Utilizing 3D Package Technology for Complex SiP Applications - Innovative Solutions for System Level Integration and Miniaturization

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Hand-held communication and entertainment products continue to dominate the consumer markets worldwide,and with each
generation,companies are offering more and more features and/or capability. Even though the actual functionality of the new
product offering expands,the customer is expecting each generation to be smaller and lighter that its predecessor. More
functionality typically requires additional or more complex electronics and greater memory capacity. Increasing functional
capability,however,can adversely impact the products size as well as manufacturing cost. The challenge manufactures face
when competing in the world marketplace is to offer a product that will meet all performance and functionality expectations
within budget and without increasing product size.
This paper will explores a number of system level applications developed within Tessera’s Package Engineering Service
Laboratories and examine the results of extensive computer modeling as well as review the data compiled from electrical
performance and physical stress testing.

Author(s)
Vern Solberg
Resource Type
Technical Paper
Event
IPC APEX EXPO 2005

RoHS Substance Thresholds,Facts and Friction

Meeting RoHS requirements is confusing at best. Currently,RoHS bans the presence of 6 substances,: Lead (Pb),Cadmium (Cd),Mercury (Hg),Hexavalent Chromium (Cr6+),Polybrominated biphenyl (PBB) and Polybrominated diphenylether (PBDE). As of 18 August 2005,the European Union (EU) amended the RoHS document with maximum concentration values (MCVs) of 1000 ppm for 5 of the substances; Pb,Hg,Cr6+,PBB & PBDE and 100 ppm for the 6th substance; Cd at the homogenous level. Other documents within the EU and member states have defined MCVs,but there is not total agreement between EU Directives and the member states on the maximum threshold values. With the delay of defined RoHS thresholds,other regions of the world are defining MCVs,but without universal agreement. Companies in the electrical and electronics equipment (EEE) industry are subsequently incorporating their understanding of MCVs into company specifications and requiring the suppliers to meet them.
What are the existing EU Directive requirements? How do they apply and what thresholds should be used for electrical and electronic products? This paper will discuss the RoHS 6 substances,thresholds as stated in the EU,common company defined threshold differences and the issues they cause. It is not all inclusive since laws and directives are constantly changing,evolving or being released.

Author(s)
Mark Frimann
Resource Type
Technical Paper
Event
IPC Fall Meetings 2005

Flexible Printed Boards

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This paper describes flexible printed circuit boards,used as “Product Boards” or “Interposers”,chip mounting structures. Traditionally,flexible circuit boards are made with polyimide dielectric cores. These are made either by lamination processes of a foil with adhesive,or the build-up of the copper from an “adhesiveless” process

Author(s)
Jack Fisher
Resource Type
Technical Paper
Event
IPC Fall Meetings 2004

Flex Based 3D Package Innovations for Enabling Low Cost System Level Integration and Miniaturization

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Hand-held communication and entertainment products continue to dominate the consumer markets worldwide and,with each generation,offering more and more features and/or capability. And even though the actual functionality of the new product offering expands,the customer is expecting each generation to be smaller and lighter that its predecessor. More functionality typically requires additional or more complex electronics and greater memory capacity. Increasing functional capability,however,can adversely impact the products size as well as manufacturing cost. The challenge manufactures face when competing in the world marketplace is to offer a product that will meet all performance and functionality expectations within budget and without increasing product size. Increased electronic functionality can be achieved through the development of more complex silicon integration (system-on-chip) but that route generally requires a great deal of capital resources and time. With the rapid deployment of new products from an ever growing number of competing companies’,time-to-market can be the difference between leading and following. For that reason,many manufacturers will rely heavily on more innovative IC package solutions,solutions for integrating a number of already proven functional elements within a single-package outline. When adapting multiple die configurations,each package becomes a fully tested subsystem that can be certified by the supplier before board or module level assembly. To achieve system level integration and miniaturization goals,companies’ can now rely on a combination of multiple-die package solutions and high-density flexible film based substrate methodology. For many applications,the multiple-die package is actually proving superior to the system-on-chip alternative because it minimizes risk and economically integrates several different but complementary functions. In the case of memory for example,multiples of the same function can be vertically stacked for increased density. This paper will explore three flexible film based multiple die system level applications developed within Tessera’s Package Engineering Service Laboratories.

Author(s)
Vern Solberg
Resource Type
Technical Paper
Event
IPC Fall Meetings 2004

Performance and Printing of Pb-Free Solder Paste for 100-micron Pitch Geometries

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Recent advances in chip technologies have prompted a rapid increase in the density of solder joints in electronic components. Further reductions in pitch are likely,leading to joint structures exhibiting sub 0.100mm (100µm) dimensions. EC legislation from mid 2006 bans the use of Pb,for most applications,in solders which means that next generation solder pastes will have to be Pb-free. One low cost assembly solution is stencil printing/wafer bumping of fine particle solder pastes. For ultra fine pitch applications this will present significant challenges and there is a requirement to understand the sub processes in stencil printing at ultra fine pitch. Paste roll; aperture filling/release; post print behavior and paste open time have been examined using fine particle Pb-free solder pastes,and solder paste rheology,particle size distribution,metal content,flux type and stencil aperture attributes have been investigated to provide ultra fine pitch solutions. In this paper we report that solder paste printing has been achieved at sub 100µm pitch using Pb-free solder paste with IPC type-6 (15-5µm) and type-7 (12-2µm) particle size distributions. For the type-6 paste,full array printing was achieved with 50µm deposits at 110µm pitch,and for peripheral printing patterns,60µm sized deposits at 90µm pitch. For type-7 paste sub 100µm pitch printing was achieved for full array patterns. The results satisfy the criterion that paste deposits can be produced at ultra fine pitch. Furthermore,subtle differences in the performance of type-6 and type-7 suggest that each is suitable for different specific application geometries. Reflow trials indicated that solderability of the small volumes depended heavily on reflow profile ramp rates and reflow atmosphere. Process models for introducing inert nitrogen reflow atmospheres are presented.

Author(s)
B. J. Toleno,G. J. Jackson,N. N. Ekere
Resource Type
Technical Paper
Event
IPC Fall Meetings 2004

Materials Information for Flex Designers and Fabricators

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A flexible circuit is more than just thin materials made into an interconnecting device. Understanding the characteristics of the materials and their properties versus circuit design type and requirements,are variables that circuit designers and fabricators should understand in order to build the best performing and cost effective alternatives for their customers. Sometimes the requirements of a design are only vaguely identified and the information requested from a materials supplier is not always the most applicable for the desired design and application. Over or under performance is designed in,requiring several iterations of building and testing to get to the most desired cost effective end result. Prototyping with one material type and then going to production with another material type also is cause of concern for the end user. Not all materials are the same,even when they are “generically” lump ed into groups for convenience sake.

Author(s)
Duane B. Mahnke
Resource Type
Technical Paper
Event
IPC Fall Meetings 2004

PWB Design: Beyond Copper Interconnects

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Two emerging board technologies,embedded passives and embedded optical waveguides,have the potential to change the way that printed wiring boards operate. No longer will interconnects be relegated to copper,but true passive electrical functionality will be incorporated into the board. Some high speed electrical interconnects may actually be replaced with pulses of light guided through transparent optical materials built into the board. These technologies are reviewed in simplified form,and the implications for board designers are examined.

Author(s)
Robert T. Croswell Ph.D.
Resource Type
Technical Paper
Event
IPC Fall Meetings 2004