Semiconductor package has been developed for high power semiconductor devices that operate in the GHz-frequency range at several watts. Package includes stud, insulating ring, electrically conductive washer, insulating washer, braze ring, and cap. It is mechanically strong and can be used with variety of circuits

Jacobson, D. S.

English

NASA Technical Reports Server

December 1973	 B7340427 
•	 NASA TECH BRIEF 
Goddard Space Flight Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Hermetic-Coaxial Package Design for Microwave Transistors 
[IJ
The problem: 
The present electronics market offers a wide variety 
of semiconductor packages designed for a multitude of 
applications. Many are hermetically sealed components 
that satisfy low-frequency applications. However, the 
majority cannot be used with components designed for 
high-frequency, high-power leveis, particularly in the 
microwave range. These packages are not designed for a 
usable and predictable characteristic impedance at RF 
frequencies. In addition, many are not designed to 
withstand hostile environments and cannot interface 
with various circuit configurations (such as coaxial, 
stripline, and microstripline). 
The solution: 
One semiconductor package has been developed for 
high power semiconductor devices that operate in the 
GHz-frequency range at several watts. The package is 
mechanically strong and can be used with a wide variety 
of circuits. 
How it's done: 
The package (see figure) includes a stud, an insulating 
ring, andelectrically conductive washer, an insulating 
washer, a braze ring, and a cap. The stud is cylindrically 
shaped on one end and conically shaped on the other. 
The cylindrical end is undercut adjacent to the outer 
tip. The conical end terminates in a blade-shaped outer 
tip. This tip ends in a plateau for mounting a semi-
conductor component. The stud also include a flange 
in the middle which supports an insulating ring. The 
insulating ring ends in a plane that intersects the blade 
portion of the conically shaped end. 
An electrically conductive washer is mounted on the 
other surface of the insulating ring. The washer has a 
slotted aperture at its center which fits about the blade-
shaped end of the stud but is se parated from it. In
addition, the washer has a pair of oppositely-located 
semicylindrical apertures on its periphery that allow the 
package to be bolted in place. 
Located on the other surface of the electrically 
conductive washer is the insulating washer. The insulating 
washer also has a slotted aperture at its center. On the 
other side of the insulating washer is a braze ring. In 
essence, the braze ring is flat, washer shaped, and has a 
circular inner aperture that is considerably larger than 
the slotted aperture in the insulating washer. On the 
other side of the braze ring is the cap that rests on the 
opposite surface of the braze ring. 
Semiconductor	 Slotted 
Component	 Aperture 
Hermetically-Sealed Semiconductor Package for 
High-Frequency, High-Power Components
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ze 
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(continued overleaf) 
This document was prepared under the sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States 	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States 	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19730000427 2020-03-17T07:30:51+00:00Z
The stud is normally formed of silver or copper, as 
are the electrically conductive washer and the cap. The 
insulating ring is beryllium oxide (BeO), and the 
insulating washer is formed of alumina. Moreover, the. 
BeO insulating ring is metàlized with molybdenum 
manganese on both of its metal joining surfaces and 
then is plated with nickel. Similarly, the alumina 
insulator is also metalized on both metal contacting 
surfaces with molybdenum manganese but is plated 
with gold. 
The package is assembled as follows. A subassembly 
comprised of the stud, the BeO insulating ring, the 
conductive washer, and the insulating washer is formed 
by mounting these items as illustrated and brazing them 
together in a high-temperature furnace (8000 to 9000 C). 
The semiconductor component is then mounted on the 
flat conical tip of the stud, and connections are made 
from the semiconductor component to the conductive 
washer and to the metalized upper surface of the 
insulating washer. Thereafter, the braze ring and the cap 
are mounted. The entire structure is then placed in a die 
mounter, and the cap is brazed to the insulating washer 
to seal hermetically the entire assembly.
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Goddard Space Flight Center 
Code 207.1 
Greenbelt, Maryland 20771 
Reference: TSP73-10427 
Patent status: 
This invention has been patented by NASA (U.S. 
Patent No. 3,705,255). Inquiries concerning nonexclusive 
or exclusive license for its commercial development 
should be addressed to: 
Patent Counsel 
Goddard Space Flight Center 
Code 204 
Greenbelt, Maryland 20771 
Source: David S. Jacobson of

RCA Corp.
under contract to

Goddard Space Flight Center

(GSC-10791)
. 
[II 
B73-10427	 Category 01,08


Hermetic-coaxial package design for microwave transistors

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