Bosch Australia fixes its lead-free plating process

3 minute read

Rows of blue and silver diodes on a metal platform

Bosch Australia used the TrACEES platform to identify and solve a problem on its production pipeline for nickel-plated diode housings.

The outcome

Bosch Australia estimates savings of around $A795 000 for 2019 after it solved a problem on its production pipeline for nickel-plated diode housings using the Melbourne Trace Analysis for Chemical, Earth and Environmental Sciences (TrACEES) platform.

The need

Diodes are an important part of modern cars. They contain semiconductor chips that allow electricity to flow in only one direction – playing an essential role in powering lights, wipers, radios, and battery charging.

A nickel-plated housing protects diodes from corrosion. A single batch of a plating solution is used to coat millions of parts in a process called barrel plating. A stabiliser – often lead – is added to stop the plating solution from decomposing.

To reduce the use of hazardous chemicals, Bosch Australia introduced a lead-free plating solution for its entire diode portfolio in January 2019. During the development phase in 2018, the company discovered that the plating solution was unstable. This reduced its effectiveness for mass manufacturing.

Bosch’s Australia plant exports around 120 million diodes per year, about 20 per cent of the global market. It is the only site worldwide where the Bosch Group makes diodes. It was therefore critical that the company identify and solve the problem quickly to support its customers.

The solution

The TrACEES analysis found that the concentration of the new lead-free stabiliser varied between batches of the plating solution, causing the inconsistencies in the plating process. It turned out that the barrel plating process allowed the stabiliser to precipitate out of solution over time, therefore reducing its final concentration. This led to problems in the plating process, which reduced the intended lifetime of each batch of plating solution. The need to replace the solution more often caused significant downtime on the production line. With feedback from Bosch Australia, the chemical supplier was able to fix the problem.

The results of the TrACEES analysis helped Bosch Australia scale up use of the lead-free plating chemical solution to meet the demands of the barrel plating process. The company eliminated the inconsistencies and increased productivity by as much as 52 per cent using almost 40 per cent less plating solution.

The TrACEES team analysed samples and delivered results with a 1–3 day turnaround. From initial approach to final results, the project took less than two months to identify the root cause of the problem.

The platform

The Trace Analysis for Chemical, Earth and Environmental Sciences (TrACEES) platform is a suite of equipment operated by staff with analytical and technical expertise in the chemical, materials, environmental and life sciences. Platform staff provide bespoke solutions to industrial and scientific problems. They can call on University of Melbourne researchers for specific expertise.

The techniques used in this project include:

  • atomic absorption spectrophotometry (AAS) – determines the concentration of a target element by measuring how much light it absorbs. AAS can detect levels as low as a few parts per billion – the equivalent of a few micrograms of material in a kilogram of sample.
  • inductively coupled plasma optical emission spectroscopy (ICP-OES) – uses plasma (generated by ionising argon gas) to excite electrons within a sample. The electrons then emit light at wavelengths characteristic of particular elements. The intensity of the emission indicates the concentration of that element in the sample. Unlike AAS, ICP-OES can measure more than one element in a sample. The sensitivity of ICP-OES is similar to that of AAS, but ICP-OES is more expensive and requires more technical skill to perform.

Contact us

If you have a problem that could be solved by the TrACEES team, contact:

Dr Alex Duan, Platform Manager

duanx@unimelb.edu.au

Phone: +61 3 8344 6485

Partner

Robert Bosch Australia Pty Ltd, a wholly owned subsidiary of the global Bosch Group.

Image: Bosch Australia

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