Evidence previews
Each preview establishes relevance and method. Members and purchasers receive the complete evidence sequence, interpretation, alternatives, and limitations.
Case 2301 preview
Failed contacts contained a carbon-, oxygen-, and cadmium-rich surface product. The combined electrical, imaging, and chemical evidence supported accumulation of a nonconductive reaction product on Ag-CdO contacts rather than mechanical binding.
Case 2295 preview
The fracture evidence and construction comparison supported excessive power relative to the component's thermal capability, aggravated by a relatively poor heat-conduction path through ferrous leads and by heat-retaining staking material.
Case 2108 preview
Complementary fracture surfaces showed fatigue progression followed by final ductile shear. Surface, microstructure, and composition comparisons did not reveal a material-quality difference that explained the failures.
Case 2556 preview
X-ray and microsection evidence showed voids and fractures in both the heat-transfer adhesive and resistor enamel. These features increased thermal impedance and reduced design margin, but they were present in both passing and failing assemblies.
Case 2339 preview
Microsections showed encapsulant separating from the ceramic/thick-film substrate and lifting gold stitch bonds with it. A second mounting method and decapsulation evidence supported the same failure sequence.
Case 1861 preview
Electrical and construction comparisons linked the overheated condition to winding conductors that were substantially larger than those in a comparison design. The lower winding resistance was consistent with increased current and loss of thermal margin; dielectric breakdown between windings was not observed.
Case 2234 preview
The devices showed two credible contributors: mechanical damage at gate leads and associated wire bonds, and ionic residue containing calcium, sulfur, and phosphorus near device surfaces. No die-level electrical-overstress damage was identified.
Case 1695 preview
Lens fractures originating near metal posts created paths for moisture and ionic contamination. Corrosion and contamination within cracks could shunt the electrodes and suppress light output. No EOS or ESD damage was found on the examined die.
Case 2181 preview
Chloride in the electrolyte and corrosion product supported a cyclic aluminum-dissolution mechanism that generated hydrogen, increased leakage, and promoted bulging. Depolarizer depletion or low concentration may have aggravated the condition.
Case 2213 preview
Moisture-assisted reactivation of previously isolated dielectric defects was a plausible contributor, while underside corrosion residue, voltage margin, mechanical damage, and MnO2-layer variability represented additional risks. No single feature explained every failed unit.
Case 2015 preview
The evidence did not support internal or termination cracking as the cause of leakage. Electrical behavior and construction analysis were more consistent with premature degradation of X5R base-metal-electrode dielectric associated with material and fabrication details.
Case 2214 preview
Chloride-bearing residue, tin-oxide corrosion product, moisture, and electric field supported an electrochemical-migration short between power and ground beneath a connector. The resulting high-current event fused or vaporized pads, plated holes, and internal copper.
Case 1775 preview
A hemispherical primary breakdown site originated near the MnO2 and tantalum-slug interface, a morphology consistent with surge-current heating. Operating voltage above recommended derating likely increased susceptibility; no general fabrication defect explained the failure.
Case 2031 preview
Residual activated flux and incompletely rinsed detergent left chloride and surfactant material beneath connector bodies. Moisture converted these residues into conductive leakage paths and promoted corrosion of copper, solder, and connector metals.
Case 2712 preview
Microsections of three suspect capacitors contained no internal electrode plates. The most plausible manufacturing scenario was an electrode-free region of ceramic tape proceeding through singulation and termination, followed by inadequate final electrical screening.
Case 1774 preview
Tin-lead corrosion products containing significant chloride nearly bridged the space between capacitor terminals. Large voids in the mounting adhesive trapped activated flux and provided sheltered paths for corrosion and electromigration; no ceramic fracture or internal construction anomaly explained the behavior.
Case 873 preview
Elevated-temperature exposure produced post-cure shrinkage cracks and separation of the epoxy lens from the die and ceramic cup. Marginal adhesion allowed damage to progress from optical clouding to extensive fracture and complete lens loss, while steam exposure likely aggravated moisture ingress.
Case 2453 preview
Lens material debonded from the bottom of the LED cup, most likely during wave-solder thermal overstress. Potting voids and a nearby resistor reduced thermal margin; subsequent heating produced encapsulant fractures around the bond wire and apparent wire discontinuities that accelerated wear-out.
Case 1654 preview
Primary flexure fractures in both failed capacitors coincided with their electrical short sites. The fracture geometry supported PCBA bending stress, followed by electrical breakdown and extensive secondary cracking; comparison devices did not support defective capacitor manufacture as the primary cause.
