LG Production Engineering Research Institute (LG PRI) has supplied its high-resolution Laser Direct Imaging (LDI) system, which eliminates the need for photomasks, to LG Innotek and an overseas printed circuit board (PCB) manufacturer, according to industry sources on July 27. Initial shipment volumes were limited as part of the product's first commercial deployment. The equipment is estimated to be priced at around KRW 3 billion per unit.
An LG PRI official said, "The LDI system has only recently entered commercial production," adding, "We have already sold the equipment to LG Innotek and other customers, while also conducting new sales activities and joint development projects with additional prospective customers."
Lithography is the process used to transfer circuit patterns during semiconductor manufacturing. It is employed in both front-end and back-end production, with LG PRI's system targeting advanced packaging applications in semiconductor back-end manufacturing. The equipment is used to create circuit and bump patterns on PCBs and interposers required for advanced packaging. The LDI system utilizes ultraviolet (UV) laser beams generated by a built-in high-power laser diode module, operating at an H-line wavelength of 405 nanometers.
The laser beam is directed to a Digital Micromirror Device (DMD), which consists of millions of microscopic mirrors arranged in a grid pattern. Each mirror operates independently and can tilt in response to computer-generated signals. By precisely controlling these mirrors, the system can produce fine circuit patterns ranging from 1.5 micrometers (µm) to 3.0 µm. Compared with conventional lithography methods, the technology reduces production costs and lead times by eliminating the need for photomasks.
Conventional stepper lithography systems require photomasks to be designed and manufactured before substrate production begins. A photomask is a plate containing fine circuit patterns used in semiconductor and substrate manufacturing. Different areas of the mask transmit light differently, allowing circuit patterns to be transferred onto the substrate during exposure. Because photomasks are expensive and must be newly fabricated whenever circuit designs change, they increase both cost and production time.
Stepper-based systems also face limitations in processing large-area substrates. Since they project light through a fixed photomask, they are vulnerable to alignment errors and pattern distortion caused by substrate warpage or bending. LG PRI's LDI system incorporates Real-Time Active Compensation (RTAC) technology to measure and correct distortion in real time, enabling high manufacturing yields for substrates measuring up to 600 mm by 600 mm.
LDI technology itself has been used for more than a decade in display manufacturing and conventional PCB production. However, rising demand for high-density AI memory such as High Bandwidth Memory (HBM) and large-area substrates has driven the development of a new generation of high-resolution LDI lithography systems. The equipment can be used to form Redistribution Layers (RDLs) on a variety of materials, including conventional PCBs, wafers and glass substrates.
LG PRI expects the system to play a key role in next-generation semiconductor packaging technologies such as Fan-Out Chip-on-Substrate (FoCoS) and Chip-on-Panel-on-Substrate (CoPoS). Building on initial deliveries to LG Innotek and other customers, the institute plans to expand its customer base to substrate manufacturers and outsourced semiconductor assembly and test (OSAT) providers worldwide, with the goal of increasing its market share.
