Fundamentals of Microsystem Packaging Presented by: Paul Kasemir Ideen Taeb Chapter 3 Role of Packaging in Microsystems What is an Electronic Product? Examples 1. Computer 2. Telecommunication 3. Automotive 4. Medical and Consumer Anatomy of a Microsystem Systems Packaging PWB/PCB Physical Analog Digital RF Photonic ICs MEMS Microsystem Classification There are 6 categories Automotive Computer and Business Communications Consumer Industrial and Medical Military and Aerospace 4.8% 38.6% 26.1% 11.3% 10.6% 8.7% Components of a Cell Phone Computers and the Internet Computers are the backbone of the Internet E-business Server farms handle e-business information Streamline internal business and engineering Employee communications External relationships Evolution of Computers 1st Computer: The Eniac 18K vacuum tubes Von Neumann’s Architecture 1945 Presents basic digital stored-program computer Unix in the late 1960s DOS in 1981 Windows 3.1 in 1994 Windows 95/98/NT Networked Computers Client-Server networks Simple low cost clients Potential high speed computer networks Remotely “booted” Example Uses Customer support Finance Manufacturing Role of Packaging in Computers Migrate from vacuum tubes to transistors and finally to integrated circuits (ICs) Bandwidth is the most important parameter in computing Frequency times parallel operations equals computing power More computing power means more heat produced, and needs packaging to cool How Do Computers Work? Microprocessor (uP) computes data I/O subsystem feeds instructions and data to the microprocessor Computer System Performance Performance is measured in MIPS (Millions of Instructions Per Second) Component of performance: Microprocessor speed Instructions per cycle (MIPS/MHz) Microprocessor utilization Perf = (Speed) (MIPS/MHz) (Utilization) Bandwidth and Performance Bandwidth measured in bits per second b/s A 64 bit wide bus at 100MHz clock (using both up and down edges) has 12.8 Gb/s Memory that uses both edges is termed doubledata-rate DDR Bus Bandwidth affects cache fill rate Latency is also critical Too many requests to memory will introduce many wait cycles Packaging and Performance Packaging enables good bus performance Wide busses Put L2 cache on chip Packaging is crucial for cooling the uP Copper heat sinks and heat pipes Packaging and Bus Design High via and wire densities High dielectric constants High propagation speeds Low capacitance Thin layers and many power planes Lower noise Good power distribution Example Intel’s IA-64 Itanium Multiple caches Efficient Heat Sink Role of Packaging in Telecommunications Communications have become much more complex recently Used to have different media for different types of communication Voice on the phone line Images on the TV Data on computers Multimedia Combination of multiple types of content into the same message format Content has different requirements Voice needs low delay Data needs perfect accuracy Packet switching technology guarantees quality of service Fiber optical cable provide high bandwidth for multimedia communications Mobile Phones Market is increasing very fast Wireless Communications Bandwidth for wireless is much smaller Mobile phone sizes are shrinking 1985: 1000g 1990: 350g Cell Phones Required components for the phone Radio frequency/intermediate frequency (RF/IF) Analog-to-digital (A/D) and digital-to-analog (D/A) converters Digital signal processing hardware Power and battery management Transmit/Receive Chain Baseband Section CMOS technology used in DSPs Can reduce the number of ICs Can reduce the weight and size with system-on-package (SOP) RF Section Uses many materials such as silicon, silicon germanium or gallium arsenide CMOS and bipolar technology 100s of passive components for filters and oscillators These make size reduction in the RF components difficult Battery and Weight Long battery life is important Monitor the health of battery Charge when plugged in Power digital and analog circuits of battery Weight is reduced by shrinking the PCB size and lowering the IC count Surface Mount Devices (SMD) lower power, weight and size Role of Packaging in Automotive Systems Automotive industry is as big as electronic industry. It accounts for less than 5% of total equipment sales. Growing in size every year Electronic Content In year 1998, each vehicle had $843 worth of electronics. Wires and connectors and buses plays a major role in Automotive electronics Wiring and connectors account for 49% of the average North