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Article
Publication date: 1 December 1999

42

Abstract

Details

Circuit World, vol. 25 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1991

H.K. Straschil, I. Kadija, J. Maisano and J.A. Abys

Electroplating of palladium‐nickel alloy is becoming widely used, mainly for interconnection applications in the electronics industry and for decorative purposes. Enhanced…

Abstract

Electroplating of palladium‐nickel alloy is becoming widely used, mainly for interconnection applications in the electronics industry and for decorative purposes. Enhanced hardness and brightness combined with superior wear properties compared with hard gold deposits make this alloy desirable in many applications. Like pure palladium, palladium‐nickel is frequently covered with a thin layer of hard gold to improve contact reliability; this results in a much less expensive and longer‐lasting contact material than hard gold on its own. In response to the growing demand, the authors have developed a palladium‐nickel alloy electroplating process that can plate alloys of varying composition (10–50 w % Ni) at current densities ranging from <5 mA/cm to >500 mA/cm. This process produces specular, hard and ductile deposits up to a thickness of ‐25 ?m. The new palladium‐nickel alloy electroplating process is described with regard to its chemistry, operating conditions, bath maintenance and regeneration, diagnostic measures, and properties of the electrodeposits.

Details

Circuit World, vol. 17 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 September 1999

Chonglun Fan, Joseph A. Abys and Alan Blair

Palladium surface finishes are utilized on leadframes, printed wiring boards and automobile sensors. Their superior functional performance and the considerable…

Abstract

Palladium surface finishes are utilized on leadframes, printed wiring boards and automobile sensors. Their superior functional performance and the considerable environmental impact of plating lead‐free finishes for packaging processes have been increasingly recognized by the electronic industry. Wire bondable and solderable palladium finishes meet military and industrial standards at no extra cost in the overall assembly processes when compared to traditional packaging techniques. In addition to the development of palladium plating chemistries and technologies, the functional properties of the surface finishes including their wire bonding performance have also been investigated at Bell Laboratories. In this study, gold and aluminum wire bonding to palladium finishes was tested and the wire bond pull force and break position were examined in order to optimize the bonding processes. The results of the study are reported in this paper.

Details

Circuit World, vol. 25 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 March 1999

Yun Zhang and Joseph A. Abys

A novel tin electrodeposition chemistry and process has been developed at Bell Laboratories, Lucent Technologies, New Jersey, USA. This process produces smooth, satin…

1454

Abstract

A novel tin electrodeposition chemistry and process has been developed at Bell Laboratories, Lucent Technologies, New Jersey, USA. This process produces smooth, satin bright tin deposits which have stable, large grain structures. The deposits contain very low organic content and, as a consequence, exhibit excellent ductility, solderability and reflowability. The chemistry is capable of operating at elevated temperatures over a wide range of current densities, and is, thus, applicable to rack, barrel and reel‐to‐reel operations. All chemical components, including breakdown products are fully analyzable with conventional analytical methods. Extensive bath life studies show that the deposit appearance and material properties, including grain structures, are stable in relation to the age of the electroplating chemistry. In addition, the grain refiners used are highly stable, and have few breakdown products as the chemistry ages. All these features imply a robust process which has been confirmed in various manufacturing environments. This tin electroplating process has been utilized in plating coatings for connectors, solder bumps, PWBs and components for semiconductor applications.

Details

Circuit World, vol. 25 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 16 January 2020

Ashutosh Sharma and Byungmin Ahn

The purpose of this paper is to investigate the influence of pulse plating current density on the morphology and solderability of Pb-free Sn-Cu solder coatings prepared…

Abstract

Purpose

The purpose of this paper is to investigate the influence of pulse plating current density on the morphology and solderability of Pb-free Sn-Cu solder coatings prepared from alkaline stannate baths.

Design/methodology/approach

Sn-Cu solder coatings were produced from a plating solution containing sodium stannate, copper stannate, sodium hydroxide and sorbitol additive on copper substrates. The pulse plating experiments were conducted in galvanostatic mode. The plating current density was varied from 5 to 25 mA/cm2, and the morphology of the coatings was studied. The solderability of the coatings was assessed by spread ratio measurement after reflowing the solder coatings at 250°C.

Findings

The composition control of eutectic solders is always a challenge in plating. The findings show that Sn-Cu coatings prepared by pulse plating are composed of tetragonal ß-Sn structure and Cu6Sn5 compounds irrespective of bath composition and conditions. The final coatings were very dense and smooth with nodular morphology. It was shown that a eutectic composition can be achieved if we apply a current density of ∼15-20 mA/cm2. The solderability studies suggest that solder coatings plated at and beyond 15 mA/cm2 are more suitable for solder finish applications.

Originality/value

The work presents key issues in pulse electroplating of Sn-Cu solder coatings from an alkaline bath. Possible strategies to control the eutectic Sn-Cu composition by plating process are recommended.

Details

Soldering & Surface Mount Technology, vol. 32 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 5 April 2013

Yingxin Goh, A.S.M.A. Haseeb and Mohd Faizul Mohd Sabri

The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve…

1241

Abstract

Purpose

The purpose of this paper is to enhance the understanding on the electrodeposition of various lead (Pb)‐free solder alloys, so that new studies can be carried out to solve processing issues.

Design/methodology/approach

The paper reviews the available reports on the electrodeposition of tin (Sn)‐based solder systems and identifies the challenges in this area.

