A Case Study on Evaluating Manual and Automated Heat Sink Assembly using FEA and Testing


Reading time ( words)

Proper assembly of components is critical in the manufacturing industry as it affects functionality and reliability. In a heat sink assembly, a detailed manual process is often utilized. However, an automated fixture is used whenever applicable. This paper will illustrate the use of strain gauge testing and finite element analysis (FEA) as a simulation tool to evaluate and optimize the heat sink assembly process by manual and automated methods.

Several PCBAs in the production line were subjected to the manual and automated assembly process. Strain gauge testing was performed and FEA models were built and run. Results were compared with the goal of improving the FEA model. The updated FEA model will be used in simulating different conditions in assembly. Proposed improvement solutions to some issues can also be verified through FEA.

Introduction

As ball grid array (BGA) package sizes continually decrease, PCB failures due to over-flexure during various assembly and test processes have been an increasing concern in the electronics industry. Board flexure control using strain gauge testing has been proven to be an effective method in analyzing different assembly processes. Strain gauges are devices whose resistance changes under the application of force or strain. In a heat sink assembly process, an automated fixture is ideal but may not always be readily available. As such, production lines have utilized operators to do the manual work. Strain gauge measurements were done to evaluate both manual and automated assembly.

An FEA assembly model was generated to assess the strain and compare with experimental data. Several iterations were made and adjusted with the goal of optimizing the FEA model. The model was used in evaluating board strain at different conditions, such as moving the BGAs at another location.

Read The Full Article Here

Editor's Note: This article originally appeared in the September 2015 issue of SMT Magazine.

Share

Print


Suggested Items

SMTA Europe Solder Finish Webinar Addresses Defects Causes and Cures

12/14/2020 | Pete Starkey, I-Connect007
“What is your most common PCB problem?” A survey conducted by Bob Willis had revealed finish solderability to be the predominant contender, and it was clear that the choice of solderable finish applied to surface mount boards could have a significant effect on the assembly yield and cost of the final circuit. SMTA Europe organised an informative and enlightening webinar this month entitled “Guide to PCB Solder Finishes—Process Defects Causes and Cures,” with soldering specialist Bob Willis as presenter.

SMTA Europe Webinar: What Is a Good Solder Joint, and How Can Solder Joints Be Tested?

11/18/2020 | Pete Starkey, I-Connect007
What is a good solder joint? And how can they be tested not only for purposes of process characterisation, optimisation, monitoring, and control but also for ensuring their long-term reliability? Pete Starkey details a webinar organised by the Europe Chapter of SMTA that was presented by Bob Willis, an expert in soldering, assembly technologies, and failure analysis.

This Month in SMT007 Magazine: Robustness Is Not the Same as Reliability

09/02/2020 | I-Connect007 Editorial Team
Bob Neves discusses a disconnect he sees in reliability testing between what’s being tested and what happens out in the field, as well as why most reliability tests these days should instead be considered robustness tests.



Copyright © 2021 I-Connect007. All rights reserved.