A novel low-profile low-parasitic RF package using high-density build-up technology

This paper presents a low-profile low-parasitic RF package by using the high-density build-up (HD-BU) technology. This package achieves much thinner, fine pitch, and exposed design pattern feature for outstanding electrical and thermal performance. The packaging fabrication is simple and only needs several processes. This HD-BU package provides lower parasitic than other lead-frame types due to the use of very thin bonding pads. Additionally, a capacitor chip is assembled using the proposed technology for packaging demonstration and electrical performance evaluation. Based on the experimental results, the measured capacitances at 1-GHz are quite similar before and after packaging. It indicates that the HD-BU package has low parasitic capacitance even at high-frequency operation, and does not affect the electrical performance for the packaged chip. Therefore, these packages are good candidates for applications requiring low profile, low parasitic and low cost.