Dynamic Mechanical Relaxation Testing for High Temperature Die Attach Polyimides
Dynamic mechanical relaxation testing isolates glass transition, creep compliance, and thermal stability in high temperature die attach polyimides.
Dual Cantilever
Mechanical Arrangement
A pair of opposing elastic members anchored to a common base allows for the simultaneous measurement of strain or deflection on both faces of a probe. This dual cantilever assembly isolates the sensing component from unwanted thermal gradients or axial loads by balancing the force distribution across two mirrored supports. Bending moments applied to one side generate a proportional output signal through a strain gauge circuit while the second element functions as a reference to reject common mode interference.
Differential readings obtained through this configuration minimize errors that arise from ambient vibrations or temperature fluctuations.
Sensor Calibration
Standards defined by the International Organization for Standardization require that the sensitivity of both arms stays within a defined variance during static load testing. Technicians apply a known mass to the distal end of each beam to record the output voltage against the theoretical displacement curve. Deviations beyond the accepted tolerance indicate a misalignment in the mounting interface or a fatigue-induced change in the material modulus of the flexure.
Periodic verification ensures the symmetry of the response remains constant over the operational life of the device.
Performance Characteristic
Dynamic response times depend on the mass of the beam tip and the stiffness of the structural material chosen for the assembly. High resonant frequencies allow for precise capture of rapid force transients without ringing or signal overshoot. The gap between the two beams limits the maximum travel distance to prevent mechanical contact that would otherwise damage the sensing elements or shift the zero point.
Maintaining a strict separation distance remains necessary to ensure the linearity of the measurement across the full range of motion.
Installation Requirement
Mounting surfaces must exhibit high rigidity to prevent the base of the unit from contributing parasitic deformation to the measurement result. Alignment of the primary axis with the direction of the load reduces crosstalk from lateral forces that could introduce errors in the bridge excitation signal. Fasteners require a consistent torque to ensure the contact area does not shift under repeated stress cycling.
Secure coupling between the unit and the frame provides the fixed boundary condition essential for accurate analytical performance.