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© 2015 TechSearch International, Inc.

IoT and the Impact on MEMS and Sensors Packaging

E. Jan Vardaman President and Founder

TechSearch International, Inc.

www.techsearchinc.com


What is IoT?

•  Internet of Things…..Cisco’s Internet of Everything

•  IoT means connectivity – More than just WiFi – Does the growth of IoT increase the demand for

MEMs and Sensors? – What special packages are required for MEMS and

Sensors in Connected Devices?


Connected Device Market: It’s Growing

•  Market growth for connected devices according to Cisco •  Morgan Stanley wearable electronics growth rate of 154% •  Shipments projected to increase from 6 million units in 2013 to

248 million units in 2017


Growth Drives MEMS and Sensors

•  MEMS and sensors growth driven by growth in wearable electronics •  Many different packages for wearable electronics


IoT: More Than Just a Watch or Fitness Band!

•  Collection data •  Monitoring data •  Storing data (medical

record, mobile payment information, industrial info, driving data, insurance data, etc.)

•  Analyzing data •  Yes, IoT means

connectivity •  Yes, and keeping data

secure

Source: Progressive.

Progressive Snapshot Morgan Stanley reports over 6 years 10 billion miles worth of driving data (100+ terabytes) collected


MEMS and Sensors for Connected Devices

•  Accelerometers and Gyroscopes for motion sensing

•  Pressure sensors •  High precision light sensors to accurately

measure blood flow •  Sensors to accurately calculate heart rate •  Blood pressure monitors (need higher

accuracy) •  Glucose monitoring •  Pulse monitors for runners etc. •  Others…….. •  But, sensors have to function properly!!

–  Many examples of heart rate or blood pressure sensors that don’t measure accurately

–  Limits product adoption: “Users will stop using the devices and enterprises will not adopt the technology if data is not accurate”

MEMS Accelerometer STMicroelectronics


Low-Power Optimized MCU for Fitness Band

•  Trade-off in design is power vs. performance •  Processor is constantly analyzing data from sensor •  Device does not get to go into “sleep mode” •  Improved battery life becomes key to product success

Bluetooth LE!transceiver System logic

Sensor subsystem

UART

GPO

USB!host/!OTG

Timers

NVM/!SRAM

ADC/!DAC

CPU

I2C SPI

Sensors• Accelerometer!• Compass

• Heart rate!• Gyroscope

MCU

Customer/!third-party IP

Other!DesignWare IP

ARC and!subsystem IP

Source: Synopsys via Semiconductor Engineering


Recent MEMS Developments

•  Wafer level technology being adopted –  Cavendish Kinetics with its RF MEMS tuning solution for LTE

smartphones and wearable devices using STATS ChipPAC WLP for small form factor

–  Die thickness after back grinding 0.39 mm –  Total package height + solder ball 0.55 mm –  Lead count of 9 –  2X higher data rates and improved battery life (40%) –  Future RF antenna developments

•  TSMC developments in MEMS –  SoC and MEMS in one chip (CMOS integration, deposition of

material on top of silicon) –  Last year accelerometer (motion sensor) –  This year pressure sensors –  Future gyroscope –  Future monolithic microphone


Apple’s Watch Board and Packages

•  Almost no leadframe packages •  Mostly area array packages

–  FBGAs –  WLPs

•  Expected to use WiFi module with WLP •  No board space available: Need greater use of WLP or System-in-Package (SiP)

Source: Apple.


Sensor Examples in Apple’s Watch

•  STMicroelectronics digital gyroscope and accelerometer

– Reported by Chipworks to be packaged in 3mm x 3mm LGA

–  6 axis sensor in a single component

– MEMS sensor and control ASIC stacked together

– Wire bonded •  STMicroelectronics optical

emitter/sensor encoder die •  Knowles microphone

Source: Apple.


System-in-Package: Key to Connected Devices •  Apple Watch SiP reported by

Chipworks to have >30 components –  Some multiple die such as PoP –  Package is only 26 mm x 28 mm –  Overmolded

•  Renesas and Link Labs radio module for machine-to-machine communication

–  Renesas microcontroller –  Semtech long distance radio

transceiver –  Applications including security

monitoring, agricultural monitoring, home automation, smart meters

•  Samsung Electronics Artik modules –  Contains processors, memory,

communication chips, and software

–  All essential elements for connected gadgets

Source: Samsung.


