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This study aims to analyze the shear strength and fracture mechanism of full Cu-Sn IMCs joints with different Cu₃Sn proportion and joints with the conventional interfacial structure in electronic packaging.

The Cu-Sn IMCs joints with different Cu₃Sn proportion were fabricated through soldering Cu-6 μm Sn-Cu sandwich structure under the extended soldering time and suitable pressure. The joints of conventional interfacial structure were fabricated through soldering Cu-100 μm Sn-Cu sandwich structure. After the shear test was conducted, the fracture mechanism of different joints was studied through observing the cross-sectional fracture morphology and top-view fracture morphology of sheared joints.

The strength of joints with the conventional interfacial structure was 26.6 MPa, while the strength of full Cu-Sn IMCs joints with 46.7, 60.6, 76.7 and 100 per cent Cu₃Sn was, respectively, 33.5, 39.7, 45.7 and 57.9 MPa. The detailed reason for the strength of joints showing such regularity was proposed. For the joint of conventional interfacial structure, the microvoids accumulation fracture happened within the Sn solder. However, for the full Cu-Sn IMCs joint with 46.7 per cent Cu₃Sn, the cleavage fracture happened within the Cu6Sn5. As the Cu₃Sn proportion increased to 60.6 per cent, the inter-granular fracture, which resulted in the interfacial delamination of Cu₃Sn and Cu6Sn5, occurred along the Cu₃Sn/Cu6Sn5 interface, while the cleavage fracture happened within the Cu6Sn5. Then, with the Cu₃Sn proportion increasing to 76.7 per cent, the cleavage fracture happened within the Cu6Sn5, while the transgranular fracture happened within the Cu₃Sn. The inter-granular fracture, which led to the interfacial delamination of Cu₃Sn and Cu, happened along the Cu/Cu₃Sn interface. For the full Cu₃Sn joint, the cleavage fracture happened within the Cu₃Sn.

The shear strength and fracture mechanism of full Cu-Sn IMCs joints was systematically studied. A direct comparison regarding the shear strength and fracture mechanism between the full Cu-Sn IMCs joints and joints with the conventional interfacial structure was conducted.

This paper gives a bibliographical review of the finite element methods (FEMs) applied to the analysis of ceramics and glass materials. The bibliography at the end of the paper contains references to papers, conference proceedings and theses/dissertations on the subject that were published between 1977‐1998. The following topics are included: ceramics – material and mechanical properties in general, ceramic coatings and joining problems, ceramic composites, ferrites, piezoceramics, ceramic tools and machining, material processing simulations, fracture mechanics and damage, applications of ceramic/composites in engineering; glass – material and mechanical properties in general, glass fiber composites, material processing simulations, fracture mechanics and damage, and applications of glasses in engineering.

This paper aims to review recent reports on mechanical properties of Sn-Bi and Sn-Bi-X solders (where X is an additional alloying element), in terms of the tensile properties, hardness and shear strength. Then, the effects of alloying in Sn-Bi solder are compared in terms of the discussed mechanical properties. The fracture morphologies of tensile shear tested solders are also reviewed to correlate the microstructural changes with mechanical properties of Sn-Bi-X solder alloys.

A brief introduction on Sn-Bi solder and reasons to enhance the mechanical properties of Sn-Bi solder. The latest reports on Sn-Bi and Sn-Bi-X solders are combined in the form of tables and figures for each section. The presented data are discussed by comparing the testing method, technical setup, specimen dimension and alloying element weight percentage, which affect the mechanical properties of Sn-Bi solder.

The addition of alloying elements could enhance the tensile properties, hardness and/or shear strength of Sn-Bi solder for low-temperature solder application. Different weight percentage alloying elements affect differently on Sn-Bi solder mechanical properties.

This paper provides a compilation of latest report on tensile properties, hardness, shear strength and deformation of Sn-Bi and Sn-Bi-X solders and the latest trends and in-depth understanding of the effect of alloying elements in Sn-Bi solder mechanical properties.

Au stud bump bonding technology is an effective means to realize heterogeneous integration of commercial chips in the 2.5D electronic packaging. The purpose of this paper is to study the long-term reliability of the Au stud bump treated by four different high temperature storage times (200°C for 0, 100, 200 and 300 h).

The bonding strength and the fracture behavior are investigated by chip shear test. The experiment is further studied by microstructural characterization approaches such as scanning electron microscope, energy dispersive spectrometer and so on.

