5G: advanced packaging technologies bring innovation

5G packaging brings innovative technology and new opportunities for SiP business.

“The RF components in the mobile are packaged at two levels,” asserts Santosh Kumar, Principal Analyst & Director Packaging, Assembly & Substrates, Yole Korea at Yole Intelligence, part of Yole Group.: “The 1st-level packaging of various RF components like filters, switches, and amplifiers at die/wafer level, includes RDL, TSV, and/ or bumping steps. Then the 2nd-level SiP packaging is performed at the SMT level where various components are assembled on SiP substrate along with passives.”

The 5G packaging market was US$0.52 billion in 2020 and is expected to grow at 31% CAGR to reach ~US$2.6 billion in 2026. The 5G packaging includes the RF modules with PAD, DRx FEM, etc. and AiP for 5G sub-6 GHz & 5G mmW connectivity.

In this context, the market research and strategy consulting company, Yole and its partner Yole SystemPlus investigates disruptive advanced packaging and RF electronics technologies and related markets in depth, to point out the latest innovations and underline 5G business opportunities.

Released today, the 5G Packaging Trends for Smartphones is a new Yole’s report which focuses on both the module and component packaging for 5G Sub-6GHz and 5G mmWave.
This study reveals in detail the 5G packaging market for smartphones and covers various RF front-end modules to support 5G communication, such as: 5G sub-6GHz RFFEM (PAMiD, DRx), 5G mmW AiP, 5G mmW discrete antenna, 5G mmW FEM.

What is the status of the 5G packaging technologies for smartphones? What are the economic and technical challenges? What are the opportunities and the key market drivers? Who are the suppliers to watch, and what innovative technologies are they working on?

Yole presents today its vision of the 5G packaging industry for smartphones.

As analyzed by Yole’s team in the new 5G Packaging Trends for Smartphones report, 5G sub-6 GHz RFFEM accounts for 67% of the total 5G packaging in 2026, followed by 5G mmW FEM, mmW AiP, and mmW discrete antenna.
In parallel, the AiP assembly market for mmW communication in mobile will grow by 40% to reach about US$448 million in 2026. AiP’s market share in the 5G packaging market will increase from 11% in 2020 to 17% by 2026.
In addition, 5G packaging substrate market will grow at CAGR ~35% to reach ~US$721 million in 2026. Low-loss substrate is essential to support 5G mmWave mobile communication and is required for the mmWave SiP, including AiP & discrete antenna.
According to Cédric Malaquin, Technology & Market Analyst, RF devices & technologies within the Power & Wireless division at Yole: “With the 5G specification, the number of RF paths has dramatically increased for both the downlink and the uplink. As a result, more dies or a larger one is needed to accommodate 5G signals along with 4G and other radios. As board space saving is key to the smartphone industry, RF Front End tier 1s such as Murata, Skyworks, Qorvo, Broadcom, and Qualcomm, along with OSAT companies, have been even more creative to enable component packing in sophisticated modules.”
In, the RF Front-End Module Comparison 2021 – Vol. 2 – Focus on 5G Chipset report released also today, the Senior Technology and Cost Analyst from System Plus Consulting, Stéphane Elisabeth, PhD. adds: “Based on our extensive database from 2020, the supplier rankings in terms of cost show the leadership of Qualcomm, followed by Broadcom and Qorvo, in the RF Front End for 5G phones. Almost half of the RFFE revenue per smartphone goes to Qualcomm. However, in the early 2021 5G phones, Qorvo has started the race for second place with some innovative modules that could disrupt the ranking.”

The various RF active & passive components in mobile are assembled in the SiP or remain discretes. LTE evolution has led to complex architecture in mobile phones, mainly due to carrier aggregation. Meanwhile, RF’s board area and available antenna space have been reduced, leading to a densification trend that sees more handset OEM s adopting power amplifier modules and implementing new techniques, i.e., antenna-sharing between LTE and WiFi.
According to Santosh Kumar: “5G added even more complexity requiring more densification in front-end modules to enable 5G sub-6 GHz & mmWave band integration. A single die is cost-efficient for components like tuners or discrete filters. For high-end phones, SiP technology is preferred for performance efficiency”.
Before 2018, LGA SiP was used in the RF industry. 4G LTE in smartphones used multi-die SiP (10-15 dies, utilizing flip-chip balls or Cu pillars or wire-bond to connect various components to the organic coreless substrate) for FEM, as well as for filter banks and diversity receive modules.
BGA has since been widely adopted thanks to the double-side packaging development. As an example, the recent version of the integrated RF SiP (MB/HB PAMiD) in the iPhone 12 is almost 50% smaller than the first mid/high-band PAMiD. Thanks to innovation, such as EMI shielding, Flip-Chip PA , or Double Side Molding BGA, Broadcom managed to integrate the same system in a smaller footprint.
Double-side BGA packaging technology brings advances in component density with a new type of internal shielding and isolation of critical components using the PCB substrate. Leading companies like Broadcom, Qorvo and Skyworks implement stepwise innovation in RF SiP, moving from LGA to DSBGA to DS-MBGA, whereas Murata directly implemented DS-MBGA for system integration & miniaturization.
RF system integration & miniaturization trends require innovation at various levels for 5G packaging in mobile. RFFEM supporting 5G sub-6 GHz utilize modifications of existing flip-chip laminate-based SiPs with a similar bill of materials: incremental innovation. On the other hand, 5G mmW brings disruptive packaging with the entry of new packaging architectures and platforms: fan-Out WLP and glass substrate interposers competing with advanced organic substrate flip-chip packages with new low-loss dielectrics.
“Antenna technology and placement is one of the most critical challenges for 5G semiconductor systems,” comments Santosh Kumar. “At mmWave frequencies, long paths from semiconductor packages to antennas represent high losses, making it desirable to integrate the antenna into the SiP. Higher frequencies require smaller antennas (mm instead of cm), which, from a footprint point of view, would be easier to integrate into SiPs.” In this context, various packaging solutions based on flip-chip & fan-out technology with different architectures are proposed for integrating antenna elements with RF components for 5G mobile communication.