JPH0372023B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to low-temperature filling and low-temperature bonding using glass, and particularly to a strong water-resistant low-temperature softening glass composition suitable as a filler or bonding material for high-performance magnetic heads that employs amorphous metal. . [Background of the Invention] In recent years, as recording devices have become smaller and recording density has increased, magnetic heads with even better performance have been required. Therefore, the development of high-performance magnetic heads employing amorphous metals having high saturation magnetic flux density is progressing rapidly. The magnetic head has a bonded structure at the magnetic gap, and it has been known that non-magnetic glass is most suitable as a filler or bonding material in terms of longevity. Glass is used as a filler and bonding material for high-performance magnetic heads that use amorphous metal.
It is important that the coefficient of thermal expansion of the glass matches the coefficient of thermal expansion of the material to be filled and bonded. In addition, it goes without saying that the working temperature for filling and bonding must be lower than the heat resistance limit of the material to be filled and bonded, but since high-temperature heating of amorphous metal in particular causes crystallization, the working temperature should be kept as low as possible. The lower the temperature, the better, and if possible, it is desirable to be able to fill and bond at temperatures below 480°C. Furthermore, since magnetic heads are sometimes used in humid environments, if the water resistance of the glass used for the magnetic head is low, the glass may elute, impairing its reliability as a magnetic head. Therefore, glass is required to have strong water resistance that can withstand practical use. Traditionally, this type of glass has been based on PbO-B ₂ O ₃ , which contains a large amount of lead.In this system, the higher the lead content, the lower the temperature you can work with, but the coefficient of thermal expansion is 100 × In addition to exceeding 10 ^-7 /℃,
It has the disadvantage of poor water resistance. On the other hand, if the lead content is reduced, a thermal expansion coefficient of 100×10 ^-7 /℃ or less can be obtained, and the water resistance is improved to some extent, but the disadvantage is that the working temperature for filling and bonding is too high at 500℃ or higher. . For this reason, conventional glasses are not suitable for high-performance magnetic heads employing amorphous metals, and a glass that satisfies the three properties, namely, coefficient of thermal expansion, working temperature, and water resistance, has not yet appeared. This is because the three properties are contradictory, and the development of a new glass that satisfies the three properties has been highly desired not only in magnetic heads but in a variety of other fields. As inventions of glasses containing V ₂ O ₅ , for example, Japanese Patent Application Laid-open Nos. 58-74539, 55-75937, and 54-
There are No. 64514, No. 53-82826, and No. 48-43007.
B ₂ O ₃ −ZnO−V ₂ O ₅ −Bi ₂ O ₃ −Tl 2 _{O 3} glass (Japanese Unexamined Patent Publication No. 1974-74539), Li ₂ O−Na ₂ O−ZnO−B ₂ O ₃ −
V ₂ O ₅ −P ₂ O ₅ −ZrO ₂ −Al ₂ O ₃ -based glass
−64514), Na ₂ O−ZnO−B ₂ O ₃ −P ₂ O ₅ −V ₂ O ₅
glass (JP-A-53-82826) and B ₂ O ₃ −
V ₂ O ₅ −ZnO−Na ₂ O−SiO ₂ −Al ₂ O ₃ −ZrO ₂ glass (Japanese Unexamined Patent Publication No. 48-43007) has a coefficient of thermal expansion of 100×10 ^-7 /°C or less. However, there is a problem in that the working temperature for filling and bonding is high, at over 500℃. PbO−V ₂ O ₅ −P ₂ O ₅ glass (JP-A-55-75937) contains the highest amount of PbO,
It has the advantage of having a low softening point of about 320℃ and strong water resistance, but its coefficient of thermal expansion is about 150×
10 ^-7 /℃, which is a big problem. [Object of the Invention] The object of the present invention is to provide a strong water-resistant low-temperature softening glass composition that has a lower coefficient of thermal expansion than conventional low-temperature softening glass compositions, can be worked at low temperatures, and has excellent water resistance. There is a particular thing. The object of the present invention is to provide a strong water-resistant, low-temperature softening glass composition that is particularly suitable for use as a filler or bonding material for high-performance magnetic heads employing amorphous metal. [Summary of the Invention] To summarize the present invention, the present invention relates to a water-resistant low temperature softening glass composition, which contains 55 to 70% by weight of V ₂ O ₅ and 17 to 17% by weight of P ₂ O ₅ as main components. It is characterized by containing 30% by weight and 2 to 20% by weight of Sb ₂ O ₃ and having a coefficient of thermal expansion of 100×10 ^-7 /°C or less. Furthermore, it is characterized by having the above composition plus 20% by weight or less, preferably 3% by weight or more of PbO, a coefficient of thermal expansion of 70 to 100×10 ^-7 /°C, and a working point of 450°C or less. V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O ₃ −PbO
It also relates to a water-resistant low temperature softening glass composition. Furthermore, 15% by weight or less, preferably 2% by weight or more
Add Tl ₂ O, the thermal expansion coefficient is 80 ~ 100 × 10 ^-7 / °C,
V ₂ O ₅ characterized by a working point below 440℃
_It also relates to _a strong water-resistant low temperature softening glass composition of _-P2O5 - _Sb2O3 -PbO- _Tl2O . Further, adding 5% by weight or less, preferably 0.5% by weight or more of Nb ₂ O ₅ to either of the two types of systems,
Thermal expansion coefficient is 70~95×10 ^-7 /℃, working point is 450℃
V ₂ O ₅ −P ₂ O ₅ − characterized by:
Sb ₂ O ₃ −PbO−Nb ₂ O ₅ system and V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O ₃
-PbO- _Tl2O - _{Nb2O5 -} based strong water-resistant low temperature softening glass composition. In the present invention, the working point means that the viscosity of the glass is approximately
