The reliability of a product is generally concerned with failures during its operating life. Accelerated (stress) burn‐in before shipment will reject poor quality products and avoid a high initial mortality rate in residual life. It is justified when the expected proportion of a product being defective is high in the infant stage and where early removal of defects will improve reliability in service. Studies economic designs of stress screening plans where every finished product is subject to burn‐in. Examines the optimal burn‐in time in minimizing total testing, manufacturing, quality and reliability costs. Discusses the effect of burn‐in stress level.
Burn‐in is an engineering method extensively used to screen out infant mortality failure defects. Previous studies have attempted to determine the optimum burn‐in time and…
Burn‐in is an engineering method extensively used to screen out infant mortality failure defects. Previous studies have attempted to determine the optimum burn‐in time and cost for a device or a system. However, for the mathematical model, many assumptions are inappropriate due to practical concerns, and for the cost model, the required costs are difficult to find. How to effectively determine the optimal burn‐in time and cost has perplexed manufacturers for quite some time. In the actual manufacturing process, a new electronic product is always extended from an old product, called the base product. By adopting the relationship between new product and base product, this study presents a neural network‐based approach to determine the optimal burn‐in time and cost without any assumptions. A case study of the production of a switch mode rectifier demonstrates the effectiveness of the proposed approach.
Presents a cost‐optimization model for determining optimal burn‐in times at the module/system level of an electronic product. Optimum burn‐in is determined as that which…
Presents a cost‐optimization model for determining optimal burn‐in times at the module/system level of an electronic product. Optimum burn‐in is determined as that which will be most cost‐effective when considering burn‐in cost, field failure savings and the impact on system reliability.
Burn‐in is an effective means of screening out the infant mortality components of a system. Most related studies investigated burn‐in by curve fitting for a failure model…
Burn‐in is an effective means of screening out the infant mortality components of a system. Most related studies investigated burn‐in by curve fitting for a failure model and cost for an optimal burn‐in time model and environmental stress model. However, those investigations did not provide an effective method to determine the optimal burn‐in condition for a practical operation. As a result, this study presents an effective procedure that uses part stress analysis and robust design techniques to determine the optimal burn‐in operational environment. A case study of the production of a switch mode rectifier is performed and compared with the traditional approach, to examine the proposed procedure’s effectiveness. Those results show that the proposed procedure generalizes well, and can screen out the early failure of material and manufacturing process.
To investigate the optimal burn‐in time from the perspective of minimizing the expected total cost (i.e. manufacturing plus warranty costs) per unit of product sold under…
To investigate the optimal burn‐in time from the perspective of minimizing the expected total cost (i.e. manufacturing plus warranty costs) per unit of product sold under a failure‐free renewing warranty policy. The conditions indicating when burn‐in becomes beneficial were also derived.
An age‐dependent general repairable product sold under a failure‐free renewing warranty agreement was considered. In the case of such a general repairable model, there are two ways in which the product can fail: type I failure (minor) can be rectified through minimal repairs; while in type II failure (catastrophic), the product must be replaced. Then optimal burn‐in time is then examined in order to achieve a trade‐off between reducing the warranty cost and increasing the manufacturing cost.
The optimal burn‐in time depends on the failure/repair characteristics, length of warranty, cost parameters and the probability of failure type II (catastrophic). A burn‐in program is beneficial if the initial failure rate is high or product failures during the warranty period are costly. Moreover, the optimal burn‐in time is always less than the infant mortality period.
The product considered in this paper is an age‐dependent general repairable product: on which no such study has yet been conducted. This is also the first study to apply a failure‐free renewing warranty to a general repairable item. It can be seen that the present model is a generalization of the model considered by Chien and Sheu.
Known good die (KGD) have been available, primarily for use in hybrids, for many years. The MCM industry is now becoming the driving force for new standards of die quality…
Known good die (KGD) have been available, primarily for use in hybrids, for many years. The MCM industry is now becoming the driving force for new standards of die quality that may only be achieved by individual die test and burn‐in. High yielding MCM designs will depend on fully tested die being available. This paper examines the progress of known good die from its beginnings over 15 years ago to the methods now available for screening of die including various types of temporary die carrier. The survey also looks at the future of mass KGD using wafer level burn‐in and test. The success of KGD depends on choosing the correct screening option for a particular product to balance quality and cost. Selection criteria are therefore included for five main levels of KGD, each using a different screening technique. Also included is an overview of the temporary die carriers from TI/MMS and from National Semiconductors.
