What factors affect the cost of PCB manufacturing? This is a topic of great interest to everyone involved in PCB industry. It is also one of the most frequently mentioned topics in the customer feedback NCAB receives. In this column, we’ll take a closer look at what factors determine the hard cost of PCB manufacturing.

Overall, 80% to 90% of the total COST of a PCB is actually concentrated in the upper part of the supply chain, before the supplier (EMS plant, PCB manufacturer, etc.) sees the final design of the PCB. We can divide the cost factors of PCB manufacturing into two broad categories — “hard cost factors” and “hidden cost factors”.

As for the hard cost factor of PCB manufacturing, it must include some basic cost factors, such as the size of PCB. It is well known that the larger the size of a PCB, the more material is required, thus increasing the cost. If we use a base 2L plate size of 2×2″ as a baseline, then increasing the size to 4×4″ would increase the cost of the base material by a factor of 4. Material requirements are not only a factor on the X and Y axes, but also on the Z axis. This is because each core board added to the lamination requires additional materials, plus material handling, printing and etching, AOI inspection, chemical cleaning and Browning costs, so adding layers increases the final product cost.

At the same time, the choice of materials will also affect the cost, the cost of advanced plates (M4, M6, etc.) is higher than that of ordinary FR4. In general, we recommend that customers specify a particular sheet with the option of “or equivalent material”, so that the factory can properly allocate the use of materials to meet the needs of the customer and avoid a long sheet procurement cycle.

The complexity of a PCB also affects the cost. When standard multilaminates are used and blind, buried, or blind hole designs are added, the cost is bound to increase. Engineers need to be aware that the use of a buried hole structure not only increases the drilling cycle, but also increases the duration of the compression. In order to make blind holes, the circuit board must be pressed, drilled and electroplated many times, resulting in increased production costs.

Another important factor to consider is the jigsaw puzzle. The way of assembling the board will affect the utilization rate of the material. If it is not necessary, there will be too much space between the board and the process edge, which will cause the waste of the board. In fact, minimizing the space between the boards and the size of the process edge can improve the utilization of the board. If the circuit board is designed as a square or rectangle, v-cut with “0” spacing will maximize the use of boards.

Line width line spacing is also one of the factors affecting the cost. The smaller the line width and line distance, the higher the requirements of the factory process capacity, the more difficult the production, the more likely to appear waste board. If the circuit board design is long or looped, the likelihood of failure increases and the cost increases.

The number and size of holes also affect the cost. Too small or too many holes can increase the cost of the circuit board. Smaller bits also have smaller chip slots, limiting the number of circuit boards that can be drilled in a single drill cycle. The short length of the bit’s grooves also limits the number of circuit boards that can be drilled at one time. Because CNC drilling machines require multiple operations, labor costs can also rise. In addition, the aperture ratio needs to be considered. Drilling small holes in thick plates also increases the cost and requires the manufacturing capacity of the factory.

The final hard cost factor is PCB surface treatment. Special finishes such as hard gold, thick gold or nickel palladium can add further costs. All in all, the choices you make during the PCB design phase can affect the final manufacturing cost of the PCB. NCAB recommends that PCB suppliers be involved in product design as early as possible to prevent unnecessary cost wastage later.