Why Laser Cutting Doesn’t Work
Thermal gap pads—silicone, urethane, or hybrids—don’t cooperate with lasers:
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Silicone-based pads: The laser chars the material, leaving burnt, brittle edges that flake.
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Urethane or silicone-free pads: Even without silicone, these pads melt or gum up under a beam.
The result is poor edge quality, adhesive contamination, and compromised thermal performance.
Knife Cutting: Possible but Not Practical
Oscillating knives, or CNC blades can cut thermal pads, but they introduce problems:
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Pads tend to drag, stretch, or distort under the knife.
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Fiberglass or film-reinforced pads resist penetration and require slower feeds.
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Toolpaths take longer, making knife cutting inefficient for production volumes.
Waterjet and Die-Cutting: The Reliable Approaches
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Waterjet cutting eliminates heat, producing smooth edges, but it’s slower and costlier per part.
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Conventional die-cutting—steel-rule or matched-metal—applies a clean shearing/crush-burst action, making it the fastest and most repeatable method.
This is why die-cutting remains the industry’s preferred solution.
Carriers and Liners: Shearing Resistance vs. Distortion
Thermal pads often include carriers and liners that affect how they behave during cutting:
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Fiberglass scrims: These don’t wear down dies but resist shearing—you need higher tonnage and tighter clearances to split them cleanly.
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Polyimide or polyester films: Add dimensional stability but demand precise die geometry to prevent incomplete cuts.
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Flexible diamond-embossed blue release liners: These create unique problems. Because they flex too much, they distort the crush-burst action of die-cutting. Instead of transferring the shearing force directly into the pad, the liner absorbs and shifts under pressure, reducing cut consistency and edge quality.
The challenge isn’t tool damage—it’s about controlling how force transfers through these layers during the shearing process.
Key Takeaway
For thermal gap pads:
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Laser cutting → charred, brittle, or gummy edges.
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Knife cutting → feasible, but slow and inconsistent.
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Waterjet cutting → clean, but costly at scale.
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Die-cutting → clean, fast, repeatable, and production-ready—though carriers and liners (especially fiberglass and flexible blue release liners) require careful process control.