For more than half a century, glass-to-metal seals served as the core element of the electronic packages manufactured by AMETEK ECP, which have proved essential to multinational corporations, governments' defense forces and countless other organizations in between. They functioned as the medium through which electronic signals and radio frequencies passed with no intrusion from outside elements.
Yet, advances in the ceramics industry have made it such that this material works as a highly viable alternative to glass in a variety of working environments. As such, AMETEK ECP began to incorporate ceramics into package design and found that feedthroughs, machined housings, fiber optic packages and other products benefited significantly from its use.
Major features of ceramic feedthroughs and high-temperature co-fired ceramic packages (HTCCs) include extremely high resistance to heat and corrosion and the capacity for frequencies with sizable wavelengths.
Structural basics
Layers of laminated ceramic "tape" - tiny pieces made from AMETEK ECP's proprietary aluminum oxide blend for ceramic powders - serve as the conduction method of HTCC packages. They range between 0.004 and 0.010 inches thick.
Ceramic tape is metalized prior to lamination so it can be brazed, wire bonded, or connected to a column depending on the application. The metalization process also creates the circuit patterns necessary for current conduction between tape layers. Finally, the package is sandwiched between a Kovar seal-frame and a lead or pin, also made of Kovar alloy.
Where ceramic bests glass
Make no mistake: Glass-to-metal sealed packages and connectors remain a prominent part of the AMETEK ECP product catalog. But certain attributes that the ceramics in our HTCCs possess dictate their superior compatibility for feed-through use:
- GTMS parts can crack under extreme heat, cold or pressure. HTCC components, by contrast, are invulnerable to this danger.
- HTCCs withstand temperature cycles ranging from -65 to 150 degrees Celsius. Overall, they feature greater heat resistance than GTMS connectors or low temperature co-fired ceramics (LTCCs).
- Ceramics weigh 3.6 grams per cc - a big drop from the 8.3 grams per cc of Kovar alloy.
- HTCCs aren’t damaged by conditions experienced in high-salt environments or applications involving prolonged moisture exposure.
- Intense mechanical shocks and vibrations can be withstood.
Major HTCC applications
Ceramic packages and feedthroughs help provide the closely connected electrical paths necessary for the tools used in the following sectors:
- Defense: Navigation, weapons guidance and communications systems for the armed forces, especially for infrared sighting and surveillance.
- Commercial aerospace: Motion sensors, SAT COM, programmable radio frequency amplifiers and more.
- Industrial: HTCCs and ceramic feedthroughs benefit integrated circuits, voltage regulators, motor controls and DC-to-AC power converters.
- Health care: Defibrillators, pacemakers and other cardiac equipment, in addition to imaging and monitoring devices.
- Optical: Laser devices, electro-optical modules, clock amplifiers, modulators and more.