Today, the trend of increasingly compact electronic products requires three-dimensional design of Multilayer PCB. However, layer stacking raises new issues related to this design perspective. One of the problems is getting a high quality stack build for the project.

Stacking PCBS is becoming increasingly important as more and more complex printed circuits are produced with multiple layers.

Good PCB lamination design is essential to reduce the radiation of PCB circuits and associated circuits. On the contrary, a bad buildup may significantly increase radiation, which is harmful from a safety perspective.

What is PCB stacking?

The PCB lamination layers the insulation and copper of the PCB before the final layout design is completed. Developing effective stacking is a complex process. A PCB connects power and signals between physical devices, and the proper layering of the board material directly affects its function.

Why PCB lamination?

Developing PCB lamination is critical to designing efficient boards. PCB lamination has many benefits because the multi-layer structure improves energy distribution capacity, protects against electromagnetic interference, limits cross-interference, and supports high-speed signal transmission.

Although the primary purpose of stacking is to place multiple electronic circuits on a single board through multiple layers, the PCB stack structure also provides other important advantages. These measures include minimizing the vulnerability of the circuit board to external noise and reducing crosstalk and impedance problems in high-speed systems.

Good PCB lamination can also help ensure lower final production costs. PCB lamination can save time and money by maximizing efficiency and improving electromagnetic compatibility throughout the project.

Photo source: pixabay

Notes and rules for PCB lamination design

The layer number of low

Simple stacks may include four layers of PCBS, while more complex boards require professional sequential lamination. Although more complex, the higher levels allow designers more space to lay out without increasing the risk of encountering impossible solutions.

Typically, eight or more floors are required to achieve the optimal level placement and spacing to maximize functionality. Radiation can also be reduced by using a mass plane and a power plane on a multilayer panel.

Low layer

The arrangement of the copper and insulation layers that make up the circuit constitutes the PCB overlapping operation. To prevent PCB warping, make the cross section of the board symmetrical and balanced when arranging the layers. For example, in eight layers, the second and seventh layers should be similar in thickness to achieve optimal balance.

The signal layer should always be adjacent to the plane, while the power and mass planes are tightly coupled. It is best to use multiple grounding layers as they usually reduce radiation and ground impedance.

● Layer material type

The thermal, mechanical, and electrical properties of each substrate and how they interact are critical to selecting PCB lamination material choices.

The circuit board is usually composed of a strong fiberglass core, which provides the thickness and rigidity of the PCB. Some flexible PCBS may be made from flexible high temperature plastics.

The surface layer is a thin foil made of copper foil attached to the board. Copper is present on both sides of a double-sided PCB, and the thickness of the copper varies according to the number of layers of the PCB.

The top of the copper foil is covered with a blocking layer to make the copper trace in contact with other metals. This material is essential to help users avoid welding jumpers in the right place.

A screen printing layer is applied to the solder resist layer to add symbols, numbers and letters for easy assembly and a better understanding of the board.

● Determine wiring and through holes

Designers should route high-speed signals over intermediate layers between layers. This allows the ground plane to provide a shield that contains radiation emitted from orbit at high speed.

The placement of the signal level close to the plane level allows the return current to flow on adjacent planes, thus minimizing the return path inductance. There is not enough capacitance between the adjacent power supply and the grounding layer to provide decoupling below 500 MHz using standard construction techniques.

● Spacing between layers

As the capacitance decreases, a tight coupling between the signal and current return plane is critical. The power supply and grounding should also be tightly coupled.

Signal layers should always be close to each other even if they are in adjacent planes. Tight coupling and spacing between layers is critical for uninterrupted signaling and overall functionality.

conclusion

PCB lamination technology There are many different multi-layer PCB designs. When multiple layers are involved, a THREE-DIMENSIONAL approach that considers internal structure and surface layout must be combined. With the high operating speeds of modern circuits, careful PCB stacking must be performed to improve distribution capacity and limit interference. Poorly designed PCBS can reduce signal transmission, productivity, power transmission, and long-term reliability.