Assembly and Scaling Challenges for 2.5D IC

2014 ◽  
Vol 2014 (1) ◽  
pp. 000606-000611 ◽  
Author(s):  
Liang Wang ◽  
Charles G. Woychik ◽  
Guilian Gao ◽  
Scott McGrath ◽  
Hong Shen ◽  
...  
Keyword(s):  
High Volume ◽  
Thermal Dissipation ◽  
Test Vehicle ◽  
Advantages And Disadvantages ◽  
Interconnect Delay ◽  
Critical Areas ◽  
Temporary Bonding ◽  
Advanced Packaging ◽  
Computing Performance ◽  
Material Process

2.5D technology is gaining acceptance in the industry and an increasing number of products are beginning to enter volume manufacturing. As with all interconnect technologies, the key metrics driving the transition include higher computing performance, lower power consumption, smaller form factor, increased bandwidth and reduced latency (interconnect delay). In order to transition from today's low volumes to High Volume Manufacturing (HVM), the concerns of warpage control, thermal dissipation, cost (yield and throughput) and overall technology scalability for future generations need to be addressed rapidly. The solutions in these relatively new packaging technologies encompass design/layout, material, process and integration choices. With these concerns as a backdrop, our paper will discuss our approach to optimizing 2.5D assembly for HVM. We will begin with a review of our test vehicle and our overall choices of substrate, interposer and die dimensions. Three different 2.5D assembly approaches that have been investigated at Invensas for warpage control, ease of process, and impact on yield and reliability will be discussed in detail. We will present our results from critical areas including temporary bonding, thermo-compression bonding, mass reflow, thin wafer/die handling, flux, underfill and molding. This paper will present our understanding of the underlying principles governing the technology bottlenecks in advanced packaging and the three flows will be compared with an assessment of their advantages and disadvantages. In addition, we will also provide the results of our cost modeling work. We will finish by making recommendations for an optimized assembly process flow.

Challenges of Scalable 2.5D IC Assembly

2015 ◽  
Vol 12 (3) ◽  
pp. 123-128
Author(s):  
Liang Wang ◽  
Charles G. Woychik ◽  
Guilian Gao ◽  
Grant Villavicencio ◽  
Scott McGrath ◽  
...  
Keyword(s):  
High Volume ◽  
Thermal Dissipation ◽  
Electrical Performance ◽  
High Yield ◽  
Design Stage ◽  
Advantages And Disadvantages ◽  
Interconnect Delay ◽  
Temporary Bonding ◽  
Thermocompression Bonding ◽  
Advanced Packaging

Driven by key metrics, including higher computing performance, lower power consumption, smaller form factor, increased bandwidth, and reduced latency (interconnect delay), the semiconductor interconnect technology is transitioning to 2.5D and gaining acceptance in the industry, as an increasing number of products are beginning to enter volume manufacturing. To transition from today's low volumes to high volume manufacturing (HVM), the concerns of warpage control, thermal dissipation, cost (yield and throughput), and overall technology scalability for future generations need to be addressed rapidly. The solutions in these relatively new packaging technologies encompass design/layout, material, process, and integration choices. With these concerns as a backdrop, our article will discuss our approach to optimizing 2.5D assembly for HVM. This article starts with a review of our test vehicle and our overall choices of substrate, interposer, and die dimensions. Three different 2.5D assembly approaches that have been investigated for warpage control, ease of process, and impact on yield and reliability will be discussed in detail. It is our finding that for achieving high yield and reliability, in the design stage of the system detailed considerations must be given to not only the electrical performance and signal integrity but also the thermal and mechanical behavior of the system in operation as well as the entire process history. This article reports our results from critical areas including temporary bonding, thermocompression bonding, mass reflow, thin wafer/die handling, flux, underfill, and molding. This article also presents our understanding of the underlying principles governing the technology bottlenecks in advanced packaging and the three flows will be compared with an assessment of their advantages and disadvantages. In the last portion of this article, recommendations are made for an optimized assembly process flow.

