【作者】 张凤梅；

【导师】 刘炳泗；

【作者基本信息】 天津大学 ， 物理化学， 2009， 硕士

【摘要】 随着电子信息技术的迅猛发展，电子元件的微型化、集成化及高可靠性已经成为信息产业的主要趋势。因此，正温度系数钛酸钡基陶瓷热敏电阻元件的趋势则是小型化、片式化、低阻化和高可靠性。陶瓷基PTC材料作为电子元件，需要在其表面敷设一层金属。制备半导体欧姆接触电极的方法有很多，如烧渗银、化学镀镍、烧渗Al-Ag浆等。迄今为止，上述所提到的方法制备的陶瓷热敏电阻成本高，经济效益低。然而，一种新的局部表面化学镀铜法应用于钛酸钡基片式材料表面进行铜镀层的沉积，可进一步降低成本，并提高电子元件性能。镀层的性能研究结果表明：镀层与陶瓷基体之间有着良好的结合力，电极的电阻、抗拉力、耐电压性能、耐湿性能和焊接性能均满足工业生产的要求。同时利用X-射线衍射技术（XRD）对未涂覆浆料的陶瓷基体表面和制成的陶瓷热敏电阻元件的结构进行了表征。利用原子力显微镜（AFM）对电极制备过程中的表面形貌进行了研究。我们所发明的工艺用来制备的欧姆接触电阻的生产成本仅为按传统工艺流程所制备的电极的成本的25%。在电子元件制备领域，用该方法生产电阻也已经得到了大力的商业化推广。本文中,还提出了切实可行的测定镀液中甲醛和铜的分析方法。更多还原

【Abstract】 With the rapid development of electronic information technology, theminiaturization, integration and high reliability of electronic components havebecome the main trend of the electronic information industry. Consequently,miniaturization, chip type,low-resistance and high reliability are becoming the maintendency of the BaTiO3-based positive temperature coefficient resistance(PTCR). Aselectronic components, the surface of ceramic-based thermistors have to be coatedwith a layer of metal. There are many ways of forming a ceramic-based electrode,including silver-layer coating, electroless Ni-plating and Al/Ag pastes coating. So far,the methods we mentioned above in the specifications are high for ceramic thermistorproduction. However, a new method of fabrication - a Cu-layer on the surfaces ofBaTiO3-based chip resistor is put forward in this paper, which is called the regionalelectroless Cu-plating. Furthermore, the performance of the coatings wereinvestigated. The major findings are: adhesion force between electrode and thesubstance, resistance, tensile resistance, the voltage-withstanding, moisture-resistance,solderability, and so forth, all meet the demands of the industry. Both thecharacterstics of the substrate surface without coated with pastes and that of thesubstrate with Cu-plating are studied by means of X-ray Diffraction. Also the processof forming an electrode is tested by means of Atomic Force Microscope(AFM). Theproduction cost of the technology we invented and used for the preparation of ohmiccontact resistance is merely 25% of that produced in a traditional way. In the field ofpreparation of electronic components, this method of fabrication composite electrodeon the surface of the ceramics bulk has been widely applied in the production ofPTCR thermistors.Also, practical methods were proposed in this paper to detect the concentrationof formaldehyde and copper ion of the bath.更多还原