for$worksafety$at$the$vicinity$ of$$overheadtransportaon vehicle$systems...

For Work Safety at the Vicinity of Overhead Transporta8on

Vehicle Systems

Shigehito Ibuka Tokyo Electron Limited

May 19, 2011 @IHTESH2011, Arizona, USA

Outlines

•  Pictures of “Overhead Transporta8on Vehicles” •  Background •  Case Study of some Incidents

•  SEMI Workshop – Risk – Engineering Control – Administra8ve Control

– Summary

3

Pictures of Overhead Transporta8on Vehicles

OHT OHS

•  Huge semiconductor fab •  High produc5vity demand

Background

Unmanned transportation vehicle system (UTV), Especially, Overhead transportation vehicle system (OHV / OHT)

Automation

•  High speed •  More than 100 vehicles in a fab

Start-‐up or maintenance work on semiconductor manufacturing tools

•  Collision •  Near-miss How to prevent?

•  When a person climbed the ladder to do wiring work on the system carrier stage, he turned to face the system and was struck on the shoulder by an OHV running from his right.

Case Study: Ver8cal Furnace

TEL system

Sub-frame

Non-TEL system

OHT (overhead hoist transport) collision 1 collision 2

OHT was stopped about 10 m away from the system, but suddenly started moving.

•  The sub-frame was pushed and hit the worker opposite the collision in the head. The injured person got his head caught between the system behind him and the sub-frame.

•  Fortunately, the injured person was wearing a helmet and did not fall off the ladder, so he avoided injury.

•  At mounting a sub-frame on top of a system, an OHV suddenly moved and collided with the sub frame that was being mounted.

Case Study: Wet Cleaning System

TEL System

Other System

T Block ２

CSB

OHV

A ladder

•  A person had known that a ladder set in front of the system was a hindrance to the work and temporarily moved the ladder to the CSB side.

•  Immediately after moving the ladder, he determined that his help was needed to support other work and he left the area without confirming appropriate position of the ladder.

•  At that point, the OHV struck the ladder, causing the OHT cover to break.

Case Study: Coater and Developer

SEMI Safety Workshop

Held in SEMICON Japan 2010

Cited from materials used in the Workshop

Position of Semiconductor Manufacturing Equipment and OHT （The numerical value is one example. ）

OHT OHT

3500mm（SEMI E72 Max）

2800mm

2700～3000mm

1500mm/sec

3000mm/sec

FOUP

OHT OHT

Potential Hazard and Risk Estimation

Risk Estimation Severity:1, Likelihood：C ---> Risk Rank：Ⅳ（High）

OHT OHT

Risk Estimation Severity:1, Likelihood：C ---> Risk Rank：Ⅳ（High）


OHT OHT

Risk Estimation Severity:1, Likelihood：C ----> Risk Rank：Ⅳ（High）


Risk Estimation Severity:2, Likelihood：C ----> Risk Rank：Ⅲ（Medium）

OHT OHT


OHT OHT

Risk Estimation Severity:3, Likelihood：C ----> Risk Rank：Ⅱ（Low）


Position tracking by

sensor

OHT OHT

Prevention interlock

between worker and FOUP

I/F based on SEMI E84

Interlock between SME

and OHT

Collision prevention means with

OHT

Partition or Defense

equipment

Examples of Engineering Controls

An Example of Engineering Controls

Obstacle sensor function

Obstacle Sensor Detection Area

＊Obstacle Sensor Detection Area (straight)

detection1 detection2

stop Slowdown

1.  Conduct Job Hazard Analysis (JHA) {Work Risk Assessment or Pre-task Planning (PTP)}   Refer to SEMI S21

2.  Request the user of a fab to have the vehicle stop before entry in the OHT area

3.  Share hazard or risk information among personnel of multiple suppliers and contractors to work in the adjacent area simultaneously   Hold "Safety Supervisors’ Communication Council" among the

user, multiple suppliers and contractors --- Refer to SEMI S24   Conduct joint “Safety patrol” --- Refer to SEMI S24

4.  Conduct safety training for all workers   Refer to SEMI S19

Examples of Administrative Controls

An Example of Administrative Controls

Elevated W

ork

Stop by front sensor

Detection Board Board Setting

Summary of the Workshop

Comments / Suggestions after the Workshop •  Shared what are issues for tool & vehicle suppliers •  To plan how to share the issues with Asian IDMs and how to

improve work environment in a fab •  More cases and experiences to be shared •  To consider how to utilize a protection board set on the OHV

rail protect •  Importance of SEMI S17 understood •  Torque of OHV to be recognized among users & tool suppliers •  To consider engineering controls such as sensor or some

ideas to utilized by public train systems •  To specify roles of users & suppliers and share them among

concerned entities •  To consider hooking points on the OHV run-yard •  To hold similar concept workshops globally

Thank you for your aTen8on!

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