Medical Connected Devices

Source: IPDiA.

•  Traditional medical implantables

•  From fitness accessory to clinical tool

•  Wearable technology to help senior citizens remain mobile and live independent lives

•  Non-invasive wearable transdermal microsystems for continuous monitoring

•  Textiles for muscle stimulation, continuous ECG monitoring, etc.

•  Wearables with sensors for targeted clinical applications in disease treatment


No One Package Solution Fits All! •  Packaging options (found in today’s products)

– BGA, FBGA – Flex circuit CSP – LGA (including MCM) – Chip-on-board (COB) – PoP – Stacked die CSP – Leadframe packages such as QFN, SOP, TSOP – Ceramic packages – Integrated passive devices – WLP – Embedded die – SiP

•  Packaging options (emerging) –  FO-WLP –  MIS package (leadframe versions with mold compound

as underfill and substrate) •  Cost/Performance trade-off determines adoption, but Cost

and Form Factor are key


MEMS Package Requirements

•  Specialized interface with outside world and exposure to corrosive gases or fluids such as pressure sensors, fluidic devices

•  Vacuum packaging, hermeticity •  Protection from moisture-sensitive capacitive devices

will get signal errors •  High-temperature operation, such as in-cylinder

pressure sensors operating at 1,000°C •  Challenging assembly processes, such as wire bonding

to vertical surfaces •  Sensitivity to vibration and shock during processing

steps such as grinding or pick-and-place


MEMS Packaging Complexity Many options and cost / performance considerations

Cavity or overmold?

Wire bond or flip chip?

Die attach method?

EMI shielding?

Laminate or leadframe?

Wire type, loop radius and gage?

Molded-in stress?

Leaded or not?

Encapsulation? Green material?

Stacked die or side-by-side?

How/what to test?

Source: Amkor Technology


Amkor MEMS & Sensor Packaging Evolution

DLP® courtesy of TI

Broad range of point solutions

Focused platforms

Transition from Custom Packaging to

High Volume Manufacturing

ChipArray® -Cavity

MLF® -Cavity (in-line or FAM)

ChipArray® -Molded

MLF® -Molded

LF-Cavity (pre-mold or FAM)

WLCSP

Source: Amkor Technology


MEMS Reliability •  Failure modes and mechanisms are more complex •  Number of potential failure modes and mechanisms is

larger •  Some failures, such as collisions or sticking of movable

parts, are transient and thus hard to identify or locate •  Packages contain multiple components and MEMS

device failure must be differentiated from an ASIC failure

•  Failure criteria are device- and application-specific •  Standard destructive failure analysis can result in

erroneous conclusions due to sample preparation problems, therefore physical analysis must often b combined with modeling to identify the most probable failure sites

•  Monitoring instruments may be exposed to the loading conditions, such as temperature excursions, mechanical shock, or vibration, and may need to be checked for degradation themselves


Connected Device Product Requirements?

•  What are reliability requirements? –  Lifetime? –  Environmental exposure (UV light, sweat,

stress, washer/dryer, cleaning fluids, mud, dust, wafer, sunscreen, etc.)

•  Fitness activity bands –  Polymer encased electronics –  Components must survive mold process

temperatures –  Must withstand twist, bend, flex compression –  Must not react with bodily and environmental

fluids •  Need special reliability tests

–  Drop test (is it shock proof?) –  Thermal stress (simulation) –  Is it moisture resistant?


Conductive Fabrics •  Knitting or weaving conductive threads into textiles

–  Metalized threads with allow of silver, copper, tin, nickel –  Deposition or coating of conductive polymers –  Printing conductive inks –  UK’s NPL development of stretch nylon fabric processed using its

technology (nano-silver coating of fibers)

Source: NPL.


Conclusions

•  Many different products

•  Many different package types (traditional MEMS packages vs. new packages required for connected products)

•  May need new reliability tests

•  May need new materials to achieve realization of future product designs

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