Stacked Semiconductor Package Rear Structure for Fine-Pitch Integration
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Solution Overview
Problem
The challenge of achieving high integration and fine patterning in semiconductor devices, particularly in semiconductor packages, is hindered by the limitations in manufacturing processes that affect the spacing and connectivity of semiconductor chips.
Innovation Solution
A semiconductor package design that includes a first semiconductor chip with a rear protective layer and conductive pattern, a second semiconductor chip with specific pad regions, and chip interconnection terminals, along with an adhesive layer to enhance connectivity and spacing, allowing for efficient stacking and integration of multiple chips.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor chips are stacked with standard pitch spacing, then manufacturing is simpler, but integration density and bandwidth are limited
Solution Approach 1:
The patent transitions from standard planar pitch arrangements to a three-dimensional stacking architecture where chips are vertically positioned at different heights. The first chip is placed at a first height and the second chip at a second height, creating vertical separation that enables higher integration density without increasing lateral footprint. This dimensional change allows multiple chips to occupy the same lateral space while maintaining electrical isolation and signal integrity.
Solution Approach 2:
The patent divides the semiconductor package into distinct functional segments: a first chip with front and rear surfaces, a second chip stacked above it, adhesive layers for bonding, and encapsulant for protection. This segmentation allows each chip to be independently manufactured and tested before assembly, while the overall structure achieves high integration through vertical stacking. The rear surface of the first chip is specifically designed to accommodate the stacked configuration.
2Productivity
If chip spacing is reduced for high integration, then bandwidth increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent introduces adhesive layers as intermediary bonding materials between the first chip and second chip, and between chips and the encapsulant. These adhesive layers provide tolerance for alignment variations during manufacturing while ensuring reliable electrical and mechanical connections. The adhesive material compensates for minor positioning errors and enables precise chip placement without requiring extremely tight manufacturing tolerances.
Solution Approach 2:
The patent employs parameter changes in the form of different pitch values for different chip regions. The first chip has a first pitch for its front surface pads and a second pitch for its rear surface pads, allowing optimization of signal routing and connection density. This parameter variation enables high bandwidth communication while accommodating manufacturing capabilities through flexible pitch design.
3Productivity
If rear surface structures are added to chips, then connectivity and integration efficiency improve, but device complexity increases
Solution Approach 1:
The patent makes the chip rear surface multi-functional by incorporating both rear pads for electrical connection and a rear conductive pattern for signal routing. The rear surface serves dual purposes: providing mechanical support for the stacked configuration and enabling electrical connectivity to the second chip. This multi-functionality increases integration efficiency without proportionally increasing complexity, as the rear surface structures are integrated into the existing chip fabrication process.
Solution Approach 2:
The patent merges the rear pads and rear conductive pattern into a unified rear surface structure that simultaneously provides electrical connection and signal routing functions. The rear conductive pattern connects the rear pads to each other and to internal circuitry, combining multiple functions into a single integrated structure. This merging reduces the number of separate components and simplifies the overall chip design while achieving high integration efficiency.
Data Source
AI summary
A semiconductor package includes a plurality of chip interconnection terminals between a first semiconductor chip and a second semiconductor chip. The second semiconductor chip includes a test pad region between a first pad region and a second pad region. The first pad region includes a plurality of first front pads, the second pad region includes a plurality of second front pads, and the test pad region includes a test pad. The pads of the plurality of first front pads are spaced apart from each other by a first pitch, and a minimum distance between the plurality of first front pads and the plurality of second front pads is greater than the first pitch. At least a portion of the rear conductive pattern of the first semiconductor chip vertically overlaps the test pad.