Purpose

This paper aims to present an adaptation of digital image correlation (DIC) to the electronics industry for reliability assessment of electronic packages. Two case studies are presented: one for warpage measurement of a micro-electro-mechanical system (MEMS) package under different temperature conditions and the other for the measurement of transient displacements on the surface of a printed circuit board (PCB) assembly under free-fall drop conditions, which is for explaining the typical camera setup requirement and comparing among different boundary conditions by fastening methods of PCB.

Design/methodology/approach

DIC warpage measurements on a small device, such as a MEMS package, require a special speckle pattern. A new method for the creation of speckle patterns was developed using carbon coating and aluminum evaporative deposition. To measure the transient response on the surface of a PCB during a free-fall impact event, three-dimensional (3D) DIC was integrated with synchronized stereo-high speed cameras. This approach enables the measurement of full-field displacement on the PCB surface during a free-fall impact event, contrary to the localized information that is obtained by the conventional strain gage and accelerometer method.

Findings

The authors suggest the proposed patterning method to the small-sized microelectronics packages for DIC measurements. More generally, the idea is to have a thin layer of the dark or bright color of the background and then apply the white or black colored pattern, respectively, so that the surface has high contrast. Also, to achieve a proper size of speckles, this paper does not want to expose the measuring objects to high temperatures or pressures during the sample preparation stage. Of course, it seems a complicated process to use aluminum evaporator, carbon coater and electroformed mesh. However, the authors intend to share one of the solutions to achieve a proper pattern on such small-sized electronic packages.

Originality/value

3D DIC technique can be successfully implemented for the measurement of micro-scale deformations in small packages (such as MEMS) and for the analysis of dynamic deformation of complex PCB.

中文翻译：

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先进地利用3D数字图像相关性来提高电子元件的热可靠性和冲击可靠性

目的

本文旨在提出一种适用于电子行业的数字图像相关性（DIC），用于电子封装的可靠性评估。提出了两个案例研究：一个用于在不同温度条件下微机电系统（MEMS）封装的翘曲测量，另一个用于在自由温度下测量印刷电路板（PCB）组件表面的瞬态位移。跌落条件，用于说明典型的相机设置要求，并通过PCB的固定方法在不同的边界条件之间进行比较。

设计/方法/方法

在诸如MEMS封装之类的小型设备上进行DIC翘曲测量需要特殊的斑点图案。利用碳涂层和铝蒸发沉积，开发了一种用于创建斑点图案的新方法。为了测量自由落体冲击事件期间PCB表面的瞬态响应，将三维（3D）DIC与同步立体声高速相机集成在一起。与传统的应变计和加速度计方法获得的局部信息相反，这种方法能够在自由落体冲击事件期间测量PCB表面的全场位移。

发现

作者建议将所提出的构图方法应用于小型微电子封装，以进行DIC测量。更一般地，该想法是使背景的暗色或亮色具有薄层，然后分别施加白色或黑色图案，从而使表面具有高对比度。另外，为了获得适当的斑点大小，本文也不想在样品制备阶段将测量对象暴露在高温或高压下。当然，使用铝蒸发器，碳涂层机和电铸网似乎是一个复杂的过程。但是，作者打算共享一种解决方案，以在这种小型电子封装上实现合适的图案。

创意/价值

3D DIC技术可以成功地用于测量小尺寸封装（例如MEMS）中的微尺度变形以及分析复杂PCB的动态变形。