Material Interaction Effects in the Reliability of High Density Interconnect (HDI) Boards

2003 ◽  
Author(s):  
Saketh Mahalingam ◽  
Shashikant Hegde ◽  
Gnyaneshwar Ramakrishna ◽  
Raghuram V. Pucha ◽  
Suresh K. Sitaraman
Keyword(s):  
Computational Algorithm ◽  
Optimization Technique ◽  
Simulation Models ◽  
Dielectric Materials ◽  
Interaction Effects ◽  
High Density ◽  
Interlayer Dielectric ◽  
Gradient Based ◽  
Material Interaction ◽  
Base Substrate

This paper studies several base substrate materials and interlayer dielectric materials for High Density Interconnect (HDI) boards, addressing reliability issues such as warpage, dielectric cracking and microvia cracking. Design of simulation models with an optimization technique is developed to study material interaction effects on the HDI reliability. A plastic strain gradient-based computational algorithm is developed to study the thermo-mechanical deformation of fine-feature microvia structures.

Enhanced Reliability of High Density Wiring (HDW) Substrates Through New Dielectric and Base Substrate Materials

2002 ◽  
Author(s):  
Shashikant Hegde ◽  
Raghuram V. Pucha ◽  
Suresh K. Sitaraman
Keyword(s):  
Flip Chip ◽  
Failure Modes ◽  
Element Model ◽  
Dielectric Materials ◽  
High Density ◽  
Operating Conditions ◽  
High Modulus ◽  
Interlayer Dielectric ◽  
Board Material ◽  
Base Substrate

FR4 has been extensively used as a board material due to its cost effectiveness and overall performance. For high-density wiring (HDW) substrates with microvias and with embedded capacitors, inductors, resistors, RF and optoelectronic waveguides in a single board, there is a need for alternative base substrates to meet the stringent warpage requirements during fabrication. Typically, these base substrate materials should have high modulus, good planarity, in addition to having a CTE that is close to that of silicon so that the flip-chips can be directly attached to the substrate, eliminating the need for an underfill. Although low-CTE, high modulus base substrate materials can eliminate the need for underfill as well as can result in less warpage during fabrication, they can potentially cause delamination and cracking in the interlayer dielectric. This is due to the high CTE mismatch between the base substrate and typical polymer dielectric. This paper aims to explore a combination of base substrate materials and interlayer dielectric materials such that warpage is minimal, dielectric will not crack or delaminate, and flip-chip solder joints, assembled without an underfill, will not crack prematurely during qualification regimes and operating conditions. A non-liner finite element model with Design-of-Simulations approach is used in arriving at optimized thermo-mechanical properties for the base-substrate and dielectric materials to enhance the overall reliability of the integrated substrate with flip chip assembly. The results from the models have been compared with experimental data and a discussion is presented on the various failure modes.

scholarly journals A modified simplex based direct search optimization algorithm for adaptive transversal FIR filters

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110254
Author(s):  
Armaghan Mohsin ◽  
Yazan Alsmadi ◽  
Ali Arshad Uppal ◽  
Sardar Muhammad Gulfam
Keyword(s):  
Optimization Algorithm ◽  
Optimization Technique ◽  
Fast Convergence ◽  
Good Convergence ◽  
Optimum Point ◽  
Search Optimization ◽  
Higher Dimensional ◽  
Gradient Based ◽  
Improved Accuracy ◽  
Quadratic Cost Function

