The world of technology has been revolutionized since the introduction of PCBs.
Printed Circuit Boards, or PCBs, are essentially circuit boards that were first invented in the 20th century, with its use becoming widespread everywhere.
When it comes to PCB production, one of the most important steps, is that of prototyping.
It is the term used to refer to the initial models that are produced before full-scale production is begun.
This is necessary, in order to test the viability and stability of the product, as well as ensure that the client requirements are met before large scale orders are put into production.
Some of the recommendations for selecting the correct PCB Prototype thickness are mentioned in the points below.
Table of Contents
1. The Material of Choice
The material used for the circuitry plays a key role in the PCBs thickness.
One of the determinants of thickness in PCBs, is the metal used for the conducting layer.
For the most part, copper has been the metal of choice, given its ability to conduct electricity with ease. At the same time, however, other materials have also been used as well, such as aluminum.
And these materials, in turn, have variable properties, which have an effect on the final thickness being selected for the PCB.
2. The Number of Layers
The next thing to take into consideration would be the number of layers.
PCBs, in general, come in several varieties, ranging from single to dual and even multiple layers, each with their own set of applications. Indeed, one could say that there are several different varieties of PCBs, depending on the needs of the client and business.
In general, boards that use multiple layers tend to use metals of lower thickness, while those that are designed with one or two layers have a thicker one. Also, another thing which can be taken as a rule is that the greater the number of layers being used, the thicker the final PCB is going to be.
3. The Standard Thickness
When it comes to the manufacture of PCBs, there is a minimum amount of thickness that is prescribed for the boards.
It is a requirement suggested in order to maintain the stability of operations and smooth functioning of the components. These, however, may vary depending on the exact requirements.
As a general rule, the minimum required thickness for the PCBs is 1.57 mm and has been the general norm for a very long time. At the same time, however, the changing times, along with shifts in materials and manufacturing processes, have resulted in a thickness of 0.2, 0.5 or 0.4 mm is used as well. In addition to this, thicknesses on the other end of the spectrum, with some as high as 2.36 and 3.175 mm have been used as well.
4. The Trace Thickness
A trace is the equivalent of wire in the transmitting of signals in a PCB. Every single trace has a single flat, narrow part of the copper or other metal foil which remains after it has been etched to create the circuit on the PCB.
The thicknesses of these traces will vary from PCB to PCB, with signal traces being generally narrower in comparison to power or ground traces, due to the variability of the current being carried in it.
These differences in trace thickness, in turn, will affect the thickness of the final PCB.
5. The Application
A PCB is at the end of the day an electronic component and nothing more.
It is but a piece of the puzzle in a larger piece of equipment, where it comes together with other components to serve a purpose.
This is something that is to be taken into account as well, where the size of the final component will have an effect on the thickness of the PCB.
For example, the PCBs in televisions can have a higher degree of thickness, while the ones used in smartphones need PCBs that are relatively thin, due to the space considerations.
6. Finishing Required
Finishing can be thought of as the final layer that is applied after the manufacturing process is completed.
Typically, the layers are that of metals such as lead or gold, although others may be used as well. The reason for the doing so, ranging from preservation of the component’s assemblies to overall structural stability.
In this regard, the thickness of the metal used will have an impact on the kind of finishing that can be used. In other words, there is a minimum amount of thickness required in the components of the PCBs, before a certain finish can be applied.
For example, the application of a gold finish on a PCB requires that the metal’s thickness be 0.2 mm of minimum thickness, meaning that anything less will prevent the finishing from properly bonding to the board’s surface.
7. Budgetary Constraints
As with anything that is produced, there are always budgetary constraints in any industry.
There is always a certain limitation when it comes to any project. This will have an important role in the way it is executed, ranging from the raw materials purchased, to the labor used and everything in between.
And this certainly will have an effect on the thickness as well. Given that, especially in bulk orders, every extra millimeter of thickness will add up to the final bill, and often create a difference by a vast margin, budgetary constraints are an important thing to be taken into consideration.
At the same time, it should also be added the limitations on thickness should also take into account the minimum requirements for the PCBs as well.
8. Manufacturer and Client Specifications
The last but not the least has to do more with the manufacturer and client, than the technology itself.
For example, different manufacturers have their own standards, when it comes to determining the final thickness of the PCBs.
Likewise, different clients tend to provide their own set of requirements, regarding how thick the final PCB ought to be.
In all, the above list of points is some of the main considerations, when it comes to selecting the ideal thickness for the PCB prototype.
Furthermore, it should also be noted that the above factors tend to combine together when determining the final thickness, as opposed to being individual and unique factors.
It should, however, be noted, that depending on the design, requirements, and construction, these factors can and will change as well.
Related Reading: Introduction to PCB Prototype Assembly