Conformal Coating and NI RIO Products

Publish Date: Sep 30, 2019 | 4 Ratings | 4.75 out of 5 | Print


This paper provides a brief introduction to Conformal Coating benefits and use cases. It also discusses the ELPEGUARD SL 1307 FLZ coating created by Lackwerke Peters that is available on some National Instruments RIO products.

Conformal Coating

Conformal coatings are specially formulated thin film materials that are applied directly to circuit boards or circuit card assemblies (CCAs).  These films provide environmental protection for components and circuitry.  The thin film materials used for conformal coating are normally applied using a process of dipping or spraying the CCA with a liquid or resinous material.  As the material dries, it forms a resilient coating that can protect against moisture, mold, dust, corrosion and other environmental stresses.


Condensation can occur when the outside air temperature increases at a faster rate than the electronics.  If the temperature of the electronics reaches the dew point, condensation will occur.  The higher the relative humidity, the closer the dew point is to the current temperature.  This scenario could occur if a product was stored in a vehicle over night.  When the outside air heats up, there is a potential for the electronics to reach their dew point.  This occurs on the aluminum enclosures due to the thermal capacitance of aluminum.  Once condensation forms on the enclosure, there is a higher probability of shorts on the CCA.

The application of a conformal coating prevents condensation from making contact with traces, vias, and integrated circuits (IC’s) on CCAs.  This prevents the formation of corrosion and shorting on these components after exposure to condensation.  Connectors do not benefit from the conformal coating, so corrosion could still occur at the connectors.  The conformal coating is intended to extend the life of the product by protecting the traces, vias, and fine pitch IC’s, but it does not eliminate all environmental risk associated with the connectors.

Figure 1. Conformal coated CCA shows no corrosion after exposure to condensation

Figure 2. Corrosion has occurred on the uncoated CCA after exposure to condensation

To minimize corrosion on connectors, National Instruments recommends the following tips:

•         Mount the system in horizontal orientation, with the I/O connectors facing forward.  This allows condensation to run off the CCA’s and not to pool up in the connectors.

•         Do not create any drip lines with cabling.  All cables should be routed down, so any condensation that occurs on the cable will not be channeled into the connector or product.

•         Ensure the electronics are not in other drip lines

•         To help protect backplane connectors, use a filler module or dust cover in any empty slot.

National Instruments uses ELPEGUARD SL 1307 FLZ to provide environmental protection for certain products.  This modified acrylic resin is manufactured by Lackwerke Peters (see manufacturers datasheet for technical specifications). 

ELPEGUARD SL 1307 FLZ has been approved as a conformal coating by UL under QMJU2.E80315.  Additionally, National Instruments has tested the conformal coated products for the following environmental specification.



Operating humidity

(IEC 60068-2-30 Test Db)……………….80 to 100% RH, condensing

Additional test reports and datasheets on the coating material, ELPEGUARD SL 1307 FLZ, are available in the Developer Zone.  These tests were not performed on National Instruments products, they are provided to reference the properties of the conformal coating.


Products Available with Conformal Coating

The table below shows the C Series modules and CompactRIO and Single-Board RIO systems available with conformal coating.  If the particular system or I/O module you need for you application is not available please contact National Instruments.

