A 32 Layer Printed Circuit boards are simply a multilayer PCB with 32 layers sandwiched together to function as one PCB. Manufacturing this kind of PCB cannot be done using conventional PCB Etching methods. This is because of the high precision expected. Advanced PCB Manufacturing methods are employed to ensure high quality and low electromagnetic radiation in the produced PCBs.
1.Preparing a Multilayer Layer PCB
Every professional PCB Design starts with a software design. The software design is the PCB Layout that gives rise to Gerber files and Drills files, which are very useful in PCB Fabrication. The onboard electronics are then assembled by an automated pick and place robot. For 32 Layer Printed Circuit Boards, assembly details are not only specified in the normal Bill of Materials (BOM) PCB Design files. A separate file containing a set of assembly instructions must accompany the software design files.
2.Technique Behind 32 Layer Printed Circuit Boards
To manufacture 32 Layer PCB, a Stack-Up made up of multiple PCB layers is constructed. This is made possible by the machine sandwiching multiple double layer PCBs with an insulating fiber-epoxy layer between every two double layer PCB. This insulating material is also called prepreg.
This implies that the basic building block of any multilayer PCB is a double-layer PCB. With this two-sided PCB fabrication technique at hand, and with more advanced machines to handle the increased complexity, fabrication of a 32 Layer or even a 50 Layer PCB is well achievable.
3.32 Layer Printed Circuit Boards Applications
Why do we need these 32 or 50 Layer PCBs? One of the obvious reasons is to efficiently embed all the required system electronics in one small-sized PCB. Even though components assembly is dedicated to top and bottom layers, it is possible to have components in between the Stack-up. The aerospace industry does a good job in making these complex PCB designs.
In any aerospace system, the target is to have very little or no electromagnetic emission as possible. Organizing a PCB during the design phase does a great job in arresting these emissions. Each PCB layer is usually dedicated to a certain function which is not conflicting with other layers. For example, middle layers could be used as supply power planes. While top and bottom layers are set aside for component placement.