Lead-free soldering for automotive glazing

A grace period given to the automotive industry by the European Union (EU) to phase out the use of lead-based soldering materials for automotive glazing is about to expire – with the consequences being felt globally. 

The move toward lead-free materials in electronics was given legal teeth when, on February 13, 2003, the use of lead-free materials became obligatory in the European Union (EU), with an implementation date of July 1, 2006. From that date on, no electronic products (except those with exemptions) may be made in or shipped to the EU if they contain lead.

The moves by the EU are part of a global trend. In 1970, the U.S. formed the Environmental Protection Agency (EPA). This is the first time in history that a nation had taken comprehensive stock of the quality of its surroundings. One of the EPA’s greatest achievements is banning lead (Pb) additives in gasoline — reducing the concentration of lead in the air by 94% from 1980 to 1999. In April 1993, the Lead Exposure Reduction Act (S. 729) and others were introduced in the U.S. banning lead for plumbing, housing, etc. However, lead in electronics products was exempted.

The EU is, however, continuing to expand the number of products which are required to be lead-free – the latest being automotive glazing. The regulatory constraints, as well as the constant performance improvements required of their suppliers by the OEMs are a permanent challenge for glass makers. One of the leaders in the field of developing lead-free sensors for automotive glazing to ensure additional vehicle occupant comfort and safety is Saint Gobain Sekurit, which is celebrating its 350th anniversary as a company in 2015.

Automotive Industries (AI) asked Dr Volkmar Offermann International Marketing Manager Saint-Gobain Sekurit, what prompted the company to develop its own internal solution for lead-free soldering. Offermann: The European Commission has introduced legislation that bans solders containing lead from automotive glazing. All new car models that are homologated from January 1st 2016 will have to use exclusively lead-free technologies for soldering connectors on glass. The legislation does not only apply to cars manufactured in Europe, but also to cars that are manufactured elsewhere and then exported to Europe. It is, therefore, a challenge to the worldwide automotive industry. Given Saint-Gobain’s R&D knowledge and expertise about glass and components and because of lack of solutions provided by the market, SGS decided to develop and propose its own solution. Our objective was to provide the best quality lead-free soldering.

AI: What were the challenges? Offermann: The EU requirement is a very big challenge, since leaded solutions have been used over several decades, and only a limited amount of time was available to develop equivalent lead-free solutions. Saint-Gobain Sekurit has, however, taken up the challenge and has been able to very rapidly develop a lead-free soldering solution which includes a variety of connectors that will address the needs of car manufacturers. The lead-free technology developed by Saint-Gobain Sekurit meets all OEM specifications, as well as specifications defined by VDA, Jama, USCAR, etc.

AI: What are the specifications for the SGS solution? Offermann: Because Saint-Gobain is constantly working on providing the best product quality and robustness, our leadfree soldering solution is mainly based on VDA specifications. The VDA specifications take into account demanding environmental conditions, such as hot southern Europe areas in summer, where one has to factor in the design of the car, screen inclination, and the thickness and color of the glass – all of which affect the heat load. The temperature load measured on backlights goes up to 130°C. That is why the product is tested at those temperatures. In the end, passing VDA specification assures the car manufacturer that the product provides the highest robustness even under high temperature loads. The Saint-Gobain soldering solution is able to fulfil the VDA specification at the high level of temperature mentioned when others fail below 100°C.The patented SaintGobain lead-free solution even exceeds the requirements, as it can be used not only for soldering on glass, but also for soldiering inside laminated glazing, a requirement that is currently still under discussion at European Union level.

AI: Is the design of your connectors flexible enough for customization? Offermann: Saint-Gobain has developed a portfolio of different types of connectors to make sure that there is a solution for all carmaker’s specifications. The design of the connectors is allows for customization, in order to give any carmaker the flexibility to choose the most appropriate geometry that fits its own requirements, including tempered, laminated, or inside laminated glass. An additional advantage of the Saint-Gobain solution is that it needs less surface area than other solutions, and is less expensive than the Indium-based produces.

AI: Is your solution fully validated and ready to apply? Offermann: Some OEMs have already tested the Saint-Gobain solution extensively, and the first products were introduced to the market in 2013. The majority of European, American and Japanese OEMs have chosen Saint-Gobain’s solution for their future cars to be launched before 2016. AI: What makes SGS lead-free soldering solution unique? Offermann: Saint-Gobain Sekurit is the first glassmaker to propose such a solution. It has been able to pass the most critical testing conditions to meet legal and OEM standards. This ensures the level of robustness required to avoid the separation of the components, and the malfunctioning of the heating network or breakage of the glass.

AI: Where are we going to see it first? Offermann: The new VOLVO XC90 is using SGS Leadfree. This model will be followed by the recently revealed Renault KADJAR.  Several more models from different OEMs will be launched over the next few months.

AI: What is next for SGS? Offermann: The prospects of autonomous cars make connectivity a real mega trend and challenge. Saint-Gobain Sekurit is positioned to meet the requirements of the marketplace, and to be a step ahead to make proposals for automotive glazing. Meeting the requirements of new generation of Head up Displays or touch controlled glazing are some examples. We also focus our R&D developments in CO2 savings with thinner glazing, new polymers and more thermal comfort through technology like reinforced infra-red windshields and low emissivity roofs (as seen in the recently launched SGS ComfortSky).    

AI: Finally, tell us about your birthday celebrations Offermann: This year, Saint-Gobain is celebrating its 350th anniversary. The company will mark this exceptional milestone by celebrating its history, but also having its sights firmly set on the future. The year 2015 will be packed full of events. The celebrations began on the 9th of January in Shanghai (China) and will end in October in Paris (France).