American electronic today In ten years, it will only drop to 44% Electronics in Automobile Primary Characteristic of Automotive is Harsh Environment Temperature plays a big role in Automotive Industry For example, under the hood temperature can be as low as -40 deg C. And right after starting the car, it can get as high as 204 deg C This harsh temp environment is combined with humidity, vibration and etc. Engine Compartment Thermal Profile Electronic Packaging Technologies Three Different Technology Substrate Technologies Assembly Technologies System-Level Packaging Technologies IC and System Substrate Technologies Three different substrates are used in automotive electronics: Organic, Ceramic and insulated metal Organic Packaging Technologies(FR-4) Most widely used substrate Includes many layers Substrates with higher glass are emerging for higher temperature and communication-related automotive applications New generation with caps and resistors embedded in the layers thus avoiding discrete components Ceramic Packaging Technologies Alumina is most commonly used ceramic Laser trimmability of the thick film resistors to obtain precision values is an attractive feature of this technology. Other examples are: HTCC, LTCC In those, embedded passives are also available Aluminum nitride used for thermal management Ceramic Packaging in Automotives Metal Packaging Technologies Insulated with a dielectric layer on which the circuitry is built. More advantages in thermal management, and geometric Assembly System-Level Packaging Technologies Two different methods: Housing Techniques Passivation/Conformal Coating Housing Technique Includes die-cast aluminum, die-cast plastic and sheet metal. Wire-bonding and direct-solder-attach are used to provide interconnection from the circuit to substrate Passivation/Conformal Coating Can be done at substrate or at final assembly Materials used: acrylics, epoxies, urethanes, silicones and parylenes Implantable Electromedical Devices Widely used today: hearing aids, heart pacemakers … Developing in neurological: IPGs can used to stimulate the spinal cord or the brain directly to alleviate chronic pain. Need to be reliable!!!! Decreasing in size: ICDs from 120cc to 30cc Implantable Cardiac Defibrillator Microsystem Play a Dominant Role in Medical Electronics Simple cardiac device can function: Sensing the heart’s electrical activity Sensing the motions and activity level of the patient Sensing the blood flow to and from the heart and etc These functions require low-voltage microprocessors,AD and AD converters and more functioning blocks Packaging will put all these in small chip or device. Role of Packaging in Consumer Electronics US Consumer Electronic Products and Volumes Characteristics of Consumer Products Production is in the millions of units per year Product life cycles are often short and production ramp ups are fast Designs tend to be stable during the product run Product categories tend to saturate their available market very quickly, so the industry is always looking for the next application Brutal and sustained cost reduction, favoring the oldest technology that will do the jobs unless the small factor is critical Role of Packaging in Micro-Electromechanical systems(MEMS) products What are MEMS? Benefits of MEMS MEMS play a major role in Medical Electronics MEMS applications What are MEMS? Key to further development of the industrial, medical, and control industry. Combines electrical functions and the micromachined elements to form a system-onchip(SOC) or system-on-package(SOP) Compromised of microprocessor circuitry and mechanical functions Can be mass produced Benefits of MEMS Can be used in nearly every industry Have a beneficial cost, size and reliability MEMS play a major role in Medical Electronics 20 million microscopic pressure sensors are used each year in blood pressure measurement Many different applications such as micropumps MEMS Applications Used in measurement of gravity to determine orientation tilt and inclination Measurement of velocity and position Measurement of vibration and shock Automobile industry: braking systems, accelerometer MEMS market currently in excess of $5 billion Summary and Future Trends Summary and Future Trends Digital performance of the order of 10 GHz digital computer clock speed RF performance of the order of 100 GHz RF/wireless speed Optical performance of the order of 10 terabit per second Summary and Future Trends IC I/Os to be packaged in Various Systems