Patterned Permanent Bonding of Benzocyclobutene Based Dielectric Materials for Advanced Wafer Level Packaging

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 000886-000912
Author(s):  
Jong-Uk Kim ◽  
Anupam Choubey ◽  
Rosemary Bell ◽  
Hua Dong ◽  
Michael Gallagher ◽  
...  
Keyword(s):  
Wafer Bonding ◽  
Dielectric Materials ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Integration Schemes ◽  
Device Reliability ◽  
Package Size ◽  
Microelectronics Industry ◽  
Improve Device ◽  
Joining Process

The microelectronics industry is being continually challenged to decrease package size, lower power consumption and improve device performance for the mobile communication and server markets. In order to keep pace with these requirements, device manufacturers and assembly companies are focused on developing 3D-TSV integration schemes that will require stacking of 50 um thinned wafers with gaps of 15 microns or less. While conventional underfill approaches have been demonstrated for chip to chip and chip to wafer schemes, new materials and processes are required for wafer to wafer bonding given the target bondline and wafer handling issues. Photopatternable, low temperature curable dielectrics offer a potential solution to solve the issues by eliminating the need for flow and material entrapment during the joining process. This should result in a simplified bonding process that enables wafer to wafer bonding with improved device reliability. In this work, we will focus on validating the critical steps including patterning and bonding that are required to demonstrate the utility of this process using an aqueous developable benzocyclobutene based photodielectric material.

Robust Reliability Performance of Large size eWLB (Fan-out WLP)

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 001438-001457 ◽  
Author(s):  
Seung Wook Yoon
Keyword(s):  
Form Factor ◽  
Dielectric Materials ◽  
Structural Defects ◽  
Temperature Cycle ◽  
Wafer Level ◽  
Component Level ◽  
Wafer Level Packaging ◽  
Large Size ◽  
Reliability Performance ◽  
Robust Reliability

With reducing form-factor and functional integration of mobile devices, Wafer Level Packaging (WLP) is attractive packaging technology with many advantages in comparison to standard Ball Grid Array (BGA) packages. With the advancement of various fan-out WLP, it is more optimal and promising solution compared to fan-in WLP, because it can offer greater flexibility in design of more IOs, multi-chips, heterogeneous integration and 3D SiP. eWLB (embedded wafer level packaging) is a type of fan-out WLP enabling applications that require smaller form-factor, excellent heat dissipations, thin package profile as it has the potential to evolve in various configurations with proven manufacturing capacity and production yield. This paper discusses the recent advancements of robust reliability performance of large size eWLB. It will also highlight the recent achievement of enhanced component level reliability with advanced dielectric materials. After a parametric study and mechanical simulations, new advanced materials were selected and applied to eWLB. Standard JEDEC tests were carried out to investigate component level reliability of large size (9x9~14x14mm2) test vehicles and both destructive/non-destructive analysis were performed to investigate potential structural defects. Daisychain test vehicles were also tested for drop and TCoB (Temperature Cycle on Board) reliability performance in industry standard test conditions. Besides, this paper will also present a study of package level warpage behaviour with Thermo-Moire measurement.

Metal Wafer Bonding for MEMS Applications

2008 ◽  
Vol 1139 ◽  
Author(s):  
Viorel Dragoi ◽  
Gerald Mittendorfer ◽  
Franz Murauer ◽  
Erkan Cakmak ◽  
Eric Pabo
Keyword(s):  
Intermetallic Compound ◽  
Eutectic Alloy ◽  
Wafer Bonding ◽  
Alloy Layer ◽  
Manufacturing Processes ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Metal Diffusion ◽  
Metal Layers ◽  
Different Levels

AbstractMetal layers can be used as bonding layers at wafer-level in MEMS manufacturing processes for device assembly as well as just for electrical integration of different levels. One has to distinguish between two main types of processes: metal diffusion bonding and bonding with formation of an interface eutectic alloy layer or an intermetallic compound. The different process principles determine also the applications area for each. From electrical interconnections to wafer-level packaging (with emphasis on vacuum packaging) metal wafer bonding is a very important technology in MEMS manufacturing processes.

