Optimizing the Manufacturing Process for Different Types of PCBs

Everyone, well almost everyone, is familiar with the famous mass-energy equation, E=mc2. Albert Einstein, who came up with the equation opened the door for many developments with his work in quantum physics. However, in scientific circles, he is probably best known for the Theory of Relativity, which is actually a combination of two theories: the Theory of Special Relativity and the Theory of General Relativity. The former of these can be applied to any number of phenomena, some of which are quite basic. Take, for example, the well-known passenger on a train example. From the perspective of Passenger A, sitting behind Passenger B, it seems like Passenger B is not moving at all. However, an observer sitting outside of the train on the platform can affirm that both passengers are traveling at the speed of the train. This simple case illustrates that the parameters of an occurrence are dependent upon the reference frame of the observer, or more succinctly, everything is relative.

Different Types of PCBs

Relativity is also an important aspect of circuit board development. In fact, board designs may be classified in what seems to be an infinite number of ways. Fortunately, there is a finite set of different types of PCBs that can be considered common. And these types can be further grouped into smaller more manageable taxonomies for which we can define specific design considerations that can be used to optimize the manufacturing process. Let’s take a look at some common different types of PCBs and their taxonomies and the best way to manufacture these boards according to their specific classification.

What are the Different Types of PCBs?

Printed circuit boards are liberally characterized based on a large number of attributes. These include their functionality, application, operational environment, number of layers, locations of components, and many others too numerous to list here. It is possible, however, to enumerate a listing of common PCB types and classify them according to like properties or attributes as shown below.

DIFFERENT TYPES OF PCBs
Taxonomies	PCB Types
Mechanical Construction	Rigid, Rigid/Flex, Flex
Stackup	Single-sided, Double-sided, Multilayer
Application	Commercial, Critical, Medical, Automotive, Industrial
Signals and Power	High Speed, High Current, High Voltage, High Power

The listing in the table above is not exhaustive. Yet, it does provide us with a manageable group of different types of PCBs for which we can define specific design tips for optimization of the manufacturing process.

Optimizing PCBA Manufacturing Based on Taxonomy

The manufacturing process for PCBAs consists of well-defined steps, and there are essential design steps that should be followed to assist your CM in building your boards. The relative importance of these design steps depends upon the taxonomy under which your PCB type can be classified. The table below illustrates the most important of these design steps applicable to board types that fall under a given taxonomy.

OPTIMAL MANUFACTURING FOR DIFFERENT TYPES OF PCBs
TAXONOMIES	OPTIMAL MANUFACTURING DESIGN TIPS
Mechanical Construction	Place component locations well away from any flex areas Choose materials that meet IPC bending requirements Understand board parameters and utilize them for board selection
Stackup	Use the minimum number of layers that is adequate for the layout Choose materials that can withstand successive bonding Use the least complex via routing
Application	Perform thermal analysis and ensure boards can withstand temperature conditions of their operating environment Use radiation-hardened enclosure instead of radiation-hardened components for aerospace boards Apply adequate finishing for industrial boards
Signals and Power	Follow CM DFM clearance recommendations Route parallel traces on the same layer Follow NEC guidelines for cabling and connectors Only use heavy copper traces when necessary

The design steps listed above are not all-inclusive for the taxonomies listed. However, it is highly recommended that these are included as part of your design process in order to provide the best aid to your CM and the manufacturing process.