过孔

过孔是印刷电路板（PCB）中镀铜的通孔，用于在导电层之间提供电气和热连接。它们对于多层PCB设计至关重要，允许信号、电源和接地层垂直穿过电路板。过孔通常通过在PCB基板上钻孔，然后电镀铜以形成导电孔壁来制造。它们可分为通孔（贯穿所有层）、盲孔（连接外层和内层）和埋孔（仅连接内层）。先进技术包括微孔（直径<150 μm）和用于高密度互连（HDI）应用的填充孔。

过孔通过创建穿过PCB绝缘基板的导电通路来工作。钻孔后，孔壁通过化学镀铜和电镀进行金属化，形成连续的导电孔壁。这使得电流和信号能够在层间传递，实现复杂的电路布线。在热管理中，过孔将热量从元件传递到其他层或散热器。电气性能取决于纵横比、镀层质量和过孔几何形状等因素，对于高频应用，阻抗匹配至关重要。

Vias function by creating a conductive path through the insulating substrate of a PCB. After drilling, the hole walls are metallized via electroless copper deposition followed by electroplating, forming a continuous conductive barrel. This allows electrical currents and signals to pass between layers, enabling complex circuit routing. In thermal management, vias transfer heat from components to other layers or heat sinks. The electrical performance depends on factors like aspect ratio, plating quality, and via geometry, with impedance matching critical for high-frequency applications.