It is recognized that there were mainly three typical fracture models during the chip shear test among all the Au stud bump samples treated by high temperature storage. For solder bump before aging, the fracture occurred at the interface between the Cu pad and the Au stud bump. As the aging time increased, the fracture mainly occurred inside the Au stud bump at 200°C for 100 and 200 h. When aging time increased to 300 h, it is found that the fracture transferred to the interface between the Au stud bump and the Al Pad.

In addition, the bonding strength also changed with the high temperature storage time increasing. The bonding strength does not change linearly with the high temperature storage time increasing but decreases first and then increases. The investigation shows that the formation of the intermetallic compounds because of the reaction between the Au and Al atoms plays a key role on the bonding strength and fracture behavior variation.

Plastic ball grid array packages were aged for up to 2000 hours. Various solder ball pad metallurgies were studied and solder ball shear tests were conducted at a range of ageing times. The solder ball shear strength was found to decrease after an initial hardening stage. The deterioration of solder ball shear strength was found to be mainly caused by the formation of intermetallic compound layers, together with microstructural coarsening and diffusion related porosity at the interface. For the ball pad metallurgy, two distinct intermetallic compound layer structures were observed to have formed after ageing. Once two continuous intermetallic compound layers formed fracture tended to occur at their interface. For the ball pad metallurgies which do not form two continuous intermetallic compound layers, the shear strength still decreased, due to the coarsening of the microstructure, intermetallic particle formation and diffusion related porosity at the surface of the Ni₃Sn₄.

This paper aims to present the influences of several production variables on the mechanical properties of specimens manufactured using fused deposition modeling (FDM) with polylactic acid (PLA) as a media and relate the practical and experimental implications of these as related to stiffness, strength, ductility and generalized loading.

A two-factor-level Taguchi test matrix was defined to allow streamlined mechanical testing of several different fabrication settings using a reduced array of experiments. Specimens were manufactured and tested according to ASTM E8/D638 and E399/D5045 standards for tensile and fracture testing. After initial analysis of mechanical properties derived from mechanical tests, analysis of variance was used to infer optimized production variables for general use and for application/load-specific instances.

Production variables are determined to yield optimized mechanical properties under tensile and fracture-type loading as related to orientation of loading and fabrication.

The relation of production variables and their interactions and the manner in which they influence mechanical properties provide insight to the feasibility of using FDM for rapid manufacturing of components for experimental, commercial or consumer-level use.

This paper is the first report of research on the characterization of the mechanical properties of PLA coupons manufactured using FDM by the Taguchi method. The investigation is relevant both in commercial and consumer-level aspects, given both the currently increasing utilization of 3D printers for component production and the viability of PLA as a renewable, biocompatible material for use in structural applications.

This paper aims to present a new micro‐impact tester developed for characterizing the impact properties of solder joints and micro‐structures at high‐strain rates, for the microelectronic industry, and the results evaluated for different solder ball materials, pad finishes and thermal histories by using this new tester. Knowledge of impact force is essential for quantifying the strength of the interconnection and allows quantitative design against failure. It also allows one‐to‐one comparison with the failure force measured in a standard quasi‐static shear test.

An innovative micro‐impact head has been designed to precisely strike the specimen at high speed and the force and displacements are measured simultaneously and accurately during the impact, from which the failure energy may be calculated.

The paper demonstrates that, peak loads obtained from the impact tests are between 30 and 100 percent higher than those obtained from static shear tests for all combinations of solder alloy and pad finish. The SnPb solder alloy had the maximum energy to failure for all pad finishes. Of all the lead‐free solders, the SnAg solder alloy had the highest energy to failure. Static shearing induces only bulk solder failure for all combinations of solder alloy and pad finish. Impact testing tends to induce bulk solder failure for SnPb solder and a mixture of bulk and intermetallic failure in all the lead‐free solder alloys for all pad finishes. In general, the peak loads obtained for solder mask defined pads are significantly higher than those for non‐SMD (NSMD) pads. The results obtained so far have highlighted the vulnerability of NSMD pads to drop impact.

The work provides a new solution to the microelectronics industry for characterizing the impact properties of materials and micro‐structures and provides an easy‐to‐use tool for research or process quality control.

The new micro‐impact tester developed is able to perform solder ball shear testing at high speeds, of up to 1,000 mm/s, and to obtain fracture characteristics similar to those found in drop impact testing using the JEDEC board level testing method JESD22‐B111 – but without the complexity of preparing specialized boards. This is not achievable using standard low‐speed shear testers.

