MEMS power switch startup raises $44m

Business news | October 15, 2020

By Nick Flaherty

Materials & processes Power Management

“What we have done is reinvented the electronic switch,” said Russ Garcia, CEO of Menlo Micro. “We were born out of GE’s research labs where the engineers looked to reinvent the circuit breaker and they came up with this ‘Ideal Switch’. GE were looking to source the switches and chose MEMS. With the gap between the contacts we can switch kW of power in a device that scales like a transistor.”

The key is the material used in the MEMS switch and the fin-like design that avoids the problem of the switch sticking. It switches with picoamps of current at 70V.

“This works from DC to mm wave frequencies as well as scaling from mW to kW. The alloy is our secret sauce, we have exclusive rights. It’s fab friendly but not a material you would find in a fab and we use it to build a cantilever beam.”

“Today we have a 50um beam with a 1um gap and each beam carries 150mA and 200V. That beam is a unit cell that we characterise and we can network these in series or in parallel to scale the current and voltage.”

Menlo has a demo module with 200V 10A DC relays with multiple beams, and a 25W 20GHz switch with a smaller number of switches.

“Right now we guarantee three billion cycles, that’s the minimum. We have built the models and through the next year will continue to raise that up to 10, 20bn cycles. We have characterisation models that the contact structures and the metals we use show most go to 20bn cycles. This really solves t4he compromise between solid state and electro mechanical as we use far less energy to run on than a IGBT.”

“We have very low on resistance so we don’t burn power, and can switch so much current. For example a 200V dimmer module for lighting requires no heat sink. At the same time we are very linear to mmWave at 20Ghz and beyond and we have modelled above that for customers.”

“We entered the RF switching market first, that’s the low hanging fruit in test and measurement, aerospace and even in 5G infrastructure, as we can switch a lot of power. But we have also started engaging with multiple customers in relay and power distribution for the electrification of everything, in electric vehicles, aerospace, home energy distribution.

“The temperature range is a huge advantage,” he said. “With our 25W device at 20GHz the contact barely gets to 100C but we have characterised the device at over 200C and we have customers looking at temperatures in extreme heat and cold. That’s down to -45C at this point but applications go down lower for supercomputing.”

“In extreme temperatures you would have the drivers outside the package,” he said. These drivers are built in a 70V high voltage CMOS process. “Customers can add the driver into other devices – the only issue is making sure there’s a solid charge pump,” he said.

All of those attributes scale across the board.

“As we are developing the power products with the demo modules we will start seeing products in the next 12 to 24 months in areas such as high power wireless charging

“We build the devices in the Silex commercial fab as the expertise and equipment set mapped well there. We will scale this up over the next two to three years at that fab and we are planning the fab expansion for more capacity. In industrial IoT there a lot of opportunity the issue is to turn things on and off and that’s a big problem in the IoT. Switching lights or HVAC, that’s switching kW of power so that’s where we believe we have a real strong play long term.”

The round was led by 40 North Ventures alongside San Francisco-based Piva, Paladin Capital Group, Vertical Venture Partners, and Tony Fadell’s Future Shape. This round brings Menlo Micro to $78m in total funding from companies including Corning and Microsemi.

www.menlomicro.com

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