Board material
A board material A board material having a flexible sheet member, and a plurality of hard strip members including a plurality of first hard strip members bonded in parallel to a first side of the flexible sheet member and second hard strip members arranged into sets and bonded in parallel to a second side of the flexible sheet members corresponding to the first hard strip members, the first hard strip members having a width in an integral multiple of the width of the second hard strip members.
Y B Y B
Y10T B32B Y10T B32B
additional inventional additional inventional
Wen-Tsan
Wang