Ultrashort Pulse Lasers for PCB and Copper Structuring
Ultrashort pulse laser processing is a candidate for fine copper patterning, electrical isolation and selected PCB machining tasks. For an electronics developer, the key question is practical: can the required copper be removed while preserving the material underneath, at a useful cost per board?
Start with the layer stack, not just the laser power
A copper foil on a polymer film presents a different processing problem from copper on a glass-reinforced laminate or ceramic. Copper thickness, surface finish, adhesive layers and the dielectric all belong in the enquiry. Include the actual material grade and a cross-section if available. A trial on bare metal alone cannot establish the quality of a multilayer PCB process.
Ultrashort pulses can support precise material removal with limited surrounding thermal effects. They do not make a process automatically heat-free. Pulse overlap, repeated passes and the time between successive scans remain relevant. Fraunhofer ILT describes ultrashort pulse processing for selective thin-film removal, drilling and cutting.
Three different tasks need different acceptance criteria
- Copper isolation: specify the minimum gap, permitted substrate damage and electrical isolation requirement. A visually clear groove is not sufficient evidence of electrical performance.
- Area removal: state how much copper must be cleared and whether residue or redeposited particles are acceptable. Large cleared areas can dominate the processing time.
- Microvias: define entry and exit diameters, depth, taper and the layer where the hole must stop. Also explain subsequent cleaning and metallisation steps.
What a useful PCB processing trial should measure
Send a representative coupon containing straight tracks, corners, small gaps and a cleared area. Agree on microscopy, dimensional measurements and electrical checks before processing. Where substrate integrity matters, include cross-section inspection. Record the material batch and surface preparation so that a successful result can be repeated.
Ask for the complete cycle time: loading, alignment, scanning, repeat passes, cleaning and inspection. The scanner's travel speed alone does not describe board throughput. Compare good boards per hour and accepted feature quality against the existing manufacturing route.
Does a green femtosecond laser guarantee better results?
No wavelength or pulse-duration label replaces a material trial. Define the feature and acceptance criteria first, then evaluate a suitable combination of wavelength, pulse energy, focus and scan strategy. Femtosecond and picosecond sources both belong to the ultrashort pulse family, but their suitability must be checked for the particular stack.
Discuss your application with DIY-Optics
DIY-Optics GmbH develops the PulseBrick ultrashort pulse laser platform in Switzerland and provides optical and laser engineering. For a feasibility discussion, sample-processing enquiry or potential jobshop project, send us your material-processing requirements. We will confirm the available process route, scope and timing before a trial is agreed.
Preparing an enquiry? Use our laser processing trial checklist, or explore laser and optical engineering services.