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Using Nanocoatings: Opportunities & Challenges for Medical Devices Cheryl Tulkoff, [email protected] Senior Member of the Technical Staff DfR Solutions November 12-13, 2013; Milpitas, CA.

Using Nanocoatings: Opportunities & Challenges for Medical Devices

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There is significant opportunity for improvements in contamination prevention, field performance and cost of medical devices through the use of biocompatible nanocoatings. To be successful using these coatings requires knowledge of the materials and processes on the market, the regulatory status, and the benefits versus risks. This presentation will provide a clear understanding of the current state of nanocoating technology for medical devices and electronics. There has been an explosion in new coating technologies over the past 24 months. The use of nanocoatings has been driven by the desire for moisture proofing, providing an oxygen barrier ( a hermeticity option) and mitigating tin whiskers. Successful adoption of these coating technologies can lead to improved performance and market differentiation. Inappropriate adoption can drive higher failure rates, recalls and alienation of customers. Obtaining relevant reliability and quality information can be difficult. The information is often segmented for different markets; and, the focus is on the opportunities, not the risks. The primary information sources are either marketing material or confusing, scientific studies. Where is the practical advice?

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Page 1: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Using Nanocoatings:

Opportunities & Challenges for

Medical Devices

Cheryl Tulkoff, [email protected]

Senior Member of the Technical Staff

DfR Solutions

November 12-13, 2013; Milpitas, CA.

Page 2: Using Nanocoatings: Opportunities & Challenges for Medical Devices

• Introduction

• What is nanocoating technology?

• Super Hydrophobicity

• Atomic Layer Deposition

• Multi-Layer Barrier Films

• Who are the key players?

• What are the benefits?

• What are the risks?

• Summary

Topics to be covered

Page 3: Using Nanocoatings: Opportunities & Challenges for Medical Devices

What is a medical device?

3

More diverse group than medical

electronics!

Page 4: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Medical Device Definition Surprisingly, no good, uniform definition of a medical device

Increasing overlap in technologies combining medical devices with biologics or drugs.

Example: Drug-coated stents. How the device is regulated depends upon the primary function of the

product

Since the stent is performing the primary function of holding a blood vessel open, it is regulated in the US as a medical device

If the primary function was to deliver medication, it would be regulated as a drug

This is an extremely complex area of regulation!

Page 5: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Medical Electronics – Still very

diverse!

Page 6: Using Nanocoatings: Opportunities & Challenges for Medical Devices

What are medical electronics?

Is it a realistic category? Some implanted in the body; some outside

Some portable; some fixed

Some complex; some simple

Some control; some monitor; some medicate

All connected by the perception that one’s life may be dependent upon this product Creates a powerful emotional attachment/effect

Assuring reliability becomes critical

Page 7: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Why are medical coatings used?

Enhance performance of the device Extend useful life

Cleaning, disinfection, and sterilization protocols degrade product

Protect the device Human body is a hostile environment

Protect the patient Body responds to intrusions

Defense mechanisms treat foreign objects as threats

Reduce scar tissue and infection opportunities

Encourage/enhance healing

Page 8: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Medical Coating Challenges

Biocompatibility

Coating adhesion

Uniform coverage over challenging shapes

Strength

Durability

Page 9: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Parylene-N and -C are currently approved by FDA as a USP class VI polymer Allows them to be used in biomedical devices

Parylene-C has higher thermal stability & chemical/moisture resistance than Parylene N Commonly chosen as an encapsulation material for

biomedical devices

Applications include stents, pacemakers, neural probes, and solder joints encapsulation

CVD Parylene can form a conformal and pinhole free coating Parylene films do not have strong adhesion to inorganic surfaces

such as silicon

State of Coatings in Implanted

Medical Devices

Reference” Characterization of Parylene-C film as an encapsulation material

for neural interface devices”

