Ezpay科技

Failure Analysis of PCB/PCBA

1. Introduction 

The technology level and quality of PCB and PCBA products  are also facing serious challenges, along with the high density of electronic products and lead-free of electronic manufacturing. PCB design、production and processing and assembly process needmore strict process and control raw materials. Due to the technique and technology is still in the transition period at present, customer knowledge of PCB manufacturing and assembly exist bigger difference. Sofailures similar to theelectric leakage, open circuit (circuit, hole), rack of fusion and blasting plate layersare of common occurrence.It often causes the quality responsibility of the dispute between suppliers and users,which led to the serious economic loss.Failure analysis of PCB and PCBA failurephenomenon, verification through a series of analysis, identification the reasons for failure and mining failure mechanism make important significance to improve product quality, improve production technology and arbitrate failure accidents.

2. the service object

Printed circuit board and component (PCB&PCBA) producers:confirm the product quality, analyzes the various problems in the process of production, explore the mechanism of the root of the problem, providereference comments of improving product design and process for production  ;

Printed circuit board and subassembly (PCB&PCBA)suppliers/distributors：control incoming quality, increase the use confidence of user, enhance brand value;

Printed circuit board assembly (PCBA) overall business: eliminate the potential problems in the process of production in a timely manner, improve the reliability of products, reduce the risk of liability.

3. Produce benefit

Help materials manufacturers understand the status of the product quality, analysis and evaluation about the present situation of process, optimize and improve development plan and production process of product;

Find out the fundamental reason for failure in the electronic assembly, provide effective electronics assembly process improvement program, reduce the production cost;

Improve the reliability of using and product percent of pass of finished product,reduce maintenance costs, improve enterprise brand and competitiveness;

Clear the cause of product failure responsibility, provide the basis for the judicial arbitration.

Analyzed types of PCB/PCBA:

Rigid PCB, Flexible printed circuit board, Rigid-flex PCB, Metal base copper clad laminate, Communication PCBA, Lighting PCBA

4. the failure mode mainly aimed at (but not limited to)

Blasting plate/layered/blister/surface	contaminationshort circuit and open circuit
Bad welding, welding plate tin, tin bad on the pin	Migration: corrosion electrochemical migration, CAF

5. common failure analysis technology

nondestructive examination

thermal analysis:

appearance inspectiondifferential scanning calorimetry（DSC）

X-ray detectionThermal mechanical analysis (TMA)

Three-dimensional CT detectionThermogravimetric analysis (TGA)

C-SAM detectiondynamic mechanical analysis (DMA)

nfrared thermal imagingCoefficient of thermal conductivity (steady state heat flux method, laser scattering method)

surface element analysis

Scanning electron microscopyand energy spectrum analysis (SEM/EDS)

Micro infrared analysis (FTIR)

Auger electron spectroscopyanalysis (AES)

X-ray photoelectron spectroscopy analysis (XPS)

Secondary ion mass spectrometry (TOF-SIMS)

electric performance test

The breakdown voltage, Voltage resistance, Dielectric constant, Electric migration

destructive inspection

Dyeing and penetration testing

Slice analysis:metallographic, focused ion beam (FIB) sample preparation, ion milling (CP) sample preparation