Ultrasonic Systems, Inc....2014/04/16 · 4/16/2014 Ultrasonic Systems Inc. -Confidential 6 Fuel Cell Coating Process –Basic Requirements • Fuel cell coatings – Particles in

1Ultrasonic Systems Inc. - Confidential4/16/2014

Ultrasonic Systems, Inc.

Technology and Coating Systems


Company History

• Founded in 1989 with over 2,500 ultrasonic coating systems installed worldwide in the electronics assembly market

• Developed proprietary “nozzle-less” ultrasonic spray coating technology

• Spray fluxing product line introduced in 1991 (new models each succeeding year)

• Prism product line introduced in 2003 (fuel cell)• PV360 / FP920 introduced in 2009• PV480 / FP1200 introduced in 2010• MAX-800 introduced in 2011 (fuel cell)• Prism Bench top introduced in 2012 (fuel cell)


Applications• Fuel Cell

– Application of anode and cathode coatings onto electrolyte substrates• Solar

– Application of dopants to silicon wafers– Application of coatings to glass plates (thin film)

• Electronics Assembly– Application of conformal coatings to printed circuit boards– Application of fluxes to printed circuit boards

• Display– Application of photresists for touch panel display manufacture– Application of anti-reflective, anti-smudge, conductive layers and other very thin coatings

• Semiconductor Packaging– Photoresist to wafers– Polyimides– Silver or other metal coating to IC packages (EMI shield)

• LED Manufacture– Applying a phosphorous powder mixed with silicone to wafers

• Medical– Applying drug infused coatings to bandages and other substrates

• Batteries– Applying catalyst coatings to aluminum and copper foils

• Specialty– Applying proprietary coatings to lenses and other substrates


Fuel Cell Manufacturing


Fuel Cell Manufacturing• Fuel Cell

– Fuel can be hydrogen, methanol, ethanol, natural gas, diesel, etc.– Contains an anode, cathode & electrolyte

• Coating Process Focus– Application of anode and cathode layers to electrolyte surface– Application of hermetic seals for SOFC– Application of anode and cathode for electrolyzers

• Anode and cathode coatings– Typical solids content, 5 to 50%– Precious metal based (Pt or PtC) inks– Ceramic powder based slurries

• Electrolyte substrate types– Nafion membrane and carbon paper – Bi-polar/metal plates and ceramic plates– Ceramic tubes


Fuel Cell Coating Process – Basic Requirements

• Fuel cell coatings– Particles in suspension with carrier solvent– Carbon / precious metal based particles– Ceramics– Other proprietary mixtures

• Material handling– Need to keep coating material mixed– Need to deliver material at a controlled flow

• Coating process– Apply coating to the electrolyte substrate at a specific density– Flexible membranes must be held in place during coating– Coating layer must be uniform and defect free– Minimize cycle time to build layer


Nozzle-less Ultrasonic Coating Technology• Principle of Operation

– Spray is produced with ultrasonic energy– Spray is shaped with low pressure air flow

• Nozzle-Less Ultrasonic Spray Head– Coating applied directly to a rectangular spray forming tip on ultrasonic head with Liquid Applicator– Ultrasonic energy “atomizes” the coating liquid– Flat, “sheet-like” spray pattern is formed

• Integrated Spray Shaping – Air Directors– Independent air streams are used to expand the ultrasonically produced spray to a wider rectangular

pattern– Air flow through the air directors is adjustable to set the velocity of the spray

• Non-clogging Spray Head– Liquid delivery system does not clog– Spray shaping system does not clog

• Instant ON/OFF Spray Activation– Since liquid is applied directly to the ultrasonic tip, the spray can be activated and deactivated very quickly


Nozzle-less Ultrasonic Coating Technology


Ultrasonic Coating Technology

• Proprietary Coating Technology• Applies Thin, Uniform, Defect-Free Coating

– Coating Thickness: sub micron and up (depending on material properties, flow rate and number of layers applied)

– Transfer Efficiency: 95 to 99%– Spray Pattern: flat, rectangular shape from 2 mm to 150 mm (depending upon spray

head model)• Dual-Mode CAT-ILDS Ultrasonic Head

– Narrow Mode ( 2 to 5 mm pattern width)– Wide Mode (2 to 25 mm pattern width)– All parameters controlled by coating machine software