In this paper, a novel modified optimization algorithm is presented, which combines Nelder-Mead (NM) method with a gradient-based approach. The well-known Nelder Mead optimization technique is widely used but it suffers from convergence issues in higher dimensional complex problems. Unlike the NM, in this proposed technique we have focused on two issues of the NM approach, one is shape of the simplex which is reshaped at each iteration according to the objective function, so we used a fixed shape of the simplex and we regenerate the simplex at each iteration and the second issue is related to reflection and expansion steps of the NM technique in each iteration, NM used fixed value of [Formula: see text], that is, [Formula: see text]  = 1 for reflection and [Formula: see text]  = 2 for expansion and replace the worst point of the simplex with that new point in each iteration. In this way NM search the optimum point. In proposed algorithm the optimum value of the parameter [Formula: see text] is computed and then centroid of new simplex is originated at this optimum point and regenerate the simplex with this centroid in each iteration that optimum value of [Formula: see text] will ensure the fast convergence of the proposed technique. The proposed algorithm has been applied to the real time implementation of the transversal adaptive filter. The application used to demonstrate the performance of the proposed technique is a well-known convex optimization problem having quadratic cost function, and results show that the proposed technique shows fast convergence than the Nelder-Mead method for lower dimension problems and the proposed technique has also good convergence for higher dimensions, that is, for higher filter taps problem. The proposed technique has also been compared with stochastic techniques like LMS and NLMS (benchmark) techniques. The proposed technique shows good results against LMS. The comparison shows that the modified algorithm guarantees quite acceptable convergence with improved accuracy for higher dimensional identification problems.

Efficient Structural Design Using a Numerical Optimization Technique

2019 ◽  
Author(s):  
Qian Wang ◽  
Lucas Schmotzer ◽  
Yongwook Kim
Keyword(s):  
Structural Design ◽  
Numerical Optimization ◽  
Optimization Technique ◽  
Optimization Method ◽  
Optimization Techniques ◽  
Convergence Criteria ◽  
Efficient Design ◽  
Concrete Building ◽  
Gradient Based ◽  
Structural Responses

<p>Structural designs of complex buildings and infrastructures have long been based on engineering experience and a trial-and-error approach. The structural performance is checked each time when a design is determined. An alternative strategy based on numerical optimization techniques can provide engineers an effective and efficient design approach. To achieve an optimal design, a finite element (FE) program is employed to calculate structural responses including forces and deformations. A gradient-based or gradient-free optimization method can be integrated with the FE program to guide the design iterations, until certain convergence criteria are met. Due to the iterative nature of the numerical optimization, a user programming is required to repeatedly access and modify input data and to collect output data of the FE program. In this study, an approximation method was developed so that the structural responses could be expressed as approximate functions, and that the accuracy of the functions could be adaptively improved. In the method, the FE program was not required to be directly looped in the optimization iterations. As a practical illustrative example, a 3D reinforced concrete building structure was optimized. The proposed method worked very well and optimal designs were found to reduce the torsional responses of the building.</p>

Combined Manufacture Methods for High Density LTCC Substrates: Thick Film Screen Printing, Ink Jet, Postfiring Thin Film Processes, and Laser-Drilled Fine Vias

2009 ◽  
Vol 6 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Arne Albertsen ◽  
Koji Koiwai ◽  
Kyoji Kobayashi ◽  
Tomonori Oguchi ◽  
Katsumi Aruga
Keyword(s):  
Thin Film ◽  
Thick Film ◽  
Screen Printing ◽  
Flip Chip ◽  
High Density ◽  
Uv Laser ◽  
Fine Pitch ◽  
Ink Jet ◽  
Printing Ink ◽  
Base Substrate

This paper highlights the possible combination of technologies such as thick film screen printing, ink jet, and post-firing thin film processes in conjunction with laser-drilled fine vias to produce high-density, miniaturized LTCC substrates. To obtain the silver pattern on the inner layers, both conventional thick film printing and ink jet printing (using nano silver particle dispersed ink) were applied on the ceramic green sheets. The ink jet process made it possible to metallize fine lines with line/space = 30/30 μm. For interlayer connections, fine vias of 30 μm in diameter formed by UV laser were used. Then these sheets were stacked on top of each other and fired to obtain a base substrate. On this base substrate, fine copper patterns for flip chip mounting were formed by a thin film process. The surface finish consisted of a nickel passivation and a gold layer deposited by electroless plating. The combination of the three patterning processes for conducting traces and UV laser drilling of fine vias make it appear possible to realize fine pitch LTCC, for example, for flip chip device mounting.