Page 10: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Nonfouling (protein adsorption-resistant) thin-layer polymeric coatings offer more paths to reduce inflammatory responses Surface coatings that completely eliminate protein adsorption

over the lifetime of a device have not been found

Design requirements for implanted materials and devices vary considerably Depends on the application and site of implantation

Polymeric surface coatings for implantables ideally conform to the following: Use nontoxic materials

Prevent biofouling

Can be deposited on a variety of materials and architectures

Mechanical, chemical, and electrical stability to withstand surface deposition, sterilization methods, implantation procedures, and in vivo environment

Medical Device Coating Needs

Page 11: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Nanocoating Introduction Explosion in new

coating technologies

over the past 24

months

Drivers

Moisture proofing

Oxygen barrier

(hermeticity)

Tin whiskers

Page 12: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Super Hydrophobicity

Atomic Layer Deposition

Multi-Layer Barrier Films

Nanocoating Technology

Page 13: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Definition: Wetting angle far greater than the 90 degrees typically defined as hydrophobic Can create barriers far more

resistant to humidity and condensation than standard conformal coatings

How to get there? Deposit materials with existing high surface tension

(e.g., Teflon)

Replicate the surface of the Lotus Leaf

Super Hydrophobicity

Page 14: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Three companies currently focused on the

electronics market

The key technology for each company is

the process, not necessarily the materials

Nano Deposition of High

Surface Tension Materials

Page 15: Using Nanocoatings: Opportunities & Challenges for Medical Devices

GVD: Founded in 2001. Spinoff from MIT Key technology is initiated chemical vapor deposition

(iCVD) and PTFE and Silicone

P2I: Founded in 2004. Spin off from UK MOD Laboratory and Durham University Key technology is pulsed plasma and halogenated

polymer coatings (specifically, fluorocarbon)

Semblant: Founded in 2009. Spin off from Ipex Capital Key technology is plasma deposition and halogenated

hydrocarbon

Nanocoating Companies

Page 16: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Hydrophobicity tends to be driven by number and length of the fluorocarbon groups and the concentration of these groups on the surface

The key points to each technology are similar All assisted chemical vapor deposition (CVD) processes

Room Temperature Deposition Process

Low Vacuum Requirements

Variety of Potential Coating Materials (with primary focus on fluorocarbons)

Differentiation is how they breakdown the monomer before deposition

Process Technology

Page 17: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Process Differentiation

iCVD uses a chemical initiator to breakdown the monomer

Plasma-Enhanced CVD (PECVD) uses plasma to breakdown the monomer

http://web.mit.edu/gleason-lab/research.htm

Courtesy of Semblant Ltd.

Page 18: Using Nanocoatings: Opportunities & Challenges for Medical Devices

These are truly nanocoatings Minimum Parylene thickness tends to be above

one micron (necessary to be pinhole free)

These coatings can be pinhole free at 100 nm or lower

Nanocoating allows for Optical Transparency

RF Transparency

Reworkability

Elimination of masking

Benefits (especially compared

to Parylene)

Page 19: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Optically Transparent

Courtesy of P2i

Page 20: Using Nanocoatings: Opportunities & Challenges for Medical Devices

LLCR Measurements

Current (A) 0.01

V comp (V) 0.1

Connector Male 34way Pin Header Au over nickel contact (TE Connectivity 1-215307-7)

Connector Female 34way Socket Header Au over nickel contact (TE Connectivity 1-826632-7)

Benefits: No Masking

1 2 3 4 5 6 7

32 33 34

Current

Source

10mA

Nano

Voltmeter

34 way

header pins

34 way

header Socket

Rcontact = Vmeasure/10x10-3

Test Circuit

0

1

2

3

4

5

6

7

8

9

0 10 20 30 40

Re

sist

ance

(m

Oh

ms)

Pin Number

Low Level Contact Resistance

Plasma Coated

Uncoated

Courtesy of Semblant Ltd.

