Momentive Silicone Conformal Coating Overview

Silicone Conformal Coating Introduction

Conformal Coating Overview
Conformal coatings are materials applied in thin layers (typically a few mils or a fraction of a mm)
onto printed circuits or other electronic substrates. They provide environmental and mechanical
protection to help significantly extend the life of the components and circuitry. Conformal coatings are
traditionally applied by dipping, spraying or simple flow coating, and increasingly by select coating or
robotic dispensing.
Conformal coatings protect electronic printed circuit boards (PCB) from moisture and contaminants,
help to prevent short circuits and corrosion of conductors and solder joints. They also minimize
movement of ions in a conductor (Electro-Migration). In addition, the use of conformal coatings
protects circuits and components from abrasion and solvents. Stress relief is also provided, as well as
protection of the insulation resistance of the circuit board.
A coating surface also helps insulate conduction paths between components by helping to block
humidity (insulation resistance)
Momentive conformal coating
under black light.
Copyright © 2017 Momentive Performance Materials Inc. All rights reserved.

Momentive Conformal Coating Product
Typical Physical
Properties
Legacy Grades Corrosion Resistance
Improvement Grades
Heat Cure Room Temperature Cure Room Temperature Cure
ECC4685 ECC3010 ECC3050S ECC3011 ECC3051S
Polymer Type Silicone Rubber Silicone Rubber Silicone Rubber Silicone Rubber Silicone Rubber
Components 1 Part 1 Part 1 Part 1 Part 1 Part
Color Clear Clear Clear Clear Clear
Viscosity (Pas) 0.25 0.11 0.55 0.11 0.55
Solid Content 100% 100% 100% 100% 100%
Solvents None None None None None
Specific Gravity 0.98 0.99 0.98 0.99 0.98
Tack Free Time at 23ᵒC (min) - 3 (at100um) 5 (at100um) 3 (at100um) 5 (at100um)
Cure Time (min) 15 (at105ᵒC) 10 (at 23ᵒC) 30 (at 23ᵒC) 10 (at 23ᵒC) 30 (at 23ᵒC)
Hardness (Type A) 35 (shore A) 35 22 35 22
Dielectric Strength (KV/mm) 20 20 20 20 20
Volume Resistivity (MΩ.m) 5.0 x 106 1.0 x 107 1.0 x 107 1.0 x 107 1.0 x 107
Salt Spray Result* - - - Good Good
Mixed Gas Test Result** - - - Good Good
IPC –CC-830B Status - - - Good Good
*IEC60068-2-52 Severity 5 **IEC60068-2-60 Method 4
New
ECC3011 & ECC3051S are new grades that utilize a proprietary technology to further help Momentive material
to prevent the occurrence of PCB corrosion under harsh operating conditions.
Typical properties are average data and are not to be used as or to develop specifications.

Conformal Coating Comparison
Momentive Products:
Manufactured to be solvent-free and
fast cure with no curing process & equipment
Typical properties are average data and are not to be used as or to develop specifications.
Physical Properties Comparison Table
Product A Product B Product C Product D ECC3011 ECC3051S
Maker Competitor A Competitor A Competitor A Competitor B Momentive Momentive
Parts 1-Component 1-Component 1-Component 1-Component 1-Component 1-Component
Polymer Polyurethane Polyolefin Acrylic Silicone Silicone Silicone
Color Clear Clear Clear Clear Clear Clear
Viscosity (Pas) 0,18 0,185 0,025 0,75 0,11 0,55
Solid Content 44% 22% 15% 72% 100% 100%
Solvents Toluene, Butanone Cyclohexane Butyl Acetate Toluene Solvent Free Solvent Free
Solvent Content 56% 78% 85% 28% 0% 0%
Tack Free Time at 23 ᵒ
C (min) 15 (at 75um) 10 (at 75um) 30 (at 75um) 7 (at 100um) 3 (at 100um) 5 (at 100um)
Tack Free Time at 60 ᵒ
C, 15% (min) - - - 2 (at 100um) 1 (at 100um) 2 (at 100um)
Cure Time (at 23 ᵒ
C) 720 Hours (30 Days) 24 Hours 24 Hours 10 min 30 min.
Hardness 　(Type A) - - - 80 35 22
Dielectric Strength (KV/mm) - - - 16 20 20
Volume Resistivity (Mohm.m) 2.0 x 106
2.0 x 106
5.5 x 106
5.0 x 105
1.0 x 107
1.0 x 107