Wafer Thinning for Advanced Packaging Applications

2017 ◽  
Vol 2017 (DPC) ◽  
pp. 1-26
Author(s):  
Laura Mauer ◽  
John Taddei ◽  
Scott Kroeger
Keyword(s):  
Low Cost ◽  
High Volume ◽  
Alternative Methods ◽  
Critical Element ◽  
Wafer Level ◽  
Temporary Bonding ◽  
Scale Down ◽  
Advanced Packaging ◽  
Wafer Thinning ◽  
Etch Profile

Driven largely by the growing need for more data, increased functionality, and faster speeds, consumer electronic devices have sparked a revolution in IC design. As it becomes increasingly more expensive and technically challenging to scale down semiconductor devices, Moore's law is yielding to the concept of “More than Moore”, which is driving integrated functionality in smaller and thinner packages. Packaging for 2.5D and 3D has become critical to new products requiring higher performance and increased functionality in a smaller package. The use of a Through Silicon Via (TSV) has been discussed as a method for stacking die to achieve a vertical interconnect. The high costs associated with this technology have limited TSV use to a few applications such as high-bandwidth memory and logic, slowing its adoption within the industry. Lower-cost advanced packaging concepts have been developed and are now in high-volume production. Recently, alternative methods for exploiting the z-direction have turned to variations of Fan-Out Wafer Level Packaging (FOWLP), which do not include TSVs. In many of these concepts there is a need to thin the wafer to remove all of the silicon while being selective and not etching a variety of other films that include oxides, nitrides, and metals. In addition, there can be temporary bonding adhesives and mold compounds encapsulating the chips; these must remain undamaged. Another critical element of a successful process is the ability to control the profile of the silicon etch to provide uniform removal. The single wafer wet etching techniques and advanced process control developed for TSV Reveal are applicable to these structures and provide a low-cost alternative to CMP and Plasma processes. To successfully execute the process, several characteristics must be met: the silicon overburden depth and profile need to be determined, the overburden thinning etch needs a fast sculpting etchant, and the finishing etchant needs to be selective to materials that will be exposed at the completion of the etch. In addition, the tool used to perform this sequence needs to have the correct metrology capability, along with properly chosen etchants. Similarly, it is not sufficient to know the required etch profile, the software must be able to execute a unique etch profile for each wafer. In this fashion, the finishing etch time can be kept to a minimum. This is important, as many of the selective etchants have a slow etch rate, and adhesives used do not always hold up to exposure to the chemistries involved for long periods. This paper discusses the use of wet etch wafer thinning processes for new FOWLP applications.

High Heat Resistant Peelable Temporary Bonding Film and New Debonding System with Xe Flash Light Irradiation

2020 ◽  
Vol 2020 (1) ◽  
pp. 000302-000306
Author(s):  
Yuta Akasu ◽  
Emi Miyazawa ◽  
Tetsuya Enomoto ◽  
Yasuyuki Oyama ◽  
Shogo Sobue ◽  
...  
Keyword(s):  
Chemical Resistance ◽  
High Heat ◽  
Light Irradiation ◽  
Wafer Surface ◽  
Assembly Process ◽  
Test Vehicle ◽  
Packaging Process ◽  
Release System ◽  
Temporary Bonding ◽  
Carrier Wafer

Abstract We have developed a new temporary bonding film (TBF) and new debonding system with Xe flash light irradiation, named photonic release system, for advanced package assembly process. Since new TBF has a high Tg over 200 °C after curing and shows good chemical resistance to developer, resist stripper, and plating chemicals, no delamination, voiding, and swelling were observed after thermal and chemical treatment in the bonded structure of wafer and glass carrier. In addition, by adopting a metal-sputtered glass carrier, wafer could be debonded by Xe flash light irradiation in less than 1 ms through the glass carrier with no damage. Residual TBF on the wafer surface could be peeled off smoothly at ambient temperature without residue on the wafer. In this research, we also demonstrated the good applicability of this temporary bonding film to the typical packaging process by using test vehicle including 12 inch mold wafer and the advantage of photonic release system.

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.