Acrylonitrile butadiene styrene (ABS), as a light and high strength thermoplastic polymer, has found extensive applications in different industries. Fused filament fabrication, known as three-dimensional (3D) printing technique is considered a rapid prototyping technique that is frequently applied for production of samples of ABS material. Therefore, the purpose of this study is to investigate the mechanical and fracture behavior of such materials and the techniques to improve such properties.

Experimental and numerical analyses have been conducted to investigate the effects of internal architecture and chopped carbon fiber (CF) fillers on the mechanical properties and mixed mode fracture behavior of the ABS samples made by 3D printing technique. Four different filling types at 70% filling ratios have been used to produce tensile and special fracture test samples with pure and CF filled ABS filaments (CF-ABS) using 3D process. A special fixture has been developed to apply mixed mode loading on fracture samples, and finite element analyses have been conducted to determine the geometric function of such samples at different loading angles.

It has been determined that the printing pattern has a significant effect on the mechanical properties of the sample. The addition of 15% CF to pure ABS resulted in a significant increase in tensile strength of 46.02% for line filling type and 15.04% for hexagon filling type. It has been determined that as the loading angle increases from 0° to 90°, the KIC value decreases. The addition of 15% CF increased the K_IC values for hexagonal and line filling type by 64.14% and 12.5%, respectively.

The damage that will occur in ABS samples produced in 3D printers depends on the type, amount, filling speed, filling type, filling ratio, filling direction and mechanical properties of the additives. All these features are clearly dependent on the production method. Even if the same additive is used, the production method difference shows different microstructural parameters, especially different mechanical properties.

The purpose of this study is to develop an efficient numerical procedure for simulating the effect of printing orientation, as one of the primary sources of anisotropy in 3D-printed components, on their fracture properties.

The extended finite element method and the cohesive zone model (XFEM-CZM) are used to develop subroutines for fracture simulation. The ability of two prevalent models, i.e. the continuous-varying fracture properties (CVF) model and the weak plane model (WPM), and a combination of both models (WPM-CVF) are evaluated to capture fracture behavior of the additively manufactured samples. These models are based on the non-local and local forms of the anisotropic maximum tangential stress criterion. The numerical models are assessed by comparing their results with experimental outcomes of 16 different configurations of polycarbonate samples printed using the material extrusion technique.

The results demonstrate that the CVF exaggerates the level of anisotropy, and the WPM cannot detect the mild anisotropy of 3D-printed parts, while the WPM-CVF produces the best results. Additionally, the non-local scheme outperforms the local approach in terms of finite element analysis performance, such as mesh dependency, robustness, etc.

This paper provides a method for modeling anisotropic fracture in 3D-printed objects. A new damage model based on a combination of two prevalent models is offered. Moreover, the developed subroutines for implementing the non-local anisotropic fracture criterion enable a reliable crack propagation simulation in media with varying degrees of complication, such as anisotropy.

The purpose of this paper is to investigate the effect of layer orientation on the tensile, flexural and fracture behavior of additively manufactured (AM) polycarbonate (PC) produced using fused deposition modeling (FDM).

An experimental approach is undertaken and a total number of 48 tests are conducted. Two types of tensile specimens are used and their mechanical behavior and fracture surfaces are studied. Also, circular parts with different layer orientations are printed and two semi-circular bending (SCB) samples are extracted from each part. Finally, the results of samples with different build directions are compared to one another to better understand the mechanical behavior of additively manufactured PC.

The results demonstrate anisotropy in the tensile, flexural and fracture behavior of the additively manufactured PC parts with the latter being less anisotropic compared to the first two. It is also demonstrated that the anisotropy of the elastic modulus is small and can be neglected. Tensile strength ranges from 40 MPa to 53 MPa. At the end, mode I fracture toughness prediction curves are provided for different directions of the FDM samples. Fracture toughness ranges from 1.93 to 2.37 MPa.mm^1/2.

The SCB specimen, a very suitable geometry for characterizing anisotropic materials, was used to characterize FDM parts for the first time. Also, the fracture properties of the AM PC have not been studied by the researchers in the past. Therefore, fracture toughness prediction curves are presented for this anisotropic material. These curves can be very suitable for designing parts that are going to be produced by 3D printing. Moreover, the effect of the area to perimeter ratio on the tensile properties of the printed parts is investigated.