Quantitative Evaluation of Strength Degradation at Interfaces in IC Packages and Formulation of a Fundamental Mechanical Device Reliability Strategy

包装组件中的接口，在处理和服务过程中识别分层。 提出了一种设计和预测这些接口的机械可靠性的基本方法，以期取代目前的经验和相当耗时的方法，利用加速测试协议。 所提出的策略的实施需要（1）开发能够在实际器件和封装结构中原位测试界面的基本界面强度测量工具，（2）原位测量作为湿度、温度和时间变量的函数的所选界面的拉伸强度，和（3）使用FTIR和热重分析对每个测试样品的水分含量进行定量。 这些将产生“界面强度图”，用于预测在不同湿度和温度条件下选定界面的降解。 开发良好的仿真代码然后可以预测封装组件内的任何接口处的应力集中、湿气积聚和温度上升，以确定（a）在任何IC制造和封装之前，接口是否能够在设计阶段本身期间经受住处理和系统集成周期，以及（B）在制造时为确保规定的使用寿命所需的界面强度水平。 上述过程将首先通过研究Si 3 N4/Si 3 N4钝化层界面来演示。 界面抗拉强度的测量，原位，将通过修改激光溅射方法，由PI以前开发完成。

Interfaces in package assemblies where delaminations during processing and service are identified. A fundamental approach for designing and predicting the mechanical reliability of these interfaces is proposed, with a view to replace the current empirical and rather time-consuming approaches that utilize accelerated test protocols. Implementation of the proposed strategy requires (1) the development of a fundamental interface-strength-measuring tool capable of testing interfaces, in-situ, in actual device and package structures, (2) measurement of the tensile strength, in-situ, of the selected interface as a function of humidity, temperature, and time variables, and (3) quantification of the moisture content using FTIR and thermogravimetric analyses on each tested sample. These will result in "interface strength charts" for predicting degradation at the selected interface for varying humidity and temperature conditions. Well developed simulation codes can then predict stress concentrations, moisture accumulation, and temperature rise at any of the interfaces within the package assembly for determining (a) whether the interface will be able to survive processing and system integration cycles during the design phase itself, prior to any IC fabrication and packaging, and (b) the level of interface strength needed at the time of manufacturing for ensuring a prescribed service life. The above procedure will first be demonstrated by studying the underfill/Si3N4 passivation layer interface. Measurement of the interface tensile strength, in-situ, will be accomplished by modifying a laser spallation method, developed previously by the PI.