A variety of electric squibs have been developed as squibs for gas generators for inflating air bags equipped in cars and squibs for micro gas-generators used for seat belt pretensioners.
Such a squib usually has metal pins for electrically connecting to the external, and a heating element at the other ends of the metal pins for igniting an explosive.
As examples of such a heating element, heating elements incorporated in a printed sub-circuit have been known as disclosed in a patent document 1 and a patent document 2 corresponding to the patent document 1.
On the other hand, moreover, it has been contemplated to link an air bag system to a local area network (LAN) to control ignition of a squib by communication.
In this case, it is necessary to locate electric circuits in the squib for the communication and ignition as described in a patent document 3.
With the squib constructed as described above, therefore, it becomes necessary to provide means for causing electric current to flow through the electric circuits built in the squib.
In a patent document 4, for example, disclosed is a structure of an electric circuit board fixed to electrode pins of a closure plug by soldering or the like.
In the method disclosed in the patent document 4, after the circuits have been previously constructed on a board and connected to electrode pins of a closure plug, a resin must be molded around the circuits and the board.
However, particularly the resin molding produced under a condition already connected to a closure plug is seriously lower in productivity as compared with the molding of parts such as a usual IC fixed to a lead frame.
Moreover, in the case that connection between the electrode pins and the electric circuits is firmly fixed by soldering, there would be a risk of solder cracks due to residual stresses.    Patent document 1: Specification of French Patent Application Laid Open No. 2,704,944    Patent document 2: Specification of U.S. Pat. No. 5,544,585    Patent document 3: Official Gazette of Japanese Patent No. 3,294,582    Patent document 4: Specification of European Patent Application Laid Open No. 1,256,775