Therefore, the glass powder 45 to sealing is adapted to the package to be sealed.
It is preferable to mix 10 to 55% by volume of the refractory filler powder with respect to 90% by volume to adjust a high coefficient of thermal expansion or improve mechanical strength.

NbZr (PO ₄ ) ₃ and Sr _0.5 Zr ₂ P ₃ O are mainly used as refractory fillers for lowering the coefficient of thermal expansion.
NaZr ₂ (PO ₄ ) ₃ type solid solution such as ₁₂ , lead titanate and its solid solution, willemite, cordierite, zircon, tin oxide, β-eucryptite, zirconium phosphate, niobium pentoxide, quartz glass, mullite, titanate Aluminum or the like can be used, and cubic zirconia or the like can be used as the refractory filler that does not lower the coefficient of thermal expansion. Further, as the refractory filler mainly for improving the mechanical strength, alumina, zirconia, titania, zinc stannate, magnesia, quartz, spinel, garnite and the like can be used. These refractory fillers may be used alone or in combination of two or more.

When a refractory filler powder is used in the present invention, 45 to 90% by volume of glass powder for sealing is used.
It is preferable to mix the refractory filler powder at a ratio of 10 to 55% by volume. That is, when the glass powder for sealing is more than 90% by volume (when the refractory filler powder is less than 10% by volume), the effect of adjusting the thermal expansion coefficient or improving the mechanical strength is poor. When the glass powder is less than 45% by volume (the refractory filler powder
If the content is more than 5% by volume), the fluidity of the sealing material is significantly reduced.

In the present invention, in terms of mol%, Ag ₂
O 20-60%, P ₂ O ₅ 20-50%, Ga ₂ O _{3
0.01~20%, TeO 2 + ZnO +} Nb 2 O 5 + WO 3
Glass for sealing having a composition of 0 to 70%, mol%
And Ag ₂ O 10-65%, AgI 5-50%, P _{2
O 5 10~40%, Ga 2 O} 3 0.01~20%, T
It is more preferable to use sealing glass having a composition of eO ₂ + ZnO + Nb ₂ O ₅ + WO _{3 from} 0 to 70%, since a glass having particularly excellent water resistance and stability and low expansion can be obtained.

The reasons for limiting the composition range of the sealing glass are as follows.

When the content of Ag ₂ O is less than 20%, the water resistance of the glass decreases, and when the content is more than 60%, the stability becomes slightly poor. A more preferred amount of Ag ₂ O is 20
５０50%.

When the content of P ₂ O ₅ is less than 20%, the stability becomes slightly poor. When the content is more than 50%, the viscosity of the glass becomes slightly high. A more preferred amount of P ₂ O ₅ is 20-40%
It is.

If the content of Ga ₂ O ₃ is less than 0.01%, the effect of stabilizing the glass becomes small, and if it is more than 20%, the viscosity of the glass becomes high. A more preferred amount of Ga ₂ O ₃ is 0.1 to 10%.

TeO ₂ , ZnO, Nb ₂ O ₅ , and WO ₃ are effective for increasing the stability of glass, improving water resistance, and reducing the coefficient of thermal expansion. Therefore, it is necessary to suppress the total amount to 70% or less, preferably 50% or less.

The reason for limiting the composition range of the glass for sealing is as follows.

If the content of Ag ₂ O is less than 10%, the water resistance of the glass is lowered, and if it is more than 65%, the stability becomes slightly poor. A more preferred amount of Ag ₂ O is 15 to 55%.

If the content of AgI is less than 5%, the water resistance of the glass is lowered, and if it is more than 50%, the stability is somewhat poor. A more preferred amount of Ag1 is 10-45%.

When the content of P ₂ O ₅ is less than 10%, the effect of stabilizing the glass is reduced, and when the content is more than 40%, the viscosity of the glass is slightly increased. A more preferred amount of P ₂ O ₅ is
15 to 40%.

If the content of Ga ₂ O ₃ is less than 0.01%, the effect of stabilizing the glass is reduced. If the content is more than 20%, the viscosity of the glass is slightly increased. More preferred amounts of Ga ₂ O ₃ is 0.1 to 10%.

TeO ₂ , ZnO, Nb ₂ O ₅ , and WO ₃ are effective in increasing the stability of glass, improving water resistance, and reducing the coefficient of thermal expansion. Therefore, it is necessary to suppress the total amount to 70% or less, preferably 50% or less.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments.

Tables 1 to 4 show the sealing glass of the present invention (sample Nos. 1 to 24) and the sealing glass of the comparative example (sample No. 1).
25 to 27).

