The main aim of this study is to extending the holographic interferometry technique to measure the out-of-plane displacement of an object subjected to both temperature and displacement field. It is noted that both the out-of-plane displacement and the ambient temperature change can cause image fringes. Therefore, an auxiliary object is used to identify the fringe numbers caused by the ambient temperature change during the experiment. The warpage measurement of a PBGA package is used as an example. It can be shown that the proposed method works

Currently the trend of electronic product development is to ward ¡§light and thin, multi-functional, high density and durability¡¨. When the microelectronic chips tend to be high power, high density and high speed, the rapid increase of heat in a reduced unit area of package size, will lead to failure of electronic products. The contents of thesis is to find out the dominant factors in heat transfer by changing the geometries and material properties of QFN and BGA packages. It also aims to achieve the beat the thermal performance by reducing the probability of failure. In industries it needs a lot of cost and time in experiment work due to the changes of size and materials. Herein, the softwares of ANSYS and ICEPAK are adopted to model the QFN and BGA packages with the statistical experimental design of Taguchi method L18 (21¡Ñ37) orthogonal array setting parameters and obtain the degree of effect for each factor. Eventually, we use the analysis of variance ANOVA to obtain the contribution of each factor and to identify the significant degree for various parameters by variance error integration. From the results the die attach thermal conductivity affects the contribution of thermal performance up to 81.46% for QFN package in comparison with other controlling factors of high significance and high impact effects. Die attach thermal conductivity between 0.5 W/m•k and 1.5 W/m•k the Tj declines much larger than that between 1.5 W/m•k and 8 W/m•k. Die /PKG area ratio affects the contribution of the thermal performance to 64.24% and increasing Die /PKG area ratio can reduce the Tj for BGA package. The significant effect is also higher than other factors. However, the contribution of substrate layers is 18.83% at 99% confidence level.

The subject of this dissertation is the development of three-dimensional (3D) surface profilers for semiconductor back-end inspection. The value of this study is: 1) to provide a new phase-to-height relationship for Fourier Transform Profilometry (FTP) that is universal as it allows alternate FTP system architectures for a micrometer scale object measurement, and 2) to provide a new method for full field substrate warpage and ball grid array (BGA) coplanarity inspection using machine vision. The desire to increase electronic device performance has resulted in denser and smaller IC packaging. As the dimensions of the devices decrease, the requirements for substrate flatness and surface quality become critical in avoiding device failure. For a high yield production, there is an increasing demand in the requirement for the dimensional verification of height, which requires 3D inspection. Based on the current demands from the semiconductor industry, this dissertation addresses the development of fast in-line surface profilers for large volume IC package inspection. Specifically, this dissertation studies two noncontact surface profilers. The first profiler is based on FTP for measuring the IC package front surface, the silicon die and the epoxy underfill profile. The second profiler is based on stereovision and it is intended for inspecting the BGA coplanarity and the substrate warpage. A geometrical shape based matching algorithm is also developed for finding point correspondences between IC package images. The FTP profiler provides a 1 σRMS error of about 4 μm for an IC package sample in an area of 14 mm x 6.5 mm with a 0.13 second data acquisition time. For evaluating the performance of the stereovision system, the linearity between our system and a confocal microscope is studied by measuring a particular IC sample with an area of 38 mm x 28.5 mm. The correlation coefficient is 0.965 and the 2σdifference in the two methods is 26.9 μm for the warpage measurement. For BGA coplanarity inspection the correlation coefficient is 0.952 and the 2difference is 31.2 μm. Data acquisition takes about 0.2 seconds for full field measurements.