Semiconductor Package Metal Pillar Roughening for POP Adhesion
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Solution Overview
Problem
Current semiconductor packages face challenges in achieving improved rigidity and heat dissipation while maintaining effective adhesion between metal pillars and surrounding insulating materials, particularly in package-on-package structures.
Innovation Solution
The semiconductor package incorporates a vertical connection structure with a metal pillar and a plating layer having a roughened surface, enhancing adhesion between the metal pillar and the encapsulant and insulating layers, and includes a core structure with a metal frame and plating layer to improve rigidity and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal pillar is used for vertical connection, then electrical connection and rigidity are improved, but adhesion between the metal pillar and surrounding insulating material deteriorates
Solution Approach 1:
The surface roughness of the metal pillar is changed from a smooth state to a roughened state with Ra ≥ 0.5 μm. This parameter change increases the surface area and creates mechanical interlocking with the insulating material, thereby improving adhesion while maintaining the electrical connection and rigidity functions of the metal pillar
Solution Approach 2:
The metal pillar is combined with the insulating material through a roughened interface, creating a composite structure that leverages the electrical conductivity and rigidity of metal while achieving mechanical adhesion through the roughened surface topology. This composite approach resolves the contradiction between metal's inherent smooth surface and the need for strong bonding
2Volume of moving object
If a package-on-package structure is implemented, then miniaturization and performance improvement are achieved, but heat dissipation and rigidity become more challenging
Solution Approach 1:
The patent replaces traditional thermal management approaches with a metal pillar-based vertical connection structure that simultaneously provides electrical connection, mechanical support, and thermal conduction. The metal pillars act as heat sinks and thermal pathways, conducting heat away from the semiconductor chip vertically through the package structure, thereby improving heat dissipation in the compact POP configuration
3Volume of moving object
If a package-on-package structure is implemented, then miniaturization is achieved, but rigidity deteriorates
Solution Approach 1:
The metal pillars are embedded within the insulating material to form a composite structure that combines the high rigidity of metal with the structural integrity of the insulating material. This composite architecture provides enhanced mechanical strength and rigidity throughout the package, preventing deformation and maintaining structural stability in the miniaturized POP configuration
Solution Approach 2:
The metal pillars are strategically positioned at specific locations within the package to provide localized rigidity and structural support where needed. This local reinforcement approach maintains overall package rigidity without requiring increased size, allowing the POP structure to remain compact while achieving the necessary mechanical strength
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
This configuration reduces interfacial delamination and enhances the overall adhesion and thermal management of the semiconductor package, leading to improved reliability and performance in package-on-package structures.
Implementation Method 1
a plating layer on each of the bottom surface, the top surface, and the side surface of the metal pillar, and having a roughened surface
Data Source
AI summary
A semiconductor package includes a redistribution substrate including a first redistribution layer; a semiconductor chip electrically connected to the first redistribution layer; a vertical connection structure adjacent a periphery of the semiconductor chip and electrically connected to the first redistribution layer; and an encapsulant on the vertical connection structure. The vertical connection structure includes a metal pillar having a bottom surface facing the redistribution substrate, a top surface positioned opposite to the bottom surface, and a side surface positioned between the bottom surface and the top surface. The vertical connection structure further includes a plating layer on each of the bottom surface, the top surface, and the side surface of the metal pillar, and having a roughened surface.