New product activity for relay and switch products has been in the doldrums since the markets dropped at the turn of the millennium. There have been some recent developments that deserve a look. First, a new micro-fabrication process enables the manufacture of true electromechanical relays equal in size to MEM’s relays without the drawbacks of using silicon-based materials. Then, push button switches with a brain and dynamic graphical displays enable complex user interface schemes with fewer switches.

New Process Produces Non-Silicon Based MEM’s Relays

HT MicroAnalytical, Inc. (HT Micro) of Albuquerque N.M. is developing micro-fabricated electro-mechanical relays. Initially, HT Micro was focused on low frequency applications, but plans subsequent relays that operate well into the RF. HT Micro’s relays are small surface mount devices with a footprint of 3X5 mm, which is approximately the same as the current RF-MEMS relays. However, they are electro-mechanical with a 1.5-volt actuation signal and present nearly as much contact force as a conventional small PCB mount relay. In a very small footprint, they have a measured carry current of more than 2 amps DC. Both mechanically latching and non-latching relays can be produced, both with normally open and/or normally closed contacts.

What’s Different?

HT Micro’s relays are fabricated using additive metal processing on a ceramic filled-via wafer. The resulting relays consist entirely of ceramic, copper and gold with high force metal springs and use established contact metallurgy. The packaging is a hermetic metal and ceramic structure with integral surface mount pads. Since the packaging is performed entirely at wafer scale and is an integral portion of the total fabrication process, the cost is quite low. The resulting relays are competitive in every way with existing electromechanical relays but offer significant size advantages and are expected to offer very significant cost advantages in high rate production. Because of the high contact forces, measured at more than 80 milliNewtons, contact stiction does not present the same issues as for silicon based MEMS relays that typically have only 100 microNewtons of contact force. Conventional contact metallurgies can be employed enabling hot switching in many applications.

What is the “Additive Metal” Fabrication Process?

This is a lithographic based micro-fabrication process that uses a plastic mold form to define the metal components used in the relay. The process can accommodate insulators, conductors, and ferromagnetic materials as required for a high performance electro-mechanical relay. Packaging is integral to the process resulting in a very low cost of manufacture.

How Broadly Applicable is this Process?

Products currently in development at HT Micro include not only relays, micro-connectors and other micro-electronics components, but also ion optics for a miniaturized mass spectrometer, implantable gold medical devices, impact switches, surety components including both safe and arm and arm/fire devices, and a number of other components in these or nearby market verticals.

What are the Next Steps Specific to Relays?

HT Micro intends to complete a second design iteration of its current prototype relays and then offer them for test to selected customers. The company also plans to fabricate relay arrays in a single BGA package with 32 and 64 relays per package. Because of very low NRE costs for layout modifications in such a package, the relay arrays will be offered with low cost custom internal layout and interconnect options based on relatively small production runs. Future plans also call for high power relays that operate up to 10-20 GHz allowing both transmit and receive side switching for communications applications as well as facilitating automatic test applications with higher power signals.

New SmartSwitch with RGB Backlighting

The SmartSwitch offered by NKK Switches of Scottsdale, Ariz. integrates an LCD display, microprocessor control, and a push button switch to provide designers with a multi-function user interface switch. The latest innovation is to provide backlighting via an RGB LED that is capable of producing any color in the rainbow and changing that color depending on status of a variable, such as a high or low level, or the ambient environment.

Through programing, a single SmartSwitch is capable of performing multiple functions and communicating this to the operator via the LCD display. The display can show characters, graphics, and animation. Up to three lines of seven alpahnumeric characters can be displayed. Graphics and animation can be programmed by turning pixels on or off in a 36 by 24 matrix. The output is a SPST switch capable of a 100mA load at 12V DC. Multiple switches and displays (see photo) can be combined to handle more complex control schemes.

The programable SmartSwitch offers an intelligent pushbutton that maximizes function while minimizing panel real estate. Suited for a wide variety of applications the SmartSwitch can be applied in industrial controls; radio, television, and cable broadcast equipment; simulation equipment; telecommunications gear; medical and laboratory instruments and equipment; military systems; and technology for financial institutions.

How Keep to Innovation Alive

Intorducing innovative new products is the most important activity for any manufacturer. It truly provides an opportunity to differentiate themselves from competitors and permits them a premium price for the period it takes for like products to be introduced. Many manufacturers work closely with individual customers to develop niche products for specific applications. The resulting new product may not have larger market appeal or the customer may be able to restrict the sale of the product to others. This method of product development may limit risk as well as reward. More development of innovative new products, like those described above is needed to keep the switch and relay business prospering.