Use of high temperature operating life data to mitigate risks in long-duration space applications that deploy commercial-grade plastic encapsulated semiconductor devices
Abstract Commercial-grade plastic encapsulated semiconductor devices are now widely used in space and military equipment for their cost-per-performance and availability advantages over military type ceramic parts. However, many equipment manufacturers still perceive risks in their deployment, and conduct expensive and time-consuming screening and qualification programs to mitigate the potential risks associated with their use. This paper discusses the limitations of the screening and qualification approach currently employed by space equipment manufacturers to assess the long-term reliability of commercially-available plastic encapsulated semiconductor devices (PEDs) in deep space missions. In addition, the paper presents the value of the high temperature operating life (HTOL) data published by manufacturers of PEDs for mitigating the risks associated with the use of such devices in long-duration space applications, where steady-state temperature is the significant stress parameter.
Reliability assessment of electronic components exposed to long-term non-operating conditions
The decreased availability of MIL-SPEC components is forcing designers of low volume complex electronic systems, such as avionics and defense electronics, to consider the use of commercial off-the-shelf plastic encapsulated microcircuits (COTS PEMs). Traditionally, designers of these long-life, high reliability systems have been reluctant to use COTS PEMs because of concerns related to their capability to survive in harsh environments over long periods of continuous or intermittent operation. Many commercial insertion studies in the last several years have now conclusively demonstrated that PEMs made using best commercial materials, processes, and quality techniques will permit devices to perform reliably in the most severe environments. However, only recently have studies focused on the reliability of PEMs in that subset of applications requiring short time operation after long periods of unpowered storage (10 to 20 yrs). This paper presents the results of five critical commercial insertion studies focusing on long term storage reliability. These studies include analysis of PEMs, hermetic microcircuits, and assemblies stored for up to 28 yrs in various storage locations around the world. Regardless of the storage conditions, commercial grade PEMs, without screening or incoming inspection, survived assembly and extended storage, even though, in some cases, degradation was observed on the boards.
Implementation of Tourism Satellite Account: Assessing the Contribution of Tourism to the Croatian Economy
Compiling the indicators of tourism consumption and the output of tourism industries, Tourism Satellite Account (TSA) provides a framework for internationally harmonized measurements of direct macroeconomic contribution of tourism. Ivandic and Marusic provide a detailed methodological approach for the transfer of TSA theoretical concepts to the assessment of tourism economic contribution on the case of the Croatia. Giving that the TSA compilation is still characterized by a surprisingly wide range of ‘styles’ used, the chapter contributes to a better understanding of the issues related to measurement of direct tourism impacts. It also gives a set of baseline criteria for resource allocation within tourism policy and the further evaluation of its effectiveness.