Showing 18 records.
SEM-EVIDENCE-0001
This paper covers BGA assembly verification using microsection and SEM analysis. The source page makes the practical purpose clear: the work is used to optimize assembly processes early in the product development cycle and help prevent failure during production. That makes this paper more than a narrow inspection note. It is a process-validation reference for engineers who need to verify that BGA assembly quality is adequate before product release or volume manufacturing.
solder-joint quality defects
SEM-EVIDENCE-0002
This paper covers the use of diffusion barriers in electronics manufacturing and the practical reasons they matter. The source page notes that diffusion barriers have been used for decades, but that SEM Lab still sees cases where barrier layers are omitted when they likely should have been used. The page positions the paper as a series of examples illustrating diffusion-barrier use in electronics manufacturing and links the issue directly to soldering-process quality and solder-joint reliability. That makes the paper useful both as a microstructural reference and as a process-selection reference.
barrier-layer omissioninterfacial degradation
SEM-EVIDENCE-0003
This paper is described on the source page as a 21-page booklet summarizing the author's experience performing failure analysis on aluminum electrolytic capacitors over a fifteen-year period. It covers failure mechanisms seen in these capacitors and the failure-analysis techniques used to identify the failures. The source page also notes that the document includes figures, equations, and graphs. That makes it a deeper stand-alone technical reference rather than a short overview paper.
capacitor failure
SEM-EVIDENCE-0004
This paper covers practical approaches for failure analysis of Ball Grid Array devices. The source page describes BGA analysis as difficult because of the high I/O count and packaging density, and it positions the paper as a discussion of several BGA failure modes and analysis approaches that can be performed with a limited number of analytical tools. The paper also appears to distinguish between cases that can be addressed with limited tools such as a DMM, microsectioning, and SEM/EDS, and cases where more advanced work is needed to identify the failure cause.
BGA open circuitBGA short circuitsolder-joint fracture
SEM-EVIDENCE-0005
This paper covers recurring LED failure modes and the practical failure-analysis approach used to evaluate them. The source page describes intermittent or no-light symptoms, and it notes that LED failures often involve de-bonding of the lens material from the cup or die surface due to thermal-expansion mismatch and thermal stress. The paper also appears to summarize other failure modes seen in SEM Lab LED work, including die attach failure, die cracking, wedge bond failure, and ball bond failure. The overall pattern is that many of these failures are induced by mechanical or thermo-mechanical stresses.
die crackingdie-attach failurewire-bond failure
SEM-EVIDENCE-0006
This paper covers practical failure-analysis approaches for printed circuit board assemblies. The source page outlines a general workflow that includes documentation review, microscope examination, electrical isolation or verification of the failure, cross-sectioning for PWB-related failures, decapsulation or cross-sectioning for component-related failures, and SEM/EDS work to document the failure site and resolve root cause. The page also includes practical "dos and don'ts" intended to improve the timeliness and cost effectiveness of PCBA failure analysis. That makes the paper useful not only as a mechanism reference, but also as a guide to handling, documentation, and pre-analysis discipline.
contaminationcorrosionassembly failure
SEM-EVIDENCE-0007
This paper covers common failure modes in PWBs and connects those failures back to board construction quality. The source page specifically identifies Hi-Pot failures, lamination failures, inner layer separation, corrosion failures, PTH copper-plating failures, and conductive anodic filament failures as part of the paper's scope. It also makes a practical point that construction analysis can be used to verify PWB quality before these issues become larger reliability or failure problems. That makes this paper useful both for failure analysis and for front-end quality verification.
conductive anodic filament formationlamination failureinner-layer separation
SEM-EVIDENCE-0009
This paper examines ten anonymized semiconductor and optoelectronic failure-analysis cases and organizes their electrical behavior into practical forward-voltage signature classes. It distinguishes near-zero voltage, open or elevated voltage, current-dependent elevation, depressed voltage, and nominal voltage with degraded function. The central engineering lesson is that forward voltage is a strong triage and localization measurement, but not a stand-alone root-cause determination. Controlled current and temperature, matched references, functional observations, and targeted physical analysis are needed to support a defensible conclusion.
open circuitshort circuitelectrical degradation
SEM-EVIDENCE-0010
This paper covers FTIR analysis as a materials-analysis technique. The source page describes FTIR as providing spectral information that acts as a molecular fingerprint for organic, polymeric, and in some cases inorganic materials. The page specifically notes its value for identifying base polymer compositions and organic contaminants by comparing unknown spectra against reference libraries. That makes the paper useful both as a basic technique reference and as a practical contamination-analysis reference.
