Semiconductor Package Structure Without Passivation Layer
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Solution Overview
Problem
The semiconductor industry faces manufacturing challenges in developing new packaging technologies for semiconductor devices, particularly in reducing fabrication costs and time while maintaining high integration density and functionality.
Innovation Solution
A package structure is formed by bonding a semiconductor substrate with a conductive feature to a substrate through a bonding structure that includes an under-bump metallization (UBM) layer, conductive pillar, and solder bump, without the need for a passivation layer, thereby reducing fabrication costs and time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional packaging technologies are used, then manufacturing process is well-established, but fabrication cost and time are high
Solution Approach 1:
The patent extracts and eliminates the passivation layer from the bonding structure, removing an unnecessary component that increases fabrication complexity and cost. The direct bonding of conductive features without passivation layer reduces manufacturing steps and time while maintaining electrical connectivity through the UBM layer, conductive pillar, and solder bump structure.
Solution Approach 2:
The bonding structure is segmented into distinct functional layers: UBM layer for electrical connection, conductive pillar for structural support and additional connectivity, and solder bump for final bonding. This segmentation allows each layer to be optimized independently and facilitates a more efficient manufacturing process compared to traditional monolithic packaging approaches.
2Area of stationary object
If package size is reduced to increase integration density, then fewer materials and smaller area are used, but manufacturing precision requirements increase
Solution Approach 1:
The patent transitions from planar packaging to three-dimensional vertical stacking with conductive pillars extending upward from the UBM layer. This vertical dimensionality allows increased I/O connections and integration density without increasing the horizontal package area, while the standardized pillar dimensions maintain manufacturability.
Solution Approach 2:
The bonding structure employs nested layers where the UBM layer is embedded in the substrate, conductive pillars rise from the UBM layer, and solder bumps cap the pillars. This nested configuration maximizes connection density within a compact footprint while maintaining precise alignment through the hierarchical structure.
3Reliability
If passivation layer is added for protection, then conductive features are protected from environmental damage, but fabrication complexity and cost increase
Solution Approach 1:
The patent replaces the traditional passivation layer with a solder bump that serves both as a protective cap and as the bonding interface. The solder bump is a inexpensive, easily applied component that provides sufficient protection for the underlying conductive features while simplifying the overall structure and manufacturing process.
Solution Approach 2:
The solder bump serves multiple functions simultaneously: it protects the conductive pillar from environmental damage, provides the bonding interface for connecting to the substrate, and establishes electrical connectivity. This multi-functionality eliminates the need for separate passivation layers and reduces structural complexity.
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 allows for efficient bonding of semiconductor substrates with reduced fabrication costs and time, maintaining high integration density and functionality, and enabling smaller package structures with increased I/O connections.
Implementation Method 1
The first conductive feature is bonded to the second conductive feature through a bonding structure
Implementation Method 2
a solder bump
Data Source
AI summary
A package structure and a manufacturing method are provided. The package structure includes a semiconductor substrate and a first conductive feature over the semiconductor substrate. The package structure also includes a substrate and a second conductive feature over the substrate. The second conductive feature is bonded with the first conductive feature through a bonding structure. The package structure further includes a protection material surrounding the bonding structure, and the protection material is in direct contact with a side surface of the first conductive feature.