Abstract: A circuit board comprising a board body which includes an insulating substrate or a plurality of laminated insulating substrates. The circuit board includes a connection material for electrically connecting together circuit patterns that are formed on both surfaces of the board body and/or a connection material for electrically connecting together a circuit pattern formed on one surface of the board body and circuit patterns formed between the insulating substrates. The connection material is constituted by an electrically conducting substance filled in a through-hole formed in the board body, and at least one end surface of the electrically conducting substance is substantially flush with the circuit pattern formed on one surface of the board body.

Abstract: A curable electroconductive composition which comprises (1)(a) a monoglycidyl compound such as cardanolglycidyl ether having 18 to 30 carbon atoms and further having in a molecule thereof an epoxy group, one or more aromatic hydrocarbon groups and an aliphatic hydrocarbon group having 6 to 20 carbon atoms and (b) a crosslinking component such as bisphenol A diglycidyl ether having in a molecule thereof two or more epoxy groups and one or more aromatic hydrocarbon groups, (2) a curing agent, and (3) a copper powder. The curable electroconductive composition does not develop cracks during the curing even when thick electrically conducting cured products are formed such as electrically conducting through-holes in printed wiring board, and the cured product thereof exhibits stable electrically conducting property over extended periods of time.