10 The temperature at which the temperature reaches ⁴ poise. The water-resistant low-temperature softening glass composition of the present invention has a coefficient of thermal expansion so small that it can be matched to the coefficient of thermal expansion of the filling material or bonding material of a high-performance magnetic head employing amorphous metal, so that the glass will not break. It is possible to fill and bond without any trouble. In addition, this glass can be heated at 480℃
Since filling and bonding can be performed at a low temperature of below 100, an amorphous metal that does not like heating at high temperatures will not crystallize and can further improve the performance of the magnetic head. Furthermore, the glass of the present invention has good water resistance, so even if a magnetic head filled or bonded with this glass is exposed to high humidity, the glass will not elute, making it possible to create a high-performance magnetic head using amorphous metal. helps improve reliability. As described above, the strong water-resistant low-temperature softening glass composition of the present invention is a novel glass in which the drawbacks of the conventional glasses of this kind described above have been eliminated. Next, various components constituting the strong water resistant low temperature softening glass composition of the present invention and reasons for limiting the composition ranges thereof will be explained. First, V ₂ O ₅ is the main component of a strong water-resistant low-temperature softening glass composition, and is effective in lowering the thermal expansion coefficient and working point of the glass. However, if it exceeds 70% by weight, the water resistance of the glass deteriorates and If it is less than 55% by weight, the coefficient of thermal expansion of the glass will become too large. P ₂ O ₅ is a glass-forming oxide that prevents devitrification of the glass and improves fluidity, but if it exceeds 30% by weight, the working point of the glass becomes too high and the water resistance deteriorates. Moreover, if it is less than 17% by weight, the glass tends to devitrify and cannot be put to practical use. Sb ₂ O ₃ is extremely effective in improving the water resistance of glass, but if it exceeds 20% by weight, the working point of the glass increases too much, and if it is less than 2% by weight, it is not sufficiently effective in improving the water resistance of glass. I can't do it. PbO lowers the working point of the glass and improves its water resistance, but if it exceeds 20% by weight, the coefficient of thermal expansion of the glass becomes too large and it becomes more likely to cause devitrification. Tl ₂ O is added to lower the working point of the glass, but if it exceeds 15% by weight, the coefficient of thermal expansion of the glass becomes too large and the water resistance deteriorates. Nb ₂ O ₅ is added to reduce the coefficient of thermal expansion of the glass, but if it exceeds 5% by weight, the working point of the glass becomes too high and it tends to devitrify. Next, the thermal expansion coefficient of the glass of the present invention ranges from 70 to
Since the temperature is 100×10 ^-7 /°C, it is possible to select a glass suitable for the filling material such as various ferrites and the bonding material, that is, suitable for the magnetic head. Generally, glass with a temperature exceeding 100 x 10 ^-7 /°C will cause cracks in the glass portion after filling or bonding, and will not allow strong filling or bonding, making the magnetic head more likely to break. Further, stress due to the difference in thermal expansion is applied to the magnetic material, deteriorating the magnetic properties of the magnetic head. 70
Glasses with a temperature lower than ×10 ^-7 /°C have not yet appeared in low-temperature softening glasses, but if they did exist, the above-mentioned problems would probably occur. The fact that the working point of glass is 480°C or lower means that glass filling and bonding can be performed at 480°C or lower in the production of magnetic heads.
The ability to work at such low temperatures is most effective for high-performance magnetic heads that employ amorphous metal. If the filling or bonding temperature is high, amorphous metal will crystallize and will not be able to exhibit its performance as a magnetic head. Furthermore, even if the amorphous metal is in a temperature range where crystallization does not occur, the higher the filling temperature or bonding temperature, the shorter the lifespan of the magnetic head, so it is necessary to fill and bond at as low a temperature as possible. There is. In this respect, the glass of the present invention has 440
Since filling and bonding can be performed at low temperatures below 0.9°C, it is possible to produce long-life, high-performance magnetic heads without crystallizing the amorphous metal. Any material may be used as the raw material for the components constituting the glass of the present invention as long as it produces an oxide of the component or a mixture of these oxides upon firing. Next, the method for manufacturing glass of the present invention will be explained. Blend and mix the glass raw materials, place in an alumina crucible or platinum crucible, and heat at 900℃ in an electric furnace at 0.5
Allowed to melt for ~1 hour. This melt was poured into a graphite jig kept at 250 to 300°C, and then cooled in air to produce glass. [Examples of the Invention] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Tables 1 to 5 show the compositions and properties of Examples of the present invention. Table 6 shows the composition and properties of this type of conventional low-temperature softening glass as a comparative example. In addition,
The method for measuring the characteristics of each glass is as follows. (1) Coefficient of thermal expansion Glass processed into a cylindrical shape of 5φ x 20 mm was used as a measurement sample, and was measured in air at a heating rate of 10° C./min using a thermal dilatometer. (2) Softening point and working point The softening point and working point of the powdered glass were measured using a differential thermal analyzer in air at a heating rate of 10°C/min. The softening point and working point here correspond to viscosities of about 10 ^7.6 poise and about 10 ⁴ poise. (3) Water resistance A piece of glass processed into a cube of 5 x 5 x 5 mm.
