The study of cyanate ester underfill adhesives under typical flip chip assembly process conditions

2002 ◽  
Author(s):  
Quah Hong Tat ◽  
I.J. Rasiah
Keyword(s):  
Flip Chip ◽  
Cyanate Ester ◽  
Process Conditions ◽  
Assembly Process ◽  
Flip Chip Assembly

Flip-Chip Flux Evolution

2019 ◽  
Vol 2019 (1) ◽  
pp. 000115-000119 ◽  
Author(s):  
Andy Mackie ◽  
Hyoryoon Jo ◽  
Sze Pei Lim
Keyword(s):  
Flip Chip ◽  
Elevated Temperatures ◽  
High Volume ◽  
Automotive Electronics ◽  
Assembly Process ◽  
Surface Finishes ◽  
Solder Bumps ◽  
Thermocompression Bonding ◽  
Advanced Packaging ◽  
Flip Chip Assembly

Abstract Flip-chip assembly accounts for more than 80% of the advanced packaging technology platform, compared to fan-in, fan-out, embedded die, and through silicon via (TSV). Flip-chip interconnect remains a critical assembly process for large die used in artificial intelligence processors; thin die that warps at elevated temperatures; heterogeneous integration in SiP applications; flip-chip on leadframe; and MicroLED die usage. This paper will first outline trends in evolving flip-chip and direct chip placement (DCP) technology, then will examine the changing nature of the solder bump, the interconnect itself, and the substrate. Many variables of the flip-chip assembly process will be discussed, including standard solder bumps to micro Cu-pillar bumps with different alloys; different pad surface finishes of Cu OSP, NiAu, and solder on pad (SOP); and from regular pads on substrates to bond-on-trace applications. A major focus will be on flip-chip assembly methods, from old C4 conventional reflow processing to thermocompression bonding (TCB), and the latest laser assisted bonding (LAB) technology, with an emphasis on how the usage of different technologies necessitates different assembly materials, especially fluxes. Flip-chip fluxes such as the commonly used water-washable flux, the standard no-clean flux, and the ultra-low residue flux, and how these fluxes react to different processing methods, will be an area of discussion. Finally, the paper will examine the need for increased reliability as the technology inevitably moves into the high-volume, zero-defect arena of automotive electronics.

Effect of Compatibility between Fluxes and Cyanate Ester Underfill on Lead Free Flip Chip Assembly and Reliability

2006 ◽  
Vol 3 (1) ◽  
pp. 12-21
Author(s):  
Raghunandan Chaware ◽  
Leon Stiborek ◽  
Jeremias Libres ◽  
Manots Marquez ◽  
Charles Odegard ◽  
...  
Keyword(s):  
High Performance ◽  
Flip Chip ◽  
Cyanate Ester ◽  
Lead Free ◽  
Process Window ◽  
Flip Chips ◽  
Flip Chip Assembly ◽  
Materials Used ◽  
Moisture Resistant ◽  
Better Than

The quality and reliability of flip-chip assembly is severely impacted by the compatibility between various materials used in the package. Currently, no-clean fluxes are widely used for the assembly of flip chips. Poor compatibility between the flux residue and the underfill can lead to the formation of voids, and consequently, reliability problems. Therefore, a major concern for flip-chip assembly is the compatibility between the flux residues and the underfill. The principal objective of this research was to develop a flux for lead-free packaging, which would be compatible with high performance moisture resistant cyanate ester-based underfills. During this study, commercially available fluxes, along with tailor made epoxy-based flux, were tested for their compatibility with the underfill. The results indicated that the assembly process window for the rosin-based fluxes was much wider than the epoxy-based fluxes. Synthetic flux had poor soldering performance and relatively poor compatibility with the cyanate ester underfill than rosin-based flux. Epoxy flux exhibited narrow process window and the soldering performance was sensitive to flux thickness, reflow profile, substrate pad surface finish and topography. For smaller packages with die size of 10 mm by 10 mm, the compatibility between the cyanate ester underfill and the different fluxes was comparable. However, for the packages with die size of 22 mm by 22 mm, the compatibility between the epoxy-based flux and the cyanate ester underfill was relatively better than that with the other two flux chemistries.

