Structure of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glass

Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses.The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC,FT-IR,XRD and SEM.The results show that with the increase of B2O3 content,the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase,which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass.With increasing the heat treatment temperature,a large number of liquid phases appear in samples and the sinter efficiency of the samples increases.The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi-O bond from [BO3] pyramidal and [BiO6] octahedral units and B-O from [BO3] and [BO4] units.With the decrease of B2O3 content,the crystallization tendency of the glass increases.In glass samples B1 and B2,crystallization starts at 460℃ and 540℃,respectively.Both of them precipitate Bi24B2O39 phases.

Effect of Kovar alloy oxidized in simulated N_2/H_2O atmosphere on its sealing with glass

The effect of Kovar alloy oxidized in simulated field atmosphere on its sealing with glass was studied in this article. After Kovar plates and pins were preoxidized in N2 with 0℃, 10℃ and 20℃ dew points at 1000℃ for different times, Fe304 and Fe203 existed in the oxidation products on Kovar surface, and the quantity of Fe203 increased with increasing dew point and oxidation time. Then they were sealed with borosilicate glass insulator at 1030℃ for 20 rain. The results indicated that the type and quantity of oxidation products would directly influence the quality of glass-to-metal seals. With the increase of oxidation products, gas bubbles in the glass insulator were more serious, the climbing height of glass along the pins was higher, and corrosion of Kovar pins caused from the molten glass was transformed from uniform to the localized.

Melting, sintering and wetting properties of ZnO–Bi_2O_3–B_2O_3 sealing glass

Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological behavior of ZnO-Bi_2O_3-B_2O_3 system glass melt,the properties of viscosity,thermal expansion,fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer,dilato meter and high-temperature microscope.The structure of sintered glass samples was investigated with scanning electron microscope.The results show that the B_2O_3 content increasing in B_1-B_3 at the given temperature between 400 ℃ and 500 ℃ leads to the increasing of the sample viscosity.When the amount of B_2O_3 increases from 5.24%to 9.24%(mass fraction),the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10^(-6) to10.71×10^(-6) and 10.38×10^(-6) ℃^(-1) respectively.In the case of sealing temperature,its value increases from 453 ℃ to 494 ℃.ZnO-Bi_2O_3-B_2O_3 system low-melting glass powder sintering was with viscous liquid to participate,which could make the densification of glass sample more effective and more efficient.With the content of B_2O_3 increasing,the wetting angle between the glasses samples and stainless steel could also increase,and the resulting appropriate sealing temperature range is 460-490 ℃.

Matched glass-to-Kovar seals in N_2 and Ar atmospheres

The oxidation of Kovar alloy was investigated, the wetting and spreading behavior of hard and soft glasses on Kovar alloy were studed by using the sessile drop method, and the quality and the seal strength of glass-Kovar seals were tested. The experimental results indicated that the preoxidation of Kovar alloy for approximately 10 min at 700℃ in air resulted in excellent adherence in glass-Kovar seals. The wetting and spreading behavior of glass on preoxidized Kovar alloy were superior to that on nonoxidized Kovar alloy. The wetting ability of ASF110 glass, at 950℃ and 980℃ in Ar and N2 atmospheres, was significantly superior to that of ASF200R and ASF700 glasses. The seal quality of the glass-preoxidized Kovar seal was superior to that of the glass-nonoxidized Kovar seal. The shear strength of the ASFll0 glass-preoxidized Kovar seal, which was prepared at 980℃ for 20 min in an Ar atmosphere, was approximately 3.9 MPa.

Preparation,crystallization,and wetting of ZnO-Al_2O_3-B_2O_3-SiO_2 glass-ceramics for sealing to Kovar

A novel type of ZnO-Al2O3-B2O3-SiO2 glass-ceramics sealing to Kovar in electronic packaging was developed, whose thermal expansion coefficient and electrical resistance are 5.2× 10^-6/℃ and over 1×10^13 Ω·cm, respectively. The major crystalline phases in the glass-ceramic seals were ZnAl2O4, ZnB2O4, and NaSiAl2O4. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of alkali metal ions into crystal lattices. It was found that crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner, which made the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature had great effect on the wetting angle. Strong interracial bonding was obtained, which was mainly attributed to the interracial reaction between SiO2 and FeO or Fe3O4.

