INTERLITH - Step Collapse

What is Step Collapse?

Turn your UV line into a self contained assembly line. Step Collapse is a method that lets you pattern buried metal and lock components in place in one chemistry on glass or ceramic panels.

 

You replace copper + etch + plating and solder reflow with: coat → mask expose (write metal) → place parts on the gelled film → single bake. You keep the whole film, there is no developer and no plating.

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Why Foundries Care

• One photo, one bake, done: Eliminate resist develop, etch, plating, paste print, and reflow. Keep your contact aligner + oven; add pick-and-place.

• Invisible, corrosion-resistant routing: Metal is sealed under glass; open tiny pad windows only where needed.

• Native multilayer capabilities: Stack coats with ±10 µm alignment & ≤ 50 µm thickness per coat.

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How to use Step Collapse

1. Coat: 20 - 40 µm wet

2. Soft Bake: 50 - 70 °C for 1–3 min

3. Expose (write metal): UV @ 365 nm, 0.5 - 0.9 J cm⁻² 

4. Place: Pick and place SMD components and overlay them over the previously exposed traces.

5. Hard Bake: Ramp 2 - 4 °C / minute to 180 - 250 °C; hold for 30 - 60 min then cool naturally.

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What You Can Build

• Feature Sizes: 25 - 80 µm with contact masks

• Sheet Resistance: ~1 - 5 Ω/cm @ ~100 µm lines (dose-dependent)

• Layer Thickness: 50 µm

• Environmental Tolerance: 60 °C @ 90% RH