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Showing papers on "Electronic packaging published in 1993"


Journal ArticleDOI
John S. Corbin1
TL;DR: Finite element analysis is used to characterize the plastic strains that develop in the SBC interconnection during thermal cycling and identify an optimally reliable structure that is robust in terms of assembly-process variables.
Abstract: Solder Ball Connect (SBC) is a second-level surface mount electronics packaging technology in which ceramic modules containing one or more chips are joined to a circuit card (FR-4) by means of an array of nonhomogeneous solder columns. These columns consist of a high-temperature-melting 90%Pb/lO%Sn solder sphere attached to the module and card with eutectic solder fillets. The solder structures accommodate the bulk of the strain (which is due to the thermal-expansion mismatch between FR-4 and the 9211 ceramic of the modules) generated during power cycling. If the solder structures are not properly designed, the thermal strain can be a source of premature fatigue failure. In this work, finite element analysis is used to characterize the plastic strains that develop in the SBC interconnection during thermal cycling. Since plastic strain is a dominant parameter that influences low-cycle fatigue, it is used as a basis of comparison for various structural alternatives. Designed experiment techniques are used to systematically evaluate the thermal strain sensitivity to structural variables. Results are used to identify an optimally reliable structure that is robust in terms of assembly-process variables.

95 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of an area ratio, defined as ratio of the total channel cross-sectional area to the dividing flow header crosssectional area, on the coolant distribution in a parallel flow manifold was studied numerically for a Reynolds number of 50, a typical flow condition observed in electronic packaging.

67 citations



Patent
Yi-Hsin Pao1
12 Nov 1993
TL;DR: In this paper, a novel printed circuit board with a high density of circuit components has been described, where lower circuit components reside within recesses in a printed wiring board and upper circuit components residing above the lower circuit component.
Abstract: A novel printed circuit board is disclosed. The printed circuit board has a high density of circuit components with lower circuit components residing within recesses in a printed wiring board and upper circuit components residing above the lower circuit components.

45 citations


Patent
04 Oct 1993
TL;DR: In this article, an elastomeric interposer is constructed from a thermally conductive material such as diamond and a heat dissipation means is thermally connected to the edges of the substrate to extract heat generated within the structure.
Abstract: of EP0593966The present invention is directed to a structure (2) for packaging electronic devices, such as semiconductor chips (36, 38), in a three dimensional structure which permits electrical signals to propagate both horizontally and vertically. The structure is formed from a plurality of assemblies (4, 6). Each assembly is formed from a substrate (8) having disposed on at least one surface a plurality of electronic devices. Each assembly is disposed in a stack of adjacent assemblies. Between adjacent assemblies there is an electrical interconnection means (49) electrically interconnecting each assembly. The electrical interconnection means is formed from an elastomeric interposer. The elastomeric interposer is formed from an elastomeric material having a plurality of electrical conductors extending therethrough, either in a clustered or un-clustered arrangement. The electrical interconnection means is fabricated having a plurality of apertures extending therethrough. The array of apertures corresponds to the array of electronic devices on the substrates. The aperture and electrical interconnection means is disposed over the array of electronic devices so that the electrical interconnection means is between adjacent electronic devices. The stack of assemblies is compressed thereby compressing the electrical interconnection means between adjacent assemblies. The substrate of each assembly is formed from a thermally conductive material such as diamond. A heat dissipation means is thermally connected to the edges of the substrate to extract heat generated within the structure. Methods for fabricating the electrical interconnection means as a stand alone elastomeric sheet are described. The ends (50, 54) of the plurality of conductors in the electrical interconnection means (49) are fabricated so that upon compression between adjacent assemblies (4, 6) there is a wiping action between the conductor ends (e.g. 50) and contact locations (e.g. 30) on the adjacent assemblies to form a good electrical contact therewith.

