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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| Format: | Thesis |
| Language: | English |
| Published: |
2020
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| Subjects: | |
| 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 |
| _version_ | 1797011783595065344 |
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| author | Lim, Shaw Fa |
| author_facet | Lim, Shaw Fa |
| author_sort | Lim, Shaw Fa |
| collection | USM |
| 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. |
| first_indexed | 2024-03-06T15:39:21Z |
| format | Thesis |
| id | usm.eprints-47543 |
| institution | Universiti Sains Malaysia |
| language | English |
| last_indexed | 2024-03-06T15:39:21Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | usm.eprints-475432021-11-17T03:42:09Z 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. |
| 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 |
| title | 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_short | 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 |
| topic | T Technology TJ1-1570 Mechanical engineering and machinery |
| url | http://eprints.usm.my/47543/1/Warpage%20Behavior%20Of%20Thin%20Fcbga%20Package%20And%20Prediction%20Of%20Its%20First%20Interconnect%20Snag%20Solder%20Joint%20Shape.pdf |
| work_keys_str_mv | AT limshawfa warpagebehaviorofthinfcbgapackageandpredictionofitsfirstinterconnectsnagsolderjointshape |