Stacked Die Packaging Structure Without Copper Pillars
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing die packaging structures require significant longitudinal space due to copper pillars used for interconnecting dies, leading to increased thickness and inefficiencies.
Innovation Solution
A packaging structure is designed with first and second packaging modules, where dies within each module are arranged in a thickness direction and connected vertically through metal balls, eliminating the need for copper pillars between certain dies to reduce longitudinal space occupation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper pillars are used to interconnect adjacent dies, then electrical connection between dies is achieved, but the packaging structure thickness increases
Solution Approach 1:
The patent merges the electrical connection function into the bonding interface itself by using metal balls at the bonding pads. The first and second dies are bonded directly to each other with metal balls providing electrical connection, eliminating the need for separate copper pillars. Similarly, the third and fourth dies are bonded directly. This merging of bonding and electrical connection functions reduces the overall packaging thickness while maintaining reliable electrical connectivity between all dies.
Solution Approach 2:
The patent extracts the copper pillar interconnection element from the packaging structure. Instead of using copper pillars to connect dies vertically, the invention uses direct bonding with metal balls at the bonding pads. This extraction of the copper pillar component eliminates the longitudinal space that copper pillars would occupy, thereby reducing packaging thickness while preserving electrical connection functionality.
2Speed
If multiple dies are arranged vertically with copper pillars, then data transmission between dies is enabled, but longitudinal space is occupied increasing module thickness
Solution Approach 1:
The patent merges the data transmission pathway with the bonding structure. By placing metal balls directly at the bonding pads and bonding dies directly to each other, the electrical connection path for data transmission is established through the bonding interface itself rather than through separate copper pillars. This merging enables efficient data transmission while minimizing the vertical space required.
3Reliability
If copper pillars are used for die interconnection, then electrical connectivity is maintained, but manufacturing complexity increases
Solution Approach 1:
The patent extracts the copper pillar manufacturing process from the packaging workflow. By using direct bonding with pre-formed metal balls at the bonding pads, the complex processes of copper pillar formation, alignment, and integration are eliminated. This simplification reduces manufacturing complexity while maintaining reliable electrical connectivity through the direct bond interface.
Solution Approach 2:
The patent applies preliminary action by pre-forming metal balls at the bonding pads before the bonding process. This preliminary preparation of electrical connection elements eliminates the need for complex in-process copper pillar formation and alignment operations, thereby simplifying the overall manufacturing process while ensuring reliable electrical connectivity.
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 approach reduces the thickness of the packaging module, enhances signal transfer speed, simplifies manufacturing, and improves production efficiency while maintaining electrical connectivity.
Implementation Method 1
The fourth die and the first die are electrically connected
Implementation Method 2
bonding the second die to the first die, to obtain a first packaging module; bonding the third die to a fourth die on a fourth wafer
Data Source
AI summary
A packaging structure, an electronic device, and a packaging method are provided. The packaging structure includes a first packaging module and a second packaging module. The first packaging module includes a first die and a second die, the first die and the second die are arranged in a thickness direction of the first die, and the first die and the second die are electrically connected. The second packaging module and the first packaging module are arranged in the thickness direction, the second packaging module includes a third die and a fourth die, the third die and the fourth die are arranged in the thickness direction, and the third die and the fourth die are electrically connected. The fourth die and the first die are electrically connected.