JPH11130462A - Glass composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a glass compsn. having satisfactory water resistance, capable of adhesion and sealing at a relatively low temp. and contg. no harmful element. SOLUTION: The glass compsn. contains >=71 wt.%, in total, of 50-70 wt.% P2 O5 , 20-40 wt.% SrO and 1-15 wt.% Al2 O3 or may further contain <=29 wt.%, in total, of 0-5 wt.% at least one of Nb2 O5 and Ta2 O5 , 0-5 wt.% one or more selected from the group comprising SiO2 , GeO2 , TiO2 and ZrO2 , 0-5 wt.% at least one of B2 O3 and Ga2 O3 , 0-10 wt.% one or more selected from the group comprising MgO, CaO, BaO, ZnO and FeO, 0-5 wt.% one or more selected from the group comprising Li2 O, Na2 O and K2 O and 0-5 wt.% (expressed in terms of fluorine) source of fluorine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass composition used for, for example, bonding or sealing electronic parts or components thereof, glass enamel and the like.

[0002]

2. Description of the Related Art In general, bonding of electronic parts with glass,
Alternatively, sealing can be used to avoid thermal degradation of component performance.
Therefore, it is desirable to work at the lowest possible temperature.
In particular, low-temperature fusing glass has been developed and used
I have. By the way, conventionally used glass
Is PbO-B containing a large amount of lead harmful to the human body_TwoO_Three, PbO
-B _TwoO_Three-ZnO, PbO-B_TwoO_Three-SiO_Two-Na_TwoO, PbO-B_TwoO_Three-SiO_Two-BaO system
Most of the compositions are based on
V with low lead content_TwoO_Five-P_TwoO_Five-Sb_TwoO_Three-PbO-based composition, etc.
Is used. However, lead oxide (PbO) content
The more the glass, the lower the melting of the glass.
Typically, a composition rich in lead oxide (PbO) is selected.

On the other hand, low melting glass which does not contain environmentally harmful lead
Compositions are also known. For example, Na_TwoO-B_TwoO_Three, K_TwoO-B
i_TwoO_Three-B_TwoO_Three, Na_TwoO-B_TwoO_Three-P_TwoO_Five, ZnO-SnO-P_TwoO_Five, Na_TwoO-B_TwoO_Three
-GeO _Two, TeO_Two-MoO_Three-V_TwoO_Five, GeO_Two-P_TwoO_Five-V2O_Five, B_TwoO_Three-Bi_TwoO_Three,
 ZnO-B_TwoO_Three-Ti_TwoOxide-based oxides,
Compounds, fluorides, chalcogens, etc.
Literature or patent publications for bonding or sealing products
It is stated in the report.

As a composition system containing a phosphate, the above-mentioned V_Two
O_Five-P_TwoO_Five-Sb_TwoO_Three-PbO, Na_TwoO-B_TwoO_Three-P_TwoO _Five, ZnO-SnO-P_TwoO_Five, G
eO_Two-P_TwoO_Five-V_TwoO_FiveIn addition to the system based on_TwoO_Five-ZnO-R'O-R
_TwoO system (R 'is an alkaline earth metal element, mainly Mg
Or Ba and R are alkali metal elements, mainly Li)
ing. However, in all phosphate systems, SrO
Does not contain 20% by weight or more.

[0005]

The lead-free glass based on the above system has a low melting point, but is not necessarily suitable for use in terms of thermal expansion coefficient and water resistance. Absent. Above all, provision of a glass composition containing not only lead but also harmful elements such as cadmium, bismuth, antimony, and thallium has become an urgent issue in environmental conservation.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide, in view of the above-mentioned problems, good water resistance, adhesion and sealing at a relatively low temperature,
Moreover, it is an object of the present invention to provide a glass composition containing no harmful elements.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the feature of the present invention is that P ₂ O ₅ 50
70 wt%, SrO 20 to 40 wt%, Al ₂ O ₃ 1~15
The glass composition containing a total of 71% by weight or more can be melted by an ordinary method.
The average coefficient of thermal expansion between ~ 300 ° C is approximately 120 × 10-7 /
It is found that bonding and sealing can be performed at a relatively low temperature of 600 to 650 ° C. at a temperature of not more than 600 ° C.

[0008] In the present invention, to improve the chemical properties and the like
And Nb_TwoO_FiveOr Ta_TwoO_FiveAt least one of 0 to 5 weight
%, SiO_Two, GeO_Two, TiO_Two, ZrO_TwoOne selected from the group consisting of
0 to 5% by weight of seed or more, B_TwoO_ThreeOr Ga_TwoO_ThreeAt least one of
0 to 5% by weight, consisting of MgO, CaO, BaO, ZnO, FeO
0 to 10% by weight of at least one selected from the group, Li_TwoO, Na
_TwoOK _Two0-5 weight of at least one selected from the group consisting of O
%, The fluorine source is 0 to 5% by weight in terms of fluorine, and
It may contain up to 29% by weight in total.

