RK3399 core board

 
Notes:
1. This is a pure native design from LCSC EDA, with each wire pulled out individually, not imported.
2. It uses a six-layer PCB with LCSC's free process (JLC06161H-3313 lamination structure), and free prototyping is available!
3. It uses a core board + baseboard stacked design.
4. It is compatible with the OrangePi4 system. For stability, the design referenced the OrangePi board, which had relatively complete publicly available documentation at the time, and the documentation is generally universal.
5. Many compromises were made to use LCSC's free six-layer PCB process; some parts may not be entirely standard. Please forgive any inconsistencies.
6. The supporting baseboard is available at open source --> RK3399. Baseboard
 
features:

The RK3399 core board is a six-layer PCB, using the JLC06161H-3313 lamination structure, with a full through-hole design and a minimum hole diameter/outer diameter of 0.3/0.42mm.
The core board integrates eMMC, LPDDR3, RK808-D power management, and an NB680GD step-down chip.
The CPU's large cores, small cores, and GPU are powered by independent DC-DC power supplies, supporting DVFS dynamic voltage regulation.
The core board connects to the baseboard using two 120-pin board-to-board connectors and is secured at the four corners of the core board with four M2 screws.

 
 
Regarding soldering:
1. Soldering the core board is extremely difficult, requiring a hot air gun, soldering iron, and heating plate. A BGA soldering station and pick-and-place machine are even better.
2. A stencil must be opened before soldering. It's almost impossible to manually apply solder paste to each of the more than two thousand pads on the PCB surface.
3. I soldered two finished products; without a pick-and-place machine, it would be incredibly frustrating.