scholarly journals Transmission Properties of AuNi Coated Polymer Ball Joint and Sn58Bi Solder Joint for Flex-on-Board Interconnection

2022 ◽  
pp. 100099
Author(s):  
Shuye Zhang ◽  
Junyong Park ◽  
Gapyeol Park ◽  
Huijin Song ◽  
Joungho Kim ◽  
...  
Keyword(s):  
Solder Joint ◽  
Ball Joint ◽  
Transmission Properties

A Constriction Resistance Model in Thermal Analysis of Solder Ball Joints in Ball Grid Array Packages

1999 ◽  
Author(s):  
T. M. Ying ◽  
K. C. Toh
Keyword(s):  
Thermal Analysis ◽  
Solder Joint ◽  
Solder Ball ◽  
Heat Dissipation ◽  
Ball Grid Array ◽  
Internal Resistance ◽  
Ball Joint ◽  
Constriction Resistance ◽  
Resistance Model ◽  
Ball Joints

Abstract The constriction resistance model is employed for the thermal analysis at the solder ball joint of a Ball Grid Array (BGA) package. The behavior of heat dissipation in solder joint is also analyst through Finite Element Modeling (FEM) and compared with the analytical model. The principle of constriction and spreading resistances is analyzed in detail because of the geometrical complexity encountered in BGA solder joints. The total resistance across the solder joint includes the internal resistance and external resistance. The internal resistance, which is the main focus of the analysis, consists of material resistance and constriction resistance. It is a function of material conductivity, thermal boundary conditions and geometric parameters. FEM solutions are in good agreement with analytical results of thermal resistance for single solder ball joint and multiple solder ball joints. The analytical resistance provides an accurate prediction on the temperature drop across the array of solder balls and hence the overall performance of the BGA packages. The pitch size is the main parameter in the investigation to study the heat dissipation of solder ball joints.

Stereoscopic Drawings Made by Analog Computer of Three-Dimensional Surfaces Generated by Spatial Mechanism

1971 ◽  
Vol 93 (1) ◽  
pp. 239-250
Author(s):  
L. E. Torfason ◽  
F. R. E. Crossley
Keyword(s):  
Three Dimensional ◽  
Analog Computer ◽  
Ball Joint ◽  
Spatial Mechanism ◽  
Transmission Properties ◽  
Spatial Mechanisms ◽  
As If

Spatial mechanisms with up to five links and containing at least one ball joint can be solved by considering the intersection of the three dimensional surfaces which can be generated by portions of the mechanism. This paper presents a method whereby stereoscopic pairs of the surfaces can be drawn using an electronic analog computer and the figures viewed as if they were three dimensional. This results in a far better visualization of the surfaces. In many cases it can be seen what the type of intersection between surfaces is. This determines the gross motion of the mechanism, the limits of its motion, and an estimate of its transmission properties.

Ultrasonic Wave Scattering by a Line Crack in a Solder Joint

1999 ◽  
Vol 11 (1) ◽  
pp. 117-135
Author(s):  
P. Dineva ◽  
D. Gross ◽  
T. Rangelov
Keyword(s):  
Solder Joint ◽  
Ultrasonic Wave ◽  
Wave Scattering ◽  
Line Crack

Effect of Multiple Reflows on the Mechanical Reliability of Solder Joint in LED Package

2010 ◽  
Vol 48 (11) ◽  
pp. 1035-1040 ◽  
Author(s):  
Young-Chul Lee ◽  
Kwang-Seok Kim ◽  
Ji-Hyuk Ahn ◽  
Jeong-Won Yoon ◽  
Min-Kwan Ko ◽  
...  
Keyword(s):  
Solder Joint ◽  
Mechanical Reliability

Materials Characterization of Lead Free Compositions for Minimum Temperature SMT Processes at the SLI-Second Level Interconnect Solder Joint

