scholarly journals Evaluation of Fracture Toughness of TiN Thin Film on Cemented Carbide by the Sphere Indentation Testing

2009 ◽  
Vol 75 (757) ◽  
pp. 1165-1170
Author(s):  
Tohru TAKAMATSU ◽  
Hirotaka TANABE ◽  
Koji MIYAHARA
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Cemented Carbide ◽  
Indentation Testing

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

On the Interaction Between Indentation Cracks on Metallized Silicon

1998 ◽  
Vol 516 ◽  
Author(s):  
M. Manoharan ◽  
G. Muralidharan
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Bulk Material ◽  
Small Sample Size ◽  
Industrial Process ◽  
Crack Size ◽  
Small Sample ◽  
Residual Stress Field ◽  
Metallization Layer ◽  
Free Material

AbstractThe metallization of Si represents a important industrial process and produces a bi-layered composite of a ductile metal film on a brittle substrate. The mechanical properties of such a composite are determined by the properties of the two layers and the interface and influenced by the fact that the metallized layer, being a very thin film, possesses properties different from those of a bulk material. The fracture toughness is also influenced by the nature and distribution of defects which may be generated during use of these materials, even if the manufacturing process produces a reasonably defect free material. Indentation cracking has been extensively used for the measurement of fracture toughness due to its small sample size requirements as well as a relatively good correlation with values obtained from traditional fracture mechanics tests. The indentation process, with its associated cracks, produces permanent plastic deformation and also introduces a residual stress field. This field influences the crack pattern generated in an adjacent indent and can be used as a methodology to model the influence of multiple defect sources.The present study was aimed at understanding the effect of a thin Ti alloy metallization layer sputtered on a Si wafer on the sizes of the cracks associated with the indents. It was also aimed at studying the interaction between cracks emanating from sequentially placed indentations. The distance between the indents which generated these cracks was varied from a level comparable to the crack size to a level where interaction could be ignored. This paper discusses the changes in the nature as well as the sizes of cracks due to the presence of the metallization layer as well as the interaction between the stress fields of the indents in this ductile thin film – brittle substrate composite and possible methodologies for delineating these effects.

Characterization of Bulk and Thin Film Fracture in Electronic Packaging

2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Vijay Subramanian ◽  
Kyle Yazzie ◽  
Tsgereda Alazar ◽  
Bharat Penmecha ◽  
Pilin Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Electronic Packaging ◽  
Low Cost ◽  
Form Factors ◽  
Test Methods ◽  
Thin Layers ◽  
Filler Materials ◽  
Fracture Characterization ◽  
Environmental Testing

As semiconductor packaging technologies continue to scale, it drives the use of existing and new materials in thin layer form factors. Increasing packaging complexity implies that materials in thin layers are subject to nontrivial loading conditions, which may exceed the toughness of the material, leading to cracks. It is important to ensure that the reliability of these low-cost materials is at par or better than currently used materials. This in turn leads to significant efforts in the area of material characterization at the lab level to speed up the development process. Methods for testing and characterizing fracture-induced failures in various material systems in electronic packaging are investigated in this paper. The learnings from different test methods are compared and discussed here. More specifically, different fracture characterization techniques on (a) freestanding “thin” solder-resist films and (b) filled “bulk” epoxy materials such as underfills and epoxy mold compounds are investigated. For thin films, learnings from different test methods for measuring fracture toughness, namely, uniaxial tension (with and without an edge precrack) and membrane penetration tests, are discussed. Reasonably good agreement is found between the various thin film toughness test methods; however, ease of sample preparation, fixture, and adaptability to environmental testing will be discussed. In the case of filled epoxy resin systems, the single-edge-notched bending (SENB) technique is utilized to obtain the fracture toughness of underfills and mold compounds with filler materials. Learnings on different methods of creating precracks in SENB samples are also investigated and presented.

Modified Decohesion Test (MDT) for Interfacial Fracture Toughness Measurement in Microelectronic/MEMS Applications

2002 ◽  
Author(s):  
Mitul B. Modi ◽  
Suresh K. Sitaraman
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Fracture Toughness ◽  
Energy Release ◽  
Physical Vapor Deposition ◽  
Interfacial Fracture ◽  
Interfacial Fracture Toughness ◽  
Testing Methods ◽  
Structural Variations ◽  
Metal Thin Film

