Probe Apparatus Attracting Device Segmentation
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Solution Overview
Problem
Conventional probe apparatuses for inspecting power devices with electrodes on both sides of a semiconductor wafer at wafer level face high and non-uniform wafer contact resistance, leading to poor measurement accuracy and reproducibility due to high impedance in the measurement lines.
Innovation Solution
A probe apparatus with an attracting device featuring many vertical fine holes in a specific pattern (diameter φ and pitch p) where φ < p ≤ 2φ, significantly reducing and uniformizing the contact resistance between the rear surface electrode and the mounting surface conductor, thereby improving measurement accuracy and power consumption efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional groove type or hole type attracting devices are used, then the wafer can be held at a certain position on the chuck top, but high and non-uniform contact resistance occurs between the rear surface electrode and mounting surface conductor
Solution Approach 1:
The attracting device is segmented into multiple fine holes (300-400 holes) distributed across the mounting surface, replacing the conventional few grooves or holes. This segmentation increases the number of contact points between the wafer and mounting surface conductor, distributing the electrical contact across multiple locations to reduce overall contact resistance and improve uniformity.
Solution Approach 2:
The invention creates locally optimized contact regions by forming fine holes with specific dimensions (diameter 0.3-0.7mm, pitch 1.5-3.0mm) that provide both mechanical holding and electrical contact functions. Each hole acts as a localized contact point with optimized geometry to ensure low contact resistance while maintaining position holding capability.
2Reliability
If conventional groove type or hole type attracting devices are used, then the wafer can be held at a certain position on the chuck top, but high impedance in measurement lines results in poor reproducibility
Solution Approach 1:
The attracting device is segmented into multiple fine holes (300-400 holes) distributed across the mounting surface, replacing the conventional few grooves or holes. This segmentation increases the number of contact points between the wafer and mounting surface conductor, distributing the electrical contact across multiple locations to reduce overall contact resistance and improve uniformity.
Solution Approach 2:
The invention changes the geometric parameters of the attracting device features: hole diameter is reduced to 0.3-0.7mm (compared to conventional larger grooves/holes), and hole density is increased to 300-400 holes. These parameter changes optimize both the mechanical holding force and the electrical contact quality, reducing contact resistance to 10mΩ or less.
3Device complexity
If fewer suction grooves or holes are used, then the attracting device structure is simpler, but contact resistance increases and becomes non-uniform
Solution Approach 1:
The attracting device is segmented into multiple fine holes (300-400 holes) distributed across the mounting surface, replacing the conventional few grooves or holes. This segmentation increases the number of contact points between the wafer and mounting surface conductor, distributing the electrical contact across multiple locations to reduce overall contact resistance and improve uniformity.
Solution Approach 2:
The invention changes the geometric parameters of the attracting device features: hole diameter is reduced to 0.3-0.7mm (compared to conventional larger grooves/holes), and hole density is increased to 300-400 holes. These parameter changes optimize both the mechanical holding force and the electrical contact quality, reducing contact resistance to 10mΩ or less.
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 effectively reduces and uniformizes the contact resistance, enhancing measurement accuracy and power consumption efficiency by minimizing impedance in the measurement lines, allowing for more precise inspection of electrical characteristics of power devices.
Implementation Method 1
a vacuum evacuation type attracting device has been used
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A probe apparatus of inspecting electrical characteristics of a power device having electrodes on both sides of a substrate at wafer level can reduce and uniformize a contact resistance between the electrode on a rear surface of the substrate and a mounting surface conductor of a chuck top. In the probe apparatus, an attracting device supports a semiconductor wafer W on the chuck top 12, and has many vertical fine holes in a pattern (diameter φ and pitch p) that satisfies the condition of φ < p ≤ 2φ. For example, the diameter φ is about 0.25 mm, and the pitch p is about 0.5 mm.