Probe Shunt Structure for High-Current Wafer Testing Reliability
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Solution Overview
Problem
Conventional wafer testing methods face issues such as probe burning, needle deformation, and reduced operational efficiency due to excessive current and metal fatigue caused by high-density chip designs, leading to unreliable test results.
Innovation Solution
A test device incorporating a guide plate structure with integrated shunt structures and probes that provide a shunt path for current redistribution when abnormalities occur, using insulation and metal areas within or between guide plates to manage excessive current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current (150 mA to 2A) is used for wafer testing, then testing capability is improved, but probe damage (burning, bending) occurs due to excessive current and metal fatigue
Solution Approach 1:
A shunt structure is introduced as an intermediary component between the probe and the device under test. This shunt structure provides an alternative current path that divides and redistributes the high testing current, preventing excessive current concentration in individual probes and thereby reducing probe damage while maintaining high-power testing capability
Solution Approach 2:
The current distribution parameters are changed by introducing the shunt structure. Instead of all current flowing through a single probe, the shunt structure modifies the current path to distribute current across multiple probes, changing the electrical parameters and reducing stress on individual probe elements
2Productivity
If multiple probes are used for high-density chip testing, then testing coverage is improved, but current concentration causes probe melting and deformation
Solution Approach 1:
The shunt structure serves as a mediator that intercepts and redistributes current from multiple probes. It provides alternative current paths that bypass damaged or overloaded probes, allowing the system to maintain high testing coverage while protecting individual probes from current-induced damage
Solution Approach 2:
The shunt structure is pre-configured to provide cushioning protection against current overload. By having alternative current paths ready in advance through the shunt structure, the system can absorb current shocks and prevent probe melting before damage occurs
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
Prevents probe damage and maintains test integrity by redirecting current through undamaged probes, thereby preventing melting and ensuring reliable electrical testing.
Implementation Method 1
the shunt structure contacts with a part of the plurality of probes to provide a current shunting route
Implementation Method 2
the stroke section is formed in a bent shape, and thus has functions of absorbing external forces and stroke
Implementation Method 3
the abnormal problems such as burning needles and bent needles may occurred due to instantly excessive current caused by electric heating (high temperature)
Data Source
AI summary
A test device including a guide plate structure, a shunt structure coupled to the guide plate structure, and a plurality of probes penetrating the guide plate structure and the shunt structure. A side of the guide plate structure is coupled to a circuit board, and another side is coupled to a device under test. The shunt structure has a metal material and thus can provide additional routes for the current, thereby melting caused by excessive current passing through due to abnormality of the probes per se can be prevented.