#Photoresist

Tokyo Ohka Kogyo is No. 1 in photoresist with a 24.7% share and No. 2 in EUV resist with 28%. How a 1936 maker of coal-lamp battery material became a chokepoint in the AI chip supply chain.

Not TSMC, not ASML. A Japanese chemical maker with ~$240M in sales quietly supplies about 70% of the world's photoresist sensitizer—the ingredient inside the ingredient that prints every advanced chip.