A methodology is presented that allows the evaluation of the thermomechanical reliability of electronic packages using “virtual prototyping.” Here, a virtual flip chip ball grid array (FC-BGA) is examined in comparison to a reference chip scale package (CSP). The comparison is performed using finite element simulation. A combined measurement-simulation technique is used to calibrate the finite element simulations on a reference object. The adjustment is based on the in-plane deformation field obtained by both simulation and optical measurement. For the latter, an optical sensor is used for in-plane deformation and strain field analysis based on the gray-scale correlation method. The findings obtained can be extrapolated to alternative package types with different but similar design to evaluate their suitability for the desired application before physical fabrication.

The thermomechanical reliability of the package and interconnections of assembled flip chip ball grid arrays (FC-BGA) is investigated in comparison to a reference chip scale package (CSP). Comparison is made using finite element (FE-) simulation. A combined measuring-simulation technique is applied to calibrate the finite element simulations on a reference object. Adjustment is made based on the in-plane deformation field evaluated by both simulation and optical measurement. For the latter an optical sensor for in-plane deformation and strain field analysis is used based on grey scale correlation method. A methodology is presented and to extrapolate the knowledge gained to alternative package types of different but similar design in order to evaluate their suitability for the desired application before the physical fabrication (virtual prototyping).

More and more dense packaging is one of the most important challenges in advanced electronics and micro technology, driven by requirements like low cost and high reliability. One way to meet these demands is to follow the so-called ldquochip in duromerrdquo approach, which allows an extremely dense integration and very short interconnects. Already in the very first design phase of advanced products, numerical studies by means of finite element analyses (FEA) are very efficient to check the desired properties regarding functionality as well as reliability aspects. This has been carried out with a new generation of active distance control (ADC) devices for automobiles, based on a radar principle. In order to obtain sufficiently flat modules for subsequent manufacturing steps, thermally induced deformations were measured at suitable specimens by means of the microDAC technique, developed by CWM GmbH Chemnitz and Fraunhofer IZM. Combining FE analyses and measured deformations, a methodology was developed which can be generalised and applied to many design procedures before any real parts are available [1]. It is helpful to reduce cost and time-to-market for future products by minimising real tests and an expensive redesign.