CN101289279A - Vanadates leadless low-temperature sealing glass material and method for preparing same - Google Patents

Abstract

The invention relates to a vanadate-system lead-free low temperature sealing glass material and a preparation method thereof. The components of the sealing glass material by mol percentage are as follows: 25 percent to 55 percent of V2O5, 5 percent to 20 percent of B2O3, 5 percent to15 percent of ZnO, 20 percent to 50 percent of TeO2 and 2 percent to 15 percent of an alkali metal oxide R2O. The preparation method of the invention comprises the steps that vanadium pentoxide, boric acid, zinc oxide, tellurium dioxide and alkali metal carbonate are adopted as raw materials; the weight percentages of the raw materials are calculated according to the mol percentage of each component of the sealing glass; the raw materials are then weighted and evenly mixed to be placed in a corundum crucible and fused under the temperature of 800 to 900 DEG C; molten glass is then cast for formation or ground into powder after being treated with water quenching and the powder is then filtered by a 200-mesh sieve. The sealing glass material of the invention contains no toxic and harmful substances such as lead, cadmium, thallium, and the like, and has the advantages of low temperature for sealing, the minimum temperature reaching 300 DEG C, and good chemical stability, and is especially applicable to the sealing of electronic components.

Description

A kind of Vanadates leadless low-temperature sealing glass material and preparation method thereof

Technical field

The present invention relates to a kind of Vanadates leadless low-temperature sealing glass material and preparation method thereof, belong to technical field of electronic materials.

Background technology

The low temperature seal glass is meant that fusing point significantly is lower than the seal glass of simple glass, it can be used as a kind of solder application in vacuum technique and electronic technology, uses unorganic glass than using organic dielectric in the no shell sealing of semiconductor instrument instrument and has more obvious superiority at aspects such as environmental protection, aging, protection against the tide, soundnesses.

It is at present, domestic that main in low temperature seal glass field that adopt is PbO-B ₂O ₃-SiO ₂, PbO-ZnO-B ₂O ₃Etc. system.Flint glass has a series of well-known advantages, and is little as dielectric loss, softening temperature is low, chemical stability is good etc.But along with the enhancing gradually of people's environmental consciousness, plumbous to the mankind murder by poisoning and to the pollution of environment, more and more cause the attention of each side, for this reason, as far back as 1992, US Congress proposed the Reid bill, banned use of leaded material more exactly in the electronic tissue industry.European Union in 1998 proposes to completely forbid the leaded electronic solder of use from January 1st, 2004 by WEEE and the 2nd draft resolution of RoHS, postpones afterwards on January 1st, 2008.On January 27th, 2003, European Union passed through the 2002/96/EC bill, and clearly regulation WEEE and RoHS instruction came into force from February 13rd, 2003, and the related products of selling on the European market from July 1st, 2006 is necessary for lead-free product.

V ₂O ₅System glass mainly comprises V ₂O ₅-P ₂O ₅, V ₂O ₅-TeO ₂Deng system glass, they compare PbO-B ₂O ₃System's fusing point is low, is 400 ℃ of bonding topmost materials of following resistance to air loss.PbO-V as NEG USP 5,116,786 propositions ₂O ₅-TeO ₂System glass, all below 300 ℃, its sealing temperature is about 350 ℃ for Tg in the embodiment.

At present, in electronic devices and components sealing-in field, needing sealing temperature as IC semi-conductor chip ceramic package sealing is seal glass about 300 ℃, but present environmental protection (does not contain lead, hazardous and noxious substances such as cadmium and thallium) seal glass is difficult to reach requirement, particularly along with the development of advanced person's semiconducter device (as gallium arsenide) and the extensive application of corresponding III-V compounds of group multilayer semiconductor device (as laser diode), sealing glass is proposed a urgent requirement, requirement can seal bonding 300 ℃ or lower temperature, the requirement as United States Army standard MILSPECS883 just has.

Can be subjected to strictness restriction aspect the raw material 300 ℃ and following sealed glass, the available oxide compound is few, requires glass should possess following character:

1) forms real glass metal, not crystallization;

2) low melting point:

3) glassy phase is stable;

4) coefficient of expansion is suitable;

5) chemical stability is good.