Page 21: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Voltage Breakdown Levels tend to be lower compared to existing coatings (acrylic,

urethane, silicone)

Can be an issue in terms of MIL and IPC specifications

Optically Transparent Inspection is challenging

Cost Likely more expensive than common wet coatings

However, major cell phone manufacturer claims significant ROI based on drop in warranty costs

Throughput Batch process. Coating times tend to be 10 to 30 minutes, depending

upon desired thickness

However, being used in high volume manufacturing

Risks?

Page 22: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Nanocoating technology is being used by

almost every major hearing aid

manufacturer (8 million per year)

High Volume Manufacturing

Courtesy of P2i

Page 23: Using Nanocoatings: Opportunities & Challenges for Medical Devices

P2i combats contamination and costly sample loss through coatings for medical devices & laboratory equipment

Semblant developed Plasma Shield, a conformal coating to coat electronic components for internal medical devices and equipment

GVD provides protective coatings for medical electronics, biocompatible coatings on implantable devices, & lubricious coatings for tubes and trocars.

Manufacturing for Medical

Page 24: Using Nanocoatings: Opportunities & Challenges for Medical Devices

High aspect surfaces create very high (>150o) wetting angles

Rapid adoption in other industries Paints, clothing, etc.

Challenges with electronics Different surfaces/chemistries can

disrupt surface modification

Where are Lotus Leaf

Coatings?

Page 25: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Developed in the 70s and 80s

Sequential surface reactions

Deposition rate of ~0.1 nm/cycle

Atomic Layer Deposition (ALD) Deposit

organometallic /

hydroxyl compounds

Purge

Treatment to react 1st

precursor (2nd

precursor or energy)

Purge

Page 26: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Designed for inorganic compounds Primarily simple

oxides and nitrides

Limited industrial acceptance Electroluminescence displays (obsolete)

Basic research

Glass strengthening

Considered for next-gen silicon

Interest from solar

Moisture / oxygen barriers

ALD (cont.)

Page 27: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Advantages Deposition at low temps

(80-150C)

Not line of sight (conformal)

Precise thickness control

Large area

Less stringent vacuum requirements (0.1 – 5 mbar)

Multilayer and gradient capability (it can be tailored)

Northrop Grumman / Lockheed Martin estimated cost reductions of 50% vs. traditional hermetic approaches

ALD (cont.)

Atomic Layer Deposition (ALD) Coatings for Radar Modules, DMSMS 2012

Page 28: Using Nanocoatings: Opportunities & Challenges for Medical Devices

The process can be very slow (100nm thickness can take over an hour)

Not reworkable

There have been challenges in regards to compatibility of ALD with existing electronic materials and manufacturing process Clean surfaces with similar coefficient of thermal

expansion (CTE) work best

De-adhesion and cracking sometimes observed when applied to metals, polymers, and surfaces with flux residue (requires some tailoring)

Risks

Page 29: Using Nanocoatings: Opportunities & Challenges for Medical Devices

A Multi-Layer Barrier Stack to retard water vapor and oxygen diffusion Patent history includes

Osram, filed in 2001

Similar patents filed by Battelle Labs and commercialized by Vitex Systems in 1999 (Barix) (now Samsung America)

Flexibility and transparency key attributes of the technology Index matching of materials (primary driver is organic

LEDs and thin film solar)

Multi-Layer Barrier Films: What

is the Technology?

Page 30: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Oxide barrier layer protects against oxygen and moisture Can be aluminum oxide, silicon oxide, or silicon nitride

Polymer layer provides adhesion, smooth surface, decouples defects Three to four layers required to survive 60C/90%RH for 500 hrs.

Requires permeation less than 10-6 g/m2/day

Multi-Layer Barrier (cont.)

