Karen W. Markus

Smart MEMS: flip chip integration of MEMS and electronics

This paper will describe a new approach to the integration of electronics with MEMS, or Smart MEMS. Flip chip solder bumping of integrated circuits is routinely used for packaging purposes and has now been extended to the placement of electronics in close proximity to MEMS devices. The flip chip approach separates the fabrication of the MEMS and electronic devices, allowing both the ICs and MEMS to be fabricated of many different substrate materials, not just single crystal silicon. The close proximity of the electronics to the MEMS devices is very desirable to improve signal to noise performance, and provide higher levels of systems integration. This new approach provides batch fabrication capability as opposed to the serial hybrid approach, without having to fabricate the electronics and MEMS on the same chip. Results on the attachment of surface micromachined structures to glass and silicon substrates will be reported.

MEMS infrastructure: the multiuser MEMS processes (MUMPs)

In order to help provide access to advanced MEMS technologies, and lower the barriers for both industry and academia, MCNC, and ARPA have developed a program which works to provide users with access to both MEMS processes and advanced integration techniques. The two distinct aspects of this program, the MUMPs and Smart MEMS, will be described in this paper. The multi-user MEMS processes (MUMPs) is an ARPA-supported program created to provide inexpensive access to MEMS technology in a multi-user environment. MUMPs is a proof-of-concept and educational tool to aid the developemnt of MEMS in the domestic community. MUMPs technologies currently include a 3-layer polysilicon surface micromachining process and LIGA processes that provide reasonable design flexibility within set guidelines. Smart MEMS is the development of advanced electronics integration techniques for MEMS through the application of flip chip technology.

A novel two axis actuator for high speed large angular rotation

Reports the development of a novel two axis rotary actuator capable of high frequency out-of-plane rotation in two fully independent axes with large angular excursions. Initial results indicate that using the novel suspension and actuation mechanism presented permits large rotations exceeding /spl plusmn/13.5 degrees at rotational speeds exceeding 15 kHz, using excitation voltages below 100 V. The device is fabricated using a combination of surface and bulk micromachining. In this work the actuators are used to rotate single crystal silicon plates of sizes up to 1 mm/sup 2/. The size of such a device is less than 4 mm/sup 2/ making it suitable for a variety of new applications, such as micropositioning systems, inertial systems, microoptical elements, and compact imaging systems.

MEMS: small machines for the microelectronics age

In the past few years, the micro-electromechanical systems (MEMS) industry has exceeded the

Developing infrastructure to mass-produce MEMS

1-billion-a-year mark. Some economic forecasters estimate that the industry will surpass

MEMS: the systems function revolution

14 billion by the year 2000. The reason for this tremendous growth is the enabling nature of MEMS, which give engineers and researchers the tools to build things that have been impossible or prohibitively expensive with other techniques. MEMS are micron- to millimeter-scale devices that can be fabricated as discrete devices or in large arrays. MEMS borrow much of their technology from integrated circuit (IC) manufacturing, providing three-fold benefits: miniaturization, multiplicity and microelectronics. First, miniaturization of the devices is inherent in the processing techniques. Modern microelectronics fabrication techniques are designed to build submicron-scale devices. By using the same techniques, engineers can easily leverage this technology to produce MEMS that are orders of magnitude smaller than their macroworld counterparts. Second, the use of photolithography techniques makes producing thousands or even millions of copies of a single device easy. Thus, single devices can be arrayed into systems to produce an effect impossible with discrete devices. Finally, because MEMS technology is so similar to IC fabrication technology, MEMS are integrable with microelectronics.

Characterization study of flip chip integration for MEMS

Though microelectromechanical systems are often made from silicon, the existing semiconductor technology base faces numerous challenges to meet the special requirements of fabricating MEMS devices. To realize economies of scale, seven aspects of MEMS manufacturing infrastructure must be improved: computer aided design and simulation; lithography; etching; parametric testing; functional testing; packaging; and capital equipment.

Integration of MUMPS and electronics for system prototyping

Information systems are no longer confined to desktops but are rapidly becoming part of cars, personal digital assistants, and palmtop systems. In this context, systems must be able not only to compute but also to sense their physical environment and respond to it. These requirements move beyond even complex microelectronics, calling for a functionality that combines electrical and mechanical components. This new functionality is realized in microelectro-mechanical systems (MEMS). MEMS devices are fast becoming part of everything from automobiles and fighter aircraft to printers and telecommunications switching equipment. According to the authors, despite some obvious advantages, MEMS are not well understood by the systems design and applications community, ironically, the ones to whom MEMS offer the greatest opportunities for enhancing system functionality. One area of confusion is how MEMS are produced and how that process differs from microelectronics manufacturing. The authors explain similarities and differences and identify some trends and motivations leading to a new systems functionality.

Microelectromechanical devices including rotating plates and related methods

This paper will describe the characterization study conducted to determine the suitability of Flip Chip integration of electronics with MEMS. Successful demonstration of the operation of various MEMS devices in conjunction with Flip Chip is reported. Flip chip solder bumping of integrated circuits is routinely used for packaging purposes and has now been extended to the placement of electronics in close proximity to MEMS devices. The flip chip approach separates the fabrication of the MEMS and electronic devices, allowing both the ICs and MEMS to be fabricated of many different substrate materials, not just single crystal silicon. The close proximity of the electronics to the MEMS devices is very desirable to improve signal to noise performance, and provide higher levels of systems integration. This new approach provides batch fabrication capability as opposed to the serial hybrid approach, without having to fabricate the electronics and MEMS on the same chip. Results on the characterization study of attachment of surface and bulk micromachined structures to glass and silicon substrates is reported.

Reflective mems actuator with a laser

In order to create true Smart MEMS systems, the integration of electronics with the MEMS devices is essential. There are currently three methods of integration available: monolithic integration, flip chip attachment and hybrid assembly. The use of flip chip attachment for Smart MEMS has previously been described, and is now available as part of the ARPA- supported MEMS infrastructure programs MUMPs and TechNet. This paper will describe the electromechanical control system chip and the method of using it in conjunction with MUMPs to develop Smart MEMS prototypes.