Enabling Resist Processing Technologies for Advanced Packaging

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 000830-000862 ◽  
Author(s):  
Antun Peic ◽  
Thorsten Matthias ◽  
Johanna Bartl ◽  
Paul Lindner
Keyword(s):  
Three Dimensional ◽  
Design Solution ◽  
Wafer Level ◽  
Coating Technology ◽  
3D Ic ◽  
Wafer Level Packaging ◽  
Aspect Ratios ◽  
Integration Schemes ◽  
Interconnect Design ◽  
Deep Cavities

The increasing adoption of advanced wafer-level packaging (WLP) technologies and high density interposer concepts clearly reflect the permanent need for form factor reduction, smaller process geometries and higher-count I/O on ICs. Currently, several strategies are being pursued to achieve these goals. The most promising approaches are summarized under the concept of three-dimensional integrated circuits (3D-IC) and three-dimensional wafer level packaging (3D-WLP) technology. A key component for 3D device integration schemes is the requirement of vertical through-silicon-via (TSV) interconnections that enables electrical through-chip communication through stacks of vertically integrated layers on the wafer scale. Ultimately, the use of TSVs also enables higher performance and smaller package sizes. In order to realize TSV connections, a series of process steps is required such as the thinning and bonding of the wafer to a carrier prior to the formation of through-wafer vias, followed by the passivation and metallization of the vias. Despite the potential benefits associated with the integration of TSVs also significant challenges have to be overcome. One of the greatest challenges for present and even more for upcoming TSV design strategies still remains the processing of photoresist and other functional polymers at and within TSV geometries. To this day, it is still very difficult to achieve a conformal polymer coating in deep cavities, along steep side walls and especially within the extreme aspect ratios of TSV. Mainly this is due to the fact that standard surface coating methods such as spin coating were just not developed to meet the requirements posed by these high aspect ratio microstructures. New and innovative approaches are needed to meet these new challenges. Spray coating is one of the most promising technologies to overcome current barriers. However, even most of the available spray deposition equipment is facing its limits with steadily decreasing via diameters and increasing aspect ratios on the other hand. Successively, the multitude of these challenging technological developments in the 3D-IC and wafer-level packaging area has created the demand for innovative manufacturing approaches, new equipment and related tools. Herein we present our new EVG ®NanoSprayTM coating technology with unique capabilities to overcome the present limits of conformal resist coating over extreme topography. We demonstrate one particularly promising application for conformal polymer coatings; as an annular lining at the interface between the conducting metal filling in the TSV and the silicon wafer. The intrinsic properties of the polymer allow a TSV design solution that is more forgiving on coefficient of thermal expansion (CTE) mismatch-induced stress between the silicon substrate and the interfacing metal. Consequently, this new type of polymer buffered TSV interconnect design promises to significantly reduce thermal stress-induced TSV delamination as one of the dominant failure modes for 3-D interconnects. We further demonstrate the application of EVG ®NanoSprayTM as enabling coating technology for llithographic processing of conformal coated TSVs. The patterning of thin photoresist layers at the bottom of vias and along the steep sidewalls of deep cavities allows for more degrees of freedom in electrical contact formation. The presented EVG ®NanoSprayTM coating technology opens new dimensions in advanced wafer level packaging and provokes reconsidering prevailing limitations in interconnect design.

