Are you looking to optimize the performance of your printed circuit board using a standard via size chart? One crucial board factor that often gets overlooked is the size of the vias. Vias play a critical role in connecting different printed circuit board layers (PCB). When used right, vias make smooth the flow of signals and power. That’s why Standard Via Size Chart knowledge is key.
In this blog, we’ll talk about standard via sizes and how they affect your designs. We’ll explore the benefits of using standardized dimensions. Whether you’re a flex PCB, rigid-flex PCB, or rigid PCB designer, understanding this standard via chart topic will empower you.
Join us as we help you make informed decisions for your projects. Get ready to take your designs to new heights with precise via sizing.
Why Bother Using a Standard Via Size Chart in Your PCB Design?
When it comes to PCB design, adhering to standard via sizes holds significant advantages. By not following established standards, you don’t get compatible designs, and the manufacturing feasibility of your PCB is unsure. Let’s explore why using the chart is so crucial.
Compatibility
First and foremost, using standard via sizes promotes compatibility. Standardization ensures that your PCBs can seamlessly integrate with other components, allowing for smooth and efficient circuitry connections. By utilizing well-defined via sizes found in the Standard Via Size Chart, you eliminate potential problems that arise when working with non-standard dimensions.
Feasibility Issue
Are you sure your PCB is feasible?
Moreover, standard via sizes enhance manufacturing feasibility. PCB fabrication processes are optimized for specific dimensions, enabling manufacturers to produce your boards more efficiently. Standardization streamlines the manufacturing workflow, reducing costs and improving turnaround time. It also simplifies materials sourcing, as various suppliers readily offer standard sizes.
Adhering to standard sizes benefits you from a broader ecosystem of tools, resources, and expertise. Design guidelines, simulation software, and manufacturing equipment are all developed with standard sizes in mind. These are followed when you refer to the Standard Via Size Chart. Via compatibility ensures that your design can be accurately analyzed, manufactured, and tested using industry-standard techniques.
Dependable PCBs can be made
In addition, standard via sizes enhance design reliability. These sizes have been thoroughly tested and proven to meet the requirements of various applications. Using non-standard sizes can introduce uncertainties and potential signal integrity issues, compromising the overall performance of your PCB.
In the next section, we’ll dive into the specifics of standard via size chart and how it empowers you to make informed decisions for your PCB designs.
Key Components of a Standard Via Size Chart
These elements include via size identification, drill size measurement, diameter specification, details for layer stacking, and additional guidelines. Information about vias concerning impedance, minimum clearance requirements, aspect ratios, and board sizes are also provided here.
Via Size Identification, Drill Size Measurement & Diameter Specification
A standard via size chart shows a comprehensive range of via sizes, each identified by its corresponding drill size or diameter. Here are some common via size ranges and their corresponding measurements:
Micro Vias
Drill Size: 0.006″ – 0.015″ (0.15 mm – 0.38 mm)
Diameter: 0.008″ – 0.020″ (0.20 mm – 0.51 mm)
Small Vias
Drill Size: 0.016″ – 0.025″ (0.41 mm – 0.64 mm)
Diameter: 0.022″ – 0.030″ (0.56 mm – 0.76 mm)
Medium Vias
Drill Size: 0.026″ – 0.040″ (0.66 mm – 1.02 mm)
Diameter: 0.032″ – 0.048″ (0.81 mm – 1.22 mm)
Large Vias
Drill Size: 0.041″ – 0.060″ (1.04 mm – 1.52 mm)
Diameter: 0.052″ – 0.072″ (1.32 mm – 1.83 mm)
Extra-Large Vias
Drill Size: 0.061″ – 0.100″ (1.55 mm – 2.54 mm)
Diameter: 0.078″ – 0.116″ (1.98 mm – 2.95 mm)
Note: the diameter refers to the width of the copper pad surrounding the drilled hole.
Layer Stacking
Layer Stacking
In multilayer PCBs, the Standard Via Size Chart includes information on the number of layers and their stacking order. The specification helps determine the appropriate via size based on the specific layer configuration.
