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Browse Prior Art Database

Portable Dynamic Pressure-Sensing Apparatus

IP.com Disclosure Number: IPCOM000039162D
Original Publication Date: 1987-Apr-01
Included in the Prior Art Database: 2005-Feb-01
Document File: 2 page(s) / 105K

Publishing Venue

IBM

Related People

Krysty, S: AUTHOR [+2]

Abstract

This article concerns the development of a portable pressure-sensing equipment employable as a standard in the measurement and calibration of double-sided wafer polishers. It offers a capability for measuring the actual pressure exerted on a wafer throughout the total polishing cycle, in a dynamic mode, and can be used as a standard for all polishers. (Image Omitted) Frictional variations inherent in the design of existing wafer polishers lead to a lack of process reproducibility when programmed changes in wafer pressure are called for. The disclosed pressure sensing assembly, comprising three load cells (strain gage) contained between two thrust bearings (radial bearings), is illustrated in Fig. 1.

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Portable Dynamic Pressure-Sensing Apparatus

This article concerns the development of a portable pressure-sensing equipment employable as a standard in the measurement and calibration of double-sided wafer polishers. It offers a capability for measuring the actual pressure exerted on a wafer throughout the total polishing cycle, in a dynamic mode, and can be used as a standard for all polishers.

(Image Omitted)

Frictional variations inherent in the design of existing wafer polishers lead to a lack of process reproducibility when programmed changes in wafer pressure are called for. The disclosed pressure sensing assembly, comprising three load cells (strain gage) contained between two thrust bearings (radial bearings), is illustrated in Fig. 1. This assembly is placed between the two platens of the polisher, and permits running the pressure cycle without deactivating the platen rotation motors, thus bypassing a major source of the present measurement error encountered in determining the load between the two platen surfaces. Fig. 3 shows the upper and lower polishing platens 1 and 2 which are removed and replaced with the disclosed sensing apparatus 3 and 4, as shown in Fig. 2. The upper assembly 3 is held in position with four socket head screws 5, and lower assembly 4 is placed over the two drive pins 6. As shown in Fig. 2, the upper assembly consists of an upper rotator 7, a radial bearing 8, four holders 9, a stationary plate 10, and two pinlocks 12. The lower a...