Wafer Bonding Processes for the Manufacture of Microsystems

2008 ◽  
Author(s):  
Tony Rogers ◽  
Nick Aitken
Keyword(s):  
Bond Strength ◽  
Wafer Bonding ◽  
High Efficiency ◽  
Glass Frit ◽  
Acoustic Microscopy ◽  
Anodic Bonding ◽  
High Yield ◽  
Mems Devices ◽  
Wafer Level ◽  
Wafer Level Packaging

Wafer bonding is a widely used step in the manufacture of Microsystems, and serves several purposes: • Structural component of the MEMS device. • First level packaging. • Encapsulation of vacuum or controlled gas. In addition the technology is becoming more widely used in IC fabrication for wafer level packaging (WLP) and 3D integration. It is also widely used for the fabrication of micro fluidic structures and in the manufacture of high efficiency LED’s. Depending on the application, temperature constraints, material compatibility etc. different wafer bonding processes are available, each with their own benefits and drawbacks. This paper describes various wafer bonding processes that are applicable, not only to silicon, but other materials such as glass and quartz that are commonly used in MEMS devices. The process of selecting the most appropriate bonding process for the particular application is presented along with examples of anodic, glass frit, eutectic, direct, adhesive and thermo-compression bonding. The examples include appropriate metrology for bond strength and quality. The paper also addresses the benefits of being able to treat the wafer surfaces in-situ prior to bonding in order to improve yield and bond strength, and also discusses equipment requirements for achieving high yield wafer bonding, along with high precision alignment accuracy, good force and temperature uniformity, high wafer throughput, etc. Some common problems that can affect yield are identified and discussed. These include local temperature variations, that can occur with anodic bonding, and how to eliminate them; how to cope with materials of different thermal expansion coefficient; how best to deal with out-gassing and achieve vacuum encapsulation; and procedures for multi-stacking wafers of differing thicknesses. The presentation includes infra-red and scanning acoustic microscopy images of various bond types, plus some examples of what can go wrong if the correct manufacturing protocol is not maintained.

300mm Large Scale eWLB(embedded Wafer Level BGA) : Cost Effective Solution with Performance

2011 ◽  
Vol 2011 (DPC) ◽  
pp. 001046-001070
Author(s):  
Seung Wook Yoon ◽  
Yaojian Lin ◽  
Pandi C. Marimuthu ◽  
Yeong J. Lee
Keyword(s):  
Large Scale ◽  
Low Cost ◽  
Cost Effective ◽  
Batch Process ◽  
Dielectric Materials ◽  
Design Parameters ◽  
Wafer Level ◽  
Molding Compound ◽  
Package Size ◽  
Chip Size

Demand for Wafer Level Package (WLP) is being driven by the need to shrink package size and height, simplify the supply chain and provide a lower overall cost by using the infrastructure of a batch process. The increasing demand for new and more advanced electronic products with smaller form factor, superior functionality and performance is driving the integration of functionality into the third dimension. There are some restrictions in possible applications for fan-in WLPs since global chip trends tend toward smaller chip areas with an increasing number of interconnects. The shrinkage of the pitches and pads at the chip to package interface is happening much faster than the shrinkage at the package to board interface. This interconnection gap requires fan-out packaging, where the package size is larger than the chip size in order to provide a sufficient area to accommodate the 2nd level interconnects. eWLB is a type of fan-out WLP that has the potential to realize any number of interconnects with standard pitches at any shrink stage of the wafer node technology. 200mm eWLB is in HVM from industry last three years and there was need to move 300mm for scaling-up and low-cost solutions. This paper will highlight some of the recent advancements in large scale 300mm eWLB development. Compared to 200mm case, 300mm has more warpage and process issues due to its area increase. Thermo-mechanical simulation shows 100~150% more warpage with 300mm compared to 200mm. So various design parameters were studied to optimized warpage, such as dielectric materials and thickness, molding compound thickness etc. This paper presents study of process optimization for 300mm eWLB and mechanical characterization, reliability data including component/board level, challenges encountered and overcome, and future steps of scalability for higher throughput and manufacturability.

