SnAg Solder Research Articles

Eutectic Solidification Morphologies in Rapidly Solidified Hypereutectic Sn–Ag Solder Alloy

The effect of rapid solidification upon hypereutectic Sn–Ag solder alloy has been investigated using a 6.5 m drop tube. Powder sizes ranging from > 850 to < 38 μm were produced, with equivalent cooling rates of 250 to 14,800 K s−1 for 850 and 38 μm droplets, respectively. At all cooling rates investigated, dendritic β-Sn was observed as the primary solidification phase, not proeutectic Ag3Sn as predicted by the phase diagram. The volume fraction of interdendritic eutectic was observed to decrease with increasing cooling rate, with the Ag concentration in the residual interdendritic liquid estimated at 12.5–15 wt pct Ag, far in excess of the eutectic concentration of 3.8 wt pct. Much of the Ag3Sn observed within the eutectic had a blocky, divorced eutectic appearance. A model is proposed which can explain these observations in terms of sluggish nucleation of the Ag3Sn intermetallic, coupled with a metastable phase diagram that permits significant supersaturation of Ag at modest undercooling.

Combined effect of Ag element and temperature gradient on the formation of highly orientated Sn grains in micro solder joints

Sn–Ag solders are widely used for advanced electronic packaging. The combined effect of Ag element and temperature gradient (TG) on the formation of Sn grains in Cu/Sn-xAg/Cu micro solder joints was elucidated systematically. Numerous small-sized β-Sn grains were formed in both Cu/Sn/Cu and Cu/Sn-0.5Ag/Cu micro solder joints after reflow with or without TG. The Cu/Sn-0.5Ag/Cu joint was found to have more twinning β-Sn structures. The formation of the multiple β-Sn grains in these two joints was attributed to the presence of multiple tetrahedral metastable short-range order (SRO) structures which acted as nuclei for the nucleation and growth of β-Sn. The existence of TG slightly enhanced the preferred orientation characteristics of Sn grains. For the joints with Ag content was or higher than 2 wt%, several Sn grains were formed without TG, while a single or highly oriented Sn grains were observed with TG. The number and orientation of Sn grains were affected by the combined effect of Ag element and TG significantly. The β-Sn grains formed without TG were based on the {101} type cyclic twinning configuration clusters that stabilized by Ag atoms and acted as nuclei. The formation of a single or highly preferred β-Sn grains was benefit from the combined effect of Ag element and TG. The results provide theoretical guidance for optimizing the composition of Sn–Ag solders and controlling the microstructure of the joints, thereby contributing to the advancement of electronic packaging technologies.

Microstructural Evolution and Phase Transformation on Sn–Ag Solder Alloys under High‐Temperature Conditions Focusing on Ag3Sn Phase

This study investigates the microstructural and phase transformations in Sn–Ag solder alloys under high‐temperature conditions, utilizing X‐ray diffraction, scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) analyses. Analytical techniques are employed pre‐ and postcontrolled thermal cycling from 30 to 180 °C, aimed at emulating solder reflow processes. The analysis at room temperature demonstrates pronounced crystalline peaks, suggesting a preferred orientation within the crystal structure. Upon heating, peak broadening suggests grain growth and the onset of recrystallization. SEM and energy‐dispersive spectroscopy analyses corroborate these findings, displaying a fine‐grained, well‐distributed microstructure with a homogenous composition of Sn and Ag elements. EBSD provides insights into the orientation and texture of grains, revealing a weak‐to‐moderate texture across the phases. Postexperiment data indicate a dominant presence of larger grains and significant variation in grain size, with an area‐weighted mean grain size of 68.47 μm and a standard deviation of 8.68 μm; this suggests significant grain growth and coarsening of the Ag3Sn intermetallic compounds. These structural evolutions have crucial implications for the mechanical properties and reliability of the solder alloy in electronic assemblies, underscoring the need for further exploration of lead‐free solder materials in the electronics industry.

