Category Archives: Packaging and Testing

The 10th Annual MEMS Technology Symposium sponsored by MEPTEC (MicroElectronics Packaging and Test Engineering Council) was held May 23 at the San Jose Holiday Inn. This year’s theme was “Sensors: A Foundation for Accelerated MEMS Market Growth to $1 Trillion.” Registered attendance was ~230.

The conference opened with a keynote address by Prof. Kristofer Pister, UC Berkeley speaking on sensory swarms. Inexpensive, wireless sensor networks have moved out of the lab and are being implemented in myriad applications. A refinery in Richmond, CA has methane gas sensors at every valve to monitor emissions. Parking spaces in San Francisco and Hollywood are tagged with car sensors to provide dynamic signage directing drivers to open spaces; this system also communicates with a smart phone app (“Parker”) to take you to specific open spaces. Rail cars have temperature and vibration sensors on every truck for predictive and preventive maintenance. Wireless sensors in the field are projected to top 1.1 billion units by 2015, up from 168 million units in 2010.

Janusz Bryzek, VP Fairchild Semiconductor, revisited his theme of accelerating the MEMS market to $1 Trillion and 1 trillion units. A $1 wireless sensor unit will require a 20¢ internet access module. The HP notion of a central nervous system for the earth will call for an average of ~1,000 sensors for every person. Smart phones have spurred the initial growth burst for MEMS, but the internet of things represents the “largest growth opportunity in the history of business.” Factors slowing MEMS market development include relatively slow MEMS process R&D cycles, and a lack of industry standards for manufacturing, packaging and testing. The fusion of computing, communication and sensing has been characterized as the third industrial revolution by Vijay Ullal of Maxim. While manufacturing jobs continue to be outsourced, the profitability and job creation potential at the innovation, design and marketing end remains a lucrative economic driver for the US.

Robert Haak of MANCEF described the implementation of the $1T MEMS roadmap. The key technologies needed for success include RF, chemical measurements, energy sourcing, inertial measurements, pressure measurements, acoustic sensors and displays. The industry roadmap infrastructure needs to evolve to a 3rd generation that focuses on products that are conceived at the interface of more than one technology. Specific roadmaps proposed are sensors, data transfer and data processing equipment. These are proposed to have a 15 year outlook with a 5 year review cycle.

Richard Friedrich of HP Labs spoke of the aforementioned central nervous system for the earth, CeNSE: awareness through a trillion MEMS sensors. The subtitle of his talk proclaimed this as the decade of sensing and sense-making. True more for technology than for politics. The infrastructure behind this enterprise will require about 1,000x more bandwidth than today’s internet has available. His vision projects ~150 sensors for every person on the planet, fewer than the second speaker but with a focus specifically on CeNSE applications. A MEMS nanofinger substrate for surface enhanced Raman scattering  (SERS) provides a signal enhancement factor of 1011, enabling a detection sensitivity of 0.02 parts per trillion. The use of people as sensors is manifest in real time analysis of Tweets for regional tuning of marketing campaigns. The HP Social Computing Lab claims 97% accuracy in predicting movie revenues based on the response to pre-release advertising. Work is underway to simulate the human brain visual cortex using a system with 64,512 cores that has demonstrated the ability to learn without being taught. The root objective of a CeNSE network is to convert the flood of data into insight that leads to action. Skynet?

Greg Galvin, CEO of Kionix, presented another perspective of sensing the future on the road to a $1T market. They focus solely on inertial sensors, which had a 2004-2011 unit CAGR of ~100%. Unit prices of accelerometers, compasses and pressure sensors are already well below $1, with gyroscopes to follow by 2015. MEMS components have been averaging 2% of the end cost of products that use them. His conclusion was that a $1T market for MEMS over the next 10 years is unlikely, even though a 1T unit market is probably, and a $1T market for MEMS-enabled devices is a given.

