Environmental Stress Screening Research Articles

CMS ECAL VFE design, production and testing

Maintaining the required performance of the CMS electromagnetic calorimeter (ECAL) barrel at the High-Luminosity Large Hadron Collider (HL-LHC) requires the replacement of the entire on-detector electronics. 12240 new very front end (VFE) cards will amplify and digitize the signals of61200lead-tungstate crystals instrumented with avalanche photodiodes. The VFE cards host five channels of CATIA pre-amplifier ASICs followed by LiTE-DTU ASICs, which digitize signals with 160 MS/s and 12bit resolution. We present the strategy and infrastructure developed for achieving the required reliability of less than 0.5% failing channels over the expected lifetime of 20 years. This includes the choice of standards, design for reliability and manufacturing, as well as factory acceptance tests, reception testing, environmental stress screening and calibration of the VFE cards.

Optimizing nano/micro satellite constellation lifecycle cost based on reliability after acceptance testing

Constellation lifecycle costs are an important metric for constellation designers. Recurring costs of mega constellations in particular are large relative to the non-recurring costs, yet little attention has been given to the reduction of recurring costs. Moreover, few studies exist on the impacts of pre-launch activities such as satellite testing on subsequent operational reliability. We thus study the lifecycle cost impacts of environmental stress screening during acceptance testing to minimize constellation lifecycle costs. Parallels are drawn with the field of electronics testing, and costs arising from burn-in, replacement and availability are considered in our formulation. A single-objective cost minimization problem and a multi-objective cost and unavailability minimization problem are presented to capture different mission applications that require different objectives. The effects of system homogeneity and the use of sparing strategies are investigated. We propose genetic algorithms to solve the optimization problems and give some insight into how burn-in should be carried out for minimizing total costs. The optimization is also applied to a case study of a proposed mission scenario and the constellation lifecycle costs of an optimized burn-in plan are compared to those of a typical ”reliability target” burn-in plan. The optimization resulted in lifecycle cost savings of around 19% while significantly reducing the burn-in duration, showing much promise in the burn-in cost optimization approach.

제조공정 부적합 정보 기반 적응 ESS 시험 비용효과 최적설계 방법

Purpose: For manufacturers that do not specialize in military technology, it is often difficult to perform adequate environmental stress screening (ESS) tests. To address this challenge, we propose a novel adaptive ESS test that considers defect information from the manufacturing process.BRMethods: To create a suitable ESS profile for the electronic equipment of a weapon system and make it cost-effective, we developed a mathematical model that uses the modified US-military standards MIL-HDBK-344 and MIL-HDBK-2164.BRConclusion: To validate the effectiveness of the adaptive ESS test model, we performed a case study using the production of over-discharge protection circuits. The result of the analysis indicates that five of 21 samples exceeded the allowed defect density. To find the five samples, the new optimized test method was applied with the following test parameters (△T/ cycles/ test time): 1) 84.29 ℃/ 9/ 1293.36 min, 2) 69.82 ℃/ 2/ 258.57 min, 3) 82.22 ℃/ 13/ 1841.37 min, 4) 88.61 ℃/ 8/ 1184.11 min, 5) 88.20 ℃/ 5/ 738.03 min.

Environmental Stress Screening and Burn-in

The ESS evolved from burn-in techniques but is a considerably advanced process. Generally, ESS is an accelerated process of stressing a product in continuous cycles between predetermined environmental extremes, primarily temperature cycling plus random vibration. Burn-in is a generally lengthy process of powering a product at a specified constant temperature.

Failure Analysis of Electrical Equipment under Operational Vibration

Equipment is subjected to vibration due to operating environment, transportation, handling and earthquake. Vibration results in dynamic loading, wherein failure of equipment depends on magnitude and frequency content of vibration. Equipment should perform its desired function during and/or after the vibration. The need to understand the effects of vibration and shock on equipment reliability is paramount. Vibration qualification is performed to determine if a product can withstand the rigors of its intended use environment, to ensure the final design will not fall apart during shipping, for environmental stress screening to weed out production defects, or even as a form of accelerated stress testing. Vibration tests are commonly used to improve the reliability of instruments, sub components and equipment or a system. Earthquake is the natural disaster which results in three-dimensional ground vibrations. Failure analysis of electrical equipment subjected to operational vibration environment is presented in this paper.

