A practical investigation on nickel plated copper heat spreader with different catalytic activation processes for flip-chip ball grid array packages

2009 ◽  
Vol 49 (5) ◽  
pp. 537-543 ◽  
Author(s):  
Nowshad Amin ◽  
Victor Lim ◽  
Foong Chee Seng ◽  
Rozaidi Razid ◽  
Ibrahim Ahmad
Keyword(s):  
Flip Chip ◽  
Ball Grid Array ◽  
Heat Spreader ◽  
Catalytic Activation ◽  
Ball Grid Array Packages ◽  
Practical Investigation

Quality Monitors and Inspection Criteria for Bare Die Flip Chip Ball Grid Array and Bare Die PoP Packages.

2014 ◽  
Vol 2014 (1) ◽  
pp. 000533-000536
Author(s):  
Kiran Vanam ◽  
Anthony Newman ◽  
Mori Poustinchi ◽  
Stephen Stewart
Keyword(s):  
Form Factor ◽  
High Temperature ◽  
Flip Chip ◽  
Lower Cost ◽  
Smart Phone ◽  
Ball Grid Array ◽  
Heat Spreader ◽  
Fine Line ◽  
Key Drivers ◽  
Test Operations

Package form factor and cost are one of the key drivers in smart phone and tablet landscape. In order to meet these requirements hand held market has seen emergence of bare die flip chip ball grid array (BD FCBGA) and bare die package on package (BD PoP). As the name implies, these packages don't have a mold cap or heat spreader surrounding the silicon die resulting in lower cost and smaller form factor. Further package thickness reduction is possible by thinning of silicon die without significantly affecting high temperature (HT) warpage or coplanarity. One of the main concerns with aforementioned bare die package (BDP) configurations is die crack failure during assembly, testing, shipping or surface mount operation (SMT). The propensity of die crack failures further increases as thinner die is employed to meet overall package height requirements. This work focusses on evaluating various inspection tools for detecting gross die cracks to fine line cracks up to ~ 0.7 μm wide. Some of the key considerations for inspection tools, at assembly and test operations will be presented.

scholarly journals Measurement Capability of Laser Ultrasonic Inspection System for Evaluation of Ball-Grid Array Package Solder Balls

2021 ◽  
Vol 18 (4) ◽  
pp. 183-189
Author(s):  
Vishnu V. B. Reddy ◽  
Jaimal Williamson ◽  
Suresh K. Sitaraman
Keyword(s):  
Flip Chip ◽  
Ultrasonic Inspection ◽  
Reference Sample ◽  
Ball Grid Array ◽  
Inspection System ◽  
Laser Ultrasonic ◽  
Fiber Array ◽  
Measurement Capability ◽  
Repeatability And Reproducibility ◽  
Ball Grid Array Packages

Abstract Laser ultrasonic inspection is a novel, noncontact, and nondestructive technique to evaluate the quality of solder interconnections in microelectronic packages. In this technique, identification of defects or failures in solder interconnections is performed by comparing the out-of-plane displacement signals, which are produced from the propagation of ultrasonic waves, from a known good reference sample and sample under test. The laboratory-scale dual-fiber array laser ultrasonic inspection system has successfully demonstrated identifying the defects and failures in the solder interconnections in advanced microelectronic packages such as chip-scale packages, plastic ball grid array packages, and flip-chip ball grid array packages. However, the success of any metrology system depends upon precise and accurate data to be useful in the microelectronic industry. This paper has demonstrated the measurement capability of the dual-fiber array laser ultrasonic inspection system using gage repeatability and reproducibility analysis. Industrial flip-chip ball grid array packages have been used for conducting experiments using the laser ultrasonic inspection system and the inspection data are used to perform repeatability and reproducibility analysis. Gage repeatability and reproducibility studies have also been used to choose a known good reference sample for comparing the samples under test.

Evaluation of Thermal Enhancements to Flip-Chip-Plastic Ball Grid Array Packages

2004 ◽  
Vol 126 (4) ◽  
pp. 449-456 ◽  
Author(s):  
K. Ramakrishna ◽  
T.-Y. Tom Lee
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Forced Convection ◽  
Thermal Performance ◽  
Flip Chip ◽  
Transfer Problem ◽  
Printed Wiring Board ◽  
Heat Spreader ◽  
Plastic Ball ◽  
Ball Grid Array Packages

Enhancements to thermal performance of FC-PBGA packages due to underfill thermal conductivity, controlled collapse chip connection (C4) pitch, package to printed wiring board (PWB) interconnection through thermal balls, a heat spreader on the backside of the die, and an overmolded die with and without a heat spreader have been studied by solving a conjugate heat transfer problem. These enhancements have been investigated under natural and forced convection conditions for freestream velocities up to 2 m/s. The following ranges of parameters have been covered in this study: substrate size: 25–35 mm, die size: 6.19×7.81 mm (48 mm2 area) and 9.13×12.95 mm (118 mm2 area), underfill thermal conductivity: 0.6–3.0 W/(m K), C4 pitch: 250 μm and below, no thermal balls to 9×9 array of thermal balls on 1.27 mm square pitch, and with copper heat spreader on the back of a bare and an overmolded die. Based on our previous work, predictions in this study are expected to be within ±10% of measured data. The conclusions of the study are: (i) Thermal conductivity of the underfill in the range 0.6 to 10 W/(m K) has negligible effect on thermal performance of FC-PBGA packages investigated here. (ii) Thermal resistances decrease 12–15% as C4 pitch decreases below 250 μm. This enhancement is smaller with increase in die area. (iii) Thermal balls connected to the PTHs in the PWB decrease thermal resistance of the package by 10–15% with 9×9 array of thermal balls and PTHs compared to no thermal balls. The effect of die size on this enhancement is more noticeable on junction to board thermal resistance, Ψjb, than the other two package thermal metrics. (iv) Heat spreader on the back of the die decreases junction-to-ambient thermal resistance, Θja, by 6% in natural convection and by 25% in forced convection. (v) An overmolded die with a heat spreader provides better a thermal enhancement than a heat spreader on a bare die for freestream velocities up to about 1 m/s. Beyond 1 m/s, a heat spreader on bare die has better thermal performance.

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