Here’s an overview of the number of layers and their stacking order for different PCB designs:
Single Layer PCB layer Configuration: Only one copper layer on a substrate
Double-Sided PCB layer Configuration: Copper layers on both sides of the substrate
4-Layer PCB layer Configuration: Two internal copper layers sandwiched between the top and bottom layers
6-Layer PCB layer Configuration: Four internal copper layers sandwiched between the top and bottom layers
8-Layer PCB layer Configuration: Six internal copper layers sandwiched between the top and bottom layers
10-Layer PCB layer Configuration: Eight internal copper layers sandwiched between the top and bottom layers
The Role of Via in Multilayer PCBs
Internal copper layers are typically sandwiched between the top and bottom layers in constructing multilayer PCBs. These internal layers provide additional routing space for complex circuitry and allow for the transmission of signals between different layers. Via plays a crucial role in connecting these layers and establishing electrical connections.
The standard via size chart becomes valuable in this context as it provides specific measurements and dimensions for different via sizes. By referring to the chart, designers can determine the appropriate size based on the layer configuration of their PCB. For example, larger internal copper layers may require smaller vias to accommodate the increased density of connections.
The information readily available in a Standard Via Size Chart streamlines the design process. The result? Designers can select the correct via sizes to maintain signal integrity, electrical performance, and reliability in their multilayer PCB projects.
Additional Design Guidelines
Some charts provide additional guidelines and recommendations for various sizes. This may include maximum current-carrying capacity, impedance considerations, and other design constraints associated with specific via sizes. The most poignant of all is about:
Maximum Current-Carrying Capacity
This information helps designers select the appropriate size based on the current requirements of their circuit.
Via Size: 6 mils (0.006 inches) Maximum Current: 0.2 amperes
Via Size: 8 mils (0.008 inches) Maximum Current: 0.5 amperes
Via Size: 10 mils (0.01 inches) Maximum Current: 0.3 amperes
Via Size: 12 mils (0.012 inches) Maximum Current: 1 ampere
Via Size: 16 mils (0.016 inches) Maximum Current: 1.5 amperes
Via Size: 20 mils (0.02 inches) Maximum Current: 2 amperes
Via Size: 24 mils (0.024 inches) Maximum Current: 2.5 amperes
Via Size: 30 mils (0.03 inches) Maximum Current: 3 amperes
Via Size: 40 mils (0.04 inches) Maximum Current: 4 amperes
Via Size: 50 mils (0.05 inches) Maximum Current: 5 amperes
For High-Speed designs, there are additional considerations, so please check out this video:
Impedance Considerations
Some via sizes have specific impedance requirements, especially in high-speed or RF applications. Adhering to these recommendations in the Standard Via Size Chart ensures signal integrity and minimizes impedance mismatch issues.
Here are ten via sizes commonly used in high-speed or RF applications, along with their corresponding impedance requirements:
Via Size: 8 mils (0.008 inches); Impedance Requirement: 50 ohms
Via Size: 10 mils (0.01 inches); Impedance Requirement: 75 ohms
Via Size: 12 mils (0.012 inches); Impedance Requirement: 100 ohms
Via Size: 14 mils (0.014 inches); Impedance Requirement: 85 ohms
Via Size: 16 mils (0.016 inches); Impedance Requirement: 70 ohms
Via Size: 18 mils (0.018 inches); Impedance Requirement: 90 ohms
Via Size: 20 mils (0.02 inches); Impedance Requirement: 80 ohms
Via Size: 22 mils (0.022 inches); Impedance Requirement: 60 ohms
Via Size: 24 mils (0.024 inches); Impedance Requirement: 65 ohms
Via Size: 26 mils (0.026 inches); Impedance Requirement: 55 ohms
Minimum Clearance Requirements
Via Size: 8 mils (0.008 inches); Minimum Clearance: 8 mils
Via Size: 10 mils (0.01 inches); Minimum Clearance: 10 mils
Via Size: 12 mils (0.012 inches); Minimum Clearance: 12 mils
Via Size: 14 mils (0.014 inches); Minimum Clearance: 14 mils
Via Size: 16 mils (0.016 inches); Minimum Clearance: 16 mils
Via Size: 18 mils (0.018 inches); Minimum Clearance: 18 mils
Via Size: 20 mils (0.02 inches); Minimum Clearance: 20 mils
Via Size: 22 mils (0.022 inches); Minimum Clearance: 22 mils
Via Size: 24 mils (0.024 inches); Minimum Clearance: 24 mils
Via Size: 26 mils (0.026 inches); Minimum Clearance: 26 mils
Via sizes and Aspect Ratios
A 1:1 aspect ratio is commonly used.