26 citations


Patent
05 Apr 1993
TL;DR: In this paper, a composite having a graphite matrix is infiltrated with a metal or a metal alloy and the external surfaces of the composite then coated with a metallic layer to provide environmental and mechanical protection.
Abstract: There is provided a component for use in electronic packaging. The component is a composite having a graphite matrix which is infiltrated with a metal or a metal alloy and the external surfaces of the composite then coated with a metallic layer to provide environmental and mechanical protection. The packaging components are lightweight, have a coefficient of thermal expansion close to that of a silicon based integrated circuit device and further, have a high coefficient of thermal conductivity.

22 citations


Book
01 Feb 1993
TL;DR: The Electronic Packaging, Microelectronics and Interconnection Dictionary (EPID) as discussed by the authors is an extensive collection of terms and acronyms that comprise the language of modern electronics.
Abstract: A dictionary focusing on the multidisciplinary field of electronic packaging, this work features an extensive collection of terms and acronyms that comprise the language of modern electronics. From circuits and communication systems to all types of electronic subsystems and assemblies, this reference includes up-to-date entries and clear, concise definitions for more than 6000 terms, acronyms, abbreviations and symbols that are commonly encountered by everyone working in the industry - regardless of their area of expertise. The "Dictionary" covers the full range of high-performance electronic systems, including microelectronics, electronic packaging, materials, components, and much more. Rapidly changing technology and the need for communication in a highly multidisciplinary field make the "Electronic Packaging, Microelectronics and Interconnection Dictionary" a valuable desk reference for electronics, electrical, mechanical and materials engineers, as well as everyone else working in the electronic packaging field.

19 citations


Patent
30 Jun 1993
TL;DR: In this paper, a potted plant is sorted according to a grade, placed in a decorative cover, and then automatically deposited into a protective sleeve, ready for containment within a shipping carton.
Abstract: The present invention is a modular system for packaging articles for shipment. In particular, a potted plant is sorted according to a grade, placed in a decorative cover, then automatically deposited into a protective sleeve. The potted plant thus packaged is ready for containment within a shipping carton. Various components of the system may be adapted for various packaging needs and circumstances.

17 citations


Patent
14 Jun 1993
TL;DR: In this article, a method and package for protecting an electronic component from the environment comprises providing at least one bag (22) made from thermoplastic heat shrink material, inserting the electronic component (10) into the bag, injecting a liquid polymerizable resin (38), heating the bag and then curing the resin.
Abstract: A method and package for protecting an electronic component (10) from the environment comprises providing at least one bag (22) made from thermoplastic heat shrink material, inserting the electronic component (10) into the bag (22), injecting a liquid polymerizable resin (38) into the bag (22), heating the bag (22) to shrink it about the electronic component (10) and the resin (38), and curing the resin (38). Precalculated shrink of the thermoplastic wrap over a measured amount of resin (38) results in minimum material usage, and in a light weight, self tooled, rigid assembly. The resulting cured shape of the molded self tooled assembly will be largely determined by the shape of the electronic circuit components (16, 18, 20) mounted to the electronic component (10). Thus, the final cured shape need not be governed or altered by subsequent tooling or processing. Conductive shielding around the electronic components is provided between a plurality of layers, or bags, of shrink wrap.

