The Alignment Shift Formation Mechanism of Thin Film Based DWDM Module With Solder Assembly Packaging

2004 ◽  
Vol 126 (3) ◽  
pp. 273-281 ◽  
Author(s):  
Samuel I-En Lin

Thermal residual plastic deformation of bond joints on thin film based DWDM module under thermal cycles loading was investigated using three-dimensional finite element analysis. Finite element simulations were carried out to investigate the effect of the 4 and 6 solder-joint designs for the metal tube with 0.1 mm alignment offset. It was found that 6-solder joint requires more thermal cycles to arrive a stable tilt angle. The transverse movement of metal tube under thermal loading was also examined to determine the influence of solder volume imperfections and solder materials. Favorable results were obtained for 80Au20Sn solder as compared to 63Sn37Pb solder. From the thermal-elasto-plastic analysis, the solder volume control has great impact on the metal tube movement and tilt angle during thermal loadings. If adequate solder volume is provided in four solder joints, the minimum alignment shift of the metal tube is projected to be comparable to an optimally designed bond joint geometry.

2006 ◽  
Vol 306-308 ◽  
pp. 1151-1156 ◽  
Author(s):  
Chong Du Cho ◽  
Heung Shik Lee ◽  
Chang Boo Kim ◽  
Hyeon Gyu Beom

In this paper, a finite element code especially for micro-magnetostrictive actuators was developed. Two significant characteristics of the presented finite element code are: (1) the magnetostrictive hysteresis phenomenon is effectively taken into account; (2) intrinsic geometric feature of typical thin film structures of large length to thickness ratio, which makes it very difficult to construct finite element mesh in the region of the thin film, is considered reasonably in modeling micro-magneostrictive actuators. For verification purpose, magnetostrictive thin films were fabricated and tested in the form of a cantilevered actuator. The Tb-Fe film and Sm-Fe film are sputtered on the Si and Polyimide substrates individually. The magnetic and magnetostrictive properties of the sputtered magnetostrictive films are measured. The measured magnetostrictive coefficients are compared with the numerically calculated ones.


1996 ◽  
Vol 118 (4) ◽  
pp. 206-213 ◽  
Author(s):  
K. X. Hu ◽  
C. P. Yeh ◽  
X. S. Wu ◽  
K. Wyatt

Analysis of interfacial delamination for multichip module thin-film interconnects (MCM/TFI) is the primary objective of this paper. An interface crack model is integrated with finite-element analysis to allow for accurate numerical evaluation of the magnitude and phase angle of the complex stress intensity factor. Under the assumption of quasi-static delamination growth, the fate of an interfacial delamination after inception of propagation is determined. It is established that whether an interfacial delamination will continue to grow or become arrested depends on the functional behavior of the energy release rate and loading phase angle over the history of delamination growth. This functional behavior is numerically obtained for a typical MCM/TFI structure with delamination along die and via base, subjected to thermal loading condition. The effect of delamination interactions on the structural reliability is also investigated. It is observed that the delamination along via wall and polymer thin film can provide a benevolent mechanism to relieve thermal constraints, leading to via stress relaxation.


Author(s):  
Sayed A. Nassar ◽  
Amir Kazemi

Experimental and finite element techniques are used for investigating the effect of cyclic thermal loading on the clamp load decay in preloaded single-lap bolted joints that are made of multimaterial lightweight alloys. Substrate material combinations include aluminum, magnesium, and steel, with various coupon thicknesses. The range of cyclic temperature profile varies between −20 °C and +150 °C in a computer-controlled environmental chamber for generating the desired cyclic temperature profile and durations. Real time clamp load data are recorded using strain gage-based, high-temperature, load cells. Clamp load decay is investigated for various combinations of joint materials, initial preload level, and substrate thickness. Thermal and material creep finite element analysis (FEA) is performed using temperature-dependent mechanical properties. The FEA model and results provided a valuable insight into the experimental results regarding the vulnerability of some lightweight materials to significant material creep at higher temperatures.


1999 ◽  
Author(s):  
Stephen A. McKeown ◽  
Chittaranjan Sahay

Abstract Paper describes the effect of solder volume on solder life based on linear finite element analysis using ANSYS. The results indicate an optimal volume for the solder life. Any increase or decrease in the solder volume from the optimum volume decreases the fatigue life of solder joints. Solder joint life was also experimentally determined for the same temperature excursion with a 2-hour thermal cycle. The experimental results compare well with the results estimated by finite element modeling. Studies for one elastic-plastic analysis has also been carried out. Initial results indicate substantial increase in strain concentration factor.


Author(s):  
Shunji Kataoka ◽  
Takuya Sato

Creep-fatigue damage is one of the dominant failure modes for pressure vessels and piping used at elevated temperatures. In the design of these components the inelastic behavior should be estimated accurately. An inelastic finite element analysis is sometimes employed to predict the creep behavior. However, this analysis needs complicated procedures and many data that depend on the material. Therefore the design is often based on a simplified inelastic analysis based on the elastic analysis result, as described in current design codes. A new, simplified method, named, Stress Redistribution Locus (SRL) method, was proposed in order to simplify the analysis procedure and obtain reasonable results. This method utilizes a unique estimation curve in a normalized stress-strain diagram which can be drawn regardless of the magnitude of thermal loading and constitutive equations of the materials. However, the mechanism of SRL has not been fully investigated. This paper presents results of the parametric inelastic finite element analyses performed in order to investigate the mechanism of SRL around a structural discontinuity, like a shell-skirt intersection, subjected to combined secondary bending stress and peak stress. This investigation showed that SRL comprises a redistribution of the peak and secondary stress components and that although these two components exhibit independent redistribution behavior, they are related to each other.


Author(s):  
Tz-Cheng Chiu ◽  
Huang-Chun Lin

The interface crack problem in integrated circuit devices was considered by using global and local modeling approach. In the global analysis the thin film interconnect was modeled by a homogenized layer with material constants obtained from representative volume element (RVE) analysis. Local analyses were then considered to determine fracture mechanics parameters. It was shown that the multiscale model with RVE approach gives accurate fracture mechanics parameters for an interface crack under either thermal or mechanical loads; while significant error was observed when the thin film layers are ignored in the global analysis. The problem of an interface crack between low-k dielectric and etch-stop thin film in a flip-chip package under thermal loading was also investigated as an application example of the multiscale modeling.


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