1. PCB vias are crucial components in multilayer circuit boards, categorized into three main types: blind vias, buried vias, and through vias.
2. Here’s how these vias differ:
(1) Blind hole: Located on the top and bottom surfaces of the circuit board, blind holes have a certain depth and are used to connect surface traces to inner layer traces. The depth and diameter of blind holes typically adhere to specific ratios to ensure manufacturability.
(2) Buried via: These vias are located entirely within the inner layers of the PCB and do not extend to the outer surfaces. Both blind and buried vias are prepared during the board’s layer buildup process. Through-holes drilled prior to lamination become inner layer connections, primarily used in multilayer PCBs. This configuration isn’t common in double-sided boards.
(3) Through hole: Extending completely from one layer to another, through-holes enable internal connections and serve as mounting holes for components. Due to their simpler implementation and cost-effectiveness, through-holes are typically preferred in printed circuit boards.
Advantages of Blind and Buried Vias
2. Here’s how these vias differ:
(1) Blind hole: Located on the top and bottom surfaces of the circuit board, blind holes have a certain depth and are used to connect surface traces to inner layer traces. The depth and diameter of blind holes typically adhere to specific ratios to ensure manufacturability.
(2) Buried via: These vias are located entirely within the inner layers of the PCB and do not extend to the outer surfaces. Both blind and buried vias are prepared during the board’s layer buildup process. Through-holes drilled prior to lamination become inner layer connections, primarily used in multilayer PCBs. This configuration isn’t common in double-sided boards.
(3) Through hole: Extending completely from one layer to another, through-holes enable internal connections and serve as mounting holes for components. Due to their simpler implementation and cost-effectiveness, through-holes are typically preferred in printed circuit boards.
Advantages of Blind and Buried Vias
1. The application of blind and buried vias can effectively reduce the size and number of circuit board layers, thereby improving electromagnetic compatibility, reducing customization costs, enhancing product characteristics. Through holes occupy significant wiring space.
2. Dense packing of numerous through-holes can hinder inner wiring of multi-layer circuit boards. When densely passing through power and ground layers, it not only disrupts their impedance characteristics but also jeopardizes their functionality.
3. The specific design of vias should align with customer product requirements; not all multilayer circuit boards necessitate blind or buried vias.