Findings

Compositional control remains a major challenge in this area, where the achievement of desired composition for binary and ternary alloys is subjected to uncertainties. The use of chelating agents in the bath and optimization of parameters can assist the achievement of near‐desired alloy composition. Acidic plating baths are preferred due to their compatibility with photoresists but oxidation of stannous ions causes poor bath stability. Antioxidants, reducing agents and low oxygen overpotential anodes can suppress the oxidation rate and increase the lifespan of plating baths. Apart from chelating agents and antioxidants, various categories of additives can be added to improve quality of deposits. Surfactants, grain refiners and brighteners are routinely used to obtain smooth, fine‐grained and bright deposits with good thermo‐mechanical properties.

Originality/value

The paper provides information on the key issues in electrodeposition of Pb‐free solder alloys. Possible measures to alleviate the issues are suggested so that the electrodeposition technique can be established for mass production of a wider range of solder alloys.

Details

Soldering & Surface Mount Technology, vol. 25 no. 2
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 1 March 1987

Appointments Leitron GmbH In strengthening its Sales Division, Leitron GmbH of Schwäbisch‐Gmünd has appointed Mr Heinz Schunk to be responsible for General Management of…

Abstract

Appointments Leitron GmbH In strengthening its Sales Division, Leitron GmbH of Schwäbisch‐Gmünd has appointed Mr Heinz Schunk to be responsible for General Management of Sales and Marketing.

Details

Circuit World, vol. 13 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 December 2005

Sabine Schroeder

To provide information about latest product developments to address and take away the fear of whisker formation on pure immersion tin surface finishes on PCBs.

Abstract

Purpose

To provide information about latest product developments to address and take away the fear of whisker formation on pure immersion tin surface finishes on PCBs.

Design/methodology/approach

This paper summarises the latest findings on whisker formation of pure tin surface finishes and describes an effective methodology for whisker suppression in combination with other benefits for the use of this new immersion tin generation.

Findings

Whisker formation is a typical feature of pure tin when coated, e.g. on copper and is a threat to the PCB industry, because of the risks of shortcuts involved. The main driving force for whiskers is an accumulation of internal stress created by diffusion at the boundary of copper and tin. A nano layer deposited from an organic metal‐based pre‐dip significantly reduces the diffusion by creating a unique sandwich layer with smooth concentration gradients. A drastic reduction of diffusion and stress was found, eliminating the driving force for whisker formation and prolonging the layer's shelf life and temperature stability at the same time.

Practical implications

Whenever whisker formation on immersion tin is regarded as a potential risk, e.g. by OEMs, a whisker‐reduced process is available and should be chosen to meet the market's specifications.

Originality/value

This paper takes the edge off the whisker threat discussions, leading to a hesitant implementation of immersion tin surface finish technology for PCBs, which disregard its excellent features with respect to future lead‐free soldering. Whisker‐reduced immersion tin is a viable and preferable alternative solderable surface finish for the lead‐free era.

Details

Circuit World, vol. 31 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 December 1997

Klas Soderquist, J.J. Chanaron and Jaideep Motwani

Presents the results of a survey of how innovation is managed by French small and medium‐sized enterprises. Focuses on drivers for change, actions to improve short‐ and…

2681

Abstract

Presents the results of a survey of how innovation is managed by French small and medium‐sized enterprises. Focuses on drivers for change, actions to improve short‐ and long‐ term profitability, sources of innovation, and the relationship between different managerial orientations in the companies and the dynamics of innovation. The results show that a strong customer orientation ‐ together with a true partnership with main customers ‐ and continuous improvement of the company’s internal processes are key factors both for successful R&D and improvement of performance.

Details

Benchmarking for Quality Management & Technology, vol. 4 no. 4
Type: Research Article
ISSN: 1351-3036

Keywords

Article
Publication date: 6 February 2017

Balázs Illés, Barbara Horváth, Attila Géczy, Olivér Krammer and Karel Dušek

The aim of this paper is to present a review of the tin whisker growth phenomena. The study focuses mainly on whisker growth in a corrosive climate when the main inducing…

Abstract

Purpose

The aim of this paper is to present a review of the tin whisker growth phenomena. The study focuses mainly on whisker growth in a corrosive climate when the main inducing factor of the whisker growth is oxidation. The tin whisker phenomenon is still a big challenge in lead-free reflow soldering technology. Modern lead-free alloys and surface finishes with high tin content are considered to be possible sources of whisker development, also the evolution of electronic devices towards further complexity and miniaturization points to an escalation of the reliability risks.

Design/methodology/approach

The present work was based on a worldwide literature review of the substantial previous works in the past decade, as well as on the results and experience of the authors in this field.

Findings

The effect of corrosion on tin whisker growth has been under-represented in reports of mainstream research; however, in the past five years, significant results were obtained in the field which raised the corrosion phenomena from being a side effect category into one of the main inducing factors. This paper summarizes the most important findings of this field.

Practical implications

This literature review provides engineers and researchers with a better understanding of the role of corrosion in tin whisker growth and the current challenges in tin whisker mitigation.

Originality/value

The unique challenges and future research directions about the tin whisker phenomenon were shown to highlight rarely discussed risks and problems in lead-free soldering reliability.

Details

Soldering & Surface Mount Technology, vol. 29 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

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