Consider the following examples:
Via Size: 8 mils (0.008 inches); Aspect Ratio: 1:1
Via Size: 10 mils (0.01 inches); Aspect Ratio: 1:1
Via Size: 12 mils (0.012 inches); Aspect Ratio: 1:1
Via Size: 14 mils (0.014 inches); Aspect Ratio: 1:1
Non-1:1 aspect ratios
However, some designs may require different ratios based on factors such as board thickness, layer count, and manufacturing capabilities. Here are a few examples of non-1:1 aspect ratios:
Via Size: 10 mils (0.01 inches); Aspect Ratio: 1:2
Via Size: 12 mils (0.012 inches); Aspect Ratio: 1:3
Via Size: 14 mils (0.014 inches); Aspect Ratio: 1:4
Via Size: 16 mils (0.016 inches); Aspect Ratio: 1:5
Via Size: 18 mils (0.018 inches); Aspect Ratio: 1:6
Via Size: 20 mils (0.02 inches); Aspect Ratio: 1:7
Via Size: 22 mils (0.022 inches); Aspect Ratio: 1:8
Via Size: 24 mils (0.024 inches); Aspect Ratio: 1:9
Via Size: 26 mils (0.026 inches); Aspect Ratio: 1:10
Via Size: 28 mils (0.028 inches); Aspect Ratio: 1:11
Board Thickness
Limitations related to board thickness
Remember that the particular restrictions on board thickness can change depending on the aspect ratio, copper plating method, and production capacity, among other things.
Via Size 12 mils (0.012 inches) Limitation
Suitable for thinner boards, they have limitations in thicker boards due to plating and reliability concerns.
Via Size: 14 mils (0.014 inches) Limitation
Versatile size suits a wide range of board thicknesses but may have limitations in very thin or thick boards.
H5: Via Size: 16 mils (0.016 inches) Limitation
Generally suitable for moderate board thicknesses, they have limitations in very thin or thick boards.
Via Size: 20 mils (0.02 inches) Limitation
Quite suitable for a wide range of board thicknesses, with fewer limitations compared to smaller via sizes.
Via Size: 24 mils (0.024 inches) Limitation
OK for thicker boards, but have limitations in very thin boards due to aspect ratio constraints.
Via Size: 28 mils (0.028 inches) Limitation
Generally suitable for thicker boards, they have limitations in very thin boards due to aspect ratio constraints.
Via Size: 32 mils (0.032 inches) Limitation
Used in thicker boards, with fewer limitations compared to smaller via sizes.
Via Size: 36 mils (0.036 inches) Limitation
Likely suitable for thicker boards but may have limitations in very thin boards due to aspect ratio constraints.
Via Size: 40 mils (0.04 inches) Limitation
For thicker boards, with fewer limitations compared to smaller via sizes.
Via Size: 48 mils (0.048 inches) Limitation
It’s good for thicker boards but may not be good for very thin boards due to aspect ratio constraints.
Now that we have gathered all the information you need, how do you use all those numbers? Read on because the next section will guide you.
Interpreting
How to Interpret the Measurements in the Via Size Chart?
Understanding how to read and interpret the numerical values is essential when you come across the Standard Via Size Chart. Here are some key points to help you navigate the chart effectively:
How to make sense of the numerical values in the chart
First, we will name the term, then we will explain it.
Via Size Representation
The via size is typically presented in terms of either the drill size or the diameter. In the Standard Via Size Chart, the drill size refers to the diameter of the hole drilled for the via, while the diameter represents the actual size of the via itself.
Here are a few examples to illustrate the relationship between drill size and via diameter:
- For a 12-mil (0.012 inches) drill size, the resulting via diameter is around 10 mils (0.01 inches).
- If you have a 20-mil (0.02 inches) drill size, the resulting via diameter would be approximately 18 mils (0.018 inches).
- A 6-mil (0.006 inches) drill size would correspond to a via diameter of around 4 mils (0.004 inches).
Measurement Units
The chart will specify the measurement units used for the via sizes. Common units include mils (thousandths of an inch) and millimeters. Ensure you are familiar with the chosen unit to interpret the values accurately.
Here are some specific examples to help you understand the concept:
If the chart uses mils as the measurement unit, you will see values such as 10 mils, 12 mils, or 20 mils. For example, a via size of 10 mils corresponds to approximately 0.01 inches or 0.254 millimeters.
If the chart uses millimeters, the values will be specified accordingly. You may come across measurements like 0.2 mm, 0.3 mm, or 0.5 mm for via sizes. For instance, a via size of 0.3 mm is approximately equal to 11.81 mils or 0.01181 inches.
