7 Things to Know about PCB Panelization Design Guidelines for Designers

Factors of PCB Panelization Design

There are several factors in the printed circuit board design. Below, we discuss three of them:

Circuit Board Design

The design of a PCB plays the most significant role in deciding the appropriate panelization method you are going to use. Generally, designers determine the ideal panelization method based on the size of clearance between components and the circuit board’s edge. They also look at the presence of edge-hanging elements.

Circuit Board Components

PCB components are the most vital parts of the entire panel. Each element has a distinct function. Features give the PCB the unique qualities that make it suitable for its intended purpose.

The type of components a designer chooses are as crucial as their placement. Sensitive components and connectors, in particular, play an essential role in the breakout. Some critical PCB components include the battery, resistors, LEDs, transistors, capacitors, inductors, diodes, and switches.  

PCB Material

The materials you use in a PCB can limit which panelization technique is most suitable. That is because some materials tend to splinter during the breakout process. Another critical factor is the board thickness. That is because skinny boards are more prone to break during assembly. Thick circuit boards, on the other hand, can prove challenging during the breakout process.

Understand PCB Panelization Design Guidelines

One of the biggest and costliest mistakes designers make is to leave essential PCB guidelines as an afterthought. Instead, they devote all their time to component selection and circuit design. Why is this a problem? Well, if you do not provide sufficient time and effort to the basics of PCB layout, you are likely to end up with a circuit design that performs poorly, both from the digital domain to the physical reality. The final design becomes problematic for the PCB manufacturer to fabricate.

So, how does the designer create a design that is both realistic on paper and in physical form? The first thing you need to know is there is not such a thing as a standard PCB. Every circuit board performs a unique function in the particular product you intend it for.

As a board designer, you will need to use a computer-aided design system with special design software to lay out your circuit pattern on the board. Often, the space between two electrical conducting paths is 0.04 inches or less. Using the design software, you will also need to layout the holes’ location for contact points and components. All this information is essential for the computer-controlled drilling machine during the manufacturing process.

As soon as the circuit pattern is complete, your computer-aided system prints out a negative image, also known as a mask, on a clear plastic sheet. This mask is the exact size of the circuit board. All areas that will not be part of the circuit pattern appear in black while the circuit pattern is clear.

PCB Panelization Design Method

Currently, there are various panelization methods in use. Let us look at three of the most common ones.

V-Score Panelization

V-Score of the panel, a single PCB separated by a V-shaped groove. Typically, the slots remove about a third of the circuit board’s thickness from both the board’s top and bottom sides using an angled blade.

Manufacturers commonly use a machine to complete the breakout process because the remaining part of the board between the top and the bottom grooves is considerably substantial. If they manually broke that part, it would put excessive stress on the board and surrounding components.

Solid Tab Panelization

To improve the overall strength of the PCB, designers can put solid tabs between each board. However, breaking this type of panel requires a laser cutting machine, a depaneling router, or a hook-shaped tool.

This panelization method is less common because the tools used for depaneling are not as efficient as manufacturers. The router, for instance, can cause vibration and dust. The laser cutter can be rather expensive and does not work well for thicker boards. The hook-bladed tool is prone to blade rotation.

Tab Routing Panelization

When PCB manufacturers can not feasibly use the V-groove method, they opt for the tab rooting technique. This method involves pre-cutting PCBs from the array and holding them in place on the circuit board using perforated tabs.

Manufacturers typically use three to five holes in the perforation patterns. Tab routing panelization is especially advantageous when it comes to designs that have edge-hanging tools. Besides, this method allows you to use hands instead of tools when it comes to breaking.  

Matters Needing Attention in PCB Panelization Design

We need to ensure that the PCB board has sufficient strength and function, and designers need to consider several factors. These include:

Gap

A gap of 0.05 inches between components and V-grooves is necessary to avoid affecting components during the cutting process. Where components are taller, this clearance may need to be bigger. If components have larger connection areas, place them further away from the groove. The solder joints can fracture due to the depanelization stress if they are too close to the V-groove.

Label Placement Problem

Tab placement is crucial when it comes to maintaining the integrity of the PCB array design. Place tabs every two to three inches along the board edge if you are using a five-hole perforated tab. For three-hole perforated tabs, place tabs every 1.5 inches. Make sure that the costs are large enough to support boards.

The Location of The Perforation

Avoid placing tab perforations at the center of the tab to avoid protrusions from the board sides. Instead, run them close to the PCB edge.

PCB Array Arrangement 

Always be sure to break tabs that are collinear at the same time when arranging PCBs. It ensures that break-lines are consistent throughout the array.

Problems that are Easy to Appear in the PCB Array

Even when the design of the PCB array is perfect, a few questions can appear during the breakout process. Below, we give you a few tips on countering these issues:

Manually Breaking Tabs

You can break a tab-routed panel using hand tools. To avoid any mistakes, use wide-nose pliers when bending a check in a break-line. Bend the cost in the opposite direction to fully separate it along the break-line.

Breaking with A Machine

The board is too thick to break by hand; it is best to use a cutting tool. In this case, use a depaneling router or a hook blade machine for the best results.

Manually Breaking V-Grooves

Designers can break V-scored panels manually depending on the board’s design and the closeness of components to the board. Follow the same procedure as that of manually breaking tabs.

Cutting V-Grooves

You can also break V-scored panels using a depaneling computer. The machine usually uses a blade that is relatively cheap and easy to maintain. The main drawback of this method is that board edges tend to be rougher.

Panel Wiring Method

Determining the appropriate puzzle method to use depends on several factors. These include:

Circuit Board Shape

The shape of the PCB you are designing determines the PCB panelization method you are going to use. For rectangular or square boards, use V-scoring. 

Edge Components

For PCBs that rely on edge-hanging components or components close to the edge, you may need to use a variation of tab-routing instead of V-scoring.

Edge Quality

Where edge quality is a factor, use tab routing. Though this process will leave some nubs of laminate, you can easily sand them off.

Time Spent

Generally, tab routing takes up more time and requires more labor to set up. In comparison, V-scoring takes up less time under the machines.

Waste of Materials

Where you are concerned about material waste, use V-scoring as it wastes less material compared to tab-routing. You, therefore, spend much less on the overall cost per board.

Other Considerations for PCB Panelization Design

Before we wind up this guide, let us look at some other factors you need to consider when it comes to PCB design. They include:

Quality Control

Throughout the design and manufacturing process of PCBs, you will need to make visual and electrical inspections. These inspections help you detect any flaws and fix them before it is too late. Some of these flaws include misplaced components, excess solder, and so on. As soon as the board is complete, you will also need to test them for functional performance to verify whether their output meets the desired limits.

Safety Considerations

Some of the materials you use to make PCBs contain lead, which is a toxic material. Fumes from the solder are also a health hazard. That is why it’s important to have the appropriate personal protection equipment at every correct PCB service provider. Thankfully, there are various PCB manufacturing process stage.

Summary

The PCB array design has a significant impact on the overall success and cost of the PCB manufacturing process. It is the reason designers must take the above design considerations very carefully. These guidelines give you a solid baseline for your future printed circuit board array designs. But perhaps more crucial to the success of your PCB design process is working with the right PCB manufacturer. That is where WellPCB comes in.

At WellPCB, we provide exceptional PCB panelization services to thousands of customers around the world. With our extensively experienced team of professionals, we can guarantee to take care of all your PCB panelization needs. Contact us today for a quote.