A card edge connector with a seal member that blocks migration of vaporized flux into the connector. The connector includes conductive elements curved at locations and a housing to hold the conductive elements. The housing has openings on a board facing surface. The openings are sized to allow conductive elements inserted into the housing through the openings. Vaporized flux entering the connector through the openings during board assembly may accumulate on contact surfaces of the conductive elements and cause failures to read a card inserted in the connector. The seal member may be attached to the board facing surface of the housing.