TOKK LDI Exposure Machine Solution
In the field of PCB manufacturing, every process innovation drives the electronics industry toward higher density and finer line widths. LDI (Laser Direct Imaging) technology completely abandons traditional film photomasks, using high‑energy ultraviolet lasers to directly pattern the substrate surface, achieving a leap from "mask‑based" to "mask‑less" direct writing. Much like an ultra‑precision industrial projector, it converts PCB design data (e.g., Gerber files) directly into laser beams that scan and expose the photoresist‑coated substrate at high speed, forming the circuit "latent image" and greatly improving the precision and flexibility of circuit fabrication.
However, the imaging quality and production efficiency of LDI equipment depend critically on the accuracy, speed, and stability of the motion control system. TOKK has developed a core motion platform for LDI exposure machines that redefines industry imaging standards with an innovative dual‑stage mechanical structure, multi‑axis synchronized motion control, and micron‑level positioning precision.
Traditional exposure processes rely on film photomasks, which involve cumbersome procedures, high costs, and limited precision. LDI technology follows a four‑step workflow – "precise data input → high‑energy laser generation → spatial light modulation → precision scanning exposure" – to directly translate digital designs into circuit patterns. Its core advantages include:
- Precision breakthrough: Eliminates physical constraints such as film expansion/shrinkage and alignment errors, meeting the fine‑line requirements of high‑density interconnect (HDI) boards.
- Flexible production: No need to fabricate physical masks; product types can be switched quickly, making it ideal for diverse, small‑batch production.
- Yield improvement: Digital direct writing avoids pattern distortion and pad misalignment common in traditional processes.
The core motion platform provided by TOKK for LDI exposure machines features an innovative mechanical design and integrates ultra‑high‑precision multi‑axis synchronized motion control, enabling dual‑stage alternating operation.
1. Dual‑stage asynchronous independent control: The core design for doubled productivity
The platform adopts a Y1/Y2 dual‑exposure‑stage configuration, allowing alternating operation – "one stage exposing, the other loading/unloading". Each stage is driven by an independent linear motor system, enabling fast, interference‑free motion. This parallel operation eliminates the waiting time for loading/unloading found in single‑stage designs, achieving zero‑gap process衔接 and boosting overall equipment effectiveness (UPH) by 30%‑50%.
2. Top‑tier hardware configuration and hybrid drive solution
The platform is equipped with an ACS motion controller and a hybrid drive combining ACS linear motors with Panasonic servos. The X/Y/K core axes use water‑cooled linear motors to eliminate transmission errors and ensure high‑speed, high‑precision scanning; the Z‑axis uses a dedicated servo screw structure for precise focusing, with a fail‑safe brake to protect both equipment and workpiece. Linear motors deliver high speed, high acceleration, and low velocity ripple, while the screw servo provides low‑speed precision lifting and emergency braking.
3. Industry‑leading motion accuracy
High precision is the lifeline for PCB line quality and yield. The TOKK motion platform achieves top‑tier performance in positioning, repeatability, and feedback resolution:
- Positioning accuracy: Over the full travel, the compensated X/Y/K axes achieve a combined positioning accuracy of ±2 μm, fundamentally eliminating systemic motion errors.
- Repeatability: The X/K axes deliver a repeatability of ±1 μm, ensuring consistent pattern reproduction across high‑volume production.
- Feedback resolution: Equipped with 0.1 μm ultra‑high‑resolution linear encoders, providing the most precise data for real‑time servo correction.
4. High‑speed response and efficient tact time
The Y‑axis (exposure stage) reaches a maximum speed of 1.5 m/s, completing high‑speed positioning within milliseconds.
The K‑axis (camera axis) covers 800 mm in just 1.2 seconds, drastically shortening the image acquisition and alignment cycle.
5. PSO hardware‑synchronized laser triggering
In high‑speed LDI scanning, any delay in laser triggering can cause pattern misalignment. The TOKK platform uses a dedicated DB9 differential sync cable that routes the encoder A/B/Z signals directly to the hardware trigger input, bypassing software processing for zero‑latency signal transmission. This technology completely eliminates scan misalignment caused by software latency, representing a critical breakthrough for ensuring dynamic imaging quality and pattern consistency.
6. Tiered safety hardwiring and clean‑room compatibility
Critical safety signals – such as emergency stop and encoder fault – are implemented with independent hardwired connections, fully independent of the motion bus communication. In the event of a bus failure, drive enable can be cut directly to ensure personnel and equipment safety. Additionally, high‑flexibility shielded drag‑chain cables and a unified grounding design effectively suppress static and electromagnetic interference, perfectly suiting Class 100,000 cleanroom environments.
LDI exposure machines equipped with the TOKK motion platform deliver significant real‑world benefits:
- Yield assurance: ±2 μm positioning accuracy and ±1 μm repeatability eliminate error accumulation from the source, ensuring precise exposure placement – perfectly suited for Fine Line and HDI boards, markedly improving final yield.
- Productivity breakthrough: Dual‑stage parallel operation enables simultaneous exposure and loading/unloading; combined with a 1.5 m/s stage speed, overall equipment effectiveness (UPH) increases by 30%‑50%.
- Reliability: The tiered safety hardwiring and clean‑room design guarantee safe, dependable operation during continuous long‑term production.
From "film" to "digital", LDI technology is redrawing the boundaries of precision and efficiency in PCB manufacturing. With dual‑stage asynchronous control, micron‑level positioning, PSO hardware‑synchronized triggering, and a hybrid drive architecture, TOKK delivers a complete, efficient, and stable motion control solution for LDI exposure machines. Moving forward, TOKK will continue to deepen its expertise in precision motion control, empowering smarter PCB manufacturing to reach new heights.
TOKK Robotics (Suzhou) Co., Ltd. is a wholly‑owned subsidiary of Lingchen Group. The group also operates two other subsidiaries: Suzhou Xunya Automation Technology Co., Ltd. and TOKK Robotics (Suzhou) Co., Ltd. (TOKK), focusing on robotics sales and the R&D, production, and sales of linear motion products respectively.
TOKK specializes in the R&D, production, and sales of high‑precision granite stages, linear motor modules, linear transmission modules, electric cylinders, KK modules, and servo presses. Our products serve major industries including 3C, lithium battery, photovoltaic, display panels, and semiconductors, with wide applications in dispensing, material handling, scanning, and positioning – meeting diverse customer needs.