Case 2383 preview
The joints failed by brittle interfacial fracture at the nickel-phosphorus/nickel-tin intermetallic interface under impulse bending or tensile overload. Excessive gold content, gold-tin intermetallic plates, and trapped flux and gas reduced process margin but were secondary to mechanical loading.
Case 2103 preview
Failures initiated at predictable high-stress features while extensive gas porosity reduced the effective load-bearing area. Possible alloy variation and loading at the trailing end were additional contributors, linking both casting quality and application stress to the failures.
Case 1989 preview
Corner joints fractured between nickel-tin intermetallic and electroless nickel. Irregular nickel plating, low bulk phosphorus in one assembly, excessive intermetallic thickness, mechanical or thermal-mechanical corner stress, and under-BGA residue formed a multifactor failure condition.
Case 1290 preview
The capacitor shorted and drew sufficient current to fuse its silver electrodes and dielectric, destroying most evidence of the initiating defect. An intact comparison capacitor showed no manufacturing anomaly, leaving adhesive stress and rapid low-temperature surge heating as plausible but unproven hypotheses.
Case 1426 preview
Brittle fractures occurred at both package-side and board-side ball interfaces. A single soldering, board-finish, or package-fabrication defect was unlikely to weaken both unrelated interfaces, making mechanical shock or PCBA bending the best-supported common cause.
Case 2074 preview
Increasing capacitance, elevated dissipation factor and leakage, aluminum in the electrolyte, acidic conditions, and insufficient phosphate supported dissolution and thinning of the aluminum-oxide dielectric. Rated-voltage conditioning partially restored electrical behavior by reforming dielectric.
Case 102 preview
The bottom surfaces of nonwetted leads lacked their tin-lead finish and exposed copper-tin intermetallic, whose oxide is difficult to wet. Organic material incorporated during electroplating likely weakened the finish-to-base-metal interface and allowed separation or dewetting during thermal or mechanical stress.
Case 1588 preview
Excessive internal pressure and dried electrolyte caused severe loss of capacitance. Thermally discolored sleeves and staking material supported high-temperature exposure, consistent with excessive ripple current, rapid charge-discharge cycling, or reverse bias generating internal heat and gas.
Case 2466 preview
Tin-lead particles trapped beneath the outer coating bridged adjacent laser-trimmed resistor tracks and caused low-resistance failures. Narrower-than-required laser cuts increased bridging susceptibility, while thermal shock from a temporary particle short plausibly fractured resistor material and produced high-resistance cases.
Case 2437 preview
The strongest correlation with suspect transformers was conductor spacing below the expected two-insulation-thickness margin. Excessive winding tension likely compressed or strained the insulation, with reflow thermal expansion adding stress; variable tape and winding counts documented broader process inconsistency.
Case 1889 preview
Localized electrical arcs damaged the contact surfaces, while extensive nickel-tin, copper-tin, and zinc-tin intermetallic growth consumed much of the metallic tin. Permanent deformation reduced contact force. Hot mating or excessive operating current better explained the combined damage than a single isolated plating flaw.
Case 2272 preview
Internal corrosion opened the anode leads just inside the rubber seals. Poor seal condition and lead-construction features plausibly allowed moisture and contamination to enter; the not-yet-failed capacitors showed the same corrosion mechanism at an earlier stage.
Case 1040 preview
No EOS or ESD damage was found. Metallic debris, passivation damage, and large die-attach voids were credible contributors, but destructive die removal prevented a unique causal assignment.
Case 1701 preview
Sulfur corroded the silver-plated lead frames in the exposed LED cavities and produced open circuits. Silver protected within the molded body remained intact, while FTIR identified the clear lens as silicone, a material that did not provide an effective sulfur diffusion barrier.
Case 1755 preview
The capacitors experienced premature wear-out consistent with excessive operating temperature. Complete electrolyte dry-out reduced capacitance, raised dissipation and ESR, and generated enough internal gas pressure to bulge the cans.
Case 1824 preview
Excessive die-attach voiding increased thermal impedance, elevated junction temperature, and most likely drove thermal runaway followed by internal shorting. Similar voids in functional controls showed that the defect was systemic and could precede catastrophic failure.
Case 2386 preview
Both LEDs opened because their gold bond wires fractured immediately above the silicone encapsulant interface. Thermal-property mismatch concentrated stress at that transition, while gas voids in the silicone likely increased local strain.
Case 123 preview
Delamination occurred between an internal copper plane and B-stage laminate because the copper surface lacked an effective adhesion-promoting oxide treatment. Bromine enrichment at the opposing laminate surface may have further reduced bond strength.
