Method for manufacturing large ceramic co-fired articles

Abstract

A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of: —a) forming ( 34 ) a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact; b) disposing ( 38 ) a conductor or conductor precursor to at least one surface of at least one of the plurality of green compacts to form at least one patterned green compact; c) assembling the at least one patterned green compact with one or more of the plurality of green compacts or patterned green compacts or both to form a laminated assembly; d) isostatically ( 40 ) pressing the laminated assembly to form a pressed laminated assembly; e) firing ( 42 ) the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together.

1 . A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of:—
 a) forming a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact; 
 b) disposing a conductor or conductor precursor to at least one surface of at least one of the plurality of green compacts to form at least one patterned green compact; 
 c) assembling the at least one patterned green compact with one or more of the plurality of green compacts or patterned green compacts or both to form a laminated assembly; 
 d) isostatically pressing the laminated assembly to form a pressed laminated assembly; 
 e) firing the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together. 
 
     
     
         2 . The method as claimed in  claim 1 , wherein step (b) comprises the step of applying a metallization layer to at least one surface of at least one of the plurality of green compacts to form the at least one patterned green compact. 
     
     
         3 . The method as claimed in  claim 1 , in which:—
 step c) further comprises positioning one or more shapes formed from a fugitive material between at least two of the green compacts, whether either or both is patterned or not; 
 subsequent to step d) the fugitive material is removed to leave hollow channels within the article. 
 
     
     
         4 . A method of forming one or more high temperature co-fired ceramic articles, comprising the steps of:—
 a) forming a plurality of green compacts, by a process comprising dry pressing a powder comprising ceramic and organic binder to form a green compact; 
 b) assembling the at least one patterned green compact with one or more shapes formed from a fugitive material disposed between at least two of the green compacts to form a laminated assembly; 
 c) isostatically pressing the laminated assembly to form a pressed laminated assembly; 
 d) firing the pressed laminated assembly at a temperature sufficient to sinter the ceramic layers together 
 subsequent to step d) removing the fugitive material to leave hollow channels within the article. 
 
     
     
         5 . The method as claimed in  claim 1 , in which the articles have at least one orthogonal X and Y dimension greater than 200 mm and an orthogonal dimension Z less than the X and Y dimensions. 
     
     
         6 . The method as claimed in  claim 1 , in which both orthogonal X and Y dimension are greater than 200 mm. 
     
     
         7 . The method as claimed in  claim 1 , in which the articles have an orthogonal dimension Z less than 10% of the longer of the X and Y dimension. 
     
     
         8 . The method as claimed in  claim 1 , in which the articles have an orthogonal dimension Z less than 10% of the shorter of the X and Y dimension. 
     
     
         9 . The method as claimed in  claim 1 , which the powder further comprises a plasticizer. 
     
     
         10 . The method as claimed in  claim 1 , in which the powder further comprises a dispersant. 
     
     
         11 . The method as claimed in  claim 1 , in which the powder is a spray dried powder. 
     
     
         12 . The method as claimed in  claim 1 , further comprises the step of assembling a second insulative ceramic material with the one or more of the plurality of green compacts or patterned green compacts or both such that the laminated assembly comprises one or more of the plurality of green compacts or patterned green compacts or both with the second insulative ceramic material. 
     
     
         13 . The method as claimed in  claim 12 , wherein the second insulative material is a tape cast material or a green compact. 
     
     
         14 . The method as claimed in  claim 12 , in which the second insulative material forms an outermost layer of the laminated assembly. 
     
     
         15 . The method as claimed in  claim 12 , in which the second insulative material has a thickness less than half that of any one of the plurality of green compacts or patterned green compacts. 
     
     
         16 . The method as claimed in  claim 1 , in which the metallization is less than 50 μm thick. 
     
     
         17 . The method as claimed in  claim 1 , in which the orthogonal X and Y dimensions are both 300 mm or more. 
     
