How to Select Adhesives for Bonding & Fixing Inductors
Required Performance of Inductors Bonding Fixing Adhesives Inductors, coils, magnetic cores and power electronic components are subject to long-term temperature rise, mechanical vibration, thermal cycling and electrical stress during operation. Inductor Potting Compound Insufficient bonding strength of fixing adhesives, or cracking & debonding after curing, may lead to loose inductors, abnormal noise, pin fatigue or even abnormal electrical performance. Therefore, adhesives for bonding and fixing inductors must meet all the following requirements: ■ Excellent adhesion to magnetic cores, metals, PCBs and plastic bobbins; ■ Good anti-sagging property after dispensing to retain the shape of adhesive dots and lines; ■ High structural strength after full curing; ■ Outstanding electrical insulation performance; ■ Resistance to high-low temperature cycling and long-term operating temperatures; ■ Compatible with manual dispensing and automatic dispensing processes. For different inductor fixing structures, ELAPLUS, a manufacturer of electronic adhesives, offers four epoxy structural bonding fixing adhesives: EP 2011, EP 1769, EP 1767 and EP 1763. EP 2011: Suitable for Medium-Temperature Curing & Ambient Storage Processes EP 2011 is a two-component epoxy structural adhesive in grey paste with slight thixotropy. Inductor Fixing Adhesive It can be stored under ambient temperature away from light. The recommended curing profile is heating at 80°C for 1 hour. It is ideal for inductor fixing applications that require high structural strength without high curing temperatures. Typical properties: ■ Thixotropic index: 3.5 ■ Hardness after curing: Shore D 83 ■ Glass transition temperature (Tg): 55°C ■ Shear strength: 16 MPa ■ Volume resistivity: 1.2×10¹⁵ Ω·cm ■ Dielectric constant: 3.3 ■ Operating temperature range: -40 ~ 120°C EP 2011 is applicable to magnetic core fixation of inductors, coil assembly bonding, electronic component reinforcement and general structural bonding for industrial electronics. EP 1769: High Tg & High-Strength Solution for Inductor Fixing EP 1769 is a single-component grey paste epoxy adhesive with typical viscosity of 300,000 cps at 25°C and thixotropic index…
