Working for manufacturer engineering couple years. Sharing the manufacturing experience, skill, DFx, design, and information. Be care of this blog is personal share and content may not be 100% correctly.
In the electronics assembly manufacturing industry, what we commonly refer to as a “Mirrored Panel Board” or “Flipped Panel Board” actually comes in two types. The first type is a different-side mirrored panel board, where one board’s top side and another board’s bottom side appear on the same panel. The second type is a same-side mirrored panel board, where all boards are oriented on the same side but are mirrored left to right, such as in a “pdpd” layout pattern.
Manufacturers often request the “mirrored panel” design for two main reasons and benefits:
1. Optimizing SMT Assembly Line Efficiency
One quick way to judge the overall efficiency of an Surface Mount Assembly (SMA) line is to check if any machine is sitting idle. If we can eliminate idle time entirely, we could say that the SMT line is running at 100% efficiency.
But is it really that simple to achieve 100% efficiency? As SMT machines continue to improve in speed, and as components like SOC (System on a Chip) become more popular, the number of components on each PCB tends to decrease. However, solder paste printing machines have not seen the same improvements in speed or efficiency, which has led to a new bottleneck in SMT lines. Now, it’s common for the solder paste printer to work continuously without downtime, while other, more expensive machines are left waiting.
For example, let’s assume that it takes about 20 seconds to print solder paste on a panel printed circuit board (depending on its length). Meanwhile, the pick-and-place process that follows might only take 15 seconds to complete. This leaves a 5-second gap (=20s-15s) where the machine sits idle. It’s like buying a high-end Ferrari and then leaving it parked in the garage — wasted potential. Since each machine on an SMT line is a costly investment, it’s essential to maximize their usage and avoid idle time whenever possible to make the most out of these machines.
To address this, some manufacturers use panelization to increase the workload for the pick-and-place machines, significantly boosting their usage efficiency. However, they also need to avoid idle time on the solder paste printer. This led to the idea of mirrored panel boards, where different components or component counts appear on the same side of the board in a mirrored layout. This allows a long SMT line with multiple pick-and-place machines to work at full capacity.
Another key benefit of mirrored panel boards is that both the top and bottom sides can be populated on a single line, eliminating the time wasted on switching lines.
2. Eliminating unused space in panelization to improve utilization and reduce costs.
By saving space on panelization, we can improve the utilization of panelization, which helps save money. To achieve cost savings through high-volume production, most PCB manufacturers typically stock standard-sized boards, like 16.16″x16.16″, 18.32″x18.32″, 20.32″x20.32″, and so on. Some manufacturers may only buy certain standard sizes that are in higher demand, rather than stocking a full range of sizes.
For PCBs with irregular shapes, designing mirrored/flipped panels can sometimes allow you to fit an additional one or two individual boards onto the same panel. This will improves material usage and cuts costs.
The price of a PCB generally depends on the utilization rate of the panel. For example, if you use the same-sized panel, and Design A can only produce one board while Design B can produce two, then the cost of Board A would be double that of Board B. For more information, you can refer to the article “How to Choose the Number of PCB Panels.”
Unfortunately, although using mirrored panels has benefits like increased efficiency and cost savings, both types of mirrored panel designs come with their own drawbacks and limitations. For more details, see the article “The Limitations of Using “Mirrored Panels” or “Flipped Panels” in SMT.”
By saving space on panelization, we can improve the utilization of panelization, which helps save money. To achieve cost savings through high-volume production, most PCB manufacturers typically stock standard-sized boards, like 16.16″x16.16″, 18.32″x18.32″, 20.32″x20.32″, and so on. Some manufacturers may only buy certain standard sizes that are in higher demand, rather than stocking a full range of sizes.
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