single connector attachment (SCA)
The SCA connector represents an industry standard developed by the storage industry to provide a direct plug-in connection from hard disk drives and Fibre Channel storage media to the backplane.
Drives can be connected directly to the backplane, eliminating the need for additional adapter boards and interconnect cables.
The SCA connector consists of a slot located in a guide housing that is soldered directly onto the PCB.
These connectors are available with 40 and 80 pins and heights of 11.5 mm and 17.5 mm, among others. The 40- pin version is used in Fibre Channel; the 80-pin in connection with SCSI 3 Parallel Interface( SPI-2).