An Ultracompact, Low-Cost, and High-Performance RF Package Technique for Wi-Fi FEM Applications

With the advent of next-generation Wi-Fi technology, the demand for shrinking Wi-Fi front end module (FEM) product size is voracious. In this letter, a novel package technique called hot-via chip-scale package (HVCSP) is proposed. HVCSP has benefits such as ultrasmall package size, low cost, bump-free, substrate-free, and outstanding RF performance. In this letter, a 5-GHz Wi-Fi FEM using GaAs-based Bi-HEMT technology and HVCSP is also demonstrated. Due to the wire and lead frame-free structure, the package size can be further reduced by over 40% compared to the traditional QFN package. By employing a hot-via transformer structure, the measurement loss from chip to package is below -0.5 dB from 0 to 67 GHz. With these advantages, HVCSP is suitable for Wi-Fi FEM applications perfectly.