Momentive Solvent-Free Formulation
Momentive Conformal Coatings are manufactured to be 100% solid content (solvent-free)
Unlike many available conformal coating materials that are highly solvent borne, Momentive employs a
solvent-free design in its products. This not only eliminates harsh solvents from the product, but allows
Momentive´s coating to be easily applied in one pass to achieve a thickness of >50um, which helps to
ensure that an adequate protective layer remains on the PCB.
PCB
100um
PCB PCB
50um
PCB
100um
PCB
100um
Solvent Type (non-Momentive)
Solvent-Free Type (Momentive)
applied thickness solvent escape thickness (after)
applied thickness thickness (after cure)

Coating Material Considerations
1) Polymer Gas Permeability:
In addition to Silicone, there are several polymer options for Conformal Coating materials
including Polyurethane, Acrylics, and Polyolefin.
Silicones are known to be more gas permeable than other polymers, and this leads to a
common misperception that silicones are less effective in protecting PCBs. Gas Permeability
is just one of several factors that must be considered. When other properties (adhesion,
stress-relief, temperature resistance) are taken into account, Silicones stand out as an
ideal conformal coating material for protecting PCBs.
Polymer
0.5mm Thickness 1mm Thickness
Silicone (rubber) 215 117
Silicone (resin) 104 55
Polyolefin 6 3
Acrylic 36 30
Polyurethane 32 18
Conformal Coating Failure Mode:
The most common form of PCB failure results from ingress of moisture and contaminants to the
delicate components on the PCB. Moisture accelerates electro-migration between conductors,
leading to failure. It is important to note that corrosion and migration occur when moisture is allowed
to accumulate on the board surface. Although moisture may reach the board, if there is no gap or
void where moisture can accumulate, corrosion can be prevented.

Coating Material Considerations
2) Adhesion:
The presence of cavities where the Conformal Coating has separated
(delaminated) or cracked will create the potential for moisture accumulation
and, eventually, corrosion. It is very important that the Conformal Coating
exhibits good adhesion to the PCB. Regardless of the gas permeability of
the polymer used or thickness at which the Conformal Coating material is
applied, good adhesion is required to help prevent moisture accumulation.
3) Stress-Relief:
Momentive’s Silicone Conformal Coating materials are elastomeric, which
not only provide stress relief to PCB components, but also allow the coating
material to absorb mechanical and thermal stress that occurs when the
PCB undergoes high-to-low temperature cycles, thereby allowing the
conformal coating material to maintain a strong adhesive bond to the
substrate. Rigid Conformal Coatings (polyurethane acrylics, polyolefin and
resin type silicones) can not only apply stress to components, but also
experience delamination or cracking due to their inability to absorb thermal
cycling stress.
4) Heat Resistance:
Silicone Conformal Coating materials typically can be used in operating
conditions ranging from -45 ~ 200C with limited change in properties.
Unlike other polymer types, Silicone Conformal Coating resists hardening
and/or cracking, and is able to maintain properties needed to provide the
required level of adhesion and protection.
Coating material delamination

SALT SPRAY TEST
IEC60068-2-52 SEVERITY 5

Test Standard:
IEC60068-2-52 Severity 5
Test Parameters:
- Salt Spray Cycle: [(Salt Spray at 35 °C x 2 hours)
+ (40 °C, 95% RH x 22 hours)] x 4 cycles (96 hours
total)
- Conditioning Cycle: After each Salt Spray Cycle, dwell
at 23 °C, 50% RH x 72 hours (168 hours total)
- Cycle Repetition: Repeat above process 4 times
(672 hours, 28 days)
Test Samples:
Comb Pattern Boards
Evaluation Criteria:
- Visual confirmation of corrosion
Conformal Coating Salt Spray Test
Note: Test results. Actual results may vary.

G Good. No corrosion C Early stages of corrosion F Fail. Excessive corrosion
Momentive ECC3011
Initial 28 Days
Result
Momentive ECC3051S
Initial 28 Days
Result G
G

Competitor Silicone Resin
Initial 28 Days
Result F
Competitor Polyurethane
Initial 28 Days
Result F

Competitor Polyolefin
Initial 28 Days
Result C
Competitor Acrylic
Initial 28 Days
Result F

Summary
Momentive ECC3011: GOOD
Momentive ECC3051S: GOOD
Competitor Silicone Resin Type: FAIL
Polyurethane: FAIL
Polyolefin: EARLY STAGES OF FAILURE
Acrylic: FAIL
Observations:
- The benefit of anti-corrosion formulation for Momentive ECC series was confirmed
- Highly Solvent Borne competitor grades (silicone & non-silicone) consistently failed.
- The failure of competitor grades was associated with poor PCB surface adhesion.
- Gas permeability of the polymer appeared to be less an issue than thickness & adhesion.