2004 ◽  
Author(s):  
Norman J. Armendariz ◽  
Prawin Paulraj
Keyword(s):  
Solder Joint ◽  
Printed Circuit Board ◽  
Gold Surface ◽  
Circuit Board ◽  
Lead Free ◽  
Processing Temperature ◽  
The European Union ◽  
Printed Circuit ◽  
Higher Temperature ◽  
Tin Silver Copper

Abstract The European Union is banning the use of Pb in electronic products starting July 1st, 2006. Printed circuit board assemblies or “motherboards” require that planned CPU sockets and BGA chipsets use lead-free solder ball compositions at the second level interconnections (SLI) to attach to a printed circuit board (PCB) and survive various assembly and reliability test conditions for end-use deployment. Intel is pro-actively preparing for this anticipated Pb ban, by evaluating a new lead free (LF) solder alloy in the ternary Tin- Silver-Copper (Sn4.0Ag0.5Cu) system and developing higher temperature board assembly processes. This will be pursued with a focus on achieving the lowest process temperature required to avoid deleterious higher temperature effects and still achieve a metallurgically compatible solder joint. One primary factor is the elevated peak reflow temperature required for surface mount technology (SMT) LF assembly, which is approximately 250 °C compared to present eutectic tin/lead (Sn37Pb) reflow temperatures of around 220 °C. In addition, extended SMT time-above-liquidus (TAL) and subsequent cooling rates are also a concern not only for the critical BGA chipsets and CPU BGA sockets but to other components similarly attached to the same PCB substrate. PCBs used were conventional FR-4 substrates with organic solder preservative on the copper pads and mechanical daisychanged FCBGA components with direct immersion gold surface finish on their copper pads. However, a materials analysis method and approach is also required to characterize and evaluate the effect of low peak temperature LF SMT processing on the PBA SLI to identify the absolute limits or “cliffs” and determine if the minimum processing temperature and TAL could be further lowered. The SLI system is characterized using various microanalytical techniques, such as, conventional optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and microhardness testing. In addition, the SLI is further characterized using macroanalytical techniques such as dye penetrant testing (DPT) with controlled tensile testing for mechanical strength in addition to disbond and crack area mapping to complete the analysis.

Reballing/Rebumping Ultra-Fine Pitch Packages Less Than 0.5 mm Pitch for FA

2014 ◽  
Author(s):  
Bob Wettermann
Keyword(s):  
Solder Joint ◽  
Failure Analysis ◽  
Joint Strength ◽  
Semiconductor Devices ◽  
X Ray ◽  
Fine Pitch ◽  
Manual Methods

Abstract As the pitch and package sizes of semiconductor devices have shrunk and their complexity has increased, the manual methods by which the packages can be re-bumped or reballed for failure analysis have not kept up with this miniaturization. There are some changes in the types of reballing preforms used in these manual methods along with solder excavation techniques required for packages with pitches as fine as 0.3mm. This paper will describe the shortcomings of the previous methods, explain the newer methods and materials and demonstrate their robustness through yield, mechanical solder joint strength and x-ray analysis.

Development and testing of rolling cutter bit with a new arrangement of teeth on the balls

2020 ◽  
pp. 60-68
Author(s):  
V. A. Pyalchenkov ◽  
D. V. Pyalchenkov
Keyword(s):  
Axial Force ◽  
Axial Load ◽  
Vertical Line ◽  
Ball Joint ◽  
Line Passing

Research has found that the axial load applied to the bit is distributed unevenly along the crowns of the balls. The middle crowns are the busiest. The value of the axial force perceived by a separate ring is associated with the deformation of the details of the ball joint. You can reduce the uneven loading of crowns by shifting them along the ball along the radius of the bit, placing them so that the vertical line passing through the center of the lower ball of the lock bearing passes through the middle of the gap between the crowns of neighboring balls. The bits with the new option of placing the teeth on the balls were tested on the stand and in industrial conditions. For the bits of this design, the axial load was distributed more evenly over the crowns, which allowed increasing the efficiency of their work.

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