Improved Complex Receiver System Design Strategies to Overcome EMI/EMC Challenges

This article analyzes various strategies and implementation techniques in detail for complex receiver system design to qualify Environmental Stress Screening (ESS) especially EMI/EMC tests for airborne system applications. Isolation of leakage energy between various RF/DC-DC converters/regulators/pulsing blocks are the key target of this design to keep conductive and radiative emission to a minimum. Hence, complex receiver design has been segregated into various modules. Then they are stacked together very tactfully within the specified area without compromising inter-channel/module interference between them and the form factor, respectively. The super compact stacks are further channelized for RF, DC supply, controls etc. and protected from any kind of interference. Low cost flexi interconnects are made to interface various stacks to arrest unwanted high/low frequency leakages. Proper layout, component placement, layer specific signal routing, and wire shielding have been used to protect low/high frequency reference clock, control signals, switching pulses, etc. from mixing. Processor boards with a DC supply unit are also integrated into the receiver as another stack and have been isolated from each other to qualify emission tests. Finally, four modules are developed and tested over temperatures of -40°C to +71°C (ESS) and EMI/EMC successfully to establish the methodology for mass production.

Practical Papers, Articles and Application Notes

RF receivers for airborne applications are critical systems for wireless signal reception and processing. Any unwanted interfering signals received by the receiver have a direct impact on the quality of the intended signals. The first paper, “Improved Complex Receiver System Design Strategies to Overcome EMI/EMC Challenges,” describes the strategies and implementation techniques for a complex receiver system design to meet environmental stress screening (ESS) requirements, especially EMC. The proposed design methodology segregates the various modules and stacks them together tactfully without compromising EMC. By applying these techniques, an actual design with four modules is demonstrated and tested for EMC compliance over an extreme temperature range from -40°C to +71°C.

Performance of Relays and Protection Equipment under Vibration Environment

Relays are the protection and switching devices in most of the control processes or equipment. Relays respond to one or more electrical quantities like voltage or current such that they open or close the contacts or circuits. Relays are subjected to vibration and mechanical shock due to operating environment, transportation, mishandling and earthquake. Operating environmental vibration and shock may result in spurious operation of relays. Understanding cause and effect of vibration on relay performance is paramount to ensure reliable functioning of relays. Relays should be designed for the anticipated operating environmental vibration and shock levels. Vibration and shock qualification is performed to determine if a product can withstand the rigors of its intended use environment, to insure the final design will not fall apart during shipping, for environmental stress screening and to weed out production defects. CPRI is equipped with state-of-the-art facilities to qualify equipment and components for vibration and shock conditions. Performance of relay under vibration environment is discussed in this paper.

Experimental verification and comparison of different tailoring models for spacecraft electronics thermal cycling tests

Thermal cycling tests (TCT) have been widely used for performance demonstration and reliability validation of the spacecraft electronics. The integrated tailoring model can provide customized testing conditions of TCT for different spacecraft electronics, which is different with the traditional unified tailoring model in MIL-STD-1540. Considering the influence of welding material, defect degrees and test levels, experimental verification had been done on solder samples. The evaluation indicators including test cost, simulation bias and simulation accuracy have been defined and compared between two different tailoring methods. The results show that for Sn/Pb solder samples, the testing effects of the two tailoring methods are the same. But for other materials solder samples, the integrated method can be used to achieve better environmental stress screening with lower cost than the traditional method. Such as the SAC solder, the simulation accuracy is increased by 0–10%, and the testing cost is decreased by 0–7%.

