Probe Card Contact-Force Sensing for Needle Unbalance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing probe cards and methods for detecting their conditions are not entirely satisfactory, particularly in terms of efficiently and accurately determining probe card unbalance issues, which can affect the testing and validation of semiconductor wafers.
Innovation Solution
A probe card apparatus equipped with a pressure film sensor and a distance detector on a movable stage, allowing simultaneous contact with multiple needles to quickly detect contact forces and unbalance issues, and an adjustment driver to correct these issues by adjusting the support assembly based on detection results.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional probe card detection methods are used, then the detection process is simple, but the detection precision and ability to identify unbalance issues is insufficient
Solution Approach 1:
A force sensor is introduced as an intermediary component between the probe card needles and the support assembly. This mediator directly measures the contact force distribution, enabling precise detection of unbalance issues without requiring complex external measurement systems. The force sensor converts mechanical contact forces into measurable electrical signals, achieving high detection precision with relatively simple integration.
Solution Approach 2:
The patent replaces traditional mechanical observation or indirect measurement methods with direct force sensing technology. Instead of using complex mechanical gauges or visual inspection systems, the invention uses electronic force sensors to directly measure contact forces, substituting mechanical measurement systems with more precise electronic sensing and signal processing.
2Reliability
If probe card unbalance issues are not detected, then the testing process continues without interruption, but the reliability of wafer testing deteriorates
Solution Approach 1:
The force sensor is integrated into the support assembly structure, allowing contact force detection to occur automatically during the normal probing operation. The detection happens preliminarily and continuously as the probe card contacts the wafer, enabling early identification of unbalance issues before they affect testing reliability, without requiring separate detection steps that would consume additional time.
Solution Approach 2:
The system implements real-time feedback by continuously monitoring contact forces through the integrated force sensor. When unbalance is detected, the system can immediately signal for adjustment or stop the testing process, preventing reliability degradation. The feedback loop closes the gap between detection and corrective action, ensuring timely response to maintain testing reliability.
3Productivity
If multiple needles are contacted simultaneously for detection, then the detection speed increases, but the complexity of the detection apparatus increases
Solution Approach 1:
The force sensor is merged with the support assembly structure, combining the detection function with the existing mechanical support system. This integration allows multiple needles to be monitored simultaneously through a single unified sensing element or array, achieving high detection speed without proportionally increasing apparatus complexity. The merged design eliminates the need for separate detection mechanisms for each needle.
Solution Approach 2:
The force sensor serves multiple functions simultaneously: it supports the probe card structure, measures contact forces, and provides unbalance detection. This multi-functionality allows the same component to enable simultaneous monitoring of multiple needles without requiring additional specialized devices for each function, thereby increasing productivity without linearly increasing system complexity.
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
Enables rapid and precise detection of probe card unbalance, ensuring accurate testing of semiconductor wafers by balancing contact forces across the probe card needles, thereby improving the efficiency and reliability of wafer testing processes.
Implementation Method 1
detecting the contact force of the probe card via the pressure film sensor
Data Source
AI summary
A method for detecting a contact force of a probe card is provided. The method includes contacting a pressure film sensor with a plurality of needles over a lower surface of the probe card. The method includes detecting the contact force of the probe card via the pressure film sensor. The method also includes adjusting a position of a push base over an upper surface of the probe card based on the detected contact force of the pressure film sensor.