METHOD OF PRODUCING AREAS OF RELATIVELY HIGH ELECT

专利名称：METHOD OF PRODUCING AREAS OF

RELATIVELY HIGH ELECTRICAL RESISTIVITYIN DIELECTRIC SUBSTRATES

发明人：PURDES A,US申请号：US3754987D申请日：19710604公开号：US3754987A公开日：19730828

摘要：Areas of relatively high electrical resistivity in a dielectric substrate, such asdoped barium titanate, may be produced by first forming a relatively porous substratewhich may be handled without breaking, as by prefiring the substrate, masking selectedportions of the substrate with a material such as a photoresist material which willvaporize during final firing of the substrate, contacting the substrate with a solution of afirst reactant, immersing at least a portion of the substrate in a solution of a secondreactant which will react with the first reactant to precipitate in situ in a portion of thesubstrate a transition metallic compound which is insoluble in the solutions and which isadapted to increase the electrical resistivity of the said portion of the substrate, andthereafter firing the sustrate at a temperature on the order of 1,300 DEG - 1,450 DEG C.to reduce the porosity of the substrate and to incorporate the insoluble compound intothe lattice of selected portions of the substrate. The starting material may be a

lanthanum doped barium titanate, for example, the solution of the first reactant may bean aqueous solution of a compound such as ammonium hydroxide, and the solution ofthe second reactant may be an aqueous solution of an iron compound such as ferric

chloride which reacts with the ammonium hydroxide to precipitate in situ ferric hydroxidewhich, when fired, produces a high resistivity area.

申请人：TEXAS INSTRUMENTS INC,US

更多信息请下载全文后查看