비용 효과도 최적화 기반 양산 무기체계 환경 부하 선별 시험 설계 방법

비용 효과도 최적화 기반 양산 무기체계 환경 부하 선별 시험 설계 방법

An integrated optimization framework for multi-cycle environmental stress screening tests and preventive maintenance scheduling

An integrated optimization framework for multi-cycle environmental stress screening tests and preventive maintenance scheduling is proposed. The proposed framework considers the improvement of product reliability through environmental stress screening tests and the associated screening cost, and the effect of preventive maintenance schedule on the maintenance cost as well. The environmental stress screening model is extended first to be applicable for multi-cycle environmental stress screening tests. The extended environmental stress screening model characterizes the product reliability function which survives the environmental stress screening test in terms of both the number of environmental stress screening cycles and the severity of screening stress. Afterwards, an integrated cost model is established by considering the cost of preventive maintenance, the cost of corrective maintenance, the cost of environmental stress screening test, and the cost due to failure of products in the environmental stress screening test. The application case study demonstrates the implementation procedures and the application effectiveness of the proposed approach. The application results show that, considering the cost due to environmental stress screening and the cost due to maintenance separately could lead to suboptimal decisions. For enterprises responsible for both environmental stress screening and maintenance, it is suggested to optimize the environmental stress screening test and maintenance scheduling jointly to minimize the overall cost.

Lagrangian approach to minimize makespan of non-identical parallel batch processing machines

This research is motivated by the testing operations conducted at an electronics manufacturing facility. Printed Circuit Boards (PCBs) of varying size are assembled on multiple assembly lines. The PCBs from different assembly lines are later grouped to form batches that are scheduled for testing on non-identical Environmental Stress Screening (ESS) chambers. The ESS chambers can process multiple PCBs simultaneously as long as the total size of all PCBs in the batch does not exceed the chamber’s capacity. The testing time of the batch depends on the composition of the batch. The chambers are referred to as Batch Processing Machines (BPMs) and PCBs are jobs in this paper. Scheduling non-identical BPMs to minimize the makespan objective is known to be NP-hard. Consequently, the Particle Swarm Optimization (PSO) and Random Keys Genetic Algorithm (RKGA) approaches were proposed in the literature. In this research, a Lagrangian Relaxation (LR) approach is proposed. The solution from the LR approach is compared to the solution from PSO, RKGA, and a commercial solver. An experimental study is conducted on benchmark instances and the LR approach identified a new improved solution for several problem instances.

생산 공정 자료 기반 양산단계 전차 전장관리체계 환경 부하 선별 시험 방법 및 적용 개선에 관한 연구

생산 공정 자료 기반 양산단계 전차 전장관리체계 환경 부하 선별 시험 방법 및 적용 개선에 관한 연구

Environmental stress screening modelling, analysis and optimization

Environmental stress screening (ESS) is widely used in industry to eliminate early or latent failures. However, the appropriate stochastic modeling for ESS has not been yet suggested in the literature. In this paper, we develop the corresponding stochastic model and analyze the effect of the ESS in terms of population characteristics. In our model, during the ESS, the manufactured items are exposed to a stress with the relatively large magnitude, which can result either in immediate failures of items or in the increased susceptibility to future failures. The corresponding optimization problems for obtaining the optimal level of the stress magnitude are also formulated and discussed. An illustrative example is considered.

