Testing And Burn-in Screening Technology Of Power Bare Die

The power bare die has applied widely in power modules of electronic system such as automobile and domestic electronic appliances and so on.To ensure the reliability of the bare die is the key to enhance the pass-rate of the products. The paper studied principally the testing and burn-in screening technology of power bare die in order to improve the quality and reliability.The power bare die has the characteristic of large operating current and high operating temperature when we test or screen it, we have made the suitable improvement to the carrier system, and have carried on the reliable confirmation analysis with it. Experiment results have shown that the conduct resistance of the new carrier decrease significantly, the contact resistance of the new substrate with the large-size and multi-bump decreases by 40%, it decreases thermal dissipation gross. We replace the plastic cover board by copper cover board to strengthen the radiation ability of the carrier system. The results have shown that the endured current capacity of the carrier increases from less than 2.5A to 3A above. Through analyzing the impact pressure to the conduct resistance, combined with the bare die's damnification,we confirm an appropriate contact pressure . Experiment results have shown that both the thermal dissipation power and the utmost current and anti-impact capability of the carrier have distinct improvement.After completing the carrier system development, the most important question is to confirm an appropriate screening plan. Through researching failure mechanism of the power bare die, we confirm basic conditions of the reliability test, such as screening projects, the screening stress conditions, the failure criterion and the screening procedure. In the screening methods, the electric power burn-in method is considered the most effective method, but we need to prevent the phenomenon of the screening stress insufficiency or over. After profound researching the methods and control technology of the junction temperature measurement, we indicate the disadvantages of normal linear approximatively method and propose a more effective method. The new method improve the accuracy of the junction temperature measurement.Finally,we we has completed the burn-in screening power bare chip through the peak value junction temperature method and carried on the validity check through the probe test.After measuring and controlling the junction temperature, there are two kinds of burn-in screening methods for power bare die, besides the peak value junction temperature burn-in screening method which introduced in this article, the method called full capacity continual pulse burn-in screening method also can be considered, which is the study topic in the future.