14 citations


Journal ArticleDOI
01 Jun 1993
TL;DR: The MQUAD as discussed by the authors is a high performance reliable technology currently in use for packaging of microprocessors, high speed ASIC devices, including CMOS, Bi CMOS and Bi polar, gallium arsenide, and other high performance IC's.
Abstract: This paper describes the design and development of MQUAD technology. The MQUAD packaging system is a high performance reliable technology currently in use for packaging of microprocessors, high-speed ASIC devices, including CMOS, Bi CMOS, Bi polar, gallium arsenide, and other high performance IC's. The packaging technology is being used for devices dissipating up to 14 watts and switching speed of up to 300 MHz. The design and development was carried out with the objectives of high thermal performance (up to 15 watts), high electrical performance (inductance and capacitances lower than comparable PQFPs) and reliability superior to the PQFPs. The approach taken was; to use an adhesively bonded metal package. An aluminum alloy lid and base were chosen to give excellent heat dissipation ability, mechanical integrity and light weight construction. A special anodization process was developed to put a hard, electrically insulating black colored anodic film on the aluminum alloy components. The adhesive seal is a filled epoxy having low dielectric constant and low ionic content and with excellent adhesion to both copper alloys and aluminum anodic films, especially in moist environments. The leadframe chosen is a high-strength, thermally conductive copper alloy. The assembly process for the MQUAD package emulates the PQFP assembly process except that the molding step is replaced by a single step pad attach simultaneous with the seal adhesive lamination/cure process. The leadframe pad is attached to the anodized aluminum alloy base via a silver-filled epoxy paste. The package was thoroughly tested for reliability and fully characterized for thermal and electrical performance. Reliability tests performed include temperature cycling, thermal shocks, solvent resistance, flammability, pressure cooker, and vapor phase shocks. Reliability of MQUAD packages is superior to that of PQFPs. Characterization includes /spl theta//sub ja/ and /spl theta//sub jc/, and resistance, inductance and capacitance measurements. Thermal and electrical performance of MQUAD packages equal or exceed that of comparable plastic or ceramic QFPs. The high reliability and performance of MQUAD was confirmed by many customers and users and has been published. Because of these benefits, the technology is being further extended to advanced packages such as MCMs, TAB and ball or pad grid arrays. >

13 citations



Journal ArticleDOI
TL;DR: In this paper, the principles of laser resistor trimming, laser types used, trimming techniques, and technology trends are described. But laser cutting of ceramics in such applications as electronic packaging and the use of lasers to pattern thin films are also discussed.
Abstract: Laser resistor trimming, an effective tool for producing accurate and reliable electrical elements is discussed. Laser trimming has minimum effect on power handling capability; element value variation with time, temperature, and voltage; and electrical noise. The principles of laser trimming, laser types used, trimming techniques, and technology trends are described. Laser cutting of ceramics in such applications as electronic packaging and the use of lasers to pattern thin films are also discussed. >

Book ChapterDOI
01 Jan 1993
TL;DR: In this paper, the authors have discussed the wetting behavior of near-eutectic Sn-Pb solders and the applications where the properties of these alloys can be improved.
Abstract: Previous chapters of this book have discussed the wetting behavior of near-eutectic Sn-Pb solders. These alloys are the most common in electronic applications and are deserving of the greatest attention. However, there are many applications where the properties of these alloys can be improved. A composite solder, or a solder that contains second-phase dispersions of particles, could improve solder joint properties. The area where composite solders could have the greatest impact is in improving the mechanical properties of the joint. However, the wetting behavior of the solder cannot be compromised for the sake of the mechanical properties -good wetting behavior is a necessity. Therefore, for a composite solder to be useful for electronic packaging applications mechanical properties, wetting and manufacturability must be optimized.

Proceedings ArticleDOI
09 May 1993
TL;DR: An introduction to current research in computer-aided design and packaging for optoelectronic systems utilizing free space optical interconnects and recent work involving double-sided alignment of a single substrate as well as alignment techniques between two different substrates is discussed.
Abstract: An introduction to current research in computer-aided design (CAD) and packaging for optoelectronic systems utilizing free space optical interconnects is presented. New CAD tools are presented that allow layout of multistage networks based on CGH fabrication limitations and the subsequent synthesis of the interconnect holograms. Recent work involving double-sided alignment of a single substrate as well as alignment techniques between two different substrates is discussed. Several packaged systems utilizing photorefractive crystals to minimize alignment problems are also presented.

