There are many different kind of D-sub connectors, or similar connectors which use jackscrew to mount the connectors. The jackscrew height is critical for the connector function, IPC-A-620 defined the spec for it.
The height relationship of the face of the jackscrew to the associated connector face. This is critical to obtain maximum connector pin contact.
Hardware stack-up for mounted connectors may be varied in order to locate the face of the jackscrew flush to 0.75 mm [0.030 in] below the face of the connector.
Target - Class 1,2,3
• Jackscrew face is flush to 0.75 mm [0.030 in] below the
face of the connector.
• Height is obtained by adding or removing washers (supplied
with jackscrews).
Defect - Class 1,2,3
• Jackscrew face extends above the connector face (Figure 9-2).
• Face of Jackscrew is greater than 0.75 mm [0.030 in] below
the connector face (Figure 9-3).