EBSD characterization of graphene nano sheet reinforced Sn–Ag solder alloy composites

This research explores the effects of incorporating Graphene Nano Sheets (GNS) on the microstructural characteristics and mechanical behavior of Sn–Ag solder alloys. The research was driven by the need for environmentally friendly, lead-free solder alloys with enhanced mechanical and thermal properties. The methodology involved incorporating graphene into the Sn–Ag alloy through stir casting, followed by a series of surface preparation techniques. The composite samples were then examined using EBSD to analyze crystallographic orientations and SEM/EDS for surface morphology and elemental composition. XRD provided insights into phase transformations and structural changes. Key findings reveal that the addition of GNS significantly refines the grain structure of the Sn–Ag alloy, leading to a bimodal grain size distribution. This refinement is attributed to the role of GNS as a nucleation site during solidification. Moreover, the study demonstrates a pronounced alteration in the texture of the material, with an increase in low-angle grain boundaries post-GNS addition. This texture change is indicative of enhanced mechanical properties. The results also show a shift in the orientation distribution function (ODF), suggesting a stronger crystallographic orientation due to GNS. These findings suggest that GNS incorporation could lead to improved mechanical and thermal properties in Sn–Ag solder, making them suitable for high-performance electronic applications. The study concludes that GNS not only serves as an effective reinforcement in Sn–Ag solder alloys but also significantly alters their microstructural and textural characteristics, contributing to the alloy's potential application in environmentally conscious electronic manufacturing.

Understanding the corrosion protection effect by surface oxide film to underlying Sn solder substrate under thermal exposure condition

Oxide film formed on Sn-based lead-free solder surface plays an important role in protecting the solder joints in electronic devices. However, corrosion resistance of oxide film varied significantly under the effect of waste heat generated by electronic devices. In this work, the physicochemical properties of oxide film on pure Sn and SnAg solders were disclosed through analysing the corresponding electrochemical impedance spectroscopy (EIS) data using measurement and power-law models. The resolved data from EIS were fully corresponded to X-ray photoelectron spectroscopy and transmission electron microscope observations, which highlight the EIS approaches in illustrating the oxide film properties on Sn-based solder.

In Situ Study the Grooving Effect Induced by Ag Particles on Rapid Growth of Cu6Sn5 Grain at Sn-xAg/Cu Soldering Interface during the Heat Preservation Stage

Synchrotron radiation X-ray imaging technique was applied for in situ observation of Cu6Sn5 intermetallic compounds (IMC) growth in Sn/Cu and Sn-3.5Ag/Cu joints under isothermal temperature conditions of 250/300/350 °C and time duration of 1.5 h. The IMC in Sn-Ag solder was characterized by the formation of grooves during the interfacial reaction, and this can be attributed to the Ag content. Kinetically, the growth rate constants for the height of Cu6Sn5 were observed to increase with temperatures and the presence of Ag in solder. As compared to pure Sn solders, the Sn-3.5Ag solders were observed with interfacial IMC of greater height, smaller base width, and lowered aspect ratio.

Hybrid solder joints: the effect of nanosized ZrO2 particles on morphology of as-reflowed and thermally aged Sn–3.5Ag solder joints

The main number of current researches has been focused on the microstructure and mechanical properties of the Sn-based Sn–Ag–Cu-based solders, while various kinds of nanosized particles have been added. The synthesis and handling of ceramic nanosized powder are much easier than of metal nanoparticles. In addition, metal nanoparticles solved in solder joints during the soldering process or by thermal aging could behave as an alloying element similar to bulk metal additions, while ceramic nanoparticles retain their chemically inactive behavior in various thermal, thermo-mechanical, and electrical constraints. In some cases, the solved metal nanosized inclusions could increase the growth kinetics of the present intermetallic phases or even create new phases, which leads to more complexity in the predictions and simulations of chemical processes in the solder joints. Based on the assertions mentioned above, ceramic nanosized particles are industrially more favorable as reinforcing inclusions. On the other hand, there is no direct comparison in the literature between Sn-based Sn–Ag–Cu and Sn–Ag solder joints with similar ceramic nanoinclusions based on microstructural features and mechanical properties. In the present research, the Cu/flux + NPs/SAC/flux + NPs/Cu solder joints were produced with a nominal amount of 0.2 wt%, 0.5 wt%, and 1.0 wt% nanosized ZrO2 powder. The solder joints prepared via the above-described method are called in the literature as hybrid solder joints. The microstructure of the as-reflowed and thermally aged samples has been studied, especially at the interface solder/substrate. It has been shown that the minor additions of ZrO2 NPs lead to a decrease in the thickness of the Cu6Sn5 interfacial layer in the as-reflowed solder joints and a reduction in the growth kinetics of this layer, while the Cu3Sn interfacial IMC layer remains practically unaffected. Similar investigations were performed in our previous study but for both the hybrid and nanocomposite Sn–3.0Ag–0.5Cu solder joints. A comparative analysis of the impact of the ZrO2 nanoinclusions on the hybrid solder joints using Sn–3.5Ag and Sn–3.0Ag–0.5Cu has been performed.

