Moisture absorption and desorption predictions for plastic ball grid array packages

Abstract

Abstract-Plastic electronic packages are known to absorb moisture when exposed to humid ambient conditions during storage in tape and reel in the factory. Reliability becomes a concern when packages are exposed to a humid environment for a prolonged time and then processed through a reflow oven. Thermo-mechanical and moisture induced interfacial stresses generated between the die attach and die may lead to die delamination and package cracking. Current package level moisture evaluation methods are based on experimental weight gain measurements and visual inspection after reflow for cracking or delamination. This study presents a finite element analysis (

Three-dimensional multi-layer through-hole filling properties of solderable polymer composites with low-melting-point alloy fillers

“…Such voids within the entrapped polymer composite could cause reliability issues such as LMPA-filled through-hole fracture and degradation of the mechanical properties of the interlayer interconnection, because of the decreased effective filling area and increased stress concentration [17,18]. When the multi-layer through-hole filling assemblies are exposed to high temperature conditions, the high stresses can be concentrated onto the polymer composite and LMPA-filled through-hole from the rapid expansion of voids within the polymer composite (like the popcorn cracking) [19][20][21]. As a result, voids within the throughhole may be involved in potential reliability problems with multi-layer through-hole filling assemblies.…”

Analytical solutions of gas transport problems in inorganic/organic hybrid structures for gas barrier applications

“…The heat conduction analogy is extremely useful in practice; ͑1͒ the analytical solutions of various heat conduction problems exist, 12 and ͑2͒ the majority of commercial software packages does not offer mass diffusion modules but only heat conduction modules. 13 The analogy has been utilized extensively to address water diffusion inside semiconductor packages [13][14][15][16][17][18][19] and food. 20 It is extended in this study to derive the analytical solutions of gas diffusion problems in inorganic/organic hybrid structures.…”

A convection–diffusion porous media model for moisture transport in polymer composites: Model development and validation

“…More significantly, it has been reported that absorbed moisture can cause the so‐called popcorn failures to polymer structures in high‐temperature environments . Due to phase changes in moisture at temperatures above 100 °C, massive water vapor can be produced in a very short time.…”

“…23,24 More significantly, 25 it has been reported that absorbed moisture can cause the so-called popcorn failures to polymer structures in high-temperature environments. 14,[26][27][28][29][30] Due to phase changes in moisture at temperatures above 100 8C, massive water vapor can be produced in a very short time. Vapor pressure can rise exponentially with temperature, eventually reaching a critical point and causing destructive damages.…”