Journal ArticleDOI
John J. Glatz1, D.L. Vrable1
TL;DR: This paper will identify candidate advanced materials, and present component design alternatives associated with the new materials and their potential performance improvement, and conclude with an assessment of the impact of the TM materials on the performance of a candidate component.

Proceedings ArticleDOI
01 Jun 1993
TL;DR: The ELASTICON connector as mentioned in this paper is a new high performance elastomeric connector that was developed to address some of the key limitations of existing MCM and land grid array connectors.
Abstract: Elastomeric connectors are a relatively new technology compared with conventional connector systems. A wide variety of elastomeric connectors are available today to meet the interconnection requirements for many different electronic packaging applications. Multichip modules are one of the many applications that benefit from the high density interconnection capabilities of elastomeric connectors. The ELASTICON connector is a new high performance elastomeric connector that was developed to address some of the key limitations of existing MCM and land grid array connectors. The ELASTICON connector uses gold or gold alloy wires for the conductive elements embedded in an elastomer material. The size, shape and spacing along with the elastomer material properties can be tailored to specific application requirements. The processes that have been developed for fabricating the ELASTICON connector represent a new direction for elastomeric connector manufacturing. Besides LGA packaging applications, ELASTICON connectors can be used for board-to-board and cable-to-board interconnections as well as high density PCB and IC chip testing applications. >

Proceedings ArticleDOI
01 Jun 1993
TL;DR: In this article, the effects of packaging stresses on offset voltage shift in a precision operational amplifier are discussed, and experiments are conducted to reduce the effect of such stresses on the die surface where active device elements are located.
Abstract: In molded DIP packaging die attach stresses and stresses due to the contraction of the molding compound lead to a complex state of stress on the die surface where active device elements are located. This paper summarizes experimentation to reduce the effects of packaging stresses upon offset voltage shift in a precision operational amplifier. Variables examined include circuit location, low stress mold compounds, silicone gel coatings, side braze versus molded DIP assembly and post assembly trim. >

Proceedings ArticleDOI
You-Wen Yau1, D.C. Long1, W.T. Grant1, N.S. Sandhu1, J.J. Fulton1 
01 Jun 1993
TL;DR: In this paper, an overview of various via forming technologies along with a comparison of their capability and flexibility is given, focusing on mechanical punching, laser drilling, and electron beam machining.
Abstract: Via hole formation plays an important role in multi-layer electronic packaging fabrication because it provides vertical paths for the packaging interconnection networks. As the packaging wiring density and complexity increases, additional and more stringent demands are put on the via formation technology (e.g. tighter dimensional control, higher via positional accuracy, etc.). Over the years, several via formation technologies have been developed and implemented for manufacturing high performance electronic packages. They range from the traditional mechanical punch to the state-of-the-art directed energy technologies such as laser and electron beam. The primary driving forces for the various via formation technologies are application extension, performance enhancement, cost reduction, and flexibility. In this paper, an-overview of these via forming technologies along with the comparison of their capability and flexibility is given. The focus is on mechanical punching, laser drilling, and electron beam machining. >

Book ChapterDOI
01 Jan 1993
TL;DR: In this paper, the authors consider the thermal stress in the die-bonding layer of a die-attached semiconductor device and the resulting thermal expansion mismatch among the die, the bonding material, and the package.
Abstract: An important aspect of packaging the semiconductor device is how securely the die is attached to the substrate. The chip is normally bonded onto a substrate or a package using hard solder, soft solder, metal-filled epoxy, or glass.1–3 The package together with the die-bonding layer serves the purposes of heat dissipation, mechanical support, and sometimes electrical conduction. With increasing power requirements of the chip, quality die-attach becomes a special concern. Thermal stress considerations need to be taken into account even in a perfectly executed die-attach where the constituent materials have formed a single entity with no voids. Due to thermal expansion mismatch among the die, the bonding material, and the package, stress is introduced in the cooling step of the bonding process. Stress is generated in the die that may cause cracking. Dynamic stress is also produced in the bonded devices when they are subjected to power cycling, thermal cycling, or thermal shock.


