Leadless low-melting glass powder for seal with metal or alloy and preparation method thereof

Abstract

The invention relates to lead-free glass powders with low melting point for sealing of metal or alloy and preparation methods thereof. The glass powder comprises P2O5, ZnO, Al2O3, SiO2, MgO, MnO2, Li2O, WO3, CaF2, Na2O, K2O and CaO. The preparation thereof is divided into the following steps: (1) raw materials are drawn and fully mixed according to weight proportions to make into mixed materials; (2) the mixed materials are heated and melted for 30 minutes to two hours under a temperature ranging from 1000 DEG C to 1350 DEG C; (3) the melted glass liquid is cooled and cured into glass body. The glass powder not only has comparatively ideal heat expansion coefficient, softening temperature and chemical stability but also has simple preparation process, straightforward operation and low cost, which is applicable to the sealing of glass, ceramic, metal and semiconductor and in particular applicable for the sealing of metals of molybdenum family and tungsten family or alloy such as kovar alloy. Also the glass powder is competitive in lead-free production and has wide market development prospect.

Description

technical field [0001] The invention belongs to the field of glass powder and its preparation method, in particular to a lead-free low-melting glass powder for sealing with metal or alloy and its preparation method. Background technique [0002] Sealing glass is an advanced welding material. This material has a more suitable melting temperature and sealing temperature, good heat resistance and chemical stability, and high mechanical strength. It is widely used in electric vacuum and microelectronics technology, Laser and infrared technology, high-energy physics, energy, aerospace, automobiles and many other fields have realized mutual sealing between glass, ceramics, metals and semiconductors. Applied products include cathode ray tube displays, vacuum fluorescent displays, plasma displays, vacuum glass, solar collector tubes, lasers, magnetic material heads and magnetic material films, etc. [0003] In low-melt sealing glass, lead-containing sealing glass has a series of ch...

AI Technical Summary

Problems solved by technology

The softening temperature of the glass is 400-430°C, and the coefficient of thermal expansion is 145-170×10 -7 / °C, although the softening temperature of the glass is suitable for low-melt sealing, but the content of alkali metal oxides is high, resulting in poor chemical stability and electrical properties. In addition, the glass has a large thermal expansion coefficient and cannot be used for medium and The seal with low expansion coefficient contains a small amount of lead at the same time, so it cannot meet the requirements of lead-free

In addition, due to the noble metal ZrO 2 The content is relatively high, so there is also no advantage in terms of cost

[0011] U.S. Patent P5153151 discloses a phosphate sealing glass whose molar composition is Li 2 O 0~15%, Na 2 O 0~20%, K 2 O 0~10%, ZnO 0~45%, Ag 2 O 0~25%, Tl 2 O 0~25%, PbO 0~20%, CuO 0~5%, CaO 0~20%, SrO 0~20%, P 2 o 5 24~36%, Al 2 o 3 0~5%, CeO 2 0~2%, BaO 0~20%, SnO 0~5%, Sb 2 o 3 0~61%, Bi 2 o 3 0~10%, B 2 o 3 0-10%, the transition temperature of the glass is 300-340°C, and the coefficient of thermal expansion is 135-180×10 -7 / °C, but the disadvantage of this glass is the larger Tl 2 O toxicity and thermal expansion coefficient, can not be used for medium and low expansion coefficient sealing

[0012] U.S. Patent US20020019303 proposes a sealing glass of phosphorus-tin-zinc system with a sealing temperature of 430°C to 500°C, but because it contains a large amount of SnO, it needs to be produced and sealed in a reducing atmosphere, which is not conducive to industrial application, and The cost is relatively expensive, therefore, the application of this sealing glass has great limitations

[0013] The mole percentage of the glass composition disclosed in Japanese Patent No. H7-69672 is: P 2 o 5 25~50%, SnO 30~70%, ZnO 0~25%, on this basis, add B 2 o 3 、WO 3 , Li 2 O, etc., the transition temperature of the glass is 350-450°C, and the coefficient of thermal expansion is greater than 120×10 -7 / °C, the method of using fillers in the patent reduces the expansion coefficient of the glass, but affects the fluidity and airtightness of the glass when sealing

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