# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/DYqZc86ADMl
- **Gondola URL:** https://gondola.cc/posts/65777394-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/351ac23bd9.jpg
- **Posted:** 2026-05-23T01:20:34.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Most people think PCB fabrication requires a full chemical etching setup – ferric chloride, UV exposure units, transparency masks, the whole nine yards. But a diode laser and a bare copper clad board can skip half of that process entirely.

Here is what is actually happening at the physics level when you laser engrave copper for PCB prototyping:

	•	A focused laser beam (typically 450nm blue diode or 1064nm fiber) delivers energy density high enough to ablate or oxidize the copper surface
	•	Copper is one of the most reflective metals at visible wavelengths, which means blue diode lasers struggle with raw copper – reflectivity sits around 60-65% at 450nm
	•	Fiber lasers at 1064nm perform better but still face roughly 90% reflectivity on polished copper, which is why surface prep matters enormously
	•	Coating the copper with a dry erase marker, flat black spray paint, or commercial laser marking compounds drops that reflectivity dramatically, allowing the laser energy to couple into the surface and begin thermal ablation
	•	Once the coating absorbs enough energy to heat the copper underneath past its oxidation threshold (~200C in air), the process becomes self-sustaining because copper oxide is significantly less reflective than bare copper

The real engineering challenge is trace resolution. Consumer diode lasers with spot sizes around 0.08mm can reliably produce 10mil traces and spacing, which covers most through-hole and basic SMD work. But anything below 8mil – fine pitch QFP, BGA breakout – demands either a fiber laser with a galvo scanning head or you are back to photolithography.

What makes this method powerful for education and rapid prototyping is the iteration speed. Design in KiCad, export Gerber, convert to SVG, engrave, etch, drill – full cycle in under an hour with no chemical photography steps.

The copper you remove with the laser is not actually removed. It is oxidized and restructured. You still need a brief etch bath to clean the ablated regions down to bare substrate.

#stemantics #pcbdesign #laserfabrication #stemeducation #electronicsengineering

## Stats

- **Views:** 21,064
- **Likes:** 718
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## Tags

electronicsengineering, stemeducation, pcbdesign, stemantics, laserfabrication

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