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October 1, 2017
Journal Article
Title
Non-Destructive Testing for System-in-Package Integrity Analysis
Abstract
The constant drive of microelectronics towards ever higher degrees of integration leads to a wide variety of concepts to yield smallest packages with maximized functionality – while side by side packaging leads to thinnest packages a small footprint can typically only be achieved by using component stacking
approaches. This leads to truly heterogeneous packages where a variety of materials are forming a complex potpourri of building blocks with different thermo-mechanical properties. While building such an integrated package needs high precision material dosing, component placement and fine pitch wire bonding and is already challenging – the non-destructive analysis of such packages for process and reliability characterization is even trickier. Additionally this NDT approach can not only be applied to determine the initial device quality but also during accelerated ageing tests as a tool for intermediate testing to determine the effects of chip-package interaction.
At Fraunhofer IZM a methodology has been applied to analyze a molded package using state of the art NDT equipment. A high resolution x-ray CT system by GE and a Gen6 CSAM system have been used as complimentary means to gain insight into a reference package that contains a four die stack assembled on PCB and is overmolded by a standard transfer molding process. To facilitate setting up the analysis procedure a variety of artefacts have been introduced to the package allowing the exact localization of layers and can be used to optimize the parameters for ultrasonic analysis for the variety of transducers used for package analysis. Additionally a simulation software is used to calculate the resulting ultrasound echoes for the different intra-package layers and the applicability of this tool for setting up an analysis procedure is provided.
As a result the paper describes an analysis methodology for highly integrated packages that uses CSAM analysis and x-ray CT for device analysis, while cross sectioning is used to confirm these results. Ultrasound simulation is applied to explain the findings of analysis process setup and will be evaluated on its potential to transfer the analysis method to SiP packages with varying geometry.
approaches. This leads to truly heterogeneous packages where a variety of materials are forming a complex potpourri of building blocks with different thermo-mechanical properties. While building such an integrated package needs high precision material dosing, component placement and fine pitch wire bonding and is already challenging – the non-destructive analysis of such packages for process and reliability characterization is even trickier. Additionally this NDT approach can not only be applied to determine the initial device quality but also during accelerated ageing tests as a tool for intermediate testing to determine the effects of chip-package interaction.
At Fraunhofer IZM a methodology has been applied to analyze a molded package using state of the art NDT equipment. A high resolution x-ray CT system by GE and a Gen6 CSAM system have been used as complimentary means to gain insight into a reference package that contains a four die stack assembled on PCB and is overmolded by a standard transfer molding process. To facilitate setting up the analysis procedure a variety of artefacts have been introduced to the package allowing the exact localization of layers and can be used to optimize the parameters for ultrasonic analysis for the variety of transducers used for package analysis. Additionally a simulation software is used to calculate the resulting ultrasound echoes for the different intra-package layers and the applicability of this tool for setting up an analysis procedure is provided.
As a result the paper describes an analysis methodology for highly integrated packages that uses CSAM analysis and x-ray CT for device analysis, while cross sectioning is used to confirm these results. Ultrasound simulation is applied to explain the findings of analysis process setup and will be evaluated on its potential to transfer the analysis method to SiP packages with varying geometry.
Author(s)