Space Transformer for Fine-Pitch Semiconductor Wafer Probing
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Solution Overview
Problem
The challenge in the semiconductor industry is to develop a space transformer that can effectively connect a signal source and probe highly integrated semiconductor wafers with fine testing pad pitches, as existing devices are limited in their ability to accommodate narrow pitches.
Innovation Solution
A space transformer is designed with a circuit board and a redistribution structure, where the redistribution structure has finer contact pads for probing the semiconductor wafer and a circuit board with coarser contact pads for connecting the signal source, both connected by conductive through vias to provide a vertical conductive path, allowing for efficient signal transmission and minimizing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single structure is used for both signal source connection and semiconductor probing, then device complexity is reduced, but the ability to accommodate both fine probe pitches and coarse signal connections is limited
Solution Approach 1:
The space transformer is divided into two distinct structures: a circuit board with coarse contact pads for signal source connection and a redistribution structure with fine contact pads for semiconductor probing. This segmentation allows each structure to be optimized for its specific function, enabling the device to accommodate both fine probe pitches and coarse signal connections simultaneously.
Solution Approach 2:
The patent transitions from a single-plane structure to a multi-dimensional configuration by stacking the redistribution structure onto the circuit board. This vertical arrangement allows fine-pitch probe contacts and coarse-pitch signal contacts to coexist in different spatial planes, resolving the pitch mismatch problem while maintaining structural organization.
2Manufacturing precision
If fine-pitch contact pads are used for both signal connection and probing, then probing capability is improved, but signal source connection becomes difficult
Solution Approach 1:
Different regions of the space transformer are assigned different contact pad characteristics: the redistribution structure has fine-pitch contact pads optimized for precise semiconductor probing, while the circuit board has coarse contact pads optimized for easy signal source connection. This local differentiation allows each interface to be optimized for its specific operational requirement.
3Adaptability or versatility
If signal transmission path is lengthened, then connection flexibility is improved, but signal noise increases
Solution Approach 1:
The conductive through vias act as intermediary vertical pathways that provide direct electrical connection between the circuit board and redistribution structure. This intermediary approach maintains signal integrity by providing short, direct transmission paths while still enabling the pitch transformation and connection flexibility between coarse and fine interfaces.
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 configuration enables the space transformer to meet the requirements of fine-pitch spacing for probing semiconductor wafers while ensuring reliable signal transmission to the probe side, improving signal performance and manufacturing efficiency.
Implementation Method 1
A circuit board is bonded to a redistribution structure through a bonding layer
Implementation Method 2
a conductive through via penetrating through the circuit board and providing a vertical conductive path between the circuit board and redistribution structure
Data Source
AI summary
A space transformer for connecting a signal source and probing a semiconductor wafer and a manufacturing method thereof are provided. The space transformer includes a circuit board, a redistribution structure bonded to the circuit board, and a conductive through via providing a vertical conductive path therebetween. The circuit board includes a wiring structure which includes alternately stacked dielectric layers and patterned wiring layers, and first contact pads of the patterned wiring layers connect the signal source. The redistribution structure is thinner than the circuit board and includes second contact pads for probing the semiconductor wafer. A pitch of adjacent second contact pads is finer than that of adjacent first contact pads. The conductive through via penetrates through the circuit board, and the conductive through via is laterally covered by the dielectric layers and is laterally and physically in contact with the patterned wiring layers.