Optical Meso-Measurement Techniques And Its Applications To Experimental Investigation Of Microelectronic Module

First of all,this research targets the international forward problems with regard to interface mechanics of compound microelectronic module, reviews basic theory of fracture mechanics ,summarizes theoretical and experimental study on failure properties of compound microelectronic packing module, points out its urgency and necessary for overall experimental studys of the failure properties in the microelectronic packing module, and proposes its new requirements of experimental technique.Then,this research summarizes the development of experimental techniques, analyses and proves its merits and demerits. Furthermore some new measurement techniques are proposed and developed, and failure properties of microelectronic packing module are studied for the first time by these techniques.In this research,the thickness, stress-strain curves and some mechanical properties of the thin film in compound microelectronic module are studied by modern experimental methods of white light speckle, digital speckle with use of the spec-troscopy, the surface measurement system and image-processing system. Meanwhile the separative method of composite materials is used successfully. The stress-strain curves and some mechanical properties of thin film and ultra-thin film are ob-tained.The results show that the experimental techniques and the separative method of composite materials in this research are potential to be measure the stress-strain curves and some mechanical properties of the thin film and ultra-thin film in microelectronic packing module.On the basic of moire interferometry, a marvelow combination of moire in-terferometry ,micro technique, multiplication technique ,carrier technique, reversal technique and non-linear recording technique is proposed for enlarging and multi-pling moire interference fringes, where the U,V displacement fields are involved at the same time. By using this method, enlarging rate of the common optical system can be increased by ten times and the displaceinent measuring sensitivity of moire interferometry can be incerased over an order of magnitude. On the other hand, a high temperature micro-multiply moire interferometry system is developed by combining this method with high-temperature measuring technique. This method is applied to experimental study for the displacement fields around interlayer crack tip of compound microelectronic module under different thermal loadings. The results show that the displacement fields around crack-tip of module have exponential singularity under thermal loadings.For the first time, virtual gratings is drawn into the projection moire method, and combined with holographic interferometry, then a large measuring range new technique for measuring the whole deformative and damage process of compound microelectron module-holography quasi projection moire method—is proposed. By this method, the experimental study was done for studying the failure modes (deco-hesion, delamination, spalling, buckling, curving and crushing etc) of microelectronic packing module under thermal loadings. The experimental results show: when the mechanical strength of film/substrate bonded systems is weak, the interface will produce decohesion, delamination and spall;If strength of the film is far lesser than the substrate, the film will curve suddenly after delamination;If the film is ductile and the substrate is brittle, the film will buckle from the substrate;otherwise, the film will crush from the substrate.Finally, residual stress and its distribution in microelectronic packing module are measured by moire interferometry. Meanwhile, the singularity around interface crack-tip, influence of metal plasticity, interface fracture resistance and crack growing direction etc in the interface of sandwich specimen were studied by reflection holography-moire interferometry. The results show: the solution of the Dundurs'elastic mismatch parameters for bimaterials based on linear-elastic fracture mechanics is suit for small scale yielding in multi-layer electronic packages. First the crack propagation is short along the initial interfacial crack, then the crack grows along 45° direction of the bonded systems and splits out the film ductile layer, finally the crack grows steady-state along the weak bonded interface.