Substrate Design Augmentation for Die Placement Reference at Die Attach Process

Die placement reference in die attach process is one of the critical aspects in measuring the actual die placement especially for the device that has a required measurement. This paper focused on the re-design on the layout of the substrate ball grid array (BGA) package with cross fiducials at the singulation lane which are located at the corner portions of the device. The cross fiducial would serve as a reference when measuring the actual placement of the Silicon die in the package. With this improvement, the technicians and operators could now easily identify the reference based on the mount and bonding diagram requirement.

Optimization of a compact thermal model for a Ball Grid Array (BGA) package using experimental data

The goal of this research is to optimize a static and dynamic compact thermal model for a ball grid array (BGA) package using experimental data. The general objectives of thermal modeling are to increase the accuracy of electrical analysis to enhance the performance of the electronic systems. The project is focused on generating the static and dynamic compact thermal model of a Bipolar Junction Transistor (BJT) and a Ball Grid Array (BGA) based on experimental results of infrared (IR) camera system , so that the steady state and transient thermal behaviors of the package could be predicted fast with required accuracy. The approach proposed by a previous study based on generation of dynamic compact thermal model of a BGA package using simulation tools, is extended in this work to generate the static and dynamic compact model of the same package represented by a RC (thermal) network or admittance matrix based upon a methodology which couples different layers of experimental data to the error minimization notion of the problem. This optimization problem sets the temperature profile experimental data as a standard and compares the compact model's computed temperature and refines itself with a feedback, until reaching a desired point.

Optimization of a compact thermal model for a Ball Grid Array (BGA) package using experimental data

The goal of this research is to optimize a static and dynamic compact thermal model for a ball grid array (BGA) package using experimental data. The general objectives of thermal modeling are to increase the accuracy of electrical analysis to enhance the performance of the electronic systems. The project is focused on generating the static and dynamic compact thermal model of a Bipolar Junction Transistor (BJT) and a Ball Grid Array (BGA) based on experimental results of infrared (IR) camera system , so that the steady state and transient thermal behaviors of the package could be predicted fast with required accuracy. The approach proposed by a previous study based on generation of dynamic compact thermal model of a BGA package using simulation tools, is extended in this work to generate the static and dynamic compact model of the same package represented by a RC (thermal) network or admittance matrix based upon a methodology which couples different layers of experimental data to the error minimization notion of the problem. This optimization problem sets the temperature profile experimental data as a standard and compares the compact model's computed temperature and refines itself with a feedback, until reaching a desired point.

Generation and evaluation of dynamic compact thermal model of electronic packages

The goal of this research is to develop a Dynamic Compact Thermal Model (DCTM) of electronic packages. The general objectives of thermal modeling are to increase the accuracy of electrical analysis by taking the effect of temperature variation into consideration, predicting the reliability of the product, and acquiring the information which is necessary to design the cooling system in order to enhance the performance of the electronic systems. The project is focused on generating the dynamic compact thermal model of electronic packages so that the transient thermal behaviors of the package could be predicted fast and accurately. The approach proposed by DELPHI consortium (a collaborative European project) for static compact thermal model generation is extended in this work to generate the dynamic compact model of a BGA package represented by a RC network or admittance matrix. Two steps performed as the methodology of dynamic compact model generation in this work are: 1- A static compact thermal model of BGA package is generated and validated from the static thermal simulation and 2- A RC network is proposed as the contribution of this work and calculated by optimization as the dynamic compact thermal model of the package using the data of transient simualtion. The size of the proposed RC network then is optimized by eliminating some capacitors from the original RC network and validated by comparing its output to the ouptut of finite element simulation. COMSOL©, a Finite element analysis tool is used for thermal simulation and detailed steady state and transient model generation. The optimization algorithm implemented for both static and dynamic compact model generation is Nelder-Mead multidimensional optimization which is realized by MATLAB© programming. The obtained results from the compact models for both static and dynamic analysis of the BGA package are in agreement with the detailed thermal model results and with the available results in literature.

Generation and evaluation of dynamic compact thermal model of electronic packages

The goal of this research is to develop a Dynamic Compact Thermal Model (DCTM) of electronic packages. The general objectives of thermal modeling are to increase the accuracy of electrical analysis by taking the effect of temperature variation into consideration, predicting the reliability of the product, and acquiring the information which is necessary to design the cooling system in order to enhance the performance of the electronic systems. The project is focused on generating the dynamic compact thermal model of electronic packages so that the transient thermal behaviors of the package could be predicted fast and accurately. The approach proposed by DELPHI consortium (a collaborative European project) for static compact thermal model generation is extended in this work to generate the dynamic compact model of a BGA package represented by a RC network or admittance matrix. Two steps performed as the methodology of dynamic compact model generation in this work are: 1- A static compact thermal model of BGA package is generated and validated from the static thermal simulation and 2- A RC network is proposed as the contribution of this work and calculated by optimization as the dynamic compact thermal model of the package using the data of transient simualtion. The size of the proposed RC network then is optimized by eliminating some capacitors from the original RC network and validated by comparing its output to the ouptut of finite element simulation. COMSOL©, a Finite element analysis tool is used for thermal simulation and detailed steady state and transient model generation. The optimization algorithm implemented for both static and dynamic compact model generation is Nelder-Mead multidimensional optimization which is realized by MATLAB© programming. The obtained results from the compact models for both static and dynamic analysis of the BGA package are in agreement with the detailed thermal model results and with the available results in literature.

Stochastic Finite Element Thermal Analysis of a Ball Grid Array Package

This paper presents a straight-forward finite element approach for the quantification of electronic package thermal performance under uncertainty. The method makes use of high accuracy sensitivity calculations and a gradient-based minimization method. The approach was applied to the thermal analysis of a Ball Grid Array (BGA) package under uncertainty to illustrate its capabilities. The effect of uncertainty in the heat source, heat transfer coefficient, ambient temperature and thermal conductivities of the component materials on the probability of exceeding a specified average junction temperature at the die-heat-spreader interface was studied. In addition, the performance and accuracy of two different methods for computing the required sensitivities were compared. Results showed that the average junction temperature probability was more sensitive to some system parameters over others, providing crucial information for selecting the manufacturing tolerance of BGA package components. For parameters identified as especially sensitive, selecting components with tighter tolerances will reduce uncertainty and increase the overall reliability. And for less sensitive parameters, selecting larger tolerance could help reduce manufacturing cost.