(華中科技大學(xué) 電子科學(xué)與技術(shù)系， 武漢 430074)
摘 要: 研究了用注凝成型工藝制備片式PTCR熱敏陶瓷。 采用PMAA-NH4為分散劑， 丙三醇為增塑劑， 并加入適量的有機單體AM制備了高固相含量、 低粘度的BaTiO3半導(dǎo)瓷漿料， 研究了漿料粘度及坯體的性能與漿料固相體積分數(shù)、 有機單體含量及增塑劑含量之間的關(guān)系。 研究表明： 漿料固相體積分數(shù)對坯體的干燥及燒結(jié)行為有較大影響， 當(dāng)漿料固相體積分數(shù)在45%以上時， 可有效避免制品干燥和燒結(jié)過程中收縮過大而產(chǎn)生的變形開裂缺陷； 當(dāng)有機單體的質(zhì)量分數(shù)為2％~4%， 丙三醇的體積分數(shù)為3％~6%時， 可獲得有一定強度和柔韌性的生坯； 研究了注凝成型PTCR陶瓷的微觀結(jié)構(gòu)及陶瓷元件的PTCR性能， 成功地制備了層數(shù)為5、 室溫電阻為0.8 Ω、 電阻溫度系數(shù)為13.40%/℃、 升阻比大于105的多層片式PTCR元件。
關(guān)鍵字: 片式PTCR； 疊層結(jié)構(gòu)； 注凝成型； 固相體積分數(shù)； 粘度
（ Department of Electronic Science and Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract: Gelcasting was used for the fabrication of chip PTCR thermistors. BaTiO3-based ceramic slurries with high solid loading and low viscosity were prepared by using ammonium salt of poly (methacrylic acid) (PMAA-NH4) as a dispersant, glycerol as plasticizer and adding some monomers. The influence of solids loading, content of monomers and plasticizer on the viscosity of slurry and the physical characterization of green sheets was investigated. The results show that increasing the solids loading of slurry up to 45% allows minimizing deformation of green sheets during drying and sintering process effectively. When the content of monomers in shurry is 2%-4%(mass fraction), and the content of plasticizer in shurry is 3%-6%(mass fraction), green sheets with good strength and flexibility are obtained. The microstructures and the electric characteristics of PTCR chip thermistors were investigated. A five-layer chip PTCR thermistor with room resistance of 0.8 Ω, temperature coefficient of resistance of 13.40%/℃, and ratio of maximum to minimum of resistance larger than 105 is successfully fabricated.
Key words: PTCR chip thermistors; multilayered structure; gelcasting; solids loading; viscosity
