Highly reliable processes for embedding discrete passive components into organic substrates
There have been strong demands for a miniaturization and multi-functionalities in the recent electronics, especially in the portable ones. To meet both requirements, passive and/or active devices embedding into PCBs have been regarded as a most promising technique. In this paper, we propose a simple and quite cost effective method for fabricating discrete component embedded PCBs. Discrete components are embedded in cavities formed in the core layer of the PCB, and the external electrodes of the discrete components are connected by a Cu platting and etching method without any additional laser via machining or soldering processes. A prototype is successfully fabricated using MLCCs and chip resistors, size of 0603 in mm scale, and the capacitance and the resistance was measured to be little affected by embedding processes; they were changed by 0.2% and 0.6%, respectively. And they showed good reliabilities under harsh environmental tests including Pb-free reflow conditions.