Mold-based compartment shielding to mitigate the intra-system coupled noise on SiP modules

A new technology based on conformal shielding technique called compartment shielding is proposed to isolate the coupled noise between the digital and RF/analog circuits inside system-in-package (SiP) modules. The technology is realized by using a tooth-shaped metal frame to separate different functional circuits. It provides an excellent shielding effectiveness (SE) and reduces the cost, dimensions, and weight compared to the conventional solution. Based on our experience, a test vehicle is designed with a broadband near-field source to evaluate the SE from 0.1 GHz to 10 GHz. The vector network analyzer (VNA) set up with an extremely low noise floor is utilized to measure the insertion loss of the test vehicle. From the measured results, the SE reaches approximately 30 dB before the first resonance appears. The discrepancy between the simulation and measurement are dominated by the fabrication errors and the power leakage at the transitions; however, the isolation over 100 dB with the proposed shield is good enough for many commercial applications, such as hand-held devices and wireless connectivity modules.