Retrieval analysis of the Essure® micro insert female sterilization implant: Methods for metal ion and microscopic analysis.

The Essure® Device is a female sterilization implant comprised of four alloys (Ni-Ti, 316L SS, Pt-Ir and Sn-Ag) and Dacron fibers. As part of the mandated 522 post-market surveillance study, implant retrieval and metal-ion analysis methods were developed separate from patient clinical data, to quantify trace metal ions found in tissue and to assess implant degradation present. Three segments of tissue (proximal implant, distal implant, and tissue distal from the implant) stored in neutral buffered formalin, were retrieved. Tissue was prepared for metal ion analysis using inductively coupled mass spectrometry (ICP-MS). Implant sections from four patients, were analyzed using digital optical microscopy (DOM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Image analysis showed Sn-Ag solder corroded and elevated Sn ion levels in tissue proximal to the solder compared to tissues more remote in all cases observed. The 316L SS exhibited signs of degradation with high surface concentrations of molybdenum and chromium and low iron compared to the parent alloy. Evidence of elevated iron, chromium and nickel within the tissues and storage solutions combined with precipitation of an iron-calcium-phosphorous material on some implants indicate evidence of SS corrosion. Ni-Ti, Pt-Ir and Dacron appear to have no major damage. This study includes preliminary results as part of the ongoing 522 study and therefore no final conclusions regarding the device or patient data can be drawn from this present study until the entire 522 study is complete. STATEMENT OF SIGNIFICANCE: The Essure Device is a female sterilization implant that was implanted into approximately 750,000 women. The device is composed of polyethylene terephthalate fibers and 4 metal alloys, 316L stainless steel, Nickel-Titanium, Tin-Silver and Platinum-Iridium. Following an increase in patient reported adverse events, the FDA required a 522-post market surveillance study. As part of this study, implants are retrieved from patients via salpingectomy or hysterectomy. This study focuses on the development of the implant retrieval methods following surgery, with focus on measuring local tissue metal ions, their distribution and assessing the degradation of the implant without correlation to patient clinical condition.

Development of novel single-die hybridisation processes for small-pitch pixel detectors

Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. During the ASIC and sensor R&D phase, especially for small-scale applications, such interconnect technologies need to be suitable for the assembly of single dies, typically available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25 µm and 55 µm are presented in this contribution — an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing using support wafers, as well as a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The fine-pitch bump-bonding process is qualified with hybrid assemblies from a recent bonding campaign at Frauenhofer IZM. Individual CLICpix2 ASICs with 25 µm pixel pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50 µm to 130 µm. The device characterisation was conducted in the laboratory as well as during a beam test campaign at the CERN SPS beam-line, demonstrating an interconnect yield of about 99.7%. The ACF interconnect technology replaces the solder bumps by conductive micro-particles embedded in an epoxy film. The electro-mechanical connection between the sensor and ASIC is achieved via thermocompression of the ACF using a flip-chip device bonder. The required pixel pad topology is achieved with an in-house Electroless Nickel Immersion Gold (ENIG) plating process. This newly developed ACF hybridisation process is first qualified with the Timepix3 ASICs and sensors with 55 µm pixel pitch. The technology can be also used for ASIC-PCB/FPC integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the two interconnect processes and presents preliminary hybridisation results with CLICpix2 and Timepix3 sensors and ASICs.

