高速SMA过孔阻抗设计优化

Optimize of High Speed SMA Via Impedance Design

高速网络系统详细设计前必须进行原型测试,以保证系统稳定性。SMA过孔是原型系统的重要组成。对于短线互连通道,重点关注SMA过孔的阻抗性能。SMA过孔阻抗性能是保证SerDes性能与PCB工程设计评估的重要前提。论文分析了SMA过孔阻抗的影响因素,并通过3D模型仿真与实物测试SMA过孔阻抗,结果显示去除非功能焊盘与双径隔离盘设计可以有效提高SMA阻抗到通道阻抗的10%内。该方法适用于多层印制板的通孔结构,相比盲埋孔工艺可有效降低印制板制造成本。

Prototype testing must be performed before detailed design of high-speed network systems which ensure the system stability.SMA via is an important component of a prototype system.Attention must be paid to impedance of via for short reach channel.SMA via impedance performance is an important prerequisite for evaluating SerDes performance and PCB engineering design.This paper analyzes the influencing factors of SMA via impedance and tests the SMA via impedance through 3 D model simulation and physical testing.The result reveals that the removal of nonfunctional pads and the twin diameter anti pad can effectively increase the SMA impedance to within 10%of the channel impedance.The method is applicable to the through-hole structure in multi-layer PCB,and the manufacturing cost of the printed board can be effectively reduced compared to the blind or buried via process.