Case 1266 preview
A localized fused region of tantalum and tantalum oxide identified dielectric breakdown within the slug. The evidence favored transient overvoltage followed by excessive current damage, with no repeated fabrication defect or polymer-cathode anomaly.
Case 1764 preview
The most consistent failure mechanism was unstable conduction through silver-epoxy beneath the green dice. Silver-poor regions reduced particle contact, and slight sectioning displacement restored conduction, supporting progressive die-attach wear-out.
Case 1770 preview
Crevice corrosion attacked nickel-phosphorus coating on the rods and stainless steel inside the fitting. Nonuniform protective coating, oxygen-depleted geometry, and uncontrolled dissolved water species created a credible coupled corrosion environment.
Case 1793 preview
The springs failed by vibration-fatigue crack growth at the highest-stress weld-adjacent location, followed by ductile rupture of the remaining section. The repeated geometry indicated loads or displacement beyond the design capability rather than a material or welding defect.
Case 1680 preview
The examined lot showed the lowest black-pad risk among the compared populations. Sections contained no solder-joint fractures or phosphorus-rich interfacial layer, and fracture surfaces lacked nickel grain-boundary hyper-corrosion.
Case 2037 preview
The shorts were most consistent with conductive anodic filament formation through glass-fiber paths debonded from the resin. Resin recession, pad lifting, and solder anomalies indicated thermal overstress that damaged the PTH-region laminate and increased CAF susceptibility.
Case 2168 preview
The degraded capacitor contained a ceramic flexure crack beneath one termination. Its location and trajectory indicated board bending, and the crack reduced capacitance by electrically isolating part of the internal electrode stack.
Case 2127 preview
Operation at 150 percent of rated forward current produced accumulated thermal-mechanical damage. Repeated evidence included decomposition around the hottest wire span, ductile gold-wire rupture, encapsulant fracture, and separation from the cup.
Case 1636 preview
The capacitors did not share one failure mechanism. One failed through board-flexure cracks associated with breakout stress; two others most likely leaked through as-fabricated porosity that shortened migration paths between opposing nickel electrodes.
Case 1585 preview
Localized corrosion severed the anode lead or foil connection near the seal. Gas generation and vent or seal damage indicated electrical or thermal stress; ripple current, charge-discharge rate, or operating temperature were the leading contributors.
Case 1237 preview
Cracks most likely preceded the final event. They created multiple paths for silver migration and localized breakdown rather than the single fused origin expected from primary EOS. Reflow, board flexure, later thermal testing, or a combination could have produced them.
Case 958 preview
Zinc was present, but the plating issue did not significantly increase total particle load. Much of the zinc was consistent with assembly debris, alongside numerous non-zinc particles.
Case 1462 preview
The heater fractured near the end of its copper sleeve. Sleeve nonconcentricity, degradation, and apparent silver diffusion could produce thermal stress, while the bent tip and a separate inboard crack also supported mechanical bending.
Case 1465 preview
Physical examination did not reveal the cause of the electrical degradation. Bond wires, pads, and die surfaces appeared normal, with no visible corrosion, EOS, or ESD site. Subtle junction contamination, an invisible parametric ESD defect, or lead damage remained possible.
Case 2311 preview
Chlorine and sulfur contamination within the PWB structure was the most likely cause of internal electrical breakdown. Similar contamination in an unused board, including at an internal layer and between PTH copper and the drilled-hole wall, indicated exposure before final board fabrication.
Case 882 preview
The likely joints failed through excessive flux-filled voids at the BGA ball interface. The voids removed more than half of the load-bearing area in some joints. Barium in trapped flux suggested a possible flux and solder-mask incompatibility. Minor black-pad evidence was a secondary concern.
Case 2322 preview
Sulfur in the seal, titanium on the silicone coating, and trace chloride were not connected to a functional fault. No gross component or EOS damage was found, so electrical fault isolation was still required.
Case 1796 preview
Steam exposure drove extensive zinc and tin corrosion and ionic leakage. Zinc-plated hardware likely accelerated nearby tin corrosion through galvanic effects, while incomplete conformal-coating coverage exposed adjacent conductors. The steam environment remained the dominant cause.
Case 371 preview
A short between the primary and bifilar secondary windings placed line voltage onto a lower-voltage circuit, causing downstream capacitor and resistor failures. A single thin insulation-tape layer and large voids at the winding interface were plausible construction contributors.
