Semiconductor Device With Elastic Member for Fine Pitch Bumps
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Solution Overview
Problem
Conventional wafer level package (WLP) structures face challenges in achieving fine pitch conductive bumps due to the complexity in controlling the number and pitch spacing of conductive bumps made of solder material, leading to bulkiness and inefficiency in semiconductor devices.
Innovation Solution
A semiconductor device is fabricated with an electrically conductive elastic member on which a conductive bump is formed, allowing for reduced height and diameter of the bump, enabling fine pitch realization and mitigating external impacts through the use of an elastic material, along with a redistribution layer and insulating passivation layer to facilitate efficient signal transmission and protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conductive bumps are directly formed on semiconductor dies in conventional WLP structure, then multiple input/output terminals can be achieved, but the structure becomes bulky and controlling the number and pitch spacing of conductive bumps becomes complex
Solution Approach 1:
An elastic member is introduced as an intermediary between the semiconductor die and the conductive bumps. This elastic member serves as a base structure that simplifies the formation process of conductive bumps while enabling better control over their number and pitch spacing, thereby resolving the complexity issue in conventional direct formation methods
Solution Approach 2:
The patent changes the physical state and properties by introducing an elastic member with specific mechanical properties. This elastic member can be deformed during the bump formation process, allowing for precise control of bump pitch and spacing parameters that would be difficult to achieve with rigid direct formation methods
2Reliability
If conductive bumps are made of solder material in conventional WLP structure, then electrical connection is achieved, but the structure becomes bulky
Solution Approach 1:
The patent changes the dimensional parameters by using an elastic member as a base, which allows conductive bumps to be formed with reduced height and diameter. The elastic member's deformability enables compact bump geometry while maintaining electrical connection reliability, thus reducing the overall volume of the WLP structure
3Stability of the object's composition
If rigid conductive bumps are used, then structural stability is maintained, but external impacts are transferred to the semiconductor die
Solution Approach 1:
The elastic member serves as a pre-positioned cushioning element between external sources and the semiconductor die. When external impacts occur, the elastic member deforms to absorb and dissipate the impact energy before it reaches the die, thereby protecting the semiconductor device while maintaining structural stability
Solution Approach 2:
The patent changes the mechanical property parameter from rigid to elastic for the intermediate structure. This elastic property allows the structure to dynamically respond to external forces through deformation, providing impact mitigation while maintaining overall structural integrity and stability
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 solution allows for the achievement of fine pitch conductive bumps while reducing external impacts on the semiconductor die, enhancing signal transmission efficiency and manufacturing reliability by using an elastic member as a base for the conductive bumps, thus addressing the bulkiness and complexity issues of traditional WLP structures.
Implementation Method 1
the elastic member is elastic and thus mitigates external impacts from being transferred from the conductive bump to the semiconductor die
Data Source
AI summary
A semiconductor device and a fabrication method thereof are provided. An electrically conductive elastic member is formed on a semiconductor die, and a conductive bump is formed on the elastic member. Accordingly, since the conductive bump is formed on the elastic member, or to protrude from a top surface of the elastic member, the height and thus diameter of the conductive bump is reduced allowing a fine pitch to be realized. Further, the elastic member is elastic and thus mitigates external impacts from being transferred from the conductive bump to the semiconductor die.