[Function of Glass Constituents] The glass constituents are limited to the above composition range for the following reason.
Under the condition that no harmful elements such as lead, cadmium, bismuth, antimony, and thallium, and components commonly used as low-melting glass components such as vanadium, molybdenum and tungsten, are used at all. In order to obtain a melting glass, it is preferred to be based on a phosphate system. Furthermore, considering water resistance,
A composition in which the content of the alkali metal oxide is minimized is desirable. The present invention relates to a method for producing P ₂ O ₅ and an alkaline earth metal oxide.
It is based on the discovery that, in the phase equilibrium diagram, the P ₂ O ₅ -SrO system has a considerably wide range of low melting points in the component system, and that glass can be obtained in that range.

When P ₂ O ₅ -SrO is used as a basic component, phosphorus pentoxide (P ₂ O ₅ ) is a glass forming component. Therefore,
If the amount is too small, the glass becomes remarkably unstable against crystallization, tends to be devitrified at the time of producing the glass, or tends to precipitate crystals during the bonding or sealing operation to hinder the adhesion to the adherend. In order to obtain a glass that is stable enough to meet the purpose of use at the time of making the glass or at the working temperature, 50
% Is the lower limit. On the other hand, when the P ₂ O ₅ component is increased, the glass is obtained and cheaper, but deteriorates the water resistance and increases the coefficient of thermal expansion. For the purposes of the present invention, 70% is the upper limit.

The strontium oxide (SrO) is P ₂ O ₅
In the system based on the two components of the alkaline earth metal oxide and the alkaline earth metal oxide, it is a conceivable optimum alkaline earth metal oxide from the viewpoint of stability against devitrification and water resistance. However, if the amount is too small, the water resistance of the glass is unsatisfactory, and if it is too large, crystals are precipitated and cannot be obtained as glass. Therefore, 20 to 40% by weight is appropriate.

The total amount of P ₂ O ₅ and SrO is at least 70% by weight.
This is because, in the system based on the two components of P ₂ O ₅ and SrO, it is difficult to obtain a satisfactory glass if the ratio is not in the range from the viewpoint of low melting property and devitrification. But P ₂
Glasses containing only O ₅ and SrO are still unsatisfactory in terms of practicality. In order to improve it, the content of a small amount of Al ₂ O ₃ is essential. Al ₂ O ₃ works to strengthen the glass network structure of glass containing P ₂ O ₅ as a glass-forming component, and improves stability against devitrification and water resistance, and also suppresses an increase in thermal expansion coefficient. However, the effect is not remarkably exhibited unless the content is 1% by weight or more. The higher the content, the better the stability against devitrification and the water resistance are. However, if the content is too high, the low melting property is impaired, and eventually melting becomes difficult. Therefore, 1 to 15% by weight is appropriate for the purpose of the present invention.

The above P_TwoO_Five , SrO and Al_TwoO_ThreeIn addition to the three ingredients
As long as the total amount is less than 29% by weight,
To improve the properties, a small amount of additives, namely Nb2O_Fiveor
Is Ta2O _FiveAt least one of 0 to 5% by weight, SiO_Two, Ge
O_Two, TiO_Two, ZrO_Two0 or more selected from the group consisting of
~ 5% by weight, B_TwoO_ThreeOr Ga_TwoO_ThreeAt least one of 0 to 5
% By weight, selected from the group consisting of MgO, CaO, BaO, ZnO, FeO
0 to 10% by weight, Li_TwoO, Na_TwoOK_TwoFrom O
0 to 5% by weight of at least one selected from the group consisting of a fluorine source
From 0 to 5% by weight in terms of fluorine.
You.

Of these, at least one of Nb ₂ O _{5 and} Ta ₂ O ₅ mainly contributes to improvement of the water resistance of the glass. If the amount is too high, the low melting property is hindered, and the tendency to devitrify is increased. Therefore, 0 to 5% by weight is appropriate.

The above-mentioned SiO ₂ , GeO ₂ , TiO ₂ , ZrO _{2 and the} like are involved in the formation of a glass network structure, and when the amount is not too large, they work to strengthen the glass structure and weaken the devitrification. But too much will have the opposite effect. Therefore, the maximum is 5% by weight.

The effect of at least one of B ₂ O _{3 and} Ga ₂ O ₃ on the structure of the phosphate glass is similar to that of Al ₂ O ₃ . However, since B ₂ O ₃ itself is soluble in water, too much B adversely affects water resistance. On the other hand, Ga ₂ O
_The effect of ₃ on the glass structure is milder than that of Al ₂ O ₃ or B ₂ O ₃ , but since it is expensive, it is not advisable to include a large amount. Therefore, for these reasons, 0 to 5% by weight is appropriate.

Since MgO, CaO, BaO, ZnO, FeO and the like are divalent oxides, their chemical properties are similar to those of SrO in many cases, and are considered to complement the effect of SrO in glass. Of these, the introduction of an appropriate amount of ZnO
It has a particularly favorable effect on the water resistance, devitrification resistance and viscous behavior during bonding of the glass while maintaining low melting properties. Therefore, a suitable range is 0 to 10% by weight.

