A novel TSV interposer based System-in-Package for RF applications

In this paper, a TSV interposer base SIP for RF applications is proposed. It’s composed of two separate TSV interposers based on high resistivity Si substrate, which is utilized as the substrate and Cap for RF SIP package. Choice of high resistivity Si substrate is intended to relieve RF loss. The one used for SIP package substrate is consisted of Cu TSVs, RF transmission lines and cavities, the cavity is coated with Copper layer inside, populated with electrical grounding Cu TSVs at the bottom surface, surrounded by lines of TSVs, and it’s utilized to accommodate RF microelectronic chips. The other one used for capping is similar to the bottom TSV interposer in structure. The two TSV interposers will be aligned in the final step with the cavities being sealed to form a close room for the inside RF device for improving the property in electromagnetic compatibility. To demonstrate TSV interposer based RF SIP, Process is developed for the TSV interposer. To testify theprocess, a test vehicle is designed and TSV interposer is fabricated, assembled and characterized.