Probe Device Contact Resistance Reduction
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Solution Overview
Problem
Existing probe devices face challenges in maintaining high precision over time due to increasing contact resistance between metallic connection conductors and electrode plates, leading to reduced test accuracy in semiconductor wafer electrical testing.
Innovation Solution
The probe device incorporates contact probes with a gold-plated, electroless nickel-plated cable connection portion that is integrally formed with the contact portion, reducing electrical path length and eliminating the need for sliding units, along with a cleaning unit that maintains low contact resistance through brushing and polishing, ensuring consistent and precise electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic connection conductor makes contact with a metallic electrode plate to obtain electrical conduction, then electrical connection is achieved, but contact resistance increases over time due to metal pieces generated by contact
Solution Approach 1:
The patent replaces the mechanical sliding contact system with a spring-loaded contact probe system. The spring (13) provides constant elastic force to maintain stable contact between the contact probe (12) and the electrode plate (11), eliminating the need for sliding movements. This substitution of mechanical sliding with elastic contact resolves the issue of metal piece generation and contact resistance increase over time.
Solution Approach 2:
The patent changes the contact mechanism from sliding friction to elastic deformation. By using a spring-loaded probe that applies constant force, the contact parameters are optimized to maintain low contact resistance. The elastic force parameter of the spring ensures continuous stable contact without the wear and resistance increase associated with sliding contacts.
2Duration of action of stationary object
If a sliding unit is used to maintain contact between the connection conductor and electrode plate, then continuous electrical connection is achieved, but metal pieces are generated and contact resistance increases
Solution Approach 1:
The patent eliminates the sliding unit entirely and replaces it with a spring-loaded contact probe system. The spring (13) provides continuous contact pressure without sliding movements, thereby preventing metal piece generation. This mechanical substitution enables continuous operation while maintaining stable contact resistance and high reliability over extended periods.
Solution Approach 2:
The contact probe (12) with spring (13) is designed as a replaceable component that can be easily replaced when worn. This approach allows the main system to continue operating indefinitely by periodically replacing the consumable contact probe, achieving continuous operation while maintaining contact resistance stability.
3Adaptability or versatility
If the cable is made longer to accommodate the driving type mounting table, then the mounting table can be driven, but resistance and inductance of the cable increase
Solution Approach 1:
The patent extracts the electrical connection function from the mechanical driving system. By providing a separate metallic connection conductor (110) that is electrically connected to the conductive film electrode (101) and makes contact with the metallic electrode plate (11) at a location above the mounting table, the electrical connection path is shortened and separated from the mechanical cable routing required for driving the mounting table. This extraction reduces cable length and its associated resistance and inductance.
Solution Approach 2:
The metallic electrode plate (11) serves as an intermediary element that receives electrical connection from above the mounting table. This intermediary allows the electrical connection to be established at a location closer to the probes, reducing the effective cable length and electrical parasitics while still supporting the driven mounting table configuration.
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
This configuration significantly reduces contact resistance and inductance, allowing for precise and long-term high-precision testing of semiconductor devices by maintaining low electrical resistance and inductance, thereby enhancing the reliability of electrical characteristic measurements.
Implementation Method 1
a conductive film electrode made of a conductive metal such as gold is formed as a mounting table electrode at a mounting surface of a mounting table (chuck top) and the conductive film electrode makes contact with the electrode formed at the backside of the semiconductor wafer, thereby obtaining electrical conduction
Implementation Method 2
a cleaning unit that maintains low contact resistance through brushing and polishing
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A probe device includes an electrode plate arranged above a mounting table for mounting thereon a semiconductor wafer and electrically connected to a tester, a connection conductor arranged at a side of the mounting table and electrically connected to a mounting table electrode formed on a mounting surface of the mounting table, and a cleaning mechanism including a polishing unit for polishing a contact portion of the connection conductor, a brush cleaning unit for performing a brush-cleaning of the contact portion, and a contact resistance measuring unit for measuring a contact resistance of the contact portion. The mounting table electrode is in contact with a backside electrode of a semiconductor device of the semiconductor wafer. When the connection conductor is connected to the electrode plate, a backside electrode formed on a backside of the semiconductor device and the tester are electrically connected to each other.