Effects of Solder Volume and Reflow Conditions on Self-Alignment Accuracy for Fan-Out Package Applications

2017 ◽  
Vol 47 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Hwan-Pil Park ◽  
Gwancheol Seo ◽  
Sungchul Kim ◽  
Young-Ho Kim
Keyword(s):  
Alignment Accuracy ◽  
Solder Volume

Influences of Solder Wetting on Self-Alignment Accuracy and Modeling for Optoelectronic Devices Assembly

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Ming Kong ◽  
Sungeun Jeon ◽  
Chiwon Hwang ◽  
Y. C. Lee
Keyword(s):  
Three Dimensional ◽  
Critical Factor ◽  
Cost Effective ◽  
Optimization Method ◽  
Alignment Accuracy ◽  
Factors Affecting ◽  
Solder Bumps ◽  
Solder Volume ◽  
Incomplete Wetting ◽  
External Forces

Solder self-alignment is an important phenomenon enabling cost-effective optoelectronics assembly. In this study, the wetting of Sn-rich solder to under bump metallization (UBM) pads is identified as a critical factor affecting self-alignment accuracy. Incomplete wetting of solder to the metallization pads is responsible for chip-to-substrate misalignment larger than 1 μm, while fabrication tolerances, such as solder volume variation and pad diameter deviation, only account for misalignments in the submicron range. To quantitatively investigate the effect of incomplete wetting on self-alignment accuracy, a three-dimensional (3D) model based on a force optimization method was developed. With the input parameters of incomplete solder metallurgical wetting area, position and diameter of metallization pad, volume of individual solder bumps, coefficient of solder surface tension, mass of the chip, external forces acting on the chip, and initial pick-and-place position of the chip before assembly, the model predicts the assembled position of the chip in terms of the misalignments in the X-Y plane and the rotation angle along the Z axis. The model further confirmed that incomplete wetting of solder is the most critical modulator among the undesirable factors affecting solder self-alignment accuracy.

Effects of Solder Wetting on Self-Alignment Accuracy and Modeling for Optoelectronics Assembly

2010 ◽  
Author(s):  
Ming Kong ◽  
Sungeun Jeon ◽  
Chiwon Hwang ◽  
Y. C. Lee
Keyword(s):  
Flip Chip ◽  
Critical Factor ◽  
Cost Effective ◽  
Alignment Accuracy ◽  
Factors Affecting ◽  
Solder Volume ◽  
Pick And Place ◽  
Design And Manufacturing ◽  
On Chip ◽  
External Forces

Solder self-alignment is one of the most important technologies for cost effective optoelectronics assembly. In this study, the wetting of Sn-rich solder to the metal pads of chip and substrate was identified as a critical factor significantly affecting self-alignment accuracy during the assembly. Insufficient wetting of solder to the metallization pads was responsible for large chip-to-substrate misalignment post-assembly, while fabrication deviations, such as solder volume variation and pad diameter deviation, only account for misalignments in the range of submicrons. To aid the design of flip-chip assemblies requiring high alignment accuracy, a force optimization model was developed and validated experimentally. With the input parameters of design and manufacturing process for optoelectronics flip-chip assembly using solders, such as insufficient solder metallurgical wetting areas, positions and diameters of metallization pads, volume of individual solder bump, coefficient of solder surface tension, mass of chip, external forces acting on chip, and initial pick-and-place position of chip before assembly, the model predicts the assembled position of the chip in terms of the misalignments in the X-Y planes and the rotation angles along the Z axis. The model further confirmed that insufficient wetting of solder is the most critical modulator among the undesirable factors affecting solder self-alignment accuracy.

A Precision Alignment Method to <100> Direction on (110) Silicon Wafer

2001 ◽  
Author(s):  
Fan-Gang Tseng ◽  
Kai-Chen Chang
Keyword(s):  
Silicon Wafer ◽  
Crystal Orientation ◽  
Silicon Wafers ◽  
Innovative Approach ◽  
Alignment Accuracy ◽  
Alignment Method

Abstract This paper proposes a novel pre-etch method to determine the lt;100gt; direction on (110) silicon wafers for bulk etching. Series of circular windows were arranged in an arc of radius 48.9 mm, and bulk-etched to form hexagonal shapes for crystal orientation finding. The corners of the hexagons can be used as an alignment reference for the indication of the lt;100gt; direction on (110) silicon wafers. This innovative approach has been demonstrated experimentally to give an orientation-alignment accuracy of ± 0.03° for (110) wafers with 4-inch diameter.

Effect of Mechanical Alignment System on Assembly Accuracy

2000 ◽  
Author(s):  
Neville K. S. Lee ◽  
Grace H. Yu ◽  
Y. Zou ◽  
J. Y. Chen ◽  
Ajay Joneja
Keyword(s):  
Alignment Accuracy ◽  
Mechanical Alignment ◽  
Mechanical Assembly ◽  
Surface Waviness ◽  
Form Errors ◽  
Multi Stage ◽  
Assembly Accuracy ◽  
Alignment System ◽  
Simulation Based ◽  
Selection Of

Abstract Mechanical means of positioning are frequently used in mechanical assembly processes. However, very little attention has been paid to the selection of mechanical alignment systems (MAS) for assembly processes. Our analysis shows that if the MAS are not properly selected, the form errors as well surface waviness and roughness of the workpieces to be assembled can badly limit the level of accuracy achievable. A simulation-based methodology is described to study the alignment accuracy for multi-stage processes. Such cases are common, where fabrication operations are done on parts before they are assembled. The study shows that if the workpieces are aligned in the same orientation, using similar or identical MAS for the fabrication processes and assembly processes, then the effect of the form errors as well as surface waviness and roughness of the workpieces can be greatly suppressed.

scholarly journals Evaluation of PSI-BLAST alignment accuracy in comparison to structural alignments

2000 ◽  
Vol 9 (11) ◽  
pp. 2278-2284 ◽  
Author(s):  
Iddo Friedberg ◽  
Tommy Kaplan ◽  
Hanah Margalit
Keyword(s):  
Alignment Accuracy ◽  
Blast Alignment ◽  
Structural Alignments

Void-free BCB adhesive wafer bonding with high alignment accuracy

2014 ◽  
Vol 21 (8) ◽  
pp. 1633-1641 ◽  
Author(s):  
Zhen Song ◽  
Zhimin Tan ◽  
Litian Liu ◽  
Zheyao Wang
Keyword(s):  
Wafer Bonding ◽  
Alignment Accuracy
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