Jérémie Bouchaud of IHS iSuppli couched his perspective as a “MEMS revolution: from billions to trillions?” The 5 year MEMS CAGR is presently running at 9.7% for revenue overall and 20.7% for shipments. Smart phones by themselves have a 17.8% revenue CAGR, and are a significant market driver. MEMS microphones are another beneficiary of smart phones, which now include multiple microphones for both speaking and for background noise suppression. Despite the myriad growth opportunities, he believes the prospect of a $1T MEMS market will require price points ≤5¢ per unit, and an expansion of the market definition to include sensors for temperature, light, humidity, UV and others.

The afternoon keynote was delivered by Steve Nasiri, founder of InvenSense, a big player in the motion interface MEMS market. Just 3 applications, mobile handsets, media tablets and gaming represent a $2.4B market by 2015. The gyro market was slow to get started until Apple put one in the iPhone in 2010. Within a year, over 70 other models were on the market with gyros, even though some didn’t seem to know what to do with them. The wearable sensor market for remote patient monitoring, home monitoring, sports & fitness will push to $150M by 2015. Does your mother live too far away to tell you not to slouch? A shirt with an embedded posture sensor can handle that for her. InvenSense has just announced an open platform infrastructure to facilitate rapid MEMS applications development.

Jean-Christophe Eloy of Yole Développement provided a status of the MEMS industry with a focus on new drivers and the path to new opportunities. The overall MEMS market is ~$10B now, growing to ~$21B by 2017. While the MEMS markets continue to grow, they are still only ~10% of the value of the end markets they enable. Accelerometer / gyroscope systems with 6 degrees of freedom (DOF) have largely been displaced by newer systems with 9 or 10 DOF. All of the growth notwithstanding, he remains skeptical of a $1T MEMS device market.

Stephen Breit of Coventor took us to the software design side of the business with his comments on realizing the full potential of MEMS design automation. If invention is the first wave, and manufacturing differentiation is the second wave, then the third wave is going to be innovation in design and integration. This is the catalyst that will be needed and has the potential to drive the hyper growth if the industry is to hit the $1T mark. Simulation of the integrated MEMS system will make it possible to compress the development cycle from the 2009 benchmark of 4-5 years. This vision includes process design kits and MEMS design kits (modules) similar to the design efficiencies achieved in ASICs. Coventor has a partnership with IMEC that was facilitated by IMEC’s integrated SiGe CMOS + MEMS integration scheme.

Russell Shumway of Amkor took us to the end of the production line with a discussion of high volume assembly and test solutions to support a rapidly growing MEMS market. He anticipates that there will be a greater tendency toward package standardization over the next 10-20 years, but the variety of packaging options is so large that the diversity will still be formidable.

Tristan Joo, Co-Chair of Mobile SIG of the Wireless Communications Alliance reviewed a few case studies of fusing sensors into mobile operating systems. Current smart phones already contain 12-18 sensors, including inertial, optical, touch, audio, magnetic, geo-positional and environmental. The future has a context-aware sensory data cloud in store for us. Smart phone apps that take full advantage of these sensors amount to less than a 0.5% share of apps downloads across all iPhone, Android and Windows OS platforms. I myself can use my smart phone as a bubble level, an audio dB sound meter, a thermometer, a compass, a ruler, a document scanner and a mechanical energy harvester to recharge my battery. But I’m a geek.

The remaining scheduled time comprised six brief presentations by companies showcasing new applications under the banner of “MEMS for the Rest of Us.”

Hillcrest Labs provides motion control systems for consumer electronics and other markets. Their flagship platform is the Freespace® MotionEngine™ that includes a gesture recognition engine and a variety of mobile, gaming and TV applications.

Movea develops data fusion software for processing sensor data into usable information. It is a spin-off of CEA-Leti in France. Fundamental elements of human motion have been compiled into a periodic table, cleverly presented as the Chemistry of Motion.