Assembly Equipment Requirements for Next Generation Advanced Packaging

2016 ◽  
Vol 2016 (1) ◽  
pp. 000321-000325
Author(s):  
Bob Chylak ◽  
Horst Clauberg ◽  
Tom Strothmann
Keyword(s):  
Capital Investment ◽  
Flip Chip ◽  
High Volume ◽  
Electrical Performance ◽  
Wafer Level ◽  
Considerable Uncertainty ◽  
Thermocompression Bonding ◽  
Advanced Packaging ◽  
The Impact ◽  
3D Package

Abstract Device packaging is undergoing a proliferation of assembly options within the ever-expanding category of Advanced Packaging. Fan Out-Wafer Level Packages are achieving wide adoption based on improved performance and reduced package size and new System in Package products are coming to market in FOWLP, 2.5D and 3D package formats with the full capability to leverage heterogeneous integration in small package profiles. While the wide-spread adoption of thermocompression bonding and 2.5D packages predicted several years ago has not materialized to the extent predicted, advanced memory modules assembled by TCB are in high volume manufacturing, as are some high-end GPUs with integrated memory on Si interposer. High accuracy flip chip has been pushed to fine pitches that were difficult to imagine only three years ago and innovation in substrates and bonder technology is pushing the throughput and pitch capability even further. The packaging landscape, once dominated by a few large assembly providers, now includes turn-key packaging initiatives from the foundries with an expanding set of fan-out packing options. The fan-out processes include face-up and face-down methods, die first and die last methods and 2.5D or 3D package options. Selection of the most appropriate packaging technology from the combined aspects of electrical performance, form-factor, yield and cost presents a complex problem with considerable uncertainty and high risk for capital investment. To address this problem, the industry demands flexible manufacturing solutions that can be modified and upgraded to accommodate a changing assembly environment. This presentation will present the assembly process flows for various packaging options and discuss the key aspects of the process that influence throughput, accuracy and other key quality metrics, such as package warpage. These process flows in turn impose design constraints on submodules of the bonder. It will be shown that thoughtfully designed machine architecture allows for interchangeable and upgradeable submodules that can support nearly the entire range of assembly options. As an example, a nimble, low weight, medium force, constant heat bondhead for high throughput FOWLP can be interchanged with a high force, pulse heater bondhead to support low stress/low warpage thermocompression bonding. The various configuration options for a flexible advanced packaging bonder will be reviewed along with the impact of configuration changes on throughput and accuracy.

Issues in Assembly Process of Fine Pitch Chip-on-Flex Packages for LCD Applications

2004 ◽  
Author(s):  
Changsoo Jang ◽  
Seongyoung Han ◽  
Jay Ryu ◽  
Hangyu Kim
Keyword(s):  
Bonding Process ◽  
Conductive Adhesive ◽  
Assembly Process ◽  
Anisotropic Conductive Adhesive ◽  
Advantages And Disadvantages ◽  
Fine Pitch ◽  
Laser Bonding ◽  
Material Process ◽  
Process Combination ◽  
Underfill Material

Some of the current assembly issues of fine pitch chip-on-flex (COF) packages for LCD applications are reviewed. Traditional underfill material, anisotropic conductive adhesive (ACA) and non-conductive adhesive (NCA) are considered in conjunction with two applicable bonding methods including thermal and laser bonding. Advantages and disadvantages of each material/process combination are identified. Their applicability is further investigated to identify a process most suitable to the fine pitch packages (less than 40 μm). Numerical results and subsequent testing results indicate that NCA/laser bonding process produces most reliable joint for the fine pitch packages.

Design and Economic Considerations to Achieve the Price Parity of SiC MOSFETs with Silicon IGBTs

2016 ◽  
Vol 858 ◽  
pp. 889-893
Author(s):  
Woong Je Sung ◽  
B. Jayant Baliga
Keyword(s):  
Cost Analysis ◽  
High Volume ◽  
Next Generation ◽  
Packaging Technology ◽  
Processing Cost ◽  
Chip Size ◽  
Advanced Packaging ◽  
Economic Considerations ◽  
Intuitive Model

This paper aims to establish an intuitive model to determine the chip size of 1200V SiC MOSFET for a particular current rating. In order to provide the direction of next generation SiC MOSFETs, the most vital device parameters were investigated, and their quantitative influences are given. Cost analysis, based on the proposed method, shows that it is feasible to achieve the price parity to Silicon IGBTs by concurrent efforts such as improvements on the device innovation, advanced packaging technology, and reduced processing cost by leveraging high volume commercial 150 mm Si Foundries in US.

