To provide solderable surface of electronic components electrically connectable with high reliability, flexible and selectively electrical conductive by plating the selected region which z-axially penetrates through a continuous porous material having x-axis, y axis and z axis with an electrical conductive metal, and terminating this electrical conductive channel with a solder plated region on the opposite surfaces of the porous material.
Oriented and expanded polytetrafluoroethylene, for example, which has a fine structure of nodes mutually connected by fibrils and approximately 20-90% of space volume, is used as a material. At the same time a porous material which ultraviolet rays can pass through to form a z-axis electrical conductive channel is used. After it has been treated so as to have z-axial conductive channel which has an irregular shape and is selectively conductive, a soldering region is provided and formed into a flexible and selectively electrical conductive composite material 24, then arranged on the upper surface of a circuit element 23. A chip 21 is matched with the circuit element 23, provided with pressure, and after it is heated and cooled, metallic connection is provided between the chip 21 and the circuit element 23.
JOHNSON DANIEL D (US)
BANKS DONALD R (US)
AMEEN JOSEPH G (US)
