Mechanism using a helix sequentially feeds prescribed amounts of metal charges into an evaporation boat used for flash vapor deposition of the evaporants onto a substrate in a vacuum chamber. The helix is advanced by external manual controls extending through sealed feed- through devices into the chamber wall

Hermann, W. A.

Stirn, R. J.

English

NASA Technical Reports Server

September 1967	 Brief 67-10320 
NASA TECH BRIEF 
VIM	 7 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Evaporant Feed Device Facilitates Flash Vapor Deposition Process in Vacuum 
Quartz Crystal Microbalance 
Shutter
Helix 
1,pI 
Metal	 •I.  
Tungsten 
Evaporation 
Boat 
I, 
,l	 Evaporation 
/	 Shield	 d 
Copper Bus	 - (Nickel)
Ball Chain
To Rotary 
Feed-Through 
The problem: 
To devise a mechanism that will sequentially feed 
prescribed amounts of metal charges (evaporants) into 
an evaporation boat used for flash vapor deposition of 
the evaporants onto a substrate in a vacuum chamber. 
Sequential feeding and flashing of the evaporants, 
which may consist of several types of metals, must be 
accomplished without opening the vacuum chamber 
or moving the substrate during the deposition process.
The solution: 
A mechanism employing a helix that is advanced by 
external manual controls, extending through sealed 
feed-through devices into the chamber wall, to feed 
the desired metal evaporant into the evaporation boat. 
The evaporants are made in the form of rings of 
specified dimensions, according to the desired thick-
ness of metal (metals) to be deposited onto the sub-
strate. 
All
(continued overleaf) 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19670000320 2020-03-11T20:40:36+00:00Z
How it's done: 
Before beginning a deposition operation, the 
evaporant rings are spaced at prescribed intervals on 
the loading wire. Stop pins are used for repositioning 
the loading wire in a reproducible manner. The sub-
strate and quartz crystal microbalance (used to weigh 
the deposited metal) are supported over the evapora-
tion boat. 
In carrying out a deposition in the evacuated cham-
ber, electrical power is switched to the bus bar to heat 
the evaporation boat to operating temperature. The 
helix is then advanced by means of the ball-chain 
linkage until the first evaporant ring slips down the 
loading wire into the evaporation boat. The position 
of the shutter is set so that the substrate and micro-
balance are unshielded when the metal ring strikes the 
hot evaporation boat. At other times, the quartz 
crystal microbalance is shielded in order to mini-
mize heating effects. After one flash evaporation is 
completed, additional evaporations are carried out by 
sequentially feeding the metal rings into the evapora-
tion boat in a similar manner. 
Note: 
Inquiries concerning this innovation may be di-
rected to:
Technology Utilization Officer 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Reference: B67-10320 
Patent status: 
No patent action is contemplated by NASA. 
Source: Dr. R. J. Stirn and W. A. Hermann 
of Jet Propulsion Laboratory 
(N P0-10232)
. 
Brief 67-10320	 Category 03


Evaporant feed device facilitates flash vapor deposition process in vacuum

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