Creep Prediction of a Printed Wiring Board For Separable Land Grid Array Connector

2004 ◽  
Vol 127 (2) ◽  
pp. 185-188
Author(s):  
J. Cepeda-Rizo ◽  
Hsien-Yang Yeh

The paper presents a study of creep behavior of a printed wiring board caused by the mechanical fastening of separable connector, known as a land grid array. Time-temperature superposition method was employed to predict the lifetime creep behavior. A low-cost testing method based on the ASTM D790 three-point bending procedure was developed to predict and characterize creep of polymeric materials under low temperature, low stress, and large elapsed times.

MRS Bulletin ◽  
2006 ◽  
Vol 31 (6) ◽  
pp. 471-475 ◽  
Author(s):  
Marc Chason ◽  
Daniel R. Gamota ◽  
Paul W. Brazis ◽  
Krishna Kalyanasundaram ◽  
Jie Zhang ◽  
...  

AbstractDevelopments originally targeted toward economical manufacturing of telecommunications products have planted the seeds for new opportunities such as low-cost, large-area electronics based on printing technologies. Organic-based materials systems for printed wiring board (PWB) construction have opened up unique opportunities for materials research in the fabrication of modular electronic systems.The realization of successful consumer products has been driven by materials developments that expand PWB functionality through embedded passive components, novel MEMS structures (e.g., meso-MEMS, in which the PWB-based structures are at the milliscale instead of the microscale), and microfluidics within the PWB. Furthermore, materials research is opening up a new world of printed electronics technology, where active devices are being realized through the convergence of printing technologies and microelectronics.


2004 ◽  
Vol 127 (2) ◽  
pp. 178-184 ◽  
Author(s):  
J. Cepeda-Rizo ◽  
Hsien-Yang Yeh ◽  
N. Teneketges

The paper presents a study on printed wiring board (PWB) warpage caused by the mechanical fastening of separable interconnects, known as land grid array (LGA) package assemblies. Out-of-plane displacement of the PWB were measured and characterized, as well as force-per-pin values of the LGA, and correlations were made between the two. Classical laminate theory was utilized to describe the warpage behavior of the assembly and a model was presented to solve the out-of-plane displacements. An overall assessment of the assembly was made and compared to the mechanical specification of the LGA.


1993 ◽  
Vol 8 (7) ◽  
pp. 527-531
Author(s):  
Satoshi FUJIKI ◽  
Katsumi TANINO ◽  
Yutaka MAKINO ◽  
Kouichi WAKASHIMA

2013 ◽  
Vol 2013 (1) ◽  
pp. 000825-000830 ◽  
Author(s):  
Yoichiro Sato ◽  
Bruce Chou ◽  
Vijay Sukumaran ◽  
Junki Min ◽  
Motoshi Ono ◽  
...  

3D Integrated Passive and Actives Component (IPAC) is a new concept of ultra-miniaturized and highly functional sub-systems, which enables one to achieve higher RF functionality in a single module. As the first step, this paper demonstrates the concept of integrating passive components using 100μm ultra-thin glass and small Through Package Vias (TPVs) by ArF excimer laser. Passive low pass filters (LPF) for WLAN in thin dielectrics on glass were designed using circuit simulator and EM solver. The LPFs were fabricated using low-cost panel based processes, and then assembled onto the Printed Wiring Board (PWB). The filters on either side of the glass interposer were measured at the board level, and the results corroborated well with EM simulations. The measurement results showed low insertion loss (about −1dB) and high rejection (<−20dB). The integration of passive components using double-side and ultra-thin glass interposers with small TPVs, enables one to shrink RF module size.


2013 ◽  
Vol 2 (1) ◽  
pp. 26-30
Author(s):  
Akihiko HAPPOYA ◽  
Sadahiro TAMAI ◽  
Robert HUANG ◽  
Stephen WANG ◽  
Paul LEE ◽  
...  

2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1178
Author(s):  
Aggelos Koutsomichalis ◽  
Thomas Kalampoukas ◽  
Dionysios E. Mouzakis

The purpose of this study was to manufacture hybrid composites from fabrics with superior ballistic performance, and to analyze their viscoelastic and mechanical response. Therefore, composites in hybrid lay-up modes were manufactured from Vectran, Kevlar and aluminum fiber-woven fabrics through a vacuum assisted resin transfer molding. The specimens were consequently analyzed using static three-point bending, as well as by dynamic mechanical analysis (DMA). Apart from DMA, time–temperature superposition (TTS) analysis was performed by all available models. It was possible to study the intrinsic viscoelastic behavior of hybrid ballistic laminates, with TTS analysis gained from creep testing. A polynomic mathematical function was proposed to provide a high accuracy for TTS curves, when shifting out of the linearity regimes is required. The usual Williams–Landel–Ferry and Arrhenius models proved not useful in order to describe and model the shift factors of the acquired curves. In terms of static results, the highly nonlinear stress–strain curve of both composites was obvious, whereas the differential mechanism of failure in relation to stress absorption, at each stage of deformation, was studied. SEM fractography revealed that hybrid specimens with Kevlar plies are prone to tensile side failure, whereas the hybrid specimens with Vectran plies exhibited high performance on the tensile side of the specimens in three-point bending, leading to compressive failure owing to the high stress retained at higher strains after the maximum bending strength was reached.


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