EFFECT OF SILANE ON THE SURFACE OF SEALING GLASS

This paper, through XPS and IR analyses on the surface of sealing glass, identifies that the surface treatment of sealing glass by silane is a chemical process. On the basis of the analyses, the authors suggest an ideal chemical bonding status between silane and glass surface.

STUDY OF SELENIUM CADMIUM RUBY IRON-SEALING GLASSES

Taking R2-RO-BiOSiO2 system glasses as base,cadmi-um sulfide(CdS) and selenium (Se) powders as colorants, the author has succeeded in producing ruby selenium-cadmium iron-sealing glass-es with suitable coefficient of thermal expansion and other relevant properties necessary for iron-seeling.

铋酸盐封接玻璃的研究及其连接应用现状

无铅低温封接玻璃由于具有绿色安全、成本低、封接温度低等优势,被广泛应用于航空航天、电真空、集成电路等领域。在磷酸盐、钒酸盐、硼酸盐和铋酸盐等多种封接玻璃体系中,因铋与铅具有相似的性质特点,使得铋酸盐玻璃成为最有可能替代铅酸盐玻璃的绿色玻璃钎料。综述了铋酸盐玻璃的成分和性能调控、网络结构的研究现状,介绍了目前使用铋酸盐封接玻璃进行金属、陶瓷同质/异质材料连接的研究进展,最后对未来的发展趋势进行了展望。

m(ZnO)/m(B_(2)O_(3))质量比对低熔点封接玻璃Bi_(2)O_(3)-B_(2)O_(3)-ZnO结构、性能与润湿性的影响

针对真空玻璃封接的性能要求,本文采用高温熔融法制备了一种针对真空玻璃封接的铋系非晶无铅玻璃粉,通过高温X射线衍射、粉末X射线衍射、拉曼光谱、差式扫描量热仪、热膨胀测试和扫描电子显微镜等测试方法,研究了m(ZnO)/m(B_(2)O_(3))质量比对Bi_(2)O_(3)-B_(2)O_(3)-ZnO玻璃的网络结构、特征温度、热膨胀系数和封接温度的影响。结果表明,增加m(ZnO)/m(B_(2)O_(3))质量比可促进锌氧多面体由[ZnO_(4)]向[ZnO_(6)]转变,导致热膨胀系数降低,特征温度升高。当m(Bi_(2)O_(3))∶m(B_(2)O_(3))∶m(ZnO)质量比为80∶7∶13,玻璃具有较低的玻璃化转变温度T_(g)(371℃)和膨胀软化温度T_(f)(401℃),热膨胀系数为9.3×10^(-6)℃^(-1),封接温度为450℃,可满足真空玻璃封接对低熔点封接玻璃粉的要求。

真空玻璃封接用旋转式激光加工装备的设计

激光封边具有封接效率高的优势,但真空玻璃激光封边过程中易发生透射、反射、吸收等相互作用,导致封边质量不佳.针对上述问题,设计了一种包含夹持机构、翻转机构、同步旋转机构的真空玻璃封接用旋转式激光加工装备,并通过对双平行四杆、曲柄摇杆、滑块摇杆的运动分析,优化该装备的翻转机构.实验结果表明,该装备可实现玻璃夹持、翻转、同步旋转等功能,优化后的翻转机构在夹持机构翻转90°时末线速度为0 mm·s^(-1),且翻转过程中线加速度无突变,对支撑柱冲击较小,可稳定夹持平板玻璃,为真空玻璃的封接工艺及制造装备设计提供了参考.

