Chip Scale Review - March April 2020

12 Chip Scale Review March • April • 2020 [] Antenna in package (AiP) technology for 5G growth By Curtis Zwenger, Vik Chaudhry [Amkor Technology, Inc.] ntenna i n package (Ai P) o r a n t e n n a o n p a c k a g e (AoP) simplify challenges associated with mmWave applications and expedites system design. Today’s AiP technologies can be implemented through standard or custom system in package (SiP) modules. This article provides an in-depth look at the different AiP options, shielding, material selection, and best use cases in emerging 5G applications. 5G applications and projected growth The driving forces for implementing 5th generation new radio 5G (NR) or simply 5G technology, include the transmission of large data rates as well as the need for more reliable connections, quicker response time (low latency) and better coverage. In mmWave applications, signal loss becomes critical and design challenges increase in complexity. In addition to emerging 5G smartphones, other applications that operate at very high frequencies and demand a small size include wearables, small cells, security cameras, radar units in autonomous vehicles and numerous Internet of Things (IoT) appliances. By 2023, over 1 billion mmWave units will be produced annually according to Gartner, Inc. market research. With AiP technology, the antenna is no longer a separate component within the wireless device but is integrated in a SiP with radio frequency (RF) switches, filters and amplifiers. According to consulting firm Yole Développement, the total RF front-end (RFFE) module SiP market is projected to reach US $5.3 billion by 2023, representing an 11.3% compound annual growth rate (CAGR) ( Figure 1 ). Another market forecast projects the 5G mmWave market to increase tenfold by 2025 [1]. The supporting base station and small cell infrastructure will require a tremendous amount of semiconductor packaging and system integration support. Outsourced semiconductor assembly and test (OSAT) suppliers are typically best suited to invest in the package development and production scaling for such applications by leveraging their broad customer and supply base. 5G AiP technology Instead of separate power amplifiers ( PA), low-noise ampl if ie r s (LNA), switches, transceivers, f ilters and a discrete antenna, today’s fully-integrated RFFE module is completely achieved with AiP technology in a SiP. The integration is accomplished using SiP technologies, i ncl ud i ng double - side d a s s embly, advanced wafer-level redistribution layers (RDL), passive component integration and sophisticated RF shielding techniques to provide the most advanced 5G package solutions available today. A In addition to the reduced size required for handheld and other small mmWave devices, AiP provides improved signal integrity with reduced signal attenuation and addresses the range and propagation challenges that occur at higher frequencies. Among the changes occurring with the transition from 4G long-term evolution (LTE) to the 6 to 60GHz of 5G are increased RF switch and band complexity (from 40 bands x3 carrier aggregations [CAs] to 50 bands x5 CAs) and increased antenna design and tuning complexity (from 8x8 multiple input and multiple output [MIMO] to 68x4 MIMO). To achieve the promised improvements of 5G (see Figure 2 ), many of the technical challenges must be addressed at the package level. Figure 1: The market for mmWave devices is expected to grow to 1 billion units by 2023. SOURCE: Gartner, Small cells market status report, December 2018 Figure 2: The use of 5G technology provides significant advantages over previous generations. SOURCE: Raconteur