Case 897 preview
The joints failed because Au-Sn intermetallic platelets segregated at interfaces and void surfaces, creating local gold concentrations above the embrittlement threshold. The platelets also may have obstructed volatile escape during reflow and contributed to severe voiding.
Case 670 preview
The failures were caused by overheating through localized hot-spot formation or generalized junction diffusion. Die-attach voids could impede cooling or concentrate current, but voiding did not correlate strongly with failure because a functional comparison device contained extensive porosity.
Case 1179 preview
Wear of soft Ag-Ni wipers deposited conductive particles in dielectric gaps between gold pads. Mixed with contact lubricant, the particles formed a paste capable of unstable electrical leakage. Hard glass fibers, tarnish, load variation, and alloy composition could accelerate wear.
Case 339 preview
Comparative EDS found no significant carbon-to-copper or oxygen-to-copper difference among the board groups. The solder-joint failures therefore were unlikely to have resulted from organic contamination in the electroplated copper. Silicon differences were not linked to failure.
Case 2457 preview
Thermal overstress and fatigue damaged the source and gate aluminum bond wires. An intermittent gate connection could leave charge on the gate capacitance and hold the MOSFET on, creating the appearance of a source-drain short even though its body diode was not shorted.
Case 206 preview
Fracture of the package lens produced a gross hermeticity breach, while cracked lead seals created an additional leakage path. Moisture ingress and associated electrical leakage provided a credible explanation for unstable laser power.
Case 515 preview
Chloride-bearing flux residue promoted electrochemical migration of tin and lead compounds between oppositely biased connector lands. The resulting conductive path supported leakage and eventually arc-over, producing severe secondary thermal damage.
Case 2369 preview
Board bending fractured resistor terminations, often beneath the nickel barrier within the silver thick-film layer. A nearby cutout reduced local stiffness and plausibly concentrated strain at the components.
Case 140 preview
The LED wire failed in shear at the heel of the wedge bond on the post. Thermal contraction after reflow, acting through a structure with limited thermal stability, was the most credible source of mechanical stress.
Case 2312 preview
The new probes had rougher internal surfaces than older probes, and process residues were retained within their mechanical imperfections. This supported a connection between inadequate internal finish, cross-contamination, and signal instability.
Case 2314 preview
During reflow, solder consumed the Ag-Pd termination and formed a Sn-Pb-Ag-Pd layer. Its weak interface with the ceramic created an incipient flaw that required little additional stress to propagate.
Case 99 preview
Intergranular stress-corrosion cracks initiated at outside edges, grew slowly through a limited portion of the section, and were followed by rapid ductile fracture of the remaining ligament. Ionic surface deposits and possible galvanic interaction were credible corrosion contributors.
Case 1343 preview
Loose case-material particles at the contact interface were the most plausible intermittent mechanism. Copper oxide remained credible but would more likely produce persistent resistance.
Case 1537 preview
Excessive current draw overheated the solenoid windings. Wire insulation burned away, potting decomposed, and copper surfaces approached melting temperature. The damage did not originate from circuit-board insulation breakdown.
Case 2020 preview
The recalled assemblies contained more severe flux residue and corrosion around the FET leads than a working comparison. Chloride-bearing, tin-rich corrosion product extended between adjacent leads and created a credible path for electrical leakage and eventual hard failure.
Case 287 preview
Moisture and ionic contamination could enter through capillary gaps at the lead-to-body interface and reach molding defects beside the die. Copper dendritic growth along that internal interface provided a conductive path between the diode terminals.
Case 1475 preview
The tube interior was dominated by severe rusting rather than a detectable fatigue crack. Gas-pocket and vent-like morphology, together with localized sulfur, made microbiologically influenced corrosion a credible possibility, although it was not proven.
Case 999 preview
High-cycle vibration fatigue initiated in the heel fillets and propagated toward the toes through eutectic Sn-Pb solder near the Cu-Sn intermetallic interface. Component mass, excessive vibration loading, or both produced the damaging stress.
Case 1410 preview
Thermal runaway or overcurrent created a large melt pipe in each failed die and alloyed silver from the contact with silicon. Off-center die mounting and fractured glass cases could have reduced heat-transfer margin and aggravated the failures.
Case 772 preview
Inner-layer copper separated from electroless copper in plated-through component holes. As-fabricated comparisons already contained partial weakness, while soldering heat and drill breakout aggravated the failed connections.
Case 892 preview
Wear transferred silver conductive ink and binder from the mating dome onto the ENIG pattern. Oxidation and raised deposits could increase contact resistance, but the examined ENIG finish did not show the grain-boundary hypercorrosion associated with black-pad defects.
