What is a PCB Panel?

A PCB (Printed Circuit Board) panel, also known as a PCB array or PCB matrix, is a manufacturing method where multiple identical PCBs are fabricated together on a single larger board. This approach is commonly used in PCB Production to optimize the manufacturing process, reduce costs, and improve efficiency.

Advantages of Using PCB Panels

1. Cost reduction: Fabricating multiple PCBs on a single panel reduces the overall cost per unit, as it minimizes material waste and setup time.
2. Increased efficiency: Panelization allows for the simultaneous production of multiple PCBs, reducing the total manufacturing time.
3. Consistent quality: Since all PCBs on a panel undergo the same manufacturing process, they tend to have consistent quality and fewer variations.
4. Simplified handling: Panels are easier to handle, transport, and store compared to individual PCBs.

PCB Panel Design Considerations

When designing a PCB panel, several factors need to be considered to ensure optimal results:

Panel Size and Layout

The panel size and layout should be determined based on the following factors:

1. PCB dimensions: The size and shape of the individual PCBs will dictate the panel layout and the number of PCBs that can fit on a single panel.
2. Manufacturing equipment: The panel size must be compatible with the manufacturing equipment, such as the PCB router, pick-and-place machines, and reflow ovens.
3. Material utilization: Aim to maximize the number of PCBs per panel while minimizing material waste.

Standard Panel Sizes	Dimensions (mm)
Small	200 x 200
Medium	300 x 300
Large	450 x 450
Extra Large	600 x 600

Panelization Methods

There are two main methods for panelizing PCBs:

1. V-scoring: V-shaped grooves are cut partway through the panel, allowing the individual PCBs to be easily broken apart after assembly. This method is suitable for smaller PCBs and low-volume production.
2. Tab-routing: Individual PCBs are connected to the main panel using small tabs, which are milled away after assembly. Tab-routing is more suitable for larger PCBs and high-volume production.

Tooling and Fiducial Marks

To ensure accurate and consistent manufacturing, tooling and fiducial marks should be included in the panel design:

1. Tooling holes: Used for aligning and securing the panel during the manufacturing process.
2. Fiducial marks: Used as reference points for automated assembly equipment, ensuring precise component placement.

Spacing and Clearance

Proper spacing and clearance between individual PCBs on the panel are essential to avoid manufacturing issues:

1. Minimum spacing: Ensure that there is sufficient space between PCBs to prevent short circuits and allow for clean breakaway or tab-routing.
2. Edge clearance: Maintain adequate clearance between the PCBs and the panel edges to avoid damage during handling and manufacturing.

Spacing Type	Recommended Distance (mm)
PCB to PCB	2 – 3
PCB to Edge	3 – 5

Assembly and Testing

Panel-based Assembly

When assembling PCBs in a panel, consider the following:

1. Component placement: Ensure that components are placed accurately and consistently across all PCBs on the panel.
2. Solder paste application: Use a solder paste stencil designed for the panel layout to ensure even solder paste distribution.
3. Reflow soldering: Adjust reflow oven settings to accommodate the larger thermal mass of the panel compared to individual PCBs.

Testing and Inspection

After assembly, the PCBs on the panel should undergo thorough testing and inspection:

1. Automated Optical Inspection (AOI): Use AOI to detect soldering defects, component placement issues, and other visible defects.
2. In-Circuit Testing (ICT): Perform electrical tests on the assembled PCBs to verify functionality and identify any shorts, opens, or component failures.
3. Functional testing: Test the individual PCBs to ensure they meet the required performance specifications.

Depanelization

Once the assembled PCBs have passed testing and inspection, they need to be separated from the panel:

1. V-scored panels: Apply pressure along the v-scored lines to break the PCBs away from the panel.
2. Tab-routed panels: Use a specialized depanelization machine or manual tools to remove the tabs and separate the PCBs.

Best Practices for PCB Panel Design

1. Keep the panel design simple and symmetrical to minimize warping and ensure even heating during reflow soldering.
2. Use a uniform PCB layout across the panel to maintain consistent quality and performance.
3. Include test coupons on the panel for quality control purposes.
4. Follow the manufacturer’s guidelines for panel dimensions, spacing, and clearances.
5. Consider the assembly and testing requirements when designing the panel layout.

Frequently Asked Questions (FAQ)

1. What is the optimal number of PCBs per panel?

The optimal number of PCBs per panel depends on various factors, such as the PCB size, panel size, and manufacturing equipment capabilities. In general, aim to maximize the number of PCBs while maintaining proper spacing and clearances and minimizing material waste.

2. Can different PCB designs be combined on a single panel?

While it is possible to combine different PCB designs on a single panel, it is generally not recommended. Mixing different designs can lead to issues with component placement, soldering, and testing. It is best to use separate panels for each unique PCB design.

3. What is the minimum recommended spacing between PCBs on a panel?

The minimum recommended spacing between PCBs on a panel is typically 2-3mm. This allows for clean breakaway or tab-routing and prevents short circuits between adjacent PCBs.

4. How do I choose between v-scoring and tab-routing for my PCB panel?

The choice between v-scoring and tab-routing depends on factors such as the PCB size, production volume, and depanelization equipment available. V-scoring is suitable for smaller PCBs and lower volumes, while tab-routing is better for larger PCBs and higher volumes.

5. Can PCB panels be used for both prototype and production runs?

Yes, PCB panels can be used for both prototype and production runs. However, the panel layout and design may differ between the two. Prototype panels may have fewer PCBs and more space for test coupons, while production panels aim to maximize the number of PCBs per panel for cost efficiency.

In conclusion, delivering PCBs in a panel offers numerous advantages, including cost reduction, increased efficiency, and consistent quality. By carefully considering panel size, layout, panelization methods, and assembly requirements, designers can create optimal PCB panels that streamline the manufacturing process and ensure the best possible results.