Patent in this respect mainly contains:

The USP 4,743,302 that U.S. VLSI packaged material company discloses, it can be at 320 ℃ of short period of time encapsulated semiconductor device shells, and thermal expansivity is 100～140 * 10 ^-7℃ ^-1, being specially adapted to aluminum oxide or beryllium oxide ceramics shell, its mass percent compositing range is: 35～45% PbO, 35～45% V ₂O ₅, 3～8% Bi ₂O ₃, 2～7% ZnO, 0～5% P ₂O ₅, 0～8% Ta ₂O ₅, 0～5%Nb ₂O ₅, P ₂O ₅+ Ta ₂O ₅+ Nb ₂O ₅Be no more than 0.1～10%.

The USP 5,336,644 that U.S. Johnson Ma Sai company (Johnson Matthey Inc.) discloses, it can be at the ceramic package of 300～350 ℃ of sealing chips, and best in quality percentage ratio compositing range is: 25～45% Tl ₂O, 20～30% V ₂O ₅, 3～10% As ₂O ₃, 10-20 TeO ₂, 2% P ₂O ₅

U.S. Pat P 4,933, and 030 proposes a class Tl ₂O-V ₂O ₅-P ₂O ₅System glass, best compositing range mass percent is Tl ₂O:69～74%, V ₂O ₅: 16～22%, P ₂O ₅: 7～10%.Best filling silver paste compositing range mass percent is a flakey silver powder (tensio-active agent is arranged) 70～72%, glass powder 18～22%, organic carrier 10～12%.The actual measurement bonding temp is 300～365 ℃, time 5min.

It is exactly to contain a large amount of PbO and Tl that all above patents all have a common shortcoming ₂Toxic substances such as O, therefore, very low temperature environmental protection (do not contain hazardous and noxious substances such as lead, cadmium and the thallium) sealing glass material of exploitation sealing temperature about 300 ℃ is extremely urgent.

Summary of the invention

The purpose of this invention is to provide Vanadates leadless low-temperature sealing glass material of a kind of environmental protection and preparation method thereof.

Vanadates leadless low-temperature sealing glass material of the present invention, its component and mole percent level are:

V ₂O ₅ 25～55％，

B ₂O ₃ 5～20％，

ZnO 5～15％、

TeO ₂ 20～50％，

Alkalimetal oxide R ₂O 2～15%.

Above-mentioned alkalimetal oxide R ₂O can be Li ₂O, Na ₂O and K ₂The mixing of one or more among the O.

The preparation method of Vanadates leadless low-temperature sealing glass material, step is as follows:

1) with Vanadium Pentoxide in FLAKES, boric acid, zinc oxide, tellurium dioxide and alkaline carbonate are raw material, according to the oxide compound prescription molecular fraction V of seal glass ₂O ₅25～55%, B ₂O ₃5～20%, ZnO5～15%, TeO ₂20～50%, R ₂O 2～15%, calculate the mass percent of raw material, and raw materials weighing mixes;

2) raw material after will mixing is put into corundum crucible, founds under 800-900 ℃ melt temperature, is incubated 20～60 minutes;

3) will pulverize after the glass metal cast molding that melt or the shrend, the glass powder particle is crossed 200 mesh sieves, obtains the seal glass powder.

The oxide raw material of seal glass: V ₂O ₅Introduce by analytically pure Vanadium Pentoxide in FLAKES; B ₂O ₃Introduce by analytically pure boric acid; ZnO is introduced by analytically pure zinc oxide; TeO ₂Introduce by analytically pure tellurium dioxide; Basic metal is introduced by analytically pure alkaline carbonate, and said alkaline carbonate can be Quilonum Retard, yellow soda ash or salt of wormwood.

In the present invention, V ₂O ₅Be the crucial oxide compound that reduces this glass system softening temperature, its molecular fraction content is 25～55%, preferred 30～50%.Vanadium ion is with VO ₆Octahedral form enters into the network structure of glass, and vanadium is polarized easily, is also shielded by oxygen anion easily, so vanadate glass has extremely low glass melting temperature.When its content less than 25% the time, can not reduce the softening temperature of glass fully, can not reach the effect of anticipation; And when its content greater than 55% the time, vanadate glass chemical temperatures variation, crystallization extremely easily causes the flowability of glass to reduce simultaneously, can not finish sealing-in.

