Mercury Probe Apparatus Pneumatic Mercury Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for measuring electrical properties of semiconductor wafers using a mercury column are hazardous due to mercury toxicity and contamination, requiring frequent manual replacement and posing risks of mercury spillage.
Innovation Solution
A mercury probe apparatus with a capillary tube and pneumatic control system that minimizes mercury exposure and spillage by using a small mercury volume within the capillary tube, automatic mercury change mechanism, and a mercury containment unit with separate clean and contaminated mercury containers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a large mercury reservoir (1-2 cm³) is used, then the time between mercury replacements is extended, but the risk of mercury spillage and the danger to health and environment increases
Solution Approach 1:
The mercury reservoir is divided into two separate containers: a clean mercury container and a contaminated mercury container. This segmentation allows the system to maintain a small total mercury volume while extending the time between replacements by transferring mercury from the clean container to the capillary tube, thereby reducing spillage risk through minimized mercury quantity in each container.
Solution Approach 2:
The contaminated mercury container is nested inside the clean mercury container. This nested arrangement allows the system to hold both clean and contaminated mercury in a compact configuration, maintaining small total mercury volume while enabling automatic transfer operations that extend replacement intervals and reduce spillage hazards.
2Device complexity
If manual mercury replacement is performed, then the apparatus can be simpler in structure, but the operation becomes time-consuming, dangerous, and requires specially trained personnel
Solution Approach 1:
The apparatus performs mercury replacement automatically through a pneumatic system that transfers mercury from the clean container to the capillary tube without human intervention. The system self-regulates the mercury transfer process, eliminating the need for trained personnel to handle mercury manually, reducing time consumption, and maintaining safety while requiring only basic container replacement operations.
Solution Approach 2:
The manual mechanical operation of mercury replacement is replaced by an automated pneumatic system. The pneumatic pressure control system automatically transfers mercury from the clean container to the capillary tube, eliminating the need for manual handling and reducing operational complexity and safety risks.
3Productivity
If periodic cleaning of mercury is implemented, then the frequency of mercury replacement is reduced, but the cleaning process adds complexity and some contaminants cannot be perfectly removed
Solution Approach 1:
Instead of attempting to clean and reuse contaminated mercury, the system extracts the contaminated mercury into a separate container and replaces it with fresh mercury from the clean container. This extraction approach eliminates the need for complex cleaning mechanisms while maintaining high measurement throughput by ensuring always-fresh mercury for measurements.
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 enhances safety by reducing mercury exposure and spillage risks, automating the mercury change process, and extending the time between mercury replacements without compromising measurement accuracy.
Implementation Method 1
a fluid connection for selectively producing partial vacuum or ambient pressure within the capillary tube for drawing up a mercury into the capillary tube, holding it, and releasing it
Implementation Method 2
The probe head comprises a base 20 fixed to the probe arm 1, a capillary tube 21 that is preferably made of a dielectric material
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The disclosure relates to an apparatus for measuring electrical properties of a semiconductor wafer (W). The apparatus comprises a wafer holder (3), a probe head for contacting the top surface of said wafer (W) with a mercury column (M), wherein the probe head includes a capillary tube (21) for containing said mercury column (M). The apparatus further comprises a pneumatic control means (23) for applying a partial vacuum or pressure above said mercury column (M) within said capillary tube (21), a probe arm (1) having said probe head affixed thereto, a positioning means for controlling the position of said capillary tube (21) relative to the upper surface of said wafer (W), a measurement means for causing an electrical current to flow through said wafer and for measuring electrical properties of said wafer, a first electrical contact (24) electrically connected to said mercury column (M) and to said measurement means, a second electrical contact electrically connected to said wafer holder (3) and said measurement means, a clean mercury container (41), and a control unit in operating connection with the pneumatic control means (23), the positioning means and the measurement means. Furthermore, the probe head has at least one measurement position and a first mercury change position, wherein the capillary tube (21) is separated from the clean mercury container (41) in said at least one measurement position and in fluid communication with the clean mercury container (41) in said first mercury change position.