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Views: 0 Author: Site Editor Publish Time: 2025-11-08 Origin: Site
A 375nm/405nm UV fiber-coupled laser is used for LDI (Laser Direct Imaging) by precisely transferring a digital image directly onto a photosensitive material, such as a PCB. The fiber coupling directs the UV light to a scanner or printhead, where it is rapidly focused and moved across the substrate, creating patterns without the need for physical masks. The specific wavelength (375nm or 405nm) is chosen for its effective absorption by the imaging materials used in LDI applications.
Direct imaging: The laser replaces traditional photolithography by directly imaging the design onto the surface, which reduces processing steps and time.
High resolution: The use of single-mode fiber coupled lasers allows for high-quality, fine-pattern generation, which is crucial for modern, high-density electronics.
Precise control: The fiber can deliver the beam to the printing head, enabling precise control over the laser's movement and focus, which is essential for accurate pattern creation.
Customizable application: The fiber-coupled design is compact and easily integrated into existing LDI systems, allowing for flexible and scalable solutions.
Laser Direct Imaging, commonly referred to as LDI, is a cutting-edge technique used in PCB manufacturing to create highly precise circuit patterns. Unlike traditional methods that rely on photomasks or film negatives to transfer designs onto a board, LDI uses an ultraviolet (UV) laser to directly "write" the circuit pattern onto a photosensitive layer on the PCB. This process is controlled by sophisticated software, ensuring accuracy down to the micrometer level.
The elimination of physical masks not only reduces production time but also minimizes errors caused by misalignment or mask wear. LDI is particularly valuable for high-density interconnect (HDI) boards, flexible circuits, and advanced designs required for 5G technology and IoT devices. By directly imaging the design, manufacturers can achieve finer lines and spaces—often below 50 micrometers—making it ideal for miniaturized electronics.
The LDI process is both fascinating and highly efficient. Here's a step-by-step breakdown of how it works:
Design Data Input: The PCB design is uploaded into the LDI system's software. This digital file contains all the details of the circuit pattern, including traces, pads, and vias.
Substrate Preparation: The PCB substrate, typically coated with a photosensitive resist material (photoresist), is loaded into the LDI equipment.
Laser Exposure: A UV laser beam, guided by the digital design data, scans across the photoresist layer. The laser exposes specific areas of the resist, hardening or softening it depending on whether it's a positive or negative photoresist.
Development: After exposure, the board goes through a chemical development process to remove the unexposed (or exposed, depending on the resist type) areas of the photoresist, revealing the circuit pattern.
Etching or Plating: The exposed copper areas are either etched away or plated, depending on the manufacturing step, to form the final circuit traces.
This process is incredibly precise, with laser resolutions often reaching 25 micrometers or less. It also allows for real-time adjustments to the design without the need to create new masks, saving both time and cost in production.
A UV laser diode (at 375nm or 405nm) is connected to an optical fiber.
The fiber transmits the laser light to the LDI system's printhead or scanner.
The light is then precisely controlled by a scanning system, which directs the laser beam across the substrate.
The beam exposes the photosensitive material, creating the desired pattern.
The laser's wavelength is selected for optimal absorption by the photosensitive layer on the PCB or other substrate.
Beyond LDI, these lasers are used in:
PCB plate making
Fluorescence excitation
Material processing
Biochemical research
3D printing
BU-LASER provides Semiconductor diode lasers with violet, cyan, blue, green, red and infrared color (375nm- 1064nm, 1mW-500W output power, different beam mode, and dimensions) to better meet customers’ needs of different applications. We also offer professional OEM &ODM service! To know more, please get in touch with us at song@bu-laser.com.