High Yield, Near Void-Free Assembly Process of a Flip Chip in Package Using No-Flow Underfill

2010 ◽  
Vol 2010 (1) ◽  
pp. 000798-000805 ◽  
Author(s):  
Sangil Lee ◽  
Daniel F. Baldwin
Keyword(s):  
Flip Chip ◽  
Void Nucleation ◽  
Void Formation ◽  
Bubble Nucleation ◽  
Nucleation Theory ◽  
High Yield ◽  
Process Conditions ◽  
Assembly Process ◽  
Fine Pitch ◽  
Underfill Material

The advanced assembly process for a flip chip in package (FCIP) using no-flow underfill material presents challenges with high I/O density (over 3000 I/O) and fine-pitch (down to 150 μm) interconnect applications because it has narrowed the feasible assembly process window for achieving robust interconnect yield. In spite of such challenges, a high yield, nearly void-free assembly process has been achieved in the past research using commercial no-flow underfill material with a high I/O, fine pitch FCIP. The initial void area (approximately 7% ) could cause early failures such solders fatigue cracking or solder bridging in thermal reliability. Therefore, this study reviewed a classical bubble nucleation theory to predict the conditions of underfill void nucleation in the no flow assembly process. Based on the models prediction, systematic experiments were designed to eliminate underfill voiding using parametric studies. First, a void formation study investigated the effect of reflow parameter on underfill voiding and found process conditions of void-free assembly with robust interconnections. Second, a void formation characterization validated the determined reflow conditions to achieve a high yield and void-free assembly process, and the stability of assembly process using a large scale of assemblies respectively. This paper presents systematic studies into void formation study and void formation characterization through the use of structured experimentation which was designed to achieve a high yield, void-free assembly process leveraging a void formation model based on classical bubble nucleation theory. Indeed, the theoretical models were in good agreement with experimental results.

Corrections to "Ultra-fine pitch stencil printing for a low cost and low temperature flip-chip assembly process"

2007 ◽  
Vol 30 (2) ◽  
pp. 359-359
Author(s):  
Robert W. Kay ◽  
Stoyan Stoyanov ◽  
Greg P. Glinski ◽  
Chris Bailey ◽  
Marc P. Y. Desmulliez
Keyword(s):  
Low Temperature ◽  
Flip Chip ◽  
Low Cost ◽  
Assembly Process ◽  
Stencil Printing ◽  
Fine Pitch ◽  
Flip Chip Assembly

Influence of the Property of the Build-Up Package on Warpage at Flip Chip Assembly Process

2003 ◽  
Author(s):  
Yukihiko Toyoda ◽  
Yoichiro Kawamura ◽  
Hiroyoshi Hiei ◽  
Qiang Yu ◽  
Tadahiro Shibutani ◽  
...  
Keyword(s):  
Flip Chip ◽  
Electronic Device ◽  
New Product ◽  
High Density ◽  
Simulation Technique ◽  
Assembly Process ◽  
Reliability Problem ◽  
Fine Pitch ◽  
Flip Chip Assembly ◽  
Single Material

High density and integrated packaging of electronic device requires fine pitch. This packaging causes reliability problem in electronic device. One of them, warpage of the package occurred at chip assembly process may affect reliability. Therefore, if the simulation at the time of a chip assembly process is possible, it will be able to evaluate warpage in advance. It is very effective for development of a new product. Then, in this paper, the build-up package is regarded as a single material and the simulation technique of accuracy warpage at the time of chip assembly is reported. Next it is investigated the simulation technique for package warpage at the chip assembly process. Finnaly, it analyzed about the properties which affect warpage.

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