scholarly journals Comparative analysis of various Image compression techniques for Quasi Fractal lossless compression

2020 ◽  
Vol 2 (2) ◽  
pp. 30-45
Author(s):  
Satyawati Magar ◽  
Bhavani Sridharan
Keyword(s):  
Image Compression ◽  
Quality Parameters ◽  
Vital Role ◽  
Hybrid Technique ◽  
Brain Images ◽  
Biomedical Image ◽  
Advantages And Disadvantages ◽  
Critical Areas ◽  
Important Quality ◽  
Two Parameters

The most important Entity to be considered in Image Compression methods are Paek to signal noise ratio and Compression ratio. These two parameters are considered to judge the quality of any Image.and they a play vital role in any Image processing applications. Biomedical domain is one of the critical areas where more image datasets are involved for analysis and biomedical image compression is very, much essential. Basically, compression techniques are classified into lossless and lossy. As the name indicates, in the lossless technique the image is compressed without any loss of data. But in the lossy, some information may loss. Here both lossy & lossless techniques for an image compression are used. In this research different compression approaches of these two categories are discussed and brain images for compression techniques are highlighted. Both lossy and lossless techniques are implemented by studying it’s advantages and disadvantages. For this research two important quality parameters i.e. CR & PSNR are calculated. Here existing techniques DCT, DFT, DWT & Fractal are implemented and introduced new techniques i.e Oscillation Concept method, BTC-SPIHT & Hybrid technique using adaptive threshold & Quasi Fractal Algorithm.

Temporary Bonding Cost Of Ownership: The link between low total thickness variation and chip yield

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001893-001912
Author(s):  
Thomas Uhrmann ◽  
Jürgen Burggraf ◽  
Harald Wiesbauer ◽  
Julian Bravin ◽  
Thorsten Matthias ◽  
...  
Keyword(s):  
Chemical Stability ◽  
High Volume ◽  
Bonding Process ◽  
Thickness Variation ◽  
Total Thickness ◽  
Process Yield ◽  
Cost Of Ownership ◽  
Temporary Bonding ◽  
Total Thickness Variation ◽  
Determining Factor

The ability to process thin wafers with thicknesses of 20-50um on front- and backside is a key technology for 3D stacked ICs (3Ds-IC). The most obvious reason for thin wafers is the reduced form factor, which is especially important for handheld consumer devices. However, probably even more important is that thinner wafers enable significant cost reduction for TSVs. Consensus has developed on the use of Temporary Bonding / Debonding Technology as the solution of choice for reliably handling thin wafers through backside processing steps. Temporary bonding and debonding comprises several processes for which yield is essential, as costly fully functional device wafers are being processed. The presented temporary bonding process consists of a bi-layer system, a release layer, Dow Corning WL-3001 Bonding Release and an adhesive layer, Dow Corning WL-4030 or WL-4050 Bonding Adhesive, processed on EVG's 850XT universal temporary bonding and debonding platform. Furthermore, this bi-layer spin coated material allows a room temperature bonding-debonding process increase process throughput which translates to low cost of ownership for high volume manufacturing. As such, this bi-layer approach features high chemical stability exposed to phosphoric acid, nitric acid, organic solvents and other chemicals familiar to TSV fabrication. Besides chemical stability this adhesive system provides also a high thermal stability when exposed to temperatures up to 300 °C. The temporary bonding process yield has a major impact on the overall Cost of Ownership (CoO). On the other hand, throughput of the individual process steps like spin coating, bonding, cure, debonding and cleaning processes is the second determining factor for improved CoO. In this presentation, we will present a study of the total thickness variation (TTV) and the evolution of TTV at different stages of the process. High resolution in-line metrology is an enabling tool to trace the bond integrity and yield throughout backside processing. As TTV is a major determining factor of the overall process yield, understanding its impact over the bonded wafer pair carries major importance. Especially, non-continuity of the edge region, showing an inherent edge bead after coating, and edge die yield will be focus of our contribution. Finally, our experimental results will be transferred into a cost of ownership model, discussing the pros and cons for high volume production.

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