When I hear the word “standard,” I think of the benchmark by which all other similar things should be judged. For example, the Cadillac was long considered the gold standard among automobiles. For many, it still is. Now, the standard can also refer to a standard size. For instance, the standard width for a couch built to seat three people is 84 in or 8 ft. When referring to the dimensions of a product, the standard can be very important as it may have attributes or functions that it must satisfy.
For circuit boards, the thickness is a very important standard. Consequently, even though there is not a single “official” standard, there are sizes that are common and preferred. In some cases, your contract manufacturer (CM) may advise you to adhere to one of these standards in order to tailor your design to the capabilities of their equipment, lower costs, and/or minimize turnaround time for your boards. Let’s first take a look at standard PCB thickness and then discuss what we should consider before opting for a non-standard or custom PCB thickness.
What is Standard PCB Thickness?
Many contract manufacturers may say that the standard PCB thickness is 1.57 mm, or approximately 0.062 in. This is true to an extent. Apparently, this was the size that bakelite sheets were manufactured in during the earlier days of board fabrication and the size has stuck. Therefore, we can refer to this as the historical standard PCB thickness. Today, boards are made to be larger and smaller than this standard, but the standard probably remains the most common thickness for designs.
Today, it is more accurate to say there is a range of common or standard PCB thicknesses. These include 0.031in (0.78mm ), 0.062in (1.57mm) and 0.093in (2.36mm). Depending on your choice for PCB fabrication and assembly services, you may be able to have boards made with other thicknesses. When determining the PCB thickness, there a number of design and manufacturing factors to consider, as listed below.
Design Factors that Impact PCB Thickness
- Copper thickness
- Board materials
- Number of PCB layers
- Signal types
- Types of vias
- Operating environment
Manufacturing Factors that Impact PCB Thickness
What If I Want a Custom Thickness?
PCBs are manufactured in sheets or panels that come readily available in common sizes. More than likely, your CM either has these in stock or can quickly obtain them. Other sizes may be available but are restricted by your CM’s equipment processing capabilities, not to mention the delay or back-order time to acquire them. Similarly, if your design calls for an uncommon board thickness, you may be restricted by your CM’s equipment capabilities and slowed down by the time required to procure the sheets or panels from the manufacturer. These factors, along with the others listed below, should be considered if you opt for a custom PCB thickness.
Factors to Consider for Custom PCB Thickness
Factor 1: CM’s equipment capabilities
The first consideration is whether your CM has the equipment to manufacture the board thickness you need. This determination should be made early during the design process, along with other design for manufacturing (DFM) requirements. Otherwise, you may be forced to make modifications and redesign your PCB layout.
Factor 2: Extended turnaround time
There is often a delay involved in acquiring an uncommon PCB thickness. You should consider how this will impact your development quality and delivery schedule.
Factor 3: Additional cost
Last but certainly not least, you need to evaluate the additional costs for the special materials, manufacturing, and any lost man-hours to determine if the additional costs are acceptable.
At times, it is best to follow the standard course, and at others, it is better to customize. When it comes to PCB thickness, you do have a choice. Using a standard PCB thickness will most likely result in faster and less expensive manufacture of your boards. However, if you opt for a custom thickness, then you should ensure that your CM possesses the specific capabilities your design may require.
|Tempo‘s Custom PCB Manufacturing Service
At Tempo Automation, the industry leader in fast, high-quality prototype and low volume PCB manufacturing, we are committed to meeting your design intent and objectives, whether standard or custom.
And to help you get started on the best path, we furnish information for your DFM checks and enable you to easily view and download DRC files. If you’re an Altium user, you can simply add these files to your PCB design software.
If you are ready to have your design manufactured, try our quote tool to upload your CAD and BOM files. If you want more information on standard PCB thickness or factors to consider for custom PCB thickness, contact us.