• CAT Blade Ultrasonic Head– 25 to 150 mm pattern width– All parameters controlled by coating machine software



ILDS Dual-Mode Head – major components



Blade Head – major components


Ultrasonic Coating Technology

Coating Head Operating Frequency

Pattern Width

CAT 35 ILDS Dual Mode 35 kHz 5 to 25 mmCAT 60 ILDS Dual Mode 60 kHz 2 to 15 mmStepped 60 Blade 60 kHz 25 to 150 mmCAT 35 Blade 35 kHz 25 to 150 mmCAT 45 Blade 45 kHz 25 to 150 mmStepped 35 Blade 35 kHz 25 to 150 mmStepped 45 Blade 45 kHz 25 to 150 mm





Ideal spray pattern:


Coating Distribution

0,00

1,00

2,00

3,00

4,00

5,00

6,00

Spray Nozzles

Nozzle-less Ultrasonicspray head


Nozzle-less Ultrasonic Coating TechnologySingle Pass Coating Application Sequence

Coating is applied to the substrate as a single layer with non overlapping coating segments

Coating segment

Spray pattern shape Substrate


Nozzle-less Ultrasonic Coating TechnologyInterleaved, Cross-hatch Coating Application Sequence



90 Degree Pneumatic Rotate

• 2-position rotate for CAT Dual-Mode Head and CAT Blade Head

• Designed for fast cycle times– rotates in 0.2 seconds

• Available on:– Prism 300 series– Prism Bench Top– MAX 800

• Ideal for fuel cell coating applications


Liquid Delivery Systems

• Purpose of a liquid delivery system– Deliver a controlled flow of coating liquid to the spray head– Store approximately 1 working shift worth of coating material– Keep a liquid with suspended particles mixed

• Types of liquid delivery systems– Pressurized systems

• Pressurized reservoir used to store liquid and set flow rate– Pump based systems

• Liquid pumped to spray head from a closed reservoir• Recirculating capable• Stirring capable

– Precision metering pump systems• Flow rate determined by motion of piston in a positive displacement pump• Piston motion is driven by servo motor• Internal liquid stirring inside the piston• Recirculating between the piston pump and coating reservoir


Liquid Delivery System

• PMP-100 Precision Metering Pump– Servo drive syringe pump designed specifically for fuel cell coating applications– 85 ml capacity piston– Integrated stirring – Automatic refill from liquid holding reservoir

• PMP-200 Dual Precision Metering Pump– Servo drive syringe pump– 100 ml capacity piston– Two pistons for continuous operation– Integrated stirring available– Recirculating available


Liquid Delivery System

PMP-100 Precision Metering Pump - Layout

Liquid Holding Reservoirwith Paddle Wheel Stirring

Linear Actuator and Servo Drive Motor

Syringe, Plunger withMagnetic Stirrer


Liquid Delivery SystemsDual PMP Schematic:


Fuel Cell Coating Process

Interleaved Cross-Hatch Coating Sequence:

• Stationary substrate installed on heated vacuum hotplate• PMP-100 liquid delivery with internal stirring to keep coating mixed• Successive coating layers applied in an interleaved, cross-hatch pattern• Carrier solvent evaporates completely between each coating layer applied• Coating layers applied until the desired loading or coating thickness is achieved• Substrates move on for further processing



Spraying Slurries with Ultrasonics

• Fuel cell slurries comprised of:– Carrier solvent– Suspended particles– Other ingredients

• Particles are entrained in sprayed droplets– Ultrasonic energy sprays solvent carrier liquid– Particles “go along for the ride”

• Ultrasonically produced droplets must be large enough to entrain slurry particles– 35 kHz ideal in most cases– Very high frequency ultrasonic energy not effective



Building Quality Layer

• Quality of layer– Uniform distribution– Smooth and defect free appearance– Solvent carrier evaporates

• Layer Build Process– Apply successive thin layers until required thickness is achieved– Solvent carrier evaporates between each layer application

• Objective– Build the layer as quickly as possible– Build a uniform and defect-free layer



Potential Problems with Layer Build

• Non-uniform layer– Non-uniform coating applicator

• Cracks or Bubbles in Layer– Layer applied too “wet”– Layer applied too thick– Solvent carrier evaporates through thick layer causing defects

