Flex PCB Panelization: The Ultimate Guide

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Oakley Mae

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Manufacturing printed circuit boards (PCBs) is less challenging with the right tools and flex PCB panelization.

However, it gets tougher when dealing with small boards that may be unable to fit the production machinery conveyor width. What would you do?

Either you make your board bigger or adopt the industry-popular PCB panelization technique.

If you go with the first option, you will incur more costs and spend more time during production.

So, your best bet is to go with flex PCB panelization.   

This article helps you understand flex PCB panelization, including advantages, methods, and design considerations. Let’s get started!

Table of Contents

What’s Flex PCB Panelization?

Panelization involves massively manufacturing smaller circuit boards by connecting them as a single array.

Therefore, the boards will move easily and quickly in the assembly line.

Afterward, you can remove individual flex circuit boards from the array for installation or packaging, a process we refer to as depanelization. 

Manufacturers embrace panelization to reduce manufacturing costs and improve production efficiency.  

Advantages of Flex PCB Panelization

A flexible printed circuit board strip

(A flexible printed circuit board strip)

The advantages of flex PCB panelization include the following:

  • Mass production: PCB panelization saves you resources as you can mass-produce multiple small boards simultaneously. 
  • Ease of production: Working on an individual flex board at a time can be time-consuming when dealing with miniature boards. Consequently, it is better when you adopt a PCB panelization technique. 
  • Safety: Flex PCB panelization technique is safer as the larger board surface shields the boards from assembly-related shocks. 
  • Cost-effective: Generally, it is cheaper to manufacture flex-printed circuit boards using standard processing panels. It’s more so if your PCBs have specific shapes that may be challenging to fabricate individually. 
  • Reduces production time: You can process multiple boards quicker when you adopt PCB panelization than when working on a board at a time. 

Flex PCB Depanelization

An automated flex PCB manufacturing process

(An automated flex PCB manufacturing process)

After processing your panel, the next step involves depanelizing it to individually printed circuit boards.

In other words, flex PCB depanelization involves separating the array that holds multiple boards into smaller circuit boards.

The process is essential as you must separate the boards for individual use. 

Flex PCB Panelization Methods

Flex PCB panelization and depanelization methods are closely tied, as the former influences the latter.

Additionally, you cannot use a different depanelization method for boards you panelized through another method.

To understand more, here are the most common flex PCB panelization methods. 

V-Score Panelization

The panelization technique scores about one-third of a PCB thickness on the top and bottom sides.

Moreover, it’s similar to when you want to cut a block of material into two and start by chipping off the material in a V-shaped cut. 

Afterward, manufacturers use a machine to break the boards apart.

However, remember that printed circuit boards are rigid but delicate materials, and you shouldn’t hand-break them. 

Tab Routing Panelization

We use tab routing panelization for those boards that pose a challenge when depanelizing them.

Manufacturers cut slots into individual PCBs that connect to uncut sections known as tabs.

Additionally, we use the method to form panels consisting of oddly shaped PCBs.

Also, the method suits designs with components that hang on the PCB’s edges. 

Solid Tab Panelization

To improve the overall strength of a board, manufacturers opt for solid tab panelization.

With this method, they design panels with solid tabs between each smaller circuit board.

Consequently, you can use this method to form flex circuit board panels that are not rigid.

However, you’ll need a laser cutting machine or depaneling router for depanelization.

Design Considerations for Tab Routing Panelization

Engineers discuss flex PCB manufacturing

(Engineers discuss flex PCB manufacturing)

One important aspect of tab routing panelization is placing components closer to the edge.

Moreover, tab routing panelization works well for arrays comprising non-rectangular printed circuit boards.

Due to the above, you must design your array well to avoid damaging its functionality during depanelization.

Here are the critical design considerations:

Clearance

A significant problem with tab routing panelization is splintering which can happen when manufacturers place components too close to the tabs.

Consequently, we advise placing traces and components at a minimum distance of ⅛ inches from the tabs.

Furthermore, install crucial components, including capacitors, further away to keep them from damage. 

Placing Tabs

Tabs are the connection points between adjacent printed circuit boards that form a panel or array.

As a result, having too few will compromise your panel’s structural integrity.

On the other hand, having too many will be material waste and increase the production cost. 

Here’s a little secret to help you with your design.

Place tabs every 3 inches along the edge for 5-hole perforated tabs.

Moreover, place them every 1.5 inches for 3-hole perforated tabs. 

Placeholder or Knockouts

We use a placeholder or knockout to limit the challenges of the wave-solder process.

It’s true when the printed circuit boards have holes wider than 0.6 inches.

Additionally, we place placeholders in the middle of the board as these areas have a high chance of sagging.

Arrangement of the Panel

You must arrange your panel so you can break all tabs simultaneously.

Failure to do so will lead to irregular lines that may tear the board laminations. 

Placement of Perforations

Protrusions will sometimes be evident after separating your array into separate printed circuit boards.

Avoid placing tab perforations close to the tab’s middle to minimize such. In contrast, place them closer to the edges of the PCBs. 

V-Score Vs. Tab Routing PCB Panels

PCB panelization technique works well with circular PCBs

(PCB panelization technique works well with circular PCBs)

Your choice of a PCB routing method will mainly depend on the design that you’re working with. But that’s not to say that v-score routing works exclusively on boards that don’t support tab routing. Specifically, here are some factors that you should consider before settling on one of the methods. 

  • The board’s shape: For rectangular or square shapes, we recommend going with the v-score method. Conversely, go with tab routing if your array comprises oddly-shaped printed circuit boards. 
  • Edge components: If your printed circuit board has components that hang close to the edges, tab routing is better than v-scoring. However, ensure you don’t place these tabs close to the components.
  • Regarding the quality of the edges, select the tab routing method if your flex PCB must have smooth edges. Surprisingly, as much as the method leaves rough sections of laminates, you can easily sand them off. Conversely, the v-score method results in rough edges that may need more time to sand if it’s necessary to have smooth edges.
  • Time: The v-scoring method tends to be less time-consuming than tab routing. Therefore, be mindful of the method you adopt for maximum benefits. 
  • Waste: Finally, your chosen method can determine the number of waste materials. Surprisingly, the v-scoring method is ideal to save on material. Consequently, it is beneficial for projects with a higher cost per board.

FAQs

Why do you need software to process PCB panelization?

We need software like Altium and KiCad Panelization for the following reasons:

First, the software is faster than a human being, saving time. Additionally, they lead to better utilization rates of the pasting equipment.

Second, it improves the quality of surface-mounted technology while limiting the number of errors during production. 

Which software can you use for PCB panelization?

There is a lot of software that you can use for PCB panelization. However, use the following to achieve a high success rate. 

  • Altium Designer
  • Eagle PCB Design
  • KiCad
  • CircuitStudio

Conclusion

The flex PCB panelization relies on software that makes your work easier.

As seen in the sections above, some softwares include kiCad and CircuitStudio.

Surprisingly, these tools have different features that suit other panelization processes and not others. 

Therefore, review each one to get the one that suits you best and ensure you have the right tools to support the panelization process.