Modern electronic components are expected to operate reliably for years under demanding conditions. Whether used in space systems, aerospace electronics, automotive control units, medical devices or industrial power electronics, their reliability and electrical performance depend on the quality of the used materials and manufacturing processes.
While functional testing is the most direct and obvious method for evaluating the performance of electronic components, it provides only limited insight into the underlying causes of defects or failures. In contrast, microanalytical investigations enable detailed verification of the internal structure, material composition and manufacturing quality of components. In the event of failures, those tools can be used to identify the root cause of the malfunction and provide valuable information for process optimisation and product improvement. At AAC, we provide comprehensive microstructural analysis and materials characterization for electronic components. Our experts combine advanced analytical methods (such as SEM/EDS) with decades of experience in materials science to identify failure mechanisms, optimize manufacturing processes and qualify materials and processes for high-reliability applications.
Assessment of Electronic Components at AAC
We assess electronic components for our customers across the complete product lifecycle – from prototype development to qualification of processes and tools and failure analysis. A wide range of different electronic components has been analysed in recent projects, such as printed circuit boards (PCBs), electrical contacts, connectors, solder joints, etc.
By combining multiple analytical techniques, AAC helps to identify the root cause of a failure rather than documenting its consequences:
- Metallographic sample preparation
Electronic assemblies can contain fragile combinations of metals, ceramics, polymers and semiconductor materials. For a typical metallographic assessment, the samples are sectioned, mounted and polished.
- Optical microscopy
The resulting cross-section preserves delicate interfaces and is investigated by optical microscopy to assess the solder joint quality by evaluating cracks, voids, porosities, delaminations and manufacturing defects.
- Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS)
To obtain a more detailed insight, SEM/EDS is used to enable detailed examinations of complex microstructures and to identify and quantify elemental compositions.
Examples of electronic components assessed in recent projects at AAC
Vertical electrical interconnections – commonly referred to as VIAs (Vertical Interconnect Access) – are electrical connections between two or more metal layers of a printed circuit board (PCB) or integrated circuit. The geometric features as well as the microstructure and the quality of the wetting are assessed.
Figure 1: Assessment of VIA connecting different layers of a printed circuit board (PCB): Light-microscopic image of cross section
Failure analysis of a transistor package: To assess possible failure mechanisms, the lid is opened to investigate the sub-components. Details reveal proper electrical contacts.
Figure 2: SEM images of transistor; left: Overview image of the opened transistor lid; centre & right: details revealing proper electrical contact
Assessment of high-reliability soldering according to ECSS Q-ST-70-38
The ESA standard ECSS Q-ST-70-38 defines the procedures to investigate soldering joints between components and the printed circuit board (PCB). In addition to the light-microscopic investigations on the cross-section (as defined in the standard), SEM investigations reveal the microstructure of the soldering.
Figure 3: Microstructural characterization of the solder joint reveals porosity and structural imperfections.
ACrimp assessment according to ECSS Q-ST-70-26
According to the requirements defined in the ESA standard ECSS-Q-ST-70-26C, a metallographic cross-section is prepared through the crimp joint revealing the area of the maximal compression. The cross-section is assessed to evaluate the following acceptance criteria
- The cross-section is free from contaminations.
- The crimp barrel is evenly deformed.
- Voids occupy less than 10 % of the cross sectioned area of the wire volume.
- All strands are deformed from their circular cross section approaching a hexagonal shape.
- No indentations or fracturing of the deformed barrel are detected.
More details on the investigation of crimp contacts can be found in our blog: Microanalytical assessment of crimp-joints
Looking for support with your electronic components?
The profound assessment of the microstructure is essential for a detailed failure investigation, for supplier qualification and for process validation. Our specialists are ready to help.
Contact AAC to discuss your requirements and discover how our microanalytical expertise can support the reliability and performance of your electronic components: office@aac-research.at or visit us at Aerospace & Advanced Composites: Space Engineering & Technology