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

[Table 4]

Each sample in the above table was prepared as follows.

First, each raw material of silver iodide, silver oxide, orthophosphoric acid, gallium oxide, tellurium dioxide, zinc oxide, niobium pentoxide, and tungsten oxide was prepared so as to have the glass composition shown in the table, and put into a platinum crucible. Then, the mixture was melted at 700 ° C. for 1 to 2 hours, formed into a thin plate, pulverized, and passed through a stainless steel sieve of 250 mesh to obtain a powder having an average particle size of 7 μm.

As is clear from the table, the embodiment N
o. It can be understood that each of the samples Nos. 1 to 24 has a low glass transition point, so that the viscosity of the glass is low. Further, all of these samples were “good” or “good” in water resistance, stability and fluidity. Each of the samples 25 to 27 was “poor”. By the way, in the comparative example No. 1; Samples Nos. 25 to 27 are Nos. In Examples. 1
The Ga ₂ O ₃ of each sample to 3, respectively Nb ₂ O _5, Zn
O and Ag ₂ O were substituted. From these comparisons, it can be understood that when Ga ₂ O ₃ is contained in the P ₂ O ₅ -based glass, the water resistance of the glass is improved and the glass is stabilized.

The glass transition point and the coefficient of thermal expansion in the table are as follows:
After the glass was formed into a size of 40 × 10 mmφ, it was measured by a quartz push-bar type thermal dilatometer.

The water resistance was determined by placing a glass cullet formed in the form of droplets on a plate made of alumina at 85 ° C., a humidity of 85% and a humidity of 85%.
A test in which the treatment was performed under the condition of 000 hours was performed, and after the test, a sample in which no foreign matter was generated was evaluated as “good”, and a sample in which foreign matter was generated was evaluated as “defective”.

The stability was defined as "good" if no phenomenon such as an increase in viscosity or phase separation occurred to the extent that molding became difficult when the glass was melted or the glass cullet was re-melted. In addition, although the viscosity did not increase to the extent that molding became difficult at the time of melting or did not cause phase separation, those with a slight increase in viscosity when the glass cullet was re-melted were considered "OK".
And Further, those whose viscosity increased to such an extent that molding was difficult at the time of melting or phase separation were regarded as "defective".

The flowability was determined by molding the glass powder of each sample into a button shape having an outer diameter of 20 mm and a height of about 5 mm using a mold, and then heating it at 330 ° C. for 10 minutes to make it flow.
Good over 1mm, 19mm or more, 21mm
A sample smaller than 19 mm was evaluated as "OK", and a sample smaller than 19 mm was evaluated as "defective".

Tables 5 and 6 show sealing materials obtained by mixing the sealing glass of the above-mentioned embodiment with a refractory filler powder.

[0052]

[Table 5]

[0053]

[Table 6]

The refractory filler of each sample in Tables 5 and 6 was prepared as follows.

The NbZr (PO ₄ ) ₃ filler is prepared by mixing niobium pentoxide, low α-ray zirconia, ammonium dihydrogen phosphate, and magnesia at predetermined ratios, mixing, and then firing at 1450 ° C. for 16 hours. Then, the fired product was pulverized and passed through a 325 mesh stainless steel sieve to obtain a powder having an average particle size of 5 μm.

The cordierite-based filler is composed of magnesium oxide, aluminum oxide and optical stone powder of 2MgO.2A.
formulated such that the ratio of l ₂ O ₃ · 5SiO _2, after mixing, was fired at 1400 ° C. 10 h, then the the calcined product was ground and 250 mesh stainless steel sieve and passed through an average particle size 6μm of did.

The zircon-based filler is obtained by first decomposing natural zircon sand once with soda, dissolving it in hydrochloric acid, and repeating concentration crystallization to obtain extremely high-purity zirconium oxychloride. Z
rO ₂ was obtained. In addition, this purified ZrO ₂ has high purity silica powder,
ZrO ₂ 66% ferric oxide by weight%, SiO ₂ 32
%, ₂ % Fe ₂ O ₃ , and after mixing, firing at 1400 ° C. for 16 hours, then crushing the fired product, passing through a 250 mesh stainless steel sieve, and The thickness was 6 μm.

The cubic zirconia filler is prepared by first converting a high-purity zirconia raw material and calcium carbonate to ZrO ₂ 80
The mixture was prepared so as to have a ratio of 20 mol% of CaO and 20 mol% of CaO, and baked at 1550 ° C. for 16 hours. Thereafter, the fired product was pulverized by a ball mill and passed through a 325 mesh sieve to have an average particle size of 5 μm.

