Nils F. Nissen

3-D Thin film interposer based on TGV (Through Glass Vias): An alternative to Si-interposer

Interposers for SiP will become more and more important for advanced electronic systems. But through substrate vias are essential for the 3-D integration. Being a standard for laminate based materials this is much more complex for Si-wafers: High speed etching has to be combined with complex electrical isolation, diffusion barriers and void-free Cu-filling. Without doubt this can be solved in lab-scale but for high production scale cost is a tremendous barrier. Glass wafers with W-plugs have been intensively investigated in this paper. A new acronym has been posted to high-light this technology: TGV for Through Glass Vias. The results of modeling and simulation of TGV at RF/Microwave frequencies showed a very good compromise between wafer thickness, TGV-shape and via diameter for vertical metal plugs with 100 μm diameters in 500 μm thick glass wafer still very stable for thin film wafer processing without costly temporary wafer bonding processes. Therefore the HermeS® from Schott was chosen as the basis for a prototype of a bidirectional 4 × 10 Gbps electro-optical transceiver module. Thin film RDL and bumping of these wafers was possible without any modifications to Si-wafer. First thermal cycles showed very promising results for the reliability of this concept.

Data availability and the need for research to localize, quantify and recycle critical metals in information technology, telecommunication and consumer equipment

The supply of critical metals like gallium, germanium, indium and rare earths elements (REE) is of technological, economic and strategic relevance in the manufacturing of electrical and electronic equipment (EEE). Recycling is one of the key strategies to secure the long-term supply of these metals. The dissipation of the metals related to the low concentrations in the products and to the configuration of the life cycle (short use time, insufficient collection, treatment focusing on the recovery of other materials) creates challenges to achieve efficient recycling. This article assesses the available data and sets priorities for further research aimed at developing solutions to improve the recycling of seven critical metals or metal families (antimony, cobalt, gallium, germanium, indium, REE and tantalum). Twenty-six metal applications were identified for those six metals and the REE family. The criteria used for the assessment are (i) the metal criticality related to strategic and economic issues; (ii) the share of the worldwide mine or refinery production going to EEE manufacturing; (iii) rough estimates of the concentration and the content of the metals in the products; (iv) the accuracy of the data already available; and (v) the occurrence of the application in specific WEEE groups. Eight applications were classified as relevant for further research, including the use of antimony as a flame retardant, gallium and germanium in integrated circuits, rare earths in phosphors and permanent magnets, cobalt in batteries, tantalum capacitors and indium as an indium–tin-oxide transparent conductive layer in flat displays.

Environmental assessments of electronics: a new model to bridge the gap between full life cycle evaluations and product design

In this paper summaries and comparisons of different approaches for the environmental assessment of electronics are presented. A new assessment model developed at the IZM is explained, which is based on the material content of a product instead of the complete life cycle process chain. Comparisons with other simplified indicator systems and with complex life cycle methods such as those according to SETAC or EPS are made. Emphasis is put on the user needs and the data acquisition problems for each approach and on the usability of the results in the design of electronic products.

glassPack — A 3D glass based interposer concept for SiP with integrated optical interconnects

We introduce thin glass for electrical-optical integration on module level. Glass is regarded as promising material for high frequency wiring to drive the e/o components having additional advantages in terms of transparency, waveguide and lens integration capability and PCB integration. Modeling results of vertical and horizontal electrical interconnects show the suitability for certain configurations. The integration schemes will be discussed and experimental results from thin film deposition, laser drilling of through vias and ion exchange for optical waveguides will be presented.

EE-Toolbox-a modular assessment system for the environmental optimization of electronics

Electronic products are so complex and fast evolving that specific life cycle analysis (LCA) during the product development are still not feasible. One successful alternative is a modular evaluation concept. The spectrum of companies in electronics-from the small, specialized company where one person handles all environmental affairs to the global players with their own environmental research departments-requires a flexible mixture of basic research and reliable data generation, contract R&D, and the transfer of results and methods into management workflows. Several electronic systems mainly from information and communications products have been assessed with a different number of modules, depending on the expected or necessary width and depth of results. For all examples optimization strategies and specific improvements will be shown.

