PCB Manufacturing Quality Assurance Services
PCB QUALITY ASSURANCE :Prevent failures before they happen
PCB reliability and quality assurance services for electronics manufacturing companies for PCB cross sectioning, solder joints testing, Passive failures, PCB X-ray and CSAM inspections.
PCBA's Assembly Quality Control
Common PCB Components Failures
- Capacitors : Common failures in capacitors mounted on PCBs include cracking, corrosion, electrolyte leakage, dielectric breakdown, and capacitance drift.
- Resistors : Typical resistor failures are burn-out, resistance drift, cracking, corrosion, and delamination.
- Inductors & Coils : Frequent issues include wire breakage, core cracking, shorted turns, magnetic saturation, and corrosion.
- Transformers : Most common transformer failures are due to insulation breakdown, shorted windings, core saturation, thermal aging, and mechanical damage.
- Fuses : Failure modes often include nuisance blowing, corrosion, and mechanical fatigue.
- Varistors (MOVs) : Typical problems are cracking, thermal runaway, clamping voltage degradation, and surface tracking.
- Thermistors : Common failures include resistance drift, cracking, and overload damage.
- Ferrite Beads & Filters : Usual defects are core cracking, resistance increase, and magnetic losses.
- Crystals & Oscillators : Failures often involve frequency drift, cracking of the quartz element, aging effects, and loss of oscillation.
- Diodes (as passive rectifiers/clamps) : Issues include open junctions, short circuits, thermal runaway, and leakage current increase.
- Connectors & Sockets : Failures include fretting corrosion, plating wear, poor contact retention, cracking of housings, and high contact resistance.
- Relays (when used in low-power PCBs) : Common issues are coil burnout, contact wear, sticking contacts, and insulation degradation.
PCBA Cross Section
1. Cross-Section Analysis (Microsectioning)
- PCB sectioning involves precision cutting, mounting, and polishing of PCB samples to expose internal layers.
- Inspected using optical microscopy or Scanning Electron Microscopy (SEM).
- Solder joint integrity (voids, cracks, intermetallic growth)
- Plated Through Hole (PTH) quality (barrel fill, plating thickness, cracks).
- Delamination or voids in dielectric layers.
- Common failures due to Internal bond quality of components and laminate adhesion.
- Material defects such as cracks, corrosion, or inclusions.
2. Metallurgical & Material Testing
- PCBs rely heavily on the quality of base materials and metallization. Metallurgical analysis helps identify issues at the microscale that can lead to electrical failure.
- Solder Joint Metallurgy : Intermetallic compound (IMC) thickness, microcracks, and solder alloy phase analysis.
- Copper Plating & Coatings: Thickness measurement, grain structure analysis, detection of voids and cracks in PTH.
- Corrosion & Oxidation Studies: Identifying electrochemical migration, whiskers, or chemical degradation.
- Material Compatibility Testing : Glass fiber reinforcement quality, resin distribution, and filler content in PCB laminates.
- Solderability Testing & Solder Joint : Is one of the critical factors in PCB reliability. Poor wetting, voiding, or excessive intermetallic compound (IMC) growth can compromise both mechanical strength and electrical performance of joints. At Nanowatts Tech, we conduct solderability assessments and metallurgical analysis to detect such issues before they lead to field failures.
PCBA's Inspection
X-ray Inspection
1. Solder Joint Voids & Defects
- Detects voiding in BGA, QFN, and other bottom-terminated components.
- Identifies incomplete reflow, cold solder, or solder bridging.
2. Component Placement Issues
- Reveals lifted pads, insufficient solder wetting, or tombstoning defects.
- Detects misalignment and coplanarity issues in fine-pitch assemblies.
3. Layer & Via Integrity
- Inspects internal cracks or delamination in multilayer boards.
- Detects voids and non-uniform plating in microvias and through-holes.
4. Advanced 3D / CT Scanning / CSAM Inspection
- Allows reconstruction of internal layers for failure localization.
- Provides detailed insight into solder volume distribution and void percentage.
- X-ray inspection is a non-destructive method that allows internal visualization of PCBs without cross-sectioning. It is especially valuable for high-density and multilayer boards where critical features are not visible externally.
- CSAM (Confocal Scanning Acoustic Microscopy) : Non-destructive technique used to detect internal delamination, cracks, and voids in PCBs and IC packages, ensuring structural integrity without damaging the sample. CSAM is especially useful in high-reliability industries like automotive, aerospace, and medical electronics, where hidden internal defects can lead to catastrophic failures if undetected.
PCB Plastic Fixtures, Connectors, and Housings
- Thermal Aging & Degradation : Plastics soften, warp, or lose strength under repeated solder reflow or operating temperatures.
- Creep & Fatigue : Long-term stress causes dimensional changes, leading to connector misalignment or poor retention force.
- Cracking & Delamination : Molding defects or mechanical stress can cause cracks in housings and connector shells.
- Chemical Resistance Issues : Exposure to fluxes, solvents, or cleaning agents weakens insulation materials.
- Contact Wear & Fretting : Mechanical wear at connector interfaces leads to high contact resistance or intermittent failures.
- Moisture Absorption : Plastics absorb moisture, causing swelling, blistering, or “popcorning” during reflow.
- Apart from copper traces and solder joints, plastic components and connectors play a vital role in PCB assemblies. Failures in these materials often lead to mechanical instability, poor electrical contact, or environmental degradation.
- We perform a range of mechanical, thermal, and material analyses to ensure reliability of these non-metallic parts.