Sensor Platforms provides data fusion software in their FreeMotion™ library with the objective of being hardware agnostic. He favors mobile devices that respond to human action and context, not in the sense of obeying gestures and commands, but more in the sense of recognizing what’s going on and acting accordingly. For example, when your smart phone calendar says you’re in a meeting, a really smart phone will silence most calls and allow vibration only for a select short list of callers. The end result is to use the available data and context to anticipate intent.

Syride makes a rugged sports-oriented GPS device for tracking speed, elevation and location for hobbies such as surfing, sailing, skiing, skydiving and hang gliding. I use “Map My Walk,” which I will henceforth think of as the couch potato analog of Syride.

VectorNav Technologies is a hardware and software company that takes consumer level motion systems and upgrades them to industrial strength using established aerospace technology. Applications include human exoskeletons for the handicapped, and human motion capture for movies and medical applications. I’m pretty sure I misunderstood when I heard something about a home Cruise missile.

Xsens specializes in sensor fusion software for smart phones, tablets and sports applications. On-body MEMS sensors enable a new paradigm for body motion capture, embodied in a 17 sensor system integrated in a Lycra body suit. The system has already been used in developing video games.

May 24, 2012 — Bosch Sensortec, the consumer electronics sensor arm of Bosch, has integrated two triaxial micro electro mechanical systems (MEMS) sensors in 1 package, claiming the smallest inertial measurement unit (IMU) to date. An optional geomagnetic sensor creates a 3DoF module. Solid State Technology spoke with Leopold Beer, director of global marketing at Bosch Sensortec, about MEMS integration and the sensor fusion software element of sensing.

The BMI055 combines an acceleration sensor and a gyroscope for advanced consumer electronics applications with six degrees of freedom (6DoF), such as gaming applications in smartphones, tablets, consoles, etc. It is packaged in a 3.0 x 4.5 x 0.95mm LGA.

The BMI055 is enabled by continuing miniaturization of MEMS, Beer noted, adding that Bosch fabs all of its MEMS chips in house with high-volume and high-reliability production.

Power is also important for the 2 MEMS package. The accelerometer and higher-power-consuming gyroscope can operate independently, when sensor fusion is not required.

“The MEMS are full-performance sensors in their own right, because customers are used to a certain set of functionality from accelerometers and gyroscopes,” Beer said, “that cannot be compromised for small form factor.”

The accelerometer features flexible interrupt functionality and integrated FIFO buffer. The gyroscope features an integrated interrupt engine, integrated FIFO buffer, and 4 offset compensation modes. For greater design flexibility, the measurement range of the sensors is programmable:  ±125°/s to ±2000°/s for the gyroscope, and ±2g to ±16g for the accelerometer. The latter also shows a low zero-g offset of typically 70 milli-g. The gyroscope has a 16 bit resolution; the accelerometer’s is 12 bit. The gyroscope boasts stable operation with good TCO and offset compensation. The package offers good signal to noise ratio. I2C and SPI digital interfaces offer versatile communication options.

The BMI055 IMU is released concurrently with Bosch’s custom sensor fusion software BSX2.0 FusionLib that optimizes sensing by combining input from the gyroscope and accelerometer. MEMS manufacturers know the functionality and performance of each type of MEMS sensor best, Beer said. Therefore, MEMS makers are the ideal designers of MEMS sensor fusion software. “The algorithms in MEMS software do more than just drive the chip, they integrate abilities from each MEMS to improve calibration, interference filtering, and more.” Sensor fusion, for example, combines the good angular resolution but high drift of gyroscope MEMS with the slower eCompass, improving accuracy. BSX2.0 FusionLib works with all stand-alone or integrated Bosch Sensortec MEMS devices.

Bosch Sensortec makes MEMS devices for consumer applications, as a division of Bosch. Learn more at www.bosch-sensortec.com.

