Dual-Arm FOUP Handler Layout for Continuous Wafer Transfer

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Solution Overview

Problem

In vertical batch furnace assemblies, the wafer handler often remains idle during the transfer of multiple wafer cassettes, leading to inefficiencies as the cassette handler cannot transfer wafers and cassettes simultaneously, resulting in idle times that detract from the assembly's capacity.

Innovation Solution

A vertical batch furnace assembly design featuring a cassette handling space with a cassette handler comprising two arms and an elevator mechanism, allowing simultaneous transfer of wafer cassettes between storage and the wafer transfer position, enabling the wafer handler to load/unload wafers without waiting for cassette transfers to complete.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single cassette handler transfers wafer cassettes sequentially, then the structure remains simple, but the wafer handler remains idle during cassette transfers, reducing overall productivity

Engineering Contradiction:

Improveoverall assembly capacityVSAvoidcassette handler structure

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The cassette handler is divided into two independent arms (first and second cassette handler arms), each capable of transferring cassettes independently. This segmentation allows parallel operations where one arm transfers a cassette while the other arm or the wafer handler performs different tasks, eliminating idle time and improving overall productivity without requiring a completely new system architecture

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first cassette handler arm transfers a first wafer cassette to the wafer transfer position in advance, allowing the wafer handler to begin loading or unloading wafers before the second cassette is transferred. This preliminary action ensures that the wafer handler never remains idle, as cassette transfers and wafer operations are overlapped in time

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the wafer handler waits for cassette transfers to complete, then operational simplicity is maintained, but idle time increases, reducing efficiency

Engineering Contradiction:

Improvewafer handler utilizationVSAvoididle time during transfers

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The dual-arm cassette handler enables continuous useful action by overlapping cassette transfer operations with wafer loading/unloading operations. While the first cassette handler arm transfers a cassette, the wafer handler simultaneously loads or unloads wafers from another cassette. This eliminates idle waiting time and ensures that the wafer handler is continuously productive throughout the entire cycle

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

Cassette transfers are performed in advance of when the wafers are needed. The first cassette handler arm transfers a first wafer cassette to the wafer transfer position before the wafer handler needs to access it, allowing the wafer handler to immediately begin work without waiting for the transfer to complete

Inventive Principle:

Principle #10Preliminary action

3Productivity

If multiple cassettes are transferred sequentially through a single handler, then system complexity is minimized, but the transfer time increases, reducing throughput

Engineering Contradiction:

Improvecassette transfer rateVSAvoidtotal transfer time

Core Design Contradiction:

ProductivityVSDuration of action of moving object

Solution Approach 1:

The cassette transfer function is segmented into two independent arms that can operate simultaneously or in coordinated sequence. This allows multiple cassettes to be transferred in parallel rather than strictly sequentially, reducing the total transfer time while maintaining manageable system complexity through modular arm design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The first cassette handler arm performs preliminary transfers of cassettes to the wafer transfer position before they are needed for wafer loading/unloading. This advance preparation reduces the total time required for the complete cycle by overlapping transfer operations with processing operations

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11798830B2Fast FOUP swapping with a FOUP handler

Publication Date: 2023.10.24 ASM IP HLDG BV

AI summary

A vertical batch furnace assembly for processing wafers having a cassette handling space, a wafer handling space, and a first wall and separating the cassette handling space from the wafer handling space. The first wall has at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided. The cassette handling space comprises a cassette storage having a plurality of cassette storage positions and a cassette handler configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position. The cassette handler has a first cassette handler arm and a second cassette handler arm.