organic contaminationmaterial mismatch
SEM-EVIDENCE-0011
This paper covers gold embrittlement of solder joints as a recurring and still significant electronics failure-analysis problem. The source page notes that gold-embrittlement-related failures represent a significant portion of the work analyzed at SEM Lab and states that the paper provides a detailed account of material and process parameters that can lead to this condition in electronic assemblies. The paper appears to be positioned both as a practical failure-analysis reference and as a prevention-oriented document for understanding how solder-joint design and process choices can avoid embrittlement problems.
gold embrittlementbrittle solder-joint fracture
SEM-EVIDENCE-0012
This paper covers HASL finish on PWBs and fits the practical process side of the SEM Lab paper catalog. It belongs with the papers that help engineers evaluate assembly-related materials and process conditions before those conditions turn into field or manufacturing failures. The paper should be positioned as a useful reference for engineers dealing with solderability, surface-finish quality, and the effect of board finish condition on assembly results and longer-term reliability.
solderability degradationsurface-finish defects
SEM-EVIDENCE-0013
This paper is positioned as a collection of failures seen at SEM Lab in microelectronics packaging. The source page states that it includes examples such as gold embrittlement, mechanical damage, solder-joint failure, black pad syndrome, and various other failure mechanisms. That makes the paper useful as a broad visual and mechanism-oriented reference rather than a narrowly focused single-topic treatment. It appears to function as a consolidated packaging-failure example set.
gold embrittlementmechanical damageblack pad
SEM-EVIDENCE-0014
This paper explains why intermetallic compounds in solder joints are not a simple "good" or "bad" issue. It covers the basic role of intermetallic layers, why excessive intermetallic formation can damage joint performance, and why the absence of expected interfacial intermetallics can indicate a process or material problem. The paper discusses several intermetallic systems that are important in electronics work, including Cu6Sn5, Cu3Sn, Ni3Sn4, AuSn4, and Ag3Sn. It also includes discussion of gold embrittlement, volume-fraction effects, and ternary intermetallic phases that can contribute to brittle interfacial behavior.
excessive intermetallic growthbrittle interfacial fracture
SEM-EVIDENCE-0015
This paper converts selected SEM Lab MLCC bending and flexure fracture case records into a stand-alone paid technical paper. It focuses on how to interpret MLCC ceramic cracks as electrical failure evidence, especially when fractures intersect active capacitor plates, bridge opposite-polarity electrodes, or coincide with short sites. The paper keeps case identifiers for traceability and separates direct bending/flexure evidence from supporting cases, inferred comparisons, and a no-fracture control case.
MLCC flex crackingbending fractureelectrical leakage
SEM-EVIDENCE-0016
This paper covers solder flux residue left on printed circuit board assemblies and the problems it can cause, including corrosion, electro-chemical migration, electrical leakage, and short-circuit faults. The source page also makes clear that the paper investigates what conclusions can be drawn from EDS data for solder flux residue. That gives the paper practical value beyond simple contamination awareness. It helps connect residue, analytical evidence, and engineering interpretation in cases where the contamination mechanism matters.
corrosionelectrochemical migrationelectrical leakage
SEM-EVIDENCE-0017
This paper extends the solder-flux-residue topic by examining how to interpret EDS data when the electron beam can penetrate thin residue layers and include contribution from the solder mask underneath. The source page specifically frames the paper around removing that solder-mask contribution from the analysis. That makes Part 2 a useful companion to Part 1 rather than a repeat. It is focused more narrowly on how to interpret the data correctly when residue is present on a PCBA surface.
contaminationanalytical interference
SEM-EVIDENCE-0018
This paper covers techniques for analyzing solder joints and highlights SEM Lab capabilities in solder-joint evaluation and failure analysis. The source page specifically identifies metallurgical cross-sectioning, SEM/EDS analysis, failure analysis, and computational metallurgical analysis as part of the paper's scope. The page also states that the analysis results are essential for credible design, process, and product failure analysis. That positions the paper as a broad solder-joint reference rather than a narrow mechanism note.
solder-joint failuremetallurgical defects
SEM-EVIDENCE-0019
This free 10-page sample report demonstrates how SEM Lab connects electrical behavior, failure-site location, SEM imaging, EDS chemistry, process history, and evidence limits in a clear technical deliverable. Six anonymized cases show how retained solder-flux residue can contribute to moisture-sensitive leakage, corrosion, electrochemical migration, and combined manufacturing defects. The report also provides a failure-analysis sequence and practical process controls. It is published as a composite marketing example so prospective clients can evaluate the structure, evidence traceability, and calibrated conclusion language used in SEM Lab technical reporting.
moisture-sensitive leakagecorrosionelectrochemical migration