Assessment of Solder Joint Fatigue Life Under Realistic Service Conditions

The behavior of lead-free solder alloys under complex loading scenarios is still not well understood. Common damage accumulation rules fail to account for strong effects of variations in cycling amplitude, and random vibration test results cannot be interpreted in terms of performance under realistic service conditions. This is a result of the effects of cycling parameters on materials properties. These effects are not yet fully understood or quantitatively predictable, preventing modeling based on parameters such as strain, work, or entropy. Depending on the actual spectrum of amplitudes, Miner’s rule of linear damage accumulation has been shown to overestimate life by more than an order of magnitude, and greater errors are predicted for other combinations. Consequences may be particularly critical for so-called environmental stress screening. Damage accumulation has, however, been shown to scale with the inelastic work done, even if amplitudes vary. This and the observation of effects of loading history on subsequent work per cycle provide for a modified damage accumulation rule which allows for the prediction of life. Individual joints of four different Sn-Ag-Cu-based solder alloys (SAC305, SAC105, SAC-Ni, and SACXplus) were cycled in shear at room temperature, alternating between two different amplitudes while monitoring the evolution of the effective stiffness and work per cycle. This helped elucidate general trends and behaviors that are expected to occur in vibrations of microelectronics assemblies. Deviations from Miner’s rule varied systematically with the combination of amplitudes, the sequences of cycles, and the strain rates in each. The severity of deviations also varied systematically with Ag content in the solder, but major effects were observed for all the alloys. A systematic analysis was conducted to assess whether scenarios might exist in which the more fatigue-resistant high-Ag alloys would fail sooner than the lower-Ag ones.

Stochastic Modeling for Environmental Stress Screening

Environmental stress screening (ESS) of manufactured items is used to reduce the occurrence of future failures that are caused by latent defects by eliminating the items with these defects. Some practical descriptions of the relevant ESS procedures can be found in the literature; however, the appropriate stochastic modeling and the corresponding thorough analysis have not been reported. In this paper we develop a stochastic model for the ESS, analyze the effect of this operation on the population characteristics of the screened items, and also consider the relevant optimization issues.

Stochastic Modeling for Environmental Stress Screening

Environmental stress screening (ESS) of manufactured items is used to reduce the occurrence of future failures that are caused by latent defects by eliminating the items with these defects. Some practical descriptions of the relevant ESS procedures can be found in the literature; however, the appropriate stochastic modeling and the corresponding thorough analysis have not been reported. In this paper we develop a stochastic model for the ESS, analyze the effect of this operation on the population characteristics of the screened items, and also consider the relevant optimization issues.

The Analysis of Some Problems of Environmental Stress Screening of Electronic Equipment

This article analyses the importance of equipment environment screen (ESS), and analyses the intention, demand and trait of the ESS, and the relatives between ESS and equipment experiment. Besides, it analyses the ESS implement project of printed board, electronic assembly system under the screen of temperature cycle test and random shake environment, and draw some benefiting conclusion.

방향 탐지용 대공 근접 신관센서의 BPSK 송수신기 설계에 관한 연구

This paper describes the fundamentals, design, realization and test results of a BPSK(Bi Phase Shift Keying) transceiver for the direction finding proximity fuze sensor for anti-aircrafts or air missiles. The BPSK transceiver for the direction finding fuze sensor has been designed to detect a moving target by Doppler signal processing with the code correlation method and to distinguish direction by comparing received powers of each Doppler signal from adjacent three receiving antennas. The electrical and ESS(Environmental Stress Screening) tests of the BPSK transceiver showed satisfactory results and target detection and direction finding performances proved to be successful through dynamic operation tests by 155 mm gun firing.

전자장비 신뢰성 향상을 위한 ESS 프로세스 모델링 및 적용에 관한 연구

Defense Agency for Technology and Quality(DTaQ) Purpose: In this study, we propose the ESS process model which, in order to improve reliability of electronic equipment, can be referenced in both development and production phases.Methods: ESS guidelines such as MIL handbooks or private sector ESS gui delines are used for devising the proposed ESS model. Especially, proposed model is customized by using those references in order to be optimized in the domestic development and production phases.Results: ESS-related-requirements which is specified in the Technical D ata Package(TDP) for the area of guided missile systems are analyzed. Current status of the requ irement and screening strength are analyzed for those systems to show what kind of weak points should be im proved.Conclusion: A ESS guideline which is applicable to the domestic weapon acq uisition environment is proposed. As such, the necessity and detail guidelines of the proposed mo del are explained.Key Words：Environmental Stress Screening(ESS), ESS profile, ran dom vibration, thermal cycling, Technical Data Package(TDP)