| Type | 20L Rigid PCB Layout |
| Difficulty | 1.Very small, its main board is half the size of a common cell phone board.
2.Strange shape results in great limits for routing;
3.GSM & WCDMA dual-mode cell phone results in a large radio-frequency area.
4.Super-thin cell phone solution limits the board thickness; placing the whole radio-frequency module under the baseband chip results in great limits in hole drilling on the baseband chip;
5.Originally, ALIVH materials was to be used, but considering cost and risk reduction, we used second-order buried via scheme, but the routing requirements were not degrade. |
| Countermeasure | 1.By discussing with multiple PCB manufacture team, we set appropriate design parameters;
2.With RF experts’ participation in PCB design, strict design process assured signal quality of the board;
3.Careful optimization achieved the best coordination among requirements of different parties; |
| Result | Design fulfilled according to the plan, successful CAM and smooth debugging. |