An environmental comparison of packaging and interconnection technologies

Packaging and interconnection are driving forces behind the miniaturization of electronics. Since miniaturization means less use of resources this trend seems inherently environmentally benign. Adverse effects may overlay this simple truth. The investments for new production facilities rise, the complexity and closeness of non-separable compounds in electronic products increase and the amount and applications of electronic goods multiply. The goal must be to influence new technology developments as early as possible to ensure that the balance of the listed effects remains positive for the environment. As a first step in this direction a simple comparison of different interconnection options is made which is based on the material content of the different printed circuit board assemblies.

Glass carrier based packaging approach demonstrated on a parallel optoelectronic transceiver module for PCB assembling

Glass as a carrier material for electrical and optical interconnects has many benefits compared to conventional materials like silicon, ceramic or polymer based laminates because of its excellent dielectric and transparent properties that are becoming important for electrical high-frequency signal wiring as well as for optical wave guiding. Furthermore, the integration potential of glass is excellent because of the dimensional stability under thermal load and the coefficient of thermal expansion matching that of silicon ICs. A small pitch size of conductor traces, small scale through-vias and high alignment accuracy are the key requirements that will be achieved from glass carrier based packaging. Another outstanding benefit is the transparency of glass that allows the planar integration of optical waveguides inside the glass core material and the light transmission through the carrier between different optical layers. This paper presents a four channel bi-directional optoelectronic transceiver module that was designed and processed using the glass carrier based packaging approach called glassPack. The transceiver operates with 10 Gbps per channel and has an extremely low power consumption of 592 mW. The module is mounted on a printed circuit test board and the performance is characterized by bit error rate testing.

Environmental performance of mobile products

Digitalization, miniaturization and integration are strong drivers for further development of products for mobile communication. As such these will generally lead to lower environmental loads per product. However, the strongly increasing number of products on the market will reverse this trend for the total sector. Examinations on telephones have been carried out jointly at Philips Consumer Electronics and at the Fraunhofer Institute for Reliability and Microintegration (IZM). The characteristic product parts, energy supply, display, encasing and electronic signal processing are subjected to an environmental assessment (including environmental assessment with Eco-Indicator and with the Toxic Potential Indicator IZM-TPI) and improvement potentials are shown for the selected products. The analysis shows that in mobile products, energy systems and the printed circuit boards are the key elements in further reduction of environmental loads. Both alternative substrates, lead free soldering and component selection (less hazardous substances) can contribute substantially towards this goal. These three topics are combined with further miniaturization, especially reduction of the board size, in the future. Approximately only half of the potential in this field has been implemented yet. As an overall result, it is concluded that the environmentally based load of present and future mobile products can be kept within limits if a swift implementation of EcoDesign (design for environment) is ensured.

A solder joint fatigue life model for combined vibration and temperature environments

Electronic assemblies in field use are exposed to a wide range of environmental loads. The interaction of combined loads has to be considered in lifetime estimates of electronic packages. In this paper, we discuss lifetime prediction for lead-free soldered flip chips under vibration load in different temperature environments in terms of solder joint fatigue. Parameters for lifetime modeling are obtained from non-linear and temperature-dependent finite element analysis and lifetime experiments. We introduce temperature dependent coefficients and exponents for the Coffin-Manson-Basquin relationship considering elastic and plastic fatigue behavior. The results indicate that temperature is an important parameter affecting the solder joint vibration fatigue life.

Environmental comparison of energy scavenging technologies for self-sufficient micro system applications

The implementation of energy scavenging technologies in distributed, self-sufficient micro systems offers new approaches to the realization of long-time power supplies within reasonable system dimensions. In this article various technical solutions to supply a low-power micro system with basic functions and fixed energy requirements are examined from an environmental point of view. Based on the material composition of state-of-the-art scavengers accurately described in literature, the toxic content of these devices is evaluated and compared to the long-term use of a primary lithium battery. Environmental impact of the various technical approaches is discussed on the basis of the results.