Scanning Acoustic Microscopy (SAM)
Scanning Acoustic Microscopy (SAM) is a non-destructive imaging technique that employs ultrasound waves to investigate the internal structure, defects, etc. It is most widely used for identification of sub-surface imperfections within devices, assemblies, and materials that cannot be resolved by optical microscopy. Other applications include failure analysis, to detect hidden defects in elastic, biological samples, and to inspect voids and delaminations in semiconductors. Also called Acoustic Micro Imaging (AMI) and Scanning Acoustic Tomography (SAT), a lateral resolution lower than 30 μm and a vertical resolution of a few nanometers can be achieved with this technique.
In SAM, a piezoelectric transducer sends ultrasonic waves towards the sample that get scattered, absorbed, or reflected at the media interfaces. An image is created from the signal reflected by the sample. Air and water-filled blisters, delaminations, cracks, and micro-fillers can be differentiated at the sub-micron level by this technique.
- Diagnosis of the damaged area of adhesive bonding of metals and fiber-reinforced composites, biocomposites, and biomaterials
- Imaging the morphology, location, and size distribution of defects in printed circuit boards, underfills, voids, wire bonds, discrete components, and wafers
- Imaging of the internal structure of ceramic capacitors and MEMS
- Indication of the residual stress gradients during the scratch testing of the coating systems
- Study of degradation and cathodic disbondment behavior of the coating
- Detection of porosity in aluminum casting
- Detection of undersized and large resistance spot welds and low penetration depth of laser weld seam
- Non-destructive tool for failure analysis purposes
- The use of ultrasound waves enables the specification of a focal point by limiting diffraction, thus permitting more accurate results and increased data
- Ability to probe subsurface regions where fractures and delaminations may be concealed from the view of traditional light-optical and electron-optical instruments
- Wide range of low to ultra-high transducer frequency (~GHz) and focal lengths for optimized penetration and resolution for a variety of samples
- Submicron delamination detectability (< 0.2um)
- Slow processing time
- Using high-frequency sound waves creates a greater potential for artifacts of surface preparation
- Limited to polymer films with lower thickness, since at typical frequency, the penetration depth of ultrasound wave is limited to ~ 100 μm
- Reduced imaging through multiple interfaces and layers, such as soft or porous materials
- Coatings and Adhesives
- Medical Science
- Polymers and Composites
- Defense and Aerospace
- Sage Analytical Lab, LLC
- EAG Laboratories Inc.
- Priority Labs, Inc.
- AcousTech, Inc.
See Best Metrology Services
Secondary Ion Mass Spectroscopy or SIMS is a tool for composition analysis of metals, semiconductors, polymers, biomaterials, minerals, rocks, and ceramics.
Profilometry is the measurement of surface topography. It is used to measure surface roughness, coating thickness variation, flatness, surface curvature,