Disadvantages of high-density interconnected PCB boards

The value of NDI impedance focuses on pattern transfer (complexity of patterns) and pattern electroplating process.
The quantity and quality are abnormal, especially the high-density circuit part of the HDI PCB board has a slower etch rate than the isolation line, which causes the isolation line to be over-etched.
When the entire HDI board is etched after electroplating, a large area of ​​copper on the PCB circuit board will be etched away, which increases the production cost. At the same time, a large amount of copper ions enter the waste liquid after etching, causing environmental pollution and difficulty in recycling.