Board to board connector assembly having improved terminal arrangement

A hermaphroditic board to board connector comprising:

• an insulative housing defining a pair of side walls opposite to each other in a transverse direction while each extending along a longitudinal direction perpendicular to said transverse direction;
• a slot defined between said pair of side walls along said longitudinal direction and exposed to an exterior in a vertical direction perpendicular to both said transverse direction and said longitudinal direction;
• a plurality of disposed in the housing along said slot, each of said passageways spanning in the transverse direction;
• a plurality of contacts disposed in the corresponding passageways, respectively, each of said contacts extending from one side wall to the other and unitarily defining in sequence a surface mounting tail section essentially extending outwardly around a bottom face of the housing under said one side wall in the transverse direction, a first compressible portion forming a first downward opening and having a retention section upwardly extending from the tail section and intimately confronting an inner surface of said side wall and securing to the housing, a second compressible portion forming a second downward opening and connected to the first compressible portion via a connecting portion around said bottom face of the housing;
• wherein
• the housing and the contacts are configured to allow the contacts to be assembled into the corresponding passageways upwardly from the bottom face of the housing, and each of said contacts defines a first contacting point on the first compressible portion, and a second contacting point and a third contacting point both on the second compressible portion for mating with another identical connector.