Electronics Forum | Tue Feb 19 11:34:04 EST 2002 | AndyC
Do you mean middle height slice ? . This is a term used to describe the x-ray taken at a mid-ball position on a BGA ball , ie , the "fattest/widest" part if the ball . This is generally done to see if voids contained within have led to fracture acros
Electronics Forum | Tue Nov 10 07:35:04 EST 2009 | scottp
Step 1 is to find out what kind of opens you're getting through a cross-section or die & pry. Are they head in pillow, brittle fracture at the intermetallic, bulk solder cracks, ball separation from interposer? Without some basic failure analysis a
Industry News | 2021-08-30 21:24:05.0
In the refrigeration system of the cold storage, the refrigeration compressor is the core equipment. At present, piston refrigeration compressors are mostly used in small and medium-sized cold storage refrigeration systems. Because of the different refrigerating mediums, the compressors are often divided into ammonia type and fluorine type. This article will introduce to you common faults and ideas of piston ammonia refrigeration compressor
Technical Library | 2016-10-20 18:13:34.0
Pad cratering failure has emerged due to the transition from traditional SnPb to SnAgCu alloys in soldering of printed circuit assemblies. Pb-free-compatible laminate materials in the printed circuit board tend to fracture under ball grid array pads when subjected to high strain mechanical loads. In this study, two Pb-free-compatible laminates were tested, plus one dicycure non-Pb-free-compatible as control. One set of these samples were as-received and another was subjected to five reflows. It is assumed that mechanical properties of different materials have an influence on the susceptibility of laminates to fracture. However, the pad cratering phenomenon occurs at the layer of resin between the exterior copper and the first glass in the weave. Bulk mechanical properties have not been a good indicator of pad crater susceptibility. In this study, mechanical characterization of hardness and Young’s modulus was carried out in the critical area where pad cratering occurs using nano-indentation at the surface and in a cross-section. The measurements show higher modulus and hardness in the Pb-free compatible laminates than in the dicy-cured laminate. Few changes are seen after reflow – which is known to have an effect -- indicating that these properties do not provide a complete prediction. Measurements of the copper pad showed significant material property changes after reflow.
Technical Library | 2015-02-12 16:57:56.0
Electronic systems are known to be affected by the environmental and mechanical conditions, such as humidity, temperature, thermal shocks and vibration. These adverse environmental operating conditions, with time, could degrade the mechanical efficiency of the system and might lead to catastrophic failures.The aim of this study is to investigate the mechanical integrity of lead-free ball grid array (BGA) solder joints subjected to isothermal ageing at 150°C for up to 1000 hours. Upon ageing at 150°C the Sn-3.5Ag solder alloy initially age-softened for up to 200 hours. This behaviour was linked to the coarsening of grains. When aged beyond 200 hours the shear strength was found to increase up to 400 hours. This age-hardening was correlated with precipitation of hard Ag3Sn particles in Sn matrix. Further ageing resulted in gradual decrease in shear strength. This can be explained as the combined effect of precipitation coarsening and growth of intermetallic layer. The fractured surfaces of the broken solder balls were also investigated under a Scanning Electron Microscope. The shear failures were generally due to ductile fractures in bulk solders irrespective of the ageing time.
SMTnet Express, January 27, 2022, Subscribers: 25,985, Companies: 11,506, Users: 27,032 Fracture Toughness Analysis of Epoxy-Recycled Rubber-Based Composite Reinforced with Graphene Nanoplatelets for Structural Applications
Imagineering, Inc. | https://www.pcbnet.com/blog/everything-you-need-to-know-about-moisture-sensitive-devices-msds/
. Surface-mount boards tend to be thinner, thus having lower fracture strength. Ball grid arrays are the most frequent culprit, as moisture can lead to component warpage in addition to the other types of damage