铂薄膜电阻温度传感器玻璃密封材料的稳定性能研究

针对铂薄膜电阻温度传感器中绝缘封装过程中存在的气密、绝缘等性能问题,研究了两种玻璃与铂薄膜温度传感器氧化铝基底间浸润性、气密性、绝缘性及热循环稳定性等性能,优选性能最佳的玻璃密封材料应用在铂薄膜温度传感器中。研究结果表明,热稳定性存在差异SiO_(2)-Ba O-Al_(2)O_(3)-CaO系微晶玻璃与SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系微晶玻璃在800℃~1000℃间与氧化铝基底均具有良好的浸润性。SiO_(2)-Ba O-Al_(2)O_(3)-CaO系玻璃与SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃密封材料在800℃、通气压力在20.7 k Pa下的漏气率分别约为0.0073 sccm·cm^(-1)和0.0065 sccm·cm^(-1),绝缘电阻率分别约为21.6×106Ω·cm和31.1×106Ω·cm。此外,在30℃~800℃热循环500次后,两种玻璃表面出现尺寸不一的孔洞,其中,SiO_(2)-Ba O-Al_(2)O_(3)-CaO玻璃经历500次热循环后孔洞尺寸由0.13μm增至15.62μm,而SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃孔洞尺寸变化较小,表面形貌较为致密。以上研究结果表明,SiO_(2)-B_(2)O_(3)-Al_(2)O_(3)-CaO系玻璃具有更加优异的密封性能、高温绝缘性能及热循环稳定性,更适合用于铂薄膜电阻温度传感器的封装工艺。

可伐合金预氧化工艺对金属-玻璃封接气密性的影响研究

可伐合金和硅硼玻璃是通过可伐合金表面的氧化物与玻璃互溶而紧密结合在一起的,因此可伐合金的预氧化工艺是金属-玻璃封接的关键工序,是直接影响金属-玻璃封接气密性的重要因素。基于空气预氧化方法分析预氧化温度、时间、曲线等工艺因素对可伐合金在空气中预氧化及封接外壳气密性的影响。结果表明,可伐合金在空气中的氧化层厚度随温度和时间单调增加,在500~550℃空气气氛中氧化15~20 min,可伐合金表面形成0.7~1.6μm厚的氧化层,金属-玻璃封接外壳可获得较高的气密可靠性。

基于金属屑传感器密封性改进设计

金属屑传感器已成为机械设备健康状态监测和故障诊断的重要手段。结构式金属屑传感器具有结构简单、吸附磁性粒子强等优点。然而,受到环境压力和温度变化等因素影响,导致传感器连接器输出端容易出现泄漏现象。本文对传感器这类故障的原因进行了分析,并通过采用玻璃烧结的方法实现了外壳和插针材料的连接,对传感器进行了改进设计。经验证,方案可行,产品性能可靠,能够实现金属屑的监测功能。

一种液晶玻盒封口机构的设计与研究

针对一种液晶玻盒手动封口制程中易造成玻盒位置错位、玻盒液晶二次污染、点胶精准率低、老化时间长和老化良率低的问题,设计了一种全自动液晶玻盒封口机构。介绍了当前人工封口时存在的问题,根据人工封口操作时的工艺制程,使其工艺制程自动化,并且对部分现有制程工艺进行改造升级。结果表明,该自动化液晶玻盒封口机构,不仅使得制程中的产品不良率降低,而且使得制程段人员数量大大减少,提高产品质量的同时整体生产成本也大大降低。

空心玻璃微珠对加成型有机硅灌封胶硫化性能的影响

通过不同方式对空心玻璃微珠填料表面进行处理,检测了填料滤液的pH值和电导率。利用有机硅灌封胶在硫化过程中黏度翻倍时间和失粘时间的变化趋势,研究了不同处理方式得到的空心玻璃微珠对有机硅灌封胶硫化性能的影响。实验结果表明:当硅乙烯基与硅氢物质的量比为1∶1时,加成型有机硅灌封胶硫化时间合适;不同处理方式的空心玻璃微珠滤液的pH值变化不大,但电导率差异明显;空心玻璃微珠的处理方式对有机硅灌封胶硫化性能和存放稳定性的影响差异也较大。其中,经乙烯基三甲氧基硅烷、γ-(2,3-环氧丙氧)丙基三甲氧基硅烷、UM08处理后的微珠,其表面因杂质被有效去除或包裹,对加成型有机硅灌封胶的硫化性能和贮存稳定性影响较小。

核化工玻璃固化桶焊接温度场与热变形分析

为了掌握核化工玻璃固化焊封装置钢桶本体与密封盖之间的焊封焊接过程的温度和结构响应,本文基于ANSYS Workbench开展钢桶焊接温度场与热变形分析,采用高斯热源模型模拟焊接热源输入。数值计算结果较好的反映了钢桶本体与密封盖之间进行焊接时的温度变化特征、热应力分布特征和热变形情况,对比了焊封装置钢桶焊接初始温度25℃(常温)与初始温度200℃下热应力与热变形的差异情况,计算分析可为核化工玻璃固化焊封装置钢桶焊接工艺的固化提供参考依据。

