Probe Card Parallelism Control via Laser Reference and Camera
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for adjusting the parallelism between a probe card and a mounting table in probe apparatuses are complex, requiring high skill levels and significant time, and do not effectively ensure proper contact between probe pins and a wafer, leading to unreliable inspections and potential damage.
Innovation Solution
A method involving the selection of probe pins at distinct locations, detection of their tip positions, calculation of imaginary probe pin positions, and adjustment of the probe card's parallelism with the mounting table based on these coordinates, using a storage medium with an inspection program to automate the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods for adjusting parallelism are used, then the parallelism between probe card and mounting table can be adjusted, but the adjustment process is complex and requires high skill level and significant time
Solution Approach 1:
The patent replaces complex mechanical adjustment systems with an optical measurement system. A laser beam is used to project a reference line on the mounting table, and a camera captures the positions of probe pins relative to this line. The control unit automatically calculates and adjusts parallelism based on these optical measurements, eliminating the need for complex mechanical gauges and manual adjustment procedures.
Solution Approach 2:
The system enables automatic self-adjustment of parallelism. The control unit receives position information from the camera, automatically calculates the parallelism deviation, and controls the driving unit to adjust the probe card position. This closed-loop automatic control eliminates the need for operator skill and manual intervention in the adjustment process.
2Manufacturing precision
If manual adjustment methods are used, then parallelism can be controlled, but the adjustment time is significant and productivity is reduced
Solution Approach 1:
The system performs preliminary automatic adjustment of parallelism before the actual inspection process. By using the laser reference line and camera to pre-measure and pre-adjust the probe card position, the system ensures optimal parallelism is achieved automatically, eliminating time-consuming manual adjustments during production and increasing overall throughput.
Solution Approach 2:
The patent implements a feedback control mechanism where the camera continuously monitors probe pin positions relative to the laser reference line, and the control unit uses this feedback to automatically adjust the probe card position. This real-time feedback loop ensures rapid convergence to the optimal parallelism setting, significantly reducing adjustment time compared to manual methods.
3Productivity
If improper parallelism exists between probe card and wafer, then inspection can still be performed, but the inspection reliability deteriorates and damage may occur
Solution Approach 1:
The system takes preliminary action to prevent improper parallelism before inspection begins. By using the laser reference line and camera to measure and adjust the probe card position in advance, the system ensures that optimal parallelism is achieved before any inspection occurs, preventing potential damage and ensuring high inspection reliability from the start.
Data Source
AI summary
In a method for controlling a parallelism between a probe card having a number of probe pins and a mounting table, first, among the probe pins, one or more probe pins corresponding to each of plural distinct locations on an X-Y coordinate system whose origin lies at a probe center are selected. Then, a tip of each of the selected probe pins is detected to obtain position coordinates (X,Y,Z) thereof. Thereafter, a specific point on each of connection lines connecting tips of neighboring selected probe pins is selected and their position coordinates on the connection lines are calculated, wherein the position coordinates of the specific points are set as position coordinates (X,Y,Z) of tips of imaginary probe pins. Subsequently, the parallelism between the probe card and the mounting table based on the position coordinates (X,Y,Z) of the tips of the imaginary probe pins is adjusted.