Abstract: The ceramic substrate for electronic circuit of the present invention comprises a ceramic layer and a conductive layer which is patterned on the ceramic layer, wherein the conductive layer comprises copper or an alloy containing copper as its main component. The ceramic layer entirely comprises a complex oxide or an oxide solid solution containing copper element and at least one component excluding copper element. Moreover, the ceramic layer is insulated.

Abstract: In an agitating mill for producing the objective fine powder, the agitating medium having an average particle diameter of no more than 0.6 mm is charged in an annular gap between the external side wall of the agitator and the internal side wall of the milling vessel. Thereby the agitator can be rotated at a peripheral speed of no less than 30 m/s, and it results in a high grinding rate and reduced amount of impurity which means worn-out grinding media included in the objective fine powder.

Abstract: A piezoelectric ceramic comprising at least two kinds of ceramic domains that are different from each other either in composition or in piezoelectric characteristics. It is made possible to produce a piezoelectric ceramic with better piezoelectric characteristics than that composed of a single kind of ceramic domain by having the compositions or the piezoelectric characteristics of each ceramic domain properly selected. For example, it is possible to obtain a piezoelectric ceramic of an extremely small rate of change in resonance frequency in response to a change in temperature by having a ceramic domain with a positive rate of change in resonance frequency in response to a change in temperature and the one with a negative rate of change in resonance frequency in response to a change in temperature combined.

Abstract: Provided is a method for milling ceramic powder which comprises wet-milling at least one ceramic powder by a media agitating mill wherein the volume of liquid is 4 times or less the net-volume of the ceramic powder. A dispersing agent is added and milling is carried out using grinding media of 1 mm, or less, in diameter. Further, a media agitating mill used for the above method is provided which comprises a milling chamber, grinding media and an agitator wherein the peripheral speed of the agitator is 10 m/s or more, the grinding media have a diameter of 1 mm or less and packing fraction of the grinding media is 65-85 vol %. A method for making a sintered body from fine powder produced by the above milling method is also disclosed.

Abstract: A thermoelectric semiconductor device having a porous structure and an air-tight sealing structure maintaining it in a deaerated state is disclosed. A refrigeration panel comprising a plurality of p-type and n-type semiconductor elements each having a structure mentioned above, in which the elements are arranged alternatively and electrically connected in series is also disclosed.

Abstract: A method for milling ceramic powder and making a sintered body from the powder produced by such method are disclosed. A preferred embodiment includes wet-milling at least one ceramic powder by a media agitating mill wherein the volume of liquid is not more than 4 times the net-volume of the ceramic powder, a dispersing agent is added and milling is carried out using grinding media of not larger than 1 mm in diameter. A media agitating mill used for the above method is provided which includes a milling chamber, grinding media and an agitator wherein the peripheral speed of the agitator is at least 10 m/s, the grinding media having a diameter of not larger than 1 mm and the packing fraction of the grinding media is 65-85% by volume.

Abstract: A thermoelectric semiconductor device having a porous structure and an air-tight sealing structure maintaining it in a deaerated state is disclosed. A refrigeration panel comprising a plurality of p-type and n-type semiconductor elements each having a structure mentioned above, in which the elements are arranged alternatively and electrically connected in series is also disclosed.