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May 10, 2012 — MEPTEC will host its 10th Annual MEMS Technology Symposium, May 23, in San Jose, CA. Keynotes cover “sensory swarms” and motion interfaces, and sessions will cover the micro electro mechanical systems (MEMS) roadmap; design, manufacturing, and test of MEMS; MEMS architectures and uses, and more.

Professor Krisofer Pister, Electrical Engineering and Computer Science at University of California, Berkeley, will deliver the morning keynote, titled, “Sensory Swarms.” In the afternoon, Steve Nasiri, founder, president, CEO and chairman, InvenSense, will present “Motion Interface the Next Large Market Opportunity.”

Sessions and session chairs:

  • The MEMS Revolution: from Billions to Trillions?
        Jérémie Bouchaud, Director and Senior Principal Analyst MEMS and Sensors, IHS iSuppli
  • Realizing the Full Potential of MEMS Design Automation Software 
        Stephen Breit, Ph.D., Vice President Engineering, Coventor, Inc.
  • Roadmap to a $Trillion MEMS Market 
        Janusz Bryzek, Ph.D., VP MEMS Development, Fairchild Semiconductor
  • Integration of the Accelerometer — the First Step of the MEMS Revolution
        JC Eloy, President and CEO, Yole Développement
  • CeNSE: Awareness through A Trillion MEMS Sensors 
        Rich Friedrich, Director of the CeNSE program, Hewlett-Packard Labs
  • On the Road to $1T?
        Gregory J. Galvin, Ph.D., President/CEO, Kionix, Inc.
  • Implementing the Trillion Dollar MEMS Roadmap
        Robert Haak, Managing Director, Insight interAsia Pte Ltd., Vice President – Asia/Pacific, Executive Board of Directors, MANCEF
  • Fusing Sensors into Mobile Operating Systems & Innovative Use Cases
        Tristan Joo, Board Director & Co-Chair of Mobile SIG, Wireless Communications Alliance
  • High Volume Assembly & Test Solutions to Meet the Rapidly Growing MEMS Market
        Russell Shumway – Sr. Manager, MEMS & Sensor Packaging, Amkor Technology

Register for the symposium at http://meptec.org/meptectenthannuc.html.

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May 8, 2012 – PRWEB — Si-Ware Systems (SWS), provider of integrated circuit (IC)– and micro electro mechanical system (MEMS)-based solutions for industrial and consumer applications, launched its Inertial Sensor Development Platform, the SWS61111 (formerly SWP210), a tool that can be used to evaluate an inertial sensor, such as a gyroscope or accelerometer, to understand sensor behavior and performance with complete interface electronics.

The SWS61111 utilizes SWS’s high performance inertial sensor interface ASIC, the SWS1110 (formerly SWI210). The SWS1110 is a configurable ASIC that has been successfully interfaced to multiple accelerometers and gyroscopes achieving best-in-class performance that exceeds that of competing MEMS sensor modules in the market today. With its ultra-low noise front-end, highly configurable open- and closed-loop (force-feedback) operation and high voltage capabilities, the SWS1110 is a perfect MEMS interface for high-end inertial sensing devices.

SWS’s SWS61111 is designed to allow for the quick and easy interfacing of almost all capacitive MEMS devices to comprehensive and high performance electronics. Rapid and detailed evaluation of issues such as parasitic modes of oscillation, electrical and mechanical coupling, high-volt effects and temperature behaviours provide crucial insight to MEMS and ASIC designers. This enables rapid time-to-market and concurrent optimization of MEMS and electronics. The SWS6111 also serves as a tool to evaluate SWS’s SWS1110 high performance ASIC, which is offered in die format with optional customization, for product targeting the high-end segment.

“For a number of years now we have been developing and utilizing development platforms internally that allow us to quickly and accurately understand and model the behavior of our partners’ MEMS devices,” said Ayman Elsayed, ASIC solutions division manager at Si-Ware Systems. “With a thorough understanding of the MEMS device and its behavior with interface electronics, potential pitfalls can be avoided and an interface ASIC can be developed much more efficiently.”

