What is Digital PCB Assembly?

The term digital refers to a type of electronic signal that is generated as opposed to being created naturally. At first thought, it may seem that since generation is a controlled process the possibilities for types of digital signals would be boundless. However, when the practicality of utilization is added, it quickly becomes clear that there should be limits placed on the form digital signals can take. Thus, digital signals are based on the simplest number system possible, which is binary.

Although the binary number system itself is simple, it can be used to make digital systems to any degree of complexity. Regardless of the level of complexity, digital systems are controllable and/or programmable. This quality is the impetus for the IoT and the present manufacturing revolution, Industry 4.0. These advantages of digitization can also be realized during the process of building the circuit boards that drive and control virtually all the products and systems that we use.

Let’s see how this is applied by examining digital PCB assembly contrasted with the more common PCB assembly process.

The PCB Assembly Process

Circuit board manufacturing can be divided into two types, each with different objectives. The first and arguably the most important is PCBA prototyping for development quality. This iterative process is essential for today’s complex PCBA designs to achieve the goals of reliable operation and the highest quality construction. The second type of manufacturing is production where the primary considerations are efficiency and cost-effectiveness. Whether low or high volume production, quality of process in terms of high-yield rates and board quality in terms of reliability in the field are also top priority objectives.

For prototyping and production, PCB assembly is the final stage of manufacturing. As such, the PCBA process has a profound effect on the boards that you receive from your contract manufacturer (CM). Just as is true for board fabrication, the assembly process does consist of a set of well-defined steps. However, it may be more informative to consider the process in light of the attributes listed below.

Major Attributes of PCB Assembly

• Accuracy
• Speed
• Precision
• Control
• Agility

Although not exhaustive, the list above highlights aspects that must be present for successful and efficient PCB assembly. Most assembly processes are at least partly automated; therefore, accurate and precise specifications are essential for the generation of the best boards. To accomplish this, some machines are programmable individually. The question is would the overall process benefit from digitization?

Conventional versus Digital PCB Assembly

The best PCB assembly depends on both the developer and the CM. And there are specific design for assembly (DFA) guidelines based upon your CM’s equipment and processes that should be followed for the best results. By doing so and with a capable conventional CM and automated processing, your boards should meet your requirements and expectations. However, turnaround time and board quality may suffer if your CM has to perform manually inspections or institute changes during a run. Likely drawbacks that you will not face if your CM institutes digital PCB assembly.

Digital PCB assembly refers to the utilization of software to control and monitor the steps of the assembly process. This is accomplished by having a digital thread that links the data transfer and reception points throughout the assembly process enabling real-time adjustments to maintain or improve process quality.

The use of the digital thread is critical as it ensures that all system equipment and processes are properly coordinated on the latest design specifications. To optimize the entire manufacturing process, the digital thread should include all entities involved in the board building process. This includes the developer, fabricator, component vendor, and assembler.