水基流延成型制备片式电感器件研究

以聚丙烯酸铵为粉体分散剂,聚乙烯醇和丙烯酸乳液为复合粘结剂,聚乙二醇(PEG600)为增塑剂,制备了Ni-Zn水基流延成型铁氧体浆料。研究了Ni-Zn铁氧体粉体在水中的稳定性,以及粘结剂含量、固相含量对浆料性能、流延薄带性能及薄带压合性能的影响。结果表明:在pH=9.5、分散剂含量(质量分数)为6‰时,Ni-Zn铁氧体粉体在水中具有较好的稳定性;在聚乙烯醇、丙烯酸树脂和固相含量(质量分数)分别达到6.5%、15%和54.5%时,所制Ni-Zn浆料具有较好的流动性,以其制成的20μm薄带则结构致密、附着力及压合较好、无分层;以水性浆料和有机浆料分别制成的1005型号电感(介质膜厚和线圈匝数相同)在100 MHz下测得的阻抗几乎相同,而前者成本却降低了80%左右。

Study on the aqueous tape casting preparation of chip inductors

Ni-Zn ferrite slurry for aqueous tape-casting was prepared with ammonium polyacrylate as the dispersant,polyvinyl alcohol and acrylic emulsion as the composite binder,and polyethylene glycol(PEG600) as the plasticizer.The stability of Ni-Zn ferrite powder in aqueous solution was studied through measuring the Zeta potential and sediment height of the solution.The effects of binder content and solid content on the properties of the Ni-Zn slurry and the tape-casting film as well as the heat-press behavior of the films were investigated.The results indicate that the Ni-Zn ferrite slurry is stable when the dispersant content(mass fraction) and pH are 0.6% and 9.5 respectively,and shows good flowability when the polyvinyl alcohol,acrylic emulsion and solid contents(mass fraction) are 6.5%,15% and 54.5% respectively.The film prepared with the above slurry shows a dense structure without bubble,good bonding to substrate and no delamination after heat-press.The impedance values(measured at 100 MHz) of the 1005-type inductors prepared with the aqueous slurry and the organic slurry respectively are almost same,while the cost of the aqueous system is about 80% lower than that of the organic system.