Fan-Out Semiconductor Package Warpage Control via Metal Posts
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Solution Overview
Problem
The challenge in the semiconductor industry is to control warpage in fan-out semiconductor packages when applied to package-on-package structures, as the thinning of lower fan-out packages leads to increased defects in solder joints during the stacking process.
Innovation Solution
A fan-out semiconductor package design is introduced, featuring a metal member with a metal plate and posts, a semiconductor chip, and an encapsulant, along with a wiring layer and connection member, which includes a redistribution layer. The metal member and interposer are used to control warpage and facilitate signal connection, preventing yield decreases and enabling easier application to package-on-package structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the lower fan-out package is thinned to reduce size, then the package size is reduced, but warpage occurs leading to solder joint defects
Solution Approach 1:
The patent changes the physical and chemical parameters of the package structure by introducing a metal plate with specific thickness (5-20 μm) and metal posts (10-30 μm height) into the core region. These parameter adjustments provide structural reinforcement that controls warpage while maintaining the thinned package profile, resolving the contradiction between size reduction and solder joint quality.
Solution Approach 2:
The patent employs composite material structure combining the metal plate, metal posts, encapsulant, and semiconductor chip. This composite approach creates a reinforced core region that resists warpage deformation during the stacking process, enabling both thin package design and reliable solder joints in package-on-package applications.
2Stability of the object's composition
If a metal member is introduced into the core region, then warpage is controlled, but device complexity increases
Solution Approach 1:
The metal member is segmented into distinct functional components: a metal plate providing broad structural support and multiple metal posts providing localized reinforcement and electrical connection points. This segmentation allows warpage control through distributed reinforcement rather than a single complex structure, simplifying the overall design while maintaining stability.
Solution Approach 2:
The metal plate and metal posts serve multiple functions simultaneously: structural reinforcement to control warpage, electrical connection pathways for signals, and mechanical support for the semiconductor chip. This multi-functionality reduces the need for separate components, thereby controlling device complexity while achieving warpage control.
3Adaptability or versatility
If the metal posts are spaced apart from the metal plate, then signal connection is facilitated, but manufacturing precision requirements increase
Solution Approach 1:
The metal posts are pre-formed and positioned on the metal plate before final encapsulation. This preliminary action allows for precise positioning to be established early in the manufacturing process, with subsequent steps (encapsulation, wiring layer formation) building upon this established geometry, thereby reducing the cumulative precision requirements.
Solution Approach 2:
The encapsulant serves as an intermediary material that fills the spaces between the metal posts and metal plate, providing mechanical support and electrical insulation. This intermediary allows the metal posts to be spaced apart for signal connection while the encapsulant maintains structural integrity, reducing the stringency of positioning precision requirements.
Data Source
AI summary
The fan-out semiconductor package includes: a metal member including a metal plate having a first through-hole and second through-holes and metal posts disposed in the second through-holes; a semiconductor chip disposed in the first through-hole; an encapsulant covering at least portion of each of the metal member and the semiconductor chip and filling at least portions of each of the first and second through-holes; a wiring layer disposed on the encapsulant; first vias electrically connecting the wiring layer and the connection pads to each other; and second vias electrically connecting the wiring layer and the metal posts to each other, wherein a height of the second vias is greater than that of the first vias or a thickness of the metal plate is the same as that of the metal post.