Semiconductor Package Redistribution Structure for Reliable Die Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The reliability of electrical connections between conductive terminals and internal components in semiconductor packages is a challenge due to the limitations in existing wafer-level packaging technologies, particularly in ensuring consistent and durable connections during the fabrication and integration of semiconductor dies and redistribution structures.
Innovation Solution
A method involving a carrier with a buffer layer, through insulator vias, and semiconductor dies is used, where the buffer layer includes a de-bonding layer and a dielectric layer, and the semiconductor dies are encapsulated with an insulating material, followed by a redistribution structure formation with conductive via portions and body portions embedded in dielectric layers, and a cleaning process to achieve smooth surfaces and reliable connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wafer-level packaging is used to integrate multiple semiconductor devices, then productivity and integration density are improved, but the reliability of electrical connections between conductive terminals and internal components deteriorates
Solution Approach 1:
The conductive posts are formed with protruding portions that extend beyond the insulating encapsulant surface before final packaging. This preliminary action ensures that the connection interfaces are established and protected in advance, maintaining connection reliability while enabling wafer-level integration of multiple devices.
Solution Approach 2:
The conductive posts have different structural characteristics at different locations: the main body is embedded in the semiconductor device for electrical connection, while the protruding portions extend outward for external connectivity. This local differentiation allows the same structure to serve multiple functions, ensuring both integration density and connection reliability.
2Ease of operation
If conductive posts are formed with protruding portions for external connections, then ease of connection is improved, but the risk of collapse and manufacturing defects increases
Solution Approach 1:
The insulating encapsulant is formed to substantially level with the top surfaces of the conductive posts, providing mechanical support and protection to the protruding portions before final connection operations. This prevents collapse during handling and assembly while maintaining ease of connection.
Solution Approach 2:
The package structure combines conductive materials (copper, aluminum, or tungsten) for the posts with insulating materials (epoxy, polyimide, or PBO) for the encapsulant. This composite construction provides both electrical connectivity and mechanical stability, preventing collapse while enabling easy external connections.
3Reliability
If the top surface of conductive posts is cleaned to improve connection quality, then electrical connection reliability is improved, but surface roughness control becomes more difficult
Solution Approach 1:
The cleaning process parameters (time, temperature, chemical composition) are optimized to achieve the desired balance: long enough to remove contaminants and improve connection reliability, but controlled to maintain surface roughness within acceptable limits for subsequent bonding operations.
Solution Approach 2:
Traditional mechanical cleaning methods are replaced with chemical cleaning processes (acid dips, plasma treatment, or vapor phase cleaning) that can effectively remove contaminants and improve connection reliability without causing mechanical damage or excessive surface roughness.
Data Source
AI summary
A package structure includes at least one semiconductor die, an insulating encapsulant and a redistribution structure. The at least one semiconductor die has a plurality of conductive posts, wherein a top surface of the plurality of conductive posts has a first roughness. The insulating encapsulant is encapsulating the at least one semiconductor die. The redistribution structure is disposed on the insulating encapsulant in a build-up direction and is electrically connected to the at least one semiconductor die. The redistribution structure includes a plurality of conductive via portions and a plurality of conductive body portions embedded in dielectric layers, wherein a top surface of the plurality of conductive body portions has a second roughness, and the second roughness is greater than the first roughness.