Three-Dimensional Paddle Shift Modeling for IC Packaging

2004 ◽  
Vol 127 (3) ◽  
pp. 324-334 ◽  
Author(s):  
Chien-Chang Pei ◽  
Sheng-Jye Hwang
Keyword(s):  
Structural Analysis ◽  
Integrated Circuits ◽  
Three Dimensional ◽  
Void Formation ◽  
Model Performance ◽  
Computational Time ◽  
Pressure Loading ◽  
Filling Process ◽  
Molding Process ◽  
Incomplete Filling

The plastic packaging process for integrated circuits is subject to several fabrication defects. For packages containing leadframes, three major defects may occur in the molding process alone, namely, incomplete filling and void formation, wire sweep, and paddle shift. Paddle shift is the deflection of the leadframe pad and die. Excessive paddle shift reduces the encapsulation protection for the components and may result in failures due to excessive wire sweep. Computer-aided analysis is one of the tools that could be used to simulate and predict the occurrence of such molding-process-induced defects, even prior to the commencement of mass production of a component. This paper presents a methodology for computational modeling and prediction of paddle shift during the molding process. The methodology is based on modeling the flow of the polymer melt around the leadframe and paddle during the filling process, and extracting the pressure loading induced by the flow on the paddle. The pressure loading at different times during the filling process is then supplied to a three-dimensional, static, structural analysis module to determine the corresponding paddle deflections at those times. The paper outlines the procedures used to define the relevant geometries and to generate the meshes in the “fluid” and “structural” subdomains, and to ensure the compatibility of these meshes for the transfer of pressure loadings. Results are shown for a full paddle shift simulation. The effect on the overall model performance of different element types for the mold-filling analysis and the structural analysis is also investigated and discussed. In order to obtain more accurate results and in a shorter computational time for the combined (fluid and structural) paddle shift analysis, it was found that higher-order elements, such as hexahedra or prisms, are more suitable than tetrahedra.

Study of Different Dispensing Patterns of No-Flow Underfill Using Numerical and Experimental Methods

2020 ◽  
Author(s):  
Muhammad Naqib Nashrudin ◽  
Mohamad Aizat Abas ◽  
Mohd Z. Abdullah ◽  
M. Yusuf Tura Ali ◽  
Zambri Samsudin
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Void Formation ◽  
Velocity Flow ◽  
Incomplete Filling ◽  
Underfill Flow ◽  
Dimensional Simulation ◽  
Volume Method ◽  
Capillary Underfill ◽  
Good Agreement

Abstract The conventional capillary underfill process has been a common practice in the industry, somehow the process is costly and time consuming. Thus, no-flow underfill process is developed to increase the effective lead time production since it integrates the simultaneous reflow and cure of the solder interconnect and underfill. This paper investigates the effect of different dispense patterns of no-flow underfill process by mean of numerical and experimental method. Finite volume method (FVM) was used for the three-dimensional simulation to simulate the compression flow of the no-flow underfill. Experiments were carried out to complement the simulation validity and the results from both studies have reached a good agreement. The findings show that of all three types of dispense patterns, the combined shape dispense pattern shows better chip filling capability. The dot pattern has the highest velocity and pressure distribution with values of 0.0172 m/s and 813 Pa, respectively. The high-pressure region is concentrated at the center of the chip and decreases out towards the edge. Low in pressure and velocity flow factor somehow lead to issue associated to possibility of incomplete filling or void formation. Dot dispense pattern shows less void formation since it produces high pressure underfill flow within the BGA. This paper provides reliable insight to the industry to choose the best dispense pattern of recently favorable no-flow underfill process.

Improving Aerodynamic Matching of Axial Compressor Blading Using a Three-Dimensional Multistage Inverse Design Method

2005 ◽  
Vol 129 (1) ◽  
pp. 108-118 ◽  
Author(s):  
M. P. C. van Rooij ◽  
T. Q. Dang ◽  
L. M. Larosiliere
Keyword(s):  
Inverse Method ◽  
Design Method ◽  
Three Dimensional ◽  
Computational Time ◽  
Design Calculation ◽  
Pressure Loading ◽  
Design Intent ◽  
Design Point ◽  
Analysis And Design ◽  
Blade Row

Current turbomachinery design systems increasingly rely on multistage CFD as a means to diagnose designs and assess performance potential. However, design weaknesses attributed to improper stage matching are addressed using often ineffective strategies involving a costly iterative loop between blading modification, revision of design intent, and further evaluation of aerodynamic performance. A scheme is proposed herein which greatly simplifies the design point blade row matching process. It is based on a three-dimensional viscous inverse method that has been extended to allow blading analysis and design in a multi-blade row environment. For computational expediency, blade row coupling is achieved through an averaging-plane approximation. To limit computational time, the inverse method was parallelized. The proposed method allows improvement of design point blade row matching by direct regulation of the circulation capacity of the blading within a multistage environment. During the design calculation, blade shapes are adjusted to account for inflow and outflow conditions while producing a prescribed pressure loading. Thus, it is computationally ensured that the intended pressure-loading distribution is consistent with the derived blading geometry operating in a multiblade row environment that accounts for certain blade row interactions. The viability of the method is demonstrated in design exercises involving the rotors of a 2.5 stage, highly loaded compressor. Individually redesigned rotors display mismatching when run in the 2.5 stage, evident as a deviation from design intent. However, simultaneous redesign of the rotors in their multistage environment produces the design intent, indicating that aerodynamic matching has been achieved.