The SWS61111 consists of a programming board, an ASIC daughter board with a sensor placeholder, a USB interface, and associated PC software. SWS provides options for mounting the sensor to the daughter board, including creating custom daughter boards to match a particular sensor. Through an easy to use software interface, the MEMS sensor can be interrogated and the ASIC parameters configured to best match the sensor. If desired, the ASIC parameters can then be burned into the memory of the ASIC and the sensor-ASIC daughter board can be removed and utilized for system level measurements.

In addition to its experience with MEMS inertial sensors, SWS has worked with piezoelectric sensors, MEMS resonators, and MEMS optics. The company has developed an extensive IP library of electronics for MEMS and piezoelectric devices that can be utilized in the development of interface ASICs. The SWS61111 is the first development platform that SWS is making available to developers, but the company has many other internal development tools for the evaluation of MEMS or piezoelectric devices.

Si-Ware Systems is an independent fabless semiconductor company providing product design and development solutions, custom ASIC development and supply as well as standard products. For more information, please visit http://www.si-ware.com.

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May 2, 2012 – PRNewswire — Audio test tool supplier Audio Precision (AP) released a pulse density modulation (PDM) audio interface option on its APx500 for direct I/O, modulation, and decimation for designers of micro electro mechanical system (MEMS) microphones and other PDM devices.

Learn more about the APx PDM interface here.

PDM is a one-bit, high rate data stream that conveys a signal by modulating the density of the pulses. AP’s PDM option supports 4th and 5th order modulation; interpolation ratios of 32, 64, 128, and 256; and the ability to analyze an undecimated PDM bitstream.

A 50x interpolation ratio will be available in Summer 2012.

The PDM option includes a built-in power supply for devices under test (DUT), and can directly measure power supply rejection (PSR) in PDM devices. Users must have APx500 v3.0 software, which may be downloaded free of charge.

AP’s audio test instrument APx500 also includes a new PESQ software option for fully automated testing of speech quality with any audio interface, generating MOS (Mean Opinion Score) results. The APx PESQ software option allows the results of many tests to averaged, and may be used with any audio interface, including analog, DSIO, Bluetooth and PDM. In addition to support for PDM and PESQ, APx500 v3.0 enhances the DSIO (Digital Serial In/Out) with support for up to 16 channels of TDM at 96 kHz, variable TDM word length and accommodations for TDM variations used in a wide range of DSP products.

Audio Precision makes audio test instruments and applications. For more information, visit http://ap.com/.

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Contributing editor Steve Groothuis reviews a book titled “Energy Harvesting for Autonomous Systems (Smart Materials, Structures, and Systems).” The book is by Stephen Beeby (Author, Editor), and Neil White (Editor).

Enhancing energy and power capacity in industrial, mobile, and consumer devices may be the inflection point in guiding energy harvesting from a specialty market into the mainstream consumer market.  Energy harvesting is can be viewed as a practical approach to powering autonomous systems.

This book highlights the progression from the basic principles behind energy harvesting to the comprehensive systems that control the sensing, actuation, and transmission of those devices.  The basic principles include solid state physics, mechanics, chemistry, electronics, and general engineering.

The authors develop detailed discussions of the options for “harvesting energy from localized, renewable sources (e.g., photovoltaic, kinetic, thermoelectric) and their supply of power to autonomous wireless devices and systems”. The reader is exposed to various types of autonomous system and wireless networks which may not be apparent from and energy harvesting perspective.

The book focuses on the most promising harvesting techniques, including solar, kinetic, and thermal energy.  The reader will also learn the implications of the energy harvesting techniques on the design of the power management electronics in a system. This book is a comprehensive guide and discusses each energy-harvesting devices/systems with a high resolution.  The authors are aware enough to mention the pros and cons of their approaches and the similarities and differences between competing energy harvesting systems.

In order for these autonomous systems to be successful, one needs to understand the need for a high—efficiency energy storage (e.g., microbatteries and supercapacitors), a robust power management, lower power dissipation to the environment for maximizing the system’s viable in today’s energy market.