Case 1944 preview
The examined BGA solder joints were intact. More credible mechanical evidence appeared within the packages: one die was fractured, while another device had deformed pads and local separation at a pad-to-molding-compound interface.
Case 1320 preview
Pre-existing termination fractures intersected the internal electrode stack. Electrical breakdown followed the cracks between capacitor plates, melted local ceramic and metallization, and produced permanent shorts.
Case 1791 preview
Sodium chloride attacked worn contact regions where gold was removed and nickel or base metal was exposed. Corrosion then traveled beneath the plating and deeply into the connector metal.
Case 2121 preview
Sulfur attacked the silver thick-film conductor where the termination barrier met the resistor cover glass. Silver sulfide replaced the conductor, disrupted adhesion, lifted the termination locally, and opened all three resistors.
Case 2157 preview
Electrical overstress produced breakdown near the outside of the tantalum slug, consistent with surge-current damage. The design operated the capacitor at 63% to 100% of rated voltage rather than the 50% derating cited in the report, leaving inadequate margin for reliable operation.
Case 2455 preview
One or both die ball bonds failed as the lens material delaminated from the die surface. The unusually spherical, minimally deformed bonds indicated under-bonding and weak mechanical support, making the interconnects vulnerable to thermomechanical stress.
Case 2444 preview
Excessive heating during heat-shrink processing remelted the failed solder joint and allowed most of its solder to flow away. The affected joint retained only about 13% of the average solder area of the other three joints, while the damaged assembly also showed evidence of greater copper dissolution into the solder.
Case 1334 preview
Corrosion removed the NiCr resistor pattern at its edge and created one or more opens. Misregistration of the glass cover, possible cover-firing issues, and micropores within the glass and resistor-film interface were plausible paths that left the thin film vulnerable.
Case 1858 preview
The output FET sections were electrically degraded, but physical examination revealed no definitive failure site. The behavior was consistent with low-energy EOS or ESD causing parametric damage below conventional SEM detection limits.
Case 188 preview
Sodium- and potassium-bearing alkaline residues on the gold surface promoted corrosion through microscopic pores and seams in the plating. The copper-alloy base metal oxidized, expanded, attacked the nickel underlayer, and lifted remaining gold from the contacts.
Case 736 preview
Damage and approximately 1-2 microns of separation at the die-to-die-attach interface increased series resistance and created a credible intermittent-open path. Thermal-expansion stress, physical stress during rapid decompression, or both displaced the dice from their mounting pads.
Case 1100 preview
Residual stress fractured the weld through its section of minimum thickness. The thin section acted as a hinge between the joined components even though fusion was sound and no porosity or other weld defect sufficient to explain failure was found.
Case 1220 preview
The evidence did not support an intrinsic capacitor failure. Chloride-bearing activated flux residue and tin-lead corrosion surrounded the component and other nearby conductors, creating credible external leakage or electrochemical-migration paths to an adjacent ground plane.
Case 2268 preview
Gold-bearing intermetallic exceeded customary embrittlement thresholds and occupied an estimated 14.5% of the bulk solder in one attachment. Fracture followed the copper-to-gold-copper-tin intermetallic interface, making excess gold a credible design-level embrittlement risk.
Case 1920 preview
The capacitor reached end of life after excessive internal heating and electrolyte loss. The evidence was consistent with excessive ripple current, excessive ambient temperature, or both accelerating ESR growth, core temperature, venting, and final capacitance loss.
Case 250 preview
Mechanical overload normal to the board fractured adhesive bonds and, at some locations, solder joints. The evidence did not support fatigue or contamination. Nonuniform adhesive application could have amplified local stress but did not fully explain damage across separate component groups.
Case 1806 preview
Thin, granular manganese-dioxide layers increased local resistance and encouraged hot-spot formation during surge current. Shorted devices developed extensive tantalum-manganese alloying, oxygen generation, and rupture or melting of the overlying silver layer.
Case 2537 preview
Internal bond wires were swept together and mechanically damaged near one die corner. Broken wires created direct open paths. Injury occurred after wire bonding but before molding; molding flow subsequently swept the wires.
Case 2548 preview
The evidence supported an electrical-overstress event involving the primary power transistor and possibly a nearby device. Missing gate features suggested that gate-source breakdown may have initiated a subsequent source-drain overcurrent condition.
Case 246 preview
The failures were most consistent with mechanical or thermomechanical overstress rather than a recent construction change. Dimensions and materials closely matched an earlier construction, and the original window glass-to-metal adhesion appeared sound.
