Burn-in Policy Research Articles

Optimal burn‐in decision making

This paper presents a conceptual model of burn-in decision making which gives an optimal burn-in time for semiconductor devices and describes how burn-in affects total yield and reliability. For the gate oxide of integrated circuits we consider four burn-in policies: no burn-in, wafer-level burn-in only, package-level burn-in only and wafer-level burn-in prior to package-level burn-in. A decision-making model to minimize cost is given for each burn-in policy. Burn-in time is strongly limited by the cost factor and reliability requirements. In order to reduce the cost incurred in burn-in, a short test time and small test samples are recommended. Copyright © 1998 John Wiley & Sons, Ltd.

Bathtub failure rate and upside-down bathtub mean residual life

This paper shows that: (1) the mean residual life (MRL) of a component has an upside-down bathtub-shape if the component has a bathtub-shape failure-rate function, but the converse does not hold; and (2) there is an optimal burn-in policy to maximize the MRL when the underlying lifetime distribution has a bathtub-shape failure rate. >

Burn-in and Maintenance Policies

Burn-in is a widely used method to improve quality of products after they have been produced. For a repairable component there are two common types of repair, complete repair and minimal repair. Preventive maintenance policies such as age replacement and block replacement are often employed in field operation. The present paper takes burn-in, maintenance and repair into consideration at the same time and considers related cost structures. The properties of the corresponding optimal burn-in times and optimal maintenance policies are discussed.

OPTIMAL BURN-IN SIMULATION ON HIGHLY INTEGRATED CIRCUIT SYSTEMS

Bum-in, a screening technique to improve product reliability, is especially useful for highly integrated circuit systems. But, in most applications, the resulting systems reliability after burn-in is worse than what has been forecasted, because of “incompatibility” not only among components but also among different subsystems and at the system level. To deal with this phenomenon, we present a simulation method to compensate for the lack of field data. Also, a stress-strength model is implemented using weighted factors and a model based on nonlinear programming theory is designed to find the optimal burn-in policy that satisfies the reliability requirement and cost restriction. The program presented here can serve as an “IC Information Query System” for system designers to consider at the design stage.

Processor Tradeoffs in Distributed Real-Time Systems

Optimizing the design of real-time distributed systems is important since the systems are frequently critical to life. This optimization is a difficult problem, and heuristics and designer judgment are called for in the process. The chief cause of the difficulty is the large number of parameters under the designer's control which impact performance and life-cycle cost. We study the interplay between the more important parameters in this paper using two objective measures, i. e., the mean cost and the probability of dynamic failure in [6], [10]. Among these are the processor burn-in time and processor replacement policy. A central feature of this work is a look at how the application requirements affect the optimality of the distributed systems; indeed, the application requirements are an integral part of the analysis.

Case studies in system burn-in

This paper describes the results of several burn-in experiments carried out within the Danish industry. The systems considered range from printed circuit boards to complex electronic equipment containing 4000 components. The experiments were conducted in an effort to find a consistent pattern of early failures, which could be used to plan economical burn-in procedures. The failure patterns were recorded on Weibull paper, for ease of analysis. Most of the systems showed a very strong early failure pattern, indicating a subpopulation of ‘weak’ systems. Using the concept of bimodal distributions of the lifetimes of the ‘rogue’ components within the systems, it is possible, in some cases, to compute the early failure pattern of the systems. This technique is briefly described in this paper. Finally, the economic consequences of performing equipment or system burn-in are discussed and an optimal burn-in policy is considered.

Cost Effective Burn-In and Replacement Times

Bum-in and replacement policies have been used to reduce the cost of maintaining a system function. Existing solutions to the burn-in and the combined burn-in, replacement problems are typically difficult to apply. A simpler solution to this problem is given. The only distributional property required is the reliability function. Thus either parametric or nonparametric estimates of reliability can be used in the solution. The nonparametric solution is appealing in the case of a combined burn-in and replacement policy because the U shaped failure rate makes parametric estimation of reliability difficult.