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If PCB is compared to a city, pcb delaminationdesign is the steel skeleton of a skyscraper - it determines the "anti-interference ability", "heat dissipation efficiency" and even "lifespan" of the entire board.
Here is a real example:
A team designed a 6-layer camera motherboard. During the test, it was found that the image frequently had noise. The engineer repeatedly adjusted the circuit to no avail. Finally, it was found that the power layer was too far away from the ground plane, resulting in a long high-frequency current return path. The problem was finally solved by optimizing the stacking structure.
Multilayer PCB Printed Circuit Board is a composite structure circuit board formed by alternately stacking multiple conductive layers and insulating dielectric layers. Its purpose is not "more layers are better", but to solve a series of engineering problems such as wiring congestion, signal integrity, anti-interference ability, power distribution, etc.
For example, in high-speed digital signal systems, the wiring length and the distribution of routing layers will greatly affect the timing and integrity of the signal. Reasonable multi-layer design can allocate exclusive channels for high-speed signals and isolate noise sources with ground layers, thereby achieving more stable system performance.
Multilayer ≠ high-end, but reasonable layering is the key
In actual engineering, increasing the number of layers will bring greater wiring freedom, but it also means higher manufacturing costs, more complex stacking design and more stringent board control. For example: a complex embedded system design does not necessarily require an 8-layer board. Perhaps by optimizing the layout and using blind buried hole technology, a 4-layer board can also do the job.
Conclusion: PCB layering is not just "the number of layers", but the art of using space for performance.
pcb delamination
2. Three core principles of layered design
1. Signal layer: Is your wiring really "on the right track"?
Novice misunderstanding: Blindly pursue wiring density and squeeze high-speed signal lines and power lines into the same layer. Bloody lesson: A high-speed ADC board has a 30% sampling error rate due to power supply noise coupling to the clock signal.
Golden rules:
High-speed signals should be placed close to the ground plane first (shorten the return path)
The routing directions of adjacent layers are perpendicular (reduce crosstalk, imagine a cross-shaped road network)
It is strictly forbidden to route key signals across the partition area (discontinuous ground plane = signal jumps off a cliff)
2. Power/ground plane: 99% of EMC problems come from here Counterintuitive truth: The main function of the power layer is not to supply power, but to provide a low-impedance loop for high-frequency signals! Fatal operation: Treat the power layer as a "universal garbage dump" and arbitrarily slot and split it. Practical skills: The power and ground planes must be adjacent (capacitive effect reduces impedance) Avoid the ground plane being split by signal lines (refer to the figure below "Complete ground plane vs. fragmented ground plane") Sensitive circuit areas are divided into separate ground islands (such as the analog ground of ADC)
The essential role of multilayer boards
Several core principles for engineering layer selection:
Functional requirements first: multilayer is mainly to meet the design requirements of high speed, high density and high reliability, not a simple "stack".
Signal integrity and power integrity are equally important: arrange the power layer and ground layer positions reasonably to achieve impedance continuity and low noise as much as possible.
Structural symmetry: pay attention to the balance between thermal stress and mechanical strength of the stacked structure to avoid warping due to asymmetry.
Cost control: the more layers there are, the higher the material cost, processing difficulty, and test complexity will be, and the use scenario and budget need to be weighed.
Trend observation: high and multi-layer are becoming mainstream
In high-end applications such as 5G communications, AI servers, and smart cars, 12-layer, 16-layer, and even 24-layer HDI boards are common. These applications require high-speed signal channels, fine power networks, and stable structural support. While multi-layer design has become a trend, it also puts higher demands on the process capabilities of PCB manufacturers.
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In a word, pcb delamination is an important part in pcb design!