In the final chapter, a contributing author (Neil Grabham) pulls together a case study with all of the key careabouts in constructing a complete system for harvesting energy and using it in productive systems.  From designing hardware and software to developing a more intelligent system that is energy-aware, the reader can leverage all of the details from the previous chapters to draft a simple to more complex autonomous system for harnessing energy harvesting devices.  With recommendations on choice of microprocessors, reasoning of energy storage modules, and energy management schemes, the imminent success of designing, developing, and manufacturing such a autonomous system is ensured.

The book provides a distinguished list of contributing authors, a healthy number of references at the end of each chapter, and a sizeable number of schematics and diagrams to help the reader visually.  The book separates itself from other similar works by reiterating the unified theme of structuring communication hardware, energy management, and intelligent sensing throughout the entire book.  Pulling this theme off with multiple contributing authors is a sign of great editors wanting the reader to focus on the essentials of Energy Harvesting for Autonomous Systems.

About the reviewer: Steve Groothuis started his career at Texas Instruments in Dallas, TX in 1983 as a Package Technologist.  He worked on both sustaining and new package development projects.  His major focuses at that time were: package reliability, package simulation, and design for manufacturability.  Prior to leaving TI, he was TI’s Advanced Semiconductor Packaging Lab Manager with a diverse engineering staff. In 1997, he was a Multiphysics Industry Specialist for ANSYS, Inc., defining Computer-Aided Engineering simulation software market plans, strategic accounts management, electronics packaging, MEMS initiatives, and product development for the electronics industry.

From 2000-2008, his responsibilities started as Senior Package Engineer and evolved to Technology CAD  & Analysis Manager in the Process R&D Department at Micron Technology.  His responsibilities included working with device and process simulations for new cell designs, supporting most aspects of semiconductor package simulations, and assessing new technology.

From 2008-2011, he was a Principal Consulting Engineer with SimuTech Group, Inc. He was actively involved in developing & winning new business opportunities in CAE consulting projects. His efforts are focused on markets such as semiconductors, MEMS, semiconductor packaging license litigation, and Alternate Energy. Mr. Groothuis returned to Micron Technology as a Sr. MTS and Simulation Group Manager focused on 3DI package development, Hybrid Memory Cube, Emerging Memory technologies, and wafer-level manufacturability & reliability.

April 26, 2012 — The College of Nanoscale Science and Engineering’s (CNSE) Smart System Technology and Commercialization Center of Excellence (STC), Canandaigua, NY, was designated as a Trusted Foundry by the US Department of Defense’s (DOD) Defense Microelectronics Agency.

The Trusted Foundry program is a DOD initiative to accredit trusted, secure sources for IC development and manufacturing for various defense and intelligence applications. With the accreditation, CNSE’s STC can now serve the DOD, intelligence agencies, allied foreign governments, and government contractors. STC houses over 30,000 square feet of certified cleanroom facilities to enable fabrication, packaging and testing.

The designation was achievable through STC’s ability to meet the International Traffic in Arms Regulations (ITAR), and the expansion of its secret security clearance through the Defense Security Service (DSS). In addition, DMEA requires all Trusted sources to maintain ISO registration, with CNSE’s STC having achieved ISO 9001:2008 certification at the end of 2011.

CNSE’s STC is New York’s only Trusted Foundry for the processing, packaging and assembly of micro electro mechanical systems (MEMS) and optoelectronic devices.

In recognizing the designation, New York Governor Andrew M. Cuomo noted work to make the state “the epicenter of the global nanotechnology industry…through smart and targeted investments.” The classification as a Category 1A Trusted Foundry will help CNSE’s STC drive “new technology companies and high-tech jobs to the nanotechnology cluster in Western New York,” said CNSE SVP and CEO Dr. Alain E. Kaloyeros.