Patent
26 Oct 1993
TL;DR: In this paper, a high density interconnect land grid array package device combines various electronic packaging techniques in a unique way to create a very thin, electrically and thermally high performance package for single or multiple semiconductor devices.
Abstract: A high density interconnect land grid array package device combines various electronic packaging techniques in a unique way to create a very thin, electrically and thermally high performance package for single or multiple semiconductor devices. A thin and mechanically stable substrate or packaging material (12) is selected that also has high thermal conductivity. Cavities (14) in the substrate or packaging material (12) accommodate one or more semiconductor devices that are attached directly to the substrate or packaging material. At least one of said semiconductor devices includes at least one optical receiver and/or transmitter. A thin film overlay (18) having multiple layers interconnects the one or more semiconductor devices to an array of pads (20) on a surface of the thin film overlay facing away from the substrate or packaging material. Solder balls (22), conductive adhesive or elastomeric connectors are attached to the pads to provide direct electrical and mechanical attachment means to other system hardware. In one embodiment of the invention, the optical receiver and/or transmitter receives and/or transmits light signals through the thin film overlay. In another embodiment of the invention, the optical receiver and/or transmitter receives and/or transmits light signals through holes (47) formed through the thin film overlay. The holes may be back filled with an optical quality material.

Patent
28 Jul 1993
TL;DR: In this paper, a simple format change is carried out in a simple way by bringing the set (40, 41) required for the particular size of the pack into the packaging position as a result of a rotational or other movement.
Abstract: Apparatus (packaging machine) for the packaging of articles of differing size. In packaging technology, it is often necessary to solve the problem of producing packs of differing size on one and the same packaging machine. As a rule, adapting this to the different pack formats requires considerable conversion work. This in turn involves lengthy standstill phases of the packaging machine. To make it easier for the packaging machine to be changed over to different pack formats, packaging members, especially folding members, critical for the packaging process are provided in the form of a plurality of, preferably two sets (40, 41). A particular set of packaging members is in the packaging position (43). A further (part) set is in an exchange position (44) for the exchange of individual or all packaging members for other formats. The format change is carried out in a simple way by bringing the set (40, 41) required for the particular size of the pack into the packaging position (43) as a result of a rotational or other movement. The standstill times of the packaging machine necessary for a format change are consequently minimal.

Proceedings ArticleDOI
24 May 1993
TL;DR: In this article, a low temperature co-fired ceramic on metal (LTCC-M) multilayer circuit board technology intended for dual-use by both the military and commercial market sectors is described.
Abstract: A novel, low temperature co-fired ceramic on metal (LTCC-M) multilayer circuit board technology intended for dual-use by both the military and commercial market sectors is described in this paper. This technology has been optimized for low cost, high circuit density multichip modules and board level integration. Limitations of the present low-temperature co-fired ceramic systems have been overcome by using a metal core in the LTCC-M technology. This technology readily allows the design of rugged, yet lightweight, electronic modules. In addition, the co-fired metal core permits this technology to be readily scaleable in terms of circuit density, size, and power dissipation; thereby making this an excellent candidate for a dual-use technology. Several advanced military packaging applications are pointed out in this paper. >

Journal ArticleDOI
TL;DR: In this paper, a self-contained frequency-modulation continuous-wave (FMCW) radar incorporating a compact 2.2-ns broadband superconducting delay line operating at 80 K has been developed.
Abstract: A self-contained frequency-modulation continuous-wave (FMCW) radar incorporating a compact 2.2-ns broadband superconducting delay line operating at 80 K has been developed. The authors note that this is the first demonstration of an integral microwave system utilizing high-temperature superconductor (HTSC) circuitry incorporating a closed-cycle cooler and a long-life permanently sealed dewar. They discuss development efforts focused on high-frequency packaging techniques compatible with the stringent thermal and electrical performance requirements of HTSC microwave circuitry. They also review the prospects for development of low-cost and reliable closed-cycle cryogenic coolers in the 2-10-W size range. >