Self Priming Low Stress Aqueous Developable Benzocyclobutene (AD-BCB) Photodielectric Materials for Advanced Wafer Level Packaging

2015 ◽  
Vol 2015 (DPC) ◽  
pp. 000679-000697
Author(s):  
Hua Dong ◽  
Greg Prokopowicz ◽  
Bob Barr ◽  
Joe Lachowski ◽  
Jeff Calvert ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
High Reliability ◽  
Semiconductor Industry ◽  
Dielectric Materials ◽  
Film Stress ◽  
Wafer Level ◽  
Adhesion Promoter ◽  
Molding Compound ◽  
Wafer Level Packaging ◽  
New Formulation

As the semiconductor industry drives to more functionality in smaller and lighter devices, it requires new materials to meet the changing requirements of new and more advanced chip designs and packaging solutions. Photoimagable polymeric dielectric materials are a key building block for wafer level packaging (WLP); these include polyimide (PI), polybenzoxazole (PBO), acrylics, silicones, epoxy-phenolics and benzocyclobutene (BCB). Because of low copper diffusion, low temperature curing, high reliability and low moisture adsorption, BCB was the platform chosen for modification. In this work, we will focus on the development of self priming, low stress, aqueous developable version of BCB, known as AD-BCB. This new photodielectric material has improved mechanical properties of <25MPa film stress value and >28% elongation while maintaining good post develop and post cure adhesion on various substrates including silicon, silicon oxide, silicon nitride, copper, aluminum and epoxy molding compound. Elongation is significantly increased for this positive tone, aqueous developable, photodielectric materials, while film stress and wafer bow are significantly reduced. In addition, this new formulation is self priming and does not require a spin-on adhesion promoter. The material can be cured at as low as 200 °C with lithographic feature size of <10 μm and dielectric constant of 3.0.

Evolution of Wafer Bonding Technology and Applications from Wafer-Level Packaging to Micro/Nanofluidics-Enhanced Sensing

2021 ◽  
pp. 187-215
Author(s):  
Jikai Xu ◽  
Zhihao Ren ◽  
Bowei Dong ◽  
Chenxi Wang ◽  
Yanhong Tian ◽  
...  
Keyword(s):  
Wafer Bonding ◽  
Wafer Level ◽  
Wafer Level Packaging ◽  
Bonding Technology

3D Process Integration – Wafer-to-Wafer and Chip-to-Wafer Bonding

2006 ◽  
Vol 970 ◽  
Author(s):  
Thorsten Matthias ◽  
Markus Wimplinger ◽  
Stefan Pargfrieder ◽  
Paul Lindner
Keyword(s):  
Wafer Bonding ◽  
Process Integration ◽  
Logic Device ◽  
Wafer Level ◽  
Integration Schemes ◽  
Research Level ◽  
Rf Devices ◽  
Manufacturing Technologies ◽  
The Individual ◽  
3D Chip Stacking

ABSTRACTMany feasibility and design studies during the last years have shown that devices based on 3D chip stacking and integration can significantly outperform traditional planar (2D) devices. Furthermore, as packaging of the devices is a major cost factor, the possibility to integrate multiple functional entities in one package offers a huge potential for cost reduction. On research level the technical feasibility has been proven for a variety of processes. Today's focus lies on innovative manufacturing technologies and process integration schemes, which meet both, the economic and the technical demands.Stacking of individual chips (both chip-to-wafer and wafer-to-wafer) has the inherent advantage that different functional subsystems like logic and memory can be processed on separate wafers thereby reducing the complexity and the number of process steps greatly. The individual chips can be processed on heterogeneous materials, in different fabs and by different producers.Wafer-level integration has the advantage of higher throughput, enhanced cleanliness and the flexibility that standard fab equipment can be used for further processing. 3D integration applying chip-to-wafer bonding focuses on the yield (“good known die”) and enables to stack dies of different size e.g. several small dies on one big base die. This allows e.g. the integration of a logic device from a 300mm Si wafer with RF devices from a 150mm GaAs wafer.In this paper a higher emphasis lies on the key enabling manufacturing technologies and supported processes.

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