Polymeric systems for potting and encapsulation of hi-tech electronic parts
- The offered product is a cost effective two-component polymeric system for potting and encapsulation of electronic parts. - The developed system is unique for combination of electrical resistance, high thermal conductivity and dimensional stability during thermal cycling at maintaining mechanical properties and adhesion to metallic substrates. - TOSEDA is seeking potential commercial customers/end users of this product.
- The offered product is a two-component polymeric system modified by tailor designed nanostructures - Applicable by casting - Viscosity ≤ 10 Pa.s - Working time at RT: 1-3 h - Curing time at RT ≤ 24 h - Volume resistivity ≥ 1 GΩ.m - Temperature range min from - 25 °C to 75 °C - Tensile strength at RT ≥ 7 MPa - Tensile strength at 75 °C ≥ 5 MPa - Elongation at break ≥ 8 % (RT) - Elongation at break ≥ 3 % (-25 °C) - Pull off strength before thermal cycling ≥ 3 MPa (Aluminum substrates) - Pull off strength after thermal cycling ≥ 2.65 MPa (Aluminum substrates) - High temperature humidity absorption ≤ 3% - Linear thermal expansion coefficient < 2 10 -4 K-1 - Thermal conductivity ≥ 0.35 W/(K.m)
Innovations & Advantages
The new encapsulating material will provide compared to the standard commercial products the following advantages: - Higher adhesion to metallic substrate (to eliminate loss of adhesion to metallic substrate during thermal cycling) - Lower thermal expansion coefficient (to eliminate internal stress generation and loss of adhesion to metallic substrate during thermal cycling) - Higher thermal conductivity (to dissipate heat generated by the electrical parts to avoid the electronic devices overheating and their failure during operation)
The polymeric elastomeric material developed previously by TOSEDA originally for special space applications was identified as highly efficient material suitable for encapsulation of different electronic parts such as high precision pressure sensors, supercapacitors, PCB boards etc. The requirement for such applications is to provide excellent adhesion of the casting material to metallic surfaces in a very broad temperature range without dramatic changes of thermal expansion coefficient. This condition is well met by TOSEDA´s space heritage. The material must be also electrically non-conductive to avoid short-cuts of the electrical units during its operation. Standard commercial encapsulation polymeric systems do not fulfill the criteria, particularly the adhesion and dimensions stability during temperature changes. These problems can be effectively solved by application of nano-filled casting system developed by TOSEDA for extreme space conditions that include thermal cycling without loss of adhesion to metallic surfaces and loss of mechanical properties. This performance can’t be observed using conventional polymeric encapsulation systems. The TOSEDA’s material can find very broad applicability as casting resin targeted for example for aerospace industry, where the electronic devices are exposed to fast temperatures changes from the ground atmosphere temperature (up to ca 70 °C) to flight negative temperature (ca -50 °C) without affecting the efficiency of the electrical devices.
Current and Potential Domains of Application
The most perspective non-space applications of TOSEDA’s developed system are electronic and aerospace industries. The TOSEDA’s material is suitable to be used as potting and encapsulating material superseding conventional casting resins.