Corresponding Values
A list of a range of via sizes, along with their corresponding numerical values, is provided in the chart. For example, a via size of 12 mils (0.012 inches) indicates that the hole diameter or via diameter measures 12 mils or 0.012 inches.
Identifying Suitable Via Sizes
As you review the chart, pay attention to the specific via sizes that fall within the acceptable range for your PCB design. This will depend on the board thickness, copper plating requirements, and manufacturing capabilities.
Matching Design Requirements
Complement your design requirements with the appropriate via sizes using the Standard Via Size Chart. Consider signal integrity, current carrying capacity, and board space constraints to select your application’s optimal via size.
Remember, the Standard Via Size Chart is a valuable reference tool, enabling you to make informed decisions about via selection in your PCB design. It’s always recommended to consult with the PCB manufacturer or Flex PCB maker for specific limitations based on your unique board requirements.
PCB Drills
What is drill size’s or diameter’s significance in determining the via size?
Here’s why:
Conductor Connectivity
The drill size determines the diameter of the hole drilled through the PCB. This hole serves as a conduit for the via, allowing electrical connections to be made between different layers of the circuit. The contact area between the via and the conductive substance is directly impacted by the hole’s diameter, ensuring optimal electrical communication.
Signal Integrity
In high-speed PCB designs, maintaining signal integrity is paramount. The drill size affects the impedance of the via, which can impact signal quality. By selecting the appropriate drill size, you can match the transmission line’s characteristic impedance, minimizing signal degradation and reflections.
Current Carrying Capacity
Larger drill sizes provide more space for copper plating within the via, increasing its current carrying capacity. This is crucial for power traces or components that require higher current levels. By selecting a suitable drill size, you can ensure the via can handle the desired current without overheating or causing electrical failures.
Design-Related Factors
The drill size also influences the amount of space required on the PCB. Smaller drill sizes result in smaller vias, allowing for higher-density routing and efficient space utilization. Conversely, larger drill sizes may be necessary for high-power applications but occupy more board space.
An example to illustrate drill size/diameter significance in determining the via size
To illustrate the significance of drill size, consider an example: A high-speed design with controlled impedance may require a 10-mil (0.01 inches) drill size to achieve the desired signal integrity. In contrast, a power-intensive circuit might require a 20-mil (0.02 inches) drill size to accommodate the necessary current carrying capacity.
By understanding the impact of drill size or diameter on via performance, you can make informed decisions during the PCB design process. Careful consideration of these factors ensures your vias’ optimal functionality, signal integrity, and reliability within the circuitry.
Troubleshooting
Troubleshooting and Making Adjustments When Necessary Using Standard Via Size Chart
Imagine you’re manufacturing your PCB, and suddenly you encounter some challenges. Your manufacturer may tell you that the chosen via sizes are incompatible with their manufacturing capabilities. Or you may notice signal integrity issues causing data errors or thermal problems leading to overheating.
Don’t worry! The Standard Via Size Chart comes to your rescue, providing a roadmap to troubleshoot and make necessary adjustments.
Signal problems
Signal integrity is crucial for maintaining data integrity and minimizing noise in your PCB. If you encounter signal integrity issues, adjust the via sizes to improve impedance matching and reduce signal degradation.
Overheating issues
Thermal considerations are vital, especially when dealing with high-power applications. If you notice temperature-related challenges, adjust the via sizes and their placement. Then, you can cool down your components and prevent any potential damage from overheating.
With the invaluable assistance of the Standard Via Size Chart, you can troubleshoot, adjust, and optimize your PCB design for seamless manufacturing, robust signal integrity, efficient thermal management, and adaptability to design changes. However, finding a reliable partner to materialize your design is equally important. That’s where MV Flex comes into the picture.
MV Flex Circuit Helps You with Standard Via Size Chart
We understand the significance of the standard via size chart in optimizing your PCB design.
The MV Flex Circuit team is here to guide you through the complexities of via sizes, ensuring that your design meets the highest performance, reliability, and manufacturability standards. Our expertise in flex and rigid-flex PCB solutions allows us to continuously integrate the recommended via sizes into your design.
We’ll consider signal integrity, current carrying capacity, and board space constraints.
Our skilled PCB engineers know the latest industry standards and specifications, including IPC guidelines.
Whether you need assistance selecting the right size, troubleshooting issues, or making adjustments, we are here to help!
So please, contact MV Flex Circuit now!
