Structure for joining a wire to a solid electrolytic element

A structure for attaching a wire to a solid electrolytic element with solder, comprising:

• a solid electrolytic element;
• an intermediate layer formed on a surface of the solid electrolytic element;
• terminal means attached to the intermediate layer for attaching a wire to the solid electrolytic element, said terminal means comprising a base layer and an upper layer, wherein the base layer is adjacent to the intermediate layer and contains a larger amount of the composition of the intermediate layer than the upper layer which is not adjacent to the intermediate layer, said terminal means comprising a plurality of terminals, wherein at least one of said plurality of terminals is electrically connected to a plurality of electrode portions formed on a surface of the solid electrolytic element, said plurality of electrode portions including first and second measuring electrode portions;
• means for heating said solid electrolytic element, wherein said terminal means includes two heating terminals electrically connected to said heating means;
• and
• an outer insulating layer positioned over said heating means such that said two heating terminals are not overlapped by said outer insulating layer, said outer insulating layer having a plurality of windows positioned over said first and second measuring electrode portions such that said first and second measuring electrode portions are not overlapped by said outer insulating layer;
• wherein said base layer of said terminal means includes 20% to 60% of the same material as that of which said intermediate layer is composed, and said upper layer of said terminal means includes less than 10% of the same material as that of which said intermediate layer is composed;
• wherein the intermediate layer has a thermal conductivity coefficient larger than the thermal conductivity coefficient of the solid electrolytic element so that heat is uniformly conducted to said terminal means and said intermediate layer, thereby to ensure the fluidity of said solder, and a thermal expansion coefficient not greater than the thermal expansion coefficient of the solid electrolytic element so that said intermediate layer has dimensions which do not deviate from those of said solid electrolytic element and is prevented from detaching from said solid electrolytic layer due to thermal expansion thereof.