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1 – 10 of 259
Article
Publication date: 1 April 1994

J.M. Morrison, T.G. Tessier and B. Gu

Recently, a Transverse Excited Atmospheric (TEA) CO2 laser technology has been developed for the micro‐machining of vias in non‐reinforced glass laminates. This system has been…

Abstract

Recently, a Transverse Excited Atmospheric (TEA) CO2 laser technology has been developed for the micro‐machining of vias in non‐reinforced glass laminates. This system has been designed to accommodate the large panel sizes associated with PWB processing. The salient features of this modified CO2 laser technology are summarised. A joint Lumonics/Motorola study was carried out to assess the applicability of this laser processing technology for use in higher density PWB and MCM‐L substrate processing and its compatibility with currently available classes of dielectrics used in high density interconnect applications. A 10x improvement in cycle time/throughput over the existing raster scanning laser ablation process has been demonstrated.

Details

Circuit World, vol. 21 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 February 1995

R. Fillion, R. Wojnarowski, T. Gorcyzca, E. Wildi and H. Cole

An innovative embedded chip MCM technology is being developed to address the packaging needs of the high volume, non‐military electronics industries. This development has evolved…

Abstract

An innovative embedded chip MCM technology is being developed to address the packaging needs of the high volume, non‐military electronics industries. This development has evolved out of the GE High Density Interconnect (HDI) embedded chip MCM technology that was aimed at very high performance electronics in harsh military environments. In the HDI process, multiple bare chips are placed into cavities formed in a ceramic substrate and interconnected using an overlay polymer film, thin film metallisation and laser formed vias. Multiple levels of fine line (20 to 40 microns) interconnections and reference planes are used to form the circuit. In this new process, a plastic encapsulated substrate is formed by moulding a polymer resin around the bare die after placement on to a flat polymer film pre‐coated with an adhesive layer. After curing of the resin, the circuit is formed by patterning via holes through the polymer film to the components, metallising the polymer film and patterning the metal into the desired interconnect pattern. Feature sizes are readily scaled to the complexity needed by the circuit, permitting the use of lower cost and higher yield board photopatterning processes and equipment. This paper will cover the development of this low cost technology and will describe the process. It will also describe the thermal, mechanical and electrical features of this process and show actual working prototype modules.

Details

Circuit World, vol. 21 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1992

B. Waterfield and Geoff Griffiths

At the Annual General Meeting of ISHM‐France, held on 12 June 1991, the following were elected:

Abstract

At the Annual General Meeting of ISHM‐France, held on 12 June 1991, the following were elected:

Details

Microelectronics International, vol. 9 no. 1
Type: Research Article
ISSN: 1356-5362

Content available
165

Abstract

Details

Microelectronics International, vol. 16 no. 2
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 1 June 2000

John H. Lau and Chris Chang

There are many advantages of microvia: it requires a much smaller pad, which saves the board size and weight; with microvia, more chips can be placed in less space or a smaller…

1658

Abstract

There are many advantages of microvia: it requires a much smaller pad, which saves the board size and weight; with microvia, more chips can be placed in less space or a smaller PCB, which results in a low cost; and with microvia, electrical performance improves due to a shorter pathway. Basically, there are five major processes for microvia formation: NC drilling; laser via fabrication including CO2 laser, YAG laser, and excimer; photo‐defined vias, wet or dry; etch via fabrications including chemical (wet) etching and plasma (dry) etching; and conductive ink formed vias, wet or dry. This paper will discuss the materials and processes of these five major microvia formation methods. At the end, eight key manufacturers from Japan will be briefly illustrated for their research status and current capability of producing smallest microvia.

Details

Circuit World, vol. 26 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 April 1993

P. Kersten, V. Glaw and H. Reichl

Multichip module packaging enables a significant increase of interconnect densities and performance of electronic systems. Multichip module technology based on laminate materials…

Abstract

Multichip module packaging enables a significant increase of interconnect densities and performance of electronic systems. Multichip module technology based on laminate materials (MCM‐L) is attractive due to low cost and use of the standard equipment used by PCB manufacturers. The most limiting factor for higher wiring densities in PCB technology is the mechanical drilling of plated‐through holes. Using 0.3 mm drill diameters, 0.5 mm land diameters are required, which limit the area for routing of tracks. Therefore, alternative dielectric materials, which can be structured photolithograpically, by plasma etching or laser drilling, are very attractive for MCM‐L technology. In this paper an epoxy resin layer, commercially available as a solder mask, is investigated as an interdielectric layer. Via hole drilling is investigated using an excimer laser. To show process feasibility, a two‐layer wiring system is fabricated using the excimer laser structured epoxy resin as an interdielectric layer on conventional epoxy board (FR‐4).

Details

Circuit World, vol. 20 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 December 1999

S. Zhang, J. De Baets and A. Van Calster

A flip chip on board technology fully compatible with current PCB facilities is reported. It used reflow soldering for chip attachment. It required electroless nickel/immersion…

Abstract

A flip chip on board technology fully compatible with current PCB facilities is reported. It used reflow soldering for chip attachment. It required electroless nickel/immersion gold finishing on the board pads as well as on the chip pads. A no‐clean solder paste was printed on the boards before chip placement. Thus, there was no requirement for solder deposition on the chip side. Assembly tests with various chip formats proved the feasibility of this technology. X‐ray inspection and cross‐sectioning revealed the good shape and alignment of the reflowed solder joints. The reliability of underfilled assemblies was studied by ‐40 to 125°C thermal cycling. This approach is especially suitable for prototype or low volume productions as it eliminates the solder bumping process on the chip side, which is usually performed on the wafer level.

