RF Devices And Technology

First High-Volume Manufacturing (HVM) BAW filter on the market from Skyworks, integrated in the Apple iPhone 11 Pro Max and iPad Pro second generation.

In the smartphone market Apple is one of the most profitable companies, with around a 40% share of the market in 2018. The overall smartphone market is worth more than $400 billion. Module and filter manufacturers must be reliable and highly innovative to match Apple’s spirit if they want to be a supplier. Until 2019, Skyworks was known for its high-performance Surface Acoustic Wave (SAW) filters and Low-Band/Mid-Band modules. Today, with its newly developed Bulk Acoustic Wave (BAW) filter in High Volume Manufacturing (HVM), the company is embracing the 5G Sub-6GHz wave by offering an Ultra High Band (UHB) module. By doing so, Skyworks is now able to compete with Qorvo or Broadcom in these frequencies.

In 2019 and 2020, Skyworks is supplying Apple with Power Amplifier Modules (PAMs) that feature 2G connectivity and UHB Front-End in the same package. The module is integrated in the Apple iPhone Series 11, 11 Pro and 11 Pro Max, but also in the latest Apple iPad Pro second generation, as the SKY78201 model. Depending on the version, the module features several dies: a Power Amplifier (PA), Silicon-on-insulator (SOI) Switch and Low-Noise Amplifier (LNA), Integrated Passive Device (IPD), SAW Filter and Film Bulk Acoustic Resonator (FBAR) filters.

This report will only focus on the FBAR filters. The component is using an innovative silicon cap bonded wafer Chip-Scale Packaging (CSP) technology with Through-Silicon Vias (TSVs) enabling electrical contacts and scandium doped Aluminum Nitride (ScAlN) as a piezoelectric material. This newly developed device implements a simple ladder structure with a density comparable to its major competitor. To seal the internal structure, the packaging uses eutectic bonding with Au-Sn solder.

The report contains a deep analysis of the filter die with a complete cost analysis of the component. It also integrates a comparison with the Broadcom’s FBAR and Qorvo’s Solidly Mounted Resonator (SMR) BAW filter technology also integrated in the Apple iPhone series.

 

Overview/Introduction

Skyworks Company Profile

Apple iPhone 11 Pro Max – Teardown

Market Analysis

Physical Analysis

• Physical Analysis Methodology
• Package
  • View and dimensions
  • Package opening
• Filter Die
  • View, dimensions, opening and markings
  • Die overview and schematic
  • Die overview: cap, substrate, cells
  • Die cross-section: sealing frame, anchor, TSV, holes, FBAR structure
• Filter Physical Data Summary

Manufacturing Process Flow

• Filter Wafer Fabrication Unit
• Filter Process Flow

Analysis

• Cost Analysis Overview
• Main Steps Used in the Economic Analysis
• Yield Hypotheses
• Filter Die Cost
  • Filter wafer front-end cost per process step
  • Wafer and die cost

Comparison with Broadcom’s FBAR and Qorvo’s SMR BAW Filter

• Integrated Passive Devices Comparison 2021
• Skyworks’ 2nd Gen. FBAR-BAW in MB/HB Diversity SKY53X17
• Oppo Reno3 5G Sub-6 Front-End Modules
• SAW Filter Comparison 2020
• Advanced RF SiPs for Cell Phones: Reverse Costing Overview
• Broadcom AFEM-8215-PAMiD in iPhone 13 series
• Google Pixel 6 Pro mmWave 5G Chipset
• Qualcomm Thin-Film SAW Filter Technology in Diversity Module
• RF Front-End Module Comparison 2021 – Volume 4 – Focus on WiFi 6/6E
• RF Front-End Module Comparison 2021 – Volume 3 – Focus on Samsung