To reduce the difficulty of your purchasing, here are the trusted PCB manufacturers.
They must have the following requirements: 1. Own your own factory and provide sufficient certification. 2. It can provide instant quotes. 3. There is no bad credit history in the Chinese market. 4. Cooperation has lasted more than one year without any dispute.
For any referral companies you see, we talked to the CEO and visited the factory. There will be some videos.