MIXED NOXIOUS GAS CORROSION
(4 GASES)
IEC60068-2-60 METHOD 4

Test Standard:
IEC60068-2-60 Method 4
Test Parameters:
- Place Coated Comb Pattern Boards in Gas Chamber
According to Test Conditions
- Remove after 21 days.
- Visual Inspection to Initial…confirm presence of
corrosion
- Measure Surface Resistance (initial & 21 days)
Test Samples:
Comb Pattern Boards
Mixed Noxious Gas Corrosion Test
Gas Chamber
Coating Materials Tested
• Polyolefin
• Polyurethane
• Acrylic
• Competitor Silicone Resin Type
• Momentive ECC3011
• Momentive ECC3051S
IEC60068-2-60
Method 4
Concentration
(ppm)
H2S
Hydrogen
Sulfide
10 ±5
NO2
Nitrogen
Dioxide
200 ±20
Cl2 Chlorine 10 ±20
SO2 Sulfur Dioxide 200 ±20
Temperature (℃) 25 ±1
Humidity RH% 75 ±3

Momentive ECC3011
Initial 21 Days
Result G
Momentive ECC3051S
Initial 21 Days
Result G

Competitor Silicone Resin
Initial 21 Days
Result C
Competitor Polyurethane
Initial 21 Days
Result C

Competitor Polyolefin
Initial 21 Days
Result C
Competitor Acrylic
Initial 21 Days
Result C

Summary
Momentive ECC3011: GOOD
Momentive ECC3051S: GOOD
Competitor Silicone Resin Type: EARLY STAGES OF FAILURE
Polyurethane: EARLY STAGES OF FAILURE
Polyolefin: EARLY STAGES OF FAILURE
Acrylic: EARLY STAGES OF FAILURE

Grade Salt Spray Mixed Gas Overall
ECC3011 (MPM silicone) ●
ECC3051S (MPM silicone) ●
Competitor Silicone Resin ●
Polyurethane ●
Polyolefin ●
Acrylic ●
Final Assessment
G
G
G
G
G
G
F
F
F
F
F
F
C
C
C
C
C
C

RELIABILITY TESTING
IPC-CC-830B / MIL-I-46058C

IPC Standard Tests:
• Appearance Completed
• Flourescence Completed
• Thickness Completed
• Flexibility Completed
• Dielectric Withstanding Voltage Completed
• Moisture and Insulation Resistance Completed
• Thermal Shock Completed
• Temperature and Humidity Aging Completed

Dielectric Withstanding Voltage
Test Parameters:
- Raise test voltage from zero to 1,500 VAC at
100 VAC per second. Apply the test voltage
of 1,500 VAC at 50-60Hz for one minute and
record any leakage rate
- No evidence of disruptive discharge by
flashover, spark-over, or breakdown.
- The leakage rate shall not exceed 10 micro-
amperes.
Test Samples:
PCB per MIL-I-46058C
Conformal Coating Grade Leakage Rate (μA)
ECC3011 4.6
ECC3051S 4.4
Flexibility
Test Parameters:
- Place a 0.3 cm mandrel in the
center of the coated panel. Bend
one side 180o over the mandrel.
- Inspect for cracking
ECC3011
ECC3051S

Test Parameters:
- Apply a 50 VDC polarizing bias to test patterns.
- Expose test specimens to 20 cycles of temperature and humidity.
- Humidity shall be maintained at 85% minimum
- One cycle is as follows:
- Start test at 25℃ and raise the temperature to 65℃ over a time
span of 1.75 hours.
- Maintain temperature at 65℃ for 3 hours
- Lower the temperature from 65℃ to 25℃ over 1.75 hours
- At Cycle 1, 4, 7 and 10, apply 100 VDC on the specimen’s test points
with the resistance meter without opening the chamber.
- On the 20th cycle, maintain 25℃ relative humidity of 50% for 24 hours
and measure insulation resistance.
- Pass Condition: Insulation resistance shall be > 500 MΩ during humidity
and after 24 hours at reference conditions
Test Samples:
IPC-B-25A coupon
.
Conformal
Coating Grade
Unit Initial 1 Cycle 4 Cycles 7 Cycles
10
Cycles
20 Cycles
(& 24H dwell)
ECC3011 MΩ 2,500,000 117,525 151,299 86,558 121,307 2,125,000
ECC3051S MΩ 2,500,000 55,537 39,319 30,921 42,411 2,500,000

