To protect the mating connector from over mechanical stress and to minimize strain during board-to-board assembly, it is important to tighten the standoff nut in a specific sequence. The recommended mechanical standoff tightening sequence (S > W > N > E) is shown in the following figure. Once the S and W nuts are tightened, the SOM board is almost flat to the carrier card. The subsequent tightening of nuts N and E ensure the SOM and carrier connectors are completely engaged.
Figure 1.
K26 SOM Connector Mating Sequence
The recommended torque driver setting and operation parameters are specified in the following table.
Torque Driver | Controller Module | Torque Driver | Torque Setting | Assembly Duration | RPM Setting for Each Step |
---|---|---|---|---|---|
Smart Torque Electrical Driver | Atlas Copco MTF600 | ETD M 50 ABL V2 |
3.0 in.lbs (±0.5 in.lbs) |
10 secs | Step 1: 300 RPM |
Step 2: 600 RPM | |||||
Step 3: 150 RPM |