Proceedings ArticleDOI
12 Nov 1993
TL;DR: In this article, the nature of graphite fibers, the translation of fiber properties into composites including metal, organic, and carbon matrix, and applications for the resulting high thermal conductivity composites are discussed.
Abstract: Thermal management has become a limiting problem for both military and commercial systems. High thermal conductivity graphite fibers provide a breakthrough in the efficiency of conductive cooling. The fibers also have exceedingly high specific modulus and a negative coefficient of thermal expansion; these properties can be used to tailor the thermal expansion of composite materials to virtually any required level. This paper discusses the nature of the fibers, the translation of fiber properties into composites including metal, organic, and carbon matrix. Emphasis is on applications for the resulting high thermal conductivity composites. These applications include electronic packaging, aircraft, and spacecraft.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.


Book ChapterDOI
01 Jan 1993
TL;DR: In the design of electronics packaging systems, there is rarely a single “best” solution; the final design is usually a tradeoff between different performance attributes (system speed, thermal constraints or size) and cost.
Abstract: In the design of electronics packaging systems, there is rarely a single “best” solution; the final design is usually a tradeoff between different performance attributes (system speed, thermal constraints or size) and cost. In many cases, tradeoffs between cost and performance are the most important. Unfortunately, the analysis of cost and performance tradeoffs is a very complex task. On the performance end, the vast variety of design options available today to the packaging engineer precludes an exhaustive analysis of all viable alternatives. On the cost end, the treatment usually is even more cursory because of the complexity and uncertainty of cost before actual production.

Proceedings ArticleDOI
L.X. Lu1, C. Wu1, J. Litva1
20 Oct 1993
TL;DR: The 3D-FDTD software package can be used to simulate electronic packaging problems from an electromagnetic field point of view and is an accurate and flexible technique to simulate complex electromagnetic problems.
Abstract: It has been shown that the finite difference time domain (FDTD) method is an accurate and flexible technique to simulate complex electromagnetic problems. A 3D-FDTD software package is introduced. It can be used to simulate electronic packaging problems from an electromagnetic field point of view. >


Journal ArticleDOI
TL;DR: In this article, the authors present a mass manufacturable AIN-based package tailored to high-level automotive electronics applications. The package design is unique in that it provides for the total separation of the electrical signal conduction from the mechanical support/mounting functions of the package.
Abstract: The advent of novel advanced packaging technologies such as multilayer thin‐film interconnect, combined with continuous improvements in IC clock speed and circuit performance, has placed extreme demands on electronics packaging and package materials. Aluminium nitride (AIN) ceramic offers significant opportunities and advantages for package design, particularly where the effective thermal management and overall reliability of large devices are a high priority. AIN has already been successfully employed at the substrate level for the enhanced thermal relief of power devices. Examples of these applications include heat sinks and device mounts for thyristor modules, power transistors, solid state relays, power SCRs, switching modules, LEDs and various RF package configurations. Both bare and metallised AIN substrates are beginning to find application as a substitute for beryllia (BeO) in mass market and high reliability automotive electronics applications. Successfully implementing AIN in a high level electronics packaging application requires a systems approach in which the intrinsic properties of AIN are considered as ‘first principles’ in shaping the package design process. The unique physicochemical and mechanical properties of AIN require the development of specialised metallisation and co‐firing processes to fabricate the advanced components necessary for hermetic packaging of complex devices and multichip modules. This paper presents a practical and mass manufacturable AIN‐based package tailored to these high level applications. The package design is unique in that it provides for the total separation of the electrical‐signal conduction from the mechanical support/mounting functions of the package. Such a separation of the functions improves both the package durability and reliability relative to currently available electronics packages of conventional designs.