Intrinsic low dielectric behaviour of a highly thermally stable Sr-based metal–organic framework for interlayer dielectric materials

2014 ◽  
Vol 2 (19) ◽  
pp. 3762-3768 ◽  
Author(s):  
Muhammad Usman ◽  
Cheng-Hua Lee ◽  
Dung-Shing Hung ◽  
Shang-Fan Lee ◽  
Chih-Chieh Wang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Metal Organic Framework ◽  
Dielectric Materials ◽  
Low Dielectric Constant ◽  
Water Molecules ◽  
Compound A ◽  
Interlayer Dielectric ◽  
Low Dielectric ◽  
Metal Organic ◽  
Organic Framework

A Sr-based metal–organic framework exhibits an intrinsic low dielectric constant after removing the water molecules. A low dielectric constant and high thermal stability make this compound a candidate for use as a low-k material.

Optimization of Smart Wells in the St. Joseph Field

2010 ◽  
Vol 13 (04) ◽  
pp. 588-595 ◽  
Author(s):  
G. M. van Essen ◽  
J. D. Jansen ◽  
D. R. Brouwer ◽  
S. G. Douma ◽  
M. J. Zandvliet ◽  
...  
Keyword(s):  
Optimization Technique ◽  
Gas Injection ◽  
Optimal Number ◽  
Control Parameters ◽  
Operational Strategies ◽  
Sector Model ◽  
Optimization Study ◽  
Smart Wells ◽  
Gradient Based ◽  
Reservoir Simulator

Summary The St. Joseph field has been on production since September 1981 under natural depletion supported by crestal gas injection. As part of a major redevelopment study, the scope for waterflooding was addressed using "smart" completions with multiple inflow control valves (ICVs) in the wells to be drilled for the redevelopment. Optimal control theory was used to optimize monetary value over the remaining producing life of the field, and in particular to select the optimal number of ICVs, the optimal configuration of the perforation zones, and the optimal operational strategies for the ICVs. A gradient-based optimization technique was implemented in a reservoir simulator equipped with the adjoint functionality to compute gradients of an objective function with respect to control parameters. For computational reasons, an initial optimization study was performed on a sector model, which showed promising results.

Designing Ultra Low-k Dielectric Materials for Ease of Patterning

2010 ◽  
Vol 1249 ◽  
Author(s):  
George Andrew Antonelli ◽  
Gengwei Jiang ◽  
Mandyam Sriram ◽  
Kaushik Chattopadhyay ◽  
Wei Guo ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ion Beam ◽  
Plasma Reactor ◽  
Dielectric Materials ◽  
Dielectric Constants ◽  
Interlayer Dielectric ◽  
Inductively Coupled ◽  
Inductively Coupled Plasma Reactor ◽  
Low K

AbstractOrganosilicate materials with dielectric constants (k) ranging from 3.0 to 2.2 are in production or under development for use as interlayer dielectric materials in advanced interconnect logic technology. The dielectric constant of these materials is lowered through the addition of porosity which lowers the film density, making the patterning of these materials difficult. The etching kinetics and surface roughening of a series of low-k dielectric materials with varying porosity and composition were investigated as a function of ion beam angle in a 7% C4F8/Ar chemistry in an inductively-coupled plasma reactor. A similar set of low-k samples were patterned in a single damascene scheme. With a basic understanding of the etching process, we will show that it is possible to proactively design a low-k material that is optimized for a given patterning. A case study will be used to illustrate this point.

Interaction effects in high density magnetic particulate media

2004 ◽  
Vol 343 (1-4) ◽  
pp. 48-52 ◽  
Author(s):  
Mihai Cerchez ◽  
Laurentiu Stoleriu ◽  
Alexandru Stancu
Keyword(s):  
Interaction Effects ◽  
High Density ◽  
Particulate Media
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