Place in 40c.c. distilled water and heat at 70℃ for 2 hours.
Thereafter, the glass pieces were thoroughly dried and weight loss was measured. The water resistance here is a value calculated in mg of weight loss per 1 g of sample under the above conditions.

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〔Effect of the invention〕

The present invention is similar to conventional low-temperature softening glass.
The composition is not PbO as the main component, but a V _{2 O 5 -P 2} O ₅ -Sb ₂ O ₃ system with V 2 O ₅ as the main component, and has a thermal expansion coefficient of 100 × 10 ^-7 / It is a glass that achieves three effects at the same time: it is small at less than °C, has a low working point, and is highly water resistant. Therefore, it is particularly suitable as a high-performance magnetic head material or bonding material that uses amorphous metal in low-temperature filling or bonding using glass at temperatures below 480°C. The V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O−PbO system with PbO added has a thermal expansion coefficient of 70 to 100×10 ^-7 /°C, and the working point can be lowered to 450°C or lower, and A strong water-resistant low-temperature softening glass that can improve water resistance is obtained. V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O−PbO ₃ with further addition of Tl ₂ O
-In the Tl ₂ O system, the thermal expansion coefficient is 80 to 100 × 10 ^-7 /℃
This results in a highly water-resistant, low-temperature softening glass that can be lowered to a working point of 440°C or lower. Using this type of glass, it is possible to perform filling and bonding at low temperatures below 440°C, which is extremely effective for materials that do not have heat resistance, such as amorphous metals. V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O ₃ − with further addition of Nb ₂ O ₅
PbO−Nb ₂ O ₅ system and V ₂ O ₅ −P ₂ O ₅ −Sb ₂ O ₃ −PbO
−Tl ₂ O− Na ₂ O ₅ system has a coefficient of thermal expansion of 70 to 95 ×
A highly water-resistant, low-temperature softening glass with a lower temperature of 10 ^-7 /°C and a working point of 450°C or less can be obtained. This type of glass can be used particularly effectively when a material with a small coefficient of thermal expansion is used as a filling material or a bonding material. The low-temperature softening glass of the present invention simultaneously satisfies the three properties of low expansion, low melting point, and strong water resistance, significantly exceeding the properties of conventional glass, and is an epoch-making glass that has not yet appeared in the world. Such glasses are highly desired in various fields as filling, bonding and sealing glasses. In addition, it can also be used for general magnetic heads and LSI packages. Broadly speaking, it is effective for low-temperature bonding to ceramics. When used as a filler and bonding material for general magnetic heads, it has the advantage of being able to work at low temperatures and can be effectively used for all kinds of magnetic heads. It can be effectively used as a sealing glass for LSI packages, especially packages using high thermal conductivity SiC. Currently, this sealing glass is made of PbO glass, which has high expansion and low melting point, and contains a large amount of filler, which is a low expansion material, but the glass of the present invention can be sealed with a small amount of filler or without filler. It can be sealed at a lower temperature than before, and it has excellent water resistance, so the package can be used even in high humidity. It is known that the wettability with SiC is not bad. As described above, it can be effectively used for low-temperature filling, low-temperature bonding, and low-temperature sealing of materials with relatively low expansion.

Claims (1)

[Claims] 1. 55 to 70% by weight of V ₂ O ₅ as the main component;
A water-resistant low-temperature softening glass composition containing 17 to 30% by weight of P ₂ O ₅ and 2 to 20% by weight of Sb ₂ O ₃ and having a coefficient of thermal expansion of 100×10 ⁻⁷ /° C. or less. 2 further contains 20% by weight or less of PbO as a component,
Thermal expansion coefficient is 70~100× ^10-7 /℃, working point is 450℃
The water-resistant low-temperature softening glass composition according to claim 1, which is as follows. 3 further contains 15% by weight or less of Tl ₂ O as a component,
Thermal expansion coefficient is 80~100×10 ^-7 /℃, working point is 440℃
The water-resistant low temperature softening glass composition according to claim 2, which is as follows. 4 Contains 5% by weight or less of Nb ₂ O ₅ as a component, has a thermal expansion coefficient of 70 to 95×10 ^-7 /℃, and has a working point of
Claim 2 or 3 that the temperature is 450°C or less
The water-resistant low-temperature softening glass composition described in 1.