Loop-back Probe Verification via Patterned Conductive Substrate
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Solution Overview
Problem
Current methods are inadequate for verifying the integrity and planarity of loop-back connections on integrated circuit probe cards, as they cannot be electrically tested using standard equipment, leading to reliance on manual and costly verification processes prone to human error.
Innovation Solution
A system and method that utilize a probe card analyzer with a semiconductor wafer or substrate patterned with metal contact dots, allowing for electrical continuity verification and planarity measurement of loop-back probes, using a reference mark and video imaging to calibrate and determine the position of the probes, and a force measurement device to assess contact resistance and planarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If loop-back probes are used to complete connections between two bonding pads, then circuit testing is enabled, but electrical verification of the probes becomes impossible
Solution Approach 1:
The patent introduces an intermediary conductive substrate with patterned contact regions that mediates between the loop-back probes and the probe card analyzer. This substrate provides a pathway for electrical verification by allowing the analyzer to contact the loop-back probes through the patterned conductive regions, thus resolving the contradiction between enabling circuit testing and allowing electrical verification.
Solution Approach 2:
The conductive substrate is segmented into multiple isolated conductive regions, each corresponding to specific probe contacts. This segmentation allows individual verification of each loop-back probe connection while maintaining the overall circuit testing capability, enabling both reliability and measurability.
2Measurement precision
If manual verification with Ohm meter is used, then connection integrity can be checked, but the process becomes slow and costly
Solution Approach 1:
The system enables automated self-verification where the probe card analyzer automatically contacts the loop-back probes through the patterned conductive regions and performs electrical verification without manual intervention. This eliminates the need for slow manual Ohm meter testing while maintaining measurement precision.
Solution Approach 2:
The patent replaces the manual mechanical process of using an Ohm meter with an automated electrical testing system. The probe card analyzer automatically performs electrical continuity and resistance measurements through the conductive substrate, substituting manual mechanical verification with automated electrical measurement to improve productivity.
3Manufacturing precision
If standard probe card analyzers are used, then alignment and planarity can be tested, but loop-back probe electrical connections cannot be verified
Solution Approach 1:
The conductive substrate serves multiple functions: it enables electrical verification of loop-back probes, maintains alignment references, and supports planarity testing. By integrating these functions into a single substrate, the system achieves versatility while maintaining manufacturing precision.
Solution Approach 2:
The patent adds a new dimension to probe card analysis by introducing a conductive substrate that provides electrical verification capability in addition to the existing mechanical alignment and planarity testing. This dimensional addition allows the analyzer to verify electrical connections without compromising its existing precision testing capabilities.
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 automated verification of loop-back connections and planarity, reducing human error and costs by providing a precise and efficient method for ensuring the correct electrical connections and positioning of loop-back probes.
Implementation Method 1
a video imaging device used by the probe card analyzer to determine the X,Y positions of the probes of an integrated circuit probe card
Implementation Method 2
a force measurement device to assess contact resistance and planarity
Implementation Method 3
measuring continuity between the substrate and the second conductive region
Implementation Method 4
measurement of actual contact resistance of a loop-back connection
Data Source
AI summary
A method is provided for using a loop-back test device to verify continuity between loop-back probes electrically connected to each other on a probe card, the loop-back test device including a first conductive region electrically connected to a substrate, a second conductive region electrically isolated from the substrate, the second conductive region spaced apart from the first conductive region such that when a first loop-back probe contacts the first conductive region a second loop-back probe contacts the second conductive region, The method includes placing the first loop-back probe in electrical contact with the first conductive region, and placing the second loop-back probe in electrical contact with the second conductive region. Continuity between the substrate and the second conductive region is then measured.