埋入电镀电阻在高速线路中的应用

埋入电阻是实现高频电路的重要方法之一。现已开发出在内层要求精确电镀上电阻元件的工艺,这意味着PCB制造厂可采用各种类型层压板材料,根据不同电镀时间得到从25 Ω到100 Ω范围内的方块电阻值(电阻率),而不是采用各种不同电阻值金属箔的基材来制备不同阻值的埋入电阻。采用常规PWB的活化和化学镀等制造步骤便可制作这种电阻,这种埋入电阻工艺是易于激光检修并层压到多层板内部是很稳定的。这种埋入电阻经过多层层压,温度变化或者显露于潮湿环境下表明电阻值是很小改变的,经过模拟电路运作具有好的稳定性。

Plated Embedded Resistors for High Speed Circuit Application

Embedded resistors are one of the enabling technologies for high frequency copper circuitry. A process has been developed to plate resistor elements exactly where required on inner layers. This means the circuit board fabrication shop can use a variety of laminate materials, can vary the resistivity from 25 to 100 ohms per square (based on plating time), and not inventory resistor foils as raw materials. Normal printed wiring board fabrication steps of activation and electroless plating are utilized to form the resistors. The process has been shown to make stable easily laser trimmable resistor elements that are laminated inside multilayer printed circuit boards. The resistors show little change with multilayer pressing, little change with temperature change or exposure to moist atmospheres,and good stability with simulated circuit operation.