• Layer not Smooth– Layer applied too “dry”– Slurry not properly mixed


Saint Gobain Corporation – Booth #C77

Application of hermetic seal layer to the SOFC stack

• Solid oxide fuel cell – all ceramic stack• A layer of slurry containing glass-ceramic particles is applied to the sides

of the fuel cell stack• The layer is sintered in a furnace to produce a “glaze” that acts as a

hermetic seal between the stack and the manifold• Hermetic glass surface seals eliminate the need to heavy compression

frames to maintain gas-tight operation

Solid Oxide Fuel Cell Manufacturer


Saint-Gobain’s co-sintered all-ceramic SOFC stack

Air and fuel gases are directed into the stack from the sides and flow through channels within the cathode and anode electrodes respectively. Due to this unique configuration, a hermetic seal must be applied to four faces of the stack. They are seen in this images as thin, reflective glass-ceramic coatings on the sides.

Two key requirements for the applied seal:1. Defect free ‘glaze’ to prevent gas from penetrating incorrect electrode2. Uniform thickness to enable a good mating surface between the gas

manifold and the stack


Sub-Scale Stack Performance

• Coatings applied with the USI system show excellent structural integrity and uniform thickness

• Defect-free seal yields high open circuit voltage

Hermeticity He leak rate (mbar

L/s.cm2)Porous anode 2,3.10-4

After seal is applied 5,6.10-10

Steel disk reference 9,4.10-10

Process Results – Saint Gobain SOFC


• Uniform coating thickness creates leak-free interface and thus high fuel utilization

• Flatter the fuel utilization curve the more efficient the stack

Non-uniform coatingcreates leaks betweenstack and manifold

Uniform coating prevents leaks between stack and manifold

Stac

k

Coa

ting

Man

ifold

Process Results – Saint Gobain SOFC


PEM Fuel Cell Manufacturer

• Coating process using interleaved cross-hatch sequence

• Membrane fixtured on vacuum hotplate• Loading requirement: 1.5 mg/cm2

• Actual loading achieved: 1.45 to 1.55 mg/cm2

99% of the time

Application of precious metal based catalyst to both sides of Nafion membrane (anode and cathode)


Prism Bench Top Coating System

• Lab scale coating system– R&D applications

• 3 axes of motion– XYZ, or XYZ w/ 90-degree rotate– Servo drive ball screw actuators

• 410 mm x 410 mm range of motion– 390 mm x 390 mm max coating area– 100 mm z axis range of motion

• Configured with 1 coating head• Windows based GUI

– Teach mode with laser pointer • Adjustable substrate fixture• Options:

– Precision metering pump (PMP) w/ integrated stirring– Research-grade syringe pump– Substrate heater w/ vacuum– 90-degreee head rotate


Prism Coating System Platform

• R&D and production applications• 3 or 4 axes of motion

– XYZ– XYZ-rotate

• 500 mm x 500 mm x 100 mm range of motion– 460 mm x 460 mm max coating area– Servo drive ball screw actuators

• Configured with 1 or 2 coating heads• Windows based GUI

– Teach mode with laser pointer• Options:

– Batch or in-line w/conveyor– Precision metering pump (PMP) w/ integrated

stirring– Substrate heater w/ vacuum– 90-degree head rotate– 4th axis (head rotate)– HEPA filters


MAX 800 Coating System Platform

• High-volume production applications• 3 or 4 axes of motion

− XYZ coordinated motion− XYZƟ

• 800 mm x 800 mm x 119 mm range of motion− 780 mm x 760 mm max coating area− Servo drive enclosed actuators− High speed capability up to 700 mm/sec

• Configured with 1 or 2 coating heads− Dual precision metering pump (PMP) liquid

delivery• Control system

− Programmable automation controller− Touch panel HMI− Joystick teach mode w/ laser pointer

• Options:− Batch or in-line w/ conveyor− Substrate heater w/ vacuum− Class 100 clean room− Active HEPA filtration− Customized substrate handling

Documents

Ultrasonic Systems, Inc....2014/04/16 · 4/16/2014 Ultrasonic Systems Inc. -Confidential 6 Fuel Cell Coating Process –Basic Requirements • Fuel cell coatings – Particles in