Grinding Apparatus for Small-Diameter Wafer Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing diameter of semiconductor wafers poses challenges in grinding technology, particularly for small-diameter wafers, as existing grinding apparatuses are not adequately designed to handle wafers with diameters of 13 mm or less efficiently.
Innovation Solution
A specialized grinding apparatus is developed, featuring a cassette system with a lid removal mechanism, vertical cassette table movement, wafer transfer and inverting mechanisms, a chuck table with suction for holding the wafer, and integrated grinding and cleaning systems, including a grinding wheel with abrasive members, water supply for grinding, and a two-fluid cleaning system using air and water mixtures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the wafer diameter is increased to 300 mm or 450 mm, then productivity in semiconductor device manufacture is improved, but the existing grinding apparatus is not adequately designed to handle small-diameter wafers (13 mm or less)
Solution Approach 1:
The apparatus employs dynamic adjustment mechanisms including a movable cassette table that can be vertically positioned, a chuck table that moves between standby and grinding areas, and a grinding wheel diameter adjustment system. These dynamic components enable the same apparatus to efficiently handle both small-diameter (13 mm) and large-diameter (300-450 mm) wafers by adapting the working space and positioning systems to match the wafer size being processed.
Solution Approach 2:
The grinding apparatus is designed with universal capabilities to process wafers of various diameters. The chuck table can hold wafers of different sizes, the grinding wheel can be adjusted to different diameters, and the cassette table can be vertically positioned to accommodate different wafer heights. This multi-functionality allows the apparatus to serve both small-diameter and large-diameter wafer grinding operations, eliminating the need for separate specialized equipment.
2Ease of operation
If a grinding apparatus is designed for large-diameter wafers, then it can handle 300 mm or 450 mm wafers, but it cannot efficiently process small-diameter wafers of 13 mm or less
Solution Approach 1:
The apparatus is divided into functionally independent segments: a cassette table for loading and storing wafers, a chuck table for holding and positioning wafers during processing, and a grinding wheel assembly. Each segment can be independently adjusted and controlled. The chuck table can be positioned independently to accommodate small wafers, while the grinding wheel can be adjusted to the appropriate diameter. This segmentation allows the system to handle small-diameter wafers efficiently without requiring a complete redesign of the entire apparatus.
Solution Approach 2:
The invention utilizes vertical dimensionality by implementing a movable cassette table that can be vertically positioned relative to the chuck table. This vertical adjustment capability allows the system to accommodate different wafer diameters and heights without increasing the horizontal footprint of the apparatus. The chuck table also moves between a standby area and a grinding area, creating dynamic spatial arrangements that optimize processing of small wafers while maintaining overall system compactness.
3Productivity
If the chuck table is positioned in the grinding area, then the wafer can be ground, but the wafer must be transferred from the standby area
Solution Approach 1:
The chuck table is pre-positioned in the standby area ready to receive wafers from the cassette table. The wafer transfer mechanism is pre-configured and ready to operate. When a wafer is loaded into the cassette table, the system can immediately begin the transfer process to the chuck table without requiring repositioning or readjustment. This preliminary preparation of the transfer system minimizes the time required to move wafers between the standby and grinding areas, thereby improving overall processing efficiency.
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 apparatus efficiently grinds small-diameter wafers to a desired thickness while maintaining a clean environment and recycling waste water to produce pure water for reuse, enhancing the processing of semiconductor devices.
Implementation Method 1
a chuck table for receiving the wafer inverted by the wafer inverting means in a wafer standby area and holding the wafer under suction
Implementation Method 2
grinding means provided in the grinding area for grinding the wafer held on the chuck table, the grinding means having a grinding wheel composed of a wheel base and a plurality of abrasive members annularly mounted on the wheel base
Implementation Method 3
a cleaning water nozzle provided inside the dome for spraying a cleaning water toward the wafer
Implementation Method 4
the cleaning water supplied by the cleaning water supplying means is mixed with the air supplied by the air supplying means to form a two-fluid mixture, which is sprayed from the cleaning water nozzle
Data Source
AI summary
A grinding apparatus for grinding a wafer stored in a cassette composed of a container for storing the wafer and a lid for enclosing the container. The grinding apparatus includes a cassette table for placing the cassette thereon, a lid removing unit for removing the lid from the cassette placed on the cassette table and leaving only the container on the cassette table, a chuck table for holding the wafer under suction, a chuck table moving unit for moving the chuck table to a grinding area, a grinding unit provided in the grinding area, the grinding unit having a grinding wheel for grinding the wafer held on the chuck table, a grinding water supplying unit for supplying a grinding water to abrasive members of the grinding wheel, and a waste water collecting unit for collecting waste water generated in grinding the wafer by operating the grinding unit.