Hybrid manufacturers are uncertain as to whether laser‐drilled holes on 96% alumina are suitable for mixed‐bonded thick film conductor metallisation, or whether they…
Hybrid manufacturers are uncertain as to whether laser‐drilled holes on 96% alumina are suitable for mixed‐bonded thick film conductor metallisation, or whether they require further treatment before metallisation if reliable circuitry is to be produced. Moreover, although the metallisation of holes on ceramic through the use of screen printed thick films is fairly common in the hybrid industry, this paper shows that published information on this topic is scant, at times contradictory, and, because of proprietary constraints, generally of little use. The authors report on an extensive study in which both as‐laser‐drilled holes and thermally‐treated laser‐drilled holes are metallised using a mixed bonded Pd‐Ag conductor paste. Both encapsulated and non‐encapsulated metallised holes are then subjected to various accelerated life tests, followed by ‘power‐up’ tests to the extreme of circuit destruction. An account is also given of a printing set‐up which allows volume production of printed through‐holes without the need for special skill or attention on the part of the printing operator.
The authors consider a system which is a part of a complex equipment (e.g. aircraft, automobile, medical equipment, production machine, etc.), and which consists of N…
The authors consider a system which is a part of a complex equipment (e.g. aircraft, automobile, medical equipment, production machine, etc.), and which consists of N independent series subsystems. The purpose of this paper is to determine simultaneously the system design (reliability) and its preventive maintenance (PM) replacements periodicity which minimize the total average cost per time unit over the equipment useful life, taking into account a minimum required reliability level between consecutive replacements.
The problem is tackled in the context of reliability-based design (RBD) considering at the same time the burn-in of components, the warranty commitment and the maintenance strategy to be adopted. A mathematical model is developed to express the total average cost per time unit to be minimized under a reliability constraint. The total average cost includes the cost of acquiring and assembling components, the burn-in of each component, preventive and corrective replacements performed during the warranty and post-warranty periods. A numerical procedure is proposed to solve the problem.
For any given set of input data including components reliability, their cost and the costs of their preventive and corrective replacements, the system design (reliability) and the periodicity of preventive replacement during the post-warranty period is obtained such as the system’s total average cost per time unit is minimized. The obtained results clearly indicate that a decrease in the number of PM actions to be performed during the post-warranty period increases the number of components to be added at each subsystem at the design stage.
Given that the objective function (cost rate function) to be minimized is non-linear and involves several integer variables, it has not been possible to derive the optimal solution. A numerical procedure based on a heuristic approach has been proposed to solve the problem finding a nearly optimal solution for a given set of input data.
This paper offers to manufacturers a comprehensive approach to look for the most economical combination of the reliability level to be given to their products at the design stage, on one hand, and the PM policy to be adopted, on the other hand, given the offered warranty and service for the products and reliability requirements during the life cycle.
While the RBD problem has been largely treated, most of the published works have focussed on the development or the improvement of solving techniques used to find the optimal configuration. In this paper the authors provide a more comprehensive approach that considers simultaneously RBD, the burn-in and warranty periods, along with the maintenance policy to be adopted. The authors also consider the context of products whose component failures cannot be rectified through repair actions. They can only be fixed by replacement.
THE reliability of ICs and other semi‐conductors is a subject which continues to challenge both manufacturers and users. “High specification” markets such as the Avionics Sector, lead the user demand for a greater degree of assurance that the products they install demonstrate a longer and more effective life. The percentage of DOA (dead on arrival) components has become less but, nevertheless, Burn‐in of standard devices, or even re‐screening of those supplied as “high rel”, remain important activities in the manufacture of electronic assemblies — and a benefit to the user of the final product. Early failures, also known as “infant mortalities” and the concern for extended life in components, creates an element of worry in the minds of those companies whose products are required to provide high MBTFs, extended operational life and minimum risk of failure.