Proximity Sensor for Load Cup Substrate Detection
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Solution Overview
Problem
Existing load cup systems in CMP systems face premature sensor failure due to fluid penetration and other factors, leading to increased maintenance costs and reduced operational reliability.
Innovation Solution
The implementation of non-contacting proximity sensors with detection pads and movable targets on lever members within the load cup assembly, which eliminate the risk of water infiltration and provide reliable substrate presence detection without increasing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional contact sensors are used to detect substrate presence, then the sensing function is achieved, but the sensor lifespan is reduced due to fluid penetration and premature failure
Solution Approach 1:
The patent replaces traditional mechanical contact sensors with a non-contact sensing system consisting of a capacitive sensor and a target element. The capacitive sensor detects substrate presence through electrical field interaction without physical contact, eliminating mechanical wear and fluid infiltration issues while maintaining reliable detection functionality.
2Reliability
If non-contacting proximity sensors are implemented, then sensor reliability is improved by preventing fluid ingress, but device complexity increases
Solution Approach 1:
The load cup assembly integrates multiple functions into existing components: the capacitive sensor serves both as a presence detector and a fluid barrier, the target element on the lever member provides both mechanical leverage for substrate engagement and an electrical target for capacitive sensing, and the lever member itself functions as both a mechanical actuator and a mounting structure for the target element.
3Duration of action of stationary object
If sensors are protected from fluid penetration, then sensor lifespan is extended, but manufacturing cost may increase
Solution Approach 1:
The capacitive sensor inherently provides its own protection by being positioned within the load cup assembly structure and detecting substrates through non-contact electrical field interaction. The sensor does not require separate protective housings, seals, or maintenance interventions, as its operating principle naturally prevents fluid infiltration while enabling continuous operation.
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 solution significantly extends sensor lifespan by preventing fluid ingress and ensuring consistent detection of substrate presence, enhancing the reliability and cost-effectiveness of the CMP system.
Implementation Method 1
a proximity sensor having a detection pad disposed below a contact surface of a load cup assembly
Data Source
AI summary
Methods, apparatus, and systems are provided for detecting the presence of a substrate in a load cup. The invention includes a proximity sensor having a detection pad disposed below a contact surface of a load cup assembly and a target disposed on a lever member and adapted to move toward the detection pad when a substrate is placed on the lever member and adapted to move away from the detection pad when a substrate is removed from the lever member. Numerous additional aspects are disclosed.