Tflex™ HR400

Tflex™ HR400

Silicone based Thermal Gap Filler


Tflex HR400 is a cost-effective and compliant gap filler thermal interface material with excellent thermal performance and great handling for mass-production applications.

The low modulus interface pad conforms to component topography resulting in little stress on the components mating chassis or parts. The softness relieves mechanical stress from high stack-up tolerance and absorbs shock resulting in improved device reliability.

Tflex HR400’s recovery properties for applications requiring material rework result in continued mechanical integrity even after device rework and re-assembly. Tflex HR400 is naturally tacky on both sides and requires no additional adhesive coating to inhibit thermal performance. The tack is designed to hold the pad in place during assembly and component transport.

Tflex HR400 is electrically insulating stable from -50?C thru 160?C and meets UL 94V0 flame rating.

STANDARD THICKNESSES Standard thickness is 0.020-inch (0.5 mm) through 0.400-inch (10.2 mm) and available in 0.010-inch increments. Please contact Laird Technologies for availability of thicknesses above 0.200-inch. OPTIONS Fiberglass is standard in 0.020-inch and 0.030-inch thicknesses to aid in handling and is designated by the suffix œ-FG. Material is standard with both sides tacky; the -DC1 suffix indicates only one side is tacky. MATERIAL NAME AND THICKNESS Tflex indicates Laird Technologies™ elastomeric thermal gap filler product line. HR4XXX indicates Tflex HR400 product line with thickness in mils (0.001-inches); -DC1 indicates only one side tacky; -FG indicates fiberglass reinforcement. Data for design engineer guidance only. Observed performance varies in application. Engineers are reminded to test the material in application.

Features and Benefits

  • Soft and Compliant
  • Available in thicknesses from 0.020” thru 0.400” (0.5mm thru 10.2mm)
  • Naturally tacky for adhesion during assembly and transport
  • Environmentally friendly solution that meets regulatory requirements including RoHS and REACH


Automated PackagingAutomated Pad PlacementCustom AutomationCustom Product DevelopmentModelingPrototypingServiceTesting

Technical Specification

Typical PropertiesColorDark Grey
Density (g/cc)1.90
Operating Temperature Max (Celsius)160
Operating Temperature Min (Celsius)-40
Outgassing CVCM (%)0.090
Outgassing TML (%)0.320
Shelf Life2 years from Date of Shipment
Thermal PropertiesThermal Conductivity (W/mK)1.80
Thermal Resistance @10 psi Max (C-in2/W)4.080
Thermal Resistance @10 psi Min (C-in2/W)0.492
Electrical PropertiesDielectric Constant4.80
Volume Resistivity2.00 x10^13 Ohm-cm
Mechanical PropertiesHardness (Shore 00)53
DimensionsThickness Max (inches)0.350
Thickness Max (mm)7.62
Thickness Min (inches)0.020
Thickness Min (mm)0.50
ROHS CompliantYes
UL Flammability RatingV-0


Last Updated: 27/12/21
Last Updated: 27/12/21
Last Updated: 27/12/21
Last Updated: 22/04/21




Automotive ADASAutomotive ElectronicsAutomotive InfotainmentAutomotive Powertrain/ECUsDrones/SatellitesGaming SystemsInstrumentationNotebooks/Tablets/Portable DevicesRoutersSmart Home DevicesWireless infrastructure