Case 1441 preview
The modules most likely failed through either moisture-and-ionic-contamination ingress or electrical overstress. Potting recessed below the enclosure lip left the circuit-board edges exposed, creating a significant environmental and electrical-clearance vulnerability.
Case 296 preview
Residual chloride from assembly flux was the primary corrosion driver. Blistering at the nickel-to-copper interface provided rupture sites that exposed the copper base alloy, creating local sources for copper-rich corrosion products.
Case 1178 preview
Poor component-lead solderability created weak lead-to-solder interfaces. Contributing conditions included an unusually thin and nonuniform tin-lead finish, copper-tin intermetallic exposed at the surface, and substantial oxidation and chloride contamination.
Case 1219 preview
Conductive metallic marking on the resistor body most likely contributed a parallel leakage path. The subject resistor carried substantially more extraneous metal than the controls, although some marking on control parts showed that the transfer mechanism was systemic.
Case 1292 preview
Abnormal gas voids in the PWB laminate most likely enabled the isolation failure. The voided glass-fiber bundles crossed regions between electrical features and could trap moisture or processing chemistry, supporting ionic conduction or conductive-anodic-filament formation under humidity and bias.
Case 2026 preview
The ferrite beads failed through mechanical flexure associated with loading from an adjacent spring. Repetition at one board location, the local board geometry, and consistent fracture orientation supported a design-driven stress condition rather than a component or soldering defect.
Case 2153 preview
The short most likely originated from a solder shunt between a switching pin and the grounded thermal pad beneath a power device. Residual solder on the removed package provided physical witness to a bridge that could explain the board short and secondary heating.
Case 2639 preview
The failures were most consistent with electrochemical migration creating an ionic shunt across the die. Related alloy and residue conditions on unused devices indicated an as-fabricated susceptibility rather than application overheating alone.
Case 301 preview
The joints fractured primarily between bulk solder and the tin-nickel intermetallic layer at the board surface. Evidence supported a combination of post-reflow mechanical or thermal stress and an unusually weak interface, with inadequate reflow and pre-plating nickel contamination remaining plausible contributors.
Case 1270 preview
Thermal and mechanical damage displaced the lower-mass anode posts and fractured the wedge-bond wires near the heel, producing open circuits. Similar damage in the functional comparison indicated a progressive susceptibility rather than an isolated electrical defect.
Case 1340 preview
Localized corrosion removed aluminum from active die bond pads and exposed the underlying titanium-tungsten via structure. The resulting loss of pad continuity most likely produced the observed open or high-impedance signals.
Case 352 preview
Adjacent primary wires shorted in the first winding layer above the core after localized heating softened or decomposed their insulation. The resulting overcurrent fused wires together and open, producing extensive secondary thermal damage.
Case 1276 preview
The optical irregularity was associated with surface residues containing hydrocarbons together with variable mineral and salt deposits. Their presence on a nominally unused lens indicated that handling or assembly contamination was possible.
Case 1630 preview
Silicon-rich contamination, most consistent with silicone, was entrapped within and distributed over the electroplated tin leads. It prevented effective solder wetting and produced weak solder-to-lead interfaces that fractured readily.
Case 1303 preview
One pixel failed because a large copper-plating skip opened a package via. Other pixels had intact vias and solder joints; electrical isolation and section evidence instead supported fractures in encapsulated aluminum bond wires.
Case 1964 preview
The physical evidence established surface arcing and severe current damage around the power-connector joints, accompanied by shorted protection devices. It did not conclusively distinguish a connector-initiated short from an internal circuit short that subsequently overloaded the connector.
Case 88 preview
Internal wire strain-relief loops reduced the load-bearing polyurethane area and concentrated stress at their ends. Cracks then initiated at available weak points: an apparent hard inclusion in one assembly and a molding interface in the other.
Case 392 preview
Incomplete adhesive fill most likely caused the delamination. High points on the rough backing surface appeared to set the bondline gap, leaving substantial regions of the opposing gold-plated ceramic with little or no adhesive contact.
Case 2328 preview
The SAC joints underwent brittle interfacial fracture at or near the tin-nickel intermetallic/electroless-nickel-phosphorus boundary under high-rate shock loading. The assemblies appeared nominal and did not exhibit black-pad characteristics.
Case 2504 preview
Both devices failed through gross electrical overstress. Fused copper in the controller and melted gold in the protection diode demonstrated extreme localized heating, although the sequence between an initiating ESD event and secondary overcurrent could not be resolved.