Details

Microelectronics International, vol. 16 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 27 November 2023

Sanjaya C. Kuruppu, Markus J. Milne and Carol A. Tilt

This study aims to respond to calls for more research to understand how sustainability control systems (SCSs) feature (or do not feature) in short-term operational and long-term…

Abstract

Purpose

This study aims to respond to calls for more research to understand how sustainability control systems (SCSs) feature (or do not feature) in short-term operational and long-term strategic decision-making.

Design/methodology/approach

An in-depth case study of a large multinational organisation undertaking several rounds of sustainability reporting is presented. Data collection was extensive including 26 semi-structured interviews with a range of employees from senior management to facility employees, access to confidential reports and internal documents and attendance of company meetings, including an external stakeholder engagement meeting and the attendance of the company’s annual environmental meeting. A descriptive, analytical and explanatory analysis is performed on the case context (Pfister et al., 2022).

Findings

Simon’s (1995) levers of control framework structures our discussion. The case company has sophisticated and formalised diagnostic controls and strong belief and boundary systems. Conventional management controls and SCSs are used in short-term operational decision-making, although differences between financial imperatives and other aspects such as environmental concerns are difficult to reconcile. SCSs also provided information to justify company actions in short-term decisions that impacted stakeholders. However, SCSs played a very limited role in the long-term strategic decision. Tensions between social, environmental and economic factors are more reconcilable in the long-term strategic decision, where holistic risks and opportunities need to be fully identified. External reporting is seen in a “constraining” light (Tessier and Otley, 2012), and intentionally de-coupled from SCSs.

Originality/value

This paper responds to recent calls for rich, holistic and contextually-grounded perspectives of sustainability processes at an extractives company. The study provides novel insight into how SCSs are used (or not used) in short-term or long-term decision-making and external reporting. The paper illustrates how a large company is responding to sustainability pressures within the unique contextual setting of New Zealand. The study outlines the imitations of existing practice and provides implications for how sustainability-based internal controls can be better embedded into organisations.

Article
Publication date: 16 November 2019

Josep Bisbe, Anne-Marie Kruis and Paola Madini

Recent accounting research has connected the coercive and enabling types of formalisation (C/E) (Adler and Borys, 1996) with the distinction between diagnostic and interactive…

2000

Abstract

Recent accounting research has connected the coercive and enabling types of formalisation (C/E) (Adler and Borys, 1996) with the distinction between diagnostic and interactive controls (D/I) proposed by Simons (1995, 2000) to tackle research questions on complex control situations involving both the degree of employee autonomy and patterns of management attention. The diverse conceptual approaches used for connecting C/E and D/I have led to fragmentation in the literature and raise concerns about their conceptual clarity. In this paper, we assess the conceptual clarity of various forms of connection between C/E and D/I. Firstly, we conduct an in-depth content analysis of 59 recent papers, and inductively identify three points of conceptual ambiguity and divergence in the literature (namely, the perspective from which a phenomenon is studied; whether categories capture choices driven by design or by style-of-use; and the properties of control systems). We also observe that the literature proposes various forms of connection (i.e. coexistence, inclusion, and combination approaches). Secondly, we use the three detected points of ambiguity and divergence as assessment criteria, and evaluate the extent to which conceptual clarity is at risk under each form of connection. Based on this assessment, we provide guidelines to enhance the conceptual clarity of the connections between C/E and D/I, propose several research models, and indicate opportunities for future research in this area.

Details

Journal of Accounting Literature, vol. 43 no. 1
Type: Research Article
ISSN: 0737-4607

Keywords

Article
Publication date: 18 September 2007

G. Tessier, M. Bardoux, C. Filloy, C. Boué and D. Fournier

Heating is a major cause of failure in integrated circuits. The authors have designed thermoreflectance‐based systems operating at various wavelengths in order to obtain…

Abstract

Purpose

Heating is a major cause of failure in integrated circuits. The authors have designed thermoreflectance‐based systems operating at various wavelengths in order to obtain temperature images. This paper aims to explore the possibilities of each wavelength range and detail the charge coupled device (CCD)‐based thermal imaging tools dedicated to the high‐resolution inspection of integrated circuits.

Design/methodology/approach

Thermoreflectance is a non‐contact optical method using the local reflectivity variations induced by heating to infer temperature mappings, and can be conducted at virtually any wavelength, giving access to different types of information. In the visible, the technique is now well established. It can probe temperatures through several micrometers of transparent encapsulation layers, with sub‐μm spatial resolution and 100 mK thermal resolution.

Findings

In the ultraviolet range, dielectric encapsulation layers are opaque and thermoreflectance gives access to the surface temperature. In the near infrared, thermoreflectance is an interesting solution to examine chips turned upside down, since these wavelengths can penetrate through silicon substrates and give access to the temperature of the active layers themselves.

Research limitations/implications

The authors show that the illumination wavelength of thermoreflectance should be chosen with care depending on the region of the integrated circuit (surface, above, or below the substrate) to be investigated.

Practical implications

This set of versatile and sensitive tools makes thermoreflectance an interesting tool for the semiconductor industry, either during prototyping or as a characterization tool after fabrication.

Originality/value

The CCD‐based thermoreflectance approach adopted here allows fast, non‐contact, high‐resolution thermal imaging of integrated circuits.

Details

Sensor Review, vol. 27 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

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