Fibre optic technology first gained widespread public awareness in the late 1990s when the world began to witness massive hikes in demand for communications bandwidth. This was mainly due to increased use of the Internet, and the commercialisation of various bandwidth-intensive consumer services, such as video on demand.

In 2014, the growth of this technology shows no signs of abating, with demand being driven by Internet video traffic, requests from the financial sector for ever-faster trading connections, and cell phone use which, by design, has to be linked into landline networks.

Stroke of luck

This is all good news for Year Round Technology Corp, a die-casting business based in the Wugu district of New Taipei City, Taiwan.

“We went into the fibre optic market because someone found us by chance,” admits the company’s sales manager, Jean Kuo. “Our customer began growing very quickly, and before we knew it, we were doing more and more work for them. We were very lucky to start in the fibre optic sector from the very beginning. As a result, we have a good understanding of our customer’s needs and expectations.”

The customer in question is a US-based company that has grown from humble beginnings to become the world’s largest supplier of optical communication components and sub-systems, employing around 12,000 people worldwide. The company’s products enable high-speed voice, video, and data communications for networking, storage, wireless, and cable TV applications.

With steady demand, Year Round opened a second manufacturing facility in 2008, a move that has since helped triple output. Today, fibre optic contracts account for around 70 percent of the company’s business.

Housing Requirements

One of the main fibre optic components manufactured by the company is the housing — the case for the module that generates the light. These modules, which are approximately the size of a human hand, are used in large systems for data communications/fibre optic servers. Ultimate end users include global business giants such as Cisco and Microsoft.

“The housing needs to be dimensionally accurate to within 25 µm, largely because of the fibre transmission,” says Ms Kuo. “If there are any deviations, it will impact performance. The housings also need to present an aesthetically pleasing exterior finish.”

Although the company has specialised in zinc die-castings since it was formed in 1980, around five years ago, the fibre optic industry began to shift towards aluminium die-castings, as these provide less weight and better thermal dynamics. However, the drawback with aluminium is that it requires more post-cast machining.

In-House Production

The manufacturer began aluminium die-casting in 2009 and initially outsourced the second-operation machining. However, the company soon confronted one of the biggest problems of outsourcing: quality control.

“We discovered that the yield — the number of castings returning from successful machining — was not very good,” says Ms Kuo. “Our subcontractor was only finding an out-of-tolerance dimension after machining had been completed. When machining die-castings, dimensions need to be checked during process, almost step-by-step. The design and accuracy of the fixture is also influential in achieving a successful part.”

Around two years ago, the company decided that outsourcing was not proving successful, and instead opted to purchase its own machine tools and started machining in-house. They eventually invested in four Haas VF-2SS Super Speed vertical machining centres and two DT-1 Dril/Tap Centres.

Better Yields

Three of the four vertical machining centres are used for performing second-operation machining of aluminium die-cast housings, with typical cycle times of around 40 minutes. The parts are loaded on a rotary fixture, machining two at once. Three sides are machined in a single clamping, before the housing is flipped for further operations.

One of the four-axis VF-2SS machines is also used to produce copper electrodes for the company’s EDM machines, which are used to manufacture the die-cast tooling. The electrodes, often with very thin features, are critical, as the tooling needs to be of high quality to produce upwards of 100,000 die-castings a week.

The other VF-2SS is a five-axis version that, although used for second-operation machining, is also deployed for prototype work. Prototypes are often made in batches of around 100, and allow the customer to ascertain if the design is good before the mould is produced.

The DT-1 machines are also used for a certain amount of prototyping, along with second-operation machining. Regardless of the machine deployed, regular dimension checking takes place throughout the machining process.

The upshot is a far better yield of castings through the machining stage, which allows Year Round to better control its costs. This fact is appreciated by the customer. Aside from cost and quality, the Taiwanese contract manufacturer also managed to offer turnaround performance of approximately 30 days (from new mould to first-article die-casting). They added that most of these first article items can then be taken directly into production.

“A lot of customers don’t require a prototype anymore; they order the first batch from the beginning, when we run the first cycle,” says Ms Kuo. “To achieve this, we must focus on quality. Although we are always threatened by cost-competition, the real value is being able to provide a mould that can produce hundreds of thousands of die-castings without any problems.”