Next-generation MEMS are used in field-deployable, multi-functioning nanosensors and actuators, integrated system-on-a-chip (SOC) and system-in-a-package (SIP) technologies, and protective coatings and materials for the safety and security of military personnel and equipment, among other nanotechnology-based military applications. Also read: CNSE wins 6M in sensor projects for military power gen

The Trusted Foundry program seeks to maintain technological superiority for the U.S. military and ensure national security. Due to the rapid pace of technological development and the commercial microelectronics technology business climate that has shifted a significant amount of computer chip manufacturing offshore, that security is at risk. The Office of Secretary of Defense issued the Defense Trusted Integrated Circuits Strategy that established "Trust" as a minimum need for the Department of Defense in 2003 to address this risk.

Learn more about CNSE’s STC at www.cnse.albany.edu.

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April 23, 2012 – GLOBE NEWSWIRE — Hexagon Metrology released the Optiv Classic 321GL tp benchtop vision-measuring metrology system for the North American market. It suits electronics and precision parts inspection, including micro-holes, fiber optics, filters, and more.

It features 6.5x motorized CNC zoom optics for 0.002mm accuracy. Touch probes can be added for multi-sensor measurement. The Classic 321GL tp is the smallest model in the Optiv product line. It offers calibrated lighting, a high-resolution color CCD camera, a laser locator and an 8-segment LED dual angle ring light. The LED ring and software controls for red/green/blue sensitivity enable better edge detection, including for colored parts where edges can be difficult to capture.

The Classic 321GL tp includes PC-DMIS Vision image processing software and full online 3D CAD capabilities for live programming of the machine to compare measured values to nominals. The software’s MultiCapture feature finds all 2D characteristics in the field of view, measures them simultaneously, and moves the camera for the next cluster, optimizing the path of stage movement. Inspection speeds can increase by 50% or more.

The tool is made on a granite base with mechanical bearings.

Hexagon Metrology is part of the Hexagon AB Group. Hexagon is a leading global provider of design, measurement and visualization technologies. Learn more at www.hexagon.com.

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April 19, 2012 — Pure-play MEMS foundry Silex Microsystems brought its Met-Via full-wafer-thickness through silicon via (TSV) technology into Chip Architectures by Joint Associated Labs for European Diagnostics (CAJAL4EU), where it is being used to create cost-effective molded chip-level packaging with through metal vias (TMV).

Figure 1. Cross section of final product, showing Biosensor from NXP (Netherlands), TSV interposers from Silex, and epoxy mold to be performed by Frauenhofer (Germany) and gold (Au) bumping by Pactec (Germany). Frontside RDL to be processed by Bosch (Germany), and backside RDL to be processed by Frauenhofer (Germany).

The program is developing nanoelectronics-based biosensor technology platforms for in-vitro diagnostic test manufacturers to rapidly build various new multi-parameter test applications cost-effectively. CAJAL4EU will develop a generalized platform for low cost biofluidic sensing. Biosensing allows for rapid detection of unique biological markers (proteins, antibodies, and other biomarkers for infectious diseases) from microliter fluid samples in an extremely controlled environment. The biosensors will consist of a nanoelectronics-based transducer with an interface chemistry, which makes the connection to the clinical sample to be analyzed. With on-chip detection electronics, small electrical changes can be detected within milliseconds, enabling massively parallel real-time monitoring of bio-molecule binding events. Besides the transducers, interface chemistry and spotting technologies, microfluidics, software and hardware developments (and their integration) will play a crucial role to realize fully integrated biosensor systems and lab-on-chip devices. Therefore, the main deliverables of this project are the different developed technologies: sensor technology including bio-chemical functionalization, microfluidics and related hardware and software drivers.

Figure 2. Actual TSV interposer die from Silex.

Silex

April 13, 2012 — Georgia Institute of Technology researchers have used magnetic repulsion force as a fixtureless, noncontact tool for measuring the adhesion strength between thin films in microelectronic devices, photovoltaic cells, and micro electro mechanical systems (MEMS).

