1. PCB blind vias are conductive holes that connect the surface and inner layers without penetrating the entire board.
2. Blind vias are found on the top and bottom surfaces of printed circuit boards, with a specified depth, serving to link the surface circuit with the inner circuit beneath.
3. The depth of these holes typically does not exceed a certain ratio relative to their aperture.
Blind vias are common in high-density interconnect (HDI) PCBs. The increased complexity of blind vias enables designers to improve signal integrity while reducing PCB size. The use of blind through-holes offers new routing options and choices, as valuable space is no longer required for through-holes that pass through unconnected layers.
Blind vias reduce parasitic capacitance by shortening the length and width of the vias. When a signal passes through a through-hole, signal attenuation and reflection occur. In high-speed design, signal discontinuity (capacitive and/or inductive discontinuity) caused by through-holes can compromise the integrity of the signal and power. Blind vias are an effective method for connecting high-speed (above 5 Gb/s) signal lines.
### The Process of Manufacturing PCB Blind Vias
1. **Sequential Lamination**
In this process, an extremely thin laminate undergoes all the production steps required to manufacture a double-sided PCB, including drilling, etching, and plating. Subsequently, this layer is stacked with all other layers of the PCB. The number of manufacturing steps involved in this method makes it quite expensive.
2. **Photo Defined**
This manufacturing process involves laminating photosensitive resin sheets onto the core. The pattern on the photosensitive film is exposed to light, hardening the material in the exposed areas. The material is then removed from the hole using an etching solution. Copper is plated on the holes and outer surface to create the outer layer of the PCB. When there are many blind vias on the PCB, this method can be cost-effective.
3. **Controlled Depth**
This method uses the same drilling process as through-hole drilling. It involves drilling a hole to a specific depth on the PCB and then plating it. While drilling is generally a cost driver, this method is the least expensive way to manufacture blind vias. However, the minimum width that can be drilled is limited by the smallest available drill bit size, typically 0.15 mm.
4. **Laser Drilled**
This process is completed after all layers of the PCB are laminated but before the outer layer is etched and laminated. By laser drilling copper and dielectric materials in one stage, a through hole can be created. This method is economically effective. To reduce costs and production time, laser drilling may be a better option than traditional through-holes.
### The Function of PCB Blind Vias
1. **Reduce Signal Interference**
In PCB circuit boards, signal transmission can be subject to various interferences, leading to distortion and transmission errors that affect the performance and stability of electronic products. Blind via PCBs reduce noise interference, optimize signal transmission paths, ensure signal speed and stability, and improve overall product performance.
2. **Increase Board Density and Number of Holes**
With advancements in electronic products, modern circuit boards are becoming denser and featuring more holes. Blind vias can increase the number of holes and make them more compact without using surface area, leading to higher PCB density. This structure allows more electronic components to be accommodated within the same PCB area, enhancing functionality and performance.
3. **Improve Stability of Electronic Products**
The stability of electronic products is a crucial indicator of product quality. The standardized layout of holes and signal paths in blind via PCBs ensures stable signal reception and transmission, effectively reducing product failure rates and enhancing the stability and reliability of electronic products.
PCB blind vias play a crucial role in the performance and stability of electronic products by reducing signal interference, increasing board density and number of holes, and improving product stability.
2. Blind vias are found on the top and bottom surfaces of printed circuit boards, with a specified depth, serving to link the surface circuit with the inner circuit beneath.
3. The depth of these holes typically does not exceed a certain ratio relative to their aperture.
Blind vias are common in high-density interconnect (HDI) PCBs. The increased complexity of blind vias enables designers to improve signal integrity while reducing PCB size. The use of blind through-holes offers new routing options and choices, as valuable space is no longer required for through-holes that pass through unconnected layers.
Blind vias reduce parasitic capacitance by shortening the length and width of the vias. When a signal passes through a through-hole, signal attenuation and reflection occur. In high-speed design, signal discontinuity (capacitive and/or inductive discontinuity) caused by through-holes can compromise the integrity of the signal and power. Blind vias are an effective method for connecting high-speed (above 5 Gb/s) signal lines.
### The Process of Manufacturing PCB Blind Vias
1. **Sequential Lamination**
In this process, an extremely thin laminate undergoes all the production steps required to manufacture a double-sided PCB, including drilling, etching, and plating. Subsequently, this layer is stacked with all other layers of the PCB. The number of manufacturing steps involved in this method makes it quite expensive.
2. **Photo Defined**
This manufacturing process involves laminating photosensitive resin sheets onto the core. The pattern on the photosensitive film is exposed to light, hardening the material in the exposed areas. The material is then removed from the hole using an etching solution. Copper is plated on the holes and outer surface to create the outer layer of the PCB. When there are many blind vias on the PCB, this method can be cost-effective.
3. **Controlled Depth**
This method uses the same drilling process as through-hole drilling. It involves drilling a hole to a specific depth on the PCB and then plating it. While drilling is generally a cost driver, this method is the least expensive way to manufacture blind vias. However, the minimum width that can be drilled is limited by the smallest available drill bit size, typically 0.15 mm.
4. **Laser Drilled**
This process is completed after all layers of the PCB are laminated but before the outer layer is etched and laminated. By laser drilling copper and dielectric materials in one stage, a through hole can be created. This method is economically effective. To reduce costs and production time, laser drilling may be a better option than traditional through-holes.
### The Function of PCB Blind Vias
1. **Reduce Signal Interference**
In PCB circuit boards, signal transmission can be subject to various interferences, leading to distortion and transmission errors that affect the performance and stability of electronic products. Blind via PCBs reduce noise interference, optimize signal transmission paths, ensure signal speed and stability, and improve overall product performance.
2. **Increase Board Density and Number of Holes**
With advancements in electronic products, modern circuit boards are becoming denser and featuring more holes. Blind vias can increase the number of holes and make them more compact without using surface area, leading to higher PCB density. This structure allows more electronic components to be accommodated within the same PCB area, enhancing functionality and performance.
3. **Improve Stability of Electronic Products**
The stability of electronic products is a crucial indicator of product quality. The standardized layout of holes and signal paths in blind via PCBs ensures stable signal reception and transmission, effectively reducing product failure rates and enhancing the stability and reliability of electronic products.
PCB blind vias play a crucial role in the performance and stability of electronic products by reducing signal interference, increasing board density and number of holes, and improving product stability.