Influence of Laser Soldering Temperatures On Thru-Hole Component

2021 ◽  
Author(s):  
Saiful Majdy ◽  
Mohamad Aizat Abas ◽  
Mohamad Fikri Mohd Sharif ◽  
Fakhrozi Che Ani
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Void Formation ◽  
Lead Free ◽  
Bottom Surface ◽  
Lead Free Solder ◽  
Soldering Process ◽  
Incomplete Filling ◽  
Laser Soldering ◽  
Free Solder

Abstract The conventional method of selective soldering has been practiced using wave soldering, convection reflow, and hand soldering. However, due to industry automation and high demand for quality, repeatability and flexibility, laser soldering process has been developed to meet these demands. This paper investigates the effect of different temperature of laser soldering process on lead free solder (SAC305) by means of numerical method that is validated by experiment. Finite Volume Method (FVM) was used for the three-dimensional (3D) simulation to simulate the filling flow of the lead-free solder. Experiments were carried out to complement simulation validity and the results of far both methods have reached a good agreement. The findings show that a better result can be achieved when angle of lead component (?le) approaches 90°. Using the optimized lead angle, five different temperature simulations were set in the range of 550K < T < 700K. The finding shows that, 600K has the best velocity and pressure distributions with average values of 63.3 mm/s and 101.1386kPa, respectively. The high-pressure region is concentrated at the top and bottom surface of solder pad. High difference in pressure and velocity spots somehow lead to issue associated with possibility of incomplete filling or void formation. 650K model shows less void formation since it produces high pressure filling flow within the solder region.

Three-Dimensional Numerical Simulation of Meso-Scale-Void Formation during the Mold-Filling Process of LCM

2019 ◽  
Vol 26 (4) ◽  
pp. 1121-1137 ◽  
Author(s):  
Chunyang Zhao ◽  
Bo Yang ◽  
Shilong Wang ◽  
Chi Ma ◽  
Sibao Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Three Dimensional ◽  
Void Formation ◽  
Mold Filling ◽  
Filling Process ◽  
Meso Scale

Scanning Electron Microscopy in Hybrid Microelectronics

1976 ◽  
Vol 34 ◽  
pp. 456-457
Author(s):  
S. Khadpe ◽  
R. Faryniak
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Integrated Circuit ◽  
Failure Modes ◽  
Three Dimensional ◽  
Circuit Components ◽  
Hybrid Microcircuit ◽  
Electrical Connections ◽  
Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

Analyzing the Impact of X-Ray Tomography on the Reliability of Integrated Circuits

2015 ◽  
Author(s):  
Halit Dogan ◽  
Md Mahbub Alam ◽  
Navid Asadizanjani ◽  
Sina Shahbazmohamadi ◽  
Domenic Forte ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
3D Imaging ◽  
Three Dimensional ◽  
Serial Sectioning ◽  
Promising Technique ◽  
Flash Memories ◽  
X Ray ◽  
3D Information ◽  
The Impact

Abstract X-ray tomography is a promising technique that can provide micron level, internal structure, and three dimensional (3D) information of an integrated circuit (IC) component without the need for serial sectioning or decapsulation. This is especially useful for counterfeit IC detection as demonstrated by recent work. Although the components remain physically intact during tomography, the effect of radiation on the electrical functionality is not yet fully investigated. In this paper we analyze the impact of X-ray tomography on the reliability of ICs with different fabrication technologies. We perform a 3D imaging using an advanced X-ray machine on Intel flash memories, Macronix flash memories, Xilinx Spartan 3 and Spartan 6 FPGAs. Electrical functionalities are then tested in a systematic procedure after each round of tomography to estimate the impact of X-ray on Flash erase time, read margin, and program operation, and the frequencies of ring oscillators in the FPGAs. A major finding is that erase times for flash memories of older technology are significantly degraded when exposed to tomography, eventually resulting in failure. However, the flash and Xilinx FPGAs of newer technologies seem less sensitive to tomography, as only minor degradations are observed. Further, we did not identify permanent failures for any chips in the time needed to perform tomography for counterfeit detection (approximately 2 hours).

scholarly journals A Proof-of-Concept Algorithm for the Retrieval of Total Column Amount of Trace Gases in a Multi-Dimensional Atmosphere

2021 ◽  
Vol 13 (2) ◽  
pp. 270
Author(s):  
Adrian Doicu ◽  
Dmitry S. Efremenko ◽  
Thomas Trautmann
Keyword(s):  
Trace Gases ◽  
Three Dimensional ◽  
Principal Component ◽  
Radiative Transfer Model ◽  
Computational Time ◽  
Transfer Model ◽  
Proof Of Concept ◽  
Discrete Ordinate ◽  
Distribution Method ◽  
Total Column

An algorithm for the retrieval of total column amount of trace gases in a multi-dimensional atmosphere is designed. The algorithm uses (i) certain differential radiance models with internal and external closures as inversion models, (ii) the iteratively regularized Gauss–Newton method as a regularization tool, and (iii) the spherical harmonics discrete ordinate method (SHDOM) as linearized radiative transfer model. For efficiency reasons, SHDOM is equipped with a spectral acceleration approach that combines the correlated k-distribution method with the principal component analysis. The algorithm is used to retrieve the total column amount of nitrogen for two- and three-dimensional cloudy scenes. Although for three-dimensional geometries, the computational time is high, the main concepts of the algorithm are correct and the retrieval results are accurate.

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