Also as correctly pointed out by @rambaranwal, bare PCBs for each gadget, segment and industry is different and I believe B C C Fuba caters to all the most promising and flourishing sectors/spaces currently (including Automotive, power infrastructure, telecom, defense, medical, and railway). Moreover they cater to all the varied types of PCBs
As per their website,
And most importantly, they also have all the most important certifications (I could find for a PCB manufacturer),
Disc: Invested, very bullish therefore biased