3 um total thickness

Page 31: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Requires a low temp vacuum deposition process (PVD or CVD) Concerns about cost and throughput (similar to parylene)

Multi-Layer Barrier Manufacturing Process

Vitex Process

Page 32: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Recent advances use nanotechnology to

eliminate defects

Nanoparticles seal defects

and react/retain oxygen

and moisture

Requires fewer layers to

be effective

Claims up to

2300 hours

at 60C/90%RH

Multi-Layer Barrier Advances

Page 33: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Multi-layer barrier is believed to be the only solution for OLEDs However, commercialization has been limited

Developed over ten (10) years ago; still not in commercial production

Only one or two manufacturers in this space

Cost could be high (similar to parylene) and potential for low throughput (batch process)

Rework is likely impossible

Risks

Page 34: Using Nanocoatings: Opportunities & Challenges for Medical Devices

There is significant opportunity for field performance improvement and cost reduction through the use of nanocoatings

Requires a knowledge of the materials and processes on the market Benefits vs. Risks

With any new technology, do not rely on standard qualification tests! A physics-based test plan provides the most robust

mitigation

Conclusion

Page 35: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Presenter Biography

Cheryl has over 22 years of experience in electronics manufacturing focusing on failure analysis and reliability. She is passionate about applying her unique background to enable her clients to maximize and accelerate product design and development while saving time, managing resources, and improving customer satisfaction.

Throughout her career, Cheryl has had extensive training experience and is a published author and a senior member of both ASQ and IEEE. She views teaching as a two-way process that enables her to impart her knowledge on to others as well as reinforce her own understanding and ability to explain complex concepts through student interaction. A passionate advocate of continued learning, Cheryl has taught electronics workshops that introduced her to numerous fascinating companies, people, and cultures.

Cheryl has served as chairman of the IEEE Central Texas Women in Engineering and IEEE Accelerated Stress Testing and Reliability sections and is an ASQ Certified Reliability Engineer, an SMTA Speaker of Distinction and serves on ASQ, IPC and iNEMI committees.

Cheryl earned her Bachelor of Mechanical Engineering degree from Georgia Tech and is currently a student in the UT Austin Masters of Science in Technology Commercialization (MSTC) program. She was drawn to the MSTC program as an avenue that will allow her to acquire relevant and current business skills which, combined with her technical background, will serve as a springboard enabling her clients to succeed in introducing reliable, blockbuster products tailored to the best market segment.

In her free time, Cheryl loves to run! She’s had the good fortune to run everything from 5k’s to 100 milers including the Boston Marathon, the Tahoe Triple (three marathons in 3 days) and the nonstop Rocky Raccoon 100 miler. She also enjoys travel and has visited 46 US states and over 20 countries around the world. Cheryl combines these two passions in what she calls “running tourism” which lets her quickly get her bearings and see the sights in new places.

Page 36: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Instructor Biography

Cheryl Tulkoff has over 22 years of experience in electronics manufacturing with an

emphasis on failure analysis and reliability. She has worked throughout the electronics

manufacturing life cycle beginning with semiconductor fabrication processes, into printed

circuit board fabrication and assembly, through functional and reliability testing, and

culminating in the analysis and evaluation of field returns. She has also managed no clean

and RoHS-compliant conversion programs and has developed and managed

comprehensive reliability programs.

Cheryl earned her Bachelor of Mechanical Engineering degree from Georgia Tech. She is a

published author, experienced public speaker and trainer and a Senior member of both

ASQ and IEEE. She holds leadership positions in the IEEE Central Texas Chapter, IEEE

WIE (Women In Engineering), and IEEE ASTR (Accelerated Stress Testing and Reliability)

sections. She chaired the annual IEEE ASTR workshop for four years and is also an ASQ

Certified Reliability Engineer.

She has a strong passion for pre-college STEM (Science, Technology, Engineering, and

Math) outreach and volunteers with several organizations that specialize in encouraging

pre-college students to pursue careers in these fields.

Page 37: Using Nanocoatings: Opportunities & Challenges for Medical Devices

Contact Information

• Questions?

• Contact Cheryl Tulkoff,

[email protected],

512-913-8624

[email protected]

• www.dfrsolutions.com

• Connect with me in LinkedIn as well!