Case 1822 preview
Copper migration formed conductive paths between internal signal traces and ground lands through mechanically damaged laminate and adhesive. Crazing, measling, and resin/glass separation supplied the pathways, with chloride contamination potentially contributing.
Case 2246 preview
The joints fractured brittlely at the electroplated nickel/Ni-Sn intermetallic interface. Plating construction and intermetallic thickness appeared generally normal, so the evidence did not distinguish high-rate overstress from a less-visible interfacial weakness.
Case 2281 preview
The expected black-pad indicators were absent. Brittle interfacial fractures were instead associated with severe board delamination and limited board-side intermetallic development, supporting mechanical loading potentially aggravated by marginal reflow.
Case 2040 preview
Fracture correlated with internal delamination or knit-line flaws between green ceramic tape layers created during co-firing. Flaw orientation relative to the mounting pad influenced whether the bead fractured.
Case 1849 preview
Potassium-rich corrosive contamination attacked the termination solder and exposed oxidized nickel-tin intermetallic that would not wet. Porous copper-nickel metallization and a discontinuous nickel barrier enabled penetration and retention of contamination.
Case 818 preview
Loose or missing strands and potting ingress created unstable electrical contact within under-compressed crimps. Fractured barrels and misregistered bores added mechanical instability.
Case 1069 preview
Condensed moisture combined with chloride, bromide, potassium, and other ionic residues to form a corrosive electrolyte. Porous, variable, separated, or locally missing plating increased access to the copper base.
Case 1821 preview
Thermal-mechanical overstress during secondary reflow or rework separated an internal layer connection from its plated-through hole. The same event rotated lands and fractured nearby copper and laminate.
Case 2323 preview
Package warpage produced the greatest solder-joint height at the BGA corners and stretched the corner balls into hourglass-shaped columns. The examined joints nevertheless showed acceptable wetting and developed copper-nickel-tin intermetallic, while the geometry increased susceptibility to head-in-pillow formation.
Case 253 preview
Non-radial or non-uniform radial loading was the primary failure mechanism. Axial loading displaced one wear track, a setscrew produced localized radial loading and ball spalling, and shaft misalignment damaged a cage. Corrosion and particulate contamination accelerated wear.
Case 1020 preview
The wire failed by fatigue followed by tensile rupture of the remaining cross-section. The apparent fatigue origin was separate from the nearby surface groove, and the final region displayed ductile dimple morphology.
Case 1401 preview
Mechanical damage bent the lead inward toward the package body, shifted its contact point to the extreme rear of the pad, and raised it above the mounting plane. The lead therefore failed to contact the solder deposit even though the materials and reflow process were satisfactory.
Case 1836 preview
Localized overheating around one pin damaged chlorinated potting material and created a corrosive ionic environment. With voltage applied, copper, nickel, and gold species migrated from the damaged pin toward the adjacent pin, producing the leakage path.
Case 1886 preview
The PCBA header contacts were not supported as the primary defect source. Fused tin, excessive copper-tin intermetallic growth, arcing damage, and nickel transferred from the mating contacts instead indicated electrical heating involving the mated contact system.
Case 212 preview
Oversized connector-retainer washers interfered with the mounting frame and bent the PWB. Combined bending and shock stress produced a radial crack from a screw-hole wall through the upper laminate layers and both internal signal traces.
Case 830 preview
An overvoltage exceeded the dielectric strength of the PTFE insulation. Internal breakdown carbonized the polymer and vaporized brass from the conductor, forming a conductive bridge to the grounded case.
Case 1420 preview
Fracture initiated at a small scratch, gouge, or pit in the stainless-steel stamping. Intact gold conformed to the defect, demonstrating that it existed before plating, while the small flaw size indicated limited mechanical margin in the dome design.
Case 1079 preview
The concurrent failures and distributed internal damage supported a high-voltage transient or possible reverse-bias event affecting the capacitor array. The evidence did not support moisture contamination as the primary mechanism despite the failure occurring after humidity testing.
Case 2089 preview
Corrosion of the extremely thin nickel-chromium resistor layer was the most likely failure mechanism. An open coating void, chlorine and sulfur contamination, and poor coating adhesion provided routes for contaminants and moisture to reach the functional film.
Case 2527 preview
The plating on both sides of the contact pair was uniform and generally met specification, with no anomaly capable of explaining the premature wear. The evidence redirected the investigation toward mechanical factors such as shock and vibration.