Test Parameters:
- Thermal Shock settings -65 °C ~ 125 °C, dwell time 15 minutes
- Repeat for 100 cycles
- After 100 cycles, maintain at 25°C RH 50% for 24 hours prior to measurement.
- No evidence of disruptive discharge by flashover, spark-over, or breakdown.
- The leakage rate shall not exceed 10 microamperes.
Test Samples:
PCB per MIL-I-46058C
Conformal Coating Grade Leakage Rate (μA)
ECC3011 4
ECC3051S 4
Thermal Shock

Test Parameters:
- Place specimens in a 85°±2°C and 95 ± 4% relative humidity
chamber
- Test up to 120 days and observe specimens at the 28th, 56th, 84th and
120th intervals
- Pass Condition: Evaluate the specimens for evidence of reversion as
indicated by softening, chalking, blistering, cracking, tackiness, loss of
adhesion or liquefaction. Evaluate also legibility of the markings on the
board and/or the resistors.
Test Samples:
IPC “Y” Test Coupon
Temperature and Humidity Aging

Current Packaging: 1 kg Can & Pail

Current Packaging: Bladder Pack
This package consists of a LLDPE Bladder Pack which contains the ECC material, and a pail
can into which the full Bladder is placed. Bladder Packs are placed in pressure tanks to force
out material to spray booth.
Empty Bladder Pack Full Bladder Inside Pails
Adaptor

DISCLAIMER: THE MATERIALS, PRODUCTS AND SERVICES OF MOMENTIVE PERFORMANCE MATERIALS INC. AND ITS SUBSIDIARIES AND AFFILIATES
DOING BUSINESS IN LOCAL JURISDICTIONS (COLLECTIVELY “SUPPLIERS”) ARE SOLD BY THE RESPECTIVE LEGAL ENTITY OF THE SUPPLIER SUBJECT TO
SUPPLIERS’ STANDARD CONDITIONS OF SALE, WHICH ARE INCLUDED IN THE APPLICABLE DISTRIBUTOR OR OTHER SALES AGREEMENT, PRINTED ON
THE BACK OF ORDER ACKNOWLEDGMENTS AND INVOICES, AND AVAILABLE UPON REQUEST. ALTHOUGH ANY INFORMATION, RECOMMENDATIONS, OR
ADVICE CONTAINED HEREIN IS GIVEN IN GOOD FAITH, SUPPLIERS MAKE NO WARRANTY OR GUARANTEE, EXPRESS OR IMPLIED, (I) THAT THE RESULTS
DESCRIBED HEREIN WILL BE OBTAINED UNDER END-USE CONDITIONS, OR (II) AS TO THE EFFECTIVENESS OR SAFETY OF ANY DESIGN INCORPORATING
SUPPLIERS’ PRODUCTS, MATERIALS, SERVICES, RECOMMENDATIONS OR ADVICE. AFOREMENTIONED EXCLUSIONS OR LIMITATION OF LIABILITY ARE
NOT APPLICABLE TO THE EXTENT THAT THE END-USE CONDITIONS AND/OR INCORPORATION CONDITIONS CORRESPOND TO THE RECOMMENDED
CONDITIONS OF USE AND/OR OF INCORPORATION AS DESCRIBED BY SUPPLIER IN ITS PRODUCT DATA SHEET AND/OR PRODUCT SPECIFICATIONS.
EXCEPT AS PROVIDED IN SUPPLIERS’ STANDARD CONDITIONS OF SALE, SUPPLIERS AND THEIR REPRESENTATIVES SHALL IN NO EVENT BE
RESPONSIBLE FOR ANY LOSS RESULTING FROM ANY USE OF ITS MATERIALS, PRODUCTS OR SERVICES DESCRIBED HEREIN. Each user bears full
responsibility for making its own determination as to the suitability of Suppliers’ materials, services, recommendations, or advice for its own particular use. Each user must
identify and perform all tests and analyses necessary to assure that its finished parts incorporating Suppliers’ products, materials, or services will be safe and suitable for
use under end-use conditions. Nothing in this or any other document, nor any oral recommendation or advice, shall be deemed to alter, vary, supersede, or waive any
provision of Suppliers’ Standard Conditions of Sale or this Disclaimer, unless any such modification is specifically agreed to in a writing signed by Suppliers. No statement
contained herein concerning a possible or suggested use of any material, product, service or design is intended, or should be construed, to grant any license under any
patent or other intellectual property right of Suppliers or any of its subsidiaries or affiliates covering such use or design, or as a recommendation for the use of such material,
product, service or design in the infringement of any patent or other intellectual property right.
Momentive and the Momentive logo are trademarks of Momentive Performance Materials Inc.
More information available at
www.momentive.com/conformalcoatings/

Momentive Silicone Conformal Coating Overview

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