【作者】 王秀宇；

【导师】 张之圣；

【作者基本信息】 天津大学 ， 微电子学与固体电子学， 2007， 博士

【摘要】 电阻器是电子设备中常用的电子元器件之一,在某些特殊环境下,要求电阻器能耐高温和高湿,且电阻变化率很小,而电阻器用的封装涂料在制备符合性能要求的电阻器方面起着至关重要的作用。在电子封装中,酚醛树脂和环氧树脂具有优异的电气性能,是常用的电子封装材料。酚醛树脂固化体系简单(苯酚和甲醛聚合),是电阻器用涂料的首选材料,当前国内电阻器生产公司主要使用国产或进口的酚醛树脂涂料。但酚醛树脂存在一些难以克服的缺点,高温固化时会释放出有毒物质苯酚和甲醛,并在涂层膜中产生针孔。酚醛涂料固化物质脆、韧性差,难以满足特殊环境下的耐高温、耐高湿性能要求。为从根本上解决酚醛树脂涂料的固有缺点,本文另辟蹊径,用端羟基硅油、环氧树脂、酸酐、二元醇、纳米SiO2等首次研制出适合自动化生产线需要的精密金属膜电阻器用耐高温、耐高湿环氧树脂涂料。用具有活性的端羟基硅油改性环氧树脂,制得韧性较好的有机硅环氧树脂,解决了环氧树脂固化物交联密度高时韧性差的缺点。用酸酐高温固化剂、二元醇促进剂组成的潜伏性固化体系创造性地解决了电阻器用环氧树脂涂料的固化问题,从而把涂料室温使用期长(至少保质6个月)和高温快速固化(170℃时2min内表干)的矛盾统一起来。这种体系的涂料具有较好的耐高温、高湿性能,在耐高温实验中,电阻变化率在万分之五左右,满足指标ΔR/R≤1.0‰要求;耐高湿实验中,电阻变化率最小可达1.05‰,接近指标ΔR/R≤1.0‰。电解氧化腐蚀使电阻器金属膜局部或全部破坏是电阻器耐湿失效的原因。纳米SiO2具有较高的表面活性和三维对称结构,与环氧树脂有着较强的作用力。电阻涂料研究表明,纳米SiO2对环氧树脂涂料的固化具有催化作用,提高表干效果,并使涂料固化物具有较好的防水性能,满足耐高湿实验中电阻变化率小于1.0‰的要求。低-高温固化工艺能提高环氧树脂固化物的性能,140℃/3min-170℃/4min、140℃/3min-170℃/2min-190℃/2min等表干工艺首次应用于提高电阻涂料的耐高湿性能,取得较好的效果。249K?临界阻值电阻器在250V极限电压下实验以及2.2M?电阻器的金属膜薄,对涂料耐高湿性能要求很高;双固化剂/双促剂体系涂料的设计创造性地解决了这两种特殊电阻器的耐高湿问题,耐高湿实验后电阻变化率满足特定性能指标要求。通过与日本和国产的酚醛电阻涂料比较,所研发的环氧树脂电阻涂料具有优异的耐高湿性能,并避免了使用酚醛涂料所带来的缺点。目前,所研制涂料已通过生产线试验,正在北京公司进行240h和2000h的耐高湿、耐高温环境模拟试验。更多还原

【Abstract】 Resistor is one of components commonly used in electronic equipments. In some special use, the resistor is required to resist high temperature and humidity and the varying ratio of resistance is very little. While the packaging paint used for resistors plays a critical role in the produce of resistors meeting performance required.Phenolic resin and epoxy resin is in common use in electronic packaging because of their excellent electrical properties. With simple curing system, just polymerizing of phenol and formaldehyde, phenolic resin becomes preferred material of paint for resistor. Resistor companies in our country mainly use phenolic resin paint made in our own country or imported at present. However, phenolic resin paint has some avoidless disadvantages, with toxicants released such as phenol and formaldehyde leading to pinholes in finished film when cured at high temperature. And the polymer of phenolic resin paint for resistor has bad tenacity, incapable of meeting requirements of high temperature and humidity resistance in special circumstances. In order to radically solve the intrinsic disadvantages of phenolic resin paint, a kind of paint in the paper, with properties of high temperature and humidity resistance and suitable for automated production line for mental film resistors, was first developed in a larruping way by hydroxy end capping silicone oil, epoxy resin, acid anhydride, diols, nano-SiO2 and so on.Activated hydroxy end capping silicone oil was used for modifying epoxy resin to prepare organic silicone epoxy resin with better tenacity, which solved the disadvantage of bad tenacity of epoxy resin polymer with high crosslink density. Latent curing system, composed of acid anhydride high temperature curing agent and diols accelerant, creatively solves the curing problem of epoxy resin paint for resistor, and combines long use at room temperature, with good property kept for at least six months, to fast curing in 2min at 170℃. Such paint has good property of high temperature and humidity resistance. The varying ratio of resistance is about 0.5‰, meeting indicator requirementΔR/R≤1.0‰, in high temperature resistance experiment. The least varying ratio of resistance is about 1.05‰, close to indicator requirementΔR/R≤1.0‰, in high humidity resistance experiment. The failure of high humidity resistance for resistor is attributed to part or complete damage of metal film on resistor by electrolytic oxidation corrosion. Nano-SiO2, with higher surface activity and tridimensional symmetrical structure, has a strong force with epoxy resin. Investigation on paint for resistor shows nano-SiO2 can catalyze the curing of epoxy resin paint, improve surface dry effect, make the paint polymer has good waterproof property and meet the indicator requirementΔR/R≤1.0‰in high humidity resistance experiment.Low-high-temperature curing process can improve the properties of epoxy resin polymer. Surface dry processes, such as 140℃/3min-170℃/4minn and 140℃/3min-170℃/2min-190℃/2min and so on, are first used to improve the property of high humidity resistance of resistor paint and achieve better results. Critical resistance 249K? resistor, experimenting using 250V limit voltage, and 2.2M? high resistance resistor with thinner film have more rigorous requirement of high humidity resistance of resistor paint. The design of epoxy resin paint for resistor, with two curing agents and dual accelerants system, creatively resolves the problem of high humidity resistance for the two particular kinds of resistors, the varying ratio of resistance meeting indicator requirement given in high humidity resistance experiment. Compared with phenolic resin paint made in our own country and imported from Japan, the epoxy resin paint developed by us has excellent property of high humidity resistance, and avoids the disadvantages resulted from the application of phenolic resin paint. Currently, the epoxy resin paint developed has passed experiment on the production line of resistor and having experimented on high humidity and temperature surroundings simulated resistance of paint for 240h and 2000h in Bejing company.更多还原