via-in-pad in HDI PCB
The vias are a fundamental part of the interconnection between layers of a PCB. As the requirements of the electronics industry advance, the vias in a PCB need to be smaller and thinner. This has led to the development of HDI technology, which allows for more layers and higher component density on a PCB. There are multiple ways to achieve this high-density interconnect (HDI), such as stacked vias, blind vias, and buried vias. These different constructions have varying effects on the PCB’s overall routing density.
Via-in-pad is one of the most common constructions used in hdi pcb. It provides a direct connection from a component’s landing pad on the surface layer to an internal layer. This can help reduce manual routing time for complex projects. The resulting increase in routing density also allows for smaller components, which can be placed closer together on the board. This helps to decrease signal degradation and improve transmission speed, which can also reduce cost.
There are many types of vias that can be used on a PCB, and each has its own advantages and disadvantages. These include blind vias, buried vias, and filled plated microvias. Each type has its own unique attributes that contribute to the overall optimal performance of a circuit board or electronic product. For example, blind and buried vias are beneficial for increasing the density of a PCB, but they can cause problems with thermal conductivity. In addition, they can be prone to cracking due to the CTE difference between the plated over layer and the hole wall.
What is via-in-pad in HDI PCB?
Filling the vias with a conductive material is another way to add functionality to a PCB. This technique is used for specialized types of PCBs that require heat management of the components. This technique is called conductive via filling and uses silver or copper for the fill. It can be a more expensive option than non-conductive via fill, but it has many benefits. Conductive via filling prevents fractures between the plated over layer and the hole walls and can provide better impedance control.
There are two types of HDI structures: build-up/sequential laminations and any-layer structure/every layer interconnect (ELIC). In the sequential lamination structure, each layer is built up, drilled, plated, and filled before being laminated to the next layer. The any-layer structure, on the other hand, lets the conductors connect freely with a copper-filled stacked microvia structure in every layer. The any-layer structure is more efficient in terms of manufacturing, but it can lead to higher cost due to the complexity of the fabrication process and the basic material price for a conductive via fill.
Whether your design requires blind vias, buried vias, or via-in-pad, Huaqiu DFM can analyze your PCB with one click to detect any via-in-pad and provide suggestions for modifications to reduce the cost of your circuit board. The DFM tool can also provide you with bare board analysis, PCBA analysis, optimization recommendations, supply chain orders, and impedance calculations.
