High-density, high-pin-count flexible SMD connector for high-speed data bus

This paper describes a high-density, high-pin-count flexible SMD connector used for high-speed data buses between MCMs or daughter boards. This connector consists of a flexible film cable interconnection with accurately controlled characteristic impedance, and a contact housing composed of double-line contacts and SMD type leads. It has 98 contacts each with a pitch of 0.4 mm. The connector mounting area is 6 mm wide and 23 mm long. The flexible cable has a double-sided triple-parallel micro stripline structure with an insertion force of less than 2.9 kgf and characteristic impedance of 48 to 50 Ω. Insertion loss is -0.5 dB at 600 MHz and crosstalk noise is less than 110 mV at 250 ps rising time. This connector can be used for high-speed data transmission of up to 300 ps rising time.