Figure 3. CompactRIO Packaged and Single-Board RIO Board-Level Systems

Model Number Description
CompactRIO Controllers and Chassis
cRIO-9038 8-slot, Intel Atom & Kintex-7 160T Integrated Real-Time Controller and Chassis
cRIO-9068 8-Slot, Zynq-7020 Integrated Real-Time Controller and Chassis
cRIO-9065 4-Slot, Zynq-7020 Integrated Real-Time Controller and Chassis
cRIO-9014 CC Real-Time Controller with 400 MHz processor, 2 GB Storage
cRIO-9023 CC Real-Time Controller with 533 MHz processor, 2 GB Storage
cRIO-9025 CC Real-Time Controller with 800 MHz processor, 4 GB Storage
cRIO 9113 CC 4-Slot, Virtex-5 LX50 CompactRIO Reconfigurable Chassis
cRIO-9114 CC 8-Slot, Virtex-5 LX85 CompactRIO Reconfigurable Chassis
cRIO-9118 8-Slot, Virtex-5 LX110 CompactRIO Reconfigurable Chassis
Single-Board RIO Devices
Contact your NI Account Manager to discuss Conformal Coating on Single-Board RIO
C Series Analog Input Modules
NI 9203 CC 8-Channel +/-20mA, 16-bit Current Input Module, Screw
NI 9205 CC 32-Channel +/-10V, 16-Bit, 250 kS/s Voltage Input Module, DSUB
NI 9207 CC 16-Channel (8 Voltage and 8 Current), +/-10V and +/-21.5mA, 500 S/s, 24-bit Analog Input Module, DSUB
NI 9208 CC 16-Channel +/-21.5mA, 500 S/s, 24-bit Current Input Module, DSUB
NI 9213 CC 16-Channel Thermocouple Module, Screw
NI 9219 CC 4-Channel, TC, RTD, Resistance, Bridge, Voltage, Current, 100 S/s/ch, 24-bit Universal Input Module, Spring
NI 9221 CC 8-Channel, +/-60V, 800 kS/s, 12-bit Voltage Input Module, DSUB
NI 9225CC 3-Channel, 300 Vrms Voltage Input Module,Screw
NI 9227 CC 4-Channel, 5 Arms, 50 kS/s/ch, 24-bit Current Input Module, Screw
NI 9230 CC 3-Channel, +/-30V, 12.8 kS/s/ch, IEPE. Voltage Input Module, Screw
NI 9232 CC 3-Channel, +/-30V, 102.4 kS/s/ch, IEPE, Voltage Input Module, Screw
NI 9234 CC 4-Channel, +/-5V, 51.2 kS/s/ch, 24-bit, IEPE, Voltage Input Module, BNC
NI 9237 CC 4-Channel, Bridge-based, 50 kS/s/ch, 24-bit, Voltage Input Module, DSUB
NI 9239 CC 4-Channel, +/-10V, 50 kS/s/ch, 24-bit, Ch-Ch Iso, Voltage Input Module, Screw
C Series Analog Output Modules
NI 9264 CC 16-Channel +/- 10V, 25 kS/s/ch, 16-Bit, Voltage Output Module, DSUB
NI 9265 CC 4-Channel, 100 kS/s, 16-Bit, 0 to 20 mA Current Output Module, Screw
NI 9269 CC 4-Channel, +/- 10V, 100 kS/s/ch, 16-bit, Ch-Ch Iso, Voltage Output Module, Screw
C Series Digital Input Modules
NI 9401 CC 8-Channel, 5V/TTL, 100 ns, Sinking/Sourcing, Bidirectional Digital I/O Module, DSUB
NI 9403 CC 32-Channel, 5V/TTL 7 us, Sinking/Sourcing, Bidirectional Digital I/O Module, DSUB
NI 9411 CC 6-Channel, 500 ns, +/- 5 to 24V Digital Input Module
NI 9421 CC 8-Channel, 24 V, 100 us, Sinking, Digital Input Module, DSUB
NI 9425 CC 32-Channel, 24 V, 7 us, Sinking Digital Input Module, DSUB
NI 9426 CC 32-Channel, 24 V, 7 us, Sourcing Digital Input Module, DSUB
NI 9437 CC 8-Channel, 24 V to 250VDC, 1 us, Sinking Digital Input Module, Screw
C Series Digital Output Modules
NI 9475 CC 8-Channel, 60 V, 1 us, Sourcing Digital Output Module, DSUB
NI 9476 CC 32-Channel, 24 V, 500 us, Sourcing Digital Output Module, DSUB
NI 9477 CC 32-Channel 5 to 60 V, 8 us, Sinking Digital Output Module, DSUB
NI 9478 CC 16-Channel, 48 V, 50 us, Sinking Digital Output Module, DSUB
NI 9485 CC 8-Channel, 60VDC/30Vrms, 750 mA, SSR Relay Output Module, Screw
C Series Communications Modules
NI 9853 CC 2 Port, High-Speed Controller Area Network (CAN) Module
NI 9870 CC 4-port, RS232 Serial Interface Module, RJ50
NI 9871 CC 4-Port, RS485/RS422 Serial Interface Module, RJ50
C Series Communications Modules
NI 9802 CC Secure Digital Storage Module
C Series Timing & Synchronization Modules
NI 9469 CC Signal Based Synchronization Module, RJ45





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