TeO ₂Be the network modification body of this glass, its molecular fraction content is 20～50%, preferred 25～45%.When its content less than 20% the time, then glass instability, crystallization easily; And when its content was higher than 50%, then its glass transformation temperature raise.

ZnO and B ₂O ₃Adding improved the chemical stability of this system glass greatly, also improved the transition temperature of glass simultaneously, suitable molecular fraction content is respectively 5～15% and 5～20%.

In the present invention, alkalimetal oxide R ₂The adding of O can improve the flowability of glass, reduces glass transformation temperature, can reduce the thermal expansivity of glass again, and along with the rising gradually of its content, basic metal mainly plays the suspension effect in glass network, increased thermal expansivity greatly, alkalimetal oxide R ₂The molecular fraction content that O is suitable is 2～15%.

The advantage of Vanadates leadless low-temperature sealing glass material of the present invention is: the feature of environmental protection is good, and hazardous and noxious substances such as not leaded, cadmium and thallium greatly reduces the harm of traditional seal glass to environment and human body; Sealing temperature is low, minimumly reaches 300 ℃, has both reduced the energy consumption of sealing-in process, again to being played a very good protection by closure; Chemical stability is good, and thermal expansivity is adjustable within the specific limits, is specially adapted to the sealing-in of electronic devices and components.

Embodiment

The present invention is described in further detail below in conjunction with specific embodiment.

Embodiment 1

1) with Vanadium Pentoxide in FLAKES, boric acid, zinc oxide, tellurium dioxide and alkaline carbonate are raw material, according to the molecular fraction content of each component of seal glass, calculate the mass percent of raw material, raw materials weighing mixes;

2) raw material after will mixing is put into corundum crucible, founds under 800-900 ℃ melt temperature, is incubated 20～60 minutes;

3) will pulverize after the glass metal cast molding that melt or the shrend, the glass powder particle is crossed 200 mesh sieves, obtains the seal glass powder.

Table 1 has provided the prescription of 7 specific embodiments of sealing glass material of the present invention and the test result of gained sample, and described composition is mol%.

Testing method is: the transition point Tg of glass, thermalexpansioncoefficient record in same high-temperature horizontal expands view, and sample size is 6 * 6 * 50mm ³The water resistance test of glass carries out in 90 ℃ distilled water, will wear into 10 * 10 * 10mm ³Sample be placed in 90 ℃ the distilled water water-bath 24 hours.

Table 1

By table 1 as seen, the glass transition point temperature T g of seal glass of the present invention is 210～255 ℃, and sealing temperature Ts is 300～350 ℃, and thermalexpansioncoefficient is 110～130 * 10 ^-7℃ ^-1Adjustable in the scope.

Claims (4)

1. Vanadates leadless low-temperature sealing glass material is characterized in that its component and mole percent level are:

V ₂O ₅ 25～55％，

B ₂O ₃ 5～20％，

ZnO 5～15％，

TeO ₂ 20～50％，

Alkalimetal oxide R ₂O 2～15%.

2. Vanadates leadless low-temperature sealing glass material according to claim 1 is characterized in that said alkalimetal oxide R ₂O is Li ₂O, Na ₂O and K ₂The mixing of one or more among the O.

3. the preparation method of a Vanadates leadless low-temperature sealing glass material as claimed in claim 1 is characterized in that step is as follows:

1) with Vanadium Pentoxide in FLAKES, boric acid, zinc oxide, tellurium dioxide and alkaline carbonate are raw material, according to the oxide compound prescription molecular fraction V of seal glass ₂O ₅25～55%, B ₂O ₃5～20%, ZnO 5～15%, TeO ₂20～50%, R ₂O 2～15%, calculate the mass percent of raw material, and raw materials weighing mixes;

2) raw material after will mixing is put into corundum crucible, founds under 800-900 ℃ melt temperature, is incubated 20～60 minutes;

3) will pulverize after the glass metal cast molding that melt or the shrend, the glass powder particle is crossed 200 mesh sieves, obtains the seal glass powder.

4. the preparation method of Vanadates leadless low-temperature sealing glass material according to claim 1 is characterized in that said alkaline carbonate is Quilonum Retard, yellow soda ash or salt of wormwood.