Redistribution Circuitry Direct Bonding for Thinner IC Packages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional package structures for integrated circuits are hindered by the substantial thickness occupied by copper pillars, making it challenging to miniaturize while maintaining process simplicity.
Innovation Solution
A package structure is designed with a first and second redistribution circuitry, where the layout density of bottom conductive pads is greater than that of top conductive pads, allowing direct copper-to-copper bonding without conductive pillars, enabling a thinner package structure while maintaining process simplicity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper pillars are used to connect redistribution circuitries, then electrical connection is achieved, but package thickness increases substantially
Solution Approach 1:
The patent removes the copper pillar intermediate structure from the conventional package architecture. Instead of using topological redistribution layer-bottomological redistribution layer-copper pillar-chip structure, it directly bonds topological redistribution layer to chip, extracting the thickness-consuming copper pillar while maintaining electrical connection functionality through direct copper-to-copper bonding.
Solution Approach 2:
The patent merges the functions of the copper pillar and the bonding interface into a single direct bonding joint. By directly bonding the first redistribution circuitry to the second redistribution circuitry without intermediate copper pillars, it combines the electrical connection function and mechanical support function into one integrated interface, reducing overall package thickness.
2Length of stationary object
If package structure is miniaturized by removing copper pillars, then thickness is reduced, but manufacturing complexity may increase
Solution Approach 1:
The patent employs self-alignment and self-bonding mechanisms where the direct copper-to-copper bonding process inherently aligns the bonding interfaces through surface preparation and bonding pressure application. The process leverages the natural properties of copper surfaces and bonding physics to achieve alignment without requiring complex external alignment systems or additional alignment steps.
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 direct bonding of redistribution circuitries results in a thinner package structure, achieving miniaturization without increasing complexity in the manufacturing process.
Implementation Method 1
Each of the second bottom conductive pads is directly coupled to a corresponding one of the first top conductive pads
Data Source
AI summary
A package structure including a first redistribution circuitry and a second redistribution circuitry is provided. The first redistribution circuitry has a plurality of first top conductive pads and a plurality of first bottom conductive pads. A layout density of the first bottom conductive pads is greater than a layout density of the first top conductive pads. The second redistribution circuitry is disposed on the first redistribution circuitry and electrically connected to the first redistribution circuitry. The second redistribution circuitry has a plurality of second top conductive pads and a plurality of second bottom conductive pads. A layout density of the second bottom conductive pads is greater than a layout density of the second top conductive pads. Each of the second bottom conductive pads is directly coupled to a corresponding one of the first top conductive pads. A manufacturing method of a package structure is also provided.