Advanced viscoelastic material model for predicting warpage of a QFN panel

Vreugd, J. de; Jansen, K.M.B.; Xiao, A.; Ernst, L.J.; Böhm, Christoph; Kessler, A.; Preu, H.; Stecher, M.

doi:10.1109/ectc.2008.4550196

Cited by 20 publications

(2 citation statements)

References 6 publications

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“…More detailed content can be found in [1] The mechanical properties of molding compound are highly dependent on temperature and time in the temperature range at which the molding compound is cooled down from molding temperature to room temperature. DMA tests are done to obtain the time and temperature dependent Young's modulus.…”

Section: Study Of Materials Model Of Emcmentioning

confidence: 99%

Establishing fracture properties of EMC-Copper interfaces in the visco-elastic temperature region

Xiao

Vreugd

Pape

et al. 2009

2009 59th Electronic Components and Technology Conference

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An ongoing root cause of failure in microelectronic industry is interface delamination. In order to explore the risk of interface damage, FE simulations for the fabrication steps as well as for the testing conditions are generally made in the design stage. In order to be able to judge the risk for interface fracture, the critical fracture properties of the interfaces being applied should be available, for the occurring combinations of temperature and moisture preconditioning. As a consequence there is an urgent need to establish these critical interface fracture parameters. For brittle interfaces such as between epoxy molding compound (EMC) and metal (-oxide) substrates the critical energy release rate (or delamination toughness) can be considered as the suitable material parameter. This material parameter is strongly dependent on the temperature, the moisture content of the materials involved and on the so-called mode-mixity of the stress state near the crack tip. The present study deals with experimental investigation of the delamination toughness of EMC-Copper lead-frame interfaces as can directly be obtained from the production line. The experimental set-up as designed for this purpose was previously reported, together with some measurement results and toughness evaluations for room temperature fracture tests. This study deals with experiment and simulation procedure of establishing the interfacial fracture toughness from fracture test results at high temperatures, especially in the glass transition temperature region of epoxy molding compound (EMC). In order to calculation accurate fracture toughness, the material property of molding compound is characterized as a function of temperature. A detailed discussion of how EMC responses at its glass transition region will be provided. The influence of the material property on interfacial fracture toughness will be given.

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Section: Study Of Materials Model Of Emcmentioning

confidence: 99%

Establishing fracture properties of EMC-Copper interfaces in the visco-elastic temperature region

Xiao

Vreugd

Pape

et al. 2009

2009 59th Electronic Components and Technology Conference

Self Cite

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“…de Vreugd [4] described the viscoelastic properties of molding compound in detail using DMA and pointed out the CTE of the molding compound varying over temperature.…”

Section: Introductionmentioning

confidence: 99%

Characterization, modelling, and parameter sensitivity study on electronic packaging polymers

Niu

Yang

Zhang

2009

2009 International Conference on Electronic Packaging Technology &Amp; High Density Packaging

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Thermosetting polymers are widely used in electronic packaging. For instance, epoxy molding compound is extensively used as an encapsulant for electronic packages to protect the IC chips from mechanical and chemical hazards. It is well known that molding compounds show not only strong temperature dependent but also time dependent behavior. The thermo-mechanical behavior of these polymer constituents determines the performance, such as functionality and reliability, of the final products. In this paper, experimental characterization was carried out to investigate the time and temperature dependent properties of the selected molding compound. Thermal Mechanical Analysis (TMA) was applied to measure the CTE of the materials. Dynamical Mechanical Analysis (DMA) measurement was performed using temperature and frequency sweep modes. Finite element modeling was conducted on typical QFN (Quad Flat Nonlead) package device. Three material models, i.e., full viscoelastic model, temperature-dependent elastic model (1Hz DMA data) and constant elastic model, are used respectively to describe the behavior of the molding compound. The output responses of the simulations are von Mises stress distribution, package warpage and interlaminar stresses. The results show that the von Mises stress and package warpage are significantly different when considering the EMC as full viscoealstic, temperature-dependent elastic and constant elastic. IntroductionAccording to the developing trends of microelectronics, the development and application of polymers becomes one of the bottlenecks for the microelectronic industry. With the introduction of new packaging materials there are many new requirements to improve devices reliability. Therefore, understanding the thermo-mechanical behavior of packaging polymers is critical for the development of packages. In order to be able to conduct process and structure optimization and to predict thermo-mechanical reliability more accurately and further to provide a base for virtual thermo-mechanical prototyping of electronic packaging, a fundamental understanding of the thermo-mechanical behavior of the packaging polymers and its influence on the reliability of the packages is imperative. Therefore, an appropriate material model should be established, and material characterization and numerical implementation should be carried out.In thesis [1], the authors used DMA experiments and timetemperature superposition to verify WLF equation and the viscoelastic model were available to characterize the electronic packaging polymers. Z. Xiong [2] point out that the epoxy molding compound is often modeled as an elastic material in the analysis of plastic-encapsulated IC package. However, many polymers

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Temperature Moisture and Mode Mixity Dependent EMC- Copper (Oxide) Interfacial Toughness

Xiao

Schlottig

Pape

et al. 2011

Experimental and Applied Mechanics, Volume 6

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Advanced viscoelastic material model for predicting warpage of a QFN panel

Cited by 20 publications

References 6 publications

Establishing fracture properties of EMC-Copper interfaces in the visco-elastic temperature region

Establishing fracture properties of EMC-Copper interfaces in the visco-elastic temperature region

Characterization, modelling, and parameter sensitivity study on electronic packaging polymers

Temperature Moisture and Mode Mixity Dependent EMC- Copper (Oxide) Interfacial Toughness

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