| 摘要 |
PROBLEM TO BE SOLVED: To provide a board wherein mechanical strength is excellent, thermal expansion coefficient is low, dimensional stability and through hole reliability are excellent, relative permittivity is extremely low at 2.1 at most, and application to a communication apparatus using radio wave of millimeter wave band is sufficiently enabled. SOLUTION: In a printed circuit board 1, a prescribed circuit pattern 3 is formed by using copper foil on at least a single side of a sheet-shaped insulating layer 2 wherein silica fine hollow members are compounded in fluororesin at a rate of 10-70 vol.%. The printed circuit board is constituted by using the silica fine hollow member wherein the volume ratio of silica part and air in a hollow part is set as 1:6-1:3. |
