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Article
Publication date: 1 June 1997

C. Melton and H. Fuerhaupter

The use of lead in electronics assembly operations has come under scrutiny due to health and environmentalconcerns associated with lead exposure. Lead is one of the most useful…

443

Abstract

The use of lead in electronics assembly operations has come under scrutiny due to health and environmental concerns associated with lead exposure. Lead is one of the most useful metals in modern industry; however, lead has the dubious distinction of being one of the most toxic of metals. Increasingly restrictive government regulations on the use of lead are hastening the search for feasible alternatives to tin‐lead solder alloys. From an electronics assembly standpoint, there is a desire to replace lead bearing HASL (hot air solder levelling) coatings with a metallic, lead‐free alternative. To answer these needs, Motorola have developed a lead‐free, immersion plating technology for the surface finish of PCB printed circuit board bond pads. The Motorola development work has focused on the metallurgical system of tin‐bismuth, which is a simple eutectic system similar to that of tin‐lead, featuring a minimal number of phases and a wide operating window.

Details

Circuit World, vol. 23 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 8 February 2008

Sven Lamprecht, Günter Heinz, Neil Patton, Stephen Kenny and Patrick Brooks

The purpose of this paper is to show production process developments and innovations that resolve many of the issues faced with certain process steps for printed circuit board…

Abstract

Purpose

The purpose of this paper is to show production process developments and innovations that resolve many of the issues faced with certain process steps for printed circuit board (PCB) manufacturing following “green” practices.

Design/methodology/approach

Several key PCB manufacturing processes have been developed or studied with respect to new environmental legislations and practises.

Findings

The introduction of new legislations designed to protect the environment require changes to laminate materials, solders, and PCB manufacturing techniques. The effect of new laminate materials on the desmearing and metallising processes have been assessed and recommendations given. The effect of increased thermal stress on plated copper has been assessed. Developments in adhesion enhancement for black oxide alternatives have been made and are presented with their suitability for the newer green laminate materials. The development of a new laminate manufacturing technique to reduce environmental impact is introduced. The capabilities of different surface finishes in relation to new lead‐free soldering techniques is investigated and presented.

Research limitations/implications

This is a short paper covering several major PCB processing steps and covers experiences and development results.

Originality/value

The paper details how “green” PCB manufacturing affects some key processes, developments to improve results and environmentally friendlier innovations in laminate manufacturing techniques.

Details

Circuit World, vol. 34 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 April 1998

Anton Zoran Miric and Angela Grusd

In recent years, efforts to develop alternatives to lead‐based solders have increased dramatically. These efforts began as a response to potential legislation and regulations…

1043

Abstract

In recent years, efforts to develop alternatives to lead‐based solders have increased dramatically. These efforts began as a response to potential legislation and regulations restricting lead usage in the electronics industry. Lead is extremely toxic when inhaled or ingested. As researchers began to focus on Pb‐free solders, they recognized their value in high temperature applications (e.g. automotive manufacturing) where Sn/Pb solders do not meet the requirements. There are many factors to consider when developing lead‐free alloys: manufacturability, availability, reliability, cost and environmental safety. Of these, the most challenging and time consuming is the reliability of alternative solders. The lead‐free alloys available cannot be used as a drop‐in replacement for the SnPb or SnPbAg. The introduction of lead‐free solder alloys may mean having to use alternative component and PCB metallizations, PCB materials, solder fluxes, etc.

Details

Soldering & Surface Mount Technology, vol. 10 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

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