In many cases, the content of an alkali metal element in a glass for bonding electronic parts is reluctant, but if the content is permitted, the content of Li ₂ O, Na ₂ O, 5% by weight or less is limited.
One or more selected from the group consisting of K ₂ O can be included. This is because the proper selection of the above components of 5% by weight or less contributes to improvement of the glass against devitrification without adversely affecting water resistance and low melting property.

At least one of B ₂ O _{3 and} Ga ₂ O ₃ , at least one selected from the group consisting of MgO, CaO, BaO, ZnO and FeO, and at least one of Li ₂ O, Na ₂ O and K ₂ O In phosphate composite compositions containing one or more selected from the group, a small amount of boron can be added because it can have a positive effect on the water resistance and viscous behavior of the glass. However, the amount is at most 5% by weight.

Glass suitable for bonding and sealing electronic components can be suitably diverted for glass enamel as well as the glass of the present invention.

It is inevitable that a small amount of water (many of which is in the form of -OH) remains in the phosphate glass melted by a usual method. The composition range specified in the present invention is a value ignoring the amount of remaining water, and even if a small amount of water is present, it does not essentially hinder the present invention. In addition, although Fe is thought to exist in a trivalent form in addition to divalent form, for simplicity, it is shown that all Fe exists in a divalent form.

[Effects of the Invention] As described above, according to the present invention, a composition system completely different from the conventionally used glass for bonding or sealing or the glass for enamel, P ₂ O ₅ -SrO-Al ₂ O ₃ system, it is possible to provide an adhesive for glass. Since this glass does not contain any toxic elements of heavy metals such as cadmium and lead, it can be used to perform bonding, sealing, or enamelling of electronic components with less concern for the environment. be able to.

[0023]

EXAMPLE An alumina crucible was charged with a predetermined amount of orthophosphoric acid,
A raw material composed of an oxide, a hydroxide, a carbonate, and a fluoride was added, and after the initial foaming, the mixture was gradually heated to 400 ° C. and calcined at that temperature for 2 hours. Thereafter, the temperature was further raised, and the temperature was kept at 1000 to 1200 ° C. for 1 hour to completely melt. The melt was poured out onto a stainless steel plate, and gradually cooled to remove distortion. And various physical properties were measured about the obtained glass.

Table 1 shows composition examples and physical properties of the glass thus implemented, together with comparative examples. In the table, the glasses of Examples 1 to 10 in the composition of the present invention are glasses that can be used for bonding and sealing at 600 to 650 ° C. or lower, while the glass of Example 11 outside the scope of the present invention is used. The compositions Nos. To 14 are unsuitable for adhesion or sealing at 650 ° C. or lower for some reason such as water resistance, fluidity, and devitrification.

[0025]

[Table 1]

[Remarks] In Table 1, the number of each component in the composition is% by weight calculated from the batch, and the amount of water that may remain is ignored. The above At (° C.)
The temperature corresponding to the yield point on the TMA curve. The water resistance is measured by measuring a loss in boiling by a method for measuring the chemical durability of an optical glass (powder method). If it is approximately 0.2% or less, it can be used depending on the purpose of use, and if it is> 1.0%, it indicates that the water resistance is too poor to be used. Regarding the adhesiveness, the particles of the sample glass were placed on a piece of plate glass, heated at 600 to 650 ° C. for 10 minutes, and then the fluidity of the sample glass was observed. Poor fluidity results in poor adhesion and cannot be used. The poor adhesion is as follows.
This indicates that crystals were precipitated during the observation of fluidity, resulting in poor fluidity. The term "devitrification" in the column of adhesiveness indicates that melting was impossible or the melt was devitrified during cooling, and a satisfactory glass was not obtained. In any case, uniform adhesion is hindered,
It cannot be used for the purpose of the present invention. After all, P ₂ O ₅ :
It turns out that the ratio of SrO = 75 ± 10: 25 ± 10 is appropriate.

Claims (2)

[Claims] 1. A glass composition comprising 50 to 70% by weight of P ₂ O ₅ , 20 to 40% by weight of SrO, and 1 to 15% by weight of Al ₂ O ₃ in a total amount of 71% by weight or more. Wherein Nb2O ₅ or at least one of the 0-5 wt% of _{Ta 2 O 5, SiO 2,} GeO 2, TiO 2, selected from the group consisting of ZrO ₂ one or more 0-5 wt%, B ₂ O ₃ or Ga ₂ O ₃ of at least one 0-5 wt%, MgO, CaO, BaO, ZnO,
Selected from the group consisting of FeO one or more 0-10 _{wt%, Li 2 O, Na 2} O, K 2 O selected from the group consisting of one or more 0-5 wt%, the fluorine conversion value to fluorine source The glass composition according to claim 1, further comprising 0 to 5% by weight, and a total of 29% by weight or less.