Case 270 preview
A voltage transient on the shutdown-control signal was the most likely initiating event. The internal damage trail included a fused PWB trace, damage to control circuitry, and emitter-collector shorting of power FETs.
Case 761 preview
The available evidence did not isolate a single root cause. Contamination-filled voids influenced some solder fractures, possible wetting or board-finish issues affected some interfaces, and one sectioned device contained a complete die fracture that could itself explain electrical failure.
Case 1321 preview
The solder joints were under-designed for the mechanical loads encountered in use. Cyclic terminal bending produced low-cycle solder fatigue, PTH-barrel fractures, laminate damage, and permanent joint distortion.
Case 467 preview
The nonwetting was most consistent with a combined mechanism: copper oxidation during first-side reflow reduced the solderability of pads intended for second-side assembly, while silicone and halide contamination further obstructed wetting and accelerated surface degradation.
Case 1668 preview
Electrochemical migration beneath the devices was the most likely cause of the leakage. Ionic contamination, voltage bias, and moisture acted through large adhesive voids and poorly bonded interfaces that provided protected capillary paths between conductors.
Case 1749 preview
The joints separated because the Kovar pin base metal ruptured beneath the nickel plating. Circumferential strings of voids, included material, and disturbed metal formed a weak subsurface region that predated soldering and plating.
Case 216 preview
Reverse-bias stress was the leading explanation for localized electrical breakdown and alloying at the tantalum-slug to manganese-oxide interface. Moisture-assisted degradation remained an alternative if reverse-bias transients could be eliminated.
Case 245 preview
The two LEDs had different internal failure mechanisms. One contained a bond wire fractured in shear near its wedge bond; the other contained a fine horizontal die crack capable of opening and closing under mechanical or thermal-mechanical loading.
Case 2048 preview
Corrosion of the nichrome resistance film was the most likely cause of the open circuit. Systemic voids in the lacquer body near the end caps created moisture-ingress paths to the extremely thin functional film.
Case 1341 preview
Radial cracks through the seal glass, most likely caused by excessive soldering heat at the pins, provided terminal-to-case paths that were filled with conductive zinc-chloride flux residue.
Case 1565 preview
Phosphorus-associated corrosion of aluminum bond pads was the most likely failure mechanism. Aluminum loss explained an open bond-pad connection, while electrolyte and migrated aluminum could also account for reduced signal-to-signal impedance.
Case 843 preview
Large pits formed in the Nitinol wire before gold plating and reduced the load-bearing cross-section until the remaining metal failed by ductile rupture. The condition was associated with a pre-plating process anomaly rather than an alloy difference.
Case 1333 preview
Package warpage most likely fractured the semiconductor die. The crack extended parallel to the die plane and coincided with local molding-compound delamination, while the examined solder joints remained acceptable.
Case 1600 preview
Mechanical shock fractured the transformer bobbin, while solder balls on exposed windings likely created shorts and reduced inductance.
Case 1727 preview
Excessive operating temperature most likely evaporated the volatile electrolyte, breached the positive-terminal seals, and left the failed capacitors internally dry with little remaining capacitance.
Case 2245 preview
Chlorine- and sulfur-driven corrosion produced two electrical effects: metallic migration across the resistor exterior created moisture-dependent shorts, while corrosion of the steel end-cap connections created internal open circuits after the assembly dried.
Case 2427 preview
Arcing at the GFI test-switch contacts was the most likely common failure mechanism. In the hard-failed unit, the contacts welded closed and overstressed the test circuit, vaporizing copper traces and thermally damaging a circuit actuator.
Case 2499 preview
The open circuit resulted from a bond-wire fracture immediately above the die bond. Thermal or mechanical tension was the likely applied stress, while off-center wire geometry suggested that original bonding damage may have reduced the fracture margin.
Case 279 preview
The clips most likely failed by hydrogen embrittlement associated with hydrogen exposure during zinc stripping or replating. Residual chloride contamination was a separate corrosion risk.
Case 1833 preview
The available physical evidence did not support the BGA solder joints as the primary failure cause. The investigation needed electrical localization before additional destructive analysis.
Case 1053 preview
Trichloroethylene cleaning solvent most likely attacked and breached the rubber seals, introducing chlorine-bearing material that drove internal anode corrosion and capacitor failure.
Case 1750 preview
The capacitors most likely shorted internally through fabrication anomalies that included distorted electrode plates, voided nickel conductors, and dielectric irregularities between adjacent plates.
Case 700 preview
Reflow-related molding-compound delamination most likely produced a die crack in one device and enabled bond-pad corrosion in the other.