The magnetically actuated peel test (MAPT) could help electronics engineers understand and predict delamination/debonding, and improve resistance to thermal and mechanical stresses.

Figure 1. A specimen fabricated for the magnetically actuated peel test (MAPT). The silver cylinder in the center is the permanent magnet. SOURCE: Thin Solid Films.

The right materials will enable smaller, higher-performance, reliable electronic devices, said Suresh Sitaraman, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “This technique would help manufacturers know that their products will meet reliability requirements, and provide designers with the information they need to choose the right materials to meet future design specifications over the lifetimes of devices.”

Thermal stresses occur when different layers within an electronic device have mismatched coefficients of thermal expansion (CTE), and will cause layers to separate. Researchers want to know if these layers will separate as the device is used over time, eventually causing failure, said Sitaraman.

Figure 2. Georgia Tech School of Mechanical Engineering professor Suresh Sitaraman (left) and doctoral student Gregory Ostrowicki (right) examine a specimen (seen in Figure 1) fabricated for the magnetically actuated peel test (MAPT). SOURCE: Thin Solid Films.

Sitaraman and doctoral student Gregory Ostrowicki have used their technique to measure the adhesion strength between layers of copper conductor and silicon dioxide (SiO2) insulator. They also plan to use it to study fatigue cycling failure, which occurs over time as the interface between layers is repeatedly placed under stress. The technique may also be used to study adhesion between layers in photovoltaic systems and in MEMS devices.

The Georgia Tech researchers used standard microelectronic fabrication techniques to grow layers of thin films that they want to evaluate on a silicon wafer. At the center of each sample, they bonded a tiny permanent magnet made of nickel-plated neodymium (NdFeB), connected to three ribbons of thin-film copper grown atop silicon dioxide on a silicon wafer.

The sample was then placed into a test station comprising an electromagnet below the sample and an optical profiler above. Voltage supplied to the electromagnet was increased over time, creating a repulsive force between the like magnetic poles. Pulled upward by the repulsive force on the permanent magnet, the copper ribbons stretched until they finally delaminated.

With data from the optical profiler and knowledge of the magnetic field strength, the researchers can provide an accurate measure of the force required to delaminate the sample. The magnetic actuation has the advantage of providing easily controlled force consistently perpendicular to the silicon wafer.

Many samples can be made at the same time on the same wafer, generating a quantity of adhesion data in a timely fashion.

To study fatigue failure — a common failure mode wherein delamination occurs over time with repeated heating and cooling cycles, Sitaraman and Ostrowicki plan to cycle the electromagnet’s voltage on and off. “A lot of times, layers do not delaminate in one shot,” Sitaraman said. “We can test the interface over hundreds or thousands of cycles to see how long it will take to delaminate and for that delamination damage to grow.”

The test station fits into an environmental chamber, allowing the researchers to evaluate harsh-environment electronics under the effects of high temperature and/or high humidity. “We can see how the adhesion strength changes or the interfacial fracture toughness varies with temperature and humidity for a wide range of materials,” Sitaraman explained.

Sitaraman and Ostrowicki have studied thin film layers about one micron in thickness, but say their technique will work on layers that are of sub-micron thickness. Because their test layers are made using standard microelectronic fabrication techniques in Georgia Tech’s clean rooms, Sitaraman believes they accurately represent the conditions of real devices. These are representative processes and representative materials, mimicking the processing conditions and techniques used in actual microelectronics fabrication.

“As we continue to scale down the transistor sizes in microelectronics, the layers will get thinner and thinner,” he said. “Getting to the nitty-gritty detail of adhesion strength for these layers is where the challenge is. This technique opens up new avenues.”

The research has been supported by the National Science Foundation, and was reported in the March 30, 2012 issue of the journal Thin Solid Films.

Learn more about Georgia Institute of Technology at http://www.gatech.edu/.

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