HDI means high density interconnection, this is different from conventional fabrication, it contains many different techniques from conventional PCB, such as staggered microvias, buried vias, skip vias, through hole vias, stacked microvias on buried vias.

Microvia is a blind hole with diameter ( ≤ 150 µm) having a pad diameter ( ≤ 350 µm) formed by either laser or mechanically drilling, wet/dry etching, photo imaging or conductive ink formation followed by a plating operation for product development.

Filled and capped microvias can be also placed directly in component solder lands reduces inductance in the power distribution network. Microvia in pad is advantageous for high speed signaling as well.

Emin knows many engineers are hesitant to use HDI designs as they don’t know if their PCB house can achieve the complexity of such difficult builds, or how cost effective it will be if the PCB shops can do it. This uncertainty keeps them stepping back a bit from HDI design.

Emin understands that manufacturing experience and appropriate equipment is the best, no risk, guarantee for HDI PCB manufacturing. Emin is extremely capable of these builds and has considerable experience using the latest technology, including: laser drill, mechanical drill, epoxy injection, vacuum lamination and horizontal copper plating. The equipment we are using is specifically designed and dedicated to HDI production. These machines are not commonly found, very expensive and take highly trained technicians to operate. By using these highly specialized machines properly and effectively, we create stable HDI builds with the upmost confidence and with the lowest possible failure rate. Because of this, our customers can find peace of mind and not worry about a fluctuating cost. Our process is stable, so your price is stable. Our excellent experience and equipment can ensure your HDI project is successful.

Through hole via: It is drilled through the PCB, you can use it to connect any layers, but you have less space for laying your traces as the hole goes entirely through the board and cannot be used for trace.

Staggered vias: For connecting multiple consecutive layers while staggering connections without drilling through the PCB, so you can save space to lay traces underneath.

Stacked vias: For connecting multiple consecutive layers directly on top of each other without drilling through the PCB. Unlike staggered vias, there is no space to lay traces underneath, but it will leave more areas open for laying other traces in your HDI PCBs.

Skip Vias: For connecting 2 non-consecutive layers skipping the connection of one to two layers between without drilling through the PCB. For example, if you want to connect layers 1 and 3, while skipping layer 2. You could also connect layers 1 and 4, skipping layers 2 and 3.

Buried Via: Only for connecting inner layers by means of a plated through via filled with epoxy, capped with copper plating. This is especially cost effective when you need to use stacked vias in too many layers. It balances the cost for both saving space on the PCB and designing a complex HDI project. Remember, microvias are expensive, too many stacked microvias can be more expensive.

Copper filled vias: When using the microvias that are filled and capped with copper for inner layers, you can stack another stacked via right on top; on the other hand, when using it for outer layers, it will be a direct pad that can be populated for surface mounting.