When calculating the manufacturing cost of every PCB, there are several key factors that combined and affect the overall cost together, commonly concluded as fabrication specifications:
Material, board thickness, layer counts, copper weight(or thickness), surface finish, solder mask, dimension.
And there are other processing requirements that influence the cost as well: diameter of vias and trace width&spacing.
With notions of these specifications will help engineers&procurement teams to understand the structure of overall cost and how to calculate, and balancing cost with production constraints when need to reduce the manufacturing cost. For more explanations, please proceed for detailed below:
1. PCB Material
Material of substrate has a significant impact on PCB cost:
Standard FR-4 is most widely applied for PCBs, from consumer electronics to industry automation, from medical device to telecommunication carriers.
And for some industries and special appliance, such as RF, then have to apply other materials, such as high-frequency material Rogers RO4003C for radar.
And materials like polyimide(shorted as PI) for FPC(flexible printed circuit) and it is widely applied on smartphones and medical devices as conductive wires, and metal-core substrates typically applied for high-electrical current such as for new energy equipment, like EV charging station.
2. PCB Copper Weight(or Thickness)
Copper weight affects both material cost and manufacturing processes. Copper weight such as 1 OZ is widely applied, but for some electronics, the copper weight have to increase to coordinate with the electrical current, more current flows then more thicker the copper layer is, then require more strict control of the etching process.
3. PCB Layer Count
PCB is fabricated by lamination(see stackup), more layers would require more process of lamination, drilling, and inspection. HDI structures and complex multilayer designs often require advanced manufacturing capabilities and rigorous process control.
4. PCB Dimension
PCB dimension affects the price directly: the bigger the PCB board is, of course the price is higher, also the dimension influence raw-material utilization and production efficiency especially when panelize the boards. Optimizing panel layout could reduce material waste and lower the cost per PCB, especially in high-volume production.
5. PCB Vias
Processing approaches such as blind vias, buried vias, microvias, they require various processings and setup, tools, time and influcence the cost, they increase cost due to strict processing requirements.
6. PCB Surface Finishes
Surface finishes such as HASL, Lead Free-HASL, OSP, ENIG, ENEPIG, Immersion Silver, Immersion Tin, Hard Gold, etc, they affect the overall cost significantly.
Nowadays, the most commonly applied is Lead-Free HASL, and the second-widely applied is ENIG but the price is expensive around 2-3 times than Lead Free HASL. The most cheap option is OSP and the most expensive process is ENEPIG.
7. PCB Trace Width and Spacing
Finer the trace width and spacing, higher the requirement of manufacturing precision, and rigorous process control, such as 4/4 mil trace/space would require advanced fabrication capabilities compared with standard width 0.2mm.
For engineers and procurement teams who are looking for PCB manufacturer and have a plan to order PCB, it would help a lot with understanding of structure of PCB cost and the differences of specifications.
If you are looking for a reliable PCB manufacturer, here I recommend Kyrid, it is good at PCB fabrication and keeps the quotation structure&item transparent, you can know the difference of each specification options and make the most ideal decision.
Also Kyrid provides engineering examination service with proposals, to support you PCB order and manufacturing goes smoothly.