     
         18 . The method as claimed in  claim 17 , in which both orthogonal X and Y dimensions are both 450 mm or more. 
     
     
         19 . The method as claimed in  claim 1 , in which the one or more high temperature co-fired ceramic articles are heaters. 
     
     
         20 . The method as claimed in  claim 1 , in which the high temperature co-fired ceramic article is an electrostatic chuck comprising;
 an insulating base;   a one or more electrically conductive electrodes disposed on said insulating base; and   a dielectric top layer, having a top surface and an opposite bottom surface, such that said electrodes are disposed between said insulating base and said dielectric top layer.   
     
     
         21 . The method as claimed in  claim 12 , wherein the one or more of the plurality of green compacts or patterned green compacts defines the insulating base and the second insulative ceramic material defines the dielectric layer. 
     
     
         22 . The method as claimed in  claim 20 , further comprising the step of machining the high temperature co-fired article such that the dielectric layer has a thickness of substantially less than 1 mm or less than 0.5 mm or less than 0.25 mm, or less than 0.1 mm. 
     
     
         23 . A high temperature co-fired ceramic article formed by the method of  claim 1 . 
     
     
         24 . A high temperature co-fired ceramic article have at least one orthogonal X and Y dimension greater than 200 mm and an orthogonal dimension Z less than the X and Y dimensions, the high temperature co-fired ceramic article comprising a continuous unperforated metal conductor embedded therein. 
     
     
         25 . A high temperature co-fired ceramic article as claimed in  claim 24 , in which at least one orthogonal X and Y dimension is 300 mm or more. 
     
     
         26 . An electrostatic chuck, comprising:
 an insulating base;   one or more electrically conductive electrodes disposed on said insulating base;   a dielectric top layer, having a top surface and an opposite bottom surface, such that said electrodes are disposed between said insulating base and said dielectric top layer; wherein the electrostatic chuck have at least one orthogonal X and Y dimension greater than 200 mm and an orthogonal dimension Z less than the X and Y dimensions.   
     
     
         27 . The electrostatic chuck as claimed in  claim 26 , in which at least one orthogonal X and Y dimension is 300 mm or more. 
     
     
         28 . The electrostatic chuck as claimed in  claim 26 , in which the insulating based comprises a heater. 
     
     
         29 . The electrostatic chuck as claimed in  claim 28 , in which one or more electrical conductors is/are embedded within the insulating base. 
     
     
         30 . The electrostatic chuck as claimed in  claim 26 , in which the insulating base and/or the dielectric layer is a material selected from the group consisting of alumina, titania, zirconia, and alloys containing any of the foregoing. 
     
     
         31 . The electrostatic chuck as claimed in  claim 26 , in which the one or more electrical electrodes is material selected from the group consisting of platinum, palladium, gold, tungsten, molybdenum, niobium, tantalum, and alloys of any of the foregoing. 
     
     
         32 . The electrostatic chuck as claimed in  claim 26 , in which the electrostatic chuck is a co-fired monolithic ceramic-and-metal composite. 
     
     
         33 . The electrostatic chuck as claimed in  claim 26 , in which the dielectric layer has a thickness of substantially less than 1 mm or less than 0.5 mm or less than 0.25 mm, or less than 0.1 mm. 
     
     
         34 . A method of flat firing an article comprising the steps of;
 a. supporting the article on an insulting setter having at least one substantially flat surface;   b. mounting an insulating weight having at least one substantially flat surface on the article such that the article lies between the substantially flat surface of the insulating setter and the insulating weight.   
     
     
         35 . The method as claimed in  claim 34 , wherein said at least one surface of the setter and/or weight is/are machined substantially flat. 
     
     
         36 . The method as claimed in  claim 34 , wherein in the setter and/or the weight comprises alumina. 
     
     
         37 . The method as claimed in  claim 34 , wherein the article is a high temperature co-fired ceramic article as defined in any of the  claims 23  to  25 .