Microfabrica's 3-D MEMS

Microfabrica (previously MEMGen) is a MEMS start up that secured $15 million in venture financing last year.  We recently spoke with Adam Cohen, the EVP of Technology and CTO of the company.

MEMS Investor Journal: Microfabrica has positioned its EFAB process as its unique capability.  How does the EFAB process work and what are its unique advantages and benefits over other MEMS technologies?

Adam Cohen: EFAB technology is a microfabrication process based on multi-layer electroplating and planarization of metals. The process is designed to efficiently stack dozens of independently patterned metal layers on top of one another, allowing designers to create intricate 3-D complex geometries with micron-level precision.

EFAB technology is a flexible and versatile process that has the ability for creating complex 3-D microdevices composed of dozens (so far up to 50) layers (by comparison, the state-of-the-art for conventional MEMS processes is 5) that are otherwise impossible or impractical to make. This opens the door to enhancing performance and new functionality.

MIJ: What are the limitations of the EFAB process?

AC: There are three potential limitations of the EFAB process:

1) materials – most electroplated metals and alloys attach to insulate, however a sister process is under development to provide both an insulator and a metal for those few applications that need a structural insulator,

2) feature size - currently limited to 10-20 µm in the plane of the layers, and 2 µm perpendicular to this plane (but have not found a reason to go smaller than that)

and 3) sidewall quality - compared with LIGA it is not as good since its multiple layers vs. one.

MIJ: What kinds of applications are most optimally fabricated with the EFAB process?

AC: RF components/systems (especially microwave/mm-wave devices at GHz frequencies), safing/arming and fuzing devices for weaponry, multi-axis inertial sensors, surgical instruments and medical implants, high-force & long-stroke actuators, printheads and fluid ejectors.

Comments

[Flora Yee]

I would like to ask if there is an upper limit in terms of dimension for manufacturing using the EFAB process. What are the largest possible dimensions where EFAB can still be used?