Antenna-in-Package Layout for Low-Loss Millimeter-Wave RF Routing
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Solution Overview
Problem
Existing semiconductor packages face challenges in reducing transmission loss between antennas and RFICs, particularly at high frequencies such as millimeter waves, which is crucial for efficient 5G communication.
Innovation Solution
The semiconductor package incorporates a redistribution structure with a fine pitch redistribution conductor, a dielectric layer with a high dielectric constant, and a shielding layer to minimize transmission loss between the antenna and the RFIC. This configuration includes a frame surrounding the antenna structure to ensure thickness uniformity and reduce the height of the encapsulant, thereby minimizing signal loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional semiconductor package structure is used, then the device complexity is low, but the transmission loss of high-frequency signals between antenna and RFIC is high
Solution Approach 1:
The patent transitions from conventional two-dimensional planar routing to three-dimensional vertical stacking architecture. The antenna structure, redistribution layers, and RFIC are arranged in multiple vertical layers, allowing signal transmission paths to extend in the Z-direction (vertical) rather than only in the plane. This dimensional change enables shorter effective signal paths and better shielding while maintaining a compact footprint.
Solution Approach 2:
The patent implements nested encapsulation structures where a first encapsulant covers the antenna structure and a second encapsulant covers the RFIC, with both nested within a housing. The redistribution layers are also nested between the antenna and RFIC components. This nested arrangement provides electromagnetic shielding and physical protection while maintaining compact integration.
2Reliability
If the antenna and RFIC are integrated in a semiconductor package, then signal transmission efficiency is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs preliminary alignment actions during the manufacturing process. The antenna structure is first formed on a substrate with predetermined positions, then redistribution layers are deposited and patterned at specific locations relative to the antenna, and finally the RFIC is mounted and connected to predetermined pads. This sequential preliminary positioning ensures accurate alignment without requiring ultra-precision simultaneous alignment of all components.
Solution Approach 2:
The redistribution layers (first and second redistribution layers) serve as intermediary structures between the antenna and RFIC. These intermediate conductive layers provide multiple connection points and routing options, allowing for tolerance compensation and alignment adjustment. The encapsulants also act as intermediaries providing both mechanical support and electromagnetic coupling between the antenna and RFIC.
3Object-affected harmful factors
If encapsulants are used to cover antenna and RFIC, then protection and shielding are improved, but the height of the package increases
Solution Approach 1:
The patent applies different properties to different regions of the encapsulants. The first encapsulant covering the antenna has specific dielectric properties optimized for antenna performance, while the second encapsulant covering the RFIC has properties optimized for device protection. The housing material is also selected with specific electromagnetic shielding properties. This localized optimization provides effective EMI shielding without requiring excessive thickness throughout the entire package.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed solution effectively reduces transmission loss of high-frequency signals between the antenna and the RFIC, enhancing signal integrity and power integrity, and supporting efficient millimeter wave communication.
Implementation Method 1
a dielectric layer with a high dielectric constant
Implementation Method 2
a shielding layer surrounding a surface of the second encapsulant
Data Source
AI summary
A semiconductor package includes an antenna structure including an antenna member configured to transmit and receive a signal through the first surface in the dielectric layer, a connection via extending from the antenna member toward the second surface, and a ground member spaced apart from the connection via; a frame surrounding the side surface of the antenna structure; a first encapsulant covering at least a portion of the antenna structure and the frame; a redistribution structure on the second surface and including an insulating layer in contact with the antenna structure and the frame, and a redistribution conductor configured to be electrically connected to the ground member and the connection via in the insulating layer; a first semiconductor chip on the redistribution structure and electrically connected to the antenna member through the redistribution conductor; a second encapsulant encapsulating the first semiconductor chip on the redistribution structure; and a shielding layer surrounding a surface of the second encapsulant.