Clad material for lead wire connection

Abstract

An electroacoustic transducer 1 includes a base 24 made of a magnetic material, a magnetic core 22 made of a magnetic material and erected on the base 24 , and a diaphragm 20 made of a magnetic material and supported with a space distanced from the top end of the magnetic core 22 . The base 24 , the magnetic core 22 and the diaphragm 20 form a magnetic circuit. The electroacoustic transducer 1 includes a magnet 25 supplying a static magnetic field, and a coil 23 supplying an oscillation magnetic field to the magnetic circuit. A lead wire 23 a ( 23 b ) of the coil 23 and a connection land 50 a ( 50 b ) are electrically connected by resistance welding or thermal welding with the lead wire 23 a ( 23 b ) held between the connection land 50 a ( 50 b ) and a cover member 52 a ( 52 b ).

What is claimed is:  
     
         1 . A structure of lead wire connection comprising: 
 a lead wire covered with an electrical insulating coating;    a land portion electrically connected to the lead wire; and    a cover member disposed in opposition to the land portion with the lead wire held between the land portion and the cover member;    wherein the cover member and the lead wire are electrically connected by resistance welding; and    the lead wire and the land portion are also electrically connected by resistance welding.    
     
     
         2 . A method of lead wire connection comprising: 
 mounting a lead wire covered with an electrical insulating coating onto an upper surface of a land portion;    supplying a cover member onto the lead wire;    pressing the lead wire via the cover member against the upper surface of the land portion by a first electrode tool having a heater mechanism while supporting a lower surface of the land portion by a second electrode tool;    heating the first electrode tool by the heater mechanism to make the lead wire exposed partially; and    applying an electric current between the first and second electrode tools so that resistance welding is effected between the cover member and the lead wire and between the lead wire and the land portion.    
     
     
         3 . A method of lead wire connection comprising: 
 mounting a lead wire covered with an electrical insulating coating onto an upper surface of a land portion;    supplying a cover member onto the lead wire;    pressing the lead wire via the cover member against the upper surface of the land portion by a pressure welding tool having a heater mechanism; and    heating the pressure welding tool by the heater mechanism to make the lead wire exposed partially, and to supply a melted portion of the cover member around the lead wire and the land portion.    
     
     
         4 . The method of lead wire connection according to  claim 2 , wherein the cover member comprises a laminate of a plurality of metal materials having different melting points; and 
 the metal material brought into contact with the lead wire has a melting point lower than a melting point of the metal material brought into contact with the first electrode tool.    
     
     
         5 . The method of lead wire connection according to  claim 3 , wherein the cover member comprises a laminate of a plurality of metal materials having different melting points; and 
 the metal material brought into contact with the lead wire has a melting point lower than a melting point of the metal material brought into contact with the pressure welding tool.    
     
     
         6 . A clad material for lead wire connection comprising: 
 a laminate of a plurality of metal materials having different melting points,    wherein the clad material is disposed between a lead wire and a welding tool when the lead wire and a land portion are connected by resistance welding or thermal welding.