These refractory filler powders are shown in Tables 5 and 6
After mixing with the glass powder for sealing at the ratios shown in Table 1, each sample was obtained by baking.

The thermal expansion coefficient of each sample in Tables 5 and 6 was 52.
4 to 196.5 × 10 ⁻⁷ / ° C., and the sealing temperature is 24
The temperature was as low as 0 to 330 ° C., and the package strength was “good”.

The coefficient of thermal expansion in the table is obtained by molding a fired product fired at the sealing temperature in the table to a size of 40 × 4 mmφ.
It was measured by a quartz push rod type thermal dilatometer.

The sealing temperature was determined by a well-known flow button test. That is, a powder having a weight corresponding to the true specific gravity of each sample was weighed using a mold to an outer diameter of 20 mm and a height of about 5 m.
After molding into a m-shaped button, it was heated and allowed to flow, and the temperature when its outer diameter was about 21 mm was defined as the sealing temperature.

Further, the package strength was evaluated as follows.

First, each sample and a vehicle (0.3% by weight of nitrocellulose in isoamyl acetate solution) were mixed in a weight ratio of 1%.
The mixture was kneaded at a ratio of 0: 1 to obtain a slurry. Next, the obtained slurry was sealed with alumina (coefficient of thermal expansion 70 × 10 ⁻⁷ / ° C.), glass ceramic (coefficient of thermal expansion 120 × 10 ⁻⁷ / ° C.), and window glass as shown in Tables 4 and 5. (Coefficient of thermal expansion 85 × 10 ^-7 / ° C), forsterite (coefficient of thermal expansion 110 × 10 ^-7 / ° C), copper-based alloy (coefficient of thermal expansion 180 × 10 ^-7 ), aluminum nitride (coefficient of thermal expansion 45 × (10 ⁻⁷ / ° C.), and dried at 100 ° C. for 30 minutes. Next, the same kind of plate was placed thereon to prepare a sample, and after baking at a sealing temperature for 10 minutes, the adhesive strength was evaluated. In the evaluation of the adhesive force, each sample was naturally dropped on an oak tree from a height of 1 m, and the sample that did not peel was evaluated as “good”.

[0065]

As described above, the sealing glass of the present invention is excellent in water resistance while being a P ₂ O ₅ glass.
Since the glass is stable, and the sealing material of the present invention using the glass can seal the package at a low temperature of 240 to 330 ° C. without applying a load, the semiconductor integrated circuit is particularly sensitive to heat. It is suitable for sealing a package on which a crystal resonator or the like is mounted.

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Claims (6)

[Claims] 1. A sealing glass which is a P ₂ O ₅ -based glass and contains 0.01 to 20 mol% of Ga ₂ O ₃ . 2. AgI + Ag ₂ O 15 to 8% by mole%
_{5%, P 2 O 5 10~55} %, Ga 2 O 3 0.01~2
0%, TeO ₂ 0-60%, ZnO 0-50%, N
_{b 2 O 5 0~30%, WO} 3 0~30% of the sealing glass according to claim 1, characterized in that it comprises a composition. 3. A sealing glass powder 4 comprising a P ₂ O ₅ glass and containing 0.01 to 20 mol% of Ga ₂ O _3.
A sealing material comprising 5 to 90% by volume and 10 to 55% by volume of a refractory filler powder. 4. The glass powder for sealing has a molar percentage of AgI
+ Ag ₂ O 15 to 85%, P ₂ O ₅ 10 to 55%, G
_{a 2 O 3 0.01~20%, TeO} 2 0~60%, Z
_{nO 0~50%, Nb 2 O 3} 0~30%, WO 3 0
4. The sealing material according to claim 3, having a composition of glass powder for sealing having a composition of about 30%. 5. The glass powder for sealing contains Ag _{2 in} mol%.
O 20-60%, P ₂ O ₅ 20-50%, Ga ₂ O _{3
0.01~20%, TeO 2 + ZnO +} Nb 2 O 5 + WO 3
5. The composition according to claim 4, wherein said composition has a composition of 0 to 70%.
The sealing material as described. 6. The glass powder for sealing is Ag _{2 in} mol%.
O 10-65%, AgI 5-50%, P ₂ O ₅ 10
_{~40%, Ga 2 O 3 0.01~20} %, TeO 2 + Z
_{nO + Nb 2 O 5 + WO} 3 sealing material according to claim 4, characterized in that it has a composition of 0% to 70%.