Omega Micro Technologies, Inc. produces gold-plated silver substrates qualified and currently in use for military applications:
Historically, Low-Temp Cofired Ceramic (LTCC) has been the substrate of choice for many military and aerospace applications due to the
superior performance characteristics, enhanced design capabilities and ability to withstand the most rugged environments.
For reliability concerns, Military and other High-Rel product manufacturers traditionally design for all-gold material sets for both
internal and external conductors in LTCC substrates.
As the cost of gold increased over the years, new, less reliable mixed-metal sets were developed which use predominately silver internally, gold externally and a transition material to interface the two. Kirkendall effects between the materials have led to manufacturability problems and decreased packaging opportunities. These problems have forced many military and high-reliability designers to stay within an all-gold system.
Since the price of gold has more than doubled in the last five years, it has risen above $1400/oz and is quickly approaching $1500/oz [has peaked over $1540 - May 2011].
This significant cost increase has forced designers to sacrifice performance and capability in favor of less expensive substrate technologies.
Researchers at Omega Micro Technologies, Inc. saw this trend emerging years ago and defined a technological roadmap leading toward a proprietary electroless deposition of nickel/gold on silver substrate solution. This plating solution would provide for higher performance, fully-functional, high-reliability substrates at a fraction of the cost of the all-gold model.
After years of development, testing, qualification and implementation, OMT is manufacturing gold-plated silver substrates which are qualified and in use in military applications.
The Omega Micro Technologies’ proprietary plateable silver LTCC process utilizes a multilayer ceramic substrate constructed exclusively with silver conductors which are then electrolessly deposited with nickel, followed by a thin layer of gold. The resulting substrate may be wire bonded, soldered or brazed, and has the superior performance characteristics and capabilities desired as well as the potential for improved thermal conductivity to the all-gold model.
The cost of this new substrate utilizing nickel/gold deposition is comparable in price with traditional commercial substrates fabricated with all silver conductors, but with the reliability approaching that of substrates fabricated with all gold conductors, allowing the process to be used widely throughout the military marketplace with considerable cost savings to the U.S. military and armed forces.
Over the last two years, researchers for Omega Micro Technologies have been working with officials from various U.S. Department of Defense (DoD) Original Equipment Manufacturers (OEMs), as well as under a contract with the Indiana RF Alliance and Crane Naval Surface Warfare Center in southern Indiana in order to evaluate and characterize the performance and reliability of Omega Micro Technologies' electroless deposition process under standard military environmental operating conditions.
As a result of these efforts, OMT's gold-plated silver LTCC substrate technology has been qualified and accepted by a major DoD OEMs' U.S. Army Joint Tactical Radio System.
This intensive battery of testing - through aging, thermal and environmental cycling - has shown OMT's plated substrates have exceptional performance in: wire bond adhesion, ribbon bond adhesion, solder wetting, solder pad adhesion, leach resistance, migration resistance, ball shear strength, component shear strength, brazed lead pull strength, and seal-ring leak detection.
The cost savings potential of this process will allow LTCC substrates and modules with their superior performance and enhanced capabilities to be directly cost competitive with lower-performance, cheaper substrate technologies such as high-temperature cofired ceramic and potentially laminate and polymer material sets. This approach to the fabrication of LTCC substrates opens new areas of market potential for OMT's substrate technologies within both the military and the automotive and commercial marketplaces.
Please contact us for further information regarding gold-plated silver LTCC substrate design, manufacture and testing summaries.
