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October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 1
mechanical protection for smaller, more fragile MEMS devicesimproved thermal dissipation capabilitiespotential for higher yield: devices are encapsulated early in the process, protecting them from contamination in dicing stepslower cost per device:package assembly, burn-in and final testing can take place in a massively parallel fashion
Package Burn Test DiceDo this
DiceTest
PackagePackagePackagePackage
TestTestTestTest
BurnBurnBurnBurn
TestTestTestTest
Not this:
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 7
reliability during thermal cycling is keyNeed to match thermal expansion coefficients as closely as possible
Good thermal matching Strain minimizationMechanical strain can become significant near edges for larger dies w/greater contact densityNeed elastically compliant interconnects: metal springs vs. organic elastomers
Conformal contacts between solder bump and wafer.Better electrical performance using “bump on polymer” (pic. on right)
PROPER MATERIALS CHOICE IS CRITICAL
source: Kulicke & Soffa
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 8
To allow• Drug delivery• Sensing• Mixing• Thermal control• Acceleration – etc.
Without compromising• Device performance• Sensing, signal processing and communication• Powering, including on-board batteries• Adhesion and performance of materials used
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 11
Another tool for packaging• Walls and polysilicon capping structures
Encapsulation
Sensors and Actuators A 134 (2007) 11–19A flip–chip encapsulation method for packaging of MEMS actuators using surface micromachined polysilicon caps for BioMEMS applicationsHrishikesh V. Panchawagh, Faheem F. Faheema, Cari F. Herrmann, David B. Serrell, Dudley S. Finch, Roop L. Mahajan
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 14
BiopolymerMorphology templates deposition of the cells
domain center
domainedge
Cells prefer certainmorphologies
By modifying surface texture, morphology and surface chemistry, there is the potential to modify interactions with biological systems, altering the performance and usability of medical devices.
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 16
5.2 GHz Differential LTCC Antenna and Balun for Biomedical System in Package (SIP) Application, A,. Shamim, G. Breznina, M. Arsalan, L. Roy, Antenna Technology: Small and Smart Antennas Metamaterials and Applications, 2007. IWAT '07. International Workshop on, 21-23 March 2007 Page(s):443 - 446
Powering and communication – some options• Inductively coupled loops, RF• Implantable batteries• Fuel cells• Optical methods…and with considerations of fluids and biocompatibility
Source: Steven S. Siliterman, BioMEMS and Medical Microdevices
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 18
Key reliability and quality standards for MEMS• Iso9000 series Principles for general quality management• IEEE 1332 Program for reliability of electronic systems• IEEE 1413 Methodology for reliability prediction• MIL standards If device for military use• GR standards If device has optical components• 21 CFR 800-1299 USFDA, Center for Devices and Radiological Health
Life testing• Accelerated life modelling/testing• Failure rate “bathtub”: infant mortality; constant random failures; wearout
And because it’s BioMEMS, test considerations include• Fluidics• Wireless• Biocompatibility• …
Source: Nadim Maluf & Kirt Williams, An Introduction to Microelectromechanical Systems Engineering
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 19
– Diabetes – Infectious diseases– Cardiovascular– Respiratory– Blood Pressure– Endoscopy “lab on a pill”– Dialysis monitoring
Some measurands:– Pressure (e.g. blood, or any bodily fluid of interest)– Exhaled gases (e.g. CO2, alcohol, O2, water)– Chemistry of interstitial fluid, blood, saliva, dialysate
Location (wireless comm. and power often useful):– At home, implanted, wearable– In doctor’s office, hospital
Epocal’s flex card, a smart microfluidic card for biosensor arrays. Uses Roll to Roll processing through to finished diagnostic card, with rapid throughput in manufacturing. From Mark Wendman’s blog
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 21
Sensors and Actuators A 126 (2006) 270–276; Parylene-strengthened thermal isolation technology for microfluidic system-on-chip applications; Chi-Yuan Shih, Yang Chen, Yu-Chong Tai
Advantages• Portability• Reduced size (and volumes)• Integration and automation• Potential for parallel analyses
Challenges• Small-scale physics• Everything is smaller• “World-to-chip” interfaces
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 23
Diverse packaging for pressure sensing applications
www.mesotec.com
Fluid interfaces and packaging vary according to wide-ranging needs
• “Simple” tubes on standard cans with damping• Implantable devices• Wireless power and communication• Flexible and/or transparent packaging• Pkg can include channels & manifolds
NovaSensor Device: Source: Nadim Maluf & Kirt Williams, An Introduction to Microelectromechanical Systems Engineering
CardioMEMS The EndoSure®sensor is approximately the size of a paperclip. It is a hermetically sealed circuit encapsulated in fused silica and silicone, and is surrounded by a PTFE-coated nickel-titanium wire. The sensor contains no batteries or internal power source, but is instead powered by RF-energy provided by a proprietary electronic antenna.
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 27
Codman® Hakim™ Programmable Valve (CHPV)Used for Hydrocephalus
The CODMAN® Programmable valve offers the ability to optimize the opening pressure of a shunt system before and after implantation. ... The programmable valve allows a surgeon to non-invasively change the opening pressure between 30mm H2O and 200 mm H2O in 18 steps; negating the need for revision surgery to alter the valve pressure. … The opening pressure … is changed through the use of an externally applied, codified magnetic field.
Surgeon can change valve set-point non-invasively with external magnet.
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 28
http://www.debiotech.com/debiotech.html• MEMS technology using Si and glass
biocompatibility• Precise control of nL volumes• Prevent under/overdosing and detect occlusions, other problems• Small size: 1/4th the size of existing monitors• Proprietary hermetic packaging• In the U.S. alone, 60 million people are affected by diabetes• 15% of worldwide health spending goes toward treating diabetes.• 450,000 people now wear transportable insulin pumps worldwide.
sources: Debiotech website; Advanced Packaging
Subcutaneous drug deliveryDebiotech piezoelectric insulin pump
Switzerland
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 29
Flexibility and durability are key for applications in the eye
Sensors and Actuators B 117 (2006) 107–114Scalable high lead-count parylene package for retinal prosthesesDamien C. Rodger, James D. Weiland, Mark S. Humayun, Yu-Chong Tai
October 22, 2008 MEPTEC October Workshop and Luncheon – SmallTech Consulting 30