Solid-state interfacial reaction of Sn-Ag solders with polycrystalline Cu and (0 0 1) Cu substrate

• For sn-Ag solder, the growth of Cu 3 Sn on (0 0 1)Cu is faster than on polycrystalline Cu in aging. • Ag increases the difference in Cu 3 Sn thickness on (0 0 1)Cu and polycrystalline Cu in aging. • Ag is beneficial to maintain the preferred orientation of Cu 6 Sn 5 in aging. The growth of Cu 3 Sn is associated with the formation of Kirkendall voids and is important to the reliability of solder joints. In this paper, the effect of Ag on the growth behavior of Cu 3 Sn on (0 0 1) Cu and polycrystalline Cu during aging was compared. Besides, the orientation evolution of Cu 6 Sn 5 on (0 0 1) Cu during aging was also investigated. Results suggested the growth rate of Cu 3 Sn on (0 0 1) Cu is higher than that of polycrystalline Cu during solid-state aging and the difference in the Cu 3 Sn layer thickness increases with the increases of Ag content in the solder. Moreover, the addition of Ag is beneficial to maintaining the preferred orientation of Cu 6 Sn 5 on (0 0 1) Cu during solid-state aging. The results have great help to deepen the understanding of the difference in growth behavior of intermetallic compounds on (0 0 1) Cu and polycrystalline Cu during aging.

Effect of Tin Grain Orientation on Electromigration-Induced Dissolution of Ni Metallization in SnAg Solder Joints.

In this study, symmetrical solder joints (Cu/Ni/SnAg2.3/Ni/Cu) were fabricated. They were electromigration (EM)-stressed at high (8 104 A/cm2) or low (1.6 104 A/cm2) current densities. Failures in the solder joints with different grain orientations under EM stressing were then characterized. Results show that Ni under-bump-metallurgy (UBM) was quickly dissolved into the solder joints possessing low angles between Sn c-axis and electron direction and massive NiCuSn intermetallic compounds formed in the Sn matrix. The diffusion rate of Ni increased with decreasing orientation grain angle. A theoretical model was also established to analyze the consumption rate of Ni UBM. Good agreement between the modeling and experimental results was obtained. Additionally, we found that voids were more likely to form in the solder joints under high EM stressing.

Fast prediction of electromigration lifetime with modified mean-time-to-failure equation

• Based on Onsager’s entropy production equation, the mean-time-to-failure equation for electromigration is derived. • Only need one set of data to predict the electromigration lifetime with this equation. • The cost and time can be saved for electromigration tests. Black’s mean-time-to-failure (MTTF) equation has been applied to predict electromigration lifetime in electronics for decades. It is an empirical equation, and at least three sets of data tested under two temperatures and two current densities are needed to determine the parameter n, activation energy E , and pre-factor A in the equation. Based on Onsager’s entropy production theory, we derived a modified MTTF equation, in which n = 2 becomes definite. The activation energy E is intrinsic for materials; for SnAg solder joints, we can take it as 1 eV. Therefore, we only need one set of data (one temperature and one current density) to determine the perfector A , for predicting the electromigration lifetime of the test samples. Our modified MTTF equation provides a fast and cost-saving method for accurate prediction of the electromigration lifetime for electronic products.

Effect of rotating magnetic field on the microstructure and properties of Sn-Ag-Sb lead-free solder alloys

PurposeThe purpose of this paper is to study the microstructure and properties of Sn-3.5Ag and Sn-3.5Ag-0.5Sb lead-free solder alloys with and without a rotating magnetic field (RMF).Design/methodology/approachOptical microscopy, scanning electron microscopy and X-ray diffraction were used to analyze the effect of an RMF on the microstructure of the solders. Differential scanning calorimetry was used to study the influence of the RMF on the thermal characteristics of the solders. The mechanical properties of the alloys were determined by tensile measurements at different strain rates.FindingsThe ß-Sn grains and intermetallic compounds for the Sn-3.5Ag and Sn-3.5Ag-0.5Sb lead-free solder alloys were refined under an RMF, and the morphology of the ß-Sn grains changed from dendritic to equiaxed. The pasty range was significantly reduced under an RMF. The ultimate tensile strength (UTS) of Sn-3.5Ag improved under the RMF, whereas the UTS of Sn-3.5Ag-0.5Sb decreased slightly. The addition of Sb to the Sn-3.5Ag alloy significantly enhanced the UTS and elongation (El.%) of the samples. The UTS of the solder increased with increasing strain rate.Originality/valueThe results revealed that the application of RMF in the molten alloy had a significant effect on its microstructure and mechanical properties. The thermal characteristics of the Sn-3.5Ag and Sn-3.5Ag-0.5Sb solder alloys were improved under the RMF. This research is expected to fill a knowledge gap regarding the behaviour of Sn-Ag solder alloys under RMF.

