Customer Story


Meeting the Challenges of High-Quality, High Value-Added Machining, the Source of Sungsan’s Unique Integrity and Standards

Customer Story_Sungsan Corp

Challenge of Sungsan Corp.! Opportunities Brought by High-Precision Mold Processing and Grinding Technology

Sungsan Corp., a supplier of Samsung Display Co., Ltd., specializes in the production of display mask frames. Established in 1995 as Sungsan Engineering, the company initially specialized in the machining of semiconductor equipment and LCD screen cleaning equipment parts. Fifteen years ago, Sungsan fixed Samsung’s problem with its mask frame machining task, leading to a special relationship that has endured to this day. Korea was then about to apply OLEDs for a folder mobile phone for the first time. However, it was difficult to find a mask frame manufacturer that could meet the demand for an extremely high level of flatness and precision. The leading display manufacturer in the country sought a machining company that could meet its demand, leading to its encounter with Sungsan, which was already equipped with highprecision mold processing and grinding technology.

Sungsan met the company’s requirement by securing an OLED screen mask frame with a flatness of 0.15mm. Kang Seung-bo, the CEO of Sungsan, said, “We resolved the company’s machining difficulties a number of times, presenting them with satisfactory machining results. By and large the company’s trust in us grew, and large orders followed.” He recalled that he had never imagined that his business would grow so big, though. “The larger the frame, the bigger the machining area becomes, making it harder to meet the requirement for flatness. So more precise machining technology is required,” said Kang Seungbo.

“Most notably, mask frames go into vacuum chambers. Consideration must be given to their weight and material deformation risks.” Currently, Sungsan supplies the company with not only smallsized mask frames but mid- and large-sized mask frames with a flatness of 0.025mm and 0.03mm, respectively, earning a great deal of trust from the firm.

The Solution is Doosan M Challenge of Sungsan Corp.! achine Tools’ VM950 Vertical Machining Center!
Increasing Machine Tool Investment to Meet Demand for Mask Frame Surfaces

In line with an increase in mask frame orders, Sungsan purchased twelve VM950s, Doosan Machine Tools’ vertical machining center, and a BM 2035M model optimized for the production of large frames.

Out of a few domestic mask frame producers, Sungsan boasts the most prominent technological prowess and the highest production yield. “We start getting involved in the development stage. We make standards for production lines, and mass produce to meet our customer’s diverse needs. As such, we have been able to stabilize both our product and our productivity,” said CEO Kang Seung-bo. “At the beginning of mass production our production yield stood at 75%, but we have constantly upgraded our production processes, and the rate is now 95%.” Such a high production yield can be realized only when a company is equipped with proper cutting technologies, machine tools and production infrastructure. It is impossible to achieve either without close communication, technological consensus and mutual trust with the customer.

Most notably, CEO Kang standardized not just the processes but also the machining technologies and cutting tools to minimize the company’s defect rate. He stressed that the role of ‘machine tools’ is critical in stabilizing the production of goods. He says that his company used Doosan Machine Tools’ NC lathes and Nos. 4, 5 and 6.5 to produce the parts required for semiconductor equipment and LCD cleaning equipment. To produce mask frames, he says that he has only ever used the products of Doosan Machine Tools. “Invar 36 is low in hardness, but it contains 36% nickel. Thus, it is not easy to cut. Proper tools must be used,” said CEO Kang. “Doosan machinery meets all the requirements. It outperforms the competition in cutting speed and productivity, in particular, when it comes to mold machining,” stressing his satisfaction with his choice of Doosan Machine Tools.

Sungsan’s Unique Criteria: ‘Optimization, Process Simplification, Specialization’

“Reducing the machining time does not translate to a reduction of cutting time,” said CEO Kang. “It takes 72 hours to machine a large-sized mask frame. Saving a few minutes in cutting does not affect productivity that much.” He says that it is more effective to reduce the lead time by reducing the workpiece setting and operation time, adding, “It is important to simplify the processes and upgrade the programs so that we can optimize the processes that our workers have to adapt to. It is also critical to help our workers to continue enhancing their know-how and expertise in what they are doing.” While referring to his company’s unique customized production and anufacturing system, he emphasized the importance of sourcing machine tools from a single supplier to reduce operational confusion among workers and help them minimize their prep time.

CEO Kang said that as the display technology has evolved from LCD to PDP to OLED, the mask frame technology has also developed, with the demand for parts continuing to increase. “We are planning to purchase machine tools that are excellent in heavy cutting," he added. “We hear that Doosan Machine Tools has already tested our products in its lab and upgraded its machinery according to the test results,” praising the efforts of Doosan Machine Tools to respond promptly to customer needs.