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Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape

The influence of substrate copper density distribution, substrate bump coplanarity, stiffener attach process, and substrate clamping by magnetic boat during die attach towards Flip Chip Ball Grid Array (FCBGA) assembled package warpage were evaluated. The substrate warpage behavior throughout the...

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Main Author: Lim, Shaw Fa
Format: Thesis
Language:English
Published: 2020
Subjects:
T Technology
TJ1-1570 Mechanical engineering and machinery
Online Access:http://eprints.usm.my/47543/1/Warpage%20Behavior%20Of%20Thin%20Fcbga%20Package%20And%20Prediction%20Of%20Its%20First%20Interconnect%20Snag%20Solder%20Joint%20Shape.pdf
http://eprints.usm.my/47543/
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spelling my.usm.eprints.47543 http://eprints.usm.my/47543/ Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape Lim, Shaw Fa T Technology TJ1-1570 Mechanical engineering and machinery The influence of substrate copper density distribution, substrate bump coplanarity, stiffener attach process, and substrate clamping by magnetic boat during die attach towards Flip Chip Ball Grid Array (FCBGA) assembled package warpage were evaluated. The substrate warpage behavior throughout the package assembly process was characterized using shadow moiré. In this study, it was found that a balanced substrate copper density distribution (50/50 ratio), pre-stiffener substrate before flip chip bump reflow, and substrate clamping during reflow able to reduce flip chip solder bridging fall-out. The decrease in solder bridging <1% was due to the lower substrate warpage seen during die attach. In particular, solder bridging fall-out was well-correlated to die attach area warpage. Substrate with and without clamping during reflow has met the package reliability requirement of temperature cycle 1200 condition G (–40 °C to +125 °C). Simulation works through FEA (ANSYS) on the bare substrate and package warpage was carried out and correlated to experiment data. Various material properties and package designs was evaluated from the correlated FEA model and its respective warpage behavior was understood. With understading of warpage data through FEA, SnAg solder joint shape and its solder bridging can be understood through Surface Evolver. The effect of solder volume, gap height and Under Bump Metalization (UBM) size towards solder joint was evaluated. Higher solder volume and smaller gap height led to higher occurrence of solder bridging. Solder joint formation through solder cap copper pillar onto copper trace was predicted through Surface Evolver. It can be shown that copper pillar solder joint geometry can be successfully simulated and agreed with experiment. The relationship between various solder joint influencing factors such as die bump diameters, copper pad geometry, solder height and solder volume were established. The optimum die bump to copper pad width ratio can be obtained through this simulation work. The information can be used to estimate critical volume of solder needed for new, smaller pitch die bump and copper pad design which help to save cost and time by avoiding a large number of experiments prior to mass production. 2020-04-01 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/47543/1/Warpage%20Behavior%20Of%20Thin%20Fcbga%20Package%20And%20Prediction%20Of%20Its%20First%20Interconnect%20Snag%20Solder%20Joint%20Shape.pdf Lim, Shaw Fa (2020) Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape. PhD thesis, Universiti Sains Malaysia.
institution Universiti Sains Malaysia
building Hamzah Sendut Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Sains Malaysia
content_source USM Institutional Repository
url_provider http://eprints.usm.my/
language English
topic T Technology
TJ1-1570 Mechanical engineering and machinery
spellingShingle T Technology
TJ1-1570 Mechanical engineering and machinery
Lim, Shaw Fa
Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
description The influence of substrate copper density distribution, substrate bump coplanarity, stiffener attach process, and substrate clamping by magnetic boat during die attach towards Flip Chip Ball Grid Array (FCBGA) assembled package warpage were evaluated. The substrate warpage behavior throughout the package assembly process was characterized using shadow moiré. In this study, it was found that a balanced substrate copper density distribution (50/50 ratio), pre-stiffener substrate before flip chip bump reflow, and substrate clamping during reflow able to reduce flip chip solder bridging fall-out. The decrease in solder bridging <1% was due to the lower substrate warpage seen during die attach. In particular, solder bridging fall-out was well-correlated to die attach area warpage. Substrate with and without clamping during reflow has met the package reliability requirement of temperature cycle 1200 condition G (–40 °C to +125 °C). Simulation works through FEA (ANSYS) on the bare substrate and package warpage was carried out and correlated to experiment data. Various material properties and package designs was evaluated from the correlated FEA model and its respective warpage behavior was understood. With understading of warpage data through FEA, SnAg solder joint shape and its solder bridging can be understood through Surface Evolver. The effect of solder volume, gap height and Under Bump Metalization (UBM) size towards solder joint was evaluated. Higher solder volume and smaller gap height led to higher occurrence of solder bridging. Solder joint formation through solder cap copper pillar onto copper trace was predicted through Surface Evolver. It can be shown that copper pillar solder joint geometry can be successfully simulated and agreed with experiment. The relationship between various solder joint influencing factors such as die bump diameters, copper pad geometry, solder height and solder volume were established. The optimum die bump to copper pad width ratio can be obtained through this simulation work. The information can be used to estimate critical volume of solder needed for new, smaller pitch die bump and copper pad design which help to save cost and time by avoiding a large number of experiments prior to mass production.
format Thesis
author Lim, Shaw Fa
author_facet Lim, Shaw Fa
author_sort Lim, Shaw Fa
title Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
title_short Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
title_full Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
title_fullStr Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
title_full_unstemmed Warpage Behavior Of Thin Fcbga Package And Prediction Of Its First Interconnect Snag Solder Joint Shape
title_sort warpage behavior of thin fcbga package and prediction of its first interconnect snag solder joint shape
publishDate 2020
url http://eprints.usm.my/47543/1/Warpage%20Behavior%20Of%20Thin%20Fcbga%20Package%20And%20Prediction%20Of%20Its%20First%20Interconnect%20Snag%20Solder%20Joint%20Shape.pdf
http://eprints.usm.my/47543/
_version_ 1717094494458871808
score 13.211869

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