Variable-Width Conductive Posts for Reliable Fan-Out Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages face challenges in achieving a small size with multiple input and output terminals while maintaining reliability and productivity, particularly in fan-out wafer level packages.
Innovation Solution
A semiconductor package design featuring a conductive post with a variable width middle portion and a manufacturing method that involves controlled plating processes to form the conductive post, ensuring consistent widths at the lower and upper portions and varying the middle portion to enhance reliability and productivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional conductive post with constant width is used, then the manufacturing process is simple, but cracks occur at the conductive post interfaces reducing reliability
Solution Approach 1:
The conductive post employs different width characteristics at different portions: the lower and upper portions have constant widths for stable connection, while the middle portion has a non-constant width that tapers. This local differentiation optimizes both connection reliability and stress distribution without unnecessarily complicating the overall structure.
Solution Approach 2:
The conductive post transitions from a static constant-width structure to a dynamic variable-width structure where the middle portion's width changes along its length. This dynamic geometry adapts to stress distribution patterns, reducing crack propagation while maintaining manufacturing feasibility through controlled plating processes.
2Productivity
If a constant width conductive post is used, then the plating process is straightforward, but molding material flow is restricted
Solution Approach 1:
The variable width of the middle portion creates localized flow channels that facilitate molding material movement. The tapered geometry allows material to flow more easily through the conductive post region during the molding process, improving productivity without requiring complex multi-step plating procedures.
3Reliability
If the conductive post has uniform width, then manufacturing is easier, but crack prevention at interfaces is insufficient
Solution Approach 1:
The invention changes the geometric parameter (width) of the conductive post along its length. By varying the width in the middle portion while keeping the lower and upper portions at constant widths, the structure achieves better crack prevention through stress distribution without making the manufacturing process excessively complex.
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 design prevents cracks at the conductive post interfaces and improves the flow of molding material, enhancing the reliability and productivity of the semiconductor package.
Implementation Method 1
forming a conductive post by plating a conductive material within the opening portion
Data Source
AI summary
A semiconductor package includes a first redistribution structure, a semiconductor chip on the first redistribution structure, a molding member on the first redistribution structure and the semiconductor chip, a second redistribution structure on the molding member, and a conductive post between the first redistribution structure and the second redistribution structure that electrically connects the first redistribution structure and the second redistribution structure. The conductive post includes a lower portion connected to the first redistribution structure, an upper portion connected to the second redistribution structure, and a middle portion between the lower portion and the upper portion. A width of the middle portion in a horizontal direction, parallel to an upper surface of the first redistribution structure, is not constant.