Finite element modeling of electronic packages subjected to drop impact

Abstract

As more electronic products become portable, many product manufacturers have started to pay more attention to the robustness of their products. Finite element (FE) simulation has become increasingly popular in the analysis of products subjected to impact loading. The need for details in a FE mesh is always balanced by considerations of simulation time and available computational resources. In this paper, three commonly used approaches to FE modeling of a ball grid array (BGA) package subjected to drop impact are evaluated. The first model comprises a detailed mesh of the printed circuit board (PCB), integrated circuit (IC) package and interconnecting solder balls using solid three-dimensional (3-D) elements. The degrees of freedom is reduced for the second mesh by using shell elements for the PCB and IC package while retaining the detailed mesh of the solder balls using solid 3-D elements. The third mesh is a further simplification of the second mesh whereby the solder balls are replaced by a single beam element each. The stresses within the solder balls are then obtained in a separate FE analysis of a detailed solder ball mesh using the displacement history of nodes around the beam elements from the previous analysis as inputs. Solder ball stresses from all three meshes were found to differ by as much as 40% although PCB deflection compared favorably.Index Terms-Ball grid array (BGA), drop impact, finite element (FE) simulation.

Effects of different drop test conditions on board-level reliability of chip-scale packages

“…In order to understand structural responses and failure mechanisms of the board-level test vehicle subjected to JEDEC or other pulse-controlled drop test methodologies alike, numerous theoretical (e.g., [5][6][7][8]), experimental (e.g., [9][10][11][12][13]), and numerical studies (e.g., [13][14][15][16][17][18][19][20]) have been conducted. Most of these studies focused on a single test condition only.…”

Endurance of lead-free assembly under board level drop test and thermal cycling

“…The reliability under the transient mechanical impact by the accidental drops becomes concerned as well as the reliability under the thermo-mechanical stresses. Recent years the reliability of assemblies under drop test were studied by some investigators with experimental works and numerical simulation analyses [12][13][14][15][16][17]. However, most of these investigations focused on the mechanical responses (acceleration, strain, etc.)…”

Board level drop test and simulation of leaded and lead-free BGA-PCB assembly

“…For the handheld electronic products, because they are more prone to be dropped, the reliability under drop-induced stress is critical for the BGA-printed circuit board (PCB) assemblies. Some research teams, respectively, analyzed the board level reliability of BGA-PCB assembly under the influence of different drop direction, different component structure and position, different package type, different solder, paste, underfill material, different surface finishing, different PCB size, shape, structure and material, and other parameter changes, presented some useful and reasonable conclusions [5][6][7][8][9][10][11][12]. Papers published which focused on this area, however, are still limited.…”