In Vitro Corrosion Assessment of the Essure® Medical Device in Saline, Simulated Inflammatory Solution and Neutral Buffered Formalin

The Essure® permanent contraceptive implant, comprised of four alloys (nickel-titanium, 316L stainless steel, platinum-iridium, and tin-silver solder) and Dacron (PET) fibers, has been approved for use in the US for about two decades. However, little has been published on this implant's biomaterials performance, and as this implant gains interest in terms of in vivo performance, methods of implant post-retrieval storage also need to be assessed. This study investigated the electrochemical properties and ion release profile of Essure® during storage in phosphate buffered saline (PBS), 10 mM H2O2/PBS, a simulated inflammatory solution, and 10% neutral buffered formalin (NBF) to investigate the corrosion behavior and metal ion release. First, a galvanic test method was used to measure the galvanic interactions between alloys within the device. Second, an ion-release study over 107 days was performed. Ions were measured using inductively-coupled plasma mass spectrometry and the implants were assessed using digital optical microscopy, scanning electron microscopy, and energy dispersive x-ray spectrometry. The tin-silver (SnAg) solder continuously corroded in PBS and H2O2/PBS. In the presence of H2O2, nickel and titanium ions were released from the nickel-titanium (NiTi) coil, whereas release of these ions was minimal in PBS alone. Overall, corrosion of the SnAg solder, which holds the NiTi and 316L SS together, was significant in both PBS and H2O2/PBS and may result in loss of connection of the NiTi and 316L stainless steel portions of the implant. Storage in NBF exhibited very low corrosion rates for all alloys and low levels of ion release were observed indicating that formalin storage minimally affects the implant's corrosion status. Statement of significanceThe Essure® device is an FDA premarket-approved female permanent sterilization device containing four different metal alloys and poly(ethylene terephthalate) polymer fibers. Significant concerns related to this device have been raised by the FDA since its introduction in 2002. This study is the first published in vitro work to specifically assess the corrosion mechanisms in this multi-alloy device and the role of different solution environments, including formalin storage, inorganic physiological saline and a simulated inflammatory condition. Significant evidence of corrosion of the tin-silver solder is documented, the release of Ni and Ti under simulated inflammatory conditions, and the relative inertness of storage of these implants in neutral buffered saline is presented. The tin-silver corrosion corroborates recent clinical evidence of tin corrosion products in tissues adjacent to these devices in vivo.

Interfacial reaction between Sn-Ag solder and electroless Ni-Fe-P diffusion barriers with different internal microstructure

The increasing operation temperature of electronic devices significantly accelerates the growth of Cu-Sn intermetallic compounds (IMCs) at the interfaces of Sn-Ag solder/Cu substrate which deteriorates the device reliability. A robust diffusion barrier is thus required to suppress the interfacial reactions between solders and substrates. In this work, electroless Ni-Fe-P coatings with three different internal microstructure were prepared to compare their interfacial reactions and diffusion barrier properties in Sn-Ag solder interconnects. Ni-Fe-P coatings can effectively suppress the excessive growth of interfacial IMCs in Sn-Ag solder interconnects during reflow process. It has been found that the Ni-Fe-P coatings with crystalline structure had great influence on IMCs formation and morphology at Sn-Ag/Ni-Fe-P interfaces. Among three types of Ni-Fe-P coatings, the crystalline Ni-Fe-P exhibited the optimal diffusion barrier property owing to the presence of a uniform and thinnest FeSn2 layer at the interface, while the amorphous Ni-Fe-P coating was less effective due to the irregular and thickest Ni3Sn4 IMCs formed at the interface.

