Semiconductor Package Metal Post Structure for Reliable Bump Connection
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Solution Overview
Problem
The connection reliability between a semiconductor package and a substrate is affected by the state of the connection bump and the redistribution layer, leading to challenges in enhancing board level reliability.
Innovation Solution
A semiconductor package design that includes a redistribution substrate with a metal post of increased height, which is electrically connected to the redistribution pattern and encapsulated by an insulating layer, and a connection bump directly contacting the metal post to prevent defects caused by high-density currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional connection bump structure is used directly on the redistribution layer, then the structure is simple, but the connection reliability is insufficient due to high-density current defects
Solution Approach 1:
A metal post is introduced as an intermediary structure between the connection bump and the redistribution layer. The metal post serves as a mediator that distributes the high-density current from the connection bump over a larger area, preventing current concentration defects while maintaining structural simplicity. The metal post is electrically connected to the redistribution pattern through a via structure, enabling it to function as an effective current distribution pathway.
2Reliability
If the metal post height is increased to improve current distribution, then the current distribution area increases, but the manufacturing precision requirements increase
Solution Approach 1:
The metal post height is optimized to a specific range (50-100 μm) to achieve effective current distribution without excessive complexity. This parameter optimization balances the need for sufficient current distribution area with the practical constraints of manufacturing precision. The via structure connecting the metal post to the redistribution pattern is also designed with controlled dimensions to ensure reliable electrical connection while maintaining manufacturability.
Data Source
AI summary
A semiconductor package includes a redistribution substrate having first and second surfaces opposing one another, a first semiconductor chip on the first surface of the redistribution substrate, a passive device and a metal post on the second surface of the redistribution substrate and electrically connected to the redistribution pattern, a second encapsulant encapsulating at least side surfaces of the passive device and the metal post, a second insulating layer on a lower surface of the metal post and a lower surface of the second encapsulant, and having an opening exposing at least a portion of the lower surface of the metal post, and a connection bump filling the opening of the second insulating layer and in direct contact with the lower surface of the exposed metal post, wherein the metal post has a height greater than a height of each of the redistribution pattern and the redistribution via.