Browse Prior Art Database

Airlock Mechanism for Loading/ Unloading Greensheets

IP.com Disclosure Number: IPCOM000121748D
Original Publication Date: 1991-Sep-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 3 page(s) / 103K

Publishing Venue

IBM

Related People

Brown, ME: AUTHOR [+2]

Abstract

Described is a vacuum airlock mechanism for loading and unloading greensheet circuit boards into an electron beam (E-beam) drilling chamber. The airlock mechanism enables the greensheet loading/ unloading process to proceed automatically. This eliminates the need for the main vacuum chamber to be pumped down each time a part is processed.

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Airlock Mechanism for Loading/ Unloading Greensheets

      Described is a vacuum airlock mechanism for loading and
unloading greensheet circuit boards into an electron beam (E-beam)
drilling chamber.  The airlock mechanism enables the greensheet
loading/ unloading process to proceed automatically.  This eliminates
the need for the main vacuum chamber to be pumped down each time a
part is processed.

      In prior art, the E-beam drilling chamber used to drill holes
in the greensheet circuit boards necessitated manual evacuation and
repressurization cycles each time a greensheet was loaded and
unloaded.  The concept described herein provides an airlock mechanism
that eliminates the previously required evacuation/repressurization
cycles.  The mechanism allows an exchange between vacuum and
atmosphere that provides a dual-position part-holding queue.

      The airlock mechanism is shown in the figures.  Fig. 1a is the
top view, Fig. 1b is the front view and Fig. 1c is the upper 45~
angle view of the mechanism.  Fig. 2a is a sectional view across A-A
of Fig. 1b.  Fig. 2b is a sectional view across B-B of Fig. 2a.  Fig.
2c is a sectional view across C-C of Fig. 2a, and Fig. 2d is an
enlarged detail view of detail D of Fig. 2b.

      At the start of a machine-loading operation, chamber 18 (Fig.
1a) is at vacuum.  Large gate valve 4 is closed and small gate valve
3 is open. This enables airlock 1 to be at ambient pressure.  Shuttle
arm 13 (Figs. 1a, 2a and 2c) is up and loaded with carrier 5.  Rotary
arm 14 is at its lower home position.  Shuttle arm 13 extends into
upper airlock 1 position.  Carrier 5 is lifte...