Microstructure and properties of Sn-Ag and Sn-Sb lead-free solders in electronics packaging: a review

Microstructure and properties of Sn-Ag and Sn-Sb lead-free solders in electronics packaging: a review

Low Resistance and High Electromigration Lifetime of Cu-To-Cu Joints Using (111)-Oriented Nanotwinned Copper

Cu-to-Cu joints of 30 mm in diameter were fabricated using (111)-oriented nanotwinned copper at 300 °C for 20 min in N2 ambient. The joints possess excellent electrical properties. The average resistance and specific contact resistivity are 4.1 mΩ and 3.98 × 10 -8 Ω·cm 2 , respectively for an as-fabricated Cu joint. With a second step annealing at 400 °C, the resistance can be reduced to 3.27 mΩ due to grain growth across the joint interface. There is 50% resistance reduction compared to SnAg solder joints with the same diameter. The electromigration lifetime for Cu-to-Cu joints is at least 750 times longer than solder joints.

Reliability evaluation of ultra thin 3D-IC package under the coupling load effects of the manufacturing process and temperature cycling test

In the development of semiconductor packaging technology from planar to three-dimensional vertical integration, chip interconnection density has increased, and the distance of signal transmission has dropped to improve overall device performance. In this research, an architecture composed of through‑silicon via (TSV) and solder microbump (μbump) is utilized to assemble an ultra thin-type chip into a three-dimensional integrated circuit (3D-IC) package. To explore the influence of residual thermomechanical residual stress induced during the manufacture of the 3D-IC package on the subsequent reliability of the thermal cycling test (TCT), this study establishes a nonlinear simulation methodology for investigating the coupling effect of the manufacturing process and the TCT. The plastic and creep behaviors of the solder μbump are considered in the finite element modeling. The concerned geometric dimensions and underfill materials are also parametrically analyzed. Furthermore, the inelastic strain accumulated in the crucial SnAg solder μbump is examined. Results indicate that the residual strain in the manufacturing process causes an obvious packaging warpage and converges at the subsequent TCT stage. The creep of the solder μbump increases up to 50% in thermal cycling, thereby highlighting the importance of considering the creep model. Moreover, the parameterization of chip thickness can minimize the inelastic strain increment of the solder μbump, and the low Young's modulus of the underfill materials exerts a significant effect on the warpage of the packaging module and the stress compliance of the μbumps.

A perspective on effect by Ag addition to corrosion evolution of Pb-free Sn solder

The corrosion effect by Ag addition to Sn solder has been explored with consideration of the formed surface oxides film. Results indicate that the oxides film on Sn-Ag solder maintains a much shorter duration to NaCl electrolyte attack than that on pure Sn solder. The film thickness variation among phases of Ag3Sn and β-Sn and the defects especially at boundaries facilitate Cl− preferential adsorption. After the oxides film deterioration, galvanic effect between Ag3Sn and β-Sn comes into play for further corrosion. This observed evolution behavior provides a practical perspective to corrosion of Ag-alloyed Sn solder with an oxides film covering.

Characterization of femtosecond laser ablation processes on as-deposited SnAg solder alloy using laser ablation ionization mass spectrometry

Laser ablation ionization mass spectrometry studies on polished surface structures of hard, high melting point multicomponent interconnect structures using our femtosecond-laser time-of-flight mass spectrometer have previously been proven capable of providing spatially resolved chemical depth profile data at the micro- and nanometer level. Transfer of experimental protocols tailored to suit such type of samples to low melting point materials with high surface roughness, however, is highly challenging, as thermal effects caused by interactions of the laser light with the targeted surface play a severe role in the latter case and may significantly deteriorate the analysis outcome. In this contribution we present a dedicated and detailed comparison of the distinct effects of near infrared and ultraviolet irradiation on the ablation process in femtosecond laser ablation ionization mass spectrometry studies on low melting point materials. As model substrate we use high surface roughness, as-deposited SnAg solder alloy, a material of major industrial relevance in microchip fabrication. We will demonstrate herein that polydimethylsiloxane replica casting is possible also from granularly structured, high surface roughness samples. Characterization of the laser ablation craters as well as of their polydimethylsiloxane replicas is carried out by mass spectrometric analysis, Scanning Electron Microscopy imaging, and furthermore, as a novel approach for this purpose, by white light interferometry. Integration of all obtained results significantly adds to the detailed understanding of laser ablation processes on low melting point, high surface roughness materials and allows identifying optimal depth profiling conditions for these demanding samples.