Delamination of intrinsically or residually stressed thin films is commonly encountered in microelectronics and MEMS systems. Thin films typically accrue stresses through micro structural variations caused by physical vapor deposition, thermally induced stresses imposed due to thermal mismatch, and/or extrinsically introduced forces. These stresses can reach upwards of 1 GPa and can easily exceed the strength of the metal thin film interface. Knowledge of the interfacial fracture toughness (Γ) is necessary to predict if delamination will occur. However, measuring Γ is a challenge for thin film interfaces. Typical testing methods such as bimaterial cantilever, microscratch, peel, bulge, or edge lift-off are limited to organic films, cause complex stress fields, can only measure a single mode mix, or cannot achieve the large energy release rates typical of metal thin film interfaces. A new approach based on the decohesion test, called the modified decohesion test (MDT), eliminates these shortcomings of current testing methods. In this approach, a highly stressed super layer is used to drive delamination and “tune-in” the mode mix at the crack tip. Since the deformations remain elastic, a mechanics-based solution can be used to correlate test parameters to the energy release rate. Common IC fabrication techniques are used to prepare the sample and execute the test, thereby making the test compatible with current microelectronic or MEMS facilities. Varying the crack surface area rather than the energy in the super layer allows the ability to bound Γ using a single test wafer providing a 90% savings in resources and 95% savings in time. Other modifications allow application of the method to highly chemically reactive metals and decrease the sample preparation time. Design, preparation, and execution of the MDT are presented. Results of finite element models are used to validate the approach. Results are shown for a Ti/Al2O3 interface.

An Innovative Technique for Bi-Material Interface Toughness Research

2004 ◽  
Author(s):  
John Jy-An Wang ◽  
Ian G. Wright ◽  
Ken C. Liu ◽  
Roy L. Xu
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Fracture Mechanics ◽  
Coefficient Of Thermal Expansion ◽  
Testing Procedure ◽  
Interface Fracture ◽  
Fracture Toughness Test ◽  
Coating Materials ◽  
Testing Procedures ◽  
Interface Fracture Toughness

A material configuration of central importance in microelectronics, optoelectronics, and thermal barrier coating technology is a thin film of one material deposited onto a substrate of a different material. Fabrication of such a structure inevitably gives rise to stress in the film due to lattice mismatch, differing coefficient of thermal expansion, chemical reactions, or other physical effects. Therefore, in general, the weakest link in this composite system often resides at the interface between the thin film and substrate. In order to make multi-layered electronic devices and structural composites with long-term reliability, the fracture behavior of the material interfaces must be known. Unfortunately, none of the state-of-the-art testing methods for evaluating interface fracture toughness is fully conformed to fracture mechanics theory, as is evident from the severe scatter in the existing data, and the procedure dependence in thin film/coating evaluation methods. This project is intended to address the problems associated with this deficiency and offers an innovative testing procedure for the determination of interface fracture toughness applicable to thin coating materials in general. Phase I of this new approach and the associated bi-material fracture mechanics development proposed for evaluating interface fracture toughness are described herein. The effort includes development of specimen configuration and related instrumentation set-up, testing procedures, and postmortem examination. A spiral notch torsion fracture toughness test (SNTT) system was utilized. The objectives of the testing procedure described are to enable the development of new coating materials by providing a reliable method for use in assessing their performance.

Superlayer Test for Interfacial Fracture Toughness Measurements

2004 ◽  
Author(s):  
Jiantao Zheng ◽  
Suresh K. Sitaraman
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Interfacial Fracture ◽  
Critical Energy ◽  
Interfacial Fracture Toughness ◽  
Mode Mixity ◽  
Critical Energy Release Rate ◽  
Component Reliability ◽  
Interfacial Delamination ◽  
Interface Delamination

Knowledge of the mode-mixity (?) dependent interfacial fracture toughness (Γ) is needed to predict the interface delamination and the component reliability of thin-film structures. Mode-mixity, ?, is a measure of the relative shearing to tensile opening of the interface crack near the tip. Typically, Γ increases as ? increases, such that the delamination is less likely when the loading on the interface is shear-dominated. The measurement of mode-mixity dependent Γ has been a challenge for thin film interfaces. The single-strip superlayer test, developed by the authors, eliminates the shortcomings of current testing methods. This test employs a stress-engineered superlayer to drive the interfacial delamination between the thin-film and the substrate. An innovative aspect of the proposed test is to introduce a release layer of varying width between the interested interfaces to control the amount of energy available for delamination propagation. By designing a decreasing area of the release layer, it is possible to arrest the interfacial delamination at a given location, and the interfacial fracture toughness or critical energy release rate can be found at the location where the delamination ceases to propagate. Design, preparation, and execution of the test are presented. Results are shown for Ti/Si interfaces of different mode mixities.

Fracture Toughness of Titanium - Titanium Nitride Multi-Layer Thin Film

2008 ◽  
Author(s):  
Mohan Prasad Manoharan ◽  
Amit Desai ◽  
Amanul Haque
Keyword(s):  
Thin Film ◽  
Fracture Toughness ◽  
Titanium Nitride ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
New Class ◽  
Tin Coatings ◽  
Film Specimen ◽  
Cantilever Bending ◽  
Layer Thin Film

Thin film specimens of titanium - titanium nitride multilayer erosion resistant coating were prepared using liftout technique in Focused Ion Beam - Scanning Electron Microscope (SEM). The fracture toughness of the thin film specimen was measured in situ using a cantilever bending experiment in SEM to be 11.33 MPa/m0.5, twice as much as conventional TiN coatings. Ti–TiN multi-layer coatings are part of a new class of advanced erosion resistant coatings and this paper discusses an experimental technique to measure the fracture toughness of these coatings.

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