Printed circuit boards (PCBs) are the vital innards of any electronic device. Since their inception during the 1930s, PCBs have seen advances in complexity and operational capacity. They have been shrunk from the size of a desktop to smaller than the cap of a pen. PCB’s potential is endless, with new developments bringing new, creative ways to use them each year.
With so much variation to be found, every PCB assembler or manufacturer must understand the difference between them. Simple PCBs are made using a single layer of substrate board with components secured using solder. More complex boards use components mounted on multiple layers of substrate.
Then there are different ways to perform PCB assemblies, such as high volume and low volume assembly. Today, we’ll take a closer look at these assembly types and what is the more suitable option for your production run.
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What are high and low volume PCBs?
The terms “high volume” and “low volume” refer mainly to the number of boards produced in a single assembly.
In numerical terms, high-volume PCB manufacturing usually requires at least 1,000 boards to be assembled in a single order. On the other hand, low-volume PCB manufacturing will see fewer than 1,000 boards produced and as low as 250.
The number of boards being produced mainly depends on the customer’s requirements. These requirements are decided by both the nature of the boards and the environment in which assemblers need them. You can order boards to fit a specific number of electronic products or ask the board maker to create a surplus of parts for future work.
Benefits of High-Volume PCB
A high-volume PCB production order is required for any job requiring between 1,000 and 100,000 boards. Assemblers will turn to it if they need:
- Quick turnaround for large orders – It is significantly faster to mass-produce an order of 3,000 PCB units than to produce the same number over multiple low-volume runs. Producing more boards under a single production run reduces time lost in prototyping, increasing turnaround.
- A means of meeting market demand – During changes in existing prototype designs and the advent of new technology, high-volume PCB production gets manufacturers out quicker. This makes it the go-to for companies looking to get ahead of potential competition.
- Greater automation – With fewer changes being made during production, high-volume production is much quicker and suffers fewer setbacks.
- Lower production costs – Losing less time and money to prototypes and testing allows fewer lost components and higher output. The level of consistency also results in fewer defects and failed boards.
Typically, high-volume PCB production options are chosen for the mass production of consumer electronics. Building large numbers in one go is much easier and quicker than making them in smaller batches. The simple uniformity of each unit allows for more boards to be built without alteration and interruption.
Benefits of Low-Volume PCB
Compared to high-volume PCB production, low-volume PCB is for far smaller manufacturing batches. Opting for low-volume production is not ideal for mass production; however, it works well during the designing and prototyping stages.
Design schematics will often change when it comes to the initial stages of producing a new PCB as flaws and errors become apparent. Assembling boards in smaller batches allows manufacturers to create test batches of new designs. This happens without committing vast resources such as time and components to them.
This happens because each stage of a low-volume production line is much more stringent in testing and troubleshooting. As such, low-volume production is split into two distinct types:
Design for Manufacturing (DFM)
DFM orders focus on the basic designs of the boards to determine aspects such as the required components and board dimensions. At this stage, the manufacturing process lists will be compiled, as well as assembly drawings and circuit diagram representations drawn. Manufacturers can also determine the efficacy of the board’s production and whether the design will work. This can help reduce the possibility of manufacturing errors and downtime before they occur.
Design for Testing (DFT)
With DFT orders, clients can have a more hands-on approach to the PCB assembly process. Design plans are discussed heavily between the client and the manufacturer, with each stage of development offering new chances to see issues and errors as they arise. These issues are then corrected so that the next assemblage is more capable and closer to the final design specifications. It also allows designers and manufacturers to ensure that the finished product meets all regulations and processing requirements.
Once the plans are in place, the actual manufacturing process runs in two ways. These are determined by the available production time or to allow for further testing and alterations:
- Parallel Prototyping – With this, multiple board designs are manufactured simultaneously, each featuring small variations to test different aspects of the board. These changes allow many different designs to be created in tandem, giving a wider range of testing prototypes to narrow down in one go. It greatly reduces the manufacturing time to do this but runs the risk of not finding every potential issue until several rounds are completed.
- Sequential Prototyping – This way, the production focuses on one design at a time, with testing occurring after each phase. The tests determine the efficacy of the board and what alterations must happen between each batch. While it will take longer to produce boards this way, it allows designers to correct issues as they arise, reducing the potential overall production time.
PCBs created in low-volume production batches are used for more specialized equipment. Unfortunately, it is more expensive to produce boards in lower numbers, but it is a necessity when the need for perfection is high.
High-Volume PCB vs. Low-Volume PCB
Choosing whether to have a board produced in high volume or low volume is a matter of process. In contrast, the difference between the two types is simple on the surface; below that, the processes and uses are vastly different.
Low-volume production is key for devices needing stringent testing and altering, while those already doing what they need can be mass-produced. Putting a brand-new, untested design into high-volume production would be messy and potentially disastrous if problems are left unresolved. Overall, the former is a more suitable choice for most production runs—ask your EMS PCB assembly company if they deal in low-volume PCB to get started.