Effect of SrO Content on Structure,Thermal Properties and Chemical Stability of Bi2O3-B2O3-ZnO-SrO Low-melting Glass for Si-Al Alloy Package

The 40Bi2O3-30B2O3-(30-x)ZnO-xSrO (x=0-15mol%,BBZSr) glass system was prepared by the conventional melt quenching method.The effect of SrO addition on structure,thermal properties,chemical stability and sealing performance of BBZSr glass were investigated thoroughly.The experimental results show that the total proportions of [BO3] group and [BO4] group decrease and the vibrations of [BiO3] group and [BiO6] group become weaker with the increase of SrO addition content,suggesting the glass network structure is strengthened owing to the SrO addition.Hence,both the thermal and chemical stability were significantly improved as the SrO content was increased.When the SrO content increased from 0 to 15mol%,the glass transition temperature and softening temperature slightly increased from 380 to 388 ℃ and from 392.7 to 402.2 ℃,respectively,meanwhile the coefficient of thermal expansion also increased from 10.49×10^-6 to 11.16×10^-6/℃ (30-300 ℃).The BBZSr glass with 15mol% SrO exhibited excellent comprehensive properties with low glass transition temperature(384.9 ℃),low softening temperature(400.3 ℃),high coefficient of thermal expansion (11.14×10^-6 ℃,30-300 ℃),good thermal and chemical stability.Besides,the glass had the good wetting behavior and sealing performance for Al-50%Si alloy.

Structure of V_2O_5-P_2O_5-Sb_2O_3-Bi_2O_3 glass

The structure ofV2O5-P2O5-Sb2O3-Bi2O3glass and its state of crystallization were studied by means of infrared spectroscopy and X-ray diffraction analysis. The results indicate that, in this glass, V and P exist mainly in the form of a single-stranded linear （VO3）n and an isolated （PO4） tetrahedral with no double bond. Partial V and P are connected through O, forming an amorphous structure of layered vana- dium phosphate. Trivalent Sb3＋ and Bi3＋ open the V=O bond and appear in interlayers, so a weak three-dimensional structure is connected successfully. Along with the substitution of Sb203 for partial V205 or that of P205 for partial V205, the network structure of the glass is rein- forced, and the crystallization is reduced.

Effects of Zn/P ratio on structures and properties of zinc-iron phosphate glasses

Effects of Zn/P ratio on the structures and properties of glasses with the general composition of (80-x)ZnO-20Fe2O3 -xP2O5 (x=40, 45, 50, 55,60) (molar fraction, %) were investigated. Glass structure was measured by infrared absorption spectrum. Glass density (ρ) was measured by the Archimedes method. Coefficients of thermal expansion (α) and characterization temperature were obtained by a dilatometer. Water durability of each glass was estimated from the dissolution rate(DR )in water at 90 C for 24 h. With increasing Zn/P ratio, water durability of zinc-iron phosphate glasses increases dramatically without large increase in the characterization temperature. (80-x)ZnO-20Fe2O3 -xP2O5 glasses with 0.3≤Zn/P≤0.5 are suit for low-to-mid temperature sealing application for substrates with α<8.0×10-6C-1 .

基于响应面法优化航天电连接器的封接工艺研究

以电子玻璃为密封材料的航天电连接器在航空航天领域中得到了广泛应用。本文以电子玻璃密封航天电连接器的气密性为优化目标,对电连接器的封接工艺进行优化。以电连接器的漏率为响应目标函数,运用Box-Behnken试验与响应面分析,对封接工艺条件进行评价。建立二次多项式回归方程模型,对回归方程进行方差分析与系统性检验,并对封接温度、保温时间和氮气流量等工艺参数进行优化。结果表明,最佳封接工艺条件为升温速率10℃/min、封接温度944℃、保温时间32 min、氮气流量1408 L/h、降温速率10℃/min,该条件下航天电连接器的平均漏率为4.07×10^(-10)Pa·m^(3)·s^(-1),与回归模型预测值相符。玻璃与金属封接的机理为玻璃与金属的化学键合与物理啮合,以及玻璃与金属氧化物的良好润湿。