Open Access Original Research Article

Semiconductor QFN Package with Advanced Interlocking Design

Rennier Rodriguez, Frederick Ray Gomez

Journal of Engineering Research and Reports, Page 1-6
DOI: 10.9734/jerr/2020/v12i117069

The mechanical interlocking structure for quad-flat no-lead (QFN) assembly for densified leadframe degrades as the package becomes thinner. Detractors such as package reliability and design requirement hinder further qualification of leadframes with increased number of input/output (I/O) pins. In this paper, a new and advanced design of leadframe is discussed and presented with improvement in mechanical interlocking structure of high stress areas such as lead and pad junction. The leadframe is re-designed having lead lines on the lead and pad that will be etched away after molding process replacing full copper base frame. Through application of the design, the effective mechanical interlocking is improved from 60% to 100% for mold-lead and mold-pad interface.

Open Access Original Research Article

Influence of Various Types of Steel Fibre on the Mechanical and Physical Characteristics of GGBS Based Geopolymer Concrete

M. Ali Sadawy, Ahmed Serag Faried, H. A. El-Ghazaly

Journal of Engineering Research and Reports, Page 7-19
DOI: 10.9734/jerr/2020/v12i117070

This study provides experimental investigation of the mechanical and physical properties of reinforced geopolymer concrete based on Ground Granulated Blast Furnace Slag (GGBS). This research demonstrates the influence of various types of steel fibre on compressive, split tensile, flexural strengths and elastic modulus of hardened GPC, workability of reinforced geopolymer concrete and also analyzed the workability, setting time and flow test of fresh geopolymer concrete. Additionally, corrosion test was conducted on reinforced geopolymer concrete. Mixtures of alkaline liquid to GGBS ratio of 0.5 with steel fibers had been added to the mixture of 0% volume fractions (Vf %), 0.5%, 1.0%, and 1.5% concrete amount. Based on the result of the experiments, the presence of steel fibres enhanced the compressive and tensile strength of the SERGPC, in terms of volume fraction of steel fibres as compared to the regular GPC without fibres. It was observed that there was a significant improvement in GPC's mechanical characteristics and corrosion rate as the lifespan of concrete increased. The incorporation of steel fibres resulted in increased compressive and flexural strengths in the early age and consequently tensile splitting power was increased. The increase in concrete geopolymer content improved the rate of corrosion over time.

Open Access Original Research Article

Improved Chuck Table Design for Silicon Wafer Defects Resolution

Bryan Christian Bacquian, Frederick Ray Gomez

Journal of Engineering Research and Reports, Page 20-24
DOI: 10.9734/jerr/2020/v12i117071

The paper aimed to mitigate wafer defects such as large kerf shifting issue, dice pop-out occurrence and edge cut defects in the wafer preparation or pre-assembly stage of integrated circuits (IC) assembly manufacturing. With the introduction of new wafer preparation technologies such as dicing before grinding (DBG) and laser die attach film (DAF) cut, technical challenges were encountered. The paper focused on the interaction of different glass chuck table design and laser DAF parameter in order to address the problems. Based on the evaluation and revalidation of results, it has been identified that the single hole without outer groove glass chuck table design improved the response, eliminating dice pop-out issue at laser DAF cut, as well as the kerf shifting issue and edge cut defect.

Open Access Original Research Article

Comparison of Regression Model Concepts for Estimating Traffic Noise

Amah, Victor Emeka, Atuboyedia, Tam-Jones

Journal of Engineering Research and Reports, Page 25-32
DOI: 10.9734/jerr/2020/v12i117072

Traffic noise at two locations which are Rumuokoro and Rumuola in Port Harcourt city, Rivers state Nigeria was studied. The study was done for 3 days at each location. Variables such as atmospheric parameters and traffic density were measured along with the noise measurement. The atmospheric parameters measured were temperature, relative humidity and wind speed. Traffic density includes number of small cars and trucks per 20m radius. Three empirical model concepts were proposed, calibrated using multiple regression analysis and validated by cross validation and coefficient of determination (R2). The models are a linear model, a polynomial model and an exponential model. The coefficient of determination for the linear model ranged from 0.25 to 0.94 at Rumuokoro and 0.29 to 0.86 at Rumuola. The coefficient of correlation for the polynomial model ranged from 0.062 to 0.998 at Rumuokoro and 0.05 to 0.998 at Rumuola. The coefficient of correlation for the exponential model ranged from 0.28 to 0.92 at Rumuokoro and 0.45 to 0.89 at Rumuola. The exponential model was concluded to be the best model concept because of its performance in predicting noise levels using data from other days with moderately high and consistent coefficient of determination at both locations. However, if extrapolation is not to be considered, the polynomial model concept is very useful.

Open Access Original Research Article

Wirebond Process Improvement through Silicon Die Polyimide Removal

Anthony R. Moreno, Jonalyn E. Jaylo, Frederick Ray I. Gomez, Edwin M. . Graycochea Jr

Journal of Engineering Research and Reports, Page 33-37
DOI: 10.9734/jerr/2020/v12i117073

This study aims to develop polyimide etching process on the silicon die after decapsulation to resolve the wire shear issue during ball shear data gatherings. The shear strength of the ball is affected by the presence of polyimide insulator during ball shearing process, due to the polyimide layer of the silicon die being coplanar with the ball height of the wire. Experimentation and statistical analysis were done on units with and without polyimide coating, with Sodium Hydroxide (NaOH) used to remove the excess polyimide.  Results revealed that silicon dice without polyimide coating resulted to better reading in terms of ball shear.