Probe Card Circuit Switch Modules for Fault Isolation
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Solution Overview
Problem
Conventional probe card circuits fail to test multiple semiconductor chips effectively when one chip is damaged, leading to short circuits that disrupt the testing of other chips.
Innovation Solution
Incorporating switch modules with transistors and amplifiers in the probe card circuit, allowing selective transmission of test response signals from damaged chips, ensuring uninterrupted testing of remaining chips by floating probes based on test power status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional probe card circuit is used to test multiple chips simultaneously, then testing efficiency is improved, but a short circuit in one chip disrupts testing of all other chips
Solution Approach 1:
The probe card circuit is segmented into multiple independent test channels, each with its own switch module. This segmentation isolates faults to individual channels, preventing a short circuit in one chip from affecting other channels. Each channel can independently control its probe connections through dedicated switch modules, allowing continuous testing of healthy chips even when one channel experiences a short circuit.
2Measurement precision
If all probes are connected to transmit test signals, then comprehensive testing is achieved, but short circuits cause signal interference and testing failure
Solution Approach 1:
The probe card employs dynamic control of probe connections through switch modules that can change connection states based on test conditions. The switch modules dynamically connect or disconnect probes from the signal line, allowing the system to adapt to different testing scenarios. This dynamic control enables selective isolation of probes experiencing short circuits while maintaining connections for healthy chips, thereby preventing signal interference and preserving test signal accuracy.
3Device complexity
If simple probe card circuit is used, then device complexity is reduced, but fault isolation and continued testing capability are lost
Solution Approach 1:
The switch modules serve multiple functions: they control probe connections to selected chips, isolate short circuits, and enable continued testing of healthy chips. This multi-functionality is achieved through a relatively simple switch module design that integrates connection control and fault isolation capabilities. The universal application of switch modules across all test channels provides fault tolerance without requiring complex specialized circuits for each function.
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 simultaneous testing of multiple chips even if one is short-circuited, preventing disruption and allowing all chips to be evaluated without discarding healthy ones.
Implementation Method 1
each of the switch modules may further include a transistor having a first source/drain end coupled to the test unit, a second source/drain end for receiving the test response signal, and a gate end for receiving a test power
Implementation Method 2
The amplifier has an input end for receiving the test power and an output end coupled to the gate end of the transistor
Data Source
AI summary
A circuit in probe card, which includes a signal line, a detection probe and a plurality of switch modules. A plurality of test response signals form a plurality of chips to be tested are transmitted on the signal line. The detection probe is coupled to the signal line for receiving the test response signals from the tested chips. In addition, each of the switch modules is respectively coupled to the signal line and the probes to selectively transmit the test response signals from the chips to the signal line such that the chips are able to be tested without disruption caused by an electrical short.