Segmented Probe Card Stacking for High-Density Semiconductor Testing
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Solution Overview
Problem
The challenge lies in efficiently increasing the number of contact probes on a probe card to inspect all semiconductor chips on a large-area wafer within a single test process, while maintaining a manageable manufacturing process and aligning with existing electrode pitches, as current methods complicate the testing process and require extensive time.
Innovation Solution
The solution involves a probe card design with multiple unit plates of varying sizes, each with pad and contact probe areas, where the unit plates are laminated to expose all pad areas, and interconnected by conductive layers, allowing for a high-density arrangement of contact probes without reducing the electrode pad pitch, and a manufacturing method that forms these layers and assemblies to efficiently increase probe density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of contact probes is increased to test all semiconductor chips on a large-area wafer, then the productivity is improved, but the device complexity increases
Solution Approach 1:
The probe card is divided into multiple unit plates, each containing a subset of contact probes. This segmentation allows the system to achieve high productivity by combining multiple modular units, while each individual unit remains simple enough to manufacture and manage easily.
Solution Approach 2:
Unit plates are stacked in the thickness direction (z-axis) to arrange contact probes in three dimensions. This dimensional transition from 2D to 3D arrangement enables a significant increase in the number of contact probes without increasing the planar area, thereby improving productivity while maintaining manageable device complexity.
2Productivity
If contact probes are densely arranged to increase the number of probes, then the productivity is improved, but the manufacturing precision becomes more difficult to maintain
Solution Approach 1:
By dividing the probe card into multiple unit plates with standard pitch dimensions, the manufacturing precision requirement for each individual unit plate is reduced. This segmentation allows standard manufacturing processes to be applied to each unit while achieving high overall probe density through stacking.
Solution Approach 2:
The pitch between contact probes is optimized by utilizing the thickness direction for stacking unit plates. This parameter change in spatial arrangement allows maintaining standard pitch values in the planar direction while achieving high probe density through vertical stacking, thus balancing productivity and manufacturability.
3Quantity of substance
If the electrode pad pitch is reduced to accommodate more probes, then the quantity of contact probes is increased, but the manufacturing precision requirement increases
Solution Approach 1:
Instead of reducing the electrode pad pitch in the planar direction, the invention utilizes the thickness direction to stack multiple unit plates. This dimensional transition allows increasing the number of contact probes without compromising the electrode pad pitch, thereby maintaining manufacturing precision while achieving high probe quantity.
4Productivity
If a single large probe card is used to test all chips, then the productivity is improved, but the ease of manufacture decreases
Solution Approach 1:
The probe card is segmented into multiple unit plates that can be manufactured independently using standard processes. These modular units are then stacked and interconnected to form the complete high-density probe card, significantly improving ease of manufacture while achieving the productivity of a single large probe card.
Solution Approach 2:
Multiple unit plates are nested or stacked in the thickness direction, with each unit plate containing complete functional elements (contact probes, electrode pads, interconnecting layers). This nesting approach enables modular manufacturing of individual units followed by assembly, greatly simplifying the overall fabrication process while achieving high probe density.
Data Source
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AI summary
Provided is a probe card including a plurality of unit plates including pad areas and contact probe areas, a plurality of electrode pads formed in the pad areas, a plurality of contact probes formed in the contact probe areas, and a plurality of interconnecting layers electrically connecting the electrode